目的  探讨Smad7敲低后对原代心肌成纤维细胞增殖、迁移、胶原分泌和细胞表型转化的影响。   方法  原代培养10只SD大鼠乳鼠的心肌成纤维细胞，免疫组织化学染色鉴定细胞。采用慢病毒转染方法敲低心肌成纤维细胞Smad7的表达，Western blotting验证Smad7蛋白敲低效率，实时无标记细胞仪检测心肌成纤维细胞的增殖情况，细胞划痕实验检测细胞的迁移情况，Western blotting检测Ⅰ型胶原蛋白（ColⅠ）和细胞表型转化标志物α-平滑肌肌动蛋白（α-SMA）的表达情况。   结果  成功培养心肌成纤维细胞，并进行细胞鉴定。慢病毒转染的心肌成纤维细胞感染复数（MOI）值为100，转染后88.33%的细胞表达绿色荧光蛋白，慢病毒敲低组Smad7的蛋白表达明显下调（P<0.05）。慢病毒敲低Smad7后细胞增殖明显下降（P<0.01），细胞迁移率明显减少（P<0.01）。与对照组相比，慢病毒敲低组细胞 ColⅠ表达明显下降（P<0.01），α-SMA表达明显升高（P<0.01）。   结论  Smad7表达敲低后，心肌成纤维细胞的细胞功能发生明显改变，这些改变可能与Smad7下调导致心肌纤维化程度加重有关。

Objective  To investigate the effects of Smad7 knock down by lentivirus on rat cardiac fibroblasts proliferation, migration, cell differentiation and collagen secretion in vitro.    Methods  The primary cardiac fibroblasts were separated from the hearts of ten SD rats and identified by immunohistochemical method. The lentivirus transfection knocked down the expresson of Smad7 in cardiac fibroblasts, Western blotting was used to detect the efficiency of Smad7 knock down by lentivirus. The proliferation of cardiac fibroblasts was quantified by real-time unlabeled cell analyzer. Cell migration was evaluted by cell wound scratch assay. Western blotting was used to detect expression of α- smooth muscle actin (α-SMA) and collagen Ⅰ（Col Ⅰ）.  Results   Myocardial fibroblasts were successfully cultured and identified by immunocytochemical methods. The multiplicity of infection(MOI)  that lentivirus transduction of myocardial fibroblasts was 100. After lentivirus transduction, 88.33% myocardial fibroblasts expressed green fluorescent protein, showed that the lentivirus could significantly reduce the protein expression of Smad7. Smad7 deficiency decreased the proliferation and migration of cardiac fibroblasts, increased the protein expression of α-SMA and decreased collagen secretion. The results indicated that Smad7 deficiency significantly down-regulated the proliferation and migration of cardiac fibroblasts, increased α-SMA protein expression and reduced ColⅠ protein expression.  Conclusion  Smad7 deficiency can significantly change the cardiac fibroblasts function , that is related to the pathological mechanism that lead to myocardial fibrosis.