Department of Cardiology, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China.
Cell Biol Int. 2023 Jul;47(7):1267-1280. doi: 10.1002/cbin.12018. Epub 2023 Apr 5.
Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor has been demonstrated to exert a great cardioprotection in cardiometabolic impairments, including atherosclerosis. However, its underlying mechanism remains not fully understood. This study focuses on uncovering the actions of PCSK9 inhibitor on the connection between atherosclerosis and vascular smooth muscle cell (VSMC) behaviors. qRT-PCR was utilized to detect the expression of SNHG16. Proliferation and migration of VSMC were characterized by Cell Counting Kit-8 and wound healing assays. The intracellular lipids and foam cell formation were assessed by Oil Red O staining, fluorescence image, and cholesterol quantification kit. Atherosclerosis in vivo was evaluated by imaging the atherosclerotic lesions, hematoxylin-eosin staining, Oil Red O staining and Masson staining. The interaction between SNHG16 with EZH2 and histone H3 lysine 27 trimethylation (H3K27me3) were investigated by fluorescence in situ hybridization, RNA immunoprecipitation, and chromatin immunoprecipitation assays. A ApoE mice model was used to validate the role of PCSK9 inhibitor and SNHG16 for atherosclerosis. The protective regulation of PCSK9 inhibitor was observed both in high-fat diet (HFD)-fed mice and oxidized low-density lipoprotein (ox-LDL)-treated VSMC, as manifested in the decreased the atherosclerotic lesions in vivo, as well as the weakened cell proliferation, migration, and formation of foam cells in vitro. SNHG16 was identified to be a downstream effector of PCSK9 inhibitor-mediated biological functions, of which knockdown also significantly ox-LDL-treated VSMC proliferation, migration, and foam cell formation abilities. SNHG16 epigenetically suppressed TRAF5 via recruiting EZH2. Silencing of TRAF5 abolished the protective effects of SNHG16 knockdown on the pathogenesis of atherosclerosis. Collectively, PCSK9 inhibitor attenuated atherosclerosis by regulating SNHG16/EZH2/TRAF5 axis to impair the proliferation, migration, and foam cell formation of VSMC.
前蛋白转化酶枯草溶菌素 9（PCSK9）抑制剂已被证明在代谢性心血管疾病损伤中具有很大的心脏保护作用，包括动脉粥样硬化。然而，其潜在机制仍不完全清楚。本研究旨在揭示 PCSK9 抑制剂对动脉粥样硬化与血管平滑肌细胞（VSMC）行为之间联系的作用。qRT-PCR 用于检测 SNHG16 的表达。通过细胞计数试剂盒-8 和划痕愈合实验来表征 VSMC 的增殖和迁移。用油红 O 染色、荧光图像和胆固醇定量试剂盒评估细胞内脂质和泡沫细胞形成。通过成像动脉粥样硬化病变、苏木精-伊红染色、油红 O 染色和 Masson 染色评估体内动脉粥样硬化。通过荧光原位杂交、RNA 免疫沉淀和染色质免疫沉淀实验研究 SNHG16 与 EZH2 和组蛋白 H3 赖氨酸 27 三甲基化（H3K27me3）的相互作用。使用 ApoE 小鼠模型验证 PCSK9 抑制剂和 SNHG16 对动脉粥样硬化的作用。在高脂饮食（HFD）喂养的小鼠和氧化型低密度脂蛋白（ox-LDL）处理的 VSMC 中观察到 PCSK9 抑制剂的保护调节作用，表现为体内动脉粥样硬化病变减少，以及体外细胞增殖、迁移和泡沫细胞形成减弱。SNHG16 被鉴定为 PCSK9 抑制剂介导的生物学功能的下游效应物，其敲低也显著减弱 ox-LDL 处理的 VSMC 增殖、迁移和泡沫细胞形成能力。SNHG16 通过募集 EZH2 对 TRAF5 进行表观遗传抑制。沉默 TRAF5 消除了 SNHG16 敲低对动脉粥样硬化发病机制的保护作用。总之，PCSK9 抑制剂通过调节 SNHG16/EZH2/TRAF5 轴来抑制 VSMC 的增殖、迁移和泡沫细胞形成，从而减轻动脉粥样硬化。
