上调整合素连接激酶可抑制肾小管上皮细胞E-cadherin表达

摘要

Objective To study the effect of up-regulated integerin-linked kinase (ILK) on expression of E-cadherin in human kidney tubular cells (HKC).Methods ILK was transfected into the HKC and over-expressed in HKC. Effect of ILK on expression of E-cadherin and activity of GSK-3β in HKC was detected by RT-PCR, Western blot and immunofluorescence techniques, respectively. Effect of SB415286, an inhibitor of GSK-3β, on expression of E-cadherin was further observed. Results The over-expression of ILK could significantly inhibit the expression of E-cadherin and up-regulate the activity of GSK-3β. The expression of E-cadherin after SB415286 treatment was down-regulated. Immunofluorescenceshowed that over-expression of ILK could lead to polar change of HKC and down-regulate the expression of E-cadherin in HKC.Conclusion ILK inhibits the expression of E-cadherin in HKC by up-regulating the activity of GSK-3β, thus inducing epithelial-mesenchymal transition of tubular epithelial cells.%目的：研究上调整合素连接激酶(integerin-linked kinase，ILK)对肾小管上皮细胞(human kidney tubular cells，HKC) E-钙黏素(E-Cadherin)表达的影响。肾小管上皮细胞转分化(epithelial-mesenchymal transition，EMT)在肾间质纤维化中发挥重要作用。E-Cadherin是维持肾小管上皮细胞极性的关键蛋白。ILK是调控上皮细胞转分化的重要蛋白，其作用机制目前还不清楚。方法本研究中我们将ILK转染到HKC中过表达，然后用RT-PCR、Western blot及免疫荧光方法观察了ILK对E-Cadherin表达及糖原合成激酶-3β(glycogen synthase kinase 3β，GSK-3β)活性的影响。进一步用磷酸化下游底物GSK-3β抑制剂SB415286观察对E-Cadherin表达的影响。结果 ILK过表达可以明显抑制E-Cadherin表达,增加GSK-3β活性。用GSK-3β抑制剂处理后可以下调E-Cadherin的表达。免疫荧光显示ILK过表达可使上皮细胞发生极性改变， E-Cadherin表达下调。表明ILK上调可通过激活GSK抑制E-Cadherin表达，进而诱导肾小管上皮细胞出现转分化表型。