Taspoglutide, an analog of human glucagon-like Peptide-1 with enhanced stability and in vivo potency.
Sebokova Elena,Christ Andreas D,Wang Haiyan,Sewing Sabine,Dong Jesse Z,Taylor John,Cawthorne Michael A,Culler Michael D
Taspoglutide is a novel analog of human glucagon-like peptide-1 [hGLP-1(7-36)NH2] in clinical development for the treatment of type 2 diabetes. Taspoglutide contains alpha-aminoisobutyric acid substitutions replacing Ala(8) and Gly(35) of hGLP-1(7-36)NH2. The binding affinity [radioligand binding assay using [(125)I]hGLP-1(7-36)NH2], potency (cAMP production in CHO cells stably overexpressing hGLP-1 receptor), and in vitro plasma stability of taspoglutide compared with hGLP-1(7-36)NH2 have been evaluated. Effects on basal and glucose-stimulated insulin secretion were determined in vitro in INS-1E cells and in vivo in normal rats. Taspoglutide has comparable affinity (affinity constant 1.1 +/- 0.2 nm) to the natural ligand (affinity constant 1.5 +/- 0.3 nm) for the hGLP-1 receptor and exhibits comparable potency in stimulating cAMP production (EC(50) Taspo 0.06 nm and EC(50) hGLP-1(7-36)NH2 0.08 nm). Taspoglutide exerts insulinotropic action in vitro and in vivo and retains the glucoincretin property of hGLP-1(7-36)NH2. Stimulation of insulin secretion is concentration dependent and evident in the presence of high-glucose concentrations (16.7 mm) with a taspoglutide concentration as low as 0.001 nm. Taspoglutide is fully resistant to dipeptidyl peptidase-4 cleavage (during 1 h incubation at room temperature with purified enzyme) and has an extended in vitro plasma half-life relative to hGLP-1(7-36)NH2 (9.8 h vs. 50 min). In vitro, taspoglutide does not inhibit dipeptidyl peptidase-4 activity. This study provides the biochemical and pharmacological basis for the sustained plasma drug levels and prolonged therapeutic activity seen in early clinical trials of taspoglutide. Excellent stability and potency with substantial glucoincretin effects position taspoglutide as a promising new agent for treatment of type 2 diabetes.
Strong reproductive skew among males in the multiply mated swordtail Xiphophorus multilineatus (Teleostei).
Luo J,Sanetra M,Schartl M,Meyer A
The Journal of heredity
Male swordtails in the genus Xiphophorus display a conspicuous ventral elongation of the caudal fin, the sword, which arose through sexual selection due to female preference. Females mate regularly and are able to store sperm for at least 6 months. If multiple mating is frequent, this would raise the intriguing question about the role of female choice and male-male competition in shaping the mating system of these fishes. Size-dependent alternate mating strategies occur in Xiphophorus; one such strategy is courtship with a sigmoid display by large dominant males, while the other is gonopodial thrusting, in which small subordinate males sneak copulations. Using microsatellite markers, we observed a frequency of multiple paternity in wild-caught Xiphophorus multilineatus in 28% of families analyzed, but the actual frequency of multiple mating suggested by the correction factor PrDM was 33%. The number of fathers contributing genetically to the brood ranged from one to three. Compared to other species in the family Poeciliidae, both frequency and degree of multiple paternity were low. Paternity was found to be highly skewed, with one male on average contributing more than 70% to the offspring. Hence in this Xiphophorus mating system, typically one male dominates and sneaker males do not appear to be particularly effective. Postcopulatory mechanisms, however, such as sperm competition, are also indicated by our data, using sex-linked phenotypes among the offspring.
PRISM/PRDM6, a transcriptional repressor that promotes the proliferative gene program in smooth muscle cells.
Davis Christopher A,Haberland Michael,Arnold Michael A,Sutherland Lillian B,McDonald Oliver G,Richardson James A,Childs Geoffrey,Harris Stephen,Owens Gary K,Olson Eric N
Molecular and cellular biology
Smooth muscle cells (SMCs) display remarkable phenotypic diversity and plasticity and can readily switch between proliferative and differentiated states in response to extracellular cues. In an effort to identify novel transcriptional regulators of smooth muscle phenotypes, we compared the gene expression profiles of arterial and venous SMCs by microarray-based transcriptional profiling. Among numerous genes displaying distinct expression patterns in these two SMC types, we discovered an expressed sequence tag encoding a previously uncharacterized zinc finger protein belonging to the PRDM (PRDI-BF1 and RIZ homology domain) family of chromatin-remodeling proteins and named it PRISM (PR domain in smooth muscle). PRISM is expressed in a variety of smooth muscle-containing tissues and displays especially robust expression in the cardiac outflow tract and descending aorta during embryogenesis. PRISM is localized to the nucleus and contains an amino-terminal PR domain and four Krüppel-like zinc fingers at the carboxy terminus. We show that PRISM acts as a transcriptional repressor by interacting with class I histone deacetylases and the G9a histone methyltransferase, thereby identifying PRISM as a novel SMC-restricted epigenetic regulator. Overexpression of PRISM in cultured primary SMCs induces genes associated with the proliferative smooth muscle phenotype while repressing regulators of differentiation, including myocardin and GATA-6. Conversely, small interfering RNA-mediated knockdown of PRISM slows cell growth and induces myocardin, GATA-6, and markers of SMC differentiation. We conclude that PRISM acts as a novel epigenetic regulator of SMC phenotypic plasticity by suppressing differentiation and maintaining the proliferative potential of vascular SMCs.
PRDM1/BLIMP-1 expression in multiple B and T-cell lymphoma.
Garcia José-Francisco,Roncador Giovanna,García Juan-Fernando,Sánz Ana-Isabel,Maestre Lorena,Lucas Elena,Montes-Moreno Santiago,Fernandez Victoria Rebeca,Martinez-Torrecuadrara Jorge L,Marafioti Teresa,Mason David Y,Piris Miguel A
BACKGROUND AND OBJECTIVES:The positive regulatory domain I (PRDM1) protein or BLIMP-1, belonging to the PRDM gene family of transcriptional repressors, is a key regulator of terminal differentiation in B-lymphocytes and is critical for plasma cell differentiation. DESIGN AND METHODS:Here we document the expression of PRDM1 in normal and neoplastic lymphoid cells, through the use of a monoclonal antibody that recognizes the molecule in paraffin-embedded tissue sections. A large series of B and T-cell lymphomas (679 cases) was studied, using tissue microarrays. RESULTS:Multiple myeloma, plasmacytoma and lymphoplasmacytic lymphoma cases (n=19) were positive. Plasmablastic lymphoma, oral mucosa-type (n=15), were also found to be positive. PRDM1 protein was expressed in some cases of B-cell neoplasia, i.e. chronic lymphocytic leukemia/small lymphocytic lymphoma (15%), diffuse large B-cell lymphoma (43%), classical Hodgkin's lymphoma (41%) and also in T-cell lymphoma (23%). INTERPRETATION AND CONCLUSIONS:Most B-neoplastic cells showing plasmablastic differentiation were PRDM1-positive. Unexpectedly, a subset of diffuse large B-cell lymphoma expressed PRDM1, lacked detectable plasmablastic or immunoblastic changes and displayed more aggressive behavior, with a shorter failure-free survival. In contrast to normal B-cells, diffuse large B-cell lymphoma cases with increased PRDM1 expression co-expressed BCL-6 and MUM1/IRF4, confirming that PRDM1 expression in these tumors is insufficient to drive the full genetic program associated with plasmacytic differentiation.
Blimp-1Deltaexon7: a naturally occurring Blimp-1 deletion mutant with auto-regulatory potential.
Schmidt Doris,Nayak Arnab,Schumann Julia E,Schimpl Anneliese,Berberich Ingolf,Berberich-Siebelt Friederike
Experimental cell research
Blimp-1 is a master regulator of terminal B cell differentiation and plays a pivotal role in various developmental processes. In addition to full length Blimp-1, a Blimp-1 mRNA lacking exon 7 (Blimp-1Delta7) has been described to occur in murine B cells. The activity and function of the mutant mRNA-encoded protein (Blimp-1Delta7), lacking three crucial zinc fingers necessary for DNA interaction, is completely unknown. Since isoforms of other prdm family proteins affect each other's functions, we wondered whether Blimp-1Delta7 still plays a role in B cells, independent of direct DNA binding. In this study, we found that Blimp-1Delta7 is preferentially expressed in naïve CD19(+) B cells. A fraction of Blimp-1Delta7 migrates to the nucleus, colocalizes with HDAC2 and is found at sites of repressed chromatin, although it does not bind to the Blimp-1 DNA consensus site. Unexpectedly, Blimp-1 and Blimp-1Delta7 homodimerize as well as heterodimerize with each other. Ectopic expression of Blimp-1Delta7 in WEHI 231 cells, a Blimp-1-negative murine lymphoma line, leads to cessation of proliferation and enhancement of apoptosis. Importantly, LPS-induced differentiation is suppressed in the presence of Blimp-1Delta7. This is in agreement with our finding that Blimp-1Delta7 interferes with endogenous Blimp-1 expression. Thus, our data suggest an auto-regulatory mechanism of Blimp-1 activation.
The tumor suppressor PRDM5 regulates Wnt signaling at early stages of zebrafish development.
Meani Natalia,Pezzimenti Federica,Deflorian Gianluca,Mione Marina,Alcalay Myriam
PRDM genes are a family of transcriptional regulators that modulate cellular processes such as differentiation, cell growth and apoptosis. Some family members are involved in tissue or organ maturation, and are differentially expressed in specific phases of embryonic development. PRDM5 is a recently identified family member that functions as a transcriptional repressor and behaves as a putative tumor suppressor in different types of cancer. Using gene expression profiling, we found that transcriptional targets of PRDM5 in human U2OS cells include critical genes involved in developmental processes, and specifically in regulating wnt signaling. We therefore assessed PRDM5 function in vivo by performing loss-of-function and gain-of-function experiments in zebrafish embryos. Depletion of prdm5 resulted in impairment of morphogenetic movements during gastrulation and increased the occurrence of the masterblind phenotype in axin+/- embryos, characterized by the loss of eyes and telencephalon. Overexpression of PRDM5 mRNA had opposite effects on the development of anterior neural structures, and resulted in embryos with a shorter body axis due to posterior truncation, a bigger head and abnormal somites. In situ hybridization experiments aimed at analyzing the integrity of wnt pathways during gastrulation at the level of the prechordal plate revealed inhibition of non canonical PCP wnt signaling in embryos overexpressing PRDM5, and over-activation of wnt/beta-catenin signaling in embryos lacking Prdm5. Our data demonstrate that PRDM5 regulates the expression of components of both canonical and non canonical wnt pathways and negatively modulates wnt signaling in vivo.
An expanding job description for Blimp-1/PRDM1.
Bikoff Elizabeth K,Morgan Marc A,Robertson Elizabeth J
Current opinion in genetics & development
The master transcriptional regulator Blimp-1/PRDM1 contains an N-terminal PR/SET domain and five C2H2 zinc fingers located near its C-terminus that mediate DNA binding, nuclear import and recruitment of histone modifying enzymes. These activities account for its ability to control cell-fate decisions in the embryo and govern tissue homeostasis in multiple cell types in the adult organism. New experiments demonstrate an increasing degree of complexity associated with Blimp-1/PRDM1 target site selection and its associations with epigenetic modifiers. Our current understanding of how this single unique species within the family of structurally similar PRDM proteins regulates gene expression patterns and governs developmental programmes in different cell lineages is discussed.
Histone methyltransferase PRDM8 regulates mouse testis steroidogenesis.
Eom Gwang Hyeon,Kim Kabsun,Kim Sung-Mi,Kee Hae Jin,Kim Ji-Young,Jin Hye Mi,Kim Ju-Ryoung,Kim Jung Ha,Choe Nakwon,Kim Kee-Beom,Lee Junwon,Kook Hyun,Kim Nacksung,Seo Sang-Beom
Biochemical and biophysical research communications
A family of PRDM proteins are similar to histone methyltransferases (HMTases) with SET domain in that they modulate different cellular processes, including transcriptional regulation, through chromatin modifying activities. By applying a bioinformatic approach, we searched for proteins containing the SET domain and identified a double zinc-finger domain containing PRDM8 with HMTase activity. In vitro HMTase assay and immunoblot analysis revealed that PRDM8 specifically methylates H3K9 of histones which indicates transcriptional repression activity of PRDM8. Direct recruitment of PRDM8 to the promoter mediated transcriptional repression and indicated no involvement of HDAC. Tissue blot analyses identified PRDM8 transcripts from brain and testis in adult mouse. Consistent with these observations, we demonstrate that PRDM8 repressed the expression of steroidogenic markers, p450c17c and LHR, which indicates its regulatory role in mouse testis development.
DNA methylation and carcinogenesis of PRDM5 in cervical cancer.
Cheng Hai-Yan,Chen Xiu-Wei,Cheng Li,Liu Yun-Duo,Lou Ge
Journal of cancer research and clinical oncology
OBJECTIVE:PR (PRDI-BF1 and RIZ) domain proteins (PRDM) are a subfamily of the kruppel-like zinc finger gene products and play key roles during cell differentiation and malignant transformation. PRDM5 (PR domain containing 5 PFM2) is a new PR-domain-containing gene. The purpose of the present study was to examine the expression of PRDM5 and evaluate its carcinogenesis in cervical cancer. The relationship between DNA methylation and transcriptional silencing of PRDM5 was investigated in cervical cancer. METHODS:PRDM5 expression was examined in cervical cancer cell lines and cervical tissues (12 normal and 42 cancerous) by using RT polymerase chain reaction (PCR). Methylation status of the PRDM5 promoter was studied using methylation-specific PCR (MSP). RESULTS:PRDM5 expression is reduced or lost in cervical cancers, compared with normal cervical tissues (P < 0.05). The current study results also showed that loss of PRDM5 is mediated by aberrant cytosine methylation of the PRDM5 promoter. There were 40.5% of carcinomas methylated, while none of normal tissues were methylated. PRDM5 mRNA expression was significantly higher (P = 0.000) in unmethylated (0.2634 ± 0.0674, mean ± SD), compared with methylated tissues (0.1007 ± 0.0993, mean ± SD). Last, treatment with a DNA methyltransferase inhibitor led to reactivation of PRDM5 expression in cell lines that had negligible PRDM5 expression at baseline. CONCLUSIONS:Reduced expression of PRDM5 may play an important role in the pathogenesis and/or development of cervical cancer, and is considered to be caused in part by aberrant DNA methylation.
Follicular dendritic cell-induced microRNA-mediated upregulation of PRDM1 and downregulation of BCL-6 in non-Hodgkin's B-cell lymphomas.
Lin J,Lwin T,Zhao J-J,Tam W,Choi Y S,Moscinski L C,Dalton W S,Sotomayor E M,Wright K L,Tao J
B-cell lymphoma 6 (BCL6) and PR domain containing 1 (PRDM1) are considered as master regulators for germinal center (GC) formation and terminal B-cell differentiation. Dysregulation of BCL6 and PRDM1 has been associated with lymphomagenesis. Here, we show for the first time that direct cell-cell contact between follicular dendritic cells (FDC) and B-lymphocytes, by influencing the expression of a set of microRNAs (miRNAs), regulates the expression of BCL6 and PRDM1. We identify that, on cell adhesion to FDC, FDC induces upregulation of PRDM1 expression through downregulation of miR-9 and let-7 families and induces downregulation of BCL-6 through upregulation of miR-30 family in B-lymphocytes and lymphoma cells. We further demonstrate that the miR-30 family directly controls BCL-6 expression and miR-9-1 and let-7a directly control PRDM-1 expression through targeting their 3'UTR, mediating the FDC effect. Our studies define a novel regulatory mechanism in which the FDC, through induction of miRNAs in B-lymphocytes, orchestrates the regulation of transcription factors, promotes germinal center B-cell survival and differentiation. Dysregulation of miRNAs may interfere with B-cell survival and maturation, thus representing a novel molecular mechanism, as well as a potential therapeutic target in B-cell lymphomas.
Sumoylation of MEL1S at lysine 568 and its interaction with CtBP facilitates its repressor activity and the blockade of G-CSF-induced myeloid differentiation.
Nishikata I,Nakahata S,Saito Y,Kaneda K,Ichihara E,Yamakawa N,Morishita K
MEL1 (MDS1/EVI1-like gene 1/PRDM16), which was identified as a gene near the chromosomal breakpoint in t(1;3)(p36;q21)-positive human acute myeloid leukemia cells, belongs to the PRDI-BF1-RIZ1 homologous (PR) domain (PRDM) family of transcription repressors. The short form of MEL1 (MEL1S), which lacks the PR-domain at the N-terminus, is the main form expressed in t(1;3)(p36;q21)-positive acute myeloid leukemia cells. The overexpression of MEL1S blocks granulocyte colony-stimulating factor (G-CSF)-induced myeloid differentiation in interleukin-3-dependent murine myeloid L-G3 cells. In this study, we show that treatment with the histone deacetylase inhibitor trichostatin A abolished the blockade of myeloid differentiation in L-G3 cells overexpressing MEL1S. The expression of MEL1S containing mutated CtBP-interacting motif (CIM) in L-G3 cells still blocked the myeloid differentiation induced by G-CSF. We found that the small ubiquitin-related modifier (SUMO) motif (SM) at lysine 568 (VKAE) adjacent to the CIM was necessary to obtain the maximum transcriptional repressor activity of MEL1S. L-G3 cells expressing MEL1S, and bearing mutated CIM and SM differentiated into granulocytes in response to G-CSF; this indicated that both the SUMO modification at lysine 568 and CtBP binding were required for MEL1S-mediated transcriptional repression and blockade of differentiation, which might be relevant for the process of leukemogenesis.
B cells are critical to T-cell-mediated antitumor immunity induced by a combined immune-stimulatory/conditionally cytotoxic therapy for glioblastoma.
Candolfi Marianela,Curtin James F,Yagiz Kader,Assi Hikmat,Wibowo Mia K,Alzadeh Gabrielle E,Foulad David,Muhammad A K M G,Salehi Sofia,Keech Naomi,Puntel Mariana,Liu Chunyan,Sanderson Nicholas R,Kroeger Kurt M,Dunn Robert,Martins Gislaine,Lowenstein Pedro R,Castro Maria G
Neoplasia (New York, N.Y.)
We have demonstrated that modifying the tumor microenvironment through intratumoral administration of adenoviral vectors (Ad) encoding the conditional cytotoxic molecule, i.e., HSV1-TK and the immune-stimulatory cytokine, i.e., fms-like tyrosine kinase 3 ligand (Flt3L) leads to T-cell-dependent tumor regression in rodent models of glioblastoma. We investigated the role of B cells during immune-mediated glioblastoma multiforme regression. Although treatment with Ad-TK+Ad-Flt3L induced tumor regression in 60% of wild-type (WT) mice, it completely failed in B-cell-deficient Igh6(-/-) mice. Tumor-specific T-cell precursors were detected in Ad-TK+Ad-Flt3L-treated WT mice but not in Igh6(-/-) mice. The treatment also failed in WT mice depleted of total B cells or marginal zone B cells. Because we could not detect circulating antibodies against tumor cells and the treatment was equally efficient in WT mice and in mice with B-cell-specific deletion of Prdm 1 (encoding Blimp-1), in which B cells are present but unable to fully differentiate into antibody-secreting plasma cells, tumor regression in this model is not dependent on B cells' production of tumor antigen-specific immunoglobulins. Instead, B cells seem to play a role as antigen-presenting cells (APCs). Treatment with Ad-TK+Ad-Flt3L led to an increase in the number of B cells in the cervical lymph nodes, which stimulated the proliferation of syngeneic T cells and induced clonal expansion of antitumor T cells. Our data show that B cells act as APCs, playing a critical role in clonal expansion of tumor antigen-specific T cells and brain tumor regression.
Prdm5 regulates collagen gene transcription by association with RNA polymerase II in developing bone.
Galli Giorgio Giacomo,Honnens de Lichtenberg Kristian,Carrara Matteo,Hans Wolfgang,Wuelling Manuela,Mentz Bettina,Multhaupt Hinke Arnolda,Fog Cathrine Kolster,Jensen Klaus Thorleif,Rappsilber Juri,Vortkamp Andrea,Coulton Les,Fuchs Helmut,Gailus-Durner Valérie,Hrabě de Angelis Martin,Calogero Raffaele Adolfo,Couchman John Robert,Lund Anders Henrik
PRDM family members are transcriptional regulators involved in tissue specific differentiation. PRDM5 has been reported to predominantly repress transcription, but a characterization of its molecular functions in a relevant biological context is lacking. We demonstrate here that Prdm5 is highly expressed in developing bones; and, by genome-wide mapping of Prdm5 occupancy in pre-osteoblastic cells, we uncover a novel and unique role for Prdm5 in targeting all mouse collagen genes as well as several SLRP proteoglycan genes. In particular, we show that Prdm5 controls both Collagen I transcription and fibrillogenesis by binding inside the Col1a1 gene body and maintaining RNA polymerase II occupancy. In vivo, Prdm5 loss results in delayed ossification involving a pronounced impairment in the assembly of fibrillar collagens. Collectively, our results define a novel role for Prdm5 in sustaining the transcriptional program necessary to the proper assembly of osteoblastic extracellular matrix.
Novel SNPs in the PRDM16 gene and their associations with performance traits in chickens.
Han Ruili,Wei Yang,Kang Xiangtao,Chen Hong,Sun Guirong,Li Guoxi,Bai Yichun,Tian Yadong,Huang Yanqun
Molecular biology reports
The PR domain containing 16 (PRDM16) is a member of the Prdm family, and is known to regulate cell differentiation. In the present study, DNA pool sequencing methods were employed to screen genetic variations in the chicken PRDM16 gene. The results revealed four novel single nucleotide polymorphisms (SNPs): NC_006108.2: g.92188G>A, XM_417551: c.1161C>T (Ala/Ala, 387aa), c.1233C>T (Ser/Ser, 411aa) and c.1433G>A (Ser/Asn, 478aa). The BglI polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to detect c.1161C>T, while HhaI Forced PCR-RFLP methods were used to detect 1233C>T and c.1433G>A in 964 chickens. The chickens comprised 38 grandparents, 66 F(1) parents and 860 F(2) birds derived from an F(2) resource population of Gushi chickens crossed with Anka broilers. The associations of the polymorphisms in the chicken PRDM16 gene with performance traits were analyzed in the 860 F(2) chickens. The results indicated that the three SNPs were significantly associated with growth, fatness and meat quality traits in the chickens. In particular, the polymorphisms of the missense SNP (c.1433G>A) had positive effects on chicken body weight and body size at different stages. It affected also fatness traits significantly. Comparison of the different genotypes of c.1433G>A showed that the GG genotype favored chicken growth and fatness traits.
Prdm12 is induced by retinoic acid and exhibits anti-proliferative properties through the cell cycle modulation of P19 embryonic carcinoma cells.
Yang Chia-Ming,Shinkai Yoichi
Cell structure and function
The Prdm (PRDI-BF1-RIZ1 homologous) family is involved in cell differentiation, and several Prdms have been reported to methylate histone H3 by intrinsic or extrinsic pathways. Here, we report that Prdm12 recruits G9a to methylate histone H3 on lysine 9 through its zinc finger domains. Because of the expression of Prdm12 in the developmental nervous system, we investigated the role of Prdm12 on P19 embryonic carcinoma cells as a model system for neurogenesis. In P19 cells, Prdm12 is induced by Retinoic acid (RA). Overproduction of Prdm12 in P19 cells impairs cell proliferation and increases the G1 population accompanied by the upregulation of p27. In contrast, the knockdown of Prdm12 increases the number of cells in a suspension culture of RA-induced neural differentiation. Both the PR domain and zinc finger domains are required for the anti-proliferative activity of Prdm12. While the data in this study is based on in vitro models, the results suggest that Prdm12 is induced by the RA signaling in vivo, and may regulate neural differentiation during animal development.
Transcription factor positive regulatory domain 4 (PRDM4) recruits protein arginine methyltransferase 5 (PRMT5) to mediate histone arginine methylation and control neural stem cell proliferation and differentiation.
Chittka Alexandra,Nitarska Justyna,Grazini Ursula,Richardson William D
The Journal of biological chemistry
During development of the cerebral cortex, neural stem cells (NSCs) undergo a temporal switch from proliferative (symmetric) to neuron-generating (asymmetric) divisions. We investigated the role of Schwann cell factor 1 (SC1/PRDM4), a member of the PRDM family of transcription factors, in this critical transition. We discovered that SC1 recruits the chromatin modifier PRMT5, an arginine methyltransferase that catalyzes symmetric dimethylation of histone H4 arginine 3 (H4R3me2s) and that this modification is preferentially associated with undifferentiated cortical NSCs. Overexpressing SC1 in embryonic NSCs led to an increase in the number of Nestin-expressing precursors; mutational analysis of SC1 showed that this was dependent on recruitment of PRMT5. We found that SC1 protein levels are down-regulated at the onset of neurogenesis and that experimental knockdown of SC1 in primary NSCs triggers precocious neuronal differentiation. We propose that SC1 and PRMT5 are components of an epigenetic regulatory complex that maintains the "stem-like" cellular state of the NSC by preserving their proliferative capacity and modulating their cell cycle progression. Our findings provide evidence that histone arginine methylation regulates NSC differentiation.
Gene amplification and overexpression of PRDM14 in breast cancers.
Nishikawa Noriko,Toyota Minoru,Suzuki Hiromu,Honma Toshio,Fujikane Tomoko,Ohmura Tousei,Nishidate Toshihiko,Ohe-Toyota Mutsumi,Maruyama Reo,Sonoda Tomoko,Sasaki Yasushi,Urano Takeshi,Imai Kohzoh,Hirata Koichi,Tokino Takashi
Several genes that encode PR (PRDI-BF1 and RIZ) domain proteins (PRDM) have been linked to human cancers. To explore the role of the PR domain family genes in breast carcinogenesis, we examined the expression profiles of 16 members of the PRDM gene family in a panel of breast cancer cell lines and primary breast cancer specimens using semiquantitative real-time PCR. We found that PRDM14 mRNA is overexpressed in about two thirds of breast cancers; moreover, immunohistochemical analysis showed that expression of PRDM14 protein is also up-regulated. Analysis of the gene copy number revealed that PRDM14 is a target of gene amplification on chromosome 8q13, which is a region where gene amplification has frequently been detected in various human tumors. Introduction of PRDM14 into cancer cells enhanced cell growth and reduced their sensitivity to chemotherapeutic drugs. Conversely, knockdown of PRDM14 by siRNA induced apoptosis in breast cancer cells and increased their sensitivity to chemotherapeutic drugs, suggesting that up-regulated expression of PRDM14 may play an important role in the proliferation of breast cancer cells. That little or no expression of PRDM14 is seen in noncancerous tissues suggests that PRDM14 could be an ideal therapeutic target for the treatment of breast cancer.
Molecular basis for the regulation of the H3K4 methyltransferase activity of PRDM9.
Wu Hong,Mathioudakis Nikolas,Diagouraga Boubou,Dong Aiping,Dombrovski Ludmila,Baudat Frédéric,Cusack Stephen,de Massy Bernard,Kadlec Jan
PRDM9, a histone lysine methyltransferase, is a key determinant of the localization of meiotic recombination hot spots in humans and mice and the only vertebrate protein known to be involved in hybrid sterility. Here, we report the crystal structure of the PRDM9 methyltransferase domain in complex with a histone H3 peptide dimethylated on lysine 4 (H3K4me2) and S-adenosylhomocysteine (AdoHcy), which provides insights into the methyltransferase activity of PRDM proteins. We show that the genuine substrate of PRDM9 is histone H3 lysine 4 (H3K4) and that the enzyme possesses mono-, di-, and trimethylation activities. We also determined the crystal structure of PRDM9 in its autoinhibited state, which revealed a rearrangement of the substrate and cofactor binding sites by a concerted action of the pre-SET and post-SET domains, providing important insights into the regulatory mechanisms of histone lysine methyltransferase activity.
Prdm6 is essential for cardiovascular development in vivo.
Gewies Andreas,Castineiras-Vilarino Mercedes,Ferch Uta,Jährling Nina,Heinrich Katja,Hoeckendorf Ulrike,Przemeck Gerhard K H,Munding Matthias,Groß Olaf,Schroeder Timm,Horsch Marion,Karran E Loraine,Majid Aneela,Antonowicz Stefan,Beckers Johannes,Hrabé de Angelis Martin,Dodt Hans-Ulrich,Peschel Christian,Förster Irmgard,Dyer Martin J S,Ruland Jürgen
Members of the PRDM protein family have been shown to play important roles during embryonic development. Previous in vitro and in situ analyses indicated a function of Prdm6 in cells of the vascular system. To reveal physiological functions of Prdm6, we generated conditional Prdm6-deficient mice. Complete deletion of Prdm6 results in embryonic lethality due to cardiovascular defects associated with aberrations in vascular patterning. However, smooth muscle cells could be regularly differentiated from Prdm6-deficient embryonic stem cells and vascular smooth muscle cells were present and proliferated normally in Prdm6-deficient embryos. Conditional deletion of Prdm6 in the smooth muscle cell lineage using a SM22-Cre driver line resulted in perinatal lethality due to hemorrhage in the lungs. We thus identified Prdm6 as a factor that is essential for the physiological control of cardiovascular development.
p107 is a crucial regulator for determining the adipocyte lineage fate choices of stem cells.
De Sousa Martina,Porras Deanna P,Perry Christopher G R,Seale Patrick,Scimè Anthony
Stem cells (Dayton, Ohio)
Thermogenic (beige and brown) adipocytes protect animals against obesity and metabolic disease. However, little is known about the mechanisms that commit stem cells toward different adipocyte lineages. We show here that p107 is a master regulator of adipocyte lineage fates, its suppression required for commitment of stem cells to the brown-type fate. p107 is strictly expressed in the stem cell compartment of white adipose tissue depots and completely absent in brown adipose tissue. Remarkably, p107-deficient stem cells uniformly give rise to brown-type adipocytes in vitro and in vivo. Furthermore, brown fat programming of mesenchymal stem cells by PRDM-BF1-RIZ1 homologous domain containing 16 (Prdm16) was associated with a dramatic reduction of p107 levels. Indeed, Prdm16 directly suppressed p107 transcription via promoter binding. Notably, the sustained expression of p107 blocked the ability of Prdm16 to induce brown fat genes. These findings demonstrate that p107 expression in stem cells commits cells to the white versus brown adipose lineage.
SWI/SNF complex prevents lineage reversion and induces temporal patterning in neural stem cells.
Eroglu Elif,Burkard Thomas R,Jiang Yanrui,Saini Nidhi,Homem Catarina C F,Reichert Heinrich,Knoblich Juergen A
Members of the SWI/SNF chromatin-remodeling complex are among the most frequently mutated genes in human cancer, but how they suppress tumorigenesis is currently unclear. Here, we use Drosophila neuroblasts to demonstrate that the SWI/SNF component Osa (ARID1) prevents tumorigenesis by ensuring correct lineage progression in stem cell lineages. We show that Osa induces a transcriptional program in the transit-amplifying population that initiates temporal patterning, limits self-renewal, and prevents dedifferentiation. We identify the Prdm protein Hamlet as a key component of this program. Hamlet is directly induced by Osa and regulates the progression of progenitors through distinct transcriptional states to limit the number of transit-amplifying divisions. Our data provide a mechanistic explanation for the widespread tumor suppressor activity of SWI/SNF. Because the Hamlet homologs Evi1 and Prdm16 are frequently mutated in cancer, this mechanism could well be conserved in human stem cell lineages. PAPERCLIP:
Blimp-1 overexpression is associated with low HIV-1 reservoir and transcription levels in central memory CD4+ T cells from elite controllers.
de Masson Adèle,Kirilovsky Amos,Zoorob Rima,Avettand-Fenoel Véronique,Morin Véronique,Oudin Anne,Descours Benjamin,Rouzioux Christine,Autran Brigitte
AIDS (London, England)
OBJECTIVES:The aim of the study was to determine the molecular mechanisms underlying the quasi-equilibrium between HIV and its host in the model of functional cure represented by elite controllers who spontaneously maintain exceptionally low levels of HIV reservoirs. DESIGN:Whole-genome transcriptional study and quantification of the cell-associated HIV DNA and HIV RNA levels of the four major resting CD4 T-cell subsets in HIV-1-infected elite controllers, viremic long-term nonprogressors (vir-LTNPs), and uninfected individuals. METHODS:We compared the whole-genome transcriptional profiles (ArrayExpress accession number E-MTAB-1480) of the four major resting CD4 T-cell subsets [naive (TN), central-memory (TCM), transitional-memory (TTM), and effector-memory (TEM)] from 14 HIV-1-infected individuals including seven elite controllers (E-LTNPs) and seven vir-LTNPs, and from seven uninfected individuals. The HIV-1 cellular DNA and mRNA levels were quantified in parallel in each sorted subset. RESULTS:Host gene transcriptomes followed subset differentiation and viremia except in E-LTNPs wherein TCM, the main CD4 cell compartment, showed the highest activity with three specific signatures involving overexpression of T-cell receptor and costimulation signaling pathways, overexpression of the PRDM-1/Blimp-1 transcriptional repressor, and downmodulation of type-I IFN-related genes. Among subsets, the PRDM1/Blimp-1 upregulation was associated with lower levels of both cellular HIV-DNA and HIV mRNA levels. CONCLUSION:This unique Blimp-1 transcriptional repressor signature and the contrast between host and virus transcriptional activities in TCM from elite controllers suggest Blimp-1 might be involved in controlling the HIV reservoirs in the key TCM subset.
Peer-mentored research development meeting: a model for successful peer mentoring among junior level researchers.
Santucci Aimee K,Lingler Jennifer H,Schmidt Karen L,Nolan Beth A D,Thatcher Dawn,Polk Deborah E
Academic psychiatry : the journal of the American Association of Directors of Psychiatric Residency Training and the Association for Academic Psychiatry
OBJECTIVE:This report describes a model for the development, process, and tracking methods of a Peer-mentored Research Development Meeting (PRDM), an interdisciplinary peer mentoring program. The program was initiated in 2004 by a group of postdoctoral scholars and junior faculty from the Schools of the Health Sciences at the University of Pittsburgh. METHOD:From February 2004 through February 2006, PRDM's first five members tracked and documented their research activity (e.g., manuscripts, grants) every 4 months. The defining features of PRDM are adherence to a structured frequency and format for meetings, systematic tracking and evaluation of research development activities, and maintenance of ongoing relationships with senior mentors. RESULTS:During the 24-month data collection period, members were involved in 91 research development projects including grant applications, journal article manuscripts, book chapters, and conference abstracts. Members' productivity increased during the 24-month period, as did the efficiency and focus of the completed projects. CONCLUSION:Members increased the efficiency and focus of their research development activities during the study period. Structured peer-mentoring groups have the potential to enhance research productivity among junior investigators in research intensive environments.
Loss of PRDM11 promotes MYC-driven lymphomagenesis.
Fog Cathrine Kolster,Asmar Fazila,Côme Christophe,Jensen Klaus Thorleif,Johansen Jens Vilstrup,Kheir Tony Bou,Jacobsen Linda,Friis Carsten,Louw Alison,Rosgaard Louise,Øbro Nina Friesgaard,Marquart Hanne Vibeke,Anthonsen Kristian,Braat Arie Koen,van Lohuizen Maarten,Ralfkiaer Elisabeth,Grønbæk Kirsten,Lund Anders Henrik
The PR-domain (PRDM) family of genes encodes transcriptional regulators, several of which are deregulated in cancer. By using a functional screening approach, we sought to identify novel tumor suppressors among the PRDMs. Here we demonstrate oncogenic collaboration between depletion of the previously uncharacterized PR-domain family member Prdm11 and overexpression of MYC. Overexpression of PRDM11 inhibits proliferation and induces apoptosis. Prdm11 knockout mice are viable, and loss of Prdm11 accelerates MYC-driven lymphomagenesis in the Eµ-Myc mouse model. Moreover, we show that patients with PRDM11-deficient diffuse large B-cell lymphomas (DLBCLs) have poorer overall survival and belong to the nongerminal center B-cell-like subtype. Mechanistically, genome-wide mapping of PRDM11 binding sites coupled with transcriptome sequencing in human DLBCL cells evidenced that PRDM11 associates with transcriptional start sites of target genes and regulates important oncogenes such as FOS and JUN. Hence, we characterize PRDM11 as a putative novel tumor suppressor that controls the expression of key oncogenes, and we add new mechanistic insight into B-cell lymphomagenesis.
Deficiency of Prdm13, a dorsomedial hypothalamus-enriched gene, mimics age-associated changes in sleep quality and adiposity.
Satoh Akiko,Brace Cynthia S,Rensing Nick,Imai Shin-Ichiro
The dorsomedial hypothalamus (DMH) controls a number of essential physiological responses. We have demonstrated that the DMH plays an important role in the regulation of mammalian aging and longevity. To further dissect the molecular basis of the DMH function, we conducted microarray-based gene expression profiling with total RNA from laser-microdissected hypothalamic nuclei and tried to find the genes highly and selectively expressed in the DMH. We found neuropeptide VF precursor (Npvf), PR domain containing 13 (Prdm13), and SK1 family transcriptional corepressor (Skor1) as DMH-enriched genes. Particularly, Prdm13, a member of the Prdm family of transcription regulators, was specifically expressed in the compact region of the DMH (DMC), where Nk2 homeobox 1 (Nkx2-1) is predominantly expressed. The expression of Prdm13 in the hypothalamus increased under diet restriction, whereas it decreased during aging. Prdm13 expression also showed diurnal oscillation and was significantly upregulated in the DMH of long-lived BRASTO mice. The transcriptional activity of the Prdm13 promoter was upregulated by Nkx2-1, and knockdown of Nkx2-1 suppressed Prdm13 expression in primary hypothalamic neurons. Interestingly, DMH-specific Prdm13-knockdown mice showed significantly reduced wake time during the dark period and decreased sleep quality, which was defined by the quantity of electroencephalogram delta activity during NREM sleep. DMH-specific Prdm13-knockdown mice also exhibited progressive increases in body weight and adiposity. Our findings indicate that Prdm13/Nkx2-1-mediated signaling in the DMC declines with advanced age, leading to decreased sleep quality and increased adiposity, which mimic age-associated pathophysiology, and provides a potential link to DMH-mediated aging and longevity control in mammals.
Transcriptional regulator PRDM12 is essential for human pain perception.
Chen Ya-Chun,Auer-Grumbach Michaela,Matsukawa Shinya,Zitzelsberger Manuela,Themistocleous Andreas C,Strom Tim M,Samara Chrysanthi,Moore Adrian W,Cho Lily Ting-Yin,Young Gareth T,Weiss Caecilia,Schabhüttl Maria,Stucka Rolf,Schmid Annina B,Parman Yesim,Graul-Neumann Luitgard,Heinritz Wolfram,Passarge Eberhard,Watson Rosemarie M,Hertz Jens Michael,Moog Ute,Baumgartner Manuela,Valente Enza Maria,Pereira Diego,Restrepo Carlos M,Katona Istvan,Dusl Marina,Stendel Claudia,Wieland Thomas,Stafford Fay,Reimann Frank,von Au Katja,Finke Christian,Willems Patrick J,Nahorski Michael S,Shaikh Samiha S,Carvalho Ofélia P,Nicholas Adeline K,Karbani Gulshan,McAleer Maeve A,Cilio Maria Roberta,McHugh John C,Murphy Sinead M,Irvine Alan D,Jensen Uffe Birk,Windhager Reinhard,Weis Joachim,Bergmann Carsten,Rautenstrauss Bernd,Baets Jonathan,De Jonghe Peter,Reilly Mary M,Kropatsch Regina,Kurth Ingo,Chrast Roman,Michiue Tatsuo,Bennett David L H,Woods C Geoffrey,Senderek Jan
Pain perception has evolved as a warning mechanism to alert organisms to tissue damage and dangerous environments. In humans, however, undesirable, excessive or chronic pain is a common and major societal burden for which available medical treatments are currently suboptimal. New therapeutic options have recently been derived from studies of individuals with congenital insensitivity to pain (CIP). Here we identified 10 different homozygous mutations in PRDM12 (encoding PRDI-BF1 and RIZ homology domain-containing protein 12) in subjects with CIP from 11 families. Prdm proteins are a family of epigenetic regulators that control neural specification and neurogenesis. We determined that Prdm12 is expressed in nociceptors and their progenitors and participates in the development of sensory neurons in Xenopus embryos. Moreover, CIP-associated mutants abrogate the histone-modifying potential associated with wild-type Prdm12. Prdm12 emerges as a key factor in the orchestration of sensory neurogenesis and may hold promise as a target for new pain therapeutics.
Genomic profile of a Li-Fraumeni-like syndrome patient with a 45,X/46,XX karyotype, presenting neither mutations in TP53 nor clinical stigmata of Turner syndrome.
Basso Tatiane R,Villacis Rolando A R,Canto Luisa M,Alves Vinicius M F,Lapa Rainer M L,Nóbrega Amanda F,Achatz Maria I,Rogatto Silvia R
Li-Fraumeni syndrome (LFS) is a hereditary disorder that predisposes patients to several types of cancer and is associated with TP53 germline mutations. Turner syndrome (TS) is one of the most common aneuploidies in women. Patients with TS have a higher risk of developing cancer, although multiple malignant tumors are extremely rare. Herein, we describe a patient with a 45,X/46,XX karyotype with no classic phenotype of TS. She presented with a clinical diagnosis of Li-Fraumeni-like syndrome (LFL), showing papillary thyroid carcinoma and fibrosarcoma of the left flank, and had no TP53 germline mutations. Genome-wide analysis of copy number variations (CNVs) was assessed in DNA from peripheral blood cells and saliva. A total of 109 rare CNVs in the blood cells, including mosaic loss of the X chromosome (76% of cells), were identified. In saliva, three rare CNVs were detected, all of them were also detected in the blood cells: loss of 8q24.11 (EXT1), gain of 16q24.3 (PRDM7 and GAS8), and the mosaic loss of the X chromosome (50% of cells). Results of conventional G-banding confirmed the 45,X/46,XX karyotype. Surprisingly, the patient presented with an apparently normal phenotype. The PRDM and GAS8 genes are potential candidates to be associated with the risk of developing cancer in this LFL/TS patient.
Characteristics of spermatogonial stem cells derived from neonatal porcine testis.
Shi R,Bai Y,Li S,Wei H,Zhang X,Li L,Tian X C,Jiang Q,Wang C,Qin L,Cai J,Zhang S
The aim of this study was to isolate and characterise porcine spermatogonial stem cells (PSSCs). The putative porcine germline stem cells from testis were isolated successfully by an improving way of enrichment with lymphocyte separation medium (LSM). Results from RT-PCR analyses showed that PSSCs were positive for OCT4, SOX2, NANOG, PGP9.5, c-MYC, KEL4 and PRDM-14 which are multipotent stem cell markers. At the protein level, the results of immunofluorescence analyses showed that PSSCs were positive for OCT4, PGP9.5, SOX2 and CD29. We successfully differentiated these PSSCs into adipocytes and muscle cells and then defined their characteristics, including morphology, surface stem cell markers, and mechanical properties. But the experiment of teratoma formation was negative. The results indicated the PSSCs could be multipotent. Atomic force microscopy was used to characterise the morphological and mechanical properties of undifferentiated PSSCs, as well as the differentiated adipocytes and muscle cells, which could be potentially useful for distinguishing PSSCs from differentiated cells.
Different isoforms of BSAP regulate expression of AID in normal and chronic lymphocytic leukemia B cells.
Oppezzo Pablo,Dumas Gérard,Lalanne Ana Inés,Payelle-Brogard Béatrice,Magnac Christian,Pritsch Otto,Dighiero Guillaume,Vuillier Françoise
Activation-induced cytidine deaminase (AID) is key to initiating somatic hypermutation (SHM) and class switch recombination (CSR), but its mode of action and regulation remains unclear. Since Pax-5 and Id-2 transcription factors play an opposing role in AID regulation, we have studied the expression of Pax-5, Id-2, and prdm-1 genes in 54 chronic lymphocytic leukemia (CLL) B cells. In 21 cases, presence of AID is constantly associated with high expression of the complete form of the Pax-5 gene (Pax-5a) and lower expression of the Id-2 and prdm-1 transcripts. In 33 cases, the absence of AID expression and CSR is associated with a reduction of Pax-5a and the appearance of a spliced form with a deletion in exon 8 (Pax-5/Delta-Ex8). Stimulation with CD40L+interleukin 4 (IL-4) induces CSR, the presence of AID transcripts, up-regulation of Pax-5a and down-regulation of Pax-5/Delta-Ex8, and Id-2 and prdm-1 transcripts. Pax-5a and Pax-5/Delta-Ex8 are translated into 2 isoforms of the B-cell-specific activator protein (BSAP) and both are able to bind the AID-promoter region. Overall, these results suggest that Pax-5/Delta-Ex8 could play an important role in the control of its own transcription and indirectly in AID expression and CSR.
Homeobox-clock protein interaction in zebrafish. A shared mechanism for pineal-specific and circadian gene expression.
Appelbaum Lior,Anzulovich Ana,Baler Ruben,Gothilf Yoav
The Journal of biological chemistry
In non-mammalian vertebrates, the pineal gland is photoreceptive and contains an intrinsic circadian oscillator that drives rhythmic production and secretion of melatonin. These features require an accurate spatiotemporal expression of an array of specific genes in the pineal gland. Among these is the arylalkylamine N-acetyltransferase, a key enzyme in the melatonin production pathway. In zebrafish, pineal specificity of zfaanat2 is determined by a region designated the pineal-restrictive downstream module (PRDM), which contains three photoreceptor conserved elements (PCEs) and an E-box, elements that are generally associated with photoreceptor-specific and rhythmic expression, respectively. Here, by using in vivo and in vitro approaches, it was found that the PCEs and E-box of the PRDM mediate a synergistic effect of the photoreceptor-specific homeobox OTX5 and rhythmically expressed clock protein heterodimer, BMAL/CLOCK, on zfaanat2 expression. Furthermore, the distance between the PCEs and the E-box was found to be critical for PRDM function, suggesting a possible physical feature of this synergistic interaction. OTX5-BMAL/CLOCK may act through this mechanism to simultaneously control pineal-specific and rhythmic expression of zfaanat2 and possibly also other pineal and retinal genes.
[Research Progress of PR Domain Zinc Finger Protein 14].
Han Yudong,Lin Qiang
Zhongguo fei ai za zhi = Chinese journal of lung cancer
PR domain zinc finger protein 14 (PRDM14) is an important member of the PRDM family, PRDM14 plays a key role in the maintenance of cell integrity and differentiation, growth and apoptosis of the cell. It also plays an critical role in the formation of primordial germ cells, the maintenance of the totipotency of stem cells and the formation of tissues and organs. PRDM14 bears a single PR domain and six tandemly repeated zinc ﬁngers, which is involved in the process of the deacetylation and methylation of the histone, and is involved in the formation of tumor trough the change level of methylation in the promoter region. The abnormal methylation of PRDM14 can change the chromatin structure, DNA conformation and the interaction mode of DNA and protein, it can suppress transcription and expression of the gene, which caused the occurrence, development and metastasis of tumor. The research progress of PRDM14 is reviewed based on the relevant literatures published in China and abroad.
Upregulation of PRDM5 Is Associated with Astrocyte Proliferation and Neuronal Apoptosis Caused by Lipopolysaccharide.
Zhang Yu,Liu Xiaojuan,Xue Huaqing,Liu Xiaorong,Dai Aihua,Song Yan,Ke Kaifu,Cao Maohong
Journal of molecular neuroscience : MN
PRDM5 (PR domain containing 5) belongs to PRDM family which consists of transcriptional regulators that modulate cellular processes such as cell growth, differentiation and apoptosis. However, the function of PRDM5 in central nervous system (CNS) inflammatory response is unknown. In recent study, an adult rat neuroinflammation model via lipopolysaccharide (LPS) lateral ventricle injection was constructed. PRDM5 expression was increased in activated astrocytes and apoptotic neurons of the adult rat cerebral cortex after LPS injection. In vitro studies showed that the remarkable upregulation of PRDM5 might be involved in rat primary astrocyte proliferation and rat primary neuronal apoptosis in the cerebral cortex following LPS administration. In addition, using PRDM5 RNA interference both in rat primary asrtocytes and neurons, further indicated that PRDM5 was required for astrocyte proliferation and neuronal apoptosis induced by LPS. Our findings on the cellular signaling pathway may provide a new therapeutic strategy against neuroinflammation in the CNS.
Brown adipose tissue: Updates in cellular and molecular biology.
Bargut Thereza Cristina Lonzetti,Aguila Marcia Barbosa,Mandarim-de-Lacerda Carlos Alberto
Tissue & cell
Brown adipose tissue (BAT) is mainly composed of adipocytes, it is highly vascularized and innervated, and can be activated in adult humans. Brown adipocytes are responsible for performing non-shivering thermogenesis, which is exclusively mediated by uncoupling protein (UCP) -1 (a protein found in the inner mitochondrial membrane), the hallmark of BAT, responsible for the uncoupling of the proton leakage from the ATP production, therefore, generating heat (i.e. thermogenesis). Besides UCP1, other compounds are essential not only to thermogenesis, but also to the proliferation and differentiation of BAT, including peroxisome proliferator-activated receptor (PPAR) family, PPARgamma coactivator 1 (PGC1)-alpha, and PRD1-BF-1-RIZ1 homologous domain protein containing protein (PRDM) -16. The sympathetic nervous system centrally regulates thermogenesis through norepinephrine, which acts on the adrenergic receptors of BAT. This bound leads to the initialization of the many pathways that may activate thermogenesis in acute and/or chronic ways. In summary, this mini-review aims to demonstrate the latest advances in the knowledge of BAT.
Whole-exome sequencing identifies variants in invasive pituitary adenomas.
Lan Xiaolei,Gao Hua,Wang Fei,Feng Jie,Bai Jiwei,Zhao Peng,Cao Lei,Gui Songbai,Gong Lei,Zhang Yazhuo
Pituitary adenomas exhibit a wide range of behaviors. The prediction of invasion or malignant behavior in pituitary adenomas remains challenging. The objective of the present study was to identify the genetic abnormalities associated with invasion in sporadic pituitary adenomas. In the present study, the exomes of six invasive pituitary adenomas (IPA) and six non-invasive pituitary adenomas (nIPA) were sequenced by whole-exome sequencing. Variants were confirmed by dideoxynucleotide sequencing, and candidate driver genes were assessed in an additional 28 pituitary adenomas. A total of 15 identified variants were mainly associated with angiogenesis, metabolism, cell cycle phase, cellular component organization, cytoskeleton and biogenesis immune at a cellular level, including 13 variants that occurred as single nucleotide variants and 2 that comprised of insertions. The messenger RNA (mRNA) levels of diffuse panbronchiolitis critical region 1 (DPCR1), KIAA0226, myxovirus (influenza virus) resistance, proline-rich protein BstNI subfamily 3, PR domain containing 2, with ZNF domain, RIZ1 (PRDM2), PR domain containing 8 (PRDM8), SPANX family member N2 (SPANXN2), TRIO and F-actin binding protein and zinc finger protein 717 in IPA specimens were 50% decreased compared with nIPA specimens. In particular, DPCR1, PRDM2, PRDM8 and SPANXN2 mRNA levels in IPA specimens were approximately four-fold lower compared with nIPA specimens (P=0.003, 0.007, 0.009 and 0.004, respectively). By contrast, the mRNA levels of dentin sialophospho protein, EGF like domain, multiple 7 (EGFL7), low density lipoprotein receptor-related protein 1B and dynein, axonemal, assembly factor 1 (LRRC50) were increased in IPA compared with nIPA specimens (P=0.041, 0.037, 0.022 and 0.013, respectively). Furthermore, decreased PRDM2 expression was associated with tumor recurrence. The findings of the present study indicate that DPCR1, EGFL7, the PRDM family and LRRC50 in pituitary adenomas are modifiers of tumorigenesis, and most likely contribute to the development of oncocytic change and to the invasive tumor phenotype.
PRDM5 Expression and Essential Role After Acute Spinal Cord Injury in Adult Rat.
Liu Jie,Wu Weijie,Hao Jie,Yu Mingchen,Liu Jin,Chen Xinlei,Qian Rong,Zhang Feng
PR (PRDI-BF1 and RIZ) domain proteins (PRDM) are a subfamily of the kruppel-like zinc finger gene products that modulate cellular processes such as differentiation, cell growth and apoptosis. PRDM5 is a recently identified family member that functions as a transcriptional repressor and behaves as a putative tumor suppressor in different types of cancer. However, the expression and function of PRDM5 in spinal cord injury (SCI) are still unknown. In the present study, we have performed an acute SCI model in adult rats and investigated the dynamic changes of PRDM5 expression in the spinal cord. We found that PRDM5 protein levels gradually increased, reaching a peak at day 5 and then gradually declined to a normal level at day 14 after SCI with Western blot analysis. Double immunofluorescence staining showed that PRDM5 immunoreactivity was found in neurons, astrocytes and microglia. However, the expression of PRDM5 was increased predominantly in neurons. Additionally, colocalization of PRDM5/active caspase-3 was been respectively detected in neurons. In vitro, we found that depletion of PRDM5 by short interfering RNA, obviously decreases neuronal apoptosis. In summary, this is the first description of PRDM5 expression in SCI. Our results suggested that PRDM5 might play crucial roles in CNS pathophysiology after SCI and this research will provide new drug targets for clinical treatment of SCI.
Is famine exposure during developmental life in rural Bangladesh associated with a metabolic and epigenetic signature in young adulthood? A historical cohort study.
Finer S,Iqbal M S,Lowe R,Ogunkolade B W,Pervin S,Mathews C,Smart M,Alam D S,Hitman G A
OBJECTIVES:Famine exposure in utero can 'programme' an individual towards type 2 diabetes and obesity in later life. We sought to identify, (1) whether Bangladeshis exposed to famine during developmental life are programmed towards diabetes and obesity, (2) whether this programming was specific to gestational or postnatal exposure windows and (3) whether epigenetic differences were associated with famine exposure. DESIGN:A historical cohort study was performed as part of a wider cross-sectional survey. Exposure to famine was defined through birth date and historical records and participants were selected according to: (A) exposure to famine in postnatal life, (B) exposure to famine during gestation and (C) unexposed. SETTING:Matlab, a rural area in the Chittagong division of Bangladesh. PARTICIPANTS:Young adult men and women (n=190) recruited to a historical cohort study with a randomised subsample included in an epigenetic study (n=143). OUTCOME MEASURES:Primary outcome measures of weight, body mass index and oral glucose tolerance tests (0 and 120 min glucose). Secondary outcome measures included DNA methylation using genome-wide and targeted analysis of metastable epialleles sensitive to maternal nutrition. RESULTS:More young adults exposed to famine in gestation were underweight than those postnatally exposed or unexposed. In contrast, more young adults exposed to famine postnatally were overweight compared to those gestationally exposed or unexposed. Underweight adults exposed to famine in gestation in utero were hyperglycaemic following a glucose tolerance test, and those exposed postnatally had elevated fasting glucose, compared to those unexposed. Significant differences in DNA methylation at seven metastable epialleles (VTRNA2-1, PAX8, PRDM-9, near ZFP57, near BOLA, EXD3) known to vary with gestational famine exposure were identified. CONCLUSIONS:Famine exposure in developmental life programmed Bangladeshi offspring towards diabetes and obesity in adulthood but gestational and postnatal windows of exposure had variable effects on phenotype. DNA methylation differences were replicated at previously identified metastable epialleles sensitive to periconceptual famine exposure.
[Relationship between the expression of PRDM14 in non-small cell lung cancer and the clinicopathologic characteristics].
Liu Bingbing,Zhang Siyang,Hui Linping,Qiu Xueshan,Cui Zeshi
Zhongguo fei ai za zhi = Chinese journal of lung cancer
BACKGROUND AND OBJECTIVE:The positive regulatory domain proteins (PRDM) are family of transcriptional regulation related to the formation of human tumor factor and play key roles in the cell differentiation and malignant transformation. PRDM14 is a member of the PRDM family. The aim of this study is to detect the expression of PRDM14 in non-small cell lung cancer (NSCLC) tissues, and analyze its relationship with clinicopathologic characteristics of NSCLC. METHODS:PRDM14 expression was detected in 70 NSCLC specimens and 7 paracancerous tissues using the immunohistochemistry (SP method). The PRDM14 protein expression was determined in 42 NSCLC specimens and 42 paracancerous tissues by Western blot. RESULTS:Among 70 NSCLC specimens, 8 specimens showed weak expression of PRDM14 (11.43%, 8/70), 62 specimens showed moderate to strong staining of PRDM14 (88.57%, 62/70), whereas 7 paracancerous specimens showed weak staining extent. PRDM14 expression level was positively correlated with differentiation (P=0.046) and histological type (P=0.047). The positive cytoplasmic expression of PRDM14 in highly differentiated NSCLC, the low expression of PRDM14 in poorly differentiated NSCLC. The results of Western blot showed that there were significant difference between the two groups (P<0.001); expression of PRDM14 was conspicuous in NSCLC specimens but low in paracancerous tissues. PRDM14 expression level was positively correlated with differentiation (P=0.017). The positive cytoplasmic expression of PRDM14 in highly differentiated NSCLC, the low expression of PRDM14 in poorly differentiated NSCLC. CONCLUSIONS:The high expression of PRDM14 in NSCLC is associated with differentiation and histological type. The PRDM14 may play an important role in the development of NSCLC.
Discovery and characterisation of the automethylation properties of PRDM9.
Koh-Stenta Xiaoying,Poulsen Anders,Li Rong,Wee John Liang Kuan,Kwek Perlyn Zekui,Chew Sin Yin,Peng Jianhe,Wu Liling,Guccione Ernesto,Joy Joma,Hill Jeffrey
The Biochemical journal
We have previously characterised the histone lysine methyltransferase properties of PRDM9, a member of the PRDM family of putative transcriptional regulators. PRDM9 displays broad substrate recognition and methylates a range of histone substrates, including octamers, core histone proteins, and peptides. In the present study, we show that PRDM9 performs intramolecular automethylation on multiple lysine residues localised to a lysine-rich region on the post-SET (suppressor of variegation 3-9, enhancer of zeste and trithorax) domain. PRDM9 automethylation is abolished by a single active-site mutation, C321P, also known to disrupt interactions with -adenosylmethionine. We have taken an initial step towards tool compound generation through rational design of a substrate-mimic, peptidic inhibitor of PRDM9 automethylation. The discovery of automethylation in PRDM9 adds a new dimension to our understanding of PRDM9 enzymology.
The epigenetic modifier PRDM5 functions as a tumor suppressor through modulating WNT/β-catenin signaling and is frequently silenced in multiple tumors.
Shu Xing-sheng,Geng Hua,Li Lili,Ying Jianming,Ma Chunhong,Wang Yajun,Poon Fan Fong,Wang Xian,Ying Ying,Yeo Winnie,Srivastava Gopesh,Tsao Sai Wah,Yu Jun,Sung Joseph J Y,Huang Shi,Chan Anthony T C,Tao Qian
BACKGROUND:PRDM (PRDI-BF1 and RIZ domain containing) proteins are zinc finger proteins involved in multiple cellular regulations by acting as epigenetic modifiers. We studied a recently identified PRDM member PRDM5 for its epigenetic abnormality and tumor suppressive functions in multiple tumorigeneses. METHODOLOGY/PRINCIPAL FINDINGS:Semi-quantitative RT-PCR showed that PRDM5 was broadly expressed in human normal tissues, but frequently silenced or downregulated in multiple carcinoma cell lines due to promoter CpG methylation, including 80% (4/5) nasopharyngeal, 44% (8/18) esophageal, 76% (13/17) gastric, 50% (2/4) cervical, and 25% (3/12) hepatocellular carcinoma cell lines, but not in any immortalized normal epithelial cell lines. PRDM5 expression could be restored by 5-aza-2'-deoxycytidine demethylation treatment in silenced cell lines. PRDM5 methylation was frequently detected by methylation-specific PCR (MSP) in multiple primary tumors, including 93% (43/46) nasopharyngeal, 58% (25/43) esophageal, 88% (37/42) gastric and 63% (29/46) hepatocellular tumors. PRDM5 was further found a stress-responsive gene, but its response was impaired when the promoter was methylated. Ectopic PRDM5 expression significantly inhibited tumor cell clonogenicity, accompanied by the inhibition of TCF/β-catenin-dependent transcription and downregulation of CDK4, TWIST1 and MDM2 oncogenes, while knocking down of PRDM5 expression lead to increased cell proliferation. ChIP assay showed that PRDM5 bound to its target gene promoters and suppressed their transcription. An inverse correlation between the expression of PRDM5 and activated β-catenin was also observed in cell lines. CONCLUSIONS/SIGNIFICANCE:PRDM5 functions as a tumor suppressor at least partially through antagonizing aberrant WNT/β-catenin signaling and oncogene expression. Frequent epigenetic silencing of PRDM5 is involved in multiple tumorigeneses, which could serve as a tumor biomarker.
PRDM5 promotes the apoptosis of epithelial cells induced by IFN-γ during Crohn's disease.
Wu Han,Wang Liang,Zhang Dongmei,Qian Ji,Yan Lijun,Tang Qiyun,Ni Runzhou,Zou Xiaoping
Pathology, research and practice
Elevated apoptosis of intestinal epithelial cells (IECs) greatly impairs the epithelial barrier integrity and contributes to the pathogenesis of Crohn's Disease (CD). Overproduction of pro-inflammatory cytokine Interferon-γ (IFN-γ) induces the excessive apoptosis of IECs and is involved in CD development. PRDM5 (PR domain containing 5 PFM2) a member of PRDM family, reportedly acts as a transcriptional regulator involved in tissue specific differentiation and tumor development. In this study, we investigated PRDM5 expression and its potential functions in both human CD (Crohn's disease) and TNBS (2,4,6-trinitrobenzenesulfonic acid sol)-induced mice experimental colitis. As shown by western blot and immunohistochemistry, significant up-regulation of PRDM5 was found in the inflamed intestinal tissues of CD patients and TNBS-treated mice, and the molecule was mainly located in IECs. To explore the biological functions of PRDM5 in IEC apoptosis, we established the interferon-γ (IFN-γ) induced cellular apoptosis model on human IEC line HT29 in vitro. IFN-γ significantly increased the expression of PRDM5 in a both time-dependent and concentration-dependent manner in HT29 cells, which was accompanied with an up-regulated expression of apoptotic markers (active caspase-3 and cleaved PARP(poly (ADP-ribpse) polymerase)). Inhibiting PRDM5 expression by siRNA attenuated the IFN-γ-triggered accumulation of active caspase-3 and cleaved PARP in IECs. Moreover, flow cytometry assay and CCK-8 analysis revealed that PRDM5 knockdown significantly alleviated the IFN-γ-induced cellular apoptosis in HT29 cells. Taken together, these data suggest that highly expressed PRDM5 may promote the IFN-γ-induced IEC apoptosis in the progression of CD.
Green tea extract induces genes related to browning of white adipose tissue and limits weight-gain in high energy diet-fed rat.
Chen Li-Han,Chien Yi-Wen,Liang Chung-Tiang,Chan Ching-Hung,Fan Meng-Han,Huang Hui-Yu
Food & nutrition research
A wealth of research has reported on the anti-obesity effects of green tea extract (GTE). Although browning of white adipose tissue (WAT) has been reported to attenuate obesity, no study has disclosed the effects of GTE on browning in Sprague Dawley rats. The aims of the study were to investigate the effects of GTE on anti-obesity and browning, and their underlying mechanisms. Four groups of rats (n=10/group) were used including a normal diet with vehicle treatment, and a high-energy diet (HED) with vehicle or GTE by oral gavage at 77.5 or 155 mg/kg/day for 8 weeks. Body weight, fat accumulation, and serum biochemical parameters were used to evaluate obesity. The gene expressions were analyzed using RT-qPCR and western blotting. GTE modulated HED-induced body weight, fat accumulation, and serum levels of triacylglycerol, total cholesterol, low-density lipoprotein, free fatty acids, aspartate aminotransferase, and alanine aminotransferase. Moreover, GTE enhanced the serum high-density lipoprotein. Most importantly, the biomarkers of beige adipose tissue were up-regulated in WAT in GTE-given groups. GTE induced genes involved in different pathways of browning, and reduced transducin-like enhancer protein-3 in WAT. Our results suggest that GTE may improve obesity through inducing browning in HED-fed rats. : ALT: Alanine transaminase; AST: Aspartate transaminase; BAT: Brown adipose tissue; BMP-7: Bone morphogenetic protein-7; BW: Body weight; CIDEA: Cell death activator; CPT-1: Carnitine palmitoyltransferase-1; EFP: Epididymal fat pad; FFA: Free fatty acid; FGF-21: Fibroblast growth factor-21; GTE: Green tea extract; HDL: High-density lipoprotein; HED: high-energy diet; LDL: Low-density lipoprotein; MFP: Mesenteric fat pad; PGC-1α: Activates PPAR-γ coactivator-1; PPAR-γ: Peroxisome proliferator-activated receptor-γ; PRDM-16: PR domain containing 16; RFP: Renal fat pad; SD: Sprague Dawley; TC: Total cholesterol; TG: Triacylglycerol; TLE-3: Transducin-like enhancer protein-3: UCP-1: Uncoupling protein-1; WAT: White adipose tissue.
Blimp-1-dependent and -independent natural antibody production by B-1 and B-1-derived plasma cells.
Savage Hannah P,Yenson Vanessa M,Sawhney Sanjam S,Mousseau Betty J,Lund Frances E,Baumgarth Nicole
The Journal of experimental medicine
Natural antibodies contribute to tissue homeostasis and protect against infections. They are secreted constitutively without external antigenic stimulation. The differentiation state and regulatory pathways that enable continuous natural antibody production by B-1 cells, the main cellular source in mice, remain incompletely understood. Here we demonstrate that natural IgM-secreting B-1 cells in the spleen and bone marrow are heterogeneous, consisting of (a) terminally differentiated B-1-derived plasma cells expressing the transcriptional regulator of differentiation, Blimp-1, (b) Blimp-1, and (c) Blimp-1 phenotypic B-1 cells. Blimp-1 IgM-secreting B-1 cells are not simply intermediates of cellular differentiation. Instead, they secrete similar amounts of IgM in wild-type and Blimp-1-deficient (PRDM-1) mice. Blimp-1 B-1 cells are also a major source of IgG3. Consequently, deletion of Blimp-1 changes neither serum IgG3 levels nor the amount of IgG3 secreted per cell. Thus, the pool of natural antibody-secreting B-1 cells is heterogeneous and contains a distinct subset of cells that do not use Blimp-1 for initiation or maximal antibody secretion.
The PRDM9 KRAB domain is required for meiosis and involved in protein interactions.
Imai Yukiko,Baudat Frédéric,Taillepierre Miguel,Stanzione Marcello,Toth Attila,de Massy Bernard
PR domain-containing protein 9 (PRDM9) is a major regulator of the localization of meiotic recombination hotspots in the human and mouse genomes. This role involves its DNA-binding domain, which is composed of a tandem array of zinc fingers, and PRDM9-dependent trimethylation of histone H3 at lysine 4. PRDM9 is a member of the PRDM family of transcription regulators, but unlike other family members, it contains a Krüppel-associated box (KRAB)-related domain that is predicted to be a potential protein interaction domain. Here, we show that truncation of the KRAB domain of mouse PRDM9 leads to loss of PRDM9 function and altered meiotic prophase and gametogenesis. In addition, we identified proteins that interact with the KRAB domain of PRDM9 in yeast two-hybrid assay screens, particularly CXXC1, a member of the COMPASS complex. We also show that CXXC1 interacts with IHO1, an essential component of the meiotic double-strand break (DSB) machinery. As CXXC1 is orthologous to Saccharomyces cerevisiae Spp1 that links DSB sites to the DSB machinery on the chromosome axis, we propose that these molecular interactions involved in the regulation of meiotic DSB formation are conserved in mouse meiosis.
Oxidative stress-induced S100B accumulation converts myoblasts into brown adipocytes via an NF-κB/YY1/miR-133 axis and NF-κB/YY1/BMP-7 axis.
Morozzi Giulio,Beccafico Sara,Bianchi Roberta,Riuzzi Francesca,Bellezza Ilaria,Giambanco Ileana,Arcuri Cataldo,Minelli Alba,Donato Rosario
Cell death and differentiation
Muscles of sarcopenic people show hypotrophic myofibers and infiltration with adipose and, at later stages, fibrotic tissue. The origin of infiltrating adipocytes resides in fibro-adipogenic precursors and nonmyogenic mesenchymal progenitor cells, and in satellite cells, the adult stem cells of skeletal muscles. Myoblasts and brown adipocytes share a common Myf5 progenitor cell: the cell fate depends on levels of bone morphogenetic protein 7 (BMP-7), a TGF-β family member. S100B, a Ca-binding protein of the EF-hand type, is expressed at relatively high levels in myoblasts from sarcopenic humans and exerts anti-myogenic effects via NF-κB-dependent inhibition of MyoD, a myogenic transcription factor acting upstream of the essential myogenic factor, myogenin. Adipogenesis requires high levels of ROS, and myoblasts of sarcopenic subjects show elevated ROS levels. Here we show that: (1) ROS overproduction in myoblasts results in upregulation of S100B levels via NF-κB activation; and (2) ROS/NF-κB-induced accumulation of S100B causes myoblast transition into brown adipocytes. S100B activates an NF-κB/Ying Yang 1 axis that negatively regulates the promyogenic and anti-adipogenic miR-133 with resultant accumulation of the brown adipogenic transcription regulator, PRDM-16. S100B also upregulates BMP-7 via NF-κB/Ying Yang 1 with resultant BMP-7 autocrine activity. Interestingly, myoblasts from sarcopenic humans show features of brown adipocytes. We also show that S100B levels and NF-κB activity are elevated in brown adipocytes obtained by culturing myoblasts in adipocyte differentiation medium and that S100B knockdown or NF-κB inhibition in myoblast-derived brown adipocytes reconverts them into fusion-competent myoblasts. At last, interstitial cells and, unexpectedly, a subpopulation of myofibers in muscles of geriatric but not young mice co-express S100B and the brown adipocyte marker, uncoupling protein-1. These results suggest that S100B is an important intracellular molecular signal regulating Myf5 progenitor cell differentiation into fusion-competent myoblasts or brown adipocytes depending on its levels.
Genome-wide association study identifies novel susceptibility loci for migraine in Han Chinese resided in Taiwan.
Chen Shih-Pin,Fuh Jong-Ling,Chung Ming-Yi,Lin Ying-Chao,Liao Yi-Chu,Wang Yen-Feng,Hsu Chia-Lin,Yang Ueng-Cheng,Lin Ming-Wei,Chiou Jen-Jie,Wang Po-Jen,Chen Ping-Kun,Fan Pi-Chuan,Wu Jer-Yuan,Chen Yuan-Tsong,Kao Lung-Sen,Shen-Jang Fann Cathy,Wang Shuu-Jiun
Cephalalgia : an international journal of headache
Background Susceptibility genes for migraine, despite it being a highly prevalent and disabling neurological disorder, have not been analyzed in Asians by genome-wide association study (GWAS). Methods We conducted a two-stage case-control GWAS to identify susceptibility genes for migraine without aura in Han Chinese residing in Taiwan. In the discovery stage, we genotyped 1005 clinic-based Taiwanese migraine patients and 1053 population-based sex-matched controls using Axiom Genome-Wide CHB Array. In the replication stage, we genotyped 27 single-nucleotide polymorphisms with p < 10 in 1120 clinic-based migraine patients and 604 sex-matched normal controls by using Sequenom. Variants at LRP1, TRPM8, and PRDM, which have been replicated in Caucasians, were also genotyped. Results We identified a novel susceptibility locus (rs655484 in DLG2) that reached GWAS significance level for migraine risk in Han Chinese ( p = 1.45 × 10, odds ratio [OR] = 2.42), and also another locus (rs3781545in GFRA1) with suggestive significance ( p = 1.27 × 10, OR = 1.38). In addition, we observed positive association signals with a similar trend to the associations identified in Caucasian GWASs for rs10166942 in TRPM8 (OR = 1.33, 95% confidence interval [CI] = 1.14-1.54, P = 9.99 × 10; risk allele: T) and rs1172113 in LRP1 (OR = 1.23, 95% CI = 1.04-1.45, P = 2.9 × 10; risk allele: T). Conclusion The present study is the first migraine GWAS conducted in Han-Chinese and Asians. The newly identified susceptibility genes have potential implications in migraine pathogenesis. DLG2 is involved in glutamatergic neurotransmission, and GFRA1 encodes GDNF receptors that are abundant in CGRP-containing trigeminal neurons. Furthermore, positive association signals for TRPM8 and LRP1 suggest the possibility for common genetic contributions across ethnicities.
PRDM14, a putative histone methyl-transferase, interacts with and decreases the stability and activity of the HOXA1 transcription factor.
Draime Amandine,Bridoux Laure,Belpaire Magali,Pringels Tamara,Tys Janne,Rezsohazy René
Biochimica et biophysica acta. Gene regulatory mechanisms
Understanding how the activity of transcription factors like HOX proteins is regulated remains a widely open question. In a recent screen for proteins interacting with HOXA1, we identified a PRDM protein family member, PRDM14, which is known to be transiently co-expressed with HOXA1 in epiblast cells before their specification towards somatic versus germ cell fate. Here, we confirm PRDM14 is an interactor of HOXA1 and we identify the homeodomain of HOXA1 as well as the PR domain and Zinc fingers of PRDM14 to be required for the interaction. An 11-His repeat of HOXA1 previously highlighted to contribute to HOXA1-mediated protein-protein interactions is also involved. At a functional level, we provide evidence that HOXA1 displays an unexpectedly long half-life and demonstrate that PRDM14 can reduce the stability and affect the transcriptional activity of HOXA1.
Effects of PRDM14 Silencing on Parthenogenetically Activated Porcine Embryos.
Cheng Hui,Wang Yutian,Zhang Jian,Zhang Sheng,Ma Xiaoling,An Xinglan,Man Xiaxia,Zhang Xueming,Li Ziyi,Tang Bo
PRDM14, a member of the PRDM family protein, plays an important role in the regulation of epigenetic reprogramming. Knockdown of in germ cells can lead to female and male subfertility, and the function of PRDM14 appears to be conserved across mammalian species. Thus, we analyzed the expression of in parthenogenetic embryos at all stages of preimplantation and then evaluated the effect of downregulation on porcine parthenogenetic embryonic development. We found that transcripts are highly expressed in the metaphase II (MII) oocyte, and their level gradually increased from the 2-cell to 8-cell stage and slightly declined at the blastocyst stage during the development of parthenogenetic porcine embryos. was knocked down in oocytes at the MII stage by the injection of siRNA to assess the role of this protein in epigenetic remodeling and embryo development. knockdown significantly decreased the cleavage and blastocyst rates without changing the total cell number of the blastocysts. In addition, the expression levels of the antiapoptotic gene and the pluripotency-related genes and were also significantly decreased. These results showed that PRDM14 could affect embryonic development through regulating the expression levels of the pluripotency and antiapoptotic genes during the development of parthenogenetically activated porcine embryos.
Pretransplant metabolic syndrome and its components predict post-transplantation diabetes mellitus in Chinese patients receiving a first renal transplant.
Cai Ruiming,Wu Meng,Xing Yanfang
Therapeutics and clinical risk management
BACKGROUND:Post-transplantation diabetes mellitus (PTDM) remains a major clinical challenge following renal transplant. Identification of pretransplant modifiable risk factors may allow timely interventions to prevent PTDM. This study aims to determine whether pretransplant metabolic syndrome and its components are able to predict PTDM in Chinese patients receiving their first renal transplant. PATIENTS AND METHODS:We conducted a single-center retrospective study of 633 non-diabetic patients receiving a first kidney transplant. PTDM was diagnosed between 1 month and 1 year post-transplant. Multivariable logistic regression and Cox proportional hazards model were applied to detect potential pretransplant risk factors for PTDM. RESULTS:One year post-transplant, 26.2% of recipients had developed PTDM. PTDM patients had significantly higher fasting plasma glucose (FPG) (=0.026) and body mass index (BMI) (=0.006) than non-PRDM patients, and lower levels of high-density lipoprotein cholesterol (=0.015). The presence of metabolic syndrome was an independent risk factor for PTDM, as assessed by multivariable logistic regression analysis (OR 1.28, 95% CI 1.04-1.51, =0.038) and Cox proportional hazards model (OR 2.75, 95% CI 1.45-6.05, =0.021). Moreover, both FPG >5.6 mmol/L and BMI >28 kg/m (obesity) were able to predict PTDM. CONCLUSION:Our results suggest that the presence of metabolic syndrome and its components, impaired fasting glycemia and obesity, are independent risk factors for PTDM in Chinese non-diabetic patients receiving a first renal transplant. Interventions aimed at improving pretransplant metabolic syndrome may reduce the incidence of PTDM.
The Prdm13 histone methyltransferase encoding gene is a Ptf1a-Rbpj downstream target that suppresses glutamatergic and promotes GABAergic neuronal fate in the dorsal neural tube.
Hanotel Julie,Bessodes Nathalie,Thélie Aurore,Hedderich Marie,Parain Karine,Van Driessche Benoit,Brandão Karina De Oliveira,Kricha Sadia,Jorgensen Mette C,Grapin-Botton Anne,Serup Palle,Van Lint Carine,Perron Muriel,Pieler Tomas,Henningfeld Kristine A,Bellefroid Eric J
The basic helix-loop-helix (bHLH) transcriptional activator Ptf1a determines inhibitory GABAergic over excitatory glutamatergic neuronal cell fate in progenitors of the vertebrate dorsal spinal cord, cerebellum and retina. In an in situ hybridization expression survey of PR domain containing genes encoding putative chromatin-remodeling zinc finger transcription factors in Xenopus embryos, we identified Prdm13 as a histone methyltransferase belonging to the Ptf1a synexpression group. Gain and loss of Ptf1a function analyses in both frog and mice indicates that Prdm13 is positively regulated by Ptf1a and likely constitutes a direct transcriptional target. We also showed that this regulation requires the formation of the Ptf1a-Rbp-j complex. Prdm13 knockdown in Xenopus embryos and in Ptf1a overexpressing ectodermal explants lead to an upregulation of Tlx3/Hox11L2, which specifies a glutamatergic lineage and a reduction of the GABAergic neuronal marker Pax2. It also leads to an upregulation of Prdm13 transcription, suggesting an autonegative regulation. Conversely, in animal caps, Prdm13 blocks the ability of the bHLH factor Neurog2 to activate Tlx3. Additional gain of function experiments in the chick neural tube confirm that Prdm13 suppresses Tlx3(+)/glutamatergic and induces Pax2(+)/GABAergic neuronal fate. Thus, Prdm13 is a novel crucial component of the Ptf1a regulatory pathway that, by modulating the transcriptional activity of bHLH factors such as Neurog2, controls the balance between GABAergic and glutamatergic neuronal fate in the dorsal and caudal part of the vertebrate neural tube.
Methylation of PRDM2, PRDM5 and PRDM16 genes in lung cancer cells.
Tan Shuang-Xiang,Hu Rui-Cheng,Liu Jing-Jing,Tan Yong-Li,Liu Wen-En
International journal of clinical and experimental pathology
AIMS:To investigate the changes of expression and methylation status of PRDM2, PRDM5, PRDM16 in lung cancer cells after treatment with demethylation agent. METHODS:A549 (lung adenocarcinoma cell line), HTB-182 (lung squamous cell carcinoma cell line) and HBE (normal bronchial cell line) were treated with 5-aza-2dC. The methylation state of PRDM2, PRDM5, PRDM16 was detected by MSP. The expression of PRDM2, PRDM5, PRDM16 was detected by RT-PCR and Western blot analysis. Cell growth was detected by MTT assay. RESULTS:5-aza-2-dC reduced the methylation of PRDM2, PRDM5, PRDM16 gene in A549 and HTB-182 cells but not in HBE cells. Consistently, 5-aza-2dC increased mRNA and protein expression of PRDM2, PRDM5, PRDM16 in A549 and HTB-182 cells but not in HBE cells. Furthermore, 5-aza-2dC inhibited the growth of A549 and HTB-182 cells but not HBE cells. CONCLUSIONS:PRDM2, PRDM5, PRDM16 promoters are methylated and their expression is suppressed in lung cancer cells. Demethylation drug 5-aza-2dC could upregulate the expression of PRDM2, PRDM5, PRDM16 and suppress lung cancer cell growth. 5-aza-2dC has potential to be used for lung cancer therapy by epigenetic mechanism.
JAK3/STAT3 oncogenic pathway and PRDM1 expression stratify clinicopathologic features of extranodal NK/T‑cell lymphoma, nasal type.
Liu Jumei,Liang Li,Li Dong,Nong Lin,Zheng Yalin,Huang Sixia,Zhang Bo,Li Ting
The inactivation of tumor suppressor gene positive regulatory domain containing I (PRDM1) and activation of signal transducer and activator of transcription 3 (STAT3) have been detected in the majority of extranodal NK/T‑cell lymphoma, nasal type (EN‑NK/T‑NT) cases. In the present study, their association with and effects on the clinicopathologic features of EN‑NK/T‑NT are described. PRDM1 was revealed to be expressed in 19 out of 58 patients (32.8%) with EN‑NK/T‑NT, and phosphorylated STAT3 was overexpressed in 42 out of 58 (72.4%). Oncogenic pathways were investigated by NanoString encounter technology in 5 PRDM1(+) and 5 PRDM1(‑) EN‑NK/T‑NT specimens. Multiple oncogenic pathways involved in cell apoptosis, cellcycle (CC) and angiogenesis were discriminately activated in EN‑NK/T‑NT cases, and in PRDM1(+) cases in particular. The sustained activation of the Janus kinase 3 (JAK)/STAT3 pathway was more pronounced. In addition, missense mutations in the SRC homology 2 domain of STAT3 were detected in 7 out of 37 EN‑NK/T‑NT cases (18.92%), and the acquired mutation was related to the activation of the JAK3/STAT3 pathway. The downregulation of PRDM1 and upregulation of phospho‑STAT3 (Tyr705) were associated with angiocentric infiltration of EN‑NK/T‑NT (P=0.039). Notably, the prognosis of patients in the PRDM1(+)/STAT3 [mutated (mut‑)] group was considerably improved than that of patients in the STAT3(mut+)/PRDM(‑) group (P=0.037). In addition, the inhibition of NK/T cell lymphoma cell lines by Stattic and tofacitinib could suppress cell proliferation by inducing cell apoptosis or arresting the CC. The present results revealed that the JAK3/STAT3 oncogenic pathway and PRDM1 expression could stratify clinicopathologic features of EN‑NK/T‑NT. The inhibition of the JAK3/STAT3 pathway may serve as a treatment option for EN‑NK/T‑NT.
Overexpression of PRDM5 promotes acute myeloid leukemia cell proliferation and migration by activating the JNK pathway.
Zhou Pan,Chen Xing,Li Mengke,Sun Xiaolu,Tan Jiaqi,Wang Xiaomin,Chu Yajing,Zhang Yicheng,Cheng Tao,Zhou Jianfeng,Wang Gaoxiang,Yuan Weiping
PRDM family proteins are dysregulated in many human diseases, especially hematological malignancies and solid cancers, and share a unique N-terminal PR domain followed by zinc fingers toward the C terminus. With a high frequency of DNA promoter hypermethylation, PRDM5 is primarily considered as a tumor suppressor in solid tumors. However, little is known about the function of PRDM5 in blood malignancies, especially acute myeloid leukemia (AML). In this study, we showed that high PRDM5 expression levels were independently correlated with poor overall survival in AML patients. PRDM5 overexpression promoted cell proliferation, colony formation, and migration in vitro and enhanced tumorigenesis in an in vivo xenograft model. Furthermore, we found that PRDM5 overexpression promoted cell cycle progression with the decreased level of cell cycle inhibitors such as p16 and p21, and regulated the expression of epithelial-mesenchymal transition markers ZO-1 and Vimentin to promote migration. Moreover, we observed that PRDM5 upregulated the Jun N-terminal kinase (JNK) signaling pathway and downregulated c-Myc expression. Pharmacological inhibition of JNK by SP600125 partially abrogated PRDM5-induced cell proliferation and migration. Taken together, our findings demonstrate that PRDM5 functions as an oncogenic driver in AML via JNK pathway, suggesting that PRDM5 is a potential therapeutic target for AML.
Genistein ameliorated obesity accompanied with adipose tissue browning and attenuation of hepatic lipogenesis in ovariectomized rats with high-fat diet.
Shen Hsin-Hsueh,Huang Shieh-Yang,Kung Ching-Wen,Chen Shu-Ying,Chen Ya-Fen,Cheng Pao-Yun,Lam Kwok-Keung,Lee Yen-Mei
The Journal of nutritional biochemistry
Estrogen deficiency in postmenopausal women is linked to the higher prevalence of obesity, type 2 diabetes and metabolic syndromes. Development of beige adipocytes (browning of WAT) increases energy expenditure and could be a promising strategy for obesity management. This study aimed to investigate the effects of phytoestrogen genistein (GEN) on white adipose tissue (WAT) inflammation, browning and hepatic lipogenesis in ovariectomized rats with high-fat diet (HFD) and further explore the underlying mechanism. Female Wistar rats received ovariectomy (Ovx) and HFD (45% fat) and then were administered with 17β-estradiol (E2, 3 times/week, subcutaneously) or GEN (15 mg/kg or 30 mg/kg, gavage, once daily) for 4 weeks. Administration of GEN decreased Ovx-induced body weight gain and adiposity and improved insulin sensitivity as well as increased insulin signaling p-IRS1 and p-AKT in retroperitoneal WAT. Adipocyte hypertrophy and production of proinflammatory cytokines MCP-1, TNF-α and IL-6 were reduced by GEN. It also suppressed the activation of NF-κB pathway evidenced by attenuation of p65 and phospho-IκB levels. Additionally, GEN elevated myokine irisin and promoted WAT browning by increasing UCP-1, PRDM-16, PGC-1α and CIDEA proteins and Ppargc1a, Ucp-1 and Tbx-1 mRNA in inguinal WAT which is associated with up-regulation of nuclear estrogen receptor-α. Plasma levels of triglyceride and cholesterol were reduced by GEN treatment accompanied with inhibition of lipogenic proteins (p-ACC, SREBP-1, FAS and CD36) in the liver. Long-term treatment with GEN attenuated estrogen-deficiency-induced obesity, WAT inflammation and hepatic lipogenesis and promoted the induction of WAT browning. It may provide a promising approach to prevent obesity during menopause.
PRDM5 identified as a target of epigenetic silencing in colorectal and gastric cancer.
Watanabe Yoshiyuki,Toyota Minoru,Kondo Yutaka,Suzuki Hiromu,Imai Takashi,Ohe-Toyota Mutsumi,Maruyama Reo,Nojima Masanori,Sasaki Yasushi,Sekido Yoshitaka,Hiratsuka Hiroyoshi,Shinomura Yasuhisa,Imai Kohzoh,Itoh Fumio,Tokino Takashi
Clinical cancer research : an official journal of the American Association for Cancer Research
PURPOSE:PR (PRDI-BF1 and RIZ) domain proteins (PRDM) are a subfamily of the kruppel-like zinc finger gene products that play key roles during cell differentiation and malignant transformation. The aim of the present study was to begin to examine the involvement of epigenetic alteration of PRDM expression in gastric and colorectal cancer. EXPERIMENTAL DESIGN:We used real-time PCR to assess expression of PRDM1-17. In addition, we used bisulfite PCR to assess DNA methylation and chromatin immunoprecipitation to assess histone modification in colorectal and gastric cancer cell lines lacking PRDM5 expression. RESULTS:Among the 17 PRDM family genes tested, we found that PRDM5 is the most frequently silenced in colorectal and gastric cancer cell lines. Silencing of PRDM5 was mediated by either DNA methylation or trimethylation of Lys(27) of histone H3. Introduction of PRDM5 into cancer cells suppressed cell growth, suggesting that it acts as a tumor suppressor in gastrointestinal cancers. Methylation of PRDM5 was detected in 6.6% (4 of 61) of primary colorectal and 50.0% (39 of 78) of primary gastric cancers but not in noncancerous tissue samples collected from areas adjacent to the tumors. CONCLUSIONS:Our data suggest that epigenetic alteration of PRDM5 (e.g., methylation of its 5'-CpG island or trimethylation of Lys(27) of histone H3) likely plays a key role in the progression of gastrointestinal cancers and may be a useful molecular marker.
Liraglutide improves insulin sensitivity in high fat diet induced diabetic mice through multiple pathways.
Zhou Joseph Yi,Poudel Anil,Welchko Ryan,Mekala Naveen,Chandramani-Shivalingappa Prashanth,Rosca Mariana Georgeta,Li Lixin
European journal of pharmacology
Glucagon like peptide-1 (GLP-1) promotes postprandial insulin secretion. Liraglutide, a full agonist of the GLP-1 receptor, reduces body weight, improve insulin sensitivity, and alleviate Non Alcoholic Fatty Liver Disease (NAFLD). However, the underlying mechanisms remain unclear. This study aims to explore the underlying mechanisms and cell signaling pathways involved in the anti-obesity and anti-inflammatory effects of liraglutide. Mice were fed a high fat high sucrose diet to induce diabetes, diabetic mice were divided into two groups and injected with liraglutide or vehicle for 14 days. Liraglutide treatment improved insulin sensitivity, accompanied with reduced expression of the phosphorylated Acetyl-CoA carboxylase-2 (ACC2) and upregulation of long chain acyl CoA dehydrogenase (LCAD) in insulin sensitive tissues. Furthermore, liraglutide induced adenosine monophosphate-activated protein kinase-α (AMPK-α) and Sirtuin-1(Sirt-1) protein expression in liver and perigonadal fat. Liraglutide induced elevation of fatty acid oxidation in these tissues may be mediated through the AMPK-Sirt-1 cell signaling pathway. In addition, liraglutide induced brown adipocyte differentiation in skeletal muscle, including induction of uncoupling protein-1 (UCP-1) and PR-domain-containing-16 (PRDM-16) protein in association with induction of SIRT-1. Importantly, liraglutide displayed anti-inflammation effect. Specifically, liraglutide led to a significant reduction in circulating interleukin-1 β (IL-1 β) and interleukin-6 (IL-6) as well as hepatic IL-1 β and IL-6 content. The expression of inducible nitric oxide synthase (iNOS-1) and cyclooxygenase-2 (COX-2) in insulin sensitive tissues was also reduced following liraglutide treatment. In conclusion, liraglutide improves insulin sensitivity through multiple pathways resulting in reduction of inflammation, elevation of fatty acid oxidation, and induction of adaptive thermogenesis.
High expression of PRDM14 correlates with cell differentiation and is a novel prognostic marker in resected non-small cell lung cancer.
Zhang Tiehong,Meng Long,Dong Wei,Shen Hongchang,Zhang Shuming,Liu Qi,Du Jiajun
Medical oncology (Northwood, London, England)
PR (PRDI-BF1 and RIZ) domain containing proteins (PRDM) have been indicated to play important roles in several human cancers. The objectives of this study were to determine the frequency and prognostic significance of PRDM1 and PRDM14 expression in a cohort of surgically resected non-small cell lung cancer (NSCLC) patients. Immunohistochemistry and Western blotting was used to detect the expression status of PRDM1 in primary tumors and PRDM14 for both primary lung cancers and matched lymph node metastases. Univariate and multivariate analysis were performed to determine the association between PRDM expression and prognosis. PRDM1 expression was observed in all NSCLC patients' tumor samples. PRDM14 was found to be increased expression in 35.65 % cases (46/129) for primary tumors and 39.68 % cases (25/63) for paired metastatic lymph nodes. Increased expression of PRDM14 correlated with differentiation of tumor cells significantly (P = 0.008). Western blotting analysis verified that PRDM14 associated with cell differentiation in NSCLC. The overall survival rates of patients with high PRDM14 expression and low PRDM14 expression were 41.30 and 65.06 %, respectively (hazard ratio: 3.051, 95 % CI: 1.752, 5.312, P < 0.0001). The progression-free survival rates were 34.78 % for patients in the high expression group and 59.03 % for patients in the low OLC1 expression group (hazard ratio: 2.775, 95 % CI: 1.648, 4.675, P < 0.0001). Thus, our study showed that increased expression of PRDM14 correlated with cell differentiation of NSCLC cells. PRDM14 was a potential biomarker for predicting unfavorable prognosis in NSCLC.
Resveratrol and Oxyresveratrol Activate Thermogenesis via Different Transcriptional Coactivators in High-Fat Diet-Induced Obese Mice.
Pan Min-Hsiung,Koh Yen-Chun,Lee Tzu-Ling,Wang Bini,Chen Wen-Kang,Nagabhushanam Kalyanam,Ho Chi-Tang
Journal of agricultural and food chemistry
Obesity is a global public health issue. Thermogenesis is a novel way to promote anti-obesity by consuming energy as heat rather than storing it as triacylglycerols. The browning program allows mitochondrial biosynthesis and thermogenesis-related gene expression to occur in subcutaneous white adipose tissue, which results in the formation of beige adipose tissue. Some phytochemicals have exerted the capability to activate the fat browning process. Resveratrol and oxyresveratrol are both natural stilbenoids that have been reported for their anti-obesity efficacy. However, the comparison between the two as they relate to thermogenesis as well as the differences in their underlying mechanisms are still not widely discussed. Our result reveals that both resveratrol and oxyresveratrol could elevate the expression of thermogenesis-related protein expression including UCP1 (uncoupling protein-1) and PRDM (PR domain containing 16) via Sirt1/PGC-1α (sirtuin 1/peroxisome proliferation gamma coactivator-1 α) activation. However, it is suggested that the transcriptional factor PPARα (peroxisome proliferator-activator receptor α) was activated by resveratrol (1.38 ± 0.07 fold) but not oxyresveratrol. Conversely, C/EBPβ (CCAAT/enhancer-binding protein β) was upregulated by oxyresveratrol (1.58 ± 0.05 fold) but not by resveratrol. On the other hand, CPT1 (carnitine palmitoyltransferase) was found to be significantly activated at lower concentrations of oxyresveratrol up to 1.89 ± 0.04 fold as compared to high-fat diet, and it could be a leading reason for UCP1 activation. Lastly, adiponectin expression was promoted in all experimental groups (1.53 ± 0.08 and 1.49 ± 0.11-fold in resveratrol (RES) and high oxyresveratrol (HOXY), respectively), which could be an activator for mitochondrial biosynthesis and UCP1 expression.
Discovery of a chemical probe for PRDM9.
Allali-Hassani Abdellah,Szewczyk Magdalena M,Ivanochko Danton,Organ Shawna L,Bok Jabez,Ho Jessica Sook Yuin,Gay Florence P H,Li Fengling,Blazer Levi,Eram Mohammad S,Halabelian Levon,Dilworth David,Luciani Genna M,Lima-Fernandes Evelyne,Wu Qin,Loppnau Peter,Palmer Nathan,Talib S Zakiah A,Brown Peter J,Schapira Matthieu,Kaldis Philipp,O'Hagan Ronan C,Guccione Ernesto,Barsyte-Lovejoy Dalia,Arrowsmith Cheryl H,Sanders John M,Kattar Solomon D,Bennett D Jonathan,Nicholson Benjamin,Vedadi Masoud
PRDM9 is a PR domain containing protein which trimethylates histone 3 on lysine 4 and 36. Its normal expression is restricted to germ cells and attenuation of its activity results in altered meiotic gene transcription, impairment of double-stranded breaks and pairing between homologous chromosomes. There is growing evidence for a role of aberrant expression of PRDM9 in oncogenesis and genome instability. Here we report the discovery of MRK-740, a potent (IC: 80 ± 16 nM), selective and cell-active PRDM9 inhibitor (Chemical Probe). MRK-740 binds in the substrate-binding pocket, with unusually extensive interactions with the cofactor S-adenosylmethionine (SAM), conferring SAM-dependent substrate-competitive inhibition. In cells, MRK-740 specifically and directly inhibits H3K4 methylation at endogenous PRDM9 target loci, whereas the closely related inactive control compound, MRK-740-NC, does not. The discovery of MRK-740 as a chemical probe for the PRDM subfamily of methyltransferases highlights the potential for exploiting SAM in targeting SAM-dependent methyltransferases.
Adipose tissue lipolysis and energy metabolism in early cancer cachexia in mice.
Kliewer Kara L,Ke Jia-Yu,Tian Min,Cole Rachel M,Andridge Rebecca R,Belury Martha A
Cancer biology & therapy
Cancer cachexia is a progressive metabolic disorder that results in depletion of adipose tissue and skeletal muscle. A growing body of literature suggests that maintaining adipose tissue mass in cachexia may improve quality-of-life and survival outcomes. Studies of lipid metabolism in cachexia, however, have generally focused on later stages of the disorder when severe loss of adipose tissue has already occurred. Here, we investigated lipid metabolism in adipose, liver and muscle tissues during early stage cachexia - before severe fat loss - in the colon-26 murine model of cachexia. White adipose tissue mass in cachectic mice was moderately reduced (34-42%) and weight loss was less than 10% of initial body weight in this study of early cachexia. In white adipose depots of cachectic mice, we found evidence of enhanced protein kinase A - activated lipolysis which coincided with elevated total energy expenditure and increased expression of markers of brown (but not white) adipose tissue thermogenesis and the acute phase response. Total lipids in liver and muscle were unchanged in early cachexia while markers of fatty oxidation were increased. Many of these initial metabolic responses contrast with reports of lipid metabolism in later stages of cachexia. Our observations suggest intervention studies to preserve fat mass in cachexia should be tailored to the stage of cachexia. Our observations also highlight a need for studies that delineate the contribution of cachexia stage and animal model to altered lipid metabolism in cancer cachexia and identify those that most closely mimic the human condition.
Investigation of PRDM7 and PRDM12 expression pattern during mouse embryonic development by using a modified passive clearing technique.
Woo Jiwon,Kang Haewon,Lee Eunice Yoojin,Park Sangkyu,Cho Yong Eun
Biochemical and biophysical research communications
Recent developments in tissue clearing methods such as CLARITY (Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging/Immunostaining/In situ hybridization-compatible Tissue hYdrogel) have allowed for the three-dimensional analysis of biological structures in whole, intact tissue, providing greater understanding of spatial relationships and biological circuits. Nonetheless, studies have reported issues with maintaining structural integrity and preventing tissue disintegration, preventing the wide application of these techniques to fragile tissues such as developing embryos. Here, we present optimized passive clearing techniques, mPACT-A, that improve tissue rigidity without the expense of optical transparency. We also present a further modified mPACT-A protocol that is specifically optimized for handling mouse embryos, which are small and fragile, such that they easily dismantle when processed via established tissue clearing methods. We demonstrate proof-of-concept by investigating the expression of two relatively understudied PRDM proteins, PRDM7 and PRDM12, in intact cleared mouse embryos at various stages of development. We observed strong PRDM7 and PRDM12 expression in the developing mouse nervous system, suggestive of potential roles in neural development that will be tested in future functional studies.
The PR/SET domain zinc finger protein Prdm4 regulates gene expression in embryonic stem cells but plays a nonessential role in the developing mouse embryo.
Bogani Debora,Morgan Marc A J,Nelson Andrew C,Costello Ita,McGouran Joanna F,Kessler Benedikt M,Robertson Elizabeth J,Bikoff Elizabeth K
Molecular and cellular biology
Prdm4 is a highly conserved member of the Prdm family of PR/SET domain zinc finger proteins. Many well-studied Prdm family members play critical roles in development and display striking loss-of-function phenotypes. Prdm4 functional contributions have yet to be characterized. Here, we describe its widespread expression in the early embryo and adult tissues. We demonstrate that DNA binding is exclusively mediated by the Prdm4 zinc finger domain, and we characterize its tripartite consensus sequence via SELEX (systematic evolution of ligands by exponential enrichment) and ChIP-seq (chromatin immunoprecipitation-sequencing) experiments. In embryonic stem cells (ESCs), Prdm4 regulates key pluripotency and differentiation pathways. Two independent strategies, namely, targeted deletion of the zinc finger domain and generation of a EUCOMM LacZ reporter allele, resulted in functional null alleles. However, homozygous mutant embryos develop normally and adults are healthy and fertile. Collectively, these results strongly suggest that Prdm4 functions redundantly with other transcriptional partners to cooperatively regulate gene expression in the embryo and adult animal.
Prdm12 specifies V1 interneurons through cross-repressive interactions with Dbx1 and Nkx6 genes in Xenopus.
Thélie Aurore,Desiderio Simon,Hanotel Julie,Quigley Ian,Van Driessche Benoit,Rodari Anthony,Borromeo Mark D,Kricha Sadia,Lahaye François,Croce Jenifer,Cerda-Moya Gustavo,Ordoño Fernandez Jesús,Bolle Barbara,Lewis Katharine E,Sander Maike,Pierani Alessandra,Schubert Michael,Johnson Jane E,Kintner Christopher R,Pieler Tomas,Van Lint Carine,Henningfeld Kristine A,Bellefroid Eric J,Van Campenhout Claude
Development (Cambridge, England)
V1 interneurons are inhibitory neurons that play an essential role in vertebrate locomotion. The molecular mechanisms underlying their genesis remain, however, largely undefined. Here, we show that the transcription factor Prdm12 is selectively expressed in p1 progenitors of the hindbrain and spinal cord in the frog embryo, and that a similar restricted expression profile is observed in the nerve cord of other vertebrates as well as of the cephalochordate amphioxus. Using frog, chick and mice, we analyzed the regulation of Prdm12 and found that its expression in the caudal neural tube is dependent on retinoic acid and Pax6, and that it is restricted to p1 progenitors, due to the repressive action of Dbx1 and Nkx6-1/2 expressed in the adjacent p0 and p2 domains. Functional studies in the frog, including genome-wide identification of its targets by RNA-seq and ChIP-Seq, reveal that vertebrate Prdm12 proteins act as a general determinant of V1 cell fate, at least in part, by directly repressing Dbx1 and Nkx6 genes. This probably occurs by recruiting the methyltransferase G9a, an activity that is not displayed by the amphioxus Prdm12 protein. Together, these findings indicate that Prdm12 promotes V1 interneurons through cross-repressive interactions with Dbx1 and Nkx6 genes, and suggest that this function might have only been acquired after the split of the vertebrate and cephalochordate lineages.
Genomic and proteomic analyses of Prdm5 reveal interactions with insulator binding proteins in embryonic stem cells.
Galli Giorgio Giacomo,Carrara Matteo,Francavilla Chiara,de Lichtenberg Kristian Honnens,Olsen Jesper Velgaard,Calogero Raffaele Adolfo,Lund Anders Henrik
Molecular and cellular biology
PRDM proteins belong to the SET domain protein family, which is involved in the regulation of gene expression. Although few PRDM members possess histone methyltransferase activity, the molecular mechanisms by which the other members exert transcriptional regulation remain to be delineated. In this study, we find that Prdm5 is highly expressed in mouse embryonic stem (mES) cells and exploit this cellular system to characterize molecular functions of Prdm5. By combining proteomics and next-generation sequencing technologies, we identify Prdm5 interaction partners and genomic occupancy. We demonstrate that although Prdm5 is dispensable for mES cell maintenance, it directly targets genomic regions involved in early embryonic development and affects the expression of a subset of developmental regulators during cell differentiation. Importantly, Prdm5 interacts with Ctcf, cohesin, and TFIIIC and cooccupies genomic loci. In summary, our data indicate how Prdm5 modulates transcription by interacting with factors involved in genome organization in mouse embryonic stem cells.
Prdm5 suppresses Apc(Min)-driven intestinal adenomas and regulates monoacylglycerol lipase expression.
Galli G G,Multhaupt H A,Carrara M,de Lichtenberg K H,Christensen I B J,Linnemann D,Santoni-Rugiu E,Calogero R A,Lund A H
PRDM proteins are tissue-specific transcription factors often deregulated in diseases, particularly in cancer where different members have been found to act as oncogenes or tumor suppressors. PRDM5 is a poorly characterized member of the PRDM family for which several studies have reported a high frequency of promoter hypermethylation in cancer types of gastrointestinal origin. We report here the characterization of Prdm5 knockout mice in the context of intestinal carcinogenesis. We demonstrate that loss of Prdm5 increases the number of adenomas throughout the murine small intestine on an Apc(Min) background. By using the genome-wide ChIP-seq (chromatin immunoprecipitation (ChIP) followed by DNA sequencing) and transcriptome analyses we identify loci encoding proteins involved in metabolic processes as prominent PRDM5 targets and characterize monoacylglycerol lipase (Mgll) as a direct PRDM5 target in human colon cancer cells and in Prdm5 mutant mouse intestines. Moreover, we report the downregulation of PRDM5 protein expression in human colon neoplastic lesions. In summary, our data provide the first causal link between Prdm5 loss and intestinal carcinogenesis, and uncover an extensive and novel PRDM5 target repertoire likely facilitating the tumor-suppressive functions of PRDM5.
PRDM14: a unique regulator for pluripotency and epigenetic reprogramming.
Nakaki Fumio,Saitou Mitinori
Trends in biochemical sciences
PRDM14 belongs to the PR domain-containing (PRDM) transcriptional regulators. Among the PRDM family members, PRDM14 shows specific expression in preimplantation embryos, primordial germ cells (PGCs), and embryonic stem cells (ESCs) in vitro, and accordingly plays a key role in the regulation of their pluripotency and epigenetic reprogramming, most notably, genome-wide DNA demethylation. The function of PRDM14 appears to be conserved between mice and humans, but it shows several characteristic differences between the two species. A precise understanding of the function of PRDM14 in mice and humans would shed new light on the regulation of pluripotency and the epigenome in these two species, providing a foundation for better control of stem cell fates in a broader context.
Regulation of Hox orthologues in the oyster Crassostrea gigas evidences a functional role for promoter DNA methylation in an invertebrate.
Saint-Carlier Emma,Riviere Guillaume
DNA methylation within promoter regions (PRDM) controls vertebrate early gene transcription and thereby development, but is neglected outside this group. However, epigenetic features in the oyster Crassostrea gigas suggest functional significance of PDRM in invertebrates. To investigate this, reporter constructs containing in vitro methylated oyster Hox gene promoters were transfected into oyster embryos. The influence of in vivo methylation was studied using bisulfite sequencing and DNA methyltransferase inhibition during development. Our results demonstrate that methylation controls the transcriptional activity of the promoters investigated, unraveling a functional role for PRDM in a lophotrochozoan, an important finding regarding the evolution of epigenetic regulation.
Beiging of white adipose tissue as a therapeutic strategy for weight loss in humans.
Thyagarajan Baskaran,Foster Michelle T
Hormone molecular biology and clinical investigation
An imbalance between energy intake and expenditure leads to obesity. Adiposity associated with obesity progressively causes inflammation, type 2 diabetes, hypertension, hyperlipidemia and cardiovascular disease. Excessive dietary intake of fat results in its accumulation and storage in the white adipose tissue (WAT), whereas energy expenditure by fat utilization and oxidation predominately occurs in the brown adipose tissue (BAT). Recently, the presence of a third type of fat, referred to as beige or brite (brown in white), has been recognized in certain kinds of WAT depots. It has been suggested that WAT can undergo the process of browning in response to stimuli that induce and enhance the expression of thermogenes characteristic of those typically associated with brown fat. The resultant beige or brite cells enhance energy expenditure by reducing lipids stored within adipose tissue. This has created significant excitement towards the development of a promising strategy to induce browning/beiging in WAT to combat the growing epidemic of obesity. This review systematically describes differential locations and functions of WAT and BAT, mechanisms of beiging of WAT and a concise analysis of drug molecules and natural products that activate the browning phenomenon in vitro and in vivo. This review also discusses potential approaches for targeting WAT with compounds for site-specific beiging induction. Overall, there are numerous mechanisms that govern browning of WAT. There are a variety of newly identified targets whereby potential molecules can promote beiging of WAT and thereby combat obesity.
Role of PRDM16 and its PR domain in the epigenetic regulation of myogenic and adipogenic genes during transdifferentiation of C2C12 cells.
Li Xiao,Wang Jinquan,Jiang Zheng,Guo Feng,Soloway Paul D,Zhao Ruqian
The positive regulatory domain containing 16 (PRDM16) is commonly regarded as a "switch" controlling the transdifferentiation of myoblasts to brown adipocytes. The N-positive regulatory (PR) domain, which is highly homologous to SET domain, is a characteristic structure for the PRDM family. Many SET domain containing proteins and several PRDM members have been found to possess histone methyltransferase activity, yet the role of PRDM16 and its PR domain in the epigenetic regulation of myogenic and adipogenic genes during myoblasts/adipocytes transdifferentiation remains unexplored. In this study, we transfected C2C12 myoblasts to stably express PRDM16 and observed the repression of myogenic genes and activation of adipogenic genes at both proliferation and differentiation stages. Ectopic PRDM16-induced reprogramming of myogenic and adipogenic genes was associated with the hypermethylation on some CpG sites in the enhancer or promoter of MyoD and myogenin, but the methylation status of PPARγ promoter was not affected. C2C12 cells expressing truncated PRDM16 lacking PR domain (ΔPR-PRDM16) demonstrated attenuation of both adipogenic and myogenic potentials, indicated by PPARγ inactivation and decreased triglyceride deposition, as well as a downregulation of MyoD, MyHC and MCK genes, as compared with C2C12 cells expressing intact PRDM16. Furthermore, C2C12 cells expressing ΔPR-PRDM16 exhibited significant differences in histone modifications on the promoters of MyoD and PPARγ genes. Taken together, PRDM16-induced C2C12 transdifferentiation is associated with alterations in CpG methylation of myogenic factors, and PR domain affects both myogenesis and adipogenesis with modified histone methylation marks on MyoD and PPARγ promoters.
The role of PRDMs in cancer: one family, two sides.
Mzoughi Slim,Tan Ying Xim,Low Diana,Guccione Ernesto
Current opinion in genetics & development
The PRDM family of proteins share a unique structure, with an N-terminal PR domain, which has a potential methyltransferase activity, followed by a distinct number of zinc fingers at the C-terminus, potentially mediating protein-protein, protein-RNA or protein-DNA interactions. Interestingly, despite no comprehensive functional data, all family members have been associated with deletions, mutations, epigenetic silencing or overexpression, in multiple cancer types. The intriguing observation is that different isoforms exist for almost all PRDM family members. These isoforms are not only differentially regulated, but play opposite roles in cancer, in what has been termed 'Yin and Yang' regulation, typical of this class of epigenetic regulators. Collectively, these findings set the stage for future intervention, by targeting directly their intrinsic catalytic activities, or indirectly, pathways that differentially regulate tumor suppressor/oncogenic isoform-expression.
PRDM5 promotes the proliferation and invasion of murine melanoma cells through up-regulating JNK expression.
Wang Lei,Ding Qiong-Qiong,Gao Shan-Shan,Yang Hai-Jie,Wang Mian,Shi Yu,Cheng Bin-Feng,Bi Jia-Jia,Feng Zhi-Wei
PRDM (PRDI-BF1 and RIZ domain-containing) proteins constitute a family of zinc finger proteins and play important roles in multiple cellular processes by acting as epigenetic modifiers. PRDM5 is a recently identified member of the PRDM family and may function as a tumor suppressor in several types of cancer. However, the role of PRDM5 in murine melanoma remains largely unknown. In our study, effect of PRDM5 on murine melanoma cells was determined and results showed that PRDM5 overexpression significantly promoted proliferation, migration, and invasion of murine melanoma B16F10 cells. Consistently, silencing of PRDM5 expression significantly inhibited proliferation, invasion, and migration of B16F10 cells. In vivo study also showed that PRDM5 silencing significantly inhibited the growth and metastasis of melanoma in mice. PRDM5 was then found to increase the expression and activation of JNK in B16F10 cells. JNK silencing significantly reduced PRDM5-mediated up-regulation of JNK expression and blocked the PRDM5-induced proliferation and invasion of B16F10 cells. To further verify the involvement of JNK signaling in PRDM5-induced progression of B16F10 cells, a specific JNK inhibitor was employed to inhibit the JNK signaling pathway, and results showed that PRDM5-induced proliferation and invasion of B16F10 cells were abolished. We conclude that PRDM5 promotes the proliferation and invasion of murine melanoma cells through up-regulating JNK expression and strategies targeting PRDM5 may be promising for the therapy of melanoma.
Capsaicin induces browning of white adipose tissue and counters obesity by activating TRPV1 channel-dependent mechanisms.
Baskaran Padmamalini,Krishnan Vivek,Ren Jun,Thyagarajan Baskaran
British journal of pharmacology
BACKGROUND AND PURPOSE:The growing epidemic of obesity and metabolic diseases necessitates the development of novel strategies to prevent and treat such diseases. Current research suggests that browning of white adipose tissue (WAT) promotes energy expenditure to counter obesity. Recent research suggests that activation of the TRPV1 channels counters obesity. However, the mechanism by which activation of TRPV1 channels counters obesity still remains unclear. EXPERIMENTAL APPROACH:We evaluated the effect of dietary capsaicin to induce a browning program in WAT by activating TRPV1 channels to prevent diet-induced obesity using wild-type and TRPV1(-/-) mouse models. We performed experiments using preadipocytes and fat pads from these mice. KEY RESULTS:Capsaicin stimulated the expression of brown fat-specific thermogenic uncoupling protein-1 and bone morphogenetic protein-8b in WAT. Capsaicin triggered browning of WAT by promoting sirtuin-1 expression and activity via TRPV1 channel-dependent elevation of intracellular Ca(2) (+) and phosphorylation of Ca(2) (+) /calmodulin-activated protein kinase II and AMP-activated kinase. Capsaicin increased the expression of PPARγ 1 coactivator α and enhanced metabolic and ambulatory activity. Further, capsaicin stimulated sirtuin-1-dependent deacetylation of PPARγ and the transcription factor PRDM-16 and facilitated PPARγ-PRDM-16 interaction to induce browning of WAT. Dietary capsaicin did not protect TRPV1(-/-) mice from obesity. CONCLUSIONS AND INTERPRETATIONS:Our results show for the first time that activation of TRPV1 channels by dietary capsaicin triggers browning of WAT to counteract obesity. Our results suggest that activation of TRPV1 channels is a promising strategy to counter obesity.
sequoia controls the type I>0 daughter proliferation switch in the developing Drosophila nervous system.
Gunnar Erika,Bivik Caroline,Starkenberg Annika,Thor Stefan
Development (Cambridge, England)
Neural progenitors typically divide asymmetrically to renew themselves, while producing daughters with more limited potential. In the Drosophila embryonic ventral nerve cord, neuroblasts initially produce daughters that divide once to generate two neurons/glia (type I proliferation mode). Subsequently, many neuroblasts switch to generating daughters that differentiate directly (type 0). This programmed type I>0 switch is controlled by Notch signaling, triggered at a distinct point of lineage progression in each neuroblast. However, how Notch signaling onset is gated was unclear. We recently identified Sequoia (Seq), a C2H2 zinc-finger transcription factor with homology to Drosophila Tramtrack (Ttk) and the positive regulatory domain (PRDM) family, as important for lineage progression. Here, we find that seq mutants fail to execute the type I>0 daughter proliferation switch and also display increased neuroblast proliferation. Genetic interaction studies reveal that seq interacts with the Notch pathway, and seq furthermore affects expression of a Notch pathway reporter. These findings suggest that seq may act as a context-dependent regulator of Notch signaling, and underscore the growing connection between Seq, Ttk, the PRDM family and Notch signaling.
Dynamic covalent chemistry in aqueous solution by photoinduced radical disulfide metathesis.
Klepel Florian,Ravoo Bart Jan
Organic & biomolecular chemistry
Photoinduced radical disulfide metathesis (PRDM) is a dynamic covalent reaction that requires UV light to induce the homolytic cleavage of the disulfide bond, thus offering the opportunity to construct dynamic covalent systems that are dormant and can be photo-activated on demand. In this work, we showcase how PRDM can be utilized in aqueous solution and demonstrate its potential by generating a UV responsive hydrogel from an asymmetrical disulfide precursor.
Differential regulation of SC1/PRDM4 and PRMT5 mediated protein arginine methylation by the nerve growth factor and the epidermal growth factor in PC12 cells.
During neuronal development, the neuroepithelial stem cells (NSCs) initially undergo proliferative divisions, later switching to neurogenic ones whereby one NSC and a post-mitotic neuron are generated. We recently showed that a member of the PRDM family of transcriptional regulators, PRDM4/SC1, recruits a type II protein arginine methyltransferase, PRMT5, to maintain the "stem-like" cellular state of the embryonic mouse cortical NSCs. However, little is known about the regulation of activity of this complex under proliferation- or differentiation-inducing growth conditions. In the present work I investigate the regulation of SC1/PRMT5-mediated methylation activity in PC12 cells treated with EGF or NGF. I present evidence that NGF down-regulates SC1/PRMT5 methyltransferase (MTase) activity and that the reduction in SC1/PRMT5 MTase activity occurs mainly in the nucleus. I suggest that high levels of SC1/PRMT5 activity are associated with the proliferative state of the cells.
Zebrafish serotonin-N-acetyltransferase-2 gene regulation: pineal-restrictive downstream module contains a functional E-box and three photoreceptor conserved elements.
Appelbaum Lior,Toyama Reiko,Dawid Igor B,Klein David C,Baler Ruben,Gothilf Yoav
Molecular endocrinology (Baltimore, Md.)
Pineal function is defined by a set of very narrowly expressed genes that encode proteins required for photoperiodic transduction and rhythmic melatonin secretion. One of these proteins is serotonin N-acetyltransferase (arylalkylamine N-acetyltransferase, AANAT), which controls the daily rhythm in melatonin production. Here, pineal-specific expression of the zebrafish aanat-2 (zfaanat-2) was studied using in vivo transient expression analyses of promoter-reporter constructs; this revealed that specificity is determined by two regions located 12 kb away from each other. One is the 5'-flanking region, and the other is a 257-bp sequence, located 6 kb downstream of the transcribed region. This 3'-sequence, designated pineal-restrictive downstream module (PRDM), has a dual function: enhancement of pineal expression and inhibition of extrapineal expression. The former is an autonomic property of PRDM whereas the later function requires interaction with the upstream regulatory region of zfaanat-2. Functional analyses of the PRDM sequence revealed that three photoreceptor conserved elements (TAATC) and a single perfect E-box (CACGTG) are crucial for the dual function of PRDM. These results indicate that pineal specificity of zfaanat-2 is determined by the dual functionality of the PRDM and the interaction between upstream regulatory region and downstream photoreceptor conserved elements and E-box element.
Overexpression of PRDM13 inhibits glioma cells via Rho and GTP enzyme activation protein.
Zhang Linna,Cao Huimei,He Tao,Yang Jijuan,Tao Hong,Wang Yin,Hu Qikuan
International journal of molecular medicine
PR (PRDI‑BFI and RIZ) domain containing (PRDM) proteins have been shown to be important in several types of human cancer. PRDM13, a member of the PRDM family, contains transcriptional regulators involved in modulating several cellular processes. However, the function of PRDM13 in glioma remains to be elucidated. The purpose of the present study was to evaluate the expression and effect of PRDM13 on glioma cells. It was found that the expression of PRDM13 was reduced in glioma cells, and the overexpression of PRDM13 significantly decreased the proliferation, migration and invasion of U87 glioma cells. Through validation of RNA‑sequencing analysis, genes regulating cell proliferation and migration were classified from Gene Ontology sources. In addition, PRDM13 was shown to be associated with Rho protein and GTP enzyme activation protein. The over-expression of PRDM13 upregulated deleted in liver cancer 1 (DLC1) to inhibit the proliferation and invasion of U87 cells. In conclusion, PRDM13 decreased the proliferation and invasion of U87 cells, and may be of potential value for glioma therapy.
[Relationship of Blimp-1 Hypoexpression with Pathogenesis of Aplastic Anemia].
Chen Qi-Hui,Wang Jian,Lin Shao-Fen,Liu Su,Xue Hong-Man,Chen Chun
Zhongguo shi yan xue ye xue za zhi
OBJECTIVE:To study the relationship of Blimp-1 hypoexpression with abnormality of Treg level and pathogenesis of aplastic anemia (AA). METHODS:The mouse model with AA was established by adminis tration of IFN-γ combined with busulfan. The samples were collected at different day establishing AA model, and the spleen Treg number was detected, the Treg cells were sorted and expression level of prdm-1 was detected. RESULTS:The number of Tregs in mice with AA was lower than that in control mice, moreover, the level of Treg decrease positively correlated with the AA severity (r=0.805), the higher the expression level of prdm-1, the higher the ratio of Treg/lymphocytes, showing positive correlation between them (r=0.548). CONCLUSION:Blimp-1 expression may promote the proliferation and differentiation of Treg. The hypoexpression of Blimp-1 mediates the pathogenesis of AA and promotes progression of AA through reducing the proliferation of Treg, and decreacing the number of Treg.
Effects of visfatin on brown adipose tissue energy regulation using T37i cells.
Dimitriadis Georgios K,Adya Raghu,Tan Bee K,Jones Terence A,Menon Vinod S,Ramanjaneya Manjunath,Kaltsas Gregory,Miras Alexander D,Randeva Harpal S
The role of brown adipose tissue (BAT) in pathological states of energy homeostasis and impaired adipocyte function, such as obesity has been a major area of research interest in recent years. Herein, we sought to determine the direct effects of adipokines, visfatin and leptin on BAT thermogenesis. The effects of mouse recombinant visfatin, nicotinamide mononucleotide (NMN) and leptin with or without FK866 were studied on differentiated T37i cells. Treated cells were analyzed for key genes and proteins regulating BAT [UCP-1, PRD1-BF1-RIZ1 homologous domain-containing 16 (PRDM-16), PPARgamma-coactivator-1alpha (PGC-1α) and receptor-interacting protein 140 (RIP-140)] using quantitative PCR and western blot analysis. Data is presented as mean P-values. Both visfatin and leptin had significant concentration dependent effects on thermogenesis in brown pre-adipocytes and at physiological levels, increased uncoupling protein-1 (UCP-1) levels in brown adipocytes. These effects of visfatin were similar to that of nicotinamide mononucleotide (NMN), further strengthening the enzymatic role of visfatin. We also showed that leptin induced UCP-1 mRNA expression and protein production appears to be mediated by visfatin. High concentrations of both visfatin and leptin led to a dramatic decrease in UCP-1 protein levels, supporting the notion that visfatin levels are raised in obesity and that obese people have reduced BAT activity, plausibly through a reduction in UCP-1 levels. Additionally, we found differential regulation of key brown adipogenic genes, specifically, PRD1-BF1-RIZ1 homologous domain-containing 16 (PRDM-16), PPARgamma-coactivator-1alpha (PGC-1α) and receptor-interacting protein 140 (RIP-140) by visfatin. Our observations provide novel insights in the potential actions of visfatin in BAT.
Depletion of PRDM9 enhances proliferation, migration and chemotaxis potentials in human periodontal ligament stem cells.
Zhang Jianpeng,Zhang Chen,Yang Haoqing,Han Xiao,Fan Zhipeng,Hou Benxiang
Connective tissue research
PURPOSE:Periodontal ligament mesenchymal stem cells (PDLSCs) are important for periodontal tissue regeneration, but how these cells are regulated remains unclear. PRDM (PRDI-BF1 and RIZ homology domain containing) genes play key roles in cell proliferation and differentiation. The present study aimed to investigate the role of one PRDM gene, PRDM9, in the proliferation, migration and chemotaxis potential of PDLSCs. MATERIALS AND METHODS:Cell proliferation was examined on the basis of the cell doubling time, cell counting kit-8 (CCK8) assays, and flow cytometry analysis of the cell cycle. Gene expression was detected by Western blotting and real-time RT-PCR. Scratch migration and Transwell chemotaxis assays were used to analyse cell migration and chemotaxis abilities. Microarray analysis and ChIP assays were used to examine the downstream genes of PRDM9 and the corresponding mechanism. RESULTS:The results showed that knock-down of PRDM9 enhanced cell proliferation by promoting cell cycle progression and rapid transition from the G1 to S phase via downregulation of p21 and p27 and upregulation of cyclin E. Additionally, depletion of PRDM9 increased the migration and chemotaxis potential of PDLSCs. Microarray results showed that 13 genes, including , and , were upregulated and 34 genes, including PIP, were downregulated after the depletion of PRDM9. Furthermore, we observed that the depletion of PRDM9 promoted the transcription of IGFBP5 by increasing H3K4me3 methylation in the IGFBP5 promoter. CONCLUSION:These discoveries indicated that depletion of PRDM9 increased the cell proliferation, migration and chemotaxis potential of PDLSCs and revealed important downstream genes.
The conserved and divergent roles of Prdm3 and Prdm16 in zebrafish and mouse craniofacial development.
Shull Lomeli Carpio,Sen Rwik,Menzel Johannes,Goyama Susumu,Kurokawa Mineo,Artinger Kristin Bruk
The formation of the craniofacial skeleton is a highly dynamic process that requires proper orchestration of various cellular processes in cranial neural crest cell (cNCC) development, including cell migration, proliferation, differentiation, polarity and cell death. Alterations that occur during cNCC development result in congenital birth defects and craniofacial abnormalities such as cleft lip with or without cleft palate. While the gene regulatory networks facilitating neural crest development have been extensively studied, the epigenetic mechanisms by which these pathways are activated or repressed in a temporal and spatially regulated manner remain largely unknown. Chromatin modifiers can precisely modify gene expression through a variety of mechanisms including histone modifications such as methylation. Here, we investigated the role of two members of the PRDM (Positive regulatory domain) histone methyltransferase family, Prdm3 and Prdm16 in craniofacial development using genetic models in zebrafish and mice. Loss of prdm3 or prdm16 in zebrafish causes craniofacial defects including hypoplasia of the craniofacial cartilage elements, undefined posterior ceratobranchials, and decreased mineralization of the parasphenoid. In mice, while conditional loss of Prdm3 in the early embryo proper causes mid-gestation lethality, loss of Prdm16 caused craniofacial defects including anterior mandibular hypoplasia, clefting in the secondary palate and severe middle ear defects. In zebrafish, prdm3 and prdm16 compensate for each other as well as a third Prdm family member, prdm1a. Combinatorial loss of prdm1a, prdm3, and prdm16 alleles results in severe hypoplasia of the anterior cartilage elements, abnormal formation of the jaw joint, complete loss of the posterior ceratobranchials, and clefting of the ethmoid plate. We further determined that loss of prdm3 and prdm16 reduces methylation of histone 3 lysine 9 (repression) and histone 3 lysine 4 (activation) in zebrafish. In mice, loss of Prdm16 significantly decreased histone 3 lysine 9 methylation in the palatal shelves but surprisingly did not change histone 3 lysine 4 methylation. Taken together, Prdm3 and Prdm16 play an important role in craniofacial development by maintaining temporal and spatial regulation of gene regulatory networks necessary for proper cNCC development and these functions are both conserved and divergent across vertebrates.
The Impact of Moderate-Intensity Continuous or High-Intensity Interval Training on Adipogenesis and Browning of Subcutaneous Adipose Tissue in Obese Male Rats.
Khalafi Mousa,Mohebbi Hamid,Symonds Michael E,Karimi Pouran,Akbari Amir,Tabari Elma,Faridnia Mehrsa,Moghaddami Kamilia
This study compares the effect of two types of exercise training, i.e., moderate-intensity continuous training (MICT) or high-intensity interval training (HIIT) on the browning of subcutaneous white adipose tissue (scWAT) in obese male rats. Effects on fat composition, metabolites, and molecular markers of differentiation and energy expenditure were examined. Forty male Wistar rats were assigned to lean ( = 8) or obese ( = 32) groups and fed either a standard chow or high-fat obesogenic diet for 10 weeks. Eight lean and obese rats were then blood and tissue sampled, and the remaining obese animals were randomly allocated into sedentary, MICT, or HIIT (running on a treadmill 5 days/week) groups that were maintained for 12 weeks. Obesity increased plasma glucose and insulin and decreased irisin and FGF-21. In scWAT, this was accompanied with raised protein abundance of markers of adipocyte differentiation, i.e., C/EBP-α, C/EBP-β, and PPAR-γ, whereas brown fat-related genes, i.e., PRDM-16, AMPK/SIRT1/PGC-1α, were reduced as was UCP1 and markers of fatty acid transport, i.e., CD36 and CPT1. Exercise training increased protein expression of brown fat-related markers, i.e., PRDM-16, AMPK/SIRT1/PGC-1α, and UCP1, together with gene expression of fatty acid transport, i.e., CD36 and CPT1, but decreased markers of adipocyte differentiation, i.e., C/EBP-α, C/EBP-β, and plasma glucose. The majority of these adaptations were greater with HIIT compared to MICT. Our findings indicate that prolonged exercise training promotes the browning of white adipocytes, possibly through suppression of adipogenesis together with white to beige trans-differentiation and is dependent on the intensity of exercise.
Characterization of the histone methyltransferase PRDM9 using biochemical, biophysical and chemical biology techniques.
Koh-Stenta Xiaoying,Joy Joma,Poulsen Anders,Li Rong,Tan Yvonne,Shim Yoonjung,Min Jung-Hyun,Wu Liling,Ngo Anna,Peng Jianhe,Seetoh Wei Guang,Cao Jing,Wee John Liang Kuan,Kwek Perlyn Zekui,Hung Alvin,Lakshmanan Umayal,Flotow Horst,Guccione Ernesto,Hill Jeffrey
The Biochemical journal
PRDM proteins have emerged as important regulators of disease and developmental processes. To gain insight into the mechanistic actions of the PRDM family, we have performed comprehensive characterization of a prototype member protein, the histone methyltransferase PRDM9, using biochemical, biophysical and chemical biology techniques. In the present paper we report the first known molecular characterization of a PRDM9-methylated recombinant histone octamer and the identification of new histone substrates for the enzyme. A single C321P mutant of the PR/SET domain was demonstrated to significantly weaken PRDM9 activity. Additionally, we have optimized a robust biochemical assay amenable to high-throughput screening to facilitate the generation of small-molecule chemical probes for this protein family. The present study has provided valuable insight into the enzymology of an intrinsically active PRDM protein.
PRDM14: A Potential Target for Cancer Therapy.
Ou Mengting,Li Shun,Tang Liling
Current cancer drug targets
PRDM14 belongs to the PR domain-containing (PRDM) family. Although a precise understanding focused on the function of PRDM14 to maintain stemness and pluripotency in embryonic stem cells via epigenetic mechanisms, growing experimental evidence has been linked PRDM14 to human cancers. In adults, PRDM14 has low expression in human tissues. Aberrant PRDM14 expression is connected with various malignant histological types and solid cancers, where PRDM14 can act as a driver of oncogenic processes. Overexpression of RPDM14 enhanced cancer cells growth and reduced cancer cells sensitive to chemotherapeutic agents. Reducing the expression of PRDM14 in cancer cells can enhance the therapeutic sensitivity of drugs to cancer cells, suggesting that aberrant PRDM14 may have a carcinogenic characteristic in tumor therapy and as a new molecular target. This review summarizes the structure and oncogenic properties of PRDM14 in different malignancies and suggests that PRDM14 may be a potential therapeutic molecular target for tumor treatment.
Zinc fingers 1, 2, 5 and 6 of transcriptional regulator, PRDM4, are required for its nuclear localisation.
Tunbak Hale,Georgiou Christiana,Guan Cui,Richardson William David,Chittka Alexandra
Biochemical and biophysical research communications
PRDM4 is a member of the PRDM family of transcriptional regulators which control various aspects of cellular differentiation and proliferation. PRDM proteins exert their biological functions both in the cytosol and the nucleus of cells. All PRDM proteins are characterised by the presence of two distinct structural motifs, the PR/SET domain and the zinc finger (ZF) motifs. We previously observed that deletion of all six zinc fingers found in PRDM4 leads to its accumulation in the cytosol, whereas overexpressed full length PRDM4 is found predominantly in the nucleus. Here, we investigated the requirements for single zinc fingers in the nuclear localisation of PRDM4. We demonstrate that ZF's 1, 2, 5 and 6 contribute to the accumulation of PRDM4 in the nucleus. Their effect is additive as deleting either ZF1-2 or ZF 5-6 redistributes PRDM4 protein from being almost exclusively nuclear to cytosolic and nuclear. We investigated the potential mechanism of nuclear shuttling of PRDM4 via the importin α/β-mediated pathway and find that PRDM4 nuclear targeting is independent of α/β-mediated nuclear import.
The Multifaceted Roles of PRDM16: Adipose Biology and Beyond.
Chi Jingyi,Cohen Paul
Trends in endocrinology and metabolism: TEM
The PRDM [PRDI-BFI (positive regulatory domain I-binding factor 1) and RIZ1 (retinoblastoma protein-interacting zinc finger gene 1) homologous domain containing] protein family is involved in a spectrum of biological processes including cell fate determination and development. These proteins regulate transcription through intrinsic chromatin-modifying activity or by complexing with histone-modifying or other nuclear proteins. Studies have indicated crucial roles for PRDM16 in the determination and function of brown and beige fat as well as in hematopoiesis and cardiac development, highlighting the importance of PRDM16 in developmental processes in different tissues. More recently, PRDM16 mutations were also identified in humans. The substantial progress in understanding the mechanism underlying the action of PRDM16 in adipose biology may have relevance to other PRDM family members, and this new knowledge has the potential to be exploited for therapeutic benefit.
Critical Function of PRDM2 in the Neoplastic Growth of Testicular Germ Cell Tumors.
Di Zazzo Erika,Porcile Carola,Bartollino Silvia,Moncharmont Bruno
Testicular germ cell tumors (TGCTs) derive from primordial germ cells. Their maturation is blocked at different stages, reflecting histological tumor subtypes. A common genetic alteration in TGCT is a deletion of the chromosome 1 short arm, where the gene, belonging to the ositive egulatory domain gene () family, is located. Expression of gene is shifted in different human tumors, where the expression of the two principal protein forms coded by gene, RIZ1 and RIZ2, is frequently unbalanced. Therefore, is actually considered a candidate tumor suppressor gene in different types of cancer. Although recent studies have demonstrated that gene family members have a pivotal role during the early stages of testicular development, no information are actually available on the involvement of these genes in TGCTs. In this article we show by qRT-PCR analysis that expression level is modulated by proliferation and differentiation agents such as estradiol, whose exposure during fetal life is probably an important risk factor for TGCTs development in adulthood. Furthermore in normal and cancer germ cell lines, PRDM2 binds estradiol receptor α (ERα) and influences proliferation, survival and apoptosis, as previously reported using MCF-7 breast cancer cell line, suggesting a potential tumor-suppressor role in TGCT formation.
PR/SET Domain Family and Cancer: Novel Insights from the Cancer Genome Atlas.
Sorrentino Anna,Federico Antonio,Rienzo Monica,Gazzerro Patrizia,Bifulco Maurizio,Ciccodicola Alfredo,Casamassimi Amelia,Abbondanza Ciro
International journal of molecular sciences
The PR/SET domain gene family (PRDM) encodes 19 different transcription factors that share a subtype of the SET domain [Su(var)3-9, enhancer-of-zeste and trithorax] known as the PRDF1-RIZ (PR) homology domain. This domain, with its potential methyltransferase activity, is followed by a variable number of zinc-finger motifs, which likely mediate protein⁻protein, protein⁻RNA, or protein⁻DNA interactions. Intriguingly, almost all PRDM family members express different isoforms, which likely play opposite roles in oncogenesis. Remarkably, several studies have described alterations in most of the family members in malignancies. Here, to obtain a pan-cancer overview of the genomic and transcriptomic alterations of genes, we reanalyzed the Exome- and RNA-Seq public datasets available at The Cancer Genome Atlas portal. Overall, , , , and were the most mutated genes with pan-cancer frequencies of protein-affecting mutations higher than 1%. Moreover, we observed heterogeneity in the mutation frequencies of these genes across tumors, with cancer types also reaching a value of about 20% of mutated samples for a specific gene. Of note, mutations occurred in 50% of adrenocortical carcinoma patients and were localized in a hotspot region. These findings, together with OncodriveCLUST results, suggest it could be putatively considered a cancer driver gene in this malignancy. Finally, transcriptome analysis from RNA-Seq data of paired samples revealed that transcription of was significantly altered in several tumors. Specifically, and were largely overexpressed in many cancers whereas and were often downregulated. Some of these findings were also confirmed by real-time-PCR on primary tumors.
Family expansion and gene rearrangements contributed to the functional specialization of PRDM genes in vertebrates.
Fumasoni Irene,Meani Natalia,Rambaldi Davide,Scafetta Gaia,Alcalay Myriam,Ciccarelli Francesca D
BMC evolutionary biology
BACKGROUND:Progressive diversification of paralogs after gene expansion is essential to increase their functional specialization. However, mode and tempo of this divergence remain mostly unclear. Here we report the comparative analysis of PRDM genes, a family of putative transcriptional regulators involved in human tumorigenesis. RESULTS:Our analysis assessed that the PRDM genes originated in metazoans, expanded in vertebrates and further duplicated in primates. We experimentally showed that fast-evolving paralogs are poorly expressed, and that the most recent duplicates, such as primate-specific PRDM7, acquire tissue-specificity. PRDM7 underwent major structural rearrangements that decreased the number of encoded Zn-Fingers and modified gene splicing. Through internal duplication and activation of a non-canonical splice site (GC-AG), PRDM7 can acquire a novel intron. We also detected an alternative isoform that can retain the intron in the mature transcript and that is predominantly expressed in human melanocytes. CONCLUSION:Our findings show that (a) molecular evolution of paralogs correlates with their expression pattern; (b) gene diversification is obtained through massive genomic rearrangements; and (c) splicing modification contributes to the functional specialization of novel genes.
Prdm proto-oncogene transcription factor family expression and interaction with the Notch-Hes pathway in mouse neurogenesis.
Kinameri Emi,Inoue Takashi,Aruga Jun,Imayoshi Itaru,Kageyama Ryoichiro,Shimogori Tomomi,Moore Adrian W
BACKGROUND:Establishment and maintenance of a functional central nervous system (CNS) requires a highly orchestrated process of neural progenitor cell proliferation, cell cycle exit, and differentiation. An evolutionary conserved program consisting of Notch signalling mediated by basic Helix-Loop-Helix (bHLH) transcription factor activity is necessary for both the maintenance of neural progenitor cell character and the progression of neurogenesis; however, additional players in mammalian CNS neural specification remain largely unknown. In Drosophila we recently characterized Hamlet, a transcription factor that mediates Notch signalling and neural cell fate. METHODOLOGY/PRINCIPAL FINDINGS:Hamlet is a member of the Prdm (PRDI-BF1 and RIZ homology domain containing) proto-oncogene transcription factor family, and in this study we report that multiple genes in the Prdm family (Prdm6, 8, 12, 13 and 16) are expressed in the developing mouse CNS in a spatially and temporally restricted manner. In developing spinal cord Prdm8, 12 and 13 are expressed in precise neuronal progenitor zones suggesting that they may specify discrete neuronal subtypes. In developing telencephalon Prdm12 and 16 are expressed in the ventricular zone in a lateral to medial graded manner, and Prdm8 is expressed in a complementary domain in postmitotic neurons. In postnatal brain Prdm8 additionally shows restricted expression in cortical layers 2/3 and 4, the hippocampus, and the amygdala. To further elucidate roles of Prdm8 and 16 in the developing telencephalon we analyzed the relationship between these factors and the bHLH Hes (Hairy and enhancer of split homolog) effectors of Notch signalling. In Hes null telencephalon neural differentiation is enhanced, Prdm8 expression is upregulated, and Prdm16 expression is downregulated; conversely in utero electroporation of Hes1 into the developing telencephalon upregulates Prdm16 expression. CONCLUSIONS/SIGNIFICANCE:Our data demonstrate that Prdm genes are regulated by the Notch-Hes pathway and represent strong candidates to control neural class specification and the sequential progression of mammalian CNS neurogenesis.
Redundant roles of PRDM family members in zebrafish craniofacial development.
Ding Hai-Lei,Clouthier David E,Artinger Kristin B
Developmental dynamics : an official publication of the American Association of Anatomists
BACKGROUND:PRDM proteins are evolutionary conserved Zn-Finger transcription factors that share a characteristic protein domain organization. Previous studies have shown that prdm1a is required for the specification and differentiation of neural crest cells in the zebrafish. RESULTS:Here we examine other members of this family, specifically prdm3, 5, and 16, in the differentiation of the zebrafish craniofacial skeleton. prdm3 and prdm16 are strongly expressed in the pharyngeal arches, while prdm5 is expressed specifically in the area of the forming neurocranium. Knockdown of prdm3 and prdm16 results in a reduction in the neural crest markers dlx2a and barx1 and defects in both the viscerocranium and the neurocranium. The knockdown of prdm3 and prdm16 in combination is additive in the neurocranium, but not in the viscerocranium. Injection of sub-optimal doses of prdm1a with prdm3 or prdm16 Morpholinos together leads to more severe phenotypes in the viscerocranium and neurocranium. prdm5 mutants have defects in the neurocranium and prdm1a and prdm5 double mutants also show more severe phenotypes. CONCLUSIONS:Overall, our data reveal that prdm3, 5, and 16 are involved in the zebrafish craniofacial development and that prdm1a may interact with prdm3, 5, and 16 in the formation of the craniofacial skeleton in zebrafish.
The identification and structure of an N-terminal PR domain show that FOG1 is a member of the PRDM family of proteins.
Clifton Molly K,Westman Belinda J,Thong Sock Yue,O'Connell Mitchell R,Webster Michael W,Shepherd Nicholas E,Quinlan Kate G,Crossley Merlin,Blobel Gerd A,Mackay Joel P
FOG1 is a transcriptional regulator that acts in concert with the hematopoietic master regulator GATA1 to coordinate the differentiation of platelets and erythrocytes. Despite considerable effort, however, the mechanisms through which FOG1 regulates gene expression are only partially understood. Here we report the discovery of a previously unrecognized domain in FOG1: a PR (PRD-BF1 and RIZ) domain that is distantly related in sequence to the SET domains that are found in many histone methyltransferases. We have used NMR spectroscopy to determine the solution structure of this domain, revealing that the domain shares close structural similarity with SET domains. Titration with S-adenosyl-L-homocysteine, the cofactor product synonymous with SET domain methyltransferase activity, indicated that the FOG PR domain is not, however, likely to function as a methyltransferase in the same fashion. We also sought to define the function of this domain using both pulldown experiments and gel shift assays. However, neither pulldowns from mammalian nuclear extracts nor yeast two-hybrid assays reproducibly revealed binding partners, and we were unable to detect nucleic-acid-binding activity in this domain using our high-diversity Pentaprobe oligonucleotides. Overall, our data demonstrate that FOG1 is a member of the PRDM (PR domain containing proteins, with zinc fingers) family of transcriptional regulators. The function of many PR domains, however, remains somewhat enigmatic for the time being.
The Prdm family: expanding roles in stem cells and development.
Hohenauer Tobias,Moore Adrian W
Development (Cambridge, England)
Members of the Prdm family are characterized by an N-terminal PR domain that is related to the SET methyltransferase domain, and multiple zinc fingers that mediate sequence-specific DNA binding and protein-protein interactions. Prdm factors either act as direct histone methyltransferases or recruit a suite of histone-modifying enzymes to target promoters. In this way, they function in many developmental contexts to drive and maintain cell state transitions and to modify the activity of developmental signalling pathways. Here, we provide an overview of the structure and function of Prdm family members and discuss the roles played by these proteins in stem cells and throughout development.
Genetic basis for primordial germ cells specification in mouse and human: Conserved and divergent roles of PRDM and SOX transcription factors.
Sybirna Anastasiya,Wong Frederick C K,Surani M Azim
Current topics in developmental biology
Primordial germ cells (PGCs) are embryonic precursors of sperm and egg that pass on genetic and epigenetic information from one generation to the next. In mammals, they are induced from a subset of cells in peri-implantation epiblast by BMP signaling from the surrounding tissues. PGCs then initiate a unique developmental program that involves comprehensive epigenetic resetting and repression of somatic genes. This is orchestrated by a set of signaling molecules and transcription factors that promote germ cell identity. Here we review significant findings on mammalian PGC biology, in particular, the genetic basis for PGC specification in mice and human, which has revealed an evolutionary divergence between the two species. We discuss the importance and potential basis for these differences and focus on several examples to illustrate the conserved and divergent roles of critical transcription factors in mouse and human germline.
PRDM proteins: important players in differentiation and disease.
Fog Cathrine K,Galli Giorgio G,Lund Anders H
BioEssays : news and reviews in molecular, cellular and developmental biology
The PRDM family has recently spawned considerable interest as it has been implicated in fundamental aspects of cellular differentiation and exhibits expanding ties to human diseases. The PRDMs belong to the SET domain family of histone methyltransferases, however, enzymatic activity has been determined for only few PRDMs suggesting that they act by recruiting co-factors or, more speculatively, confer methylation of non-histone targets. Several PRDM family members are deregulated in human diseases, most prominently in hematological malignancies and solid cancers, where they can act as both tumor suppressors or drivers of oncogenic processes. The molecular mechanisms have been delineated for only few PRDMs and little is known about functional redundancy within the family. Future studies should identify target genes of PRDM proteins and the protein complexes in which PRDM proteins reside to provide a more comprehensive understanding of the biological and biochemical functions of this important protein family.
PRDM Proteins: Molecular Mechanisms in Signal Transduction and Transcriptional Regulation.
Di Zazzo Erika,De Rosa Caterina,Abbondanza Ciro,Moncharmont Bruno
PRDM (PRDI-BF1 and RIZ homology domain containing) protein family members are characterized by the presence of a PR domain and a variable number of Zn-finger repeats. Experimental evidence has shown that the PRDM proteins play an important role in gene expression regulation, modifying the chromatin structure either directly, through the intrinsic methyltransferase activity, or indirectly through the recruitment of chromatin remodeling complexes. PRDM proteins have a dual action: they mediate the effect induced by different cell signals like steroid hormones and control the expression of growth factors. PRDM proteins therefore have a pivotal role in the transduction of signals that control cell proliferation and differentiation and consequently neoplastic transformation. In this review, we describe pathways in which PRDM proteins are involved and the molecular mechanism of their transcriptional regulation.
Histone Methyltransferase mRNA Levels Increase in Response to Curative Hormone Treatment for Cryptorchidism-Dependent Male Infertility.
Hadziselimovic Faruk,Cathomas Gieri,Verkauskas Gilvydas,Dasevicius Darius,Stadler Michael B
There is a correlation between cryptorchidism and an increased risk of testicular cancer and infertility. During orchidopexy, testicular biopsies are performed to confirm the presence of type A dark (Ad) spermatogonia, which are a marker for low infertility risk (LIR). The Ad spermatogonia are absent in high infertility risk (HIR) patients, who are treated with a gonadotropin-releasing hormone agonist (GnRHa) to significantly lower the risk of infertility. Despite its prevalence, little is known about the molecular events involved in cryptorchidism. Previously, we compared the transcriptomes of LIR versus HIR patients treated with and without hormones. Here, we interpreted data regarding members of the positive regulatory domain-containing () family; some of which encoded histone methyltransferases that are important for reproduction. We found there were lower levels of , , , , and mRNA in the testes of HIR patients compared with LIR patients, and that , , and were significantly induced after GnRHa treatment. Furthermore, we observed protein staining in the cytoplasm of germ cells in the testes from LIR and HIR patients, indicating that the mRNA and protein levels corresponded. This result indicated that the curative hormonal therapy for cryptorchidism involved conserved chromatin modification enzymes.
An emerging role for prdm family genes in dorsoventral patterning of the vertebrate nervous system.
Zannino Denise A,Sagerström Charles G
The embryonic vertebrate neural tube is divided along its dorsoventral (DV) axis into eleven molecularly discrete progenitor domains. Each of these domains gives rise to distinct neuronal cell types; the ventral-most six domains contribute to motor circuits, while the five dorsal domains contribute to sensory circuits. Following the initial neurogenesis step, these domains also generate glial cell types-either astrocytes or oligodendrocytes. This DV pattern is initiated by two morphogens-Sonic Hedgehog released from notochord and floor plate and Bone Morphogenetic Protein produced in the roof plate-that act in concentration gradients to induce expression of genes along the DV axis. Subsequently, these DV-restricted genes cooperate to define progenitor domains and to control neuronal cell fate specification and differentiation in each domain. Many genes involved in this process have been identified, but significant gaps remain in our understanding of the underlying genetic program. Here we review recent work identifying members of the Prdm gene family as novel regulators of DV patterning in the neural tube. Many Prdm proteins regulate transcription by controlling histone modifications (either via intrinsic histone methyltransferase activity, or by recruiting histone modifying enzymes). Prdm genes are expressed in spatially restricted domains along the DV axis of the neural tube and play important roles in the specification of progenitor domains, as well as in the subsequent differentiation of motor neurons and various types of interneurons. Strikingly, Prdm proteins appear to function by binding to, and modulating the activity of, other transcription factors (particularly bHLH proteins). The identity of key transcription factors in DV patterning of the neural tube has been elucidated previously (e.g. the nkx, bHLH and pax families), but it now appears that an additional family is also required and that it acts in a potentially novel manner.
The methylation profiles of PRDM promoters in non-small cell lung cancer.
Tan Shuang-Xiang,Hu Rui-Cheng,Xia Qian,Tan Yong-Li,Liu Jing-Jing,Gan Gui-Xiang,Wang Li-le
OncoTargets and therapy
BACKGROUND:Non-small cell lung cancer (NSCLC) is one of the leading malignant tumors worldwide. Aberrant gene promoter methylation contributes to NSCLC, and PRDM is a tumor suppressor gene family that possesses histone methyltransferase activity. This study aimed to investigate whether aberrant methylation of PRDM promoter is involved in NSCLC. MATERIALS AND METHODS:Primary tumor tissues, adjacent nontumorous tissues, and distant lung tissues were collected from 75 NSCLC patients including 52 lung squamous cell carcinoma (LSCC) patients and 23 lung adenocarcinoma patients. The expression of PRDMs was detected by polymerase chain reaction (PCR), Western blot, and immunohistochemical analysis. The methylation of PRDM promoters was detected by methylation-specific PCR. The correlation of methylation and expression of PRDMs with clinicopathological characteristics of patients were analyzed. RESULTS:mRNA expression of , , and was low or absent in tumor tissues compared to distant lung tissues. The methylation frequencies of , , and in tumor tissues were significantly higher than those in distal lung tissues. In LSCC patients, methylation of and was correlated with smoking status and methylation of PRDM5 was correlated with tumor differentiation. CONCLUSION:The expression of , , and is low or absent in NSCLC, and this is mainly due to gene promoter methylation. Smoking may be an important cause of and methylation in NSCLC.
TRPV1 activation counters diet-induced obesity through sirtuin-1 activation and PRDM-16 deacetylation in brown adipose tissue.
Baskaran P,Krishnan V,Fettel K,Gao P,Zhu Z,Ren J,Thyagarajan B
International journal of obesity (2005)
BACKGROUND/OBJECTIVE:An imbalance between energy intake and expenditure leads to obesity. Increasing metabolism and thermogenesis in brown adipose tissue (BAT) can help in overcoming obesity. Here, we investigated the effect of activation of transient receptor potential vanilloid subfamily 1 (TRPV1) in the upregulation of thermogenic proteins in BAT to counter diet-induced obesity. SUBJECTS/METHODS:We investigated the effect of dietary supplementation of capsaicin (CAP) (TRPV1 agonist) on the expression of metabolically important thermogenic proteins in BAT of wild-type and TRPV1 mice that received either a normal chow or high-fat (±CAP; TRPV1 activator) diet by immunoblotting. We measured the metabolic activity, respiratory quotient and BAT lipolysis. RESULTS:CAP antagonized high-fat diet (HFD)-induced obesity without decreasing energy intake in mice. HFD suppressed TRPV1 expression and activity in BAT and CAP countered this effect. HFD-feeding caused glucose intolerance, hypercholesterolemia and decreased the plasma concentration of glucagon-like peptide-1 and CAP countered these effects. HFD suppressed the expression of metabolically important thermogenic genes, ucp-1, bmp8b, sirtuin-1 (SIRT-1), PPARγ coactivator 1α and PR domain containing zinc finger protein 16 (prdm-16) in BAT and CAP prevented this effect. CAP increased the phosphorylation of SIRT-1 and induced an interaction between peroxisome proliferator activated receptor gamma (PPARγ) with PRDM-16. Further, CAP treatment, in vitro, decreased the acetylation of PRDM-16, which was antagonized by inhibition of TRPV1 by capsazepine, chelation of intracellular Ca by cell permeable BAPTA-AM or the inhibition of SIRT-1 by EX527. Further, CAP supplementation, post HFD, promoted weight loss and enhanced the respiratory exchange ratio. CAP did not have any effect in TRPV1 mice. CONCLUSIONS:Our data show that activation of TRPV1 in BAT enhances the expression of SIRT-1, which facilitates the deacetylation and interaction of PPARγ and PRDM-16. These data suggest that TRPV1 activation is a novel strategy to counter diet-induced obesity by enhancing metabolism and energy expenditure.
Multifaceted Role of PRDM Proteins in Human Cancer.
Casamassimi Amelia,Rienzo Monica,Di Zazzo Erika,Sorrentino Anna,Fiore Donatella,Proto Maria Chiara,Moncharmont Bruno,Gazzerro Patrizia,Bifulco Maurizio,Abbondanza Ciro
International journal of molecular sciences
The PR/SET domain family (PRDM) comprise a family of genes whose protein products share a conserved N-terminal PR [PRDI-BF1 (positive regulatory domain I-binding factor 1) and RIZ1 (retinoblastoma protein-interacting zinc finger gene 1)] homologous domain structurally and functionally similar to the catalytic SET [Su(var)3-9, enhancer-of-zeste and trithorax] domain of histone methyltransferases (HMTs). These genes are involved in epigenetic regulation of gene expression through their intrinsic HMTase activity or via interactions with other chromatin modifying enzymes. In this way they control a broad spectrum of biological processes, including proliferation and differentiation control, cell cycle progression, and maintenance of immune cell homeostasis. In cancer, tumor-specific dysfunctions of genes alter their expression by genetic and/or epigenetic modifications. A common characteristic of most genes is to encode for two main molecular variants with or without the PR domain. They are generated by either alternative splicing or alternative use of different promoters and play opposite roles, particularly in cancer where their imbalance can be often observed. In this scenario, PRDM proteins are involved in cancer onset, invasion, and metastasis and their altered expression is related to poor prognosis and clinical outcome. These functions strongly suggest their potential use in cancer management as diagnostic or prognostic tools and as new targets of therapeutic intervention.
Spatiotemporal expression of Prdm genes during Xenopus development.
Eguchi Rieko,Yoshigai Emi,Koga Takamasa,Kuhara Satoru,Tashiro Kosuke
Epigenetic regulation is known to be important in embryonic development, cell differentiation and regulation of cancer cells. Molecular mechanisms of epigenetic modification have DNA methylation and histone tail modification such as acetylation, phosphorylation and ubiquitination. Until now, many kinds of enzymes that modify histone tail with various functional groups have been reported and regulate the epigenetic state of genes. Among them, Prdm genes were identified as histone methyltransferase. Prdm genes are characterized by an N-terminal PR/SET domain and C-terminal some zinc finger domains and therefore they are considered to have both DNA-binding ability and methylation activity. Among vertebrate, fifteen members are estimated to belong to Prdm genes family. Even though Prdm genes are thought to play important roles for cell fate determination and cell differentiation, there is an incomplete understanding of their expression and functions in early development. Here, we report that Prdm genes exhibit dynamic expression pattern in Xenopus embryogenesis. By whole mount in situ hybridization analysis, we show that Prdm genes are expressed in spatially localized manners in embryo and all of Prdm genes are expressed in neural cells in developing central nervous systems. Our study suggests that Prdm genes may be new candidates to function in neural cell differentiation.
Evolution of Prdm Genes in Animals: Insights from Comparative Genomics.
Vervoort Michel,Meulemeester David,Béhague Julien,Kerner Pierre
Molecular biology and evolution
Prdm genes encode transcription factors with a subtype of SET domain known as the PRDF1-RIZ (PR) homology domain and a variable number of zinc finger motifs. These genes are involved in a wide variety of functions during animal development. As most Prdm genes have been studied in vertebrates, especially in mice, little is known about the evolution of this gene family. We searched for Prdm genes in the fully sequenced genomes of 93 different species representative of all the main metazoan lineages. A total of 976 Prdm genes were identified in these species. The number of Prdm genes per species ranges from 2 to 19. To better understand how the Prdm gene family has evolved in metazoans, we performed phylogenetic analyses using this large set of identified Prdm genes. These analyses allowed us to define 14 different subfamilies of Prdm genes and to establish, through ancestral state reconstruction, that 11 of them are ancestral to bilaterian animals. Three additional subfamilies were acquired during early vertebrate evolution (Prdm5, Prdm11, and Prdm17). Several gene duplication and gene loss events were identified and mapped onto the metazoan phylogenetic tree. By studying a large number of nonmetazoan genomes, we confirmed that Prdm genes likely constitute a metazoan-specific gene family. Our data also suggest that Prdm genes originated before the diversification of animals through the association of a single ancestral SET domain encoding gene with one or several zinc finger encoding genes.
Identification of Prdm genes in human corneal endothelium.
Rolev Kostadin,O'Donovan Dominic G,Georgiou Christiana,Rajan Madhavan S,Chittka Alexandra
Experimental eye research
Corneal endothelial cells (CECs) are essential for maintaining corneal stromal hydration and ensuring its transparency, which is necessary for normal vision. Dysfunction of CECs leads to stromal decompensation, loss of transparency and corneal blindness. Corneal endothelium has low proliferative potential compared to surface epithelial cells leading to poor regeneration of CEC following injury. Additionally, the tissue exhibits age related decline in endothelial cell density with re-organisation of the cell layer, but no regeneration. The mechanisms which control proliferation and differentiation of neural crest derived CEC progenitors are yet to be clearly elucidated. Prdm (Positive regulatory domain) family of transcriptional regulators and chromatin modifiers are important for driving differentiation of a variety of cellular types. Many Prdm proteins are expressed in specific precursor cell populations and are necessary for their progression to a fully differentiated phenotype. In the present work, we sought to identify members of the Prdm gene family which are specifically expressed in human (h) CECs with a view to begin addressing their potential roles in CEC biology, focussing especially on Prdm 4 and 5 genes. By performing semi-quantitative reverse transcription coupled to PCR amplification we found that in addition to Prdm4 and Prdm5, Prdm2 and Prdm10 genes are expressed in hCECs. We further found that cultured primary hCECs or immortalised HCEC-12 cells express all of the Prdm genes found in CECs, but also express additional Prdm transcripts. This difference is most pronounced between Prdm gene expression patterns of CECs isolated from healthy human corneas and immortalised HCEC-12 cells. We further investigated Prdm 4 and Prdm 5 protein expression in cultured primary hCECs and HCEC-12 cells as well as in a human cadaveric whole cornea. Both Prdm 4 and Prdm 5 are expressed in human corneal endothelium, primary hCECs and in HCECs-12 cells, characterised by expression of the Na/K-ATPase. We observed that both proteins exhibit cytosolic (intracellular, but non-nuclear and distinct from extracellular fluid) as well as nuclear localisation within the endothelial layer, with Prdm 5 being more concentrated in the nuclei of the endothelial cells than Prdm 4. Thus, our work identifies novel Prdm genes specifically expressed in corneal endothelial cells which may be important in the control of CEC differentiation and proliferation.