羊栖菜多糖对H_2O_2诱导胰岛β细胞凋亡的保护作用及PI3K抑制剂的影响

Reflact of PI3K Inhibiter and Procetion and Mechanism of Sargassum Fusiforme Polysaccharides for Pancreatic Beta Cells

目的:此实验设计以了解羊栖菜多糖(Sargassum Fusiforme Polysaccharides,SFPS)对胰岛β细胞的保护作用及机制。方法:采用体外H2O2诱导大鼠胰岛细胞瘤株(RINm5F)凋亡,MTT法检测SFPS对RINm5F的活性影响,运用分光光度法检测SFPS对RINm5F和原代大鼠胰岛的SOD、MDA的影响。结果:0.2mmol/LH2O2诱导RINm5F凋亡,Hoechst3342/PI见典型的凋亡,30μmol/LPI3K抑制剂LY294002与H2O2有协同致细胞损伤作用;20μg.ml-1SFPS保护H2O2对RINm5F活性的损伤,LY294002预处理1h不能阻断其保护作用;模型组RINm5F和原代大鼠胰岛细胞内SOD下降;SFPS能提高RINm5F和原代大鼠胰岛的SOD活性,LY294002预处理阻断SFPS提高抗氧化酶活性的作用。结论:H2O2可导致胰岛细胞凋亡,使细胞和组织的抗氧化酶活性下降,与PI3K-Akt通路抑制剂有协同作用,一定浓度和时间SFPS可减少H2O2诱导的胰岛细胞凋亡,增加细胞和组织抗氧化酶SOD的活性,PI3K-Akt抑制剂可阻断SFPS抗氧化作用,但不能最终抑制SFPS对胰岛细胞数量和活性的保护作用,说明SFPS对胰岛细胞的保护作用可能还存在除PI3K-Akt通路以外的其他通路。

Objective： Reserch was designed for the procetion and mechanism of SFPS （ Sargassum Fusiforme Polysaccharides） for pancreatic beta cells. Methods ：We made cell apoptoais models of RINm.SF and pancreatic islets induced by H2O2. Detecting the cells vitality and proliferation by MTT method. Results ： SOD were checked out by visible spectrophotometry method. We found 0. 2mmol/L H2O2 make the vitality of RINmSF redued,and typical cell apoptosis was observed by Hoechst/PI staining. What＇s more,30panol/L phosphatidyl - 3 - kinases （PI3K） inhibitor LY294002 had synergism with H2O2 on cell damage. 20μg·mL^-1 SFPS had a protection for RINmSF against the damage,where pre-disposal of LY294002 couldnt block up. SFPS elevated cellular SOD activity of RINmSF and pancreatic islets which was turned down in model groups, but the effect was blocked up by pre-disposal of LY294002. Conclusion： We concluded that H2O2 induced pancreatic beta cells apoptosis vartly by reducing the SOD activity mediated by PI3K signal passage. SFPS protected pancreatic beta cells against H2O2 injury,and increased the SOD activity which could be blocked up by PI3K-inhibitor. The protection of SFPS had relationship with multiple signal passages except for PI3K signal passage.