毒胡萝卜素对人胚肺成纤维细胞凋亡影响及部分机制的初步探讨

目的研究内质网应激(endoplasmic reticulum stress,ERS)标识物葡萄糖调节蛋白(glucose regulated protein,GRP)和CCAAT增强子结合蛋白同源蛋白(CCAAT/enhancerbinding protein homologous protein,CHOP)在人胚肺成纤维细胞凋亡过程中的表达变化,初步探讨毒胡萝卜素对人胚肺成纤维细胞凋亡的作用及部分机制。方法体外用毒胡萝卜素(TG)诱导人胚肺成纤维细胞(MRC-5)后,采用流式细胞仪检测细胞的凋亡变化,RT-PCR检测细胞中GRP78、CHOPmRNA的表达变化,Western blot检测GRP、CHOP及Caspase-3蛋白的表达情况。结果与对照组比较,经TG作用24 h后,细胞凋亡率增加,并呈浓度依赖性,差异具有统计学意义(P<0.05)。TG组在24 h的GRP、CHOP表达均高于对照组,差异具有统计学意义(P<0.05,P<0.01);同时不同刺激组中Caspase-3的表达高于对照组,差异具有统计学意义(P<0.01)。结论毒胡萝卜素可诱导人胚肺成纤维细胞发生凋亡,该凋亡可能与ERS有关。

Effect and mechanism of thapsigargin in apoptosis in MRC-5 cells

Aim To study changes of endoplasmic retieulum stress relevant protein on the apoptosis in human fetal lung fibroblast cells(MRC-5) and explore the apoptotic effect of thapsigargin(TG) on MRC-5 through ER stress activation.Methods Apoptotic rate in MRC-5 cells was observed using flow cytometric analysis.The expression levels of GRP78,CHOP mRNA was evaluated by RT-PCR.The protein levels of GRP,CHOP,Caspase-3 were assessed by Western blot.Results The apoptotic rates of MRC-5 cells were significantly increased,and were statistically significant when compared with the control(P<0.05).GRP,CHOP mRNA and proteins levels were significantly increased when the cells were separately treated with TG for 24 h when compared with the control(P<0.05,P<0.01).Meanwhile,the protein expression of Caspase-3 in TG was also upregulated.Conclusions The elevated expression of relevant proteins when ERS occurs indicates ERS participates in the process of apoptosis in MRC-5 cells.