中文摘要：

目的研究高糖诱导的心肌间质纤维化（心肌成纤维细胞表型转化以及胶原分泌）过程中活化素受体样激酶7（ALK7）的作用。方法体外高糖培养大鼠心肌成纤维细胞，免疫荧光法观察成纤维细胞表型转化，realtime—PCR法检测心肌成纤维细胞ALK7和I型前胶原mRNA的表达水平，ELISA法检测心肌成纤维细胞分泌I型胶原水平，Western—blotting法测定心肌成纤维细胞ALK7蛋白的表达水平；siRNA抑制ALK7表达，再次观察高糖对心肌成纤维细胞表型转化及上述各因子表达的影响。结果高糖刺激心肌成纤维细胞转化为肌成纤维细胞；高糖促进I型胶原mRNA和蛋白的表达（P〈0．05）；高糖促进成纤维细胞ALK7mRNA和蛋白的表达（P〈0．05）；ALK7siRNA抑制ALK7的表达后，高糖促进心肌成纤维细胞转化及合成I型胶原的作用下降（P〈0．05）。结论ALK7参与了高糖诱导的心肌成纤维细胞表型转化及合成I型胶原的代谢过程。

英文摘要：

Objective To investigate the role of ALK7 in the process of myocardial interstitial fibrosis （ transformation of cardiac fibroblasts and the production of collagen type I by cardiac fibroblasts） induced by high glucose. Methods Neonatal rat cardiac fibroblasts were cultured in vitro with different concentrations of glucose. Fibroblast phenotype transformation was observed by immumofluorescence method. The mRNA expressions of collagen type I and ALK7 were measured by real time-PCR ; the protein level of collagen type I was determined by enzyme-linked immunosorbent assay ; the protein level of ALK7 was measured by Western-blotting analysis. Thereafter, we investigated the theraputic effects of ALK7 siRNA on the above changes induced by high glucose. Results The transformation of cardiac fibro- blasts to myofibroblast increased by high glucose; Both mRNA mad protein expressions of collagen type I increased after high glucose stimulation （ P 〈 0.05 ） ; The mRNA and protein expressions of ALK7 increased by high glucose （ P 〈 0.05 ） ; The increased mRNA and protein levels of collagen type I and the transformation of cardiac fibroblasts inducedby high glucose were reversed by treatment with ALK7 siRNA （P 〈 0.05 ）. Conclusion ALK7 is involved in the transformation of cardiac fibroblasts to myofibroblast and the production of collagen type I by cardiac fibroblasts induced by high glucose.