Department of Geriatrics, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, P.R. China.
Department of Anesthesiology, The Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, P.R. China.
Int J Mol Med. 2019 Mar;43(3):1311-1320. doi: 10.3892/ijmm.2019.4074. Epub 2019 Jan 23.
Vascular senescence is considered to be an independent risk factor for cardiovascular diseases. The present study aimed to investigate the effects of rapamycin on miR‑30a and its relationship with autophagy and senescence in vascular smooth muscle cells (VSMCs). Young and aging VSMCs were treated with rapamycin or transfected with miR‑30a mimics. Measurement of cellular senescence was conducted using senescence‑associated (SA)‑β‑Galactosidase (gal) staining. Dual luciferase reporter assay was used to confirm binding for miR‑30a and Beclin1. The expression levels of miR‑30a and Beclin1 were determined with reverse transcription‑quantitative polymerase chain reaction analysis. Autophagy‑related protein levels were determined using immunofluorescence or western blot assays. The results demonstrated that rapamycin treatment significantly decreased miR‑30a expression and increased Beclin1 expression in both young and aging cells, as well as promoted autophagy in VSMCs. In addition, rapamycin inhibited senescence in VSMCs and could also alleviate the aging VSMC cycle arrest. Dual luciferase reporter assay confirmed that miR‑30a could directly bind the 3'untranslated region of Beclin1 and inhibit its expression. Furthermore, miR‑30a inhibited autophagy and promoted senescence of VSMCs. In conclusion, the present results indicated that rapamycin could inhibit the senescence of VSMCs by downregulating miR‑30a, which resulted in upregulation of Beclin1 and activation of autophagy. The current study is the first to demonstrate an inhibitory role of rapamycin on VSMC senescence and might provide novel insights and potential new molecular targets in senescence treatment.
血管衰老被认为是心血管疾病的独立危险因素。本研究旨在探讨雷帕霉素对 miR-30a 的影响及其与血管平滑肌细胞（VSMC）自噬和衰老的关系。用雷帕霉素或 miR-30a 模拟物转染年轻和衰老的 VSMC。通过衰老相关（SA）-β-半乳糖苷酶（gal）染色检测细胞衰老。双荧光素酶报告实验用于证实 miR-30a 和 Beclin1 的结合。采用逆转录-定量聚合酶链反应分析检测 miR-30a 和 Beclin1 的表达水平。采用免疫荧光或 western blot 检测自噬相关蛋白水平。结果表明，雷帕霉素处理可显著降低年轻和衰老细胞中 miR-30a 的表达，增加 Beclin1 的表达，并促进 VSMC 中的自噬。此外，雷帕霉素可抑制 VSMC 的衰老，缓解衰老 VSMC 的周期阻滞。双荧光素酶报告实验证实，miR-30a 可直接结合 Beclin1 的 3'UTR 并抑制其表达。此外，miR-30a 抑制 VSMC 的自噬并促进其衰老。综上所述，本研究结果表明，雷帕霉素通过下调 miR-30a 抑制 VSMC 衰老，从而上调 Beclin1 并激活自噬。本研究首次证明了雷帕霉素对 VSMC 衰老的抑制作用，为衰老治疗提供了新的见解和潜在的新分子靶点。
