TGF-β1通过抑制HIF-1α减少风湿性心脏病心肌细胞胶原合成

Transforming Growth Factor beta 1 Inhibits the Collagen Synthesis of Rheumatic Cardiomyocytes by Reducing Hypoxia Inducible Factor-1 alpha

目的:探讨缺氧诱导因子-1α(HIF-1α)在转化生长因子β1(TGF-β1)促风湿性心脏病心肌细胞胶原合成中的作用。方法:以体外培养风湿性心脏病(风心病)患者经瓣膜置换术后留取组织分离而来的心肌细胞为研究对象,依据加入TGF-β1的浓度将前期实验分为四组:0,5,10及20(μg/L),观察TGF-β1对风湿性心脏病心肌细胞胶原合成及HIF-1α表达的影响;而后实验选取10μg/L TGF-β1为干预浓度,将Scrambled si RNA或HIF-1αsi RNA转染入细胞内。48小时后,分别收集各组细胞,采用RT-PCR检测I型胶原的m RNA水平,Western Blot技术测定细胞内I型胶原和HIF-1α的蛋白表达水平。结果:与0、5及10μg/L浓度TGF-β1组相比,5、10及20μg/L浓度的TGF-β1分别显著地增加了风心病心肌细胞I型胶原及HIF-1α的表达。另外,HIF-1αsi RNA则明显减少了TGF-β1诱导的心肌细胞I型胶原生成。结论:HIF-1α介导了TGF-β1对风湿性心脏病心肌细胞I型胶原合成的促进作用。

Objective： To elucidate the effect of hypoxia inducible factor-1 alpha（HIF-1α）on generation of Type I collagen in rheumatic cardiomyocytes induced by transforming growth factor beta 1（TGF-β1）. Methods： Human rheumatic cardiomyocytes were cultured in vitro, the pre-experiment was divided into 4 groups as follows： 0, 5, 10 and 20（μg/L）, according to the concentration of TGF-β1. Then, we chose 10 μg/L TGF-β1, and transfected rheumatic cardiomyocytes with non-specific si RNA or HIF-1α si RNA. 48 hours later, the cells were collected. Type I collagen m RNA was detected by RT-PCR, the expression of Type I collagen and HIF-1α was determined by Western Blot. Results： Compared with 0, 5, 10 μg/L TGF-β1 groups, 5, 10, 20 μg/L TGF-β1 significantly increased the synthesis of Type I collagen and expression of HIF-1α. In addition, HIF-1α si RNA markedly decreased generation of Type I collagen induced by TGF-β1. Conclusion： HIF-1α participates in TGF-β1 induced synthesis of Type I collagen in rheumatic cardiomyocytes.