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Objective: The purpose of this study was to explore the role of long noncoding RNA (lncRNA) prostate cancer antigen 3 (PCA3) in atherosclerosis and the underlying mechanism., Methods: The Gene Expression Omnibus (GEO) datasets were used to divide differentially expressed lncRNAs, microRNAs (miRNAs), and mRNAs. The expression of PCA3, miR-140-5p, RFX7 and ABCA1 were determined by qPCR or Western blot in ox-LDL-treated macrophages. Macrophage lipid accumulation s was evaluated using the Oil Red O staining and high-performance liquid chromatography. Target relationships among PCA3, miR-140-5p, RFX7, and ABCA1 promoter area were validated via dual-luciferase reporter gene assay or chromatin immunoprecipitation assay. The apoE -/- mouse model in vivo was designed to evaluate the effect of PCA3 on the reverse cholesterol transport (RCT) and atherosclerosis., Results: PCA3 was down-regulated in foam cells, whereas miR-140-5p was highly expressed. Overexpression of PCA3 promoted ABCA1-mediated cholesterol efflux and reduced lipid accumulation in macrophages. Besides, RFX7 bound to the ABCA1 promoter and increased ABCA1 expression. Targeted relationships and interactions on the expression between miR-140-5p and PCA3 or RFX7 were elucidated. PCA3 up-regulated ABCA1 expression by binding to miR-140-5p to up-regulate RFX7 and ABCA1 expression in macrophages. PCA3 promoted RCT and impeded the progression of atherosclerosis by sponging miR-140-5p in apoE -/- mice. Meanwhile, miR-140-5p also inhibit ABCA1 expression via downregulation of RFX7 to impede RCT and aggravate atherosclerosis., Conclusions: lncRNA PCA3 promotes ABCA1-mediated cholesterol efflux to inhibit atherosclerosis through sponging miR-140-5p and up-regulating RFX7., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Objective: Our previous study showed that Coiled-Coil Domain Containing 80 (CCDC80) accelerates the development of atherosclerosis by decreasing lipoprotein lipase (LPL) expression and activity in apoE knockout mice. However, the regulatory mechanism for CCDC80 expression is unclear. This study was designed to evaluate whether noncoding RNAs involved the regulation of CCDC80 expression in vascular smooth muscle cells., Methods and Results: Bioinformatics prediction and luciferase reporter gene results showed that miR-141-3p/200a-3p bound to the 3'UTR of CCDC80. Furthermore, miR-141-3p/200a-3p mimics decreased the expression of CCDC80 but increased LPL expression. Opposite results were observed with miR-141-3p/200a-3p inhibitors. We also found that lncRNA metastasis-associated lung adenocarcinoma transcript-1 (MALAT1) interacted with the sequences of miR-141-3p/200a-3p and decreased their expression. RT-qPCR and western blotting results showed that MALAT1 overexpression increased CCDC80 expression and decreased LPL expression, while MALAT1 knockdown displayed an opposite phenotype. The effects of both MALAT1 overexpression and knockdown were blocked by miR-141-3p/200a-3p mimics or inhibitors., Conclusions: Thus, we demonstrated that lncRNA MALAT1 regulates CCDC80 and LPL expression through miR-141-3p/200a-3p.

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., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective: Previous studies suggest that IL-8 has an important role in the regulation of cholesterol efflux, but whether miRNAs are involved in this process is still unknown. The purpose of this study is to explore whether IL-8 promotes cholesterol accumulation by enhancing miR-183 expression in macrophages and its underlying mechanism., Methods and Results: Treatment of THP-1 macrophage-derived foam cells with IL-8 decreased ABCA1 expression and cholesterol efflux. Using bioinformatics analyses and dual-luciferase reporter assays, we found that miR-183 was highly conserved during evolution and directly inhibited ABCA1 protein and mRNA expression by targeting ABCA1 3'UTR. MiR-183 directly regulated endogenous ABCA1 expression levels. Furthermore, IL-8 enhanced the expression of miR-183 and decrease ABCA1 expression. Cholesterol transport assays confirmed that IL-8 dramatically inhibited apolipoprotein AI-mediated ABCA1-dependent cholesterol efflux by increasing miR-183 expression. In contrast, treatment with anti-IL-8 antibody reversed these effects., Conclusion: IL-8 enhances the expression of miR-183, which then inhibits ABCA1 expression and cholesterol efflux. Our studies suggest that the IL-8-miR-183-ABCA1 axis may play an intermediary role in the development of atherosclerosis., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: Lipoprotein lipase (LPL) plays an important role in triglyceride metabolism. It is translocated across endothelial cells to reach the luminal surface of capillaries by glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 (GPIHBP1), where it hydrolyzes triglycerides in lipoproteins. MicroRNA 377 (miR-377) is highly associated with lipid levels. However, how miR-377 regulates triglyceride metabolism and whether it is involved in the development of atherosclerosis remain largely unexplored. Methods and Results: The clinical examination displayed that miR-377 expression was markedly lower in plasma from patients with hypertriglyceridemia compared with non-hypertriglyceridemic subjects. Bioinformatics analyses and a luciferase reporter assay showed that DNA methyltransferase 1 (DNMT1) was a target gene of miR-377. Moreover, miR-377 increased LPL binding to GPIHBP1 by directly targeting DNMT1 in human umbilical vein endothelial cells (HUVECs) and apolipoprotein E (ApoE)-knockout (KO) mice aorta endothelial cells (MAECs). In vivo, hematoxylin-eosin (H&E), Oil Red O and Masson's trichrome staining showed that ApoE-KO mice treated with miR-377 developed less atherosclerotic plaques, accompanied by reduced plasma triglyceride levels., Conclusions: It is concluded that miR-377 upregulates GPIHBP1 expression, increases the LPL binding to GPIHBP1, and reduces plasma triglyceride levels, likely through targeting DNMT1, inhibiting atherosclerosis in ApoE-KO mice.

Aims: Atherosclerosis is the most common cause of cardiovascular disease, such as myocardial infarction and stroke. Previous study revealed that microRNA (miR)-134 promotes lipid accumulation and proinflammatory cytokine secretion through angiopoietin-like 4 (ANGPTL4)/lipid lipoprotein (LPL) signaling in THP-1 macrophages., Methods: ApoE KO male mice on a C57BL/6 background were fed a high-fat/high-cholesterol Western diet, from 8 to 16 weeks of age. Mice were divided into four groups, and received a tail vein injection of miR-134 agomir, miR-134 antagomir, or one of the corresponding controls, respectively, once every 2 weeks after starting the Western diet. After 8 weeks we measured aortic atherosclerosis, LPL Activity, mRNA and protein levels of ANGPTL4 and LPL, LPL/ low-density lipoprotein receptor related protein 1 Complex Formation, proinflammatory cytokine secretion and lipid levels., Results: Despite this finding, the influence of miR-134 on atherosclerosis in vivo remains to be determined. Using the well-characterized mouse atherosclerosis model of apolipoprotein E knockout, we found that systemic delivery of miR-134 agomir markedly enhanced the atherosclerotic lesion size, together with a significant increase in proinflammatory cytokine secretion and peritoneal macrophages lipid contents. Moreover, overexpression of miR-134 decreased ANGPTL4 expression but increased LPL expression and activity in both aortic tissues and peritoneal macrophages, which was accompanied by increased formation of LPL/low-density lipoprotein receptor-related protein 1 complexes in peritoneal macrophages. However, an opposite effect was observed in response to miR-134 antagomir., Conclusions: These findings suggest that miR-134 accelerates atherogenesis by promoting lipid accumulation and proinflammatory cytokine secretion via the ANGPTL4/LPL pathway. Therefore, targeting miR-134 may offer a promising strategy for the prevention and treatment of atherosclerotic cardiovascular disease.

Background: Lipoprotein lipase (LPL) expressed in macrophages plays an important role in promoting the development of atherosclerosis or atherogenesis. MicroRNA-182 (miR-182) is involved in the regulation of lipid metabolism and inflammation. However, it remains unclear how miR-182 regulates LPL and atherogenesis.Methods and Results:Using bioinformatics analyses and a dual-luciferase reporter assay, we identified histone deacetylase 9 (HDAC9) as a target gene of miR-182. Moreover, miR-182 upregulated LPL expression by directly targetingHDAC9in THP-1 macrophages. Hematoxylin-eosin (H&E), Oil Red O and Masson's trichrome staining showed that apolipoprotein E (ApoE)-knockout (KO) mice treated with miR-182 exhibited more severe atherosclerotic plaques. Treatment with miR-182 increased CD68 and LPL expression in atherosclerotic lesions in ApoE-KO mice, as indicated by double immunofluorescence staining in the aortic sinus. Increased miR-182-induced increases in LPL expression in ApoE-KO mice was confirmed by real-time quantitative polymerase chain reaction and western blotting analyses. Treatment with miR-182 also increased plasma concentrations of proinflammatory cytokines and lipids in ApoE-KO mice., Conclusions: The results of the present study suggest that miR-182 upregulates LPL expression, promotes lipid accumulation in atherosclerotic lesions, and increases proinflammatory cytokine secretion, likely through targetingHDAC9, leading to an acceleration of atherogenesis in ApoE-KO mice.

Background and Aims: Several studies suggest that cardiomyocyte-enriched miR-186 is involved in cardiac injury and myocardial infarction, and also plays an important role in atherosclerotic diseases, but the underlying mechanism is unknown. Cystathionine-γ-lyase (CSE) is the predominant enzyme to produce H2S in the cardiovascular system. Here, miR-186 was identified to bind to the 3'UTR of CSE. In this study, we aimed at exploring whether miR-186 affects lipid accumulation and secretion of pro-inflammatory cytokines by targeting CSE and its underlying mechanism in human THP-1 macrophages and peripheral blood monocyte-derived macrophages (PBMDM). PBMDM just as a control group for the comparison with the THP-1 macrophages., Methods: MiR-186 target genes, CSE 3'UTR sequence and free energy were predicted and analyzed by bioinformatics analyses and dual-luciferase reporter assays. The expression of CSE mRNA and protein were measured by real-time quantitative PCR and western blot analyses. The lipid accumulation in THP-1 macrophages was detected by high performance liquid chromatography (HPLC). The effects of miR-186 on secretion of IL-6, IL-1β and TNF-α were examined by ELISA. Endogenous H2S was detected by spectrophotometry. Using small interfering RNA (siRNA) approach to decrease the expression of CSE protein and mRNA., Results: We found that miR-186 directly inhibited CSE protein and mRNA expression through targeting CSE 3'UTR by bioinformatics analyses and dual-luciferase reporter assays. HPLC assays showed that miR-186 increased the lipid accumulation in human THP-1 macrophages. We also showed that miR-186 enhanced secretion of pro-inflammatory cytokines in human THP-1 macrophages. Using siRNA approach, we found that CSE siRNA could inhibit the miR-186 inhibitor-induced decrease in the expression of LPL protein and mRNA in human THP-1 macrophages, which was accompanied a decrease in the level of H2S., Conclusions: MicroRNA-186 promotes macrophage lipid accumulation and pro-inflammatory cytokine secretion by targeting cystathionine γ-lyase in THP-1 macrophages., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

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.

This study was designed to evaluate whether CSE/H2S system, which is regulated by miR-216a, regulated ABCA1-mediated cholesterol efflux and cholesterol contents in THP-1 macrophages-derived foam cells. Our qPCR and western blotting results showed that CSE/H2S significantly up-regulated the expression of ATP-binding cassette transporter A1 (ABCA1) mRNA and protein via PI3K/AKT pathway in foam cells derived from human THP-1 macrophages. The miR-216a directly targeted 3' untranslated region of CSE. It significantly reduced CSE and ABCA1 expression, and also decreased the phosphorylation of PI3K and AKT. Additionally, cholesterol efflux decreased, and cholesterol levels increased in THP-1 macrophage-derived foam cells in response to treatment with miR-216a. Our study demonstrates that CSE/H2S system is regulated by miR-216a, and regulates ABCA1-mediated cholesterol efflux and cholesterol levels through the PI3K/AKT pathway., (Copyright © 2016 Elsevier Inc. All rights reserved.)