Klotho对FGF2诱导的肾小管上皮细胞上皮-间充质转分化的抑制作用

Inhibition of Klotho on epithelia-mesenchymal transition of renal tubule epithelial cells induced by FGF2

目的探讨Klotho抑制成纤维细胞生长因子2(fibroblast growth factor2,FGF2)诱导的肾小管上皮细胞(HK-2)上皮-间充质转分化(epithelia-mesenchymal transition,EMT)的作用及机制。方法重组人Klotho蛋白预孵育前后,倒置显微镜观察FGF2对HK-2细胞形态的影响,免疫荧光检测上皮细胞标志物cytokeratin和间充质细胞标志物vimentin的表达变化,Western blot检测α-SMA、E-cadherin和ERK1/2的表达变化。结果 100 ng/mL的FGF2作用于HK-2细胞48 h后,HK-2细胞变成长梭形,细胞间隙明显增大,上皮细胞标志物E-cadherin的表达明显下降,间充质细胞标志物α-SMA表达明显升高(P<0.05),提示FGF2可以诱导HK-2细胞发生EMT。而Klotho蛋白预孵育可以显著抑制FGF2诱导的EMT,并且FGF2/FGFR(FGFs受体)下游信号分子pERK1/2的表达明显减弱(P<0.05)。结论 Klotho可以通过减弱FGF2信号通路活化抑制FGF2诱导的HK-2细胞EMT,Klotho可能参与了肾间质纤维化的发生和发展。

Objective To determine the effect and mechanism of Klottlo on ttle epittlelia-mesenchymal transition （EMT） of HK-2 cells induced by fibroblast growth factor 2 （FGF2）. Methods The effect of FGF2 on HK-2 cells morphology with and without pie-incubation of Klotho was observed. The expression levels of epithelial marker cytokeratin and mesenchymal marker vimentin were detected by immunofluorescenee, and the expression levels of （x-smooth muscle actin （（x-SMA） , E-cadherin and ERKl/2 were detected by Western blot- ting. Results After incubated with FGF2 （100 ngmL） for 48 h, HK-2 cells turned into long-spiralled shape, and the intercellular space markedly increased. The expression of epithelial marker E-cadherin signifi- cantly decreased （P 〈 0.05 ） , while the mesenchyma/ marker （x-SMA increased （ P 〈 O. 05 ） , indicating that FGF2 could induce EMT in HK-2 cells. The pre-incubation of Klotho could markedly inhibit the EMT induced by FGF2 and the expression of pERK1/2 in HK-2 cells （P 〈 0.05 ）. Conclusion Klotho can inhibit FGF2- induced EMT ia attenuating the activation of FGF2 signaling pathway, and may participate in the （levelopment of renal interstitial fibrosis.