KLF15基因对心肌纤维化的抑制作用

Krüppel-like factor 15 inhibits myocardial fibrosis in rat cardiac fibroblast hypertrophy in vitro

目的探讨心肌成纤维细胞Krüppel样因子15(krüppel-like factor 15,KLF15)在心肌间质纤维化及转归中的作用和分子机制。方法体外培养大鼠心肌成纤维细胞,建立促心肌成纤维细胞肥大模型,构建干涉和过表达KLF15腺病毒载体并转染,分别进行腺病毒组、空病毒组、对照组、阴性干涉组及干涉组细胞玻片染色观察,Ⅰ、Ⅲ型胶原纤维含量及KLF15、TGF-β(transforming growth factor-β)、CTGF(connective tissue growth factor)、MRTF-A(myocardin-related transcription factor A)细胞因子蛋白表达水平检测。结果在该细胞模型实验中,腺病毒组KLF15表达水平明显高于其余各组(P<0.05),相应的TGF-β、CTGF、MRTF-A表达水平及Ⅰ、Ⅲ型胶原纤维含量却最低(P<0.05),心肌细胞肥大、纤维化表现显著减轻,而干涉组上述各检测值变化恰与之相反(P<0.05),有更重的心肌细胞肥大、纤维化表现。结论 KLF15可通过反馈调节TGF-β,抑制CTGF及MRTF-A的作用,减轻心肌间质纤维化及心肌成纤维细胞表型转变,从而改善心功能。

Objective Krüppel-like factor 15（KLF15） is a transcription factor and its expression is lost in the cardiac remodeling process associated with pathological cardiac hypertrophy prior to heart failure progression.We explored the role of KLF15 in the myocardial fibrosis process.Methods Cardiac fibroblasts of rats were cultured in vitro and then we developed a cell hypertrophy model.The cardiac fibroblasts were treated with KLF15 siRNA or KLF15 expression adenoviruses.The morphology of cell climbing slice was observed.Collagens type Ⅰ and type Ⅲ were detected by enzyme-linked immunosorbent assay（ELISA）.protein expression levels of KLF15,transforming growth factor-β（TGF-β）,connective tissue growth factor（CTGF） and myocardin-related transcription factor A（MRTF-A） were determined by Western blotting.Results The cardiac fibroblasts treated with KLF15 expression adenoviruses showed significant overexpression of KLF15（P 0.05） and reduced expression of collagen type Ⅰ,collagen type Ⅲ,TGF-β,CTGF and MRTF-A（P 0.05）,and displayed relieved hypertrophy and fibrosis.However,the cardiac fibroblasts treated with KLF15 siRNA had contrary results（P 0.05）.Conclusion KLF15 inhibits cardiac interstitial fibrosis and cardiac fibroblast phenotypic transformation by feedback controlling of TGF-β and expression inhibition of CTGF and MRTF-A.The cardiac function is markedly ameliorated.