Target For Treatment Of Atherosclerosis Research Articles

Identification of Macrophage-Associated Novel Drug Targets in Atherosclerosis Based on Integrated Transcriptome Features.

This study explores the pathological mechanisms of atherosclerosis (AS), focusing on the role of macrophages in its formation and development, and potential therapeutic targets. The heterogeneity of the AS single-cell data set GSE131778 was analyzed using Seurat. Tissue sequencing data GSE28829 and GSE43292 were analyzed for immune cell abundance using CIBERSORT. Differential genes were identified, and WGCNA was used to create a coexpression network. Hub genes were identified using MCODE and CytoHubba and analyzed with GO and KEGG enrichment analysis, GSVA, and immune infiltration analysis. DrugBank identified potential drugs, and molecular docking verified drug binding to key targets. Key targets were experimentally validated. Nineteen cell clusters were identified in the GSE131778 data set, classified into ten cell types. Macrophages in AS and normal tissues were identified based on cell abundance. CIBERSORT showed a significant increase in cell cluster 9 in AS samples. Thirty-two hub genes, including CD86, LILRB2, and IRF8, were validated. GO and KEGG analyses indicated Hub genes primarily affect immune functions. GSVA identified 29 significantly increased pathways in AS samples. Immune infiltration analysis revealed a positive correlation between IRF8, CD86, and LILRB2 expression and macrophage content. Molecular docking suggested CD86 as a potential drug target for AS. qRT-PCR confirmed increased IRF8 and CD86 expression. CD86, LILRB2, and IRF8 are highly expressed in foam cell samples, with CD86 forming hydrogen bonds with several AS drugs, indicating CD86 as a promising target for AS treatment.

Candida albicans accelerates atherosclerosis by activating intestinal hypoxia-inducible factor2α signaling

The gut microbiota is closely linked to atherosclerosis. However, the role of intestinal fungi, essential members of the complex microbial community, in atherosclerosis is poorly understood. Herein, we show that gut fungi dysbiosis is implicated in patients with dyslipidemia, characterized by higher levels of Candida albicans (C.albicans), which are positively correlated with plasma total cholesterol and low-density lipoprotein-cholesterol (LDL-C) levels. Furthermore, C.albicans colonization aggravates atherosclerosis progression in a mouse model of the disease. Through gain- and loss-of-function studies, we show that an intestinal hypoxia-inducible factor 2α (HIF-2α)-ceramide pathway mediates the effect of C.albicans. Mechanistically, formyl-methionine, a metabolite of C.albicans, activates intestinal HIF-2α signaling, which drives increased ceramide synthesis to accelerate atherosclerosis. Administration of the HIF-2α selective antagonist PT2385 alleviates atherosclerosis in mice by reducing ceramide levels. Our findings identify a role for intestinal fungi in atherosclerosis progression and highlight the intestinal HIF-2α-ceramide pathway as a target for atherosclerosis treatment.

Circ_0002331 Interacts with ELAVL1 to Improve ox-LDL-Induced Vascular Endothelial Cell Dysfunction via Regulating CCND2 mRNA Stability.

Circular RNAs (circRNAs) have been discovered to serve as vital regulators in atherosclerosis (AS). However, the role and mechanism of circ_0002331 in AS process arestill unclear. Human umbilical vein endothelial cells (HUVECs) were treated with ox-LDL to establish an in vitro model for AS. The expression levels of circ_0002331, Cyclin D2 (CCND2) and ELAVL1 were analyzed by quantitative real-time PCR. Cell proliferation, apoptosis, migration, invasion and angiogenesis were assessed by EdU assay, flow cytometry, transwell assay and tube formation assay. The protein levels of CCND2, ELAVL1, and autophagy-related markers were detected using western blot analysis. IL-8 level was analyzed by ELISA. The relationship between ELAVL1 and circ_0002331 or CCND2 was analyzed by RIP assay and RNA pull-down assay. Moreover, FISH assay was used to analyze the co-localization of ELAVL1 and CCND2 in HUVECs. Our data showed that circ_0002331 was obviously downregulated in AS patients and ox-LDL-induced HUVECs. Overexpression of circ_0002331 could promote proliferation, migration, invasion and angiogenesis, while inhibit apoptosis, autophagy and inflammation in ox-LDL-induced HUVECs. Furthermore, CCND2 was positively regulated by circ_0002331, and circ_0002331 could bind with ELAVL1 to promote CCND2 mRNA stability. Besides, CCND2 overexpression suppressed ox-LDL-induced HUVECs dysfunction, and its knockdown also reversed the regulation of circ_0002331 on ox-LDL-induced HUVECs dysfunction. In conclusion, circ_0002331 might be a potential target for AS treatment, which could improve ox-LDL-induced dysfunction of HUVECs via regulating CCND2 by binding with ELAVL1.

LPS adsorption and inflammation alleviation by polymyxin B-modified liposomes for atherosclerosis treatment.

Chronic inflammation is critical in the onset and progression of atherosclerosis (AS). The lipopolysaccharide (LPS) level in the circulation system is elevated in AS patients and animal models, which is correlated with the severity of AS. Inspired by the underlying mechanism that LPS could drive the polarization of macrophages toward the M1 phenotype, aggravate inflammation, and ultimately contribute to the exacerbation of AS, LPS in the circulation system was supposed to be the therapeutic target for AS treatment. In the present study, polymyxin (PMB) covalently conjugated to PEGylated liposomes (PLPs) were formulated to adsorb LPS through specific interactions between PMB and LPS. Invitro, the experiments demonstrated that PLPs could adsorb LPS, reduce the polarization of macrophages to M1 phenotype and inhibit the formation of foam cells. Invivo, the study revealed that PLPs treatment reduced the serum levels of LPS and pro-inflammatory cytokines, decreased the proportion of M1-type macrophages in AS plaque, stabilized AS plaque, and downsized the plaque burdens in arteries, which eventually attenuated the progression of AS. Our study highlighted LPS in the circulation system as the therapeutic target for AS and provided an alternative strategy for AS treatment.

Paeonol Attenuates the Endothelial-to-Mesenchymal Transition Induced by TGF-β1 in Human Umbilical Vein Endothelial Cells through ALK5- Smad2/3 Signaling Pathway.

Paeonol (Pae), the main active compound of the root of Paeonia albiflora, is efficacious in treating atherosclerosis (AS). Endothelial dysfunction is throughout the pathological progression of AS. It is expected that inhibition of Endothelial-to-mesenchymal transition (EndMT) will be a key target for AS treatment. In this study, we investigated the molecular mechanism of the regulatory effect of Pae on EndMT in human umbilical vein endothelial cells (HUVECs). Cell cytotoxicity, proliferation, and migration were detected by CCK-8, the wound healing assay, and EdU staining, respectively. The protein expressions were measured by Western blot or immunofluorescence staining. Immunofluorescence staining was performed to indicate endothelial cells undergoing EndMT in ApoE-/- mice. In vitro TGF-β1-induced EndMT assays were performed in HUVECs and the effect of Pae was explored. We demonstrated that Pae could improve induced TGF-β1-EndMT in vivo and in vitro. Mechanism study revealed that Pae directly bonds to the activin-like kinase 5 (ALK5, also known as TGFβ type I receptor), inhibited downstream Smad2/3 phosphorylation, and thus alleviated EndMT. Notably, overexpression of ALK5 significantly reversed the inhibitory effect of Pae on EndMT in HUVECs. Our results indicate that ALK5 is a promising druggable target for AS, and pharmacological regulation of ALK5-Smad2/3 signaling pathway with small-molecule holds great potential to benefit AS patients.

Circ_ARHGAP32 acts as miR-665 sponge to upregulate FGF2 to promote ox-LDL induced vascular smooth muscle cells proliferation and migration.

Circular RNA (circRNA) is considered to be an important regulator of human diseases, including atherosclerosis (AS). However, the role of circ_ARHGAP32 in AS formation needs further confirmation. To explore the role of circ_ARHGAP32 in AS formation. Oxidized low density lipoprotein (ox-LDL) was used to treat vascular smooth muscle cells (VSMCs) to mimic AS cell models in vitro. The expression of circ_ARHGAP32, microRNA (miR)-665, and fibroblast growth factor 2 (FGF2) was analyzed by quantitative real-time PCR. VSMCs function was measured by EdU assay, cell counting kit 8 assay and transwell assay. Protein expression was determined using western blot analysis. Dual-luciferase reporter assay and RNA pull-down assay were performed to verify RNA interaction. Circ_ARHGAP32 was highly expressed in AS patients and ox-LDL-induced VSMCs. Knockdown of circ_ARHGAP32 repressed ox-LDL-induced proliferation and migration in VSMCs. Circ_ARHGAP32 sponged miR-665 to positively regulate FGF2. MiR-665 inhibitor reversed the regulation of sh-circ_ARHGAP32 on ox-LDL-induced VSMCs proliferation and migration. MiR-665 also had a suppressive effect on the proliferation and migration of ox-LDL-induced VSMCs, and this effect could be reversed by FGF2 overexpression. Circ_ARHGAP32 might be a potential target for AS treatment, which promoted ox-LDL-induced VSMCs proliferation and migration by regulating miR-665/FGF2 network.

Silencing of Long Noncoding RNA TUG1 Ameliorates Atherosclerosis-Induced Myocardial Injury by Upregulating microRNA-30b-3p and Downregulating Brd4.

Long noncoding RNAs and microRNAs (miRNAs) are emerging biomarkers involved in human diseases, and we focused on the roles of long noncoding RNA taurine upregulated gene 1 (TUG1) and miR-30b-3p in the related mechanisms of atherosclerosis-induced myocardial injury. ApoE-deficient mice were fed with high-fat diet to establish atherosclerotic models and then were subjected to either TUG1 downregulation or miR-30b-3p upregulation treatment. The serum myocardial enzymes, inflammatory biomarkers, pathological changes, intramyocardial macrophage infiltration, and apoptosis of cardiomyocytes in atherosclerotic mice were determined. The expression of TUG1, miR-30b-3p, and bromodomain protein 4 (Brd4) in atherosclerotic models was evaluated. Moreover, the correlations of TUG1, miR-30b-3p, and Brd4 were verified. TUG1 and Brd4 were increased while miR-30b-3p was decreased in atherosclerotic mice. The silenced TUG1 or elevated miR-30b-3p attenuated atherosclerosis-induced myocardial injury mainly by reducing serum myocardial enzyme content and inflammatory response, improving pathological changes, and preventing macrophage infiltration and cardiomyocyte apoptosis in atherosclerotic mice. Mechanistically, TUG1 could competitively bind with miR-30b-3p to prevent the degradation of its target gene Brd4. This study reveals that the silencing of TUG1 ameliorates atherosclerosis-induced myocardial injury by upregulating miR-30b-3p and downregulating Brd4, which may provide novel targets for atherosclerosis treatment.

Exosomal microRNA-16-5p from macrophage exacerbates atherosclerosis via modulating mothers against decapentaplegic homolog 7.

Studies have probed the function of microRNA (miR)-16-5p in the progression of atherosclerosis (AS), while the regulatory function of exosomal miR-16-5p from macrophage on AS remains largely unknown. This study commits to exploring the efficiency of exosomal miR-16-5p from macrophage on AS via modulating mothers against decapentaplegic homolog 7 (SMAD7). Macrophages were cultured and transfected with miR-16-5p antagomir, then, the exosomes from macrophages were extracted. The AS mouse model was established, and miR-16-5p or SMAD7 expression in AS mice was detected. Thereafter, the effects of macrophage-derived exosomes, miR-16-5p or SMAD7 on serum inflammatory response, oxidative stress response, pathological changes and apoptosis in AS mice were observed by immunohistochemical and biochemical analysis. Finally, the binding relation between miR-16-5p and SMAD7 was examined. MiR-16-5p was elevated while SMAD7 was depleted in AS mice. Macrophage-derived exosomes aggravated AS progression via facilitating inflammatory response and oxidative stress, exacerbating pathological changes and increasing cell apoptosis in AS mice; while downregulation of miR-16-5p reversed the exacerbation of AS progression by macrophage-derived exosomes in AS mice. MiR-16-5p targeted SMAD7, and the down-regulated SMAD7 reversed the impacts of depleted miR-16-5p on AS progression. Exosomal miR-16-5p from macrophages aggravates AS progression via downregulating SMAD7 expression. This study provides novel therapeutic targets for AS treatment from the animal level.

Circular RNA testis-expressed 14 overexpression induces apoptosis and suppresses migration of ox-LDL-stimulated vascular smooth muscle cells via regulating the microRNA 6509-3p/thanatos-associated domain-containing apoptosis-associated protein 1 axis

ABSTRACT Atherosclerosis is a severe vascular disorder causing myocardial infarction, stroke, and gangrene. Circular RNA Testis-expressed 14 (hsa_circ_0107197, CircTEX14) is a newly discovered circRNA that may have a critical role in the pathogenesis of atherosclerosis. Here, we aimed to further explore the exact role of circRNA TEX14 in the cardiovascular system. Serum samples of atherosclerosis patients (n = 48) and healthy volunteers (n = 48) were collected to assess circTEX14 expressions. Quantitative reverse transcription-PCR (qRT-PCR), cell proliferation assay, migration assay, cell necrosis assay, Annexin staining, TUNEL assays, RNA immunoprecipitation (RIP) assays, dual-luciferase reporter assays, wound healing assays, and Western blot were performed to examine the roles of circTEX14, miR-6509-3p, and thanatos-associated domain-containing apoptosis-associated protein 1 (THAP1) in ox-LDL-stimulated vascular smooth muscle cells (VSMCs). We found that circTEX14 expressions were decreased and miR-6509-3p expressions were increased in the serum samples of atherosclerosis patients and ox-LDL-stimulated VSMCs. CircTEX14 overexpression inhibited proliferation and migration and enhanced apoptosis of VSMCs. CircTEX14 suppressed miR-6509-3p expressions through direct interaction. MiR-6509-3p or THAP1 knockdown reversed the effects of circTEX14 overexpression on proliferation, migration, and apoptosis of ox-LDL-stimulated VSMCs. In conclusion, circTEX14 inhibited proliferation and enhanced apoptosis via modulating miR-6509-3p/THAP1 in ox-LDL-stimulated VSMCs and might be a useful target for atherosclerosis treatment.

MiR-199a-3p Restrains Foaming and Inflammation by Regulating RUNX1 in Macrophages.

MiR-199a-3p was reported decreased in serum of coronary heart disease patients and human atherosclerotic plaques. This study aims to investigate the roles of miR-199a-3p in atherosclerosis (AS). AS was induced in ApoE-/- mice via high fat diet for 12weeks. Oxidized low density lipoprotein (ox-LDL) was used to induce foaming in RAW264.7 cells. The expression level of miR-199a-3p was decreased in aortas of AS mice and ox-LDL-treated macrophages. Oil red O staining, ELISA, flow cytometry, and western blot results demonstrated that miR-199a-3p mimics restrained ox-LDL-induced lipid accumulation, foaming, and inflammation in RAW264.7 cells, while miR-199a-3p inhibitor played opposite roles. Runt-related transcription factor 1 (RUNX1), a pro-inflammatory factor, was identified as a target of miR-199a-3p, and its expression was downregulated by miR-199a-3p. RUNX1 was increased in macrophages from aortas and peripheral blood of AS mice. Ox-LDL-induced inflammation and lipid accumulation were aggravated by RUNX1, and the effects of miR-199a-3p were antagonized by ectopic expression of RUNX1 in RAW264.7 cells. The phosphorylation of signal transducer and activator of transcription 3 (STAT3) was inhibited by miR-199a-3p and enhanced by RUNX1. In conclusions, we demonstrated that miR-199a-3p alleviated ox-LDL-induced foaming and inflammation by downregulating RUNX1 expression and deactivating STAT3 signaling in macrophages. These findings may provide novel targets for treatment of AS.

Expression and Significance of Programmed Death-1 and Its Ligands in the Accelerated Formation of Atherosclerosis in an Induced Murine Lupus Model.

Atherosclerosis (AS) is a chronic inflammatory disease that occurs in artery walls, which seriously affects the survival and prognosis of patients with systemic lupus erythematosus (SLE). Immune and inflammatory responses have notable effects on all stages of AS. In this study, we modeled SLE combined with AS in vivo via intraperitoneal injection of pristane (2,6,10,14-tetramethylpentadecane) into apolipoprotein E-knockout (ApoE-/- ) mice that had accelerated atherosclerotic lesions compared with wild-type (WT) ApoE-/- mice. In pristane-induced ApoE-/- mice, expression of programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) in peripheral blood and on the surfaces of atherosclerotic lesions significantly increased, and levels of proinflammatory cytokines, namely, interferon-gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) in peripheral blood were elevated. We did not detect expression of programmed death-ligand 2 (PD-L2) in the arterial plaques of either pristane-induced or WT ApoE-/- mice, nor did we observe any significant difference in PD-L2 expression in peripheral blood between the two groups. Taken together, these results suggested that PD-1/PD-L1 signaling pathway might play an important regulatory role in the progression of AS in an induced murine lupus model which implies a potential target for treatment of AS in SLE.

Overexpression of sFlt-1 represses ox-LDL-induced injury of HUVECs by activating autophagy via PI3K/AKT/mTOR pathway.

Soluble fms-like tyrosine kinase-1 (sFlt-1), a circulating antiangiogenic protein, is involved in the pathogenesis of atherosclerosis (AS), and the underlying mechanism is still unclear. Here, we attempted to investigate the mechanism of action of sFlt-1 in AS. Human umbilical vein endothelial cells (HUVECs) were treated with oxidized low density lipoprotein (ox-LDL) to induce cell injury. ox-LDL treatment increased LC3-II/LC3-I ratio, Beclin-1 expression and GFP-LC3 puncta in HUVECs, suggesting that ox-LDL may induce autophagic flux impairment in HUVECs. ox-LDL-treated HUVECs displayed a decrease of sFlt-1 levels. Moreover, ox-LDL treatment reduced cell proliferation and elevated apoptosis in HUVECs, which was abrogated by sFlt-1 overexpression. Up-regulation of sFlt-1 repressed the activity of PI3K/AKT/mTOR signaling pathway and enhanced autophagy in HUVECs following ox-LDL treatment. Additionally, sFlt-1 overexpression-mediated increase of autophagy in ox-LDL-treated HUVECs was abolished by 3-methyladenine (autophagy inhibitor). 3-methyladenine abrogated the impact of sFlt-1 overexpression on proliferation and apoptosis in ox-LDL-treated HUVECs. This work confirmed that overexpression of sFlt-1 activated autophagy by repressing PI3K/Akt/mTOR signaling pathway, and thus alleviated ox-LDL-induced injury of HUVECs. Therefore, this study suggests that sFlt-1 may be a potential target for AS treatment.

LncRNA TP73-AS1 promotes oxidized low-density lipoprotein-induced apoptosis of endothelial cells in atherosclerosis by targeting the miR-654-3p/AKT3 axis

BackgroundAlthough lncRNA TP73-AS1 has been shown to play important roles in various human diseases, its function in atherosclerosis (AS) remains unclear.MethodsHuman aortic endothelial cells (HAECs) were treated with 50 μg/ml oxidized low-density lipoprotein (ox-LDL) to establish an atherosclerotic cell model. The expression of TP73-AS1, miR-654-3p and AKT3 was detected by qRT-PCR. Cell functions were evaluated CCK-8 assay and flow cytometry. The protein levels of apoptosis-related proteins were evaluated by western blot. The binding relationship among TP73-AS1, miR-654-3p and AKT3 was determined by bioinformatics analysis and luciferase reporter assay.ResultsTP73-AS1 was upregulated and miR-654-3p was downregulated in ox-LDL treated HAECs. TP73-AS1 silencing and miR-654-3p mimics decreased the viability and inhibited apoptosis of ox-LDL treated HAECs, decreased the expression levels of c-caspase-9, c-caspase-3 and Bax, and increased Bcl-2 expression. In addition, miR-654-3p inhibitor significantly reversed the inhibitory effects of si-TP73-AS1 on cell viability and apoptosis. TP73-AS1 could positively regulate AKT3 through directly sponging miR-654-3p.ConclusionTP73-AS1 promoted apoptosis of ox-LDL stimulated endothelial cells by targeting the miR-654-3p/AKT3 axis, suggesting that TP73-AS1 might be a potential target for AS treatment.

Circ_CHFR Promotes Platelet-Derived Growth Factor-BB-Induced Proliferation, Invasion, and Migration in Vascular Smooth Muscle Cells via the miR-149-5p/NRP2 Axis.

Circular RNA checkpoint with forkhead and ring finger domains (circ_CHFR) were reported to regulate vascular smooth muscle cell (VSMC) dysfunction during atherosclerosis (AS). However, the molecule mechanism of circ_CHFR in AS remains largely unclear. Human VSMCs (HVSMCs) were exposed to platelet-derived growth factor-BB (PDGF-BB) in vitro. Levels of circ_CHFR, microRNA (miR)-149-5p, and neuropilin 2 (NRP2) were determined using quantitative real-time polymerase chain reaction and western blot. Cell proliferation, migration, and invasion were analyzed using cell counting kit-8, colony formation, flow cytometry, wound healing, and transwell assays. The binding interaction between miR-149-5p and circ_CHFR or NRP2 was investigated using the dual-luciferase reporter and RNA immunoprecipitation assays. Circ_CHFR was elevated in PDGF-BB-induced HVSMCs in a dose-independent manner. Silencing of circ_CHFR reversed PDGF-BB-evoked promotion of cell proliferation, migration and invasion, as well as suppression of cell apoptosis in HVSMCs. Mechanistically, circ_CHFR directly bound to miR-149-5p, and miR-149-5p inhibition attenuated the effects of circ_CHFR knockdown on PDGF-BB-induced HVSMCs. Besides, NRP2 was confirmed to be a target of miR-149-5p, and circ_CHFR could regulate NRP2 expression through sponging miR-149-5p. Moreover, miR-149-5p overexpression abolished PDGF-BB-triggered enhancement of cell proliferation, migration, and invasion by targeting NRP2. Circ_CHFR promoted the proliferation, invasion, and migration of PDGF-BB-induced HVSMCs through miR-149-5p/NRP2 axis, providing a new insight into the pathogenesis of AS and a potential therapeutic target for AS treatment.

MicroRNA-199a-3p Exhibits Beneficial Effects in Asymptomatic Atherosclerosis by Inhibiting Vascular Smooth Muscle Cell Proliferation and Migration.

Atherosclerosis (AS) is a serious healthy burden worldwide, it occurs accompany with the disfunction of vascular smooth muscle cells (VSMCs). MicroRNAs play pivotal role in the pathogenesis of various diseases. This study aimed to investigate the expression and clinical value of miR-199a-3p in patients with asymptomatic AS, and further explore its regulatory role on VSMCs biological function. Quantitative real-time PCR was used to estimate the expression of miR-199a-3p. Correlation of miR-199a-3p with carotid intima-media thickness (CIMT) and C-reactive protein (CRP) was evaluated by Pearson correlation coefficient. A receiver operating characteristic (ROC) curve was plotted to evaluate the diagnostic value of miR-199a-3p. Effects of miR-199a-3p on cell proliferation and migration in VSMCs were analyzed using cell-counting method and Transwell assay. Luciferase reporter assay was performed for the target gene analysis. Serum expression of miR-199a-3p was decreased in asymptomatic AS patients compared with the healthy controls. The negative correlations of miR-199a-3p with CIMT and CRP were obtained. The decreased miR-199a-3p was proved to have diagnostic accuracy with an area under the ROC curve (AUC) of 0.912, and was an independent predictor for the occurrence of asymptomatic AS. In VSMCs, overexpression of miR-199a-3p led to inhibited cell proliferation and migration, while the knockdown of miR-199a-3p resulted in the opposite results. SP1 was proved to be the target gene of miR-199a-3p. Taken together, downregulated expression of miR-199a-3p is a candidate diagnostic biomarker in the patients with asymptomatic AS. Overexpression of miR-199a-3p exists suppressive effects on VSMC proliferation and migration, indicating that miR-199a-3p may be a potential therapeutic target for AS treatment.

Resistin-like molecule beta augments phenotypic modulation of human aortic smooth muscle cell triggered by high glucose

Vascular muscle cells (VSMCs) participate in the pathophysiology of atherosclerosis. Resistin-like molecule beta (Relmβ) contributes to atherosclerosis development by activating macrophage. This study aims to investigate whether Relmβ regulates VSMC phenotypic modulation under high glucose environment. Human aortic vascular smooth muscle cells were cultured and treated with Relmβ in the presence or absence of high glucose. VSMC phenotypic modulation was assessed by expression of related markers. The migration of VSMCs was detected by wound healing assay and transwell assay. The proliferation of VSMCs was measured using CCK-8 assay. In this study, we observed that Relmβ modulated VSMC phenotypic modulation by down-regulating expression of smooth muscle α-actin (α-SMA), smooth muscle myosin heavy chain (SM-MHC), and calponin while up-regulating expression of osteopontin (OPN). Relmβ increased the expression of inflammatory genes in VSMCs. Relmβ also augmented VSMCs migration as well as proliferation. It is worth noting that all the effects of VSMCs were enhanced upon high glucose stimulation. The phosphorylation levels of p38MAPK and ERK1/2 were increased by co-treatment with Relmβ and high glucose. The p38 MAPK pathway inhibitor RWJ64809 and pERK1/2 inhibitor PD98059 significantly inhibited the proliferation of VSMCs induced by Relmβ and high glucose. Our results provide evidence that Relmβ augments phenotypic modulation and migration of human aortic smooth muscle cell induced by high glucose. Relmβ might be a potential target for treatment of atherosclerosis induced by hyperglycemia.

PHACTR1, a pro-atherosclerotic mechanosensitive PPARgamma corepressor in endothelial cells

Abstract Background Numerous genome-wide association studies revealed that SNPs at phosphatase and actin regulator 1 (PHACTR1) locus are strongly correlated with coronary artery disease (CAD). However, the mechanism linking these variants to CAD remains uncertain. Purpose We studied the biological functions and molecular mechanisms of PHACTR1 in atherosclerosis. Methods and results Analysis of GTEx database showed that CAD-related SNPs in PHACTR1 are cis-eQTLs for PHACTR1 in arteries. Therefore, we generated Phactr1 knockout mice and crossed them with apolipoprotein E-deficient (ApoE−/−) mice to induce atherosclerosis by high-fat/high-cholesterol (HF-HC) diet. Phactr1 deficiency significantly inhibited atherosclerosis with decreased inflammatory cell infiltration. Western blot showed that PHACTR1 was restricted to endothelial cells (ECs) in mice. Mechanistically, RNAseq of aortic ECs revealed that the major molecular function of PHACTR1 was transcriptional regulation. PPARγ/RXRα was the top transcription factor, and PPARγ target gene expression substantially increased in Phactr1−/− mice. Moreover, we generated endothelial cell specific Phactr1−/−, ApoE−/− mice and found decreased atherosclerotic plaque area in aortic sinus. In vitro, PHACTR1 associated with PPARγ and inhibited PPARγ transcriptional activity. The inhibitory effect of PHACTR1 on PPARγ required its shuttling from cytosol to nucleus triggered by disturbed flow, a well-established pro-atherosclerotic stimulus. Conclusion Our results identified PHACTR1 as a mechanosensitive corepressor of PPARγ in ECs to promote atherosclerosis. Endothelial PHACTR1 is a potential therapeutic target for atherosclerosis treatment. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Natural Science Foundation of China (NSFC), China Postdoctoral Science Foundation (CPSF)

GAS5 knockdown suppresses inflammation and oxidative stress induced by oxidized low-density lipoprotein in macrophages by sponging miR-135a.

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.

Deubiquitination of CD36 by UCHL1 promotes foam cell formation

Atherosclerosis-associated cardiovascular diseases are main causes leading to high mortality worldwide. Macrophage-derived foam cell formation via uptaking modified lipoproteins is the initial and core step in the process of atherosclerosis. Meanwhile, scavenger receptor is indispensable for the formation of foam cells. UCHL1, a deubiquitinase, has been widely studied in multiple cancers. UCHL1 could be an oncogene or a tumor suppressor in dependent of tumor types. It remains unknown whether UCHL1 influences cellular oxLDL uptake. Herein we show that UCHL1 deletion significantly inhibits lipid accumulation and foam cell formation. Subsequently, we found that UCHL1 inhibitor or siRNA downregulates the expression of CD36 protein whereas SR-A, ABCA1, ABCG1, Lox-1, and SR-B1 have no significant change. Furthermore, the treatment of UCHL1 inhibition increases the abundance of K48-polyubiquitin on CD36 and the suppression of lipid uptake induced by UCHL1 deficiency is attenuated by blocking CD36 activation. Our study concluded that UCHL1 deletion decreases foam cell formation by promoting the degradation of CD36 protein, indicating UCHL1 may be a potential target for atherosclerosis treatment.

Direct Interaction of Daxx and Androgen Receptor Is Required for Their Regulatory Activity in Cholesterol Biosynthesis

Introduction: Homeostasis of cholesterol is crucial for cellular function, and dysregulated cholesterol biosynthesis is a metabolic event that can lead to hepatic and cardiovascular abnormalities. Objective: The aim of this study was to investigate the effects and mechanisms of domain-associated protein (Daxx) and androgen receptor (AR) on intracellular cholesterol synthesis. Methods: HepG2 cells were transfected with pCDNA3.1(+)/Daxx plasmid or treated with testosterone propionate to observe the effects of Daxx and AR on intracellular cholesterol levels. Co-immunoprecipitation experiments were performed to identify the interaction between Daxx and AR and to explore the regulatory effects of this interaction on cholesterol synthesis. Results: Our experiments showed that AR promoted cholesterol synthesis and accumulation by activating sterol-regulatory element-binding protein isoform 2. AR-induced cholesterol synthesis was inhibited by Daxx; however, the expression of AR was not affected. Further studies demonstrated the existence of direct binding between Daxx and AR and this interaction was required to suppress AR activity. Conclusions: The Daxx-mediated antagonism of AR depicts a more complete picture as to how Daxx regulates intracellular cholesterol level and provides a new target for treatment of atherosclerosis.