艾塞那肽对高糖诱导INS-1细胞内质网应激及JNK信号通路的影响

Effects of Exendin-4 on Endoplasmic Reticulum Stress Induced by High Glucose and JNK Signaling Pathway in INS-1 Cells

目的探讨艾塞那肽对高糖诱导INS-1细胞的内质网应激(ERS)及对JNK信号通路的影响。方法小鼠INS-1细胞按不同的处理方式分为4组:对照组(A组,完全培养基)、高糖组(B组,30mmol/L糖培养基)、高糖+100nmol/L艾塞那肽组(C组)、高糖+100nmol/L艾塞那肽+JNK激动剂组(D组)。每天换液前观察各组细胞生存状态,培养7天后,MTT法检测细胞活性;提取细胞总蛋白,Western blot法检测Bip、CHOP、P-SAPK/JNK、caspase-3蛋白的表达水平。结果培养至第4天B组细胞出现死亡,培养至第6、7天B组及D组细胞出现大量死亡;与A组比较,B组和D组的活性(A值)下降(P <0. 05);与A组比较,B组高糖刺激后导致内质网应激上调Bip、CHOP、P-SAPK/JNK、caspase-3的表达量(P <0. 05);与B组比较,C组艾塞那肽可通过抑制内质网应激下调Bip、CHOP、P-SAPK/JNK、caspase-3表达量(P <0. 05);与C组比较,D组JNK激动剂促进JNK信号通路上调P-SAPK/JNK、caspase-3表达量(P <0. 05)。结论艾塞那肽可以缓解或阻断高糖刺激诱发的INS-1细胞内质网应激(ERS),抑制JNK信号通路,减少细胞凋亡。

Objective To explore the effects of exendin-4 on endoplasmic reticulum stress induced by high glucose and JNK signaling pathway in INS-1 cells.Methods Mouse INS-1 cells were divided into 4 groups according to different treatment methods,the control group(group A,complete medium),high glucose group(group B,30mmol/L glucose medium),high glucose+100nmol/L exendin-4 group(group C),high glucose+100nmol/exenatide-4+JNK agonist(group D).We observed the survival status of each group in every day.After cultured for 7 days,cell survival was assessed by MTT staining.Total cellular protein was extracted.We used Western blot to detect the expression of Bip,CHOP,P-SAPK/JNK and caspase-3.Results After the fourth day of culture,the cells in group B start died,and a large number of cell deaths occurred in groups B and D until the sixth and seventh days.Compared with group A,the cell activity of group B and group D decreased(P<0.05).Compared with group A,the group B up-regulated the expression of Bip,CHOP,P-SAPK/JNK and caspase-3(P<0.05).Compared with group B,group C down-regulated the expression of Bip,CHOP,P-SAPK/JNK and caspase-3(P<0.05).Compared with group C,group D promoted JNK signaling upregulate the expression of P-SAPK/JNK and caspase-3(P<0.05).Conclusion Exendin-4 can ameliorate or block INS-1 cell endoplasmic reticulum stress(ERS)induced by high glucose,inhibit JNK signaling pathway and reduce cell apoptosis.