整合素连接激酶在肾小管上皮细胞转分化中的作用

目的探讨整合素连接激酶（ILK）在转化生长因子β1（TGF-β1）介导的肾小管上皮细胞转分化（EMT）中的表达及作用。方法采用不同浓度的TGF-β1刺激体外培养的人肾小管上皮细胞（HKC）,观察HKC形态学改变,并应用Western blotting方法检测其ILK、α-平滑肌肌动蛋白（α-SMA）的表达,实时RT-PCR法测定ILK、α-SMA、纤维连接蛋白（FN）、E钙黏蛋白（E-cadherin）mRNA的表达。结果（1）细胞形态学改变：在TGF-β1刺激下HKC细胞由正常状态下的圆形或卵圆形变为梭形,且随着孵育时间的延长,梭形细胞比例增大。（2）Western blotting和实时RT-PCR检测结果：在TGF-β1刺激下,ILK和α-SMA的蛋白表达量显著增加;ILK、α-SMA和FN的mRNA表达量也明显升高,而E-cadherin mRNA表达量明显减少。TGF-β1呈时间和剂量依赖性刺激HKC表达ILK蛋白和mRNA。（3）相关分析：ILK蛋白表达量与α-SMA蛋白表达量呈正相关（r=0.940,P〈0.01）;ILK mRNA表达量与α-SMA mRNA、FN mRNA表达量呈正相关（r=0.926,r=0.915,P〈0.01）,与E-cadherin mRNA表达量呈负相关（r=-0.820,P〈0.01）。结论ILK参与TGF-β1诱导的肾小管EMT,并在其中发挥关键作用。

Role of integrin-linked kinase in renal tubular epithelial-to-mesenchymal transition

Objective To investigate the expression and role of integrin-linked kinase (ILK) in the renal tubular epithelial to mesenchymal transition (EMT) induced by TGF-β1.Methods Human kidney proximal tubular cell line (HKC) was cultured in vitro.Cells were then treated with TGF-β1 at different concentrations.ILK,α-smooth muscle actin (α-SMA),fibronectin (FN) and E-cadherin expression in protein and mRNA level were detected by Western blotting and real-time RT-PCR respectively.Results (1)Western blot analysis revealed that TGF-β1 significantly induced ILK and α-SMA protein expression in HKC cells in a dose- and time-dependent manner.Real-time RT-PCR analysis illustrated that expression for ILK mRNA,α-SMA mRNA,and FN mRNA were significantly increased,while E-cadherin mRNA was markedly decreased in a dose- and time-dependent manner in HKC cells after stimulation by TGF-β1.(2)Correlation analysis:expression of ILK protein was positively correlated with α-SMA protein (r=0.940,P<0.01);expression of ILK mRNA was positively correlated with expression of α-SMA mRNA and FN mRNA (r=0.926,r=0.915,P<0.01),while was negatively correlated with the E-cadherin mRNA expression (r=-0.820,P<0.01).Conclusions ILK plays a crucial role in regulating TGF-β1 mediated renal tubular EMT.