Wu Yukun, Qin Xiao, Xiang Mengxiang, Deng Jiangbei
Department of peripheral vascular intervention, The Affiliated Changsha Central Hospital, Hengyang Medical School, University of South China, Changsha, People's Republic of China.
Department of Vascular Surgery, The First Affiliated Hospital of Guangxi Medical University, Nanning, People's Republic of China.
FASEB J. 2025 May 15;39(9):e70579. doi: 10.1096/fj.202403269R.
Aortic dissection (AD) is a highly alarming clinical condition of the aorta, with a significant mortality rate. Vascular smooth muscle cell (VSMC) senescence dominantly promotes AD progression. This study planned to clarify the exact functions and mechanisms of protein arginine methyltransferase 1 (PRMT1), E2F7, and Sirtuin 6 (SIRT6) in the VSMC senescence of the AD model. Angiotensin II (Ang II) and β-Aminopropionitrile (BAPN) were used to treat VSMCs or C57BL/6J mice to establish the AD in vitro or in vivo model. Protein expressions were examined by western blot, IHC, and IF staining. Histological change or cell senescence was monitored using H&E or senescence-associated-β-galactosidase (SA-β-gal) staining. Enzyme-Linked Immunosorbent Assay (ELISA) assays were utilized to evaluate senescence-associated secretory phenotype markers' levels. The binding interactions between E2F7 and SIRT6 or PRMT1 and E2F7 were verified by the luciferase reporter, ChIP Co-IP, and GST-pull-down analysis. The ubiquitination levels of E2F7 were assessed using ubiquitination assays. PRMT1, E2F7, and SIRT6 protein levels were decreased in the Ang II-treated VSMCs of the AD model. Moreover, E2F7 repressed cell senescence by transcriptionally regulating SIRT6 in the AD model. PRMT1 silencing promoted cell senescence of VSMCs under Ang II. Further, PRMT1-mediated arginine methylation could maintain the protein stability of E2F7. PRMT1 restrained cell senescence of VSMCs via the E2F7/SIRT6 axis in the AD model. PRMT1 enhanced arginine methylation of E2F7, leading to the upregulation of SIRT6, thereby inhibiting the senescence of VSMCs in the AD model.
主动脉夹层（AD）是一种高度危险的主动脉临床病症，死亡率很高。血管平滑肌细胞（VSMC）衰老在很大程度上促进了AD的进展。本研究旨在阐明蛋白质精氨酸甲基转移酶1（PRMT1）、E2F7和沉默调节蛋白6（SIRT6）在AD模型VSMC衰老中的具体功能和机制。使用血管紧张素II（Ang II）和β-氨基丙腈（BAPN）处理VSMC或C57BL/6J小鼠，以建立体外或体内AD模型。通过蛋白质印迹、免疫组化和免疫荧光染色检测蛋白质表达。使用苏木精-伊红（H&E）或衰老相关β-半乳糖苷酶（SA-β-gal）染色监测组织学变化或细胞衰老。采用酶联免疫吸附测定（ELISA）评估衰老相关分泌表型标志物的水平。通过荧光素酶报告基因、染色质免疫沉淀联合免疫共沉淀（ChIP Co-IP）和谷胱甘肽S-转移酶下拉（GST-pull-down）分析验证E2F7与SIRT6或PRMT1与E2F7之间的结合相互作用。使用泛素化测定评估E2F7的泛素化水平。在AD模型中，Ang II处理的VSMC中PRMT1、E2F7和SIRT6蛋白水平降低。此外，在AD模型中，E2F7通过转录调控SIRT6抑制细胞衰老。在Ang II作用下，PRMT1沉默促进了VSMC的细胞衰老。此外，PRMT1介导的精氨酸甲基化可维持E2F7的蛋白质稳定性。在AD模型中，PRMT1通过E2F7/SIRT6轴抑制VSMC的细胞衰老。PRMT1增强了E2F7的精氨酸甲基化，导致SIRT6上调，从而抑制AD模型中VSMC的衰老。
