整合素连锁激酶介导转化生长因子β1上调肾小管上皮细胞表达纤连蛋白的研究

Experimental study of transforming growth factor β1 up-regulating ILK and fibronectin expression in renal tubular epithelial cells

目的研究转化生长因子β1(TGF-β1)诱导肾小管上皮细胞合成纤连蛋白(FN)与整合素连锁激酶(ILK)表达的关系。方法培养人肾小管上皮细胞(HKC),用蛋白印迹方法检测TGF-β1诱导HKC合成FN和表达ILK的作用。通过基因转染的方法,将含人野生型ILK基因的表达质粒pCMV-wtILK和无激酶活力的人ILK基因表达质粒pCMV-kdILK转染HKC细胞,观察ILK过度表达和抑制ILK活力对TGF-β1诱导的HKC合成FN的影响。结果TGF-β1能够刺激HKC合成FN,其作用呈剂量依赖性。TGF-β1刺激8 h即可上调HKC细胞ILK的表达,与TGF-β1所致的FN合成的增加相一致。转染pCMV-wtILK质粒的HKC细胞,其FN的表达呈增加趋势。转染pCMV-kdILK抑制ILK的活力能够显著拮抗TGF-β1刺激HKC表达FN的作用。结论TGF-B1刺激肾小管上皮细胞FN合成与其所致的ILK表达密切相关。抑制ILK的活力能够拮抗TGF-B1导致的FN合成。

Objective To investigate the relationship between TGF-β1-induced fibronectin （FN） expression and up-regulation of integrin-link kinase （ILK） in human kidney tubular epithelial cells （HKC）. Methods Using cell culture and Western blot, the TGF-β1-induced expression of FN and ILK was tested. The ILK expression plasmid （pCMV-wtILK） containing wild-type full-length human ILK cDNA, or kinase dead ILK cDNA were transfered to HKC. The effect of overexpression of ILK on FN expression, and the blockage of ILK activation on the action of TGF-β1 on HKC were studied. Results TGF-β1 induced FN expression of HKC in a dose-depended manner. In the timecourse study, TGF-β1 upregulated ILK expression of HKC as early as 8 hours, meanwhile it induced FN expression. Overexpression of ILK in HKC tansfered with pCMV-wtILK could induce FN expression. Blockage of ILK activation abrogated TGF-β1-induced FN expression. Conclusions A close relationship exists between TGF-β1-induced FN expression and upregulation of ILK in HKC. Blockage of ILK activation obliterates TGF-β1-induced FN expression.