棕榈酸诱导小鼠精原细胞株GC-1细胞凋亡的作用机制

Mechanism of palmitic acid-induced apoptosis in GC-1 cells

目的从内质网应激(endoplasmic reticulum stress,ERS)角度探讨棕榈酸(palmitic acid,PA)诱导小鼠精原细胞株GC-1细胞凋亡的机制。方法将GC-1细胞分为正常组(Control)、溶剂对照组(Vehicle)和不同浓度PA处理组(100、150、200、250μmol·L^(-1))。MTT法检测细胞增殖活力,流式细胞术Annexin V-FITC/PI双染法检测细胞凋亡情况;Caspaes-3活性检测试剂盒检测凋亡蛋白caspase-3的活性;Western blot检测凋亡相关蛋白和ERS相关蛋白表达水平。结果PA处理GC-1细胞48 h后,细胞增殖活力显著下降,细胞凋亡率上升,凋亡蛋白caspase-3活性增高,结果均具有浓度依赖性;PA可明显增加GC-1细胞促凋亡蛋白cleaved-caspase-3的表达水平,明显降低抑凋亡蛋白BCL2的表达水平,同时上调ERS相关蛋白GRP78、CHOP、p-IRE1、XBP1的表达水平,但对p-PERK、PERK、p-eIF2α、eIF2α、ATF4以及ATF6的表达无显著影响。结论PA诱导小鼠GC-1细胞凋亡可能与激活IRE1通路有关。

Aim To explore the mechanism of palmitic acid(PA)-induced apoptosis of GC-1 cells through endoplasmic reticulum stress(ERS).Methods GC-1 cells were treated with or without different concentrations of PA(0,100,150,200,250μmol·L^(-1)).The cell viability was detected by MTT assay;the cell apoptosis rate was detected by flow cytometry;the activity of caspase-3 was detected by caspase-3 activity assay kit;the levels of apoptosis and ERS-related proteins were detected by Western blot.Results After 48 h,the viability of GC-1 cells was significantly reduced,whereas the apoptosis rate and the activity of apoptosis-related protein caspase-3 remarkably rose in PA-treated cells in a concentration-dependent manner.In addition,PA significantly increased the expression levels of cleaved caspase-3 and decreased the expression levels of BCL2.Furthermore,PA remarkably up-regulated the expression levels of ERS-related proteins(GRP78,CHOP,p-IRE1 and XBP1).Conclusion PA induces apoptosis of GC-1 cells by activating IRE1 signaling pathways.