整合素连接激酶介导的高糖诱导肾小管上皮细胞纤连蛋白的表达

目的 观察在高糖刺激下纤连蛋白（FN）与整合素连接激酶(ILK) 在肾小管上皮细胞的表达情况，探讨糖尿病肾病小管间质纤维化的发病机制。 方法 以人肾小管上皮细胞株（HKC）细胞和链脲佐菌素（STZ）诱导的CD-1小鼠糖尿病动物模型为研究对象，采用Western印迹的方法检测细胞或肾组织ILK和FN蛋白的表达。通过基因转染的方法，将含无激酶活力的人ILK基因表达质粒pCMV-kdILK转染HKC细胞，观察抑制ILK活力对高糖诱导的HKC合成FN的影响。 结果 STZ注射后4周，CD-1小鼠血糖水平显著高于对照组[(20.3±2.7) mmol/L比 （6.1±1.4） mmol/L，P < 0.01]，同时，肾组织ILK和FN的表达量亦显著高于对照组，且ILK与FN表达量呈正相关(P < 0.01)。细胞培养实验证实，高糖能够刺激HKC上调ILK和FN蛋白的表达，并且呈时间和剂量依赖性。HKC细胞转染pCMV-kdILK质粒以抑制ILK的活力，能够显著地拮抗高糖刺激HKC表达FN的作用。 结论 高糖通过上调ILK蛋白增加肾小管表达并合成FN，抑制ILK能够拮抗高糖刺激HKC合成FN的作用。

High-glucose up-regulates the expression of fibronectin mediated by integrin-linked kinase in renal tubular epithelial cells

Objective To investigate the relationship between high-glucose-induced fibronectin(FN) expression and up-regulation of integrin-linked kinase(ILK) in human kidney tubular epithelial cells(HKC) and kidney of CD-1 mice. Methods Cultured human kidney tubular epithelial cells and streptozotocin (STZ)-induced diabetic model of CD-1 mice were enrolled in this study. Western blot was used to detect the expression of FN and ILK. The kinase dead ILK plasmid (pCMV-kdILK) were transferred to HKC. Results Four weeks after injection of STZ, CD-1 mice had higher blood glucose level as compared to the control [(20.3±2.7) mmol/L vs (6.1±1.4) mmol/L, P<0.01]. Meanwhile, expression of FN and ILK was significantly increased in diabetic mice as compared to the control(P<0.01). There was positive correlation between the expression of FN and ILK(r=0.899, P<0.01). High-glucose could up-regulate FN and ILK expression in cultured HKC in a time- and dose-dependent manner. Blockage of ILK activation by pCMV-kdILK abrogated high-glucose-incuced FN expression in HKC. Conclusions High-glucose can induce FN expression through up-regulating ILK expression. Blockage of ILK activation abrogates this effect.