PI3K/Akt信号通路对肺泡上皮钠通道γ亚基表达的影响研究

Effect of PI3K/Akt signaling pathway on expression of γ-ENaC

目的探讨磷脂酰肌醇3-激酶/蛋白激酶B(PI3K/Akt)信号通路对肺泡上皮钠通道γ亚基(γ-ENaC)表达的影响。方法体外培养肺泡上皮细胞A549,分别以不同水平的胰岛素(胰岛素1~3组)、不同作用时间的胰岛素(胰岛素4~6组)和PI3K抑制剂LY294002(LY294002组)进行干预,对照组A549细胞于无血清培养基中培养。比较各组在不同条件下γ-ENaC mRNA、γ-ENaC蛋白及磷酸化Akt(p-Akt)表达的变化。结果胰岛素1~3组γ-ENaC mRNA、γ-ENaC蛋白及p-Akt相对表达水平与对照组比较,差异均有统计学意义(P<0.05)。胰岛素4~6组γ-ENaC mRNA、γ-ENaC蛋白及p-Akt相对表达水平与对照组比较,差异均有统计学意义(P<0.05)。LY294002组经胰岛素作用后γ-ENaC mRNA、γ-ENaC蛋白和p-Akt相对表达水平与对照组比较,差异均有统计学意义(P<0.05)。LY294002组经LY294002作用后γ-ENaC mRNA、γ-ENaC蛋白和p-Akt相对表达水平与胰岛素单独干预比较,差异均有统计学意义(P<0.05)。结论激活PI3K/Akt通路能上调γ-ENaC基因转录和蛋白表达水平,有益于肺水肿液的清除。

Objective To investigate the effect of PI3K/Akt signaling pathway on the expression of γ-ENaC in alveolar epithelium.Methods Alveolar epithelial cells A549 were cultured in vitro,and treated with different levels of insulin(insulin 1-3 group),insulin at different time of action(insulin 4-6 group)and PI3K inhibitor LY294002(LY294002 group)respectively.Control group A549 cells were cultured in serum-free medium.The changes of expression of γ-ENaC mRNA,γ-ENaC protein and phosphorylated Akt(p-Akt)in the different groups were compared under different conditions.Results The relative expression levels of γ-ENaC mRNA,γ-ENaC protein and p-Akt in the insulin 1-3 groups were significantly different from those of the control group(P<0.05).The relative expression levels of γ-ENaC mRNA,γ-ENaC protein and p-Akt in the insulin 4-6 groups were significantly different from those of the control group(P<0.05).The relative expression levels of γ-ENaC mRNA,γ-ENaC protein and pAkt in the LY294002 group after insulin treatment were significantly different from those in the control group(P<0.05).The relative expression levels of γ-ENaC mRNA,γ-ENaC protein and p-Akt in the LY294002 group after LY294002 treatment were significantly different from those of insulin alone intervention(P<0.05).Conclusion Activation of PI3K/Akt pathway can up-regulate the transcription and protein expression of γ-ENaC gene,which is beneficial to the clearance of pulmonary edema.