Department of Cardiopulmonary Rehabilitation, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
Department of Cardiovascular Medicine, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
Vascul Pharmacol. 2020 Dec;135:106782. doi: 10.1016/j.vph.2020.106782. Epub 2020 Aug 27.
Circular RNAs (circRNAs) have been identified to be critical mediators in the progression of atherosclerosis (AS). However, the exact roles and molecular mechanism of circ_0029589 in AS are far from understood.
Vascular smooth muscle cells (VSMCs) stimulated by oxidized low-density lipoprotein (ox-LDL) were served as a cellular model of AS. The expression levels of circ_0029589, microRNA (miR)-424-5p, and insulin-like growth factor 2 (IGF2) were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot analysis. Cell proliferation was determined by Cell Counting Kit-8 (CCK-8) assay and colony formation assay. Cell apoptosis, migration and invasion were examined by flow cytometry and transwell assay. The relationship between miR-424-5p and circ_0029589 or IGF2 was predicted by starbase and verified by dual-luciferase reporter assay.
Circ_0029589 and IGF2 were upregulated and miR-424-5p was downregulated in VSMCs treated with ox-LDL. Silence of circ_0029589 inhibited proliferation, migration and invasion but induced apoptosis in ox-LDL-treated VSMCs. MiR-424-5p was a target of circ_0029589 and its knockdown reversed the effects of circ_0029589 interference on proliferation, migration, invasion, and apoptosis in ox-LDL-stimulated VSMCs. IGF2 was a target of miR-424-5p and miR-424-5p overexpression suppressed proliferation, migration and invasion while promoted apoptosis in ox-LDL-treated VSMCs by downregulating IGF2. Circ_0029589 positively modulated IGF2 expression by sponging miR-424-5p.
Circ_0029589 silence might inhibit the progression of AS by regulating miR-424-5p/IGF2 axis, providing a novel mechanism for pathogenesis of AS.
环状 RNA（circRNAs）已被确定为动脉粥样硬化（AS）进展的关键介质。然而，circ_0029589 在 AS 中的确切作用和分子机制还远未被理解。
用氧化型低密度脂蛋白（ox-LDL）刺激血管平滑肌细胞（VSMCs）作为 AS 的细胞模型。通过定量实时聚合酶链反应（qRT-PCR）或 Western blot 分析测定 circ_0029589、微小 RNA（miR）-424-5p 和胰岛素样生长因子 2（IGF2）的表达水平。用细胞计数试剂盒-8（CCK-8）测定和集落形成试验测定细胞增殖。通过流式细胞术和 Transwell 试验检测细胞凋亡、迁移和侵袭。通过 starbase 预测 miR-424-5p 与 circ_0029589 或 IGF2 的关系，并通过双荧光素酶报告基因试验验证。
ox-LDL 处理的 VSMCs 中 circ_0029589 和 IGF2 上调，miR-424-5p 下调。沉默 circ_0029589 抑制 ox-LDL 处理的 VSMCs 的增殖、迁移和侵袭，但诱导凋亡。miR-424-5p 是 circ_0029589 的靶标，其敲低逆转了 circ_0029589 干扰对 ox-LDL 刺激的 VSMCs 增殖、迁移、侵袭和凋亡的影响。IGF2 是 miR-424-5p 的靶标，miR-424-5p 过表达通过下调 IGF2 抑制 ox-LDL 处理的 VSMCs 的增殖、迁移和侵袭，同时促进凋亡。Circ_0029589 通过海绵吸附 miR-424-5p 正向调节 IGF2 表达。
沉默 circ_0029589 可能通过调节 miR-424-5p/IGF2 轴抑制 AS 的进展，为 AS 的发病机制提供了新的机制。
