γ-分泌酶抑制剂对大鼠肾小管上皮细胞间充质转分化的抑制作用

Inhibitory effect of γ-secretase inhibitor on the epithelial-to-mesenchymal transition in NRK52Ecells

目的探讨γ-分泌酶抑制剂（DAtrr）对大鼠肾小管上皮（NRK52E）细胞间充质转分化（EMT）的抑制作用及机制。方法含10μg/L转化生长因子-β1（TGF-β1）的无血清培养基孵育NRK52E细胞48h构建EMT模型；或10mol/L DAprr预处理15rain后构建NRK52E细胞EMT模型。Western blot法检测NRK52E细胞Notch-1、Hes-1、α-平滑肌肌动蛋白（α-SMA）、E-钙黏素（E-cadherin）蛋白表达，小室迁移实验检测细胞迁移能力。结果TGF-βl显著上调NRK52E细胞Notch-1、Hes-1、α-SMA蛋白表达，下调E-cadherin表达，并增强细胞迁移能力[（482．87±78．23）个比（1464．164±31．82）个．P〈0．05]。DAPT可显著抑制TGF-β1诱导的NRK52E细胞Notch-1、Hes-1、E-cadherin、α-SMA蛋白表达的变化及迁移能力的增强[（509．23±83．21）个比（1493．644±463．34）个、（983．06±169．49）个，P〈0．05]。结论Notch信号通路的活化参与了TGF-β1诱导NRK52E细胞EMT，DAPT阻断Notch信号通路活性，抑制TGF-βl诱导的NRK52E细胞EMT。

Objective To explore the protective effect of γ-secretase inhibitor （DAPT） on epithe lial-to-mesenchymal transition （EMT） in NRK 52E ceils and the potential mechanism. Methods NRK52E cells were treated with 10μg/L of transforming growth factor-β1 （TGF-β1） or dimethylsurfoxide （DMSO） for 48 h, or NRK52E cells preincubated with 10μmol/L DAPT for 15 min before 10 μg/L TGF-131 treatment for 48 h. Western blotting was applied to detect the protein expression of Notch-l, Hes-1, α-smooth muscle actin （α-SMA） and E-cadherin of NRK52E cells, and transwell assay was applied to measure cell migration. Results TGF-β1 upregulated Notch-1, Hes-1 andα-SMA expression, downregu lated E-cadherin expression, and enhanced migration （482. 87 ± 78.23 vs. 1 464. 16 ± 31.82, P 〈 0. 05 ） in NRK52E ceils. DAPT treatment attenuated the degree of Notch-1, Hes-1 and α-SMA upregulation ex pression, E-cadherin suppression and migration （509. 23± 83.21, 1 493.64 ± 463.34 vs. 983.06 ± 169. 49, P 〈0. 05 for all） induced by TGF-β1 in NRK52E cells. Conclusion The Notch signaling path way activation played an important role in TGF-β1-induced EMT in NRK52E cells. DAPT inhibited Notch signaling pathway and protected NRK52E cells from TGF-β1-induced EMT.