高氧对胎鼠肺Ⅱ型上皮细胞EGF、TGFβ1信号通路的影响

摘要

Objective To study imbalance between EGF and TGFβ1 signal in fetal rat alveolar epithelial type 2 cell exposed to oxygen.Methods Primary fetal rat type 2 alveolar epithelial cells were divided into air group and O2 group.Cell apoptosis was measured by FACS.Sprouty2, EGF receptor, phospho-EGF receptor( Tyr1148), phosphoEGF receptor( Tyr845 ) and TGF-βⅡ receptor were tested by Western blot.Sprouty2 mRNA was measured by realtime PCR.Results Compared with air group, there was increased cell apoptosis in O2 group according to FACS.Sprouty2 mRNA and protein were increased in O2 group.EGF receptor,phospho-EGF receptor( Tyrl148 ) ,phosphoEGF receptor( Tyr845 ) were decreased in O2 group compared with air group while TGF-βⅡ receptor expression was increased in O2 group compared with air group.Conclusion EGF which can decrease Sprouty2 expression is downregulated in fetal rat alveolar epithelial type 2 cells exposed to oxygen.TGFβ1 which can increase Sprouty2 expression is upregulated in fetal rat alveolar epithelial type 2 cell exposed to oxygen.Both of these 2 mechanisms canse further rising of Sprouty2.%目的 研究高浓度氧对胎鼠肺泡Ⅱ型上皮细胞(AECⅡ)EGF、TGFβ1信号通路及呼吸抑制拮抗基因Sprouty2表达的影响.方法 将原代培养的胎鼠AECⅡ随机分为空气和高氧两个组,观察细胞形态学变化;Annexin V和PI双标记流式细胞仪检测细胞凋亡;实时定量PCR法检测细胞Sprouty2 mRNA的表达;Western blot法检测细胞Sprouty2、EGF受体、磷酸化EGF受体(Tyr1148)、磷酸化EGF受体(Tyr845)、TGF-8Ⅱ型受体蛋白表达.结果 AECⅡ暴露于高氧后,细胞贴壁不紧,长势欠佳.高氧组早期凋亡细胞明显增多(P＜0.05);高氧暴露后24和36 h,Sprouty2 mRNA及蛋白表达随高氧暴露时间延长而增加(P＜0.05);高氧暴露后24和36 h,EGF受体、磷酸化EGF受体(Tyr1148)、磷酸化EGF受体(Tyr845)表达均减少,而TGF-βⅡ型受体蛋白表达增加(P＜0.05).结论 高氧暴露通过下调EGF信号和上调TGFβ1信号,进而使Sprouty2表达增加,增加的Sprouty2与AECⅡ凋亡相关.