Negative feedback regulation between microRNA let-7g and LOX-1 mediated hypoxia-induced PASMCs proliferation
Negative feedback regulation between microRNA let-7g and LOX-1 mediated hypoxia-induced PASMCs proliferation
复制标题
microRNA let-7g 和 LOX-1 介导缺氧诱导 PASMC 增殖的负反馈调节
DOI：
10.1016/j.bbrc.2017.01.073
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发表时间：
--
影响因子：
3.1
通讯作者：
Zheng Zhang
中科院分区：
文献类型：
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作者：
Wei-Fang Zhang;Tian-Tian Zhu;You-Wen Xiong;Ai-Zhen Xiong;Xiao-Yue Ge;Chang-Ping Hu;Zheng Zhang
背景肺动脉高压（pulmonary hypertension，PH）是一种以肺动脉平滑肌细胞（pulmonary artery smooth muscle cells，PASMCs）增殖增强和凋亡抑制为特征的增殖性疾病。我们最近的研究表明let-7 g通过抑制c-myc-Bmi-1-p16信号通路抑制缺氧诱导的PASMCs增殖。然而，let-7 g的上游尚未完全确定。已有研究表明，let-7 g的靶点LOX-1也可调控人主动脉内皮细胞let-7 g的表达。本研究旨在探讨microRNAlet-7 g与LOX-1之间是否存在负反馈调节机制，以探讨其在低氧诱导PASMCs增殖中的作用。方法SD大鼠低氧（10%O2，3周）诱导肺动脉高压，HE染色观察肺动脉重构。分别用原位杂交和免疫组织化学方法检测let-7 g和LOX-1的表达和分布。用MTS、EDU和流式细胞术检测PASMCs增殖情况。采用实时荧光定量PCR和Western blotting检测let-7 g、LOX-1、calpain-1、calpain-2、calpain-4和OCT-1的表达。let-7 g模拟物可抑制低氧诱导的PASMCs增殖和LOX-1表达上调。LOX-1阻断逆转缺氧诱导的let-7 g表达下调。钙蛋白酶、蛋白激酶C和OCT-1参与let-7 g和LOX-1之间的负反馈调节。结论let-7 g和LOX-1之间的负反馈调节介导了低氧诱导的PASMCs增殖。
BackgroundPulmonary hypertension (PH) is a proliferative disorder associated with enhanced proliferation and suppressed apoptosis of pulmonary artery smooth muscle cells (PASMCs). Our lately study demonstrated that let-7g inhibited hypoxia-induced proliferation of PASMCs via repressing c-myc-Bmi-1-p16 signaling pathway. However, the upstream of let-7g has not yet been fully defined. Previous studies have shown that LOX-1, a target of let-7g, could also regulate the expression of let-7g in human aortic endothelial cells. In this present study, we aimed to investigate whether there is a negative feedback regulation between microRNA let-7g and LOX-1 in hypoxia-induced proliferation of PASMCs.MethodsSD Rats were exposed to hypoxia (10% O2, 3 weeks) to induce PH. HE staining was used to evaluate pulmonary artery remodeling. in situ hybridization and immunohistochemistry were performed to assess the expression and distribution of let-7g and LOX-1, respectively. MTS, EDU and flow cytometry were performed to evaluate PASMCs proliferation. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were conducted to assess the expression of let-7g, LOX-1, calpain-1,-2,-4, and OCT-1.ResultsThe expression of let-7g was significantly down-regulated in pulmonary arteries of hypoxia-induced PH rats accompanied by pulmonary vascular remodeling, whereas let-7g mimic inhibited hypoxia-induced proliferation of PASMCs and up-regulation of LOX-1 expression. LOX-1 blocking reversed hypoxia-induced down-regulation of let-7g expression. Calpains, protein kinase C and OCT-1 were involved in negative feedback regulation between let-7g and LOX-1.ConclusionNegative feedback regulation between let-7g and LOX-1 mediated hypoxia-induced proliferation of in PASMCs.