MicroRNA-9 Inhibits NLRP3 Inflammasome Activation in Human Atherosclerosis Inflammation Cell Models through the JAK1/STAT Signaling Pathway.
Wang Yue,Han Zhihua,Fan Yuqi,Zhang Junfeng,Chen Kan,Gao Lin,Zeng Huasu,Cao Jiatian,Wang Changqian
Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology
BACKGROUND/AIMS:MicroRNA-9 (miR-9) is involved in inflammatory reaction in atherosclerosis; however, its function and regulatory mechanisms remain unclear. We aimed to uncover the exact roles of miR-9 and downstream signaling pathways using in vitro human atherosclerosis models. METHODS:We used oxidized low-density lipoprotein (oxLDL)-stimulated human THP-1 derived macrophages, oxLDL-stimulated human primary peripheral blood monocytes and lipopolysaccharides (LPS) or Alum-stimulated human THP-1 derived macrophages as in vitro atherosclerosis inflammation models. Transient transfection of over-expression vectors, small interference RNAs (siRNAs) or antisense oligonucleotides was used to regulate intracellular protein or miR-9 levels. Cell responses and signal transduction were detected by multiple assays including Western blotting, enzyme-linked immunosorbent assay (ELISA) and luciferase reporter assay. RESULTS:MiR-9 inhibited while anti-miR-9 antisense oligonucleotides induced interleukin-1 beta (IL-1β) and NLRP3 inflammasome activation in all in vitro models. Janus kinase 1 (JAK1) and matrix metalloproteinase 13 (MMP-13) were identified as the target genes of miR-9. In oxLDL-stimulated human THP-1 derived macrophages, knockdown of JAK1 by siRNA blocked the phosphorylation of signal transducer and activator of transcription 1 (STAT1) and mimicked the effects of miR-9. In the same model, JAK1 knockdown blocked the phosphorylation of NF-κB p65 in the nuclei and the phosphorylation of NF-κB IκBα in the cytoplasm. CONCLUSIONS:Our study demonstrated that miR-9 could inhibit activation of the NLRP3 inflammasome and attenuate atherosclerosis-related inflammation, likely through the JAK1/STAT1 signaling pathway. Therefore, miR-9 may serve as a potential therapeutic target for atherosclerosis.
PKC-Mediated Endothelin-1 Expression in Endothelial Cell Promotes Macrophage Activation in Atherogenesis.
Zhang Juan,Wang Yan-Jiang,Wang Xin,Xu Lin,Yang Xin-Chun,Zhao Wen-Shu
American journal of hypertension
BACKGROUND:Atherosclerosis is a chronic inflammatory disease triggered by endothelial dysfunction and exaggerated by macrophage infiltration. Although endothelin-1 (ET-1) plays an important role in vascular inflammation and reactive oxygen species production, the individual effect of ET-1 in atherogenesis remains unclear. METHODS AND RESULTS:ET-1 expression was increased in mouse atherosclerotic plaques and human umbilical vein endothelial cells (HUVECs) administrated by oxidized low-density lipoprotein stimulation. Moreover, the immunofluorescence co-staining showed upregulated ET-1 expression in endothelial cells. Real-time polymerase chain reaction demonstrated that ET-1 overexpression promoted adhesion molecules and chemokines secretion in HUVECs. Following this intervention, the migration of macrophages and the pro-inflammatory cytokines were increased. More importantly, the endothelial dysfunction regulated by ET-1 and subsequently the effect on macrophage activation were mediated by ETA receptor and largely reversed by protein kinase C (PKC) inhibitor. Eight-week-old male ApoE-/- mice and eET-1/ApoE-/- mice were fed with high-fat diet for 12 weeks. eET-1/ApoE-/- significantly increased atherosclerotic lesions in the whole aorta and aortic sinus, which accompanied by the induction of inflammatory cytokines and macrophages infiltration. CONCLUSIONS:ET-1 accelerates atherogenesis by promoting adhesion molecules and chemokines, as well as subsequent macrophage activation. Collected, these evidence suggest that ET-1 might be a potential target for the treatment of atherogenesis.
Inhibition of long noncoding RNA HIF1A-AS2 confers protection against atherosclerosis ATF2 downregulation.
Li Pengcheng,Xing Junhui,Zhang Jielei,Jiang Jianwu,Liu Xuemeng,Zhao Di,Zhang Yanzhou
Journal of advanced research
Introduction:In atherosclerotic lesions, extensive inflammation of the vessel wall contributes to plaque instability. Long noncoding RNAs (lncRNAs) play important roles in diverse biological processes in atherosclerosis. Objectives:Here, we aim to identify the functional role and regulatory mechanisms of lncRNA hypoxia-inducible factor 1 alpha-antisense RNA 2 (HIF1A-AS2) in atherosclerotic inflammation. Methods:An atherosclerotic mouse model was induced in ApoE-/- mice by high fat diet (HFD). Endothelial cells (ECs), human aortic smooth muscle cells (SMCs) or human coronary artery endothelial cells (HCAECs) were exposed to ox-LDL to develop the in vitro model. The effects of lncRNA HIF1A-AS2 on inflammation were evaluated by determining levels of inflammatory factors tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) and levels of adhesion molecules vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), and macrophage cationic peptide 1 (MCP-1). Results:It was established that lncRNA HIF1A-AS2 and ATF2 were highly expressed in atherosclerotic ApoE-/- mice. Downregulating lncRNA HIF1A-AS2 in ox-LDL-exposed ECs, SMCs and HCAECs inhibited inflammation by reducing levels of pro-inflammatory factors and adhesion molecules. LncRNA HIF1A-AS2 bound to the transcription factor USF1 to elevate ATF2 expression. USF1 overexpression counteracted the suppressive effect of lncRNA HIF1A-AS2 silencing on ox-LDL-induced inflammation. Knockdown of lncRNA HIF1A-AS2 or ATF2 could also attenuate inflammation in atherosclerotic mice. Collectively, the present study demonstrates that downregulation of lncRNA HIF1A-AS2 represses the binding of USF1 to the ATF2 promoter region and then inhibits ATF2 expression, thereby suppressing atherosclerotic inflammation. Conclusion:This study suggests lncRNA HIF1A-AS2 as an promising therapeutic target for atherosclerosis.
Slfn4 deficiency improves MAPK-mediated inflammation, oxidative stress, apoptosis and abates atherosclerosis progression in apolipoprotein E-deficient mice.
Zheng Qianqian,Duan Liangwei,Lou Yunwei,Chao Tianzhu,Guo Guo,Lu Liaoxun,Zhang Hongxia,Zhao Yucong,Liang Yinming,Wang Hui
BACKGROUND AND AIMS:Atherosclerosis, a progressive inflammatory disease characterized by elevated inflammation and lipid accumulation in the aortic endothelium, arises in part from the infiltration of inflammatory cells into the vascular wall. However, it is not fully defined how inflammatory cells, especially macrophages, affect the pathogenesis of atherosclerosis. Schlafen4 (Slfn4) mRNA is remarkably upregulated upon ox-LDL stimulation in macrophages. Nonetheless, the role of Slfn4 in foam cell formation remains unclear. METHODS:To determine whether and how Slfn4 regulates lesion macrophage function during atherosclerosis，we engineered ApoESlfn4 double-deficient mice on an ApoE background and evaluated the deficiency of Slfn4 expression in atherosclerotic lesion formation in vivo. RESULTS:Our results demonstrate that total absence of SLFN4 and the bone marrow-restricted deletion of Slfn4 in ApoE mice remarkably diminish inflammatory cell numbers within arterial plaques as well as limit development of atherosclerosis in moderate hypercholesterolemia condition. This is linked to a marked reduction in the expression of proinflammatory cytokines, the generation of the reactive oxygen species (ROS) and the apoptosis of cells. Furthermore, the activation of MAPKs and apoptosis signaling pathways is compromised in the absence of Slfn4. CONCLUSIONS:These findings demonstrate a novel role of Slfn4 in modulating vascular inflammation and atherosclerosis, highlighting a new target for the related diseases.
Krüppel-like factor 14 inhibits atherosclerosis via mir-27a-mediated down-regulation of lipoprotein lipase expression in vivo.
Xie Wei,Li Liang,Gong Duo,Zhang Min,Lv Yun-Cheng,Guo Dong-Ming,Zhao Zhen-Wang,Zheng Xi-Long,Zhang Da-Wei,Dai Xiao-Yan,Yin Wei-Dong,Tang Chao-Ke
BACKGROUND AND AIMS:Krüppel-like factor 14 (KLF14) is known to play a role in atherosclerosis, but the underlying mechanisms are still largely unknown. The aim of our study was to explore the effects of KLF14 on lipid metabolism and inflammatory response, providing a potential target for lowering the risk of atherosclerosis-causing disease. METHODS AND RESULTS:mRNA and protein levels of KLF14 were significantly decreased in oxidized low-density lipoprotein (oxLDL)-treated macrophages and in the atherosclerotic lesion area. Chromatin immunoprecipitation (ChIP) and luciferase reporter gene assays were used to confirm that KLF14 positively regulated miR-27a expression by binding to its promoter. We also found that KLF14 could restored appropriate cellular lipid homeostasis and inflammatory responses via negatively regulating lipoprotein lipase (LPL) expression in THP1-derived macrophages through miR-27a. In addition, gypenosides (GP), a KLF14 activator, delayed the development of atherosclerosis in apolipoprotein E deficient (apoE) mice. CONCLUSIONS:KLF14 plays an antiatherogenic role via the miR-27a-dependent down-regulation of LPL and subsequent inhibition of proinflammatory cytokine secretion and lipid accumulation.
GDF-15 Suppresses Atherosclerosis by Inhibiting oxLDL-Induced Lipid Accumulation and Inflammation in Macrophages.
Huang Hong,Chen Zhongli,Li Yan,Gong Kunmei,Xiao Le,Fu Hao,Yang Jingjing,Wang Xianying,Meng Qiang
Evidence-based complementary and alternative medicine : eCAM
The growth differentiation factor-15 (GDF-15) may be involved in atherosclerosis. However, the role of GDF-15 in atherosclerosis remains unclear. The main goal of this study was to verify the role and mechanism of GDF-15 in atherogenesis. We first compared the serum GDF-15 level between patients with coronary atherosclerosis and healthy people. And then one ApoE mouse model of atherosclerosis was used to explore the effects of GDF-15 on oxidized low-density lipoprotein (oxLDL) accumulation, atherosclerosis-related gene expression, and lipid accumulation-related protein expression in mouse macrophages. As a result, the level of serum GDF-15 in patients with coronary atherosclerosis was significantly higher than that in healthy people. In the mouse model, GDF-15 expression was elevated in the core of plaque, and it was secreted mainly by the macrophages. In addition, GDF-15 decreased oxLDL-induced lipid accumulation and inflammation activation in macrophages. GDF-15 decreased the mRNA expressions of CD36, LOX1, and TLR4 that are associated with lipoprotein accumulation in macrophages. Further study showed that GDF-15 might suppress oxLDL-induced lipoprotein accumulation via inhibiting CD36 and LOX1 and decrease inflammation in macrophages by inhibiting TLR4. Thus, GDF-15 may suppress atherosclerosis and plaque formation by inhibiting lipoprotein accumulation and inflammation activation.
Swiprosin-1 deficiency in macrophages alleviated atherogenesis.
Tong Ling-Chang,Wang Zhi-Bin,Zhang Jia-Qi,Wang Yue,Liu Wei-Ye,Yin Hao,Li Jia-Cheng,Su Ding-Feng,Cao Yong-Bing,Zhang Li-Chao,Li Ling
Cell death discovery
Macrophages play a vital role in the development of atherosclerosis. Previously, we have found that swiprosin-1 was abundantly expressed in macrophages. Here, we investigated the role of swiprosin-1 expressed in macrophages in atherogenesis. Bone marrow transplantation was performed from swiprosin-1-knockout (Swp) mice and age-matched ApoE mice. Atherosclerotic lesion, serum lipid, and interleukin-β (IL-β) levels were detected. In vitro, the peritoneal macrophages isolated from Swp and wild-type mice were stimulated with oxidized low-density lipoprotein (ox-LDL) and the macrophage of foam degree, cellular lipid content, apoptosis, inflammatory factor, migration, and autophagy were determined. Our results showed that swiprosin-1 was mainly expressed in macrophages of atherosclerotic plaques in aorta from ApoE mice fed with high-cholesterol diet (HCD). The expression of swiprosin-1 in the foaming of RAW264.7 macrophages gradually increased with the increase of the concentration and time stimulated with ox-LDL. Atherosclerotic plaques, accumulation of macrophages, collagen content, serum total cholesterol, LDL, and IL-β levels were decreased in Swp → ApoE mice compared with Swp → ApoE mice fed with HCD for 16 weeks. The macrophage foam cell formation and cellular cholesterol accumulation were reduced, while the lipid uptake and efflux increased in macrophages isolated from Swp compared to wild-type mice treated with ox-LDL. Swiprosin-1 deficiency in macrophages could inhibit apoptosis, inflammation, migration, and promote autophagy. Taken together, our results demonstrated that swiprosin-1 deficiency in macrophages could alleviate the development and progression of AS. The role of swiprosin-1 may provide a promising new target for ameliorating AS.
Myeloid-Specific Deletion of Epsins 1 and 2 Reduces Atherosclerosis by Preventing LRP-1 Downregulation.
Brophy Megan L,Dong Yunzhou,Tao Huan,Yancey Patricia G,Song Kai,Zhang Kun,Wen Aiyun,Wu Hao,Lee Yang,Malovichko Marina V,Sithu Srinivas D,Wong Scott,Yu Lili,Kocher Olivier,Bischoff Joyce,Srivastava Sanjay,Linton MacRae F,Ley Klaus,Chen Hong
RATIONALE:Atherosclerosis is, in part, caused by immune and inflammatory cell infiltration into the vascular wall, leading to enhanced inflammation and lipid accumulation in the aortic endothelium. Understanding the molecular mechanisms underlying this disease is critical for the development of new therapies. Our recent studies demonstrate that epsins, a family of ubiquitin-binding endocytic adaptors, are critical regulators of atherogenicity. Given the fundamental contribution lesion macrophages make to fuel atherosclerosis, whether and how myeloid-specific epsins promote atherogenesis is an open and significant question. OBJECTIVE:We will determine the role of myeloid-specific epsins in regulating lesion macrophage function during atherosclerosis. METHODS AND RESULTS:We engineered myeloid cell-specific epsins double knockout mice (LysM-DKO) on an ApoE background. On Western diet, these mice exhibited marked decrease in atherosclerotic lesion formation, diminished immune and inflammatory cell content in aortas, and reduced necrotic core content but increased smooth muscle cell content in aortic root sections. Epsins deficiency hindered foam cell formation and suppressed proinflammatory macrophage phenotype but increased efferocytosis and anti-inflammatory macrophage phenotype in primary macrophages. Mechanistically, we show that epsin loss specifically increased total and surface levels of LRP-1 (LDLR [low-density lipoprotein receptor]-related protein 1), an efferocytosis receptor with antiatherosclerotic properties. We further show that epsin and LRP-1 interact via epsin's ubiquitin-interacting motif domain. ox-LDL (oxidized LDL) treatment increased LRP-1 ubiquitination, subsequent binding to epsin, and its internalization from the cell surface, suggesting that epsins promote the ubiquitin-dependent internalization and downregulation of LRP-1. Crossing ApoE/LysM-DKO mice onto an LRP-1 heterozygous background restored, in part, atherosclerosis, suggesting that epsin-mediated LRP-1 downregulation in macrophages plays a pivotal role in propelling atherogenesis. CONCLUSIONS:Myeloid epsins promote atherogenesis by facilitating proinflammatory macrophage recruitment and inhibiting efferocytosis in part by downregulating LRP-1, implicating that targeting epsins in macrophages may serve as a novel therapeutic strategy to treat atherosclerosis.
Allograft inflammatory factor-1 supports macrophage survival and efferocytosis and limits necrosis in atherosclerotic plaques.
Egaña-Gorroño Lander,Chinnasamy Prameladevi,Casimiro Isabel,Almonte Vanessa M,Parikh Dippal,Oliveira-Paula Gustavo H,Jayakumar Smitha,Law Calvin,Riascos-Bernal Dario F,Sibinga Nicholas E S
BACKGROUND AND AIMS:Allograft inflammatory factor-1 (AIF1) has been characterized as a pro-inflammatory molecule expressed primarily in the monocyte/macrophage (MP) lineage and positively associated with various forms of vascular disease, including atherosclerosis. Studies of AIF1 in atherosclerosis have relied on mouse models in which AIF1 was overexpressed in either myeloid or smooth muscle cells, resulting in increased atherosclerotic plaque burden. How physiologic expression of AIF1 contributes to MP biology in atherogenesis is not known. METHODS:Effects of global AIF1 deficiency on atherosclerosis were assessed by crossing Aif1 and ApoE mice, and provoking hyperlipidemia with high fat diet feeding. Atherosclerotic plaques were studied en face and in cross section. Bone marrow-derived MPs (BMDMs) were isolated from Aif1 mice for study in culture. RESULTS:Atherosclerotic plaques in Aif1;ApoE mice showed larger necrotic cores compared to those in ApoE animals, without change in overall lesion burden. In vitro, lack of AIF1 reduced BMDM survival, phagocytosis, and efferocytosis. Mechanistically, AIF1 supported activation of the NF-κB pathway and expression of related target genes involved in stress response, inflammation, and apoptosis. Consistent with this in vitro BMDM phenotype, AIF1 deficiency reduced NF-κB pathway activity in vivo and increased apoptotic cell number in atherosclerotic lesions from Aif1;ApoE mice. CONCLUSIONS:These findings characterize AIF1 as a positive regulator of the NF-κB pathway that supports MP functions such as survival and efferocytosis. In inflammatory settings such as atherosclerosis, these AIF1-dependent activities serve to clear cellular and other debris and limit necrotic core expansion, and may oppose lesion destabilization.
Interleukin-36 receptor antagonist attenuates atherosclerosis development by inhibiting NLRP3 inflammasome.
Tian Yuan,Ling Xue-Yan,Chen Dan-Ling,Zhang Xiu-Qiong,Qiu Chuan-Mei
Journal of cellular physiology
Atherosclerosis is characterized, as an inflammatory disorder in the circulatory system, with increasing tendency toward mortality and morbidity. Thus, developing novel therapeutic targeting inflammation is necessary. Here, we investigated the effects of interleukin-36 receptor antagonist (IL-36RN), a newly identified anti-inflammatory factor, on atherosclerosis. The regulation of NLRP3 inflammasome by IL-36RN was determined in vitro in macrophage cells after oxidized low-density lipoprotein (ox-LDL) stimulation. The IL-1β and caspase-1 p10 secretion were assessed by enzyme-linked immunosorbent assay and western blot analysis. Finally, the IL-36RN/NLRP3 inflammasome pathway was confirmed in apolipoprotein E-deficient mice. IL-36RN suppressed the expression of NLRP3, the secretion of IL-1β, and caspase-1 p10 in vitro, while IL-36 pathway stimulation activated the NLRP3 inflammasome, which was inhibited by IL-36RN. In the mouse model of atherosclerosis, IL-36RN delivered by the lentivirus vector inhibited the development of atherosclerosis, and the atheroprotective effects of IL-36RN were attenuated by IL-36 pathway stimulation. Furthermore, the regulation of NLRP3 inflammasome by IL-36RN was also confirmed in vivo. We demonstrated here that IL-36RN exerted atheroprotective functions through IL-36RN/NLRP3 inflammasome pathway.
Vimentin deficiency in macrophages induces increased oxidative stress and vascular inflammation but attenuates atherosclerosis in mice.
Håversen Liliana,Sundelin Jeanna Perman,Mardinoglu Adil,Rutberg Mikael,Ståhlman Marcus,Wilhelmsson Ulrika,Hultén Lillemor Mattsson,Pekny Milos,Fogelstrand Per,Bentzon Jacob Fog,Levin Malin,Borén Jan
The aim was to clarify the role of vimentin, an intermediate filament protein abundantly expressed in activated macrophages and foam cells, in macrophages during atherogenesis. Global gene expression, lipid uptake, ROS, and inflammation were analyzed in bone-marrow derived macrophages from vimentin-deficient (Vim) and wild-type (Vim) mice. Atherosclerosis was induced in Ldlr mice transplanted with Vim and Vim bone marrow, and in Vim and Vim mice injected with a PCSK9 gain-of-function virus. The mice were fed an atherogenic diet for 12-15 weeks. We observed impaired uptake of native LDL but increased uptake of oxLDL in Vim macrophages. FACS analysis revealed increased surface expression of the scavenger receptor CD36 on Vim macrophages. Vim macrophages also displayed increased markers of oxidative stress, activity of the transcription factor NF-κB, secretion of proinflammatory cytokines and GLUT1-mediated glucose uptake. Vim mice displayed decreased atherogenesis despite increased vascular inflammation and increased CD36 expression on macrophages in two mouse models of atherosclerosis. We demonstrate that vimentin has a strong suppressive effect on oxidative stress and that Vim mice display increased vascular inflammation with increased CD36 expression on macrophages despite decreased subendothelial lipid accumulation. Thus, vimentin has a key role in regulating inflammation in macrophages during atherogenesis.
Shen-Hong-Tong-Luo Formula Attenuates Macrophage Inflammation and Lipid Accumulation through the Activation of the PPAR-/LXR-/ABCA1 Pathway.
Zhang Zepeng,Zhai Lu,Lu Jing,Sun Sanmiao,Wang Dandan,Zhao Daqing,Sun Liwei,Zhao Weimin,Li Xiangyan,Chen Ying
Oxidative medicine and cellular longevity
Atherosclerosis (AS) is the killer of human health and longevity, which is majorly caused by oxidized lipoproteins that attack macrophages in the endarterium. The Shen-Hong-Tong-Luo (SHTL) formula has shown great clinical efficacy and vascular protective effect for over 30 years in China, to attenuate AS progression. However, its pharmacological mechanism needs more investigation. In this study, we first investigated the chemical composition of SHTL by fingerprint analysis using high-performance liquid chromatography. In primary mouse peritoneal macrophages induced by lipopolysaccharide (LPS), we found that SHTL pretreatment suppressed reactive oxygen species accumulation and reversed the increases of the inflammatory factors, TNF- and IL-6. Moreover, lipid accumulation induced by oxidized low-density lipoprotein (Ox-LDL) in macrophages was inhibited by SHTL. Additionally, network pharmacology was used to predict the potential targets of SHTL as the PPAR-/LXR-/ABCA1 signaling pathway, which was validated in macrophages and ApoE mice by histopathological staining, qPCR, and Western blot analysis. Importantly, the protective effect of SHTL in the LPS- and Ox-LDL-induced macrophages against inflammation and lipid accumulation was attenuated by GW9662, a PPAR- antagonist, which confirmed the prediction results of network pharmacology. In summary, these results indicated that SHTL pretreatment reduced inflammation and lipid accumulation of macrophages by activating the PPAR-/LXR-/ABCA1 pathway, which may provide a new insight into the mechanism of SHTL in the suppression of AS progression.
New role of PCSK9 in atherosclerotic inflammation promotion involving the TLR4/NF-κB pathway.
Tang Zhi-Han,Peng Juan,Ren Zhong,Yang Jing,Li Ting-Ting,Li Tao-Hua,Wang Zuo,Wei Dang-Heng,Liu Lu-Shan,Zheng Xi-Long,Jiang Zhi-Sheng
BACKGROUND AND AIMS:Proprotein convertase subtilisin/kexin 9 (PCSK9) has emerged as a popular target in the development of new cholesterol-lowering drugs and therapeutic interventions for atherosclerosis. PCSK9 could accelerate atherosclerosis through mechanisms beyond the degradation of the hepatic low-density lipoprotein receptor. Several clinical studies suggested that PCSK9 is involved in atherosclerotic inflammation. Accordingly, this study aimed to explore the role of PCSK9 in vascular inflammation that promotes atherosclerotic progression. METHODS:We examined whether PCSK9 silencing via transduction with the lentivirus-mediated PCSK9 shRNA (LV-PCSK9 shRNA) vector affects the formation of vascular lesions in hyperlipidemia-induced atherosclerosis in apolipoprotein E knockout (apoE KO) mice. In vitro, the effects of PCSK9 on oxLDL-induced macrophages inflammation were investigate using LV-PCSK9 and LV-PCSK9 shRNA for PCSK9 overexpression and PCSK9 silencing. RESULTS:Immunohistochemical analysis showed that PCSK9 expression increased within atherosclerotic plaques in apoE KO mice. These in vivo results showed that the LV-PCSK9 shRNA group of mice developed less aortic atherosclerotic plaques compared with the control group. These lesions also had the reduced number of macrophages and decreased expression of vascular inflammation regulators, such as tumor necrosis factor-α, interleukin 1 beta, monocyte chemoattractant protein-1, toll-like receptor 4 and nuclear factor kappa B (NF-κB). We further showed that PCSK9 overexpression in macrophages in vitro increased the secretion of oxLDL-induced proinflammatory cytokines. PCSK9 overexpression upregulated TLR4 expression and increased p-IκBα levels, IkBα degradation, and NF-κB nuclear translocation in macrophages, but PCSK9 knockdown had the opposite effects in oxLDL-treated macrophages. CONCLUSIONS:PCSK9 gene interference could suppress atherosclerosis directly through decreasing vascular inflammation and inhibiting the TLR4/NF-κB signaling pathway without affecting plasma cholesterol level in high-fat diet-fed apoE KO mice. PCSK9 may be an inflammatory mediator in the pathogenesis of atherosclerosis.
MiR-135a represses oxidative stress and vascular inflammatory events via targeting toll-like receptor 4 in atherogenesis.
Du Xian-Jin,Lu Jing-Min
Journal of cellular biochemistry
Plenty of microRNAs have been identified as critical mediators in atherosclerosis progression, which is still a great threat to human health. Oxidative stress and inflammation have been implicated to contribute a lot to atherosclerosis development. MiR-135a is abnormally expressed in various cancer types, however its function in atherosclerosis is largely unexplored. Ox-LDL is commonly recognized as a crucial atherosclerosis regulator. In our current study, we observed ox-LDL was able to induce RAW264.7 cell apoptosis and meanwhile miR-135a was restrained by ox-LDL both dose-dependently and time- dependently. CD36 has been reported to participate in atherosclerosis process and miR-135a mimics can inhibit its expression while miR-135a inhibitors exhibited a reverse phenomenon. Meanwhile, miR-135a overexpression can suppress foam cell formation, TC, TG levels, and cell apoptosis induced by 20 µg/mL ox-LDL. Subsequently, it was found that miR-135a overexpression can inhibit oxidative stress by decreasing ROS, MDA levels, and increasing SOD levels. Reversely, miR-135a inhibition demonstrated an inhibitory effect in vitro. Apart from these, miR-135a can also modulate inflammation molecules including IL-6, IL-1β, and TNF-α. TLR4 was predicted as a target of miR-135a and the negative correlation between them was confirmed by dual-luciferase reporter assay in our study. This work improves our understanding of atherosclerosis events mediated by miR-135a/TLR4 and helps to develop new approaches for atherosclerosis.
Sterol regulatory element binding protein (SREBP) -1 mediates oxidized low-density lipoprotein (oxLDL) induced macrophage foam cell formation through NLRP3 inflammasome activation.
Varghese Johnna F,Patel Rohit,Yadav Umesh C S
Macrophage foam cell formation (FCF) has long been known to play a critical role during atherosclerotic plaque development. In the presence of atherogenic molecules such as oxidized low-density lipoprotein (oxLDL) macrophages accumulate massive amounts of lipid through uptake. However, in the presence of oxLDL mechanism of dysregulated lipid homeostasis in the macrophages remains largely unknown. Herein we have investigated the role of Sterol regulatory element binding protein (SREBP)-1 in oxLDL-induced inflammation and altered lipid homeostasis in macrophages. The U937 monocytes and monocyte-derived macrophages (MDMs) were stimulated with different doses of oxLDL. MTT assay to study the effect of oxLDL on cell viability, Oil-Red-O (ORO) staining to observe cytosolic lipid accumulation, semi-quantitative PCR and Western blotting to analyze mRNA and protein expressions, respectively, and spectrophotometric assay to measure the lipid synthesizing enzyme's activity were performed. Our results indicate that oxLDL increased proliferation in monocytes and decreased the viability in MDMs in a time- and dose-dependent manner. The oxLDL (100 μg/ml) enhanced lipid accumulation via increased expressions of SREBP-1 and its downstream proteins such as fatty acid synthase (FAS) and 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) at both RNA and protein levels in monocytes as well as in MDMs. Inhibiting SREBP-1 by a synthetic inhibitor prevented excessive lipid accumulation by downregulating the expression of its downstream proteins. Further, oxLDL increased reactive oxygen species (ROS) levels, NLRP3 inflammasome activation and active interleukin 1β (IL-1β) release in both the cell types. The oxLDL-induced NLRP3 could be responsible for SREBP-1 and downstream proteins overexpression as siRNA silencing of NLRP3 decreased SERBP-1 levels. In summary, we have demonstrated that SREBP-1 could be a key player in oxLDL-induced excessive lipid accumulation leading to macrophage FCF via ROS-mediated NLRP3/IL-1β/SREBP-1 pathway.
C1q/TNF-related protein-9 attenuates atherosclerosis through AMPK-NLRP3 inflammasome singling pathway.
Zhang Hui,Gong Xinyang,Ni Shimao,Wang Yu,Zhu Lingbo,Ji Ningning
BACKGROUNDS:C1q tumor necrosis factor-related protein 9 (CTRP9) has been suggested to exert an atheroprotective effect by modulating the inflammation, foam cell formation, endothelia and smooth muscle cell function via Adenosine Monophosphate Activated Protein Kinase (AMPK) pathway. On the other hand, the NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome plays an critical role in the atherosclerosis development, which is regulated by the AMPK. However, whether the CTRP9 affects the activity of NLRP3 inflammasome during the atherosclerosis development remains unclear, which would be elucidated in the current study. METHODS:The macrophage cells were stimulated with the oxidized low-density lipoprotein (ox-LDL) and also treated with the recombinant CTRP9 in the meantime. The activation of NLRP3 inflammasome was determined by measuring the releasing of IL-1β and caspase-1 p10 via ELISA and western blot, respectively. Then the AMPK was inhibited in macrophages by Dorsomorphin. Finally, the CTRP9-AMPK-NLRP3 inflammasome pathway was validated in the mouse model of atherosclerosis. RESULTS:The CTRP9 could down-regulate the expression of NLRP3 protein and also the activity of NLRP3 inflammasome in the ox-LDL activated macrophages. Inhibiting the AMPK significantly restored the activities of NLRP3 inflammasome. In the apolipoprotein E-deficient mice, lentiviral expression of CTRP9 could suppress the atherosclerosis development, which could be abolished by AMPK inhibition. CONCLUSION:Our data here indicated that the CTRP9 showed atheroprotective function via CTRP9-AMPK- NLRP3 inflammasome pathway.
Increased macrophage activation mediated by caspase recruitment domain 6 knockdown through negatively targeting AMPK.
Chen Fangyuan,Li Juanli,Tian Gang,Yuan Zuyi
Biochemical and biophysical research communications
Caspase recruitment domain 6 (CARD6) was initially implicated in the immune system and oncogenesis, which has also been emerged to play an important role in cardio-metabolic diseases. Nevertheless, the potential role of CARD6 on macrophage activation remains unknown. In the present study, we observed a decreased CARD6 expression in bone marrow derived macrophages (BMDMs) and mouse peritoneal macrophages (MPMs) isolated from ApoE deficiency mice and administrated with OX-LDL, which were tested by RT-PCR and western bolt analysis. Moreover, the immunofluorescence co-staining revealed that a weaker immunoreactivity of CARD6 was found and primary located in cytoplasm of macrophages induced by OX-LDL. Phenotypically, loss-of-function of CARD6 dramatically increased pro-inflammatory M1 macrophage but decreased resolving M2 macrophage markers expression. Additionally, CARD6 knockdown significantly promoted cholesterol uptake but attenuated cholesterol efflux, which lead to increased foam cell formation. Mechanistically, a downregulated AMP-activated protein kinase (AMPK) expression was required for the promoted effect of CARD6 knockdown on macrophage activation. Taken together, these results suggest that CARD6 protects against macrophage activation partially through activation of AMPK-dependent mechanism.
MicroRNA-16 suppresses the activation of inflammatory macrophages in atherosclerosis by targeting PDCD4.
Liang Xue,Xu Zhao,Yuan Meng,Zhang Yue,Zhao Bo,Wang Junqian,Zhang Aixue,Li Guangping
International journal of molecular medicine
Programmed cell death 4 (PDCD4) is involved in a number of bioprocesses, such as apoptosis and inflammation. However, its regulatory mechanisms in atherosclerosis remain unclear. In this study, we investigated the role and mechanisms of action of PDCD4 in high-fat diet-induced atherosclerosis in mice and in foam cells (characteristic pathological cells in atherosclerotic lesions) derived from ox-LDL-stimulated macrophages. MicroRNA (miR)-16 was predicted to bind PDCD4 by bioinformatics analysis. In the mice with atherosclerosis and in the foam cells, PDCD4 protein expression (but not the mRNA expression) was enhanced, while that of miR‑16 was reduced. Transfection with miR‑16 mimic decreased the activity of a luciferase reporter containing the 3' untranslated region (3'UTR) of PDCD4 in the macrophage-derived foam cells. Conversely, treatment with miR‑16 inhibitor enhanced the luciferase activity. However, by introducing mutations in the predicted binding site located in the 3'UTR of PDCD4, the miR‑16 mimic and inhibitor were unable to alter the level of PDCD4, suggesting that miR‑16 is a direct negative regulator of PDCD4 in atherosclerosis. Furthermore, transfection wtih miR‑16 mimic and siRNA targeting PDCD4 suppressed the secretion and mRNA expression of pro-inflammatory factors, such as interleukin (IL)-6 and tumor necrosis factor-α (TNF‑α), whereas it enhanced the secretion and mRNA expression of the anti-inflammatory factor, IL-10. Treatment with miR‑16 inhibitor exerted the opposite effects. In addition, the phosphorylation of p38 and extracellular signal-regulated kinase (ERK), and nuclear factor-κB (NF-κB) expression were altered by miR‑16. In conclusion, our data demonstrate that the targeting of PDCD4 by miR‑16 may suppress the activation of inflammatory macrophages though mitogen-activated protein kinase (MAPK) and NF-κB signaling in atherosclerosis; thus, PDCD4 may prove to be a potential therapeutic target in the treatment of atherosclerosis.
MicroRNA-27 Prevents Atherosclerosis by Suppressing Lipoprotein Lipase-Induced Lipid Accumulation and Inflammatory Response in Apolipoprotein E Knockout Mice.
Xie Wei,Li Liang,Zhang Min,Cheng Hai-Peng,Gong Duo,Lv Yun-Cheng,Yao Feng,He Ping-Ping,Ouyang Xin-Ping,Lan Gang,Liu Dan,Zhao Zhen-Wang,Tan Yu-Lin,Zheng Xi-Long,Yin Wei-Dong,Tang Chao-Ke
Atherosclerotic lesions are lipometabolic disorder characterized by chronic progressive inflammation in arterial walls. Previous studies have shown that macrophage-derived lipoprotein lipase (LPL) might be a key factor that promotes atherosclerosis by accelerating lipid accumulation and proinflammatory cytokine secretion. Increasing evidence indicates that microRNA-27 (miR-27) has beneficial effects on lipid metabolism and inflammatory response. However, it has not been fully understood whether miR-27 affects the expression of LPL and subsequent development of atherosclerosis in apolipoprotein E knockout (apoE KO) mice. To address these questions and its potential mechanisms, oxidized low-density lipoprotein (ox-LDL)-treated THP-1 macrophages were transfected with the miR-27 mimics/inhibitors and apoE KO mice fed high-fat diet were given a tail vein injection with miR-27 agomir/antagomir, followed by exploring the potential roles of miR-27. MiR-27 agomir significantly down-regulated LPL expression in aorta and peritoneal macrophages by western blot and real-time PCR analyses. We performed LPL activity assay in the culture media and found that miR-27 reduced LPL activity. ELISA showed that miR-27 reduced inflammatory response as analyzed in vitro and in vivo experiments. Our results showed that miR-27 had an inhibitory effect on the levels of lipid both in plasma and in peritoneal macrophages of apoE KO mice as examined by HPLC. Consistently, miR-27 suppressed the expression of scavenger receptors associated with lipid uptake in ox-LDL-treated THP-1 macrophages. In addition, transfection with LPL siRNA inhibited the miR-27 inhibitor-induced lipid accumulation and proinflammatory cytokines secretion in ox-LDL-treated THP-1 macrophages. Finally, systemic treatment revealed that miR-27 decreased aortic plaque size and lipid content in apoE KO mice. The present results provide evidence that a novel antiatherogenic role of miR-27 was closely related to reducing lipid accumulation and inflammatory response via downregulation of LPL gene expression, suggesting a potential strategy to the diagnosis and treatment of atherosclerosis.
MiR-182-5p inhibited oxidative stress and apoptosis triggered by oxidized low-density lipoprotein via targeting toll-like receptor 4.
Qin Song-Bai,Peng Da-Yan,Lu Jing-Min,Ke Zun-Ping
Journal of cellular physiology
MicroRNAs (miRNAs) exhibit various roles in multiple biological processes and abnormal expression of miR-182-5p has been involved in many diseases. However, the role miR-182-5p in Atherosclerosis (AS) remains poorly understood. In our current investigation, an AS model was established by using oxidized low-density lipoprotein (ox-LDL) in RAW264.7 cells. miR-182-5p was markedly decreased in AS model dose-dependently and time-dependently. Additionally, CD36, oil-red staining levels, TC, and TG were inhibited by miR-182-5p mimics, meanwhile ROS levels, MDA, and cell apoptosis were also restrained with an enhancement of SOD activity. Consistently, opposite results were exhibited when miR-182-5p inhibitors were transfected into RAW264.7 cells. It is well known that toll-like receptor 4 (TLR4) is responsible for many inflammation diseases. By using bioinformatics analysis, TLR4 was indicated as a potential target of miR-182-5p. We observed TLR4 was activated in AS models and miR-182-5p could repress AS progression by targeting TLR4 in vitro. In conclusion, we uncovered that miR-182-5p played significant roles in AS through inhibiting oxidative stress and apoptosis via inactivating TLR4 expression.
FSTL3 Induces Lipid Accumulation and Inflammatory Response in Macrophages and Associates With Atherosclerosis.
Runhua Ma,Qiang Ji,Yunqing Shi,Wenjun Ding,Chunsheng Wang
Journal of cardiovascular pharmacology
FSTL3 as adipokine takes part in dyslipidemia and inflammatory response, but the association of FSTL3 with atherosclerosis is unclear. This study indicated that FSTL3 showed significantly higher level (control: 7.68 ± 3.10 vs. AS: 9.29 ± 2.37 ng/mL; P < 0.001) in atherosclerosis, and FSTL3 expressed higher in plaque of ApoE knockout mice and located in macrophages. Oxidized low-density lipoproteins induced expression and secretion of FSTL3, meanwhile FSTL3 promoted lipid accumulation in macrophages. The advanced study found that FSTL3 upregulated CD36 and LOX-1 expression in a dose-dependent manner; however, FSTL3 also evoked interleukin 1-β (IL1-β), monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor-α, and matrix metalloproteinase-9 (MMP-9) secretion in macrophages. On the contrary, that downregulated FSTL3 attenuated expression of oxidized low-density lipoproteins induced CD36, LOX-1, and inflammatory cytokines expressing. All of these results demonstrated that FSTL3 as a novelty cytokine takes part in the process of atherosclerosis through increasing lipid accumulation and inflammation through regulating CD36 and LOX-1 expression.
Intermedin Inhibits the Ox-LDL-Induced Inflammation in RAW264.7 Cells by Affecting Fatty Acid-Binding Protein 4 Through the PKA Pathway.
Liu Kai,Shi Rufeng,Wang Si,Liu Qi,Zhang Hengyu,Chen Xiaoping
Frontiers in pharmacology
Macrophages stimulated by oxidized low-density lipoprotein (ox-LDL) play an important role in the occurrence and progression of atherosclerosis. Fatty acid-binding protein 4 (FABP4), mainly existing in macrophages and adipocytes, can influence lipid metabolism and inflammation regulated by macrophages. Herein, we first established the connection between intermedin (IMD: a new peptide that has versatile biological activities in the cardiovascular system) and FABP4 and then investigated the influence of IMD on ox-LDL-induced changes in RAW264.7 macrophages line. The bioinformatics analysis, such as gene ontology enrichment and protein-protein interactions, was performed. For ox-LDL-stimulated assays, RAW264.7 was first pretreated with IMD and then exposed to ox-LDL. To explore the cell signaling pathways of IMD on inflammatory inhibition, main signaling molecules were tested and then cells were co-incubated with relevant inhibitors, and then exposed/not exposed to IMD. Finally, cells were treated with ox-LDL. The protein and gene expression of FABP4, IL-6, and TNF-α were quantified by WB/ELISA and RT-qPCR. In the ox-LDL-stimulated assays, exposure of the RAW264.7 macrophages line to ox-LDL reduced cell viability and increased the expression of FABP4, as well as induced the release of IL-6 and TNF-α (all < 0.05). On the other hand, IMD prevented ox-LDL-induced cell toxicity, FABP4 expression, and the inflammatory level in RAW264.7 (all < 0.05) in a dose-dependent manner. The inhibition of FABP4 and the anti-inflammatory effect of IMD were partially suppressed by the protein kinase A (PKA) inhibitor H-89. IMD can prevent ox-LDL-induced macrophage inflammation by inhibiting FABP4, whose signaling might partially occur via the PKA pathway.
C1q/TNF-related protein 1 links macrophage lipid metabolism to inflammation and atherosclerosis.
Wang Xiao Qun,Liu Zhu Hui,Xue Lu,Lu Lin,Gao Jie,Shen Ying,Yang Ke,Chen Qiu Jing,Zhang Rui Yan,Shen Wei Feng
BACKGROUND AND AIMS:Macrophage is a major contributor to the development of atherosclerosis by taking up deposited lipoprotein and eliciting local inflammation. Previously, we and others have shown C1q/TNF-related proteins (CTRPs) play diverse roles in vascular functions. In this study, we sought to investigate the changes in CTRP expression levels during vital biological processes in macrophages and their relation to inflammatory responses. METHODS:Western blot and real-time PCR were performed to analyze CTRPs expression levels in human peripheral blood mononuclear cells, primary macrophages and lipid-laden foam cells. Mechanisms that regulate CTPR1 expression were further investigated by bioinformatic analysis and chromatin immunoprecipitation. Enzyme-linked immunosorbent assay was performed to measure the concentration of inflammatory cytokines. RESULTS:We found that almost all CTRPs were significantly increased in primary human macrophages after differentiation from peripheral blood mononuclear cells. In particular, CTRP1 was further up-regulated upon exposure to oxidized low-density lipoprotein (oxLDL) in a peroxisome proliferator-activated receptor (PPAR)-dependent manner. Chromatin immunoprecipitation also confirmed the presence of PPAR-γ in the CTRP1 promoter after oxLDL treatment. Stimulation of CTRP1 led to markedly enhanced secretion of pro-atherogenic factors, including MCP-1, TNF-α, IL-1β, and IL-6, whereas oxLDL-induced inflammatory cytokine production was significantly attenuated after the treatment with CTRP1 neutralizing antibody. CONCLUSIONS:These data suggest an essential role of CTRP1 in linking dysregulation of lipid metabolism and inflammatory responses in macrophages.
Neat1 regulates oxidized low-density lipoprotein-induced inflammation and lipid uptake in macrophages via paraspeckle formation.
Huang-Fu Ning,Cheng Jing-Song,Wang Yong,Li Zhen-Wei,Wang Sheng-Huang
Molecular medicine reports
Oxidized low-density lipoprotein (oxLDL) indu-ces macrophage inflammation and lipid uptake, and serves important roles in the development of atherosclerosis. The long non-coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (neat1) has two isoforms; the longer isoform, neat1_2, mediates the formation of subnuclear structures called paraspeckles. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR), western blotting and RNA protein immunoprecipitation (RIP), revealed that oxLDL induced paraspeckle formation in the THP‑1 cell line. Additionally, the nuclear factor‑κB and p38 pathways were observed to be involved in neat1 transcription. To investigate the role of paraspeckles in oxLDL‑induced macrophage inflammation and lipid uptake, macrophages were transfected with small interfering RNAs against NEAT1, NEAT1_2, non‑POU domain-containing octamer-binding (NONO) and splicing factor proline and glutamine rich prior to oxLDL incubation. In addition, inflammation‑associated pathways and scavenger receptors were analyzed by performing western blotting and RT‑qPCR. p65 phosphorylation and cluster of differentiation 36 (CD36) were demonstrated to serve roles in paraspeckle‑mediated inflammation and lipid uptake, respectively. To determine the underlying mechanism, RIP was preformed, which revealed that NONO binds CD36 mRNA to decrease its expression. In conclusion, oxLDL induced neat1_2‑mediated paraspeckle formation. Paraspeckles participate in oxLDL‑induced macrophage inflammation and lipid uptake by regulating p65 phosphorylation and CD36 mRNA.
C/EBPβ Acts Upstream of NF-κB P65 Subunit in Ox-LDL-Induced IL-1β Production by Macrophages.
Ma Jun,Liu Chuan,Yang Yuanqi,Yu Jie,Yang Jie,Yu Sanjiu,Zhang Jihang,Huang Lan
Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology
BACKGROUND/AIMS:Interleukin-1β (IL-1β) is one of the critical inflammatory factors during atherogenesis. CCAAT/enhancer binding proteins β (C/EBPβ), a regulator of IL-1β production, recently been evidenced as a key player in the development of atherosclerosis. However, the mechanisms of how C/EBPβ regulates the production of IL-1β are unclear. In this study, we aimed to explore the role of C/EBPβ in regulating IL-1β production in macrophages after oxidized low-density lipoprotein (ox-LDL) exposure and the underlying mechanisms. METHODS:RAW264.7 macrophages were treated with 0, 25, 50 or 100 μg/ml ox-LDL for 12, 24 or 48 h. Small interfering RNAs were used to silence related proteins. The gene and protein expression levels were determined by quantitative real-time polymerase chain reaction or western blot (WB). IL-1β secretion was assessed by enzyme-linked immunosorbent assay. The cytoplasmic and nuclear proteins were evaluated by nuclear fractionation followed by WB. Localization of p65 was observed by immunofluorescence. The binding activity of p65 to IL-1β was tested by dual-luciferase reporter assay. RESULTS:Ox-LDL increased IL-1β production, accompanied with increasing C/EBPβ and p65 expression in a dose- and time-dependent manner. Moreover, C/EBPβ deficiency in macrophages blocked ox-LDL-induced increases in IL-1β expression, maturation as well as p65 activation. However, p65 deficiency inhibited the increase in IL-1β production, but not C/EBPβ expression. Dual-luciferase reporter results showed that overexpression of C/EBPβ significantly enhanced binding activity of p65 to IL-1β promoter. In addition, C/EBP 1β deficiency in macrophages abolished the ox-LDL-induced gene transcription increases of IL-1β, IL-6, p65 and caspase-1. CONCLUSIONS:Our results demonstrate that C/EBPβ acts upstream of NF-κB p65 subunit in ox-LDL-induced IL-1β production in macrophages and may regulate IL-1β maturation by promoting caspase-1. C/EBPβ may be a promising candidate for the prevention and treatment of atherosclerosis.
NEAT1 contributes to ox-LDL-induced inflammation and oxidative stress in macrophages through inhibiting miR-128.
Chen Dou-Dou,Hui Liang-Liang,Zhang Xiang-Cheng,Chang Qing
Journal of cellular biochemistry
Long noncoding RNAs (lncRNA) have been recognized as significant regulators in the progression of atherosclerosis (AS). Oxidized low-density lipoprotein (ox-LDL) can induce macrophage inflammation and oxidative stress, that serves important roles in AS. However, the exact function of lncRNA NEAT1 and its possible molecular mechanism in AS remain unclear. Here, we concentrated on the roles and molecular mechanisms of NEAT1 in AS development. In our current study, we observed that NEAT1 was elevated by ox-LDL in a dose-dependent and time-dependent manner. RAW264.7 cell survival was greatly enhanced, and cell apoptosis was significantly inhibited by LV-shNEAT1 transfection. In addition, knockdown of NEAT1 in RAW264.7 cells repressed CD36 expression and foam cell formation while NEAT1 overexpression shown an opposite process. Moreover, NEAT1 downregulation inhibited inflammation molecules including IL-6, IL-1β, and TNF-α. Meanwhile, silencing of NEAT1 can also suppress reactive oxygen species (ROS) and malondialdehyde (MDA) levels with an enhancement of superoxide dismutase (SOD) activity in RAW264.7 cells. MicroRNAs are some short RNAs, and they can regulate multiple biological functions in many diseases including AS. Here, we found that miR-128 expression was remarkably decreased in ox-LDL-incubated RAW264.7 cells. Interestingly, miR-128 mimics was able to reverse AS-correlated events induced by overexpression of NEAT1. By using bioinformatics analysis, miR-128 was predicted as a target of NEAT1 and the correlation between them was validated in our study. Taken these together, it was implied that NEAT1 participated in ox-LDL-induced inflammation and oxidative stress in AS development through sponging miR-128.
Silencing of GAS5 represses the malignant progression of atherosclerosis through upregulation of miR-135a.
Shen Songhe,Zheng Xiaoli,Zhu Zhixiang,Zhao Sen,Zhou Qing,Song Zhiming,Wang Guoliang,Wang Zhixue
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie
Long non-coding RNA growth arrest-specific 5 (GAS5) has been demonstrated to be involved in the pathogenesis of atherosclerosis (AS). The purpose of the present study was to investigate the underlying mechanisms of GAS5 on the inflammation and lipid metabolic disorders of AS. ApoE mice were fed on a high fat diet (HFD) and THP-1 macrophages were treated with ox-LDL to construct AS model in vivo and in vitro, respectively. The detections of blood lipids and inflammatory cytokines were performed using corresponding assay kits. qRT-PCR was used to assess the expression of GAS5 and miR-135a. Western blot was performed to detect PPARα and CPT1 levels. The targeted interaction between GAS5 and miR-135a was determined by dual-luciferase reporter assay and RNA immunoprecipitation assay. Our data revealed that GAS5 was upregulated in AS mice model and ox-LDL-treated macrophages. GAS5 silencing alleviated lipid metabolic disorders and inflammation in AS mice and ox-LDL-treated macrophages. Moreover, GAS5 directly targeted miR-135a and repressed miR-135a expression. MiR-135a expression restoration abrogated the alleviative effects of GAS5 silencing on inflammation and lipid metabolic disorders in ox-LDL-treated macrophages. In conclusion, our study suggested that GAS5 silencing repressed the malignant progression of AS at least partly through upregulation of miR-135a. Targeting GAS5 might be a promising treatment strategy for AS management.
Poria cocos polysaccharides attenuated ox-LDL-induced inflammation and oxidative stress via ERK activated Nrf2/HO-1 signaling pathway and inhibited foam cell formation in VSMCs.
Zhao Jinmeng,Niu Xinyi,Yu Jinjin,Xiao Xin,Li Wenqi,Zang Lulu,Hu Zhen,Siu-Po Ip Paul,Li Weifeng
Oxidative stress, inflammation, and foam cell formation in vascular smooth muscle cells (VSMCs) are considered to play crucial roles in the pathogenesis of atherosclerosis. Poria cocos polysaccharides (PCP) has been shown to possess anti-inflammatory, antitumor and anti-oxidative properties. In this study we explored the effects of PCP on ox-LDL-induced inflammation, oxidative stress and foam cell formation in VSMCs. PCP significantly attenuated ox-LDL-induced oxidative stress, as evidenced by the decreased reactive oxygen species (ROS) and MDA levels, and the increased SOD activity in VSMCs. PCP suppressed the induction effect of ox-LDL on inflammatory cytokines and inflammatory mediators. PCP also substantially inhibited VSMCs foam cell formation and intracellular lipids accumulation. Mechanistically, PCP suppressed ox-LDL-induced up-regulation of LOX-1, which is responsible for ox-LDL uptake. Western blotting suggested that PCP activated ERK1/2 signaling pathway, increased Nrf2 translocated from cytoplasm to nucleus and heme oxygenase-1 (HO-1) expression. Up-regulation of PCP on Nrf2/HO-1 signaling was reversed by pretreatment with ERK inhibitor PD98059, indicating the involvement of ERK in PCP activation of Nrf2/HO-1 signaling. In conclusion, these results demonstrated that PCP exerted its protection against oxidative stress and inflammation via the ERK/Nrf2/HO-1 signaling pathway and that PCP may be a promising candidate for the therapy of atherosclerosis.
LINC01140 Alleviates the Oxidized Low-Density Lipoprotein-Induced Inflammatory Response in Macrophages via Suppressing miR-23b.
He Liping,Zhao Xingsheng,He Leping
Our previous study has demonstrated that miR-23b enhances oxidized low-density lipoprotein (oxLDL)-induced inflammatory response of macrophages through the A20/NF-κB signaling pathway, thus contributing to atherosclerosis. This study aims to further investigate the upstream regulators of miR-23b in mediating oxLDL-induced inflammatory response. Human monocyte cell line THP1 was induced to differentiate into macrophages followed by the oxLDL stimulation of inflammatory response. The expression of miR-23b, LINC01140, and p53 mRNA was detected by quantitative PCR. The combination of miR-23b and LINC01140 was confirmed by luciferase reporter assay and RNA immunoprecipitation. The binding of p53 and LINC01140 promoter was determined by luciferase reporter assay. The level of inflammatory cytokines, including MCP-1, TNF-α, and IL-1β, was assessed by enzyme-linked immunosorbent assay. LINC01140 was downregulated, while p53 and miR-23b were upregulated in oxLDL-induced inflammatory response of macrophages. Overexpression of LINC01140 reduced NF-κB activity by reducing miR-23b and increasing A20. The transcription of LINC01140 was inhibited by binding of p53 and the LINC01140 promoter region. Knockdown of p53 significantly reduced NF-κB activity and level of inflammatory cytokines by promoting LINC01140 expression. Our findings demonstrated that LINC01140 acts as an anti-inflammatory factor through negatively regulating miR-23/A20 axis. In addition, p53 is identified as a transcriptional repressor of LINC01140.
Silencing of H19 inhibits the adipogenesis and inflammation response in ox-LDL-treated Raw264.7 cells by up-regulating miR-130b.
Han Yong,Ma Jie,Wang Junping,Wang Liping
Atherosclerosis (AS) is the main cause of cardiovascular diseases (CADs). Lipid accumulation and inflammatory response in macrophages are two key factors in the pathogenesis of AS. In this study, we aimed to explore the regulating role of long non-coding RNA (LncRNA)-H19 in oxygenized low density lipoprotein (ox-LDL)-treated Raw264.7 cells. Compared with the healthy control, a relatively higher level of H19 was detected in the blood samples from AS patients. Obviously up-regulated expression of TG (triglycerides)/TC (total cholesterol)/LDL-C (low density lipoprotein-cholesterol) and down-regulated level of HDL-C (high density lipoprotein-cholesterol) were detected in ox-LDL-treated Raw264.7 cells. Besides that, increased expression of H19 was detected in ox-LDL-treated Raw264.7 cells. To examine the function of H19, gene knockdown was performed using short hairpin RNAs (shRNAs). The expression of TG, TC, LDL-C and HDL-C was detected by enzyme linked immunosorbent assay (Elisa) and the expression of lipolytic genes/lipogenic genes (PPARα, CPT-1/REBP-1c, ACS) was examined through western blot. In combination with the result of oil red O staining, we concluded that H19 shRNA effectively decreased lipid accumulation in ox-LDL-treated Raw264.7 cells. Besides that, H19 shRNA decreased the level of pro-inflammatory factors (TNF-α, IL-1β)/CD68+ cells and increased the level of anti-inflammatory factors (IL-4, IL-10)/CD163+ cells compared with the control group. Combined the bioinformatics analyses/luciferase assay with the promoting effect of H19 shRNA on the expression of miR-130b, we speculated that miR-130b was a target of H19 in ox-LDL-treated Raw264.7 cells. Moreover, the adding of LncRNA H19 abolished the facilitating effect of miR-130b inhibitor on adipogenesis and inflammation response by up-regulating the expression of miR-130b. Taken together, our research indicated a H19-miR130b pathway in regulating lipid metabolism and inflammation response in ox-LDL-treated Raw264.7 cells, providing new targets for AS treatment.
TRIF Regulates BIC/miR-155 via the ERK Signaling Pathway to Control the ox-LDL-Induced Macrophage Inflammatory Response.
Wu Yaxi,Ye Jinshan,Guo Ruiwei,Liang Xing,Yang Lixia
Journal of immunology research
Toll/IL-1R-domain-containing adaptor-inducing IFN- (TRIF) is an important adaptor for TLR3- and TLR4-mediated inflammatory signaling pathways. Recent studies have shown that TRIF plays a key role in vessel inflammation and atherosclerosis; however, the precise mechanisms are unclear. We investigated the mechanisms of the TRIF-regulated inflammatory response in RAW264.7 macrophages under oxidized low-density lipoprotein (ox-LDL) stimulation. Our data show that ox-LDL induces TRIF, miR-155, and BIC expression, activates the ERK and SOCS1-STAT3-NF-B signaling pathways, and elevates the levels of IL-6 and TNF- in RAW264.7 cells. Knockdown of TRIF using TRIF siRNA suppressed BIC, miR-155, IL-6, and TNF- expression and inhibited the ERK and SOCS1-STAT3-NF-B signaling pathways. Inhibition of ERK signaling also suppressed BIC and miR-155 expression. These findings suggest that TRIF plays an important role in regulating the ox-LDL-induced macrophage inflammatory response and that TRIF modulates the expression of BIC/miR-155 and the downstream SOCS1-STAT3-NF-B signaling pathway via ERK. Therefore, TRIF might be a novel therapeutic target for atherosclerosis.
MicroRNA-181a regulates the activation of the NLRP3 inflammatory pathway by targeting MEK1 in THP-1 macrophages stimulated by ox-LDL.
Song Jinyang,Yang Shaonan,Yin Ruihua,Xiao Qi,Ma Aijun,Pan Xudong
Journal of cellular biochemistry
Atherosclerosis (AS) is a chronic inflammatory disease that is characterized by the deposition of lipids in the vascular wall and the formation of foam cells. Macrophages play a critical role in the development of this chronic inflammation. An increasing amount of research shows that microRNAs affect many steps of inflammation. The goal of our study was to investigate the regulatory effect of miR-181a on the NLRP3 inflammasome pathway and explore its possible mechanism. Compared with the control group, the expression of miR-181a was downregulated in the carotid tissue of AS group mice, while the expression of MEK1 and NLRP3-related proteins was upregulated significantly. In vitro, when THP-1 macrophages were stimulated with oxidized low-density lipoprotein (ox-LDL), the expression of miR-181a was decreased, the MEK/ERK/NF-κB inflammatory pathways were activated and the expression of NLRP3 inflammasome-related proteins was upregulated. Exogenous overexpression of miR-181a downregulated the activation of the MEK/ERK/NF-κB pathway and decreased the expression of NLRP3 inflammasome-related proteins (such as NLRP3, caspase-1, interleukin-18 [IL-18], IL-1β, etc). Exogenous miR-181a knockdown showed the opposite results to those of overexpression group. A luciferase reporter assay proved that miR-181a inhibited the expression of MEK1 by binding to its 3'-untranslated region. When we knocked down miR-181a and then treated cells with U0126 before ox-LDL stimulation, we found that U0126 reversed the increased activation of the MEK/ERK/NF-κB pathway and upregulation of NLRP3 inflammasome-related proteins (NLRP3, caspase-1, IL-18, IL-1β) that resulted from miR-181a knockdown. Our study suggests that miR-181a regulates the activation of the NLRP3 inflammatory pathway by altering the activity of the MEK/ERK/NF-κB pathway via targeting of MEK1.
miR-221 Alleviates the Ox-LDL-Induced Macrophage Inflammatory Response via the Inhibition of DNMT3b-Mediated NCoR Promoter Methylation.
Ye Jinshan,Wu Yaxi,Guo Ruiwei,Zeng Wenjun,Duan Yanan,Yang Zhihua,Yang Lixia
Mediators of inflammation
Atherosclerosis (AS) is a chronic inflammatory disease, and macrophages play a key role in all phases of AS. Recent studies have shown that miR-221 is a biomarker for AS and stroke; however, the role and mechanism of miR-221 in AS are unclear. Herein, we found that miR-221 and NCoR levels were decreased in ox-LDL-treated THP-1-derived macrophages. In contrast, DNMT3b, IL-6, and TNF- expression levels were increased under these conditions. Upregulation of miR-221 or NCoR could partially inhibit ox-LDL-induced IL-6 and TNF- expression. Further studies showed that DNMT3b was a target of miR-221. DNMT3b inhibition also suppressed IL-6 and TNF- expression and increased NCoR expression in the presence of ox-LDL. Moreover, DNMT3b was involved in ox-LDL-induced DNA methylation in the promoter region of NCoR. These findings suggest that miR-221 suppresses ox-LDL-induced inflammatory responses via suppressing DNMT3b-mediated DNA methylation in the promoter region of NCoR. These results provide a rationale for using intracellular miR-211 as a possible antiatherosclerotic target.
LncRNA SNHG16 promoted proliferation and inflammatory response of macrophages through miR-17-5p/NF-κB signaling pathway in patients with atherosclerosis.
An J-H,Chen Z-Y,Ma Q-L,Wang H-J,Zhang J-Q,Shi F-W
European review for medical and pharmacological sciences
OBJECTIVE:Atherosclerosis (AS) is a leading cause of cardiovascular disease (CVD), which is also the leading reason for mortality and morbidity worldwide. Growing evidence has shown that long non-coding RNAs (lncRNAs) play some roles in the development of AS; however, their roles remain unclear. In this study, we aimed to explore the function of lncRNA SNHG16 in AS. PATIENTS AND METHODS:qRT-PCR was used to detect the expressions of SNHG16 and miR-17-5p in AS serum samples and THP-1 macrophage-derived foam cells; the correlations were also analyzed. THP-1 macrophages were respectively treated with ox-LDL and several inflammatory factors to explore the affecting factors. What's more, SNHG16 overexpression lentivirus (LV-SNHG16) and downregulation lentivirus (LV-sh SNHG16) were purchased and infected into THP-1 macrophages. CCK8 assay was used to measure cell proliferation; the levels of IKKβ, p-IkBα and p-p65 were detected by western blot (WB), and the levels of TNF-α, IL-1β and IL-6 were detected by ELISA kit. Moreover, the luciferase assay was performed to explore the binding site of SNHG16 and miR-17-5p. Furthermore, we transfected miR-17-5p mimic and inhibitor into THP-1 macrophages; the proliferation, NF-κB signaling pathway factors and inflammatory factors were detected. Finally, JSH, a NF-κB signaling inhibitor, was added into LV-SNHG16 THP-1 macrophages and miR-17-5p inhibitor was transfected into LV-sh SNHG16 THP-1 macrophages to confirm that SNHG16 functions via miR-17-5p/ NF-κB signaling pathway. RESULTS:We found that SNHG16 was increased in AS patients and THP-1 macrophage-derived foam cells. Additionally, SNHG16 was increased in THP-1 macrophages by ox-LDL with time-dependence and dose-dependence. Furthermore, SNHG16 overexpression promoted proliferation, inflammatory response and increased levels of IKKβ, p-IkBα, p-p65 in THP-1 macrophages, while SNHG16 downregulation led to the opposite results. Most importantly, we found that miR-17-5p expressions were significantly decreased in AS patients, which were negatively correlated with SNHG16. Luciferase gene reporter assay confirmed that SNHG16 could directly bind with miR-17-5p. Moreover, the proliferation, inflammatory factors and NF-κB signaling factors were significantly repressed after transfecting miR-17-5p mimic into THP-1 macrophages, while it led to the opposite results after transfecting miR-17-5p inhibitor. Then, we added JSH, a NF-κB signaling inhibitor, into LV-SNHG16 THP-1 macrophages; as a result, the increased cell proliferation rate and inflammatory response were both decreased. Finally, we found that the repressed cell proliferation, inflammatory factors and expressions of NF-κB signaling factors in LV-sh SNHG16 group were increased after co-transfected with miR-17-5p inhibitor. CONCLUSIONS:According to the results, we found that SNHG16 was upregulated in AS patients. Furthermore, we firstly found that SNHG16 was increased by ox-LDL in THP-1 macrophages. Most importantly, we uncovered a previously unappreciated SNHG16/miR-17-5p/ NF-κB signaling axis in promoting proliferation and inflammatory response in AS patients and THP-1 macrophages, which might provide a potential target for treating AS.
MiR-210-3p attenuates lipid accumulation and inflammation in atherosclerosis by repressing IGF2.
Qiao Xiang-Rui,Wang Liang,Liu Mengping,Tian Yuling,Chen Tao
Bioscience, biotechnology, and biochemistry
Previous studies have shown that miR-210-3p is involved in the development and progression of atherosclerosis, but its specific mechanisms are still unclear. This study aims to reveal the mechanism of miR-210-3p and its target genes in macrophage lipid deposition and inflammatory response, and provide new ideas for the treatment of atherosclerosis. We found miR-210-3p increased sharply in the first 12 h induced by higher doses of ox-LDL in THP-1 macrophages and then gradually decreased. MiR-210-3p mimic transfection inhibited lipid uptake and inflammatory cytokine production in ox-LDL-induced macrophages. By inhibiting IGF2/IGF2R, miR-210-3p suppressed the expression of fatty acid transcriptase CD36 and transcription factor NF-κB in ox-LDL-induced macrophages. In conclusion, miR-210-3p inhibits the expression of CD36 and NF-κB by inhibiting IGF2 / IGF2R, thereby reducing lipid accumulation and inflammatory response in ox-LDL-induced macrophages. Enhancing miR-210-3p expression may be a new strategy for the treatment of atherosclerosis.
Forkhead box protein 1 transcriptionally activates sestrin1 to alleviate oxidized low-density lipoprotein-induced inflammation and lipid accumulation in macrophages.
Gao Feng,Zhao Yongcheng,Zhang Bin,Xiao Chunwei,Sun Zhanfa,Gao Yuan,Dou Xueyong
Transcription factor forkhead box protein 1 (FOXP1) has been shown cardiovascular protection. We aimed to analyze the role of FOXP1 in oxidized low-density lipoprotein (ox-LDL)-induced macrophages and its possible regulatory effect on sestrin1 (SESN1) expression. After stimulation with ox-LDL, FOXP1 expression in RAW264.7 cells was evaluated with RT-qPCR and Western blotting. Then, FOXP1 was overexpressed, followed by detection of inflammatory mediator levels using ELISA kits and RT-qPCR. Lipid accumulation was detected with oil red O staining. Additionally, the JASPAR database was used to predict the potential genes that could be transcriptionally regulated by FOXP1. ChIP and luciferase reporter assays were used to verify this combination. To further clarify the regulatory effects of FOXP1 on SESN1 in damage of macrophages triggered by ox-LDL, SESN1 was silenced to determine the inflammation and lipid accumulation under the condition of FOXP1 overexpression. Results indicated that ox-LDL stimulation led to a significant decrease in FOXP1 expression. FOXP1 overexpression notably reduced the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6, accompanied by a decreased in phosphorylated NF-κB p65 expression. Besides, FOXP1-upregulation inhibited lipid accumulation and reduced CD36 expression level in RAW264.7 cells upon ox-LDL stimulation. Moreover, results of ChIP and luciferase reporter assays suggested that FOXP1 could transcriptionally regulate SESN1 expression. Further experiments supported that SESN1 silencing restored the inhibitory effects of FOXP1 overexpression on the inflammation and lipid accumulation in RAW264.7 cells exposed to ox-LDL. Collectively, FOXP1 transcriptionally activates SESN1 for the alleviation of ox-LDL-induced inflammation and lipid accumulation in macrophages.
Enhanced atherosclerosis in TIPE2-deficient mice is associated with increased macrophage responses to oxidized low-density lipoprotein.
Lou Yunwei,Liu Suxia,Zhang Cheng,Zhang Guizhong,Li Jingjing,Ni Mei,An Guipeng,Dong Mei,Liu Xiaoling,Zhu Faliang,Zhang Wenqian,Gao Fei,Chen Youhai H,Zhang Yun
Journal of immunology (Baltimore, Md. : 1950)
Atherosclerosis has been widely recognized as an inflammatory disease of the arterial wall in which macrophages play a major role. Yet, how macrophage-mediated pathology is regulated during atherosclerosis is poorly understood. TNF-α-induced protein 8-like 2 (TIPE2, also known as TNFAIP8L2) is highly expressed in resting macrophages and can negatively regulate inflammation through inhibiting immune receptor signaling. We report in this article that TIPE2 plays a crucial atheroprotective role likely by regulating macrophage responses to oxidized low-density lipoprotein (ox-LDL). TIPE2-deficient macrophages treated with ox-LDL produced more oxidative stress and proinflammatory cytokines, and exhibited heightened activation of the JNK, NF-κB, and p38 signaling pathways. As a consequence, TIPE2 deficiency in bone marrow-derived cells exacerbated atherosclerosis development in Ldlr(-/-) mice fed a high-fat diet. Importantly, ox-LDL markedly downregulated TIPE2 mRNA and protein levels in macrophages, suggesting that ox-LDL mediates atherosclerosis by TIPE2 inhibition. These results indicate that TIPE2 is a new inhibitor of atherosclerosis and a potential drug target for treating the disease.
Endothelial extracellular vesicles modulate the macrophage phenotype: Potential implications in atherosclerosis.
He S,Wu C,Xiao J,Li D,Sun Z,Li M
Scandinavian journal of immunology
Endothelial cells (ECs) and macrophages engage in tight and specific interactions that play critical roles in cardiovascular homeostasis and the pathogenesis of atherosclerosis. Extracellular vesicles (EVs) are circular membrane fragments released from the endosomal compartment as exosomes or shed from the surfaces of the membranes of most cell types. Increasing evidence indicates that EVs play a pivotal role in cell-to-cell communication. However, the contribution of EVs, as determine by oxidized low-density lipoprotein (ox-LDL)-exposed and/or Kruppel-like factor 2 (KLF2)-transduced ECs in the interaction between vascular ECs and monocytes/macrophages, which is a key event in atherosclerotic plaque development, has remained elusive. This study demonstrates the characteristic impact of EVs from ox-LDL-treated and/or KLF2-transduced ECs on the monocyte/macrophage phenotype in vitro and in vivo.Q-PCR showed that both the atherosclerosis inducer ox-LDL and atheroprotective factor KLF2 regulated inflammation-associated microRNA-155 (miR-155) expression in human umbilical vein endothelial cells (HUVECs). Moreover, coculture, immunofluorescence and flow cytometry revealed that miR-155 was enriched in ox-LDL-induced ECs-EVs and subsequently transferred to human monocytic THP1 cells, in which these vesicles enhance monocyte activation by shifting the monocytes/macrophages balance from anti-inflammatory M2 macrophages towards proinflammatory M1 macrophages; EVs from KLF2-expressing ECs suppressed monocyte activation by enhancing immunomodulatory responses and diminishing proinflammatory responses, which indicate the potent anti-inflammatory activities of these cells. Furthermore, oil red staining showed that atherosclerotic lesions were reduced in mice that received EVs from KLF2-transduced ECs with decreased proinflammatory M1 macrophages and increased anti-inflammatory M2 macrophages, and this effect is at least partly due to the decreased expression of inflammation-associated miR-155, confirming our in vitro findings. In summary, this study provides novel insights into the pathophysiological effects of altered EV secretion and/or microRNA content and their influence on modulating monocyte activation depending on the environment surrounding EVs-releasing ECs.
MiR-370 inhibits vascular inflammation and oxidative stress triggered by oxidized low-density lipoprotein through targeting TLR4.
Tian Dan,Sha Yin,Lu Jing-Min,Du Xian-Jin
Journal of cellular biochemistry
Atherosclerosis, as a chronic cardiovascular disease, still remains a serious threat to human health. Inflammation and oxidative stress are commonly involved in various stages of atherosclerosis development. MicroRNAs are reported to play important roles in macrophages, which can respond to inflammation and oxidative stress. In our current study, we focused on the biological roles of miR-370 in atherosclerosis. According to the previously research, miR-370 was downregulated in AS mice models. Oxidized low-density lipoprotein (Ox-LDL) is regarded as a crucial regulator of atherosclerosis and we observed that miR-370 was decreased by ox-LDL dose-dependently and time-dependently in THP-1 cells. Then, it was found that miR-370 overexpression was able to inhibit inflammation molecules including IL-6 and IL-1β. Meanwhile, ROS levels, and malondialdehyde (MDA) were also restrained by miR-370 mimics in vitro. Toll-like receptor 4 (TLR4) has been implicated in many inflammation diseases. It can serve as a target of miR-370 and TLR4 expression was greatly increased in ox-LDL-incubated THP-1 cells in a time and dose dependent manner. The negative correlation was validated using a dual-luciferase reporter assay in our study. In conclusion, our present study revealed that miR-370 can reduce inflammatory reaction and inhibit the ROS production by targeting TLR4 in THP-1 cells.
LncRBA GSA5, up-regulated by ox-LDL, aggravates inflammatory response and MMP expression in THP-1 macrophages by acting like a sponge for miR-221.
Ye Jiumin,Wang Chongbao,Wang Dongqi,Yuan Huijun
Experimental cell research
Atherosclerosis is a chronic inflammatory process, plaque rupture and subsequent thrombosis underline the major causes of acute cardio-cerebral vascular diseases. Long non-coding RNAs (lncRNAs) participate in diverse pathologic processes, including inflammation and myocardial infarction. Recent study confirmed the elevation of lncRNA growth arrest-specific 5 (GAS5) in atherosclerotic rats. In this study, we aimed to explore the role and mechanism of GAS5 in the progression of atherosclerotic plaque. Here, expression of GAS5 was enriched in atherosclerotic plaques and THP-1 macrophage exposed to oxidized low-density lipoprotein (ox-LDL). Furthermore, overexpression of GAS5 aggravated ox-LDL-induced pro-inflammatory cytokines (IL-6, IL-1β, TNF-α) and chemokine MCP-1 secretion in macrophages, which were reversed after GAS5 cessation. Additionally, high expression and secretion of MMP-2 and MMP-9 were increased in ox-LDL-stimulated macrophages following GAS5 elevation, but these increases were inhibited in GAS5-silenced group. Mechanism analysis identified GAS5 as a endogenous sponge to directly bind and suppress miR-221 expression. Notably, miR-221 elevation antagonized GAS5-enhanced inflammatory response and MMPs in macrophages upon ox-LDL. These results suggest that GAS5 can trigger inflammatory response and MMP expression by acting as a sponge of miR-221, which may facilitate fibrous cap degradation and aggravate atherosclerotic plaque destabilization, supporting a promising therapeutic agent against atherosclerosis.
iRhom2 promotes atherosclerosis through macrophage inflammation and induction of oxidative stress.
Chaohui Cheng,Wei Huang,Hongfeng Wen,Yueliang Zhang,Xiaoqin Peng,Pingli Zhou,Zhibing Ai
Biochemical and biophysical research communications
Atherosclerosis is a complex chronic inflammatory disease that is characterized by the formation of lipid-rich plaques on the inner walls of the arteries. Inactive rhomboid protein 2 (iRhom2) was recently determined as a necessary regulator for the shedding of tumor necrosis factor-alpha (TNF-α) in immune cells. In the present study, we aimed to explore the effects of iRhom2 on the inflammatory response and oxidative stress induced by low-density lipoprotein (ox-LDL) in RAW264.7 and THP-1-derived macrophages. The expression levels of iRhom2 were also investigated in apolipoprotein E knockout (ApoE) mice fed a high-fat diet (HFD). iRhom2 was significantly induced by ox-LDL in macrophages, as confirmed by Western blotting and RT-qPCR analysis. Furthermore, iRhom2 knockdown showed significant suppressive effects on the activation of ox-LDL-induced RAW264.7 and THP-1-derived macrophages through reducing TACE and TNFR2 expressions, and the inactivation of the IκBα/NF-κB signaling pathway. A reduction in reactive oxygen species (ROS) generation, malondialdehyde (MDA) levels, and nitric oxide (NOX) activity and an increase in glutathione peroxidase (GSH-Px) activity were determined in the absence of iRhom2 expression. In addition, the NF-E2 related factor-2 (Nrf-2)/heme oxygenase-1 (HO-1) pathway was also upregulated in ox-LDL-treated macrophages subjected to iRhom2 inhibition. Moreover, suppression of iRhom2 expression inactivated PI3K/AKT pathway activation, contributing to ROS reduction in ox-LDL-stimulated macrophages. iRhom2 was also significantly expressed in ApoE mice fed HFD. Finally, we observed increased serum levels of TNF-α, TNFR1, and TNFR2 in patients with coronary artery atherosclerosis as compared to healthy volunteers. In conclusion, our findings suggested that iRhom2 played a key role in the pathogenesis of atherosclerosis, and that iRhom2 might be a potential therapeutic target against atherosclerosis.
Silence of long intergenic noncoding RNA HOTAIR ameliorates oxidative stress and inflammation response in ox-LDL-treated human macrophages by upregulating miR-330-5p.
Liu Jie,Huang Guang-Qing,Ke Zun-Ping
Journal of cellular physiology
Evidence of the involvement of long noncoding RNAs (lncRNAs) in atherosclerosis is growing but still not well characterized. Here, we concentrated on the biological roles of lncRNA HOX transcription antisense RNA (HOTAIR) in atherosclerosis. In our study, we found that oxidized low-density lipoprotein (ox-LDL) induced human macrophages THP-1 cells apoptosis dose dependently and time dependently. Meanwhile, HOTAIR was significantly increased in THP-1 cells treated with ox-LDL. Then, HOTAIR was modulated by infection of LV-short hairpin RNA (shRNA) and LV-HOTAIR into THP-1 cells. As displayed, CD36, Oil Red O staining levels, total cholesterol, triglyceride levels and dil-ox-LDL uptake rate were greatly repressed by the silence of HOTAIR while triggered by overexpression of HOTAIR. Moreover, knockdown of HOTAIR suppressed reactive oxygen species, malondialdehyde levels, increased superoxide dismutase activity and cell apoptosis were also restrained. Reversely, overexpression of HOTAIR exhibited an opposite phenomenon. In addition, interleukin 6 (IL-6), IL-1β, cyclo-oxygenase 2, and tumor necrosis factor α protein levels were significantly depressed by LV-shRNA) of HOTAIR while increased by upregulation of HOTAIR in THP-1 cells. By carrying out bioinformatics analysis, miR-330-5p was predicted as a target of HOTAIR and the correlation between them was validated in our current study. MiR-330-5p was greatly decreased in THP-1 cells incubated with ox-LDL and overexpression of miR-330-5p was able to inhibit oxidative stress and inflammation process. Taken together, it was implied that HOTAIR contributed to atherosclerosis development by downregulating miR-330-5p in human macrophages.
Blockade of NEAT1 represses inflammation response and lipid uptake via modulating miR-342-3p in human macrophages THP-1 cells.
Wang Lei,Xia Jing-Wen,Ke Zun-Ping,Zhang Bing-Hong
Journal of cellular physiology
Atherosclerosis has been recognized as a chronic inflammation process induced by lipid of the vessel wall. Oxidized low-density lipoprotein (ox-LDL) can drive atherosclerosis progression involving macrophages. Recently, long noncoding RNAs (lncRNAs) have been reported to play critical roles in atherosclerosis development. In our current study, we focused on the biological roles of lncRNA NEAT1 in atherosclerosis progress. Here, we found that ox-LDL was able to trigger human macrophages THP-1 cells, a human monocytic cell line, apoptosis in a dose-dependent and time-dependent course. In addition, we observed that NEAT1 was significantly increased in THP-1 cells incubated with ox-LDL and meanwhile miR-342-3p was greatly decreased. Then, NEAT1 was silenced by transfection of small interfering RNA (siRNA) of NEAT1 into THP-1 cells. As exhibited, CD36, oil-red staining levels, total cholesterol (TC), total cholesterol (TG) levels and THP-1 cell apoptosis were obviously repressed by knockdown of NEAT1. Furthermore, inhibition of NEAT1 contributed to the repression of inflammation in vitro. Interleukin 6 (IL-6), IL-1β, cyclooxygenase-2 (COX-2) and tumour necrosis factor-alpha (TNF-α) protein levels were remarkably depressed by NEAT1 siRNA in THP-1 cells. By using bioinformatics analysis, miR-342-3p was predicted as a downstream target of NEAT1 and the correlation between them was confirmed in our study. Moreover, overexpression of miR-342-3p could also greatly suppress inflammation response and lipid uptake in THP-1 cells. Knockdown of NEAT1 and miR-342-3p mimics inhibited lipid uptake in THP-1 cells. In conclusion, we implied that blockade of NEAT1 repressed inflammation response through modulating miR-342-3p in human macrophages THP-1 cells and NEAT1 may offer a promising strategy to treat atherosclerotic cardiovascular diseases.
ERV1/ChemR23 Signaling Protects Against Atherosclerosis by Modifying Oxidized Low-Density Lipoprotein Uptake and Phagocytosis in Macrophages.
Laguna-Fernandez Andres,Checa Antonio,Carracedo Miguel,Artiach Gonzalo,Petri Marcelo H,Baumgartner Roland,Forteza Maria J,Jiang Xintong,Andonova Teodora,Walker Mary E,Dalli Jesmond,Arnardottir Hildur,Gisterå Anton,Thul Silke,Wheelock Craig E,Paulsson-Berne Gabrielle,Ketelhuth Daniel F J,Hansson Göran K,Bäck Magnus
BACKGROUND:In addition to enhanced proinflammatory signaling, impaired resolution of vascular inflammation plays a key role in atherosclerosis. Proresolving lipid mediators formed through the 12/15 lipoxygenase pathways exert protective effects against murine atherosclerosis. n-3 Polyunsaturated fatty acids, including eicosapentaenoic acid (EPA), serve as the substrate for the formation of lipid mediators, which transduce potent anti-inflammatory and proresolving actions through their cognate G-protein-coupled receptors. The aim of this study was to identify signaling pathways associated with EPA supplementation and lipid mediator formation that mediate atherosclerotic disease progression. METHODS:Lipidomic plasma analysis were performed after EPA supplementation in Apoe mice. Erv1/Chemr23 xApoe mice were generated for the evaluation of atherosclerosis, phagocytosis, and oxidized low-density lipoprotein uptake. Histological and mRNA analyses were done on human atherosclerotic lesions. RESULTS:Here, we show that EPA supplementation significantly attenuated atherosclerotic lesion growth induced by Western diet in Apoe mice and was associated with local cardiovascular n-3 enrichment and altered lipoprotein metabolism. Our systematic plasma lipidomic analysis identified the resolvin E1 precursor 18-monohydroxy EPA as a central molecule formed during EPA supplementation. Targeted deletion of the resolvin E1 receptor Erv1/Chemr23 in 2 independent hyperlipidemic murine models was associated with proatherogenic signaling in macrophages, increased oxidized low-density lipoprotein uptake, reduced phagocytosis, and increased atherosclerotic plaque size and necrotic core formation. We also demonstrate that in macrophages the resolvin E1-mediated effects in oxidized low-density lipoprotein uptake and phagocytosis were dependent on Erv1/Chemr23. When analyzing human atherosclerotic specimens, we identified ERV1/ChemR23 expression in a population of macrophages located in the proximity of the necrotic core and demonstrated augmented ERV1/ChemR23 mRNA levels in plaques derived from statin users. CONCLUSIONS:This study identifies 18-monohydroxy EPA as a major plasma marker after EPA supplementation and demonstrates that the ERV1/ChemR23 receptor for its downstream mediator resolvin E1 transduces protective effects in atherosclerosis. ERV1/ChemR23 signaling may represent a previously unrecognized therapeutic pathway to reduce atherosclerotic cardiovascular disease.
Fibroblast growth factor 21 regulates foam cells formation and inflammatory response in Ox-LDL-induced THP-1 macrophages.
Wang Nan,Li Jun-Yan,Li Shuai,Guo Xiao-Chen,Wu Tong,Wang Wen-Fei,Li De-Shan
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie
Macrophages are paramount to the initiation and procession of atherosclerosis, thus targeting macrophages in the progress of atherosclerosis is indispensable. Therefore, we perform in vitro experiments to investigate the effects of FGF-21 on macrophages in the progress of atherosclerosis. First, we use phorbol-12-myristate-13-acetate (PMA), a phorbol ester, to induce THP-1 cells into macrophages as macrophages model. After that we use Ox-LDL to induce macrophages into foam cells and simultaneously administrate with FGF-21 or not to determine whether FGF-21 has effects on foam cells formation and related inflammatory response. Wound healing results show that FGF-21 can inhibit macrophage migration. Oil Red-O stain, immunofluorescence and flow cytometer results show that FGF-21 can repress cholesterol accumulation in macrophages thereby inhibit foam cells formation and these effects can be abolished by FGFR inhibitor. Moreover, real-time PCR results showed that FGF-21 significantly reduces expression of inflammatory factors including IL-1α, IL-6 and TNF-α and this effect can be abolished by FGFR inhibitor. Furthermore, to determine the mechanism of FGF-21 regulates inflammatory response in Ox-LDL-induced THP-1 macrophages, western blotting results show that after treatment of Ox-LDL in macrophages, NF-κB signaling pathway is activated but FGF-21 can significantly inhibit this pathway. In addition, FGF-21 also regulates some regulators of lipid metabolism after treatment of Ox-LDL in macrophages. Above all, our findings demonstrate that FGF-21 can regulate foam cells formation, macrophage migration, inflammatory response and lipid metabolism in Ox-LDL-induced THP-1 macrophages.
Silencing of MEG3 inhibited ox-LDL-induced inflammation and apoptosis in macrophages via modulation of the MEG3/miR-204/CDKN2A regulatory axis.
Yan Long,Liu Zhanchuan,Yin Haoyuan,Guo Zhenjie,Luo Qi
Cell biology international
Atherosclerosis (AS) is one of the most common chronic inflammatory diseases and a major cause of morbidity and mortality. However, the underlying molecular mechanisms of the progression of AS are still largely unknown. Increasing evidence has demonstrated that long noncoding RNAs (lncRNAs) play important roles in a variety of biological processes and the physiological and pathological progression of human diseases. In this study, we aimed to explore the role and underlying molecular mechanism of lncRNA MEG3 in Raw264.7 cells treated with oxidized low-density lipoprotein (ox-LDL). First, we found that ox-LDL inhibited the cell viability and proliferation, increased TNFα and IL1β secretion and induced the apoptosis of Raw264.7 cells. Second, we demonstrated that ox-LDL upregulated MEG3 expression and that knockdown of MEG3 inhibited the action of ox-LDL in Raw264.7 cells. Third, we showed that MEG3 sponged miR-204 in Raw264.7 cells treated with ox-LDL. Fourth, we demonstrated that miR-204 regulated the expression of cyclin-dependent kinase inhibitor 2A (CDKN2A) in Raw264.7 cells treated with ox-LDL. Finally, we revealed that MEG3 exerted its function via the regulation of the MEG3/miR-204/CDKN2A regulatory axis in Raw264.7 cells treated with ox-LDL. In summary, our study identified the role of the MEG3/miR-204/CDKN2A pathway in Raw264.7 cells treated with ox-LDL, revealed a novel regulatory pathway in AS and indicated potential novel characteristic biomarkers and therapeutic targets for AS.
Sestrin1 inhibits oxidized low-density lipoprotein-induced activation of NLRP3 inflammasome in macrophages in a murine atherosclerosis model.
Keping Yang,Yunfeng Sun,Pengzhuo Xiao,Liang Li,Chenhong Xu,Jinghua Mao
European journal of immunology
Macrophages play a crucial role in the progression of atherosclerotic lesions. In the current study, we analyzed the expression and function of sestrin1 (SESN1) in the aorta macrophages in a murine atherosclerosis model. We identified high SESN1 expression in the aorta macrophages in atherosclerotic mice. Using lentivirus-mediated SESN1 overexpression in macrophages, we found that SESN1 inhibited oxidized low-density lipoprotein-induced NLRP3 inflammasome activation in lipopolysaccharide (LPS)-primed macrophages, as evidenced by less ASC-NLRP3 complex formation, lower caspase-1 activation, and lower generation of mature IL-1β. Besides, SESN1 impeded oxidized low-density lipoprotein-induced activation of NK-κB signaling in macrophages. Furthermore, SESN1 suppressed cholesterol crystal-induced NLRP3 inflammasome activation and foam cell formation. Adoptive transfer of SESN1 overexpressing macrophages reduced the expression of pro-inflammatory cytokines in infiltrating macrophages and the whole aorta tissue. Adoptive transfer of SESN1 knockdown macrophages enhanced the expression of pro-inflammatory cytokines in infiltrating macrophages and the whole aorta tissue. Overall, our study sheds light on the significance of SESN1 for macrophage-mediated aorta inflammation.
MicroRNA-761 modulates foam cell formation and inflammation through autophagy in the progression of atherosclerosis.
Wang Chao,Yang Wei,Liang Xiaofei,Song Wei,Lin Jing,Sun Yan,Guan Xiuru
Molecular and cellular biochemistry
Macrophage-derived foam cells formation is the initial stage of atherosclerosis, and lipid-laden macrophage accumulation is also considered as the symbol of unstable plaque. Autophagy is a subcellular process responsible for the degradation of damaged organelles and aggregated proteins in cells (Grootaert in Oxid Med Cell Longev: 7687083, 2018). Macrophage autophagy plays an important role in atherosclerosis under various stress conditions, and microRNAs are involved in this complicated process. The present study was programmed to explore the effects of microRNA-761 on macrophage-derived foam cell formation, focusing on the role of autophagy in this pathological process. The differentiated human THP-1 macrophages were used in the study. THP-1-derived macrophages were treated with miR-761 mimics or inhibitors and cultured with oxidized low-density lipoprotein to mimic the lipid-rich environment in blood vessel. The expression of miR-761 and mRNA levels of IL-1β and IL-18 were analyzed by quantitative real-time PCR. The effect of miR-761 on autophagy was evaluated by the protein levels of Beclin1, p62/SQSTM1, microtubule-associated protein light chain 3, mammalian target of rapamycin (mTOR), and unc-51-like autophagy activating kinase 1 (ULK1), determined by immunoblot and autophagic flux detected by fluorescent staining. The secretion of IL-1β and IL-18 was tested by enzyme-linked immunosorbent reaction kit. Lipid accumulation in foam cells was detected by oil red "O" staining. We demonstrated that miR-761 was able to repress foam cell formation and reduce the production of atherogenic inflammatory cytokines IL-1β and IL-18 in an autophagy-dependent manner in atherosclerosis, possibly via mTOR-ULK1 signaling pathway. In summary, we described an athero-protective function of miR-761 in macrophages incubated with excess ox-LDL and identified an important novel modulator of mTOR signaling and autophagy in macrophage-derived foam cells. This finding may provide a potential target for the prevention and early treatment in high-risk group of atherosclerosis.
Protective role of sirtuin3 against oxidative stress and NLRP3 inflammasome in cholesterol accumulation and foam cell formation of macrophages with ox-LDL-stimulation.
Ding Yue,Gong Weiwei,Zhang Shuping,Shen Jieru,Liu Xiao,Wang Yuqin,Chen Yun,Meng Guoliang
Sirtuin3 (SIRT3) is involved in reactive oxygen species (ROS), cell metabolism, apoptosis and inflammation. However, the exact role of SIRT3 in macrophages during pathophysiological process of atherosclerosis remains unclear. The present study was to investigate the possible effects and mechanisms of SIRT3 on lipid uptake and foam cells transforming in oxidized low-density lipoprotein (ox-LDL)-stimulated macrophages. Compared with wild-type (WT) mice, SIRT3 deficiency further increased foam cell formation and cellular cholesterol accumulation, exacerbated oxidative stress, impaired mitochondrial permeability potential, decreased optic atrophy 1 (OPA1) but enhanced dynamin-related protein 1 (DRP1) expression, and promoted NLR family pyrin domain-containing protein 3 (NLRP3) activation in ox-LDL-stimulated macrophages from SIRT3 knockout (KO) mice. Dihydromyricetin (DMY), a potential compound to enhance SIRT3 expression, significantly inhibited cellular cholesterol accumulation, suppressed foam cell formation, improved mitochondrial function, attenuated oxidative stress, and alleviated NLRP3 activation in ox-LDL-stimulated macrophages. Moreover, above protective effects of DMY was unavailable in macrophages from SIRT3 KO mice. Collectively, the study demonstrated the protective role of SIRT3 against oxidative stress and NLRP3 inflammasome in cholesterol accumulation and foam cell formation of macrophages with ox-LDL-stimulation, which is beneficial to provide novel strategy for atherosclerosis prevention and treatment.
CISD1 protects against atherosclerosis by suppressing lipid accumulation and inflammation via mediating Drp1.
Hua Jinghai,Gao Zhiming,Zhong Shaochun,Wei Bocui,Zhu Jianbing,Ying Ru
Biochemical and biophysical research communications
Atherosclerosis still remains the leading cause of morbidity and mortality worldwide, and deeper understanding of target signaling that protect from the atherosclerosis progression may provide novel therapeutic strategies. CDGSH iron-sulfur domain-containing protein 1 (CISD1) is a protein localized on the outer membrane of mitochondria, and plays key roles in regulating cell death and oxidative stress. However, its potential on atherosclerosis development and the underlying mechanisms are largely unknown. Here, in our study, we found markedly decreased CISD1 expression in lipid-laden THP1 macrophages. Notably, lentivirus (LV)-mediated CISD1 over-expression remarkably ameliorated lipid deposition in macrophages stimulated by ox-LDL. Furthermore, cellular total ROS and mitochondrial ROS generation, and impairment of mitochondrial membrane potential (MMP) were highly induced by ox-LDL in THP1 cells, while being considerably reversed upon CISD1 over-expression. Inflammatory response caused by ox-LDL was also significantly restrained in macrophages with CISD1 over-expression. Mechanistically, we found that CISD1 could interact with dynamin-related protein 1 (Drp1). Intriguingly, CISD1-improved mitochondrial dysfunction and inflammation in ox-LDL-treated macrophages were strongly abolished by Drp1 over-expression, indicating that Drp1 suppression might be necessary for CISD1 to perform its protective effects in vitro. In high fat diet (HFD)-fed apolipoprotein E-deficient (ApoE) mice, tail vein injection of lentiviral vector expressing CISD1 remarkably decreased atherosclerotic lesion area, serum LDL cholesterol levels and triglyceride contents. Inflammatory response, cellular total and mitochondrial ROS production, and Drp1 expression levels in aorta tissues were also dramatically ameliorated in HFD-fed ApoE mice, contributing to the inhibition of atherosclerosis in vivo. Therefore, improving CISD1 expression may be a novel therapeutic strategy for atherosclerosis treatment.
The selective NLRP3 inhibitor MCC950 hinders atherosclerosis development by attenuating inflammation and pyroptosis in macrophages.
Zeng Wenyun,Wu Danbin,Sun Yingxin,Suo Yanrong,Yu Qun,Zeng Miao,Gao Qing,Yu Bin,Jiang Xijuan,Wang Yijing
NLRP3 inflammasome is a vital player in macrophages pyroptosis, which is a type of proinflammatory cell-death and takes part in the pathogenesis of atherosclerosis. In this study, we used apoE mice and ox-LDL induced THP-1 derived macrophages to explore the mechanisms of MCC950, a selective NLRP3 inhibitor in treating atherosclerosis. For the in vivo study, MCC950 was intraperitoneal injected to 8-week-old apoE mice fed with high-fat diet for 12 weeks. For the in vitro study, THP-1 derived macrophages were treated with ox-LDL and MCC950 for 48 h. MCC950 administration reduced plaque areas and macrophages contents, but did not improve the serum lipid profiles in aortic root of apoE mice. MCC950 inhibited the activation of NLRP3/ASC/Caspase-1/GSDMD-N axis, and alleviated macrophages pyroptosis and the production of IL-1β and IL-18 both in aorta and in cell lysates. However, MCC950 did not affect the expression of TLR4 or the mRNA levels of NLRP3 inflammasome and its downstream proteins, suggesting that MCC950 had no effects on the priming of NLRP3 inflammasome activation in macrophages. The anti-atherosclerotic mechanisms of MCC950 on attenuating macrophages inflammation and pyroptosis involved in inhibiting the assembly and activation of NLRP3 inflammasome, rather than interrupting its priming.
Silencing of IGF2BP1 restrains ox-LDL-induced lipid accumulation and inflammation by reducing RUNX1 expression and promoting autophagy in macrophages.
Journal of biochemical and molecular toxicology
Atherosclerosis (AS) is a chronic inflammatory disease with the formation and accumulation of macrophage-derived foam cells in the subendothelial space of blood vessels as one major characteristic. Insulin-like growth factor 2 messenger RNA (mRNA) binding protein 1 (IGF2BP1) is an RNA-binding factor and its elevation has been reported to be associated with macrophage infiltration into the atherosclerotic vascular wall. This study aims to investigate the roles of IGF2BP1 in AS-associated foam cell formation. Herein, ApoE-/- mice fed with high-fat diet developed atherosclerotic lesions in the aorta, where IGF2BP1 expression was upregulated and autophagy was impaired. IGF2BP1 expressed in F4/80+ macrophages and coexisted with p62. In vitro, IGF2BP1 expression was upregulated in RAW264.7 macrophages exposed to oxidized low-density lipoprotein (ox-LDL) (100 μg/ml). Interestingly, silencing of IGF2BP1 ameliorated ox-LDL-induced lipid accumulation and inflammation, and enhanced autophagic flux in macrophages. Furthermore, the expression of RUNX family transcription factor 1 (RUNX1), a gene that is able to inhibit autophagy in multiple cell types, was elevated in atherosclerotic aortas and in ox-LDL-treated macrophages. In addition, RNA immunoprecipitation results revealed that IGF2BP1 is bound to RUNX1 mRNA. Alterations induced by IGF2BP1 knockdown in ox-LDL-treated macrophages were abolished by RUNX1 overexpression. Furthermore, after autophagy inhibitor 3-methyladenine administration, silencing of IGF2BP1-reduced lipid accumulation and inflammation were recovered in RAW264.7 cells. In summary, our study demonstrated that silencing of IGF2BP1 restrained ox-LDL-induced lipid accumulation and inflammation by reducing RUNX1 expression and facilitating autophagy in macrophages. IGF2BP1/RUNX1 axis may be considered as a potential therapeutic target in AS.
MiR-181a inhibits vascular inflammation induced by ox-LDL via targeting TLR4 in human macrophages.
Du Xian-Jin,Lu Jing-Min,Sha Yin
Journal of cellular physiology
Atherosclerosis is a kind of chronic inflammation disease with lipid accumulation in in blood vessel linings. Increasing evidence has reported that microRNAs can exert crucial roles in atherosclerosis. In previous study, miR-181a has been implicated to be abnormally expressed in atherosclerosis mice, however its detailed function in atherosclerosis remains uninvestigated. Hence, in our current study, we focused on the biological role of miR-181a in atherosclerosis progression. Ox-LDL has been commonly identified as an important atherosclerosis regulator. We observed that ox-LDL induced THP-1 cell apoptosis dose-dependently and time- dependently. Meanwhile, 25 µg/ml ox-LDL can promote foam cell formation and increased miR-181a expression significantly. CD36 has been involved in atherosclerosis progression and it was found that overexpression of miR-181a inhibited its protein levels. Moreover, miR-181a mimics repressed foam cell formation, TC and TG levels induced by ox-LDL dramatically. In addition, miR-181a mimics were able to reverse THP-1 cell apoptosis, increased IL-6, IL-1β, and TNF-α protein expression triggered by 25 µg/ml ox-LDL. TLR4 has been linked to various inflammation-associated diseases. In our present study, TLR4 was indicated as miR-181a target and the binding correlation between them was validated by dual-luciferase reporter assay. In conclusion, these results improves the understanding of atherosclerosis modulated by miR-181a/TLR4 and can contribute to development of new approaches for atherosclerosis.
Y-box binding protein 1 regulates ox-LDL mediated inflammatory responses and lipid uptake in macrophages.
Cao Xueming,Zhu Na,Li Li,Zhang Yuwei,Chen Yan,Zhang Jing,Li Jiang,Gao Chuanyu
Free radical biology & medicine
AIMS:Y-box protein 1 (YB1) is a key regulator of inflammatory mediators. However, the roles of YB1 in oxidized low-density lipoprotein (ox-LDL)-induced macrophage inflammation and lipid uptake remain less understood. Thus, we explored the roles of YB1 in ox-LDL-induced macrophage inflammation and lipid uptake and its underlying molecular mechanisms. METHODS:An ox-LDL-induced atherosclerosis (AS) model was used in this study. Western blotting, RT-PCR, immunofluorescence, ELISA, dil-ox-LDL staining, a dual-luciferase reporter assay, RNA-binding protein immunoprecipitation (RIP) and in vivo experiments were used to detect each target. RESULTS:ox-LDL downregulates YB1 expression in THP-1-derived macrophages and human monocyte-derived macrophages (hMDMs) via the NF-κB pathway. Downregulation of YB1 is facilitated by lipid uptake in macrophages, and CD36 is involved in this process. Furthermore, YB1 suppresses CD36 protein levels by directly binding to the coding sequence of the CD36 gene to promote CD36 mRNA decay but does not affect its mRNA transcription. Additionally, YB1 knockdown enhances the inflammatory response and lipid deposition via the NF-κB pathway in vivo. CONCLUSION:ox-LDL decreases YB1 expression in macrophages, resulting in enhanced inflammatory responses by affecting NF-κB and facilitating lipid uptake by promoting scavenger receptor CD36 mRNA decay.
Rheb (Ras Homolog Enriched in Brain 1) Deficiency in Mature Macrophages Prevents Atherosclerosis by Repressing Macrophage Proliferation, Inflammation, and Lipid Uptake.
Zhang Qinghai,Hu Jie,Wu Yan,Luo Hairong,Meng Wen,Xiao Bo,Xiao Xianzhong,Zhou Zhiguang,Liu Feng
Arteriosclerosis, thrombosis, and vascular biology
OBJECTIVE:Macrophage foam cell formation is an important process in atherosclerotic plaque development. The small GTPase Rheb (Ras homolog enriched in brain 1) regulates endocytic trafficking that is critical for foam cell formation. However, it is unclear whether and how macrophage Rheb regulates atherogenesis, which are the focuses of the current study. Approach and Results: Immunofluorescence study confirmed the colocalization of Rheb in F4/80 and Mac-2 (galectin-3)-labeled lesional macrophages. Western blot and fluorescence-activated cell sorting analysis showed that Rheb expression was significantly increased in atherosclerotic lesions of atherosclerosis-prone (apoE [apolipoprotein E deficient]) mice fed with Western diet. Increased Rheb expression was also observed in oxidized LDL (low-density lipoprotein)-treated macrophages. To investigate the in vivo role of macrophage Rheb, we established mature Rheb (macrophage-specific Rheb knockout) mice by crossing the Rheb floxed mice with F4/80-cre mice. Macrophage-specific knockout of Rheb in mice reduced Western diet-induced atherosclerotic lesion by 32%, accompanied with a decrease in macrophage content in plaque. Mechanistically, loss of Rheb in macrophages repressed oxidized LDL-induced lipid uptake, inflammation, and macrophage proliferation. On the contrary, lentivirus-mediated overexpression of Rheb in macrophages increased oxidized LDL-induced lipid uptake and inflammation, and the stimulatory effect of Rheb was suppressed by the mTOR (mammalian target of rapamycin) inhibitor rapamycin or the PKA (protein kinase A) activator forskolin. CONCLUSIONS:Macrophage Rheb plays important role in Western diet-induced atherosclerosis by promoting macrophage proliferation, inflammation, and lipid uptake. Inhibition of expression and function of Rheb in macrophages is beneficial to prevent diet-induced atherosclerosis.
Tanshinone IIA inhibits the adipogenesis and inflammatory response in ox-LDL-challenged human monocyte-derived macrophages via regulating miR-130b/WNT5A.
Yuan Limei,Li Qinghai,Zhang Zhiguo,Liu Qingle,Wang Xuechen,Fan Lihua
Journal of cellular biochemistry
Atherosclerosis is a kind of chronic cardiovascular disease, characterized by oxidized low-density lipoprotein (ox-LDL) accumulation in macrophage. Tanshinone IIA (Tan), a lipophilic pharmacologically activate compound from Salvia miltiorrhiza Bunge, has been indicated to exert cardioprotective roles. Nevertheless, the biological role of Tan and regulatory mechanism in atherosclerosis are not fully established. In present study, atherosclerosis model was established in THP-1-derived macrophages by treatment of ox-LDL. The adipogenesis was measured by Nile red staining. The expressions of inflammatory factors, microRNA-130b (miR-130b) and WNT5A were measured by quantitative real-time polymerase chain reaction or Western blot. The target association between miR-130b and WNT5A was explored via luciferase activity and RNA immunoprecipitation assay. The results showed that exposure of Tan inhibited ox-LDL-induced adipogenesis and expressions of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-alpha in THP-1-derived macrophages. miR-130b expression was decreased in THP-1-derived macrophages treated by ox-LDL and its overexpression attenuated adipogenesis as well as inflammatory response. miR-130b knockdown reversed the regulatory effect of Tan on adipogenesis and inflammatory response in THP-1-derived macrophages stimulated by ox-LDL. In addition, WNT5A acted as a functional target of miR-130b and inhibited by Tan and miR-130b. As a conclusion, Tan decreased the adipogenesis and inflammatory response by mediating miR-130b and WNT5A, providing a novel theoretical foundation for treatment of atherosclerosis.
MicroRNA-155 promotes the ox-LDL-induced activation of NLRP3 inflammasomes via the ERK1/2 pathway in THP-1 macrophages and aggravates atherosclerosis in ApoE-/- mice.
Yin Ruihua,Zhu Xiaoyan,Wang Jing,Yang Shaonan,Ma Aijun,Xiao Qi,Song Jinyang,Pan Xudong
Annals of palliative medicine
BACKGROUND:Nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome activation can induce the secretion of IL-1β and IL-18 and after promoting the development of atherosclerosis. MiR-155 is an important microRNA that modulates inflammation in atherosclerosis, but the role of miR-155 in the regulation of the NLRP3 inflammasome is still unknown. METHODS:The atherosclerosis model was set up using ApoE-/- mice, and the lentiviral vector (LV) was used to interfere the expression of miR-155. HE stains was used for plaque morphology, immunohistochemistry (IHC) and western blot were used for protein expression quantification. We used oxidized low-density lipoprotein (ox-LDL) to incubate PMA-preprocessed THP-1 macrophages and detected NLRP3 inflammasome activation and ERK1/2 phosphorylation by western blot and Enzyme-linked immunosorbent assay. RESULTS:HE stains showed that the intravascular plaques in the miR-155-up group were remarkably increased, compared with negative control (NC) group. Results of IHC showed that the expression of caspase-1 and IL-1β in the miR-155-up group was the highest of four groups, consist with the Western blot analysis. The results of in vitro experiment show that ox-LDL promoted NLRP3 inflammasome activation and ERK1/2 phosphorylation. Blocking the ERK1/2 pathway could inhibit ox-LDL-induced NLRP3 inflammasome activation. Moreover, we found that the overexpression of miR-155 promoted the activation of the ox-LDL-induced NLRP3 inflammasome, which could also be blocked by the ERK inhibitor U0126. CONCLUSIONS:MiR-155 aggravates the carotid AS lesion in ApoE-/- mice and exerts a regulatory effect on NLRP3 inflammasome activation in ox-LDL-induced macrophages via the ERK1/2 pathway.
Orientin suppresses oxidized low-density lipoproteins induced inflammation and oxidative stress of macrophages in atherosclerosis.
Li Chunmeng,Cai Chanchun,Zheng Xiangjian,Sun Jun,Ye Liou
Bioscience, biotechnology, and biochemistry
Atherosclerosis is a main reason for peripheral vascular disease. The present study aims to investigate the effects of macrophage foam cells which is an initial part in atherosclerosis. RAW 264.7 were treated with 80 μg/mL oxidized low-density lipoproteins (ox-LDL) to mimic atherosclerosis . Orientin, a flavonoid from plants, inhibited ox-LDL induced TNFα, IL-6, IL-1β expression increase. In addition, Orientin also can inhibit the emergence of ox-LDL-induced lipid droplets. The scavenger receptor CD 36 of ox-LDL was significantly downregulated after the treatment of orientin. Inhibition of ROS generation and increasing of eNOS expression by Orientin treatment was used to show the alteration of oxidative stress. Moreover, the expression levels of Angiopoietin-like 2 (angptl2) and NF-κB were significantly upregulated after cells induced by ox-LDL, whereas orientin significantly reversed the effects of ox-LDL. Orientin inhibited ox-LDL-induced inflammation and oxidative stress, and CD36 may be the key regulator during Orientin action.
Long Non-Coding RNAs Link Oxidized Low-Density Lipoprotein With the Inflammatory Response of Macrophages in Atherogenesis.
Yan Youyou,Song Dandan,Wu Junduo,Wang Junnan
Frontiers in immunology
Atherosclerosis is characterized as a chronic inflammatory response to cholesterol deposition in arteries. Low-density lipoprotein (LDL), especially the oxidized form (ox-LDL), plays a crucial role in the occurrence and development of atherosclerosis by inducing endothelial cell (EC) dysfunction, attracting monocyte-derived macrophages, and promoting chronic inflammation. However, the mechanisms linking cholesterol accumulation with inflammation in macrophage foam cells are poorly understood. Long non-coding RNAs (lncRNAs) are a group of non-protein-coding RNAs longer than 200 nucleotides and are found to regulate the progress of atherosclerosis. Recently, many lncRNAs interfering with cholesterol deposition or inflammation were identified, which might help elucidate their underlying molecular mechanism or be used as novel therapeutic targets. In this review, we summarize and highlight the role of lncRNAs linking cholesterol (mainly ox-LDL) accumulation with inflammation in macrophages during the process of atherosclerosis.
miRNA-mediated macrophage behaviors responding to matrix stiffness and ox-LDL.
Li Jing,Wang Sufang,Li Yuhui,Zhang Nu,Gribskov Michael,Zhang Xi,Lin Min,Shao Dongyan,Zhang Chen,Dai Liangliang,Qin Chuanguang,Duan Xianglong,Li Juntang,Xu Feng,Yang Hui
Journal of cellular physiology
Atherosclerosis is one of the leading causes of morbidity and mortality, mainly due to the immune response triggered by the recruitment of monocytes/macrophages in the artery wall. Accumulating evidence have shown that matrix stiffness and oxidized low-density lipoproteins (ox-LDL) play important roles in atherosclerosis through modulating cellular behaviors. However, whether there is a synergistic effect for ox-LDL and matrix stiffness on macrophages behavior has not been explored yet. In this study, we developed a model system to investigate the synergistic role of ox-LDL and matrix stiffness on macrophage behaviors, such as migration, inflammatory and apoptosis. We found that there was a matrix stiffness-dependent behavior of monocyte-derived macrophages stimulated with ox-LDL. What's more, macrophages were more sensitive to ox-LDL on the stiff matrices compared to cells cultured on the soft matrices. Through next-generation sequencing, we identified miRNAs in response to matrix stiffness and ox-LDL and predicted pathways that showed the capability of miRNAs in directing macrophages fates. Our study provides a novel understanding of the important synergistic role of ox-LDL and matrix stiffness in modulating macrophages behaviors, especially through miRNAs signaling pathways, which could be potential key regulators in atherosclerosis and immune-targeted therapies.
Macrophage-derived myeloid differentiation protein 2 plays an essential role in ox-LDL-induced inflammation and atherosclerosis.
Chen Taiwei,Huang Weijian,Qian Jinfu,Luo Wu,Shan Peiren,Cai Yan,Lin Ke,Wu Gaojun,Liang Guang
BACKGROUND:Atherosclerosis is a chronic inflammatory disease. Although Toll-like receptor 4 (TLR4) has been involved in inflammatory atherosclerosis, the exact mechanisms by which oxidized-low-density lipoproteins (ox-LDL) activates TLR4 and elicits inflammatory genesis are not fully known. Myeloid differentiation factor 2 (MD2) is an extracellular molecule indispensable for lipopolysaccharide recognition of TLR4. METHOD:ApoeMd2 mice and pharmacological inhibitor of MD2 were used in this study. We also reconstituted Apoe mice with either Apoe or ApoeMd2 marrow-derived cells. Mechanistic studies were performed in primary macrophages, HEK-293T cells, and cell-free system. FINDING:MD2 levels are elevated in atherosclerotic lesion macrophages, and MD2 deficiency or pharmacological inhibition in mice reduces the inflammation and stunts the development of atherosclerotic lesions in Apoe mice fed with high-fat diet. Transfer of marrow-derived cells from Apoe-Md2 double knockout mice to Apoe knockout mice confirmed the critical role of bone marrow-derived MD2 in inflammatory factor induction and atherosclerosis development. Mechanistically, we show that MD2 does not alter ox-LDL uptake by macrophages but is required for TLR4 activation and inflammation via directly binding to ox-LDL, which triggers MD2/TLR4 complex formation and TLR4-MyD88-NFκB pro-inflammatory cascade. INTERPRETATION:We provide a mechanistic basis of ox-LDL-induced macrophage inflammation, illustrate the role of macrophage-derived MD2 in atherosclerosis, and support the therapeutic potential of MD2 targeting in atherosclerosis-driven cardiovascular diseases. FUNDING:This work was supported by the National Key Research Project of China (2017YFA0506000), National Natural Science Foundation of China (21961142009, 81930108, 81670244, and 81700402), and Natural Science Foundation of Zhejiang Province (LY19H020004).
GAS5 knockdown suppresses inflammation and oxidative stress induced by oxidized low-density lipoprotein in macrophages by sponging miR-135a.
Zhang Yunyan,Lu Xianben,Yang Minjun,Shangguan Jiaolin,Yin Yanping
Molecular and cellular biochemistry
A large number of long non-coding RNAs have been confirmed to play vital roles in regulating various biological processes. Abnormal expression of growth arrest-specific transcript 5 (GAS5) is reported to be involved in the development of atherosclerosis (AS). This work is to explore the detailed mechanism underling how GAS5 regulates AS progression. We found that the abundance of GAS5 was markedly increased, and miR-135a was decreased in AS patient serums and ox-LDL-induced human THP-1 cells dose and time dependently. Interference of GAS5 suppressed inflammation and oxidative stress induced by ox-LDL in THP-1 cells. Mechanistically, GAS5 acted as a molecular sponge of microRNA-135a (miR-135a). Rescue assays indicated that knockdown of miR-135a partially rescued small interference RNA for GAS5-inhibited inflammatory cytokines release and oxidative stress in ox-LDL-triggered THP-1 cells. In conclusion, the absence of GAS5-inhibited inflammatory response and oxidative stress induced by ox-LDL in THP-1 cells via sponging miR-135a, providing a deep insight into the molecular target for AS treatment.
Reduced SULT2B1b expression alleviates ox-LDL-induced inflammation by upregulating miR-148-3P via inhibiting the IKKβ/NF-κB pathway in macrophages.
Yin Mengzhuo,Lu Jianwen,Guo Zhongzhou,Zhang Yanan,Liu Jichen,Wu Tongwei,Guo Kai,Luo Tiantian,Guo Zhigang
Atherosclerosis is a lipid-driven chronic inflammatory disease in which lipid-laden macrophage foam cells lead to inflamed lesions in arteries. Previous studies have proven that sulfotransferase 2B1b (SULT2B1b) has several roles in the regulation of lipid metabolism and the inflammatory response. However, little is known about the functions of SULT2B1b in ox-LDL-induced inflammation in macrophages. In this study, after treatment with either ox-LDL alone or combined with transfection of siRNAs targeting SULT2B1b, IL-6, TNF-α, NF-κB, IKKβ and IκB mRNA and protein expression were determined in Raw264.7 cells by real-time PCR and Western blot, respectively. The proliferative capacity was determined by EdU staining and Cell Counting Kit-8. Our data demonstrated that SULT2B1b knockdown could reduce phosphorylated NF-κB levels and downregulate IKKβ protein levels. Additionally, IκB levels were increased and the proliferation of ox-LDL stimulated cells was inhibited after SULT2B1b silencing. Downregulation of SULT2B1b expression was found to upregulate miR-148a-3p expression by microarray assay, while IKKβ was a miR-148a-3p target gene. Our study suggests that SULT2B1b knockdown could promote miR148a-3p expression and inhibit activation of the IKKβ/NF-κB signalling pathway, which suppressed the inflammatory response in macrophages. Therefore, targeting the SULT2B1b gene might be potentially beneficial for atherosclerosis prevention by decreasing the inflammatory response.
Suppression of PAPP-A mitigates atherosclerosis by mediating macrophage polarization via STAT3 signaling.
Wang Guodong,Liu Xuegang,Li Xia,Zhao Yunbo
Biochemical and biophysical research communications
Pregnancy-associated plasma protein-A (PAPP-A), a type of metalloproteinase in the insulin-like growth factor (IGF) system, has been implicated in atherosclerosis progression, but its function and mechanism in atherosclerosis is not fully understood. The study was performed to further explore the effects of PAPP-A on inflammation, macrophage polarization and atherosclerosis. In mouse macrophages stimulated by oxidized low-density lipoprotein (ox-LDL), PAPP-A expression was significantly increased. Its knockdown markedly mitigated inflammatory response and polarized macrophages to an M2-like phenotype in RAW264.7 cells upon ox-LDL treatment. Additionally, ox-LDL-induced activation of nuclear factor-κB (NF-κB) signaling pathway was dramatically restricted by PAPP-A knockdown in macrophages. However, JAK2/STAT3 activation was significantly up-regulated in RAW264.7 cells with PAPP-A inhibition after ox-LDL treatment. Importantly, we found that PAPP-A knockdown-induced polarization of M2-like phenotype in macrophages was mainly dependent on STAT3 activation. Clinical studies showed that serum PAPP-A levels were higher in patients with coronary artery disease (CAD) than that of healthy individuals. Apolipoprotein E-knockout (ApoE) mice with high fat diet (HFD)-induced atherosclerosis exhibited higher expression of PAPP-A in aortas, which was mainly colocalized with F4/80. Subsequently, we found that PAPP-A deficiency greatly alleviated plaque formation, lesion burden and collagen accumulation in HFD-fed ApoE mice. Consistent with in vitro macrophage phenotype, PAPP-A reduced F4/80 expression, NF-κB activation and inflammatory response, while improved janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling and polarized macrophages to an M2-like phenotype in aortas of ApoE mice after HFD feeding. In conclusion, these findings identified PAPP-A as a positive regulator of atherosclerosis by regulating macrophage polarization via STAT3 signal, and thus could be considered as a potential therapeutic target for atherosclerosis treatment.
CircTM7SF3 contributes to oxidized low-density lipoprotein-induced apoptosis, inflammation and oxidative stress through targeting miR-206/ASPH axis in atherosclerosis cell model in vitro.
Wang Xiaojuan,Bai Ming
BMC cardiovascular disorders
BACKGROUND:Atherosclerosis (AS) is a chronic inflammatory disorder. The aim of our study was to explore the role of circular RNA (circRNA) transmembrane 7 superfamily member 3 (circTM7SF3) in AS progression. METHODS:Experiments were conducted using oxidized low-density lipoprotein (ox-LDL)-induced THP-1-derived macrophages and differentiated human monocyte-derived macrophages (hMDMs). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of circTM7SF3, its linear form TM7SF3, microRNA-206 (miR-206) and aspartyl (asparaginyl) β-hydroxylase (ASPH) messenger RNA (mRNA). Cell viability and apoptosis were examined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. Cell inflammation was analyzed by measuring the production of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) using enzyme-linked immunosorbent assay (ELISA) kits. Cell oxidative stress was assessed through analyzing the levels of oxidative stress markers using their corresponding commercial kits. Dual-luciferase reporter assay and RNA-pull down assay were used to confirm the interaction between miR-206 and circTM7SF3 or ASPH. The protein level of ASPH was examined by Western blot assay. RESULTS:CircTM7SF3 level was markedly increased in the serum samples of AS patients and ox-LDL-induced THP-1-derived macrophages compared with their matching counterparts. ox-LDL induced-damage in THP-1 cells was partly attenuated by the interference of circTM7SF3. MiR-206 was a downstream molecular target of circTM7SF3. Si-circTM7SF3-mediated effects in ox-LDL-induced THP-1-derived macrophages were partly ameliorated by the addition of anti-miR-206. MiR-206 directly interacted with ASPH mRNA. CircTM7SF3 silencing reduced the expression of ASPH partly through up-regulating miR-206 in THP-1-derived macrophages. ASPH overexpression partly counteracted the effects induced by miR-206 overexpression in ox-LDL-induced THP-1-derived macrophages. CONCLUSION:CircTM7SF3 contributed to ox-LDL-induced injury in AS cell model through up-regulating the expression of ASPH via targeting miR-206.
ZBTB20 Positively Regulates Oxidative Stress, Mitochondrial Fission, and Inflammatory Responses of ox-LDL-Induced Macrophages in Atherosclerosis.
Tao Jun,Qiu Junxiong,Lu Liuyi,Zhang Lisui,Fu Yuan,Wang Meng,Han Jingjun,Shi Maomao,Li Ling,Zhao Zongkai,Wei Feng,Wang Chao,Zhang Haifeng,Liang Shi,Zheng Junmeng
Oxidative medicine and cellular longevity
Atherosclerosis (AS) is one of the most serious and common cardiovascular diseases affecting human health. AS is featured by the accumulation of plaques in vessel walls. The pathophysiology of AS is relevant in the low-density lipoprotein (LDL) uptake by macrophages, as well as the conversion of macrophages to foam cells. However, the mechanisms about how macrophages regulate AS have not been fully elucidated. In this study, we aimed to illuminate the roles of ZBTB20 and to excavate the underlying regulative mechanisms of ZBTB20 in AS. The microarray analysis revealed that ZBTB20 was a hub gene in the oxidative stress and inflammatory responses induced by oxidized LDL (ox-LDL) in AS. Correspondingly, our validation studies showed that ZBTB20 increased in either the human atherosclerotic lesion or the ox-LDL-stimulated macrophages. Moreover, the knockdown of ZBTB20 decreased M1 polarization, suppressed the proinflammatory factors, inhibited mitochondrial fission, and reduced the oxidative stress level of macrophages induced by ox-LDL. The mechanistic studies revealed that the ZBTB20 knockdown suppressed NF-B/MAPK activation and attenuated the mitochondrial fission possibly via regulating the nucleus translocation of NRF2, a pivotal transcription factor on redox homeostasis. Our studies showed that the sh-ZBTB20 adenovirus injection could reduce the progression of AS in apolipoprotein E-deficient (ApoE) mice. All in all, these results suggested that ZBTB20 positively regulated the oxidative stress level, mitochondrial fission, and inflammatory responses of macrophages induced by ox-LDL, and the knockdown of ZBTB20 could attenuate the development of AS in ApoE mice.
Pim-2 kinase inhibits inflammation by suppressing the mTORC1 pathway in atherosclerosis.
Liao Minqi,Hu Feng,Qiu Zhiqiang,Li Juan,Huang Chahua,Xu Yan,Cheng Xiaoshu
BACKGROUND:Inflammatory immunity theory has raised considerable concern in the pathogenesis of atherosclerosis. Proviral integration site of murine 2 (Pim-2) kinases functions in apoptosis pathways and the anti-inflammatory response. Here, we investigated whether Pim-2 kinase inhibits atherosclerotic inflammation by suppressing the mTORC1 pathway. METHODS:An atherosclerosis animal model was established by feeding ApoE mice a high-fat diet. THP-1-derived macrophages were subjected to ox-LDL (50 μg/ml, 24h) conditions to mimic the conditions. RESULT:The protein expression of Pim-2 was upregulated in ox-LDL-treated THP-1-derived macrophages and an atherosclerotic mouse model. Additionally, ox-LDL upregulated the protein expression of p-mTOR, p-S6K1 and p-4EBP1, intracellular lipid droplets, free cholesterol and cholesterylester and the mRNA expression of inflammatory cytokines, including IL-6, MCP-1, TLR-4 and TNF-α, in THP-1-derived macrophages. Functionally, overexpressed Pim-2 (Pim-2 OE) attenuated atherosclerotic inflammation associated with the mTORC1 signaling pathway and , whereas knocked down Pim-2 (Pim-2 KD) markedly promoted atherosclerotic inflammation associated with upregulation of the mTORC1 signaling pathway. The plaque areas and lesions in the whole aorta and aortic root sections were alleviated in ApoE mice with Pim-2 OE, but aggravated by Pim-2 KD. Additionally, an mTOR agonist (MHY1485) counteracted the anti-inflammatory effect of Pim-2 in ox-LDL-treated THP-1-derived macrophages after Pim-2 OE, whereas rapamycin rescued atherosclerotic inflammation in ox-LDL-treated THP-1-derived macrophages after Pim-2 KD. Furthermore, si-mTOR and si-Raptor alleviated the atherosclerotic proinflammatory effect in ox-LDL-treated THP-1-derived macrophages in a the background of Pim-2 KD. CONCLUSIONS:These results indicated that Pim-2 kinase inhibits atherosclerotic inflammation by suppressing the mTORC1 pathway.
CircSCAP Aggravates Oxidized Low-density Lipoprotein-induced Macrophage Injury by Upregulating PDE3B by miR-221-5p in Atherosclerosis.
He Qian,Shao Dandan,Hao Shengyun,Yuan Yuan,Liu Hanling,Liu Fuyi,Mu Qiong
Journal of cardiovascular pharmacology
ABSTRACT:Atherosclerosis (AS) is a major risk factor for cardiovascular disease, in which circular RNAs play important regulatory roles. This research aimed to explore the biological role of circular RNA Sterol Regulatory Element Binding Transcription Factor Chaperone (circSCAP) (hsa_circ_0001292) in AS development. Real-time PCR or Western blot assay was conducted to analyze RNA or protein expression. Cell proliferation and apoptosis were analyzed by CCK-8 assay and flow cytometry. The levels of lipid accumulation-associated indicators and oxidative stress factors were detected using commercial kits. The levels of inflammatory cytokines were examined using enzyme-linked immunosorbent assay. Intermolecular interaction was verified by dual-luciferase reporter analysis or RNA pull-down analysis. CircSCAP and phosphodiesterase 3B (PDE3B) levels were elevated, whereas the miR-221-5p level was decreased in patients with AS and oxidized low-density lipoprotein (ox-LDL)-induced THP-1 cells. CircSCAP absence suppressed lipid deposition, inflammation, and oxidative stress in ox-LDL-induced THP-1 cells. MiR-221-5p was a target of circSCAP, and anti-miR-221-5p largely reversed si-circSCAP-induced effects in ox-LDL-induced THP-1 cells. PDE3B was a target of miR-221-5p, and PDE3B overexpression largely counteracted miR-221-5p accumulation-mediated effects in ox-LDL-induced THP-1 cells. NF-κB signaling pathway was regulated by circSCAP/miR-221-5p/PDE3B axis in ox-LDL-induced THP-1 cells. In conclusion, circSCAP facilitated lipid accumulation, inflammation, and oxidative stress in ox-LDL-induced THP-1 macrophages by regulating miR-221-5p/PDE3B axis.