中文摘要：

目的研究内质网应激（endoplasmic reticulumstress，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／enhancer binding 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24h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24h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。

英文摘要：

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 signifiant 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.