Department of Coronary Heart Disease, First Affiliated Hospital of Xinjiang Medical University.
Xinjiang Medical University.
Int Heart J. 2023;64(5):918-927. doi: 10.1536/ihj.23-089.
Circular RNAs (circRNAs) are known to play a crucial role in the progression of atherosclerosis (AS). In this study, we aim to explore the function of oxidized low-density lipoprotein (ox-LDL)-induced macrophage-derived exosomal circ_100696 in AS.THP-1 macrophages were induced by ox-LDL to mimic AS cell model. A quantitative real-time polymerase chain reaction (qRT-PCR) assay was applied to determine the expression of circ_100696, microRNA-503-5p (miR-503-5p), and pregnancy-associated plasma protein A (PAPPA). The morphology and size distribution of exosomes were examined by transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA). Western blot assay was performed for protein levels. Cell proliferation was assessed using 5-ethynyl-2'-deoxyuridine (EdU) assay. Flow cytometry analysis was performed to analyze the cell cycle. Wound-healing assay and transwell assay were done to examine cell migration. RNA pull-down assay, dual-luciferase reporter assay, and RNA immunoprecipitation (RIP) assay were employed to analyze the relationship among circ_100696, miR-503-5p, and PAPPA.Circ_100696 level was increased in ox-LDL-induced THP-1 macrophages and ox-LDL-treated THP-1 macrophage-derived exosomes (OM-Exo). OM-Exo promoted the proliferation, cell cycle, and migration of vascular smooth muscle cells (VSMCs). Circ_100696 was upregulated in VSMCs cocultured with OM-Exo. Circ_100696 knockdown reversed the effects of OM-Exo on VSMC proliferation and migration. Circ_100696 was demonstrated to function as the sponge for miR-503-5p, and miR-503-5p directly targeted PAPPA. Circ_100696 overexpression facilitated VSMC proliferation and migration, with miR-503-5p upregulation or PAPPA silencing reversing these effects. Moreover, circ_100696 overexpression promoted PAPPA expression by targeting miR-503-5p.OM-Exo promoted VSMC growth and migration by regulating the circ_100696/miR-503-5p/PAPPA axis, thereby promoting AS progression.
环状 RNA（circRNA）被认为在动脉粥样硬化（AS）的进展中起着至关重要的作用。在这项研究中，我们旨在探讨氧化型低密度脂蛋白（ox-LDL）诱导的巨噬细胞衍生外泌体 circ_100696 在 AS 中的功能。通过 ox-LDL 诱导 THP-1 巨噬细胞来模拟 AS 细胞模型。应用实时定量聚合酶链反应（qRT-PCR）测定 circ_100696、微小 RNA-503-5p（miR-503-5p）和妊娠相关血浆蛋白 A（PAPPA）的表达。透射电子显微镜（TEM）和纳米颗粒跟踪分析（NTA）检查外泌体的形态和大小分布。通过 Western blot 测定蛋白质水平。使用 5-乙炔基-2'-脱氧尿苷（EdU）测定法评估细胞增殖。流式细胞术分析用于分析细胞周期。划痕愈合试验和 Transwell 试验用于检测细胞迁移。RNA 下拉测定、双荧光素酶报告测定和 RNA 免疫沉淀（RIP）测定用于分析 circ_100696、miR-503-5p 和 PAPPA 之间的关系。在 ox-LDL 诱导的 THP-1 巨噬细胞和 ox-LDL 处理的 THP-1 巨噬细胞衍生外泌体（OM-Exo）中，circ_100696 水平增加。OM-Exo 促进血管平滑肌细胞（VSMCs）的增殖、细胞周期和迁移。在与 OM-Exo 共培养的 VSMCs 中，circ_100696 上调。circ_100696 敲低逆转了 OM-Exo 对 VSMC 增殖和迁移的影响。Circ_100696 被证明是 miR-503-5p 的海绵，miR-503-5p 直接靶向 PAPPA。Circ_100696 过表达促进 VSMC 增殖和迁移，上调 miR-503-5p 或沉默 PAPPA 可逆转这些作用。此外，circ_100696 过表达通过靶向 miR-503-5p 促进 PAPPA 表达。OM-Exo 通过调节 circ_100696/miR-503-5p/PAPPA 轴促进 VSMC 生长和迁移，从而促进 AS 进展。
