Department of Cardiology, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, China.
Department of Endocrinology and Metabolism, Guangdong Provincial Key Laboratory of Diabetology, Guangzhou Key Laboratory of Mechanistic and Translational Obesity Research, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510630, China.
Mol Cell Biochem. 2024 Nov;479(11):3021-3036. doi: 10.1007/s11010-023-04902-0. Epub 2023 Dec 25.
Phenotypic change of vascular smooth muscle cells (VSMCs) is the main contributor of vascular pathological remodeling in atherosclerosis. The endoplasmic reticulum (ER) is critical for maintaining VSMC function through elimination of misfolded proteins that impair VSMC cellular function. ER-associated degradation (ERAD) is an ER-mediated process that controls protein quality by clearing misfolded proteins. One of the critical regulators of ERAD is HRD1, which also plays a vital role in lipid metabolism. However, the function of HRD1 in VSMCs of atherosclerotic vessels remains poorly understood. The level of HRD1 expression was analyzed in aortic tissues of mice fed with a high-fat diet (HFD). The H&E and EVG (VERHOEFF'S VAN GIESON) staining were used to demonstrate pathological vascular changes. IF (immunofluorescence) and WB (western blot) were used to explore the signaling pathways in vivo and in vitro. The wound closure and transwell assays were also used to test the migration rate of VSMCs. CRISPR gene editing and transcriptomic analysis were applied in vitro to explore the cellular mechanism. Our data showed significant reduction of HRD1 in aortic tissues of mice under HFD feeding. VSMC phenotypic change and HRD1 downregulation were detected by cholesterol supplement. Transcriptomic and further analysis of HRD1-KO VSMCs showed that HRD1 deficiency induced the expression of genes related to ER stress response, proliferation and migration, but reduced the contractile-related genes in VSMCs. HRD1 deficiency also exacerbated the proliferation, migration and ROS production of VSMCs induced by cholesterol, which promoted the VSMC dedifferentiation. Our results showed that HRD1 played an essential role in the contractile homeostasis of VSMCs by negatively regulating ER stress response. Thus, HRD1 in VSMCs could serve as a potential therapeutic target in metabolic disorder-induced vascular remodeling.
血管平滑肌细胞（VSMCs）的表型改变是动脉粥样硬化中血管病理性重塑的主要原因。内质网（ER）对于通过消除损害 VSMC 细胞功能的错误折叠蛋白来维持 VSMC 功能至关重要。ER 相关降解（ERAD）是一种 ER 介导的过程，通过清除错误折叠的蛋白质来控制蛋白质质量。HRD1 是 ERAD 的关键调节因子之一，它在脂质代谢中也起着至关重要的作用。然而，HRD1 在动脉粥样硬化血管中的 VSMCs 中的功能仍知之甚少。分析了高脂饮食喂养的小鼠主动脉组织中的 HRD1 表达水平。H&E 和 EVG（VERHOEFF'S VAN GIESON）染色用于显示病理性血管变化。IF（免疫荧光）和 WB（western blot）用于体内和体外探索信号通路。划痕封闭和 Transwell 测定也用于测试 VSMCs 的迁移率。CRISPR 基因编辑和转录组分析用于体外探索细胞机制。我们的数据表明，高脂饮食喂养的小鼠主动脉组织中 HRD1 显著减少。通过胆固醇补充检测到 VSMC 表型改变和 HRD1 下调。转录组和进一步的 HRD1-KO VSMCs 分析表明，HRD1 缺乏诱导与 ER 应激反应、增殖和迁移相关的基因表达，但降低了 VSMCs 中与收缩相关的基因。HRD1 缺乏还加剧了胆固醇诱导的 VSMCs 的增殖、迁移和 ROS 产生，从而促进了 VSMC 去分化。我们的结果表明，HRD1 通过负向调节 ER 应激反应在 VSMCs 的收缩平衡中发挥重要作用。因此，VSMCs 中的 HRD1 可以作为代谢紊乱诱导的血管重塑的潜在治疗靶点。
