DC32, a Dihydroartemisinin Derivative, Ameliorates Collagen-Induced Arthritis Through an Nrf2-p62-Keap1 Feedback Loop.
Fan Menglin,Li Yanan,Yao Chunhua,Liu Xiufeng,Liu Jihua,Yu Boyang
Frontiers in immunology
Artemisinins have been reported to have diverse functions, such as antimalaria, anticancer, anti-inflammation, and immunoregulation activities. DC32 [(9α,12α-dihydroartemisinyl) bis(2'-chlorocinnmate)], a dihydroartemisinin derivative possessing potent immunosuppressive properties, was synthesized in our previous study. Collagen-induced arthritis (CIA) in DBA/1 mice and inflammatory model in NIH-3T3 cells were established to evaluate the effect of DC32 on RA and discover the underlying mechanisms. The results showed that DC32 could markedly alleviate footpad inflammation, reduce cartilage degradation, activate the Nrf2/HO-1 signaling pathway, and increase the transcription of p62 in DBA/1 mice with CIA. Further mechanistic exploration with NIH-3T3 cells indicated that DC32 could increase the transcription, expression, and nuclear translocation of Nrf2. In addition, DC32 promoted degradation of Keap1 protein and upregulated HO-1 and p62 expression. Furthermore, the effect of DC32 on Keap1 degradation could be prevented by p62 knockdown using siRNA. Administration of DC32 could inhibit the activation of Akt/mTOR and ERK, and pretreatment of NIH-3T3 cells with the autophagy inhibitor 3-methyladenine (3-MA) attenuated the degradation of Keap1 induced by DC32. These results suggest that DC32 inhibits the degradation of Nrf2 by promoting p62-mediated selective autophagy and that p62 upregulation contributed to a positive feedback loop for persistent activation of Nrf2. In summary, our present study demonstrated that DC32 significantly suppressed rheumatoid arthritis (RA) via the Nrf2-p62-Keap1 feedback loop by increasing the mRNA and protein levels of Nrf2 and inducing p62 expression. These findings provide new mechanisms for artemisinins in RA treatment and a potential strategy for discovering antirheumatic drugs.
10.3389/fimmu.2018.02762
Ginsenoside Rg1 prevents bone marrow mesenchymal stem cell senescence via NRF2 and PI3K/Akt signaling.
Free radical biology & medicine
Senescence limits the characteristics and functionality of mesenchymal stem cells (MSCs), thereby severely restricting their application in tissue engineering. Here, we investigated ways to prevent MSCs from entering a state of senescence. We found that Rg1, an extract of natural ginseng, can reduce the expression of senescence markers in cultured cells in vitro and in various tissues in vivo. Simultaneously, ginsenoside Rg1 improved the antioxidant capacity of cells, and the senescence-inhibiting and antioxidant effect of Rg1 were associated with the activation of the nuclear factor E2-related factor 2 (NRF2) signaling pathway. Furthermore, Rg1 may activate the NRF2 pathway by increasing the interaction between P62 and KEAP1through P62 upregulation and AKT activation. Taken together, our findings indicate that Rg1 prevents cell senescence via NRF2 and AKT, and activation of AKT or NRF2 may thus represent therapeutic targets for preventing cell senescence.
10.1016/j.freeradbiomed.2021.08.007
Derived Astaxanthin Is a Potential Neuroprotective Agent against Optic Nerve Ischemia.
Lin Wei-Ning,Kapupara Kishan,Wen Yao-Tseng,Chen Yi-Hsun,Pan I-Hong,Tsai Rong-Kung
Marine drugs
Astaxanthin, a xanthophyll belonging to the family of carotenoids, is a potent antioxidant. However, much less is known about its protective effects on the oxidative stress of ischemic optic nerve. We hypothesized that astaxanthin treatment could protect retinal ganglion cells (RGCs) from death via anti-oxidative and anti-apoptotic responses. Adult male Wistar rats were fed astaxanthin (100 mg/kg/day) by daily gavage for seven consecutive days, either before or after inducing oxidative stress in the retina by photodynamic treatment. The visual function, RGC apoptosis, macrophage infiltration in the optic nerve, expression of p-Akt, p-mTOR, SGK1, pS6K, Nrf2, p62, TNFα, Il1β in retinas were investigated. The visual function and the RGC densities were significantly higher in both pre- and post-treatment groups. The numbers of apoptotic RGCs and extrinsic macrophage infiltration in the optic nerve were significantly decreased in both astaxanthin-treated groups. Furthermore, pre- and post-treatment of astaxanthin showed a higher expression of p-Akt, p-mTOR, Nrf2 and superoxide dismutase activity, and a lower expression of cleaved caspase-3, suggesting anti-apoptotic and anti-oxidative roles. Our findings indicate that astaxanthin can preserve visual function and reduce RGC apoptosis after ischemic insults. Including astaxanthin in daily diet as a supplement may be beneficiary for ischemic optic neuropathy.
10.3390/md18020085
A detrimental role of NLRP6 in host iron metabolism during Salmonella infection.
Redox biology
Maintaining host iron homeostasis is an essential component of nutritional immunity responsible for sequestrating iron from pathogens and controlling infection. Nucleotide-oligomerization domain-like receptors (NLRs) contribute to cytoplasmic sensing and antimicrobial response orchestration. However, it remains unknown whether and how NLRs may regulate host iron metabolism, an important component of nutritional immunity. Here, we demonstrated that NLRP6, a member of the NLR family, has an unconventional role in regulating host iron metabolism that perturbs host resistance to bacterial infection. NLRP6 deficiency is advantageous for maintaining cellular iron homeostasis in both macrophages and enterocytes through increasing the unique iron exporter ferroportin-mediated iron efflux in a nuclear factor erythroid-derived 2-related factor 2 (NRF2)-dependent manner. Additional studies uncovered a novel mechanism underlying NRF2 regulation and operating through NLRP6/AKT interaction and that causes a decrease in AKT phosphorylation, which in turn reduces NRF2 nuclear translocation. In the absence of NLRP6, increased AKT activation promotes NRF2/KEAP1 dissociation via increasing mTOR-mediated p62 phosphorylation and downregulates KEAP1 transcription by promoting FOXO3A phosphorylation. Together, our observations provide new insights into the mechanism of nutritional immunity by revealing a novel function of NLRP6 in regulating iron metabolism, and suggest NLRP6 as a therapeutic target for limiting bacterial iron acquisition.
10.1016/j.redox.2021.102217
Chronic lung inflammation and pulmonary fibrosis after multiple intranasal instillation of PM in mice.
Xu Mengmeng,Wang Xiaohui,Xu Lu,Zhang Hai,Li Chenfei,Liu Qi,Chen Yuqing,Chung Kian Fan,Adcock Ian M,Li Feng
Environmental toxicology
Fine particulate matter (PM ) is an important component of air pollution and can induce lung inflammation and oxidative stress. We hypothesized that PM could play a role in the induction of pulmonary fibrosis. We examined whether multiple intranasal instillation of PM can induce pulmonary fibrosis in the mouse, and also investigated the underlying pro-fibrotic signaling pathways. C57/BL6 mice were intranasally instilled with 50 μl of PM suspension (7.8 μg/g body weight) or PBS three times a week over 3 weeks, 6 weeks or 9 weeks. To observe the recovery of pulmonary fibrosis after the termination of PM exposure, 9 week-PM instilled mice were also studied at 3 weeks after termination of instillation. There were significant decreases in total lung capacity (TLC) and compliance (Cchord) in the 9-week PM -instilled mice, while there were increased histological fibrosis scores with enhanced type I collagen and hydroxyproline deposition, increased mitochondrial ROS levels and NOX activity, decreased total SOD and GSH levels, accompanied by decreased mitochondrial number and aberrant mitochondrial morphology (swelling, vacuolization, cristal disruption, reduced matrix density) in PM -instilled mice. Multiple PM instillation resulted in increased expression of TGFβ1, increases of N-Cadherin and Vimentin and a decrease of E-Cadherin. It also led to decreases in OPA1 and MFN2, and increases in Parkin, SQSTM1/p62, the ratio of light china (LC) 3B II to LC3B I, PI3k/Akt phosphorylation, and NLRP3 expression. Intranasal instillation of PM for 9 weeks induced lung inflammation and pulmonary fibrosis, which was linked with aberrant epithelial-mesenchymal transition, oxidative stress, mitochondrial damage and mitophagy, as well as activation of TGFβ1-PI3K/Akt, TGFβ1- NOX and TGFβ1-NLRP3 pathways.
10.1002/tox.23140
The Antioxidant from Ethanolic Extract of Fruits Activates Phosphatase and Tensin Homolog In Vitro and In Vivo: A New Insight on Its Antileukemic Effect.
Wang Kuan-Chih,Liu Yi-Chang,El-Shazly Mohamed,Shih Shou-Ping,Du Ying-Chi,Hsu Yu-Ming,Lin Hung-Yu,Chen Yu-Cheng,Wu Yang-Chang,Yang Shyh-Chyun,Lu Mei-Chin
International journal of molecular sciences
Tratt is a Chinese herbal remedy that is used in the treatment of diarrhea, burns, rheumatoid arthritis, and hemorrhage. Despite its use in Asian folk medicine, there are limited reports on the biological activity of fruits. This study focused on the investigation of the antitumor effect of the antioxidative ethanolic extract of fruits (RCE) along with its underlying mechanism of action. RCE showed a potent cytotoxic effect against Sup-T1 and Molt-4 lymphoblastic leukemia cells. In the xenograft animal model, the tumor size was significantly reduced to about 59.42% in the RCE-treated group in comparison with the control group. The use of RCE (37.5, 75, or 150 μg/mL) triggered apoptosis by 26.52-83.49%, disrupted mitochondrial membrane potential (MMP) by 10.44-58.60%, and promoted calcium release by 1.29-, 1.44-, and 1.71-fold compared with the control group. The extract induced redox oxygen species (ROS) generation through the elimination of Nrf2/Keap1/P62-mediated oxidative stress response. The loss of phosphatase and tensin homolog (PTEN) activation by RCE impaired PI3K/Akt/Foxo and Jak/Stat activation pathways, which contributed to tumorigenesis. These multiple targets of against hematologic cancer cells suggested its potential application as an antileukemic dietary supplement.
10.3390/ijms20081935
Ulinastatin attenuates LPS-induced inflammation in mouse macrophage RAW264.7 cells by inhibiting the JNK/NF-κB signaling pathway and activating the PI3K/Akt/Nrf2 pathway.
Li Si-Tong,Dai Qi,Zhang Shu-Xian,Liu Ya-Jun,Yu Qiu-Qiong,Tan Fei,Lu Shu-Hong,Wang Quan,Chen Jian-Wen,Huang He-Qing,Liu Pei-Qing,Li Min
Acta pharmacologica Sinica
Ulinastatin (UTI) is a broad-spectrum serine protease inhibitor isolated and purified from human urine with strong anti-inflammatory and cytoprotective actions, which is widely used for the treatment of various diseases, such as pancreatitis and sepsis. Although the therapeutic effects of UTI are reported to be associated with a variety of mechanisms, the signaling pathways mediating the anti-inflammatory action of UTI remain to be elucidated. In the present study we carried out a systematic study on the anti-inflammatory and anti-oxidative mechanisms of UTI and their relationships in LPS-treated RAW264.7 cells. Pretreatment with UTI (1000 and 5000 U/mL) dose-dependently decreased the mRNA levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, iNOS) and upregulated anti-inflammatory cytokines (IL-10 and TGF-β1) in LPS-treated RAW264.7 cells. UTI pretreatment significantly inhibited the nuclear translocation of NF-κB by preventing the degradation of IκB-α. UTI pretreatment only markedly inhibited the phosphorylation of JNK at Thr183, but it did not affect the phosphorylation of JNK at Tyr185, ERK-1/2 and p38 MAPK; JNK was found to function upstream of the IκB-α/NF-κB signaling pathway. Furthermore, UTI pretreatment significantly suppressed LPS-induced ROS production by activating PI3K/Akt pathways and the nuclear translocation of Nrf2 via promotion of p62-associated Keap1 degradation. However, JNK was not involved in mediating the anti-oxidative stress effects of UTI. In summary, this study shows that UTI exerts both anti-inflammatory and anti-oxidative effects by targeting the JNK/NF-κB and PI3K/Akt/Nrf2 pathways.
10.1038/aps.2017.143
IGF2 mRNA binding protein p62/IMP2-2 in hepatocellular carcinoma: antiapoptotic action is independent of IGF2/PI3K signaling.
Kessler Sonja M,Pokorny Juliane,Zimmer Vincent,Laggai Stephan,Lammert Frank,Bohle Rainer M,Kiemer Alexandra K
American journal of physiology. Gastrointestinal and liver physiology
The insulin-like growth factor II (IGF2) mRNA binding protein (IMP) p62/IMP2-2, originally isolated from a hepatocellular carcinoma (HCC) patient, induces a steatotic phenotype when overexpressed in mouse livers. Still, p62 transgenic livers do not show liver cell damage but exhibit a pronounced induction of Igf2 and activation of the downstream survival kinase AKT. The aim of this study was to investigate the relation between p62 and IGF2 expression in the human system and to study potential antiapoptotic actions of p62. p62 and IGF2 mRNA levels were assessed by real-time RT-PCR. For knockdown and overexpression experiments, human hepatoma HepG2 and PLC/PRF/5 cells were transfected with siRNA or plasmid DNA. Phosphorylated AKT and ERK1/2 were analyzed by Western blot. Investigations of 32 human HCC tissues showed a strong correlation between p62 and IGF2 expression. Of note, p62 expression was increased markedly in patients with poor outcome. In hepatoma cells overexpression of p62 lowered levels of doxorubicin-induced caspase-3-like activity. Vice versa, knockdown of p62 resulted in increased doxorubicin-induced apoptosis. However, neither PI3K inhibitors nor a neutralizing IGF2 antibody showed any effects. Western blot analysis revealed increased levels of phosphorylated ERK1/2 in hepatoma cells overexpressing p62 and decreased levels in p62 knockdown experiments. When p62-overexpressing cells were treated with ERK1/2 inhibitors, the apoptosis-protecting effect of p62 was completely abrogated. Our data demonstrate that p62 exerts IGF2-independent antiapoptotic action, which is facilitated via phosphorylation of ERK1/2. Furthermore, p62 might serve as a new prognostic marker in HCC.
10.1152/ajpgi.00005.2012
TPI1 activates the PI3K/AKT/mTOR signaling pathway to induce breast cancer progression by stabilizing CDCA5.
Journal of translational medicine
BACKGROUND:Triosephosphate isomerase 1 (TPI1), as a key glycolytic enzyme, is upregulated in multiple cancers. However, expression profile and regulatory mechanism of TPI1 in breast cancer (BRCA) remain mysterious. METHODS:Western blotting and immunohistochemistry (IHC) assays were used to investigate the expression of TPI1 in BRCA specimens and cell lines. TPI1 correlation with the clinicopathological characteristics and prognosis of 362 BRCA patients was analyzed using a tissue microarray. Overexpression and knockdown function experiments in cells and mice models were performed to elucidate the function and mechanisms of TPI1-induced BRCA progression. Related molecular mechanisms were clarified using co-IP, IF, mass spectrometric analysis, and ubiquitination assay. RESULTS:We have found TPI1 is highly expressed in BRCA tissue and cell lines, acting as an independent indicator for prognosis in BRCA patients. TPI1 promotes BRCA cell glycolysis, proliferation and metastasis in vitro and in vivo. Mechanistically, TPI1 activates phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway to regulate epithelial-mesenchymal transformation (EMT) and aerobic glycolysis, which is positively mediated by cell division cycle associated 5 (CDCA5). Moreover, TPI1 interacts with sequestosome-1 (SQSTM1)/P62, and P62 decreases the protein expression of TPI1 by promoting its ubiquitination in MDA-MB-231 cells. CONCLUSIONS:TPI1 promotes BRCA progression by stabilizing CDCA5, which then activates the PI3K/AKT/mTOR pathway. P62 promotes ubiquitin-dependent proteasome degradation of TPI1. Collectively, TPI1 promotes tumor development and progression, which may serve as a therapeutic target for BRCA.
10.1186/s12967-022-03370-2
Sequestosome 1/p62 facilitates HER2-induced mammary tumorigenesis through multiple signaling pathways.
Cai-McRae X,Zhong H,Karantza V
Oncogene
Previous studies have shown that increased levels of the adaptor protein Sequestosome 1/p62 are observed in human breast cancers and significantly correlate with HER2 overexpression. However, the role of p62 in the pathophysiology of HER2-induced mammary tumorigenesis has not yet been investigated. In this study, we report that p62 facilitates HER2-mediated cell survival in both two-dimensional and three-dimensional cell culture and that HER2-induced cellular transformation requires p62, as well as NRF2, which is known to become stabilized by its release from Kelch-like ECH-associated protein 1 (KEAP1) via p62-KEAP1 interaction. In agreement with these results, genetic ablation of p62 delays HER2-induced mammary tumorigenesis in tumor cell allografts in nude mice, and in MMTV-Neu transgenic mice. We also report that ablation of p62 impairs AKT and β-catenin activation in association with PTEN (phosphatase and tensin homolog deleted on chromosome ten) accumulation, both in vitro and in vivo. Further in vivo studies suggest that loss of p62 also impairs NF-κB and NRF2 activation. Collectively, our results provide compelling evidence that p62 contributes to HER2-induced mammary tumorigenesis through multiple signaling pathways, including the PTEN/phosphoinositide-3-kinase/AKT axis, WNT/β-catenin signaling, the NF-κB pathway and the NRF2-KEAP1 axis, and offer novel insights into the potential role of p62 in the regulation of the tumor suppressor PTEN.
10.1038/onc.2014.244
p62 protects SH-SY5Y neuroblastoma cells against H2O2-induced injury through the PDK1/Akt pathway.
Heo Seong Ryong,Han Ah Mi,Kwon Yunhee Kim,Joung Insil
Neuroscience letters
The p62 protein has been identified as a major component of the protein aggregations associated with neurodegenerative disease. Oxidative insult has also been identified as a principal cause of neurodegenerative disease. Thus, in the present study, we investigated the potential role of p62 in oxidative stress-induced cell death in SH-SY5Y human neuroblastoma cells. The results indicated that H(2)O(2) treatment induced p62 expression in SH-SY5Y cells. In addition, p62 showed neuroprotective effects against H(2)O(2)-induced cell death in differentiated SH-SY5Y cells. p62 expression prolonged Akt phosphorylation during the later stages of H(2)O(2)-induced cell death. Furthermore, coexpression of p62 and wild-type PDK1, the upstream kinase of Akt, further increased Akt phosphorylation and cell viability, whereas the expression of kinase-defective PDK1 reversed the cytoprotective effects of p62 under oxidative stress. Overexpression of p62 led to the dissociation of PDK1 from the 14-3-3theta protein, which is thought to be a negative regulator of PDK1 kinase activity. These findings suggest a mechanism that involves the p62-mediated modulation of the interaction between signaling molecules and results in cell survival.
10.1016/j.neulet.2008.11.011