MicroRNA-24 aggravates atherosclerosis by inhibiting selective lipid uptake from HDL cholesterol via the post- transcriptional repression of scavenger receptor class Btype I
MicroRNA-24 aggravates atherosclerosis by inhibiting selective lipid uptake from HDL cholesterol via the post- transcriptional repression of scavenger receptor class Btype I
复制标题
MicroRNA-24 通过转录后抑制 I 型 B 类清道夫受体，抑制 HDL 胆固醇的选择性脂质摄取，从而加剧动脉粥样硬化
DOI：
10.1016/j.atherosclerosis.2018.01.045
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发表时间：
2018-03-01
期刊：
影响因子：
5.3
通讯作者：
Yi, Guang-Hui
中科院分区：
文献类型：
--
作者：
Ren, Kun;Zhu, Xiao;Yi, Guang-Hui
Background and aims: Liver scavenger receptor class B type I (SR-BI) exerts atheroprotective effects through selective lipid uptake (SLU) from high-density lipoprotein cholesterol (HDL-C). Low hepatic SRBI expression leads to high HDL-C levels in the circulation and an increased risk of atherosclerosis. Furthermore, macrophage SR-BI mediates bidirectional cholesterol flux and may protect against atherogenesis. Previous studies have revealed that miR-24 is closely related to cardiovascular disease (CVD) progression. We aimed to investigate the molecular mechanisms by which miR-24 participates in SR-BI-mediated selective HDL cholesteryl ester (HDL-CE) uptake and further atherogenesis in apoE(-/-) mice.Methods: Bioinformatic predictions and luciferase reporter assays were utilized to detect the association between miR-24 and the SR-BI 30 untranslated region (30 UTR), and RT-PCR and western blotting were used to evaluate SR-BI mRNA and protein expression, respectively. The effects of miR-24 on Dil-HDL uptake were determined by flow cytometry assay. Double-radiolabeled HDL (I-125-TC-/[H-3] CEt-HDL) was utilized to measure the effects of miR-24 on HDL and CE binding and SLU in HepG2 and PMAtreated THP-1 cells. In addition, total cholesterol (TC) levels in HepG2 cells were analyzed using enzymatic methods, and macrophage lipid content was evaluated by high-performance liquid chromatography (HPLC) assay. Small interfering RNA (siRNA) and pcDNA3.1(-)-hSR-BI plasmid transfection procedures were utilized to confirm the role of SR-BI in the effects of miR-24 on Dil-HDL uptake, SLU and cholesterol levels in both cell types. Hepatic SR-BI level in apoE(-/-) mice was measured by western blotting. Liver TC, FC and CE levels and plasma triglycerides (TG), TC and HDL-C levels were evaluated enzymatically using commercial test kits. Atherosclerotic lesion sizes were measured using Oil Red O and hematoxylin-eosin staining.Results: miR-24 directly repressed SR-BI expression by targeting its 30UTR. In addition, miR-24 decreased Dil-HDL uptake and SLU in HepG2 and THP-1 macrophages. In the presence of HDL, miR-24 decreased TC levels in HepG2 cells and TC, free cholesterol (FC) and CE levels in macrophages. Overexpression and down-regulation assays showed that SR-BI mediated the effects of miR-24 on Dil-HDL uptake, SLU and cholesterol levels. Lastly, miR-24 administration decreased hepatic SR-BI expression and promoted atheromatous plaque formation in apoE(-/-) mice, findings in line with those of our in vitro studies.Conclusions: These findings indicate that miR-24 accelerates atherogenesis by repressing SR-BI-mediated SLU from HDL-C. (c) 2018 Elsevier B.V. All rights reserved.
