芪苈强心提取物阻断Smad3信号通路抑制血管紧张素Ⅱ诱导的心脏成纤维细胞转分化

目的观察芪苈强心提取物对血管紧张素II（Angiotensin II,Ang II）诱导的心脏成纤维细胞转分化的影响,探讨芪苈强心胶囊在改善心肌重构方面的分子机制。方法采用胰酶消化法培养新生SD大鼠的心脏成纤维细胞（Cardiac fibroblasts,CFs）,传代后将CFs细胞随机分为：对照组,Ang II（10-6mol/l）组,芪苈强心提取物（0.5mg/ml）组和Ang II＋芪苈强心提取物组。以芪苈强心预处理CFs细胞1h,再以Ang II干预6h,采用免疫荧光和Western Blot等方法分别检测α-SMA,TGF-βl以及TGF-βl下游信号通路中Smad3和Smad6蛋白及磷酸化表达水平。结果与对照组相比,Ang II组CFs的α-SMA、TGF-βl蛋白表达增加。与Ang II组比较,芪苈强心提取物能减少Ang II诱导的α-SMA、TGF-βl蛋白表达,同时降低Smad3蛋白的磷酸化水平,增加Smad6蛋白的表达。结论芪苈强心提取物通过调控TGF-βl/Smads信号通路,实现抑制Ang II诱导的CFs转分化,这可能是芪苈强心改善心肌重构的重要分子机制之一。

Qiliqiangxin Extract Inhibits Angiotensin II-induced Cardiac Fbroblasts Transdifferentiation Through Blocking Smad3 Pathway

Objective To investigate the role of Qiliqiangxin extract in cardiac fibroblasts transdifferentiation induced by angiotensin II and the underlying mechanism. Methods Primary cultured cardiac fibroblasts were isolated from neonatal SD rats and digested by trypsin. Cells were randomly divided into 4 groups： control group, Ang II treated group（10-6mol/l）, Qiliqiangxin extracttreated treated group（0.5mg/ml）, and Ang II with Qiliqiangxin extract treated group. CFs were pretreated with Qiliqiangxin for 1h followed by angiotensin II processing for 6h. The protein expressions of α-SMA, TGF-βl and its downstream Smad3 and Smad6 were detected with Western blotting or immunocytofluorescence. Results Angiotensin II enhanced α-SMA and TGF-βl in cardiac fibroblasts, which was significantlydownregulated by Qiliqiangxin.Meanwhile, Qiliqiangxin also decreased the phosphorylation level of Smad3, and increased expressions of Smad6. Conclusion Qiliqiangxin extract inhibits Angiotensin II-induced cardiac fibroblasts transdifferentiation through TGF-βlmediated Smad3 pathway, which may be involved in its cardiac reverse remodeling and heart failure improvement.