MicroRNA-874-5p regulates autophagy and proliferation in pulmonary artery smooth muscle cells by targeting Sirtuin 3.
MicroRNA-874-5p regulates autophagy and proliferation in pulmonary artery smooth muscle cells by targeting Sirtuin 3.
复制标题
DOI：
10.1016/j.ejphar.2020.173485
复制
发表时间：
2020-08
影响因子：
5
通讯作者：
Lixin Zhang;Cui Ma;Xiaoying Wang;June Bai;Siyu He;Junting Zhang;W. Xin;Yiying Li;Yuan Jiang-Y
中科院分区：
文献类型：
--
作者：
Lixin Zhang;Cui Ma;Xiaoying Wang;June Bai;Siyu He;Junting Zhang;W. Xin;Yiying Li;Yuan Jiang-Y
自噬是缺氧性肺动脉高压（PH）下病理性血管重构的主要原因。Sirtuin 3（Sirt 3）参与了细胞自噬的调控，但其在缺氧性PH中的作用，特别是其分子机制尚不清楚。在本研究中，蛋白质印迹，免疫组化，免疫荧光，溴脱氧尿苷掺入和细胞周期分析进行，以阐明缺氧诱导的自噬和细胞增殖的潜在机制与Sirt 3。我们观察到，在缺氧条件下，Sirt 3的表达降低，Sirt 3的过表达显著抑制缺氧对自噬的影响。接下来，我们研究了microRNA在缺氧条件下与Sirt 3相关的自噬中的机制作用，使用荧光素酶报告基因，微量热泳和RNA免疫沉淀试验，结果证实Sirt 3是miR-874- 5 p的直接靶点。此外，miR-874- 5 p在缺氧后上调，而miR-874- 5 p耗竭反过来抑制自噬，从而抑制异常平滑肌细胞增殖。这些发现提供了关于与PH相关的自噬和增殖变化的miR-874- 5 p/Sirt 3级联的贡献的见解。
Autophagy is a major cause of pathological vascular remodeling under hypoxic pulmonary hypertension (PH). Sirtuin 3 (Sirt 3) has recently been reported to be involved in the regulation of autophagy, however, its role as an autophagy regulator during hypoxic PH, particularly the molecular mechanism, remains poorly understood. In the present study, Western blot, immunohistochemistry, immunofluorescence, bromodeoxyuridine incorporation and cell cycle analyses were performed to elucidate the underlying mechanism of hypoxia-induced autophagy and cell proliferation with respect to Sirt 3. We observed that the Sirt 3 expression was decreased under hypoxia and that Sirt 3 overexpression significantly inhibited the effects of hypoxia on autophagy. Next, we investigated the mechanistic role of microRNAs in Sirt 3-associated autophagy under hypoxic conditions, with luciferase reporter, microscale thermophoresis and RNA immunoprecipitation assays, results confirming that Sirt 3 is a direct target of miR-874-5p. Furthermore, miR-874-5p was upregulated following hypoxia, and miR-874-5p depletion in turn inhibited autophagy and consequently suppressed abnormal smooth muscle cell proliferation. These findings provide insight into the contribution of the miR-874-5p/Sirt 3 cascade with regard to changes in autophagy and proliferation associated with PH.