胰岛素生长因子1(IGF-1)通过S1P/S1PR1信号激活PI3K通路促进小鼠肺泡上皮细胞迁移

IGF-1 activates the PI3K pathway through S1P/S1PR1 signaling to promote the migration of mouse alveolar epithelial cells

目的探讨胰岛素样生长因子1(IGF-1)对肺泡上皮细胞(AEC)迁移的影响及其相关机制。方法在磷脂酰肌醇3激酶(PI3K)抑制剂渥曼青霉素(Wortmannin)存在与否的情况下,采用IGF-1、鞘氨醇1磷酸(S1P)刺激AEC后,划痕愈合实验检测MLE-12小鼠AEC的迁移,Western blot法检测磷酸化的蛋白激酶B(p-AKT)的表达。采用IGF-1刺激AEC后,ELISA检测S1P的分泌,Western blot法检测其蛋白表达。阻断实验中,AEC S1P受体1(S1PR1)干扰或受S1PR1阻断抗体作用后,划痕实验检测IGF-1对细胞迁移的影响,Western blot法检测p-AKT蛋白表达。结果IGF-1刺激12 h后,AEC的p-AKT表达增加,细胞迁移加快;阻断PI3K信号后,IGF-1促进AEC迁移效应部分消失。IGF-1诱导AEC产生S1P,S1P通过S1PR1加快AEC迁移;S1P刺激AEC后p-AKT表达增强,阻断PI3K通路后,S1P加快AEC迁移的能力降低。AEC预先被阻断S1PR1或S1PR1干扰后,IGF-1加快AEC迁移和促进AEC p-AKT表达的效应被部分降低。结论IGF-1通过S1P-S1PR1信号激活PI3K通路促进AEC迁移。

Objective To investigate the effect of insulin-like growth factor 1(IGF-1) on the migration of alveolar epithelial cells(AECs) and its related mechanisms. Methods The MLE-12 cells(mouse AEC line) were stimulated by IGF-1 and sphingosine 1 phosphate(S1P) in the presence or absence of the PI3K inhibitor Wortmannin. Then, the cell migration was detected by the scratch test and the expression of p-Akt was detected by Western blot. With AECs stimulated by IGF-1, the secretion and expression of S1P were tested by ELISA and Western blot respectively. In the blocking experiment, the effect of IGF-1 on cell migration or p-Akt expression was detected by scratch test or Western blot after the interference of AEC S1P receptor 1(S1PR1) or the action of S1PR1 blocking antibody. Results After 12 hours of IGF-1 stimulation, the expression of p-Akt in AECs increased and the migration of AECs accelerated. When blocking PI3K signal, the effect of IGF-1 on promoting AEC migration was partially eliminated. IGF-1 induced AECs to produce S1P, which accelerated AEC migration through S1PR1. The expression of p-Akt in AECs increased after S1P stimulation. When blocking the PI3K pathway, the ability of S1P to accelerate the migration of AECs was reduced. When S1PR1 in AECs was blocked or interfered, the effect of IGF-1 on accelerating AEC migration and promoting AEC p-Akt expression was partially reduced. Conclusion IGF-1 activates the PI3K pathway through S1P-S1PR1 signal to promote the migration of AECs.