摘要
Abstract
Objective To investigate the protective effect of GLP-1 on H 2 O 2-induced oxidative stress damage in rat islets and its potential mechanism. Methods Pancreatic islets were isolated and purified from SD rat by Ficoll method. Three of experi-mental groups were involved:normal control group, H 2 O 2 induced islet injury group, and islets pretreated with GLP-1 plus H 2 O 2 injury group. The survival rate of islets was measured by FDA/PI fluorescent staining. The apoptosis rate of islets was determined by flow cytometry with Annexin-V/PI staining. The mRNA levels of oxidative stress and apoptosis-related genes including iNOS, SOD2, Caspase-3 and Bcl-2 were detected by real-time PCR. The protein expression of Akt, P-Akt, and caspase-3 in islets was analyzed by western blot. The protective effect of GLP-1 against oxidative stress and β-cell apoptosis was investigated, and the change of PI3K/Akt signaling pathway was also observed. Results After addition of H 2 O 2 , the proliferation, survival rate and glucose-stimulated insulin secretion of islets were significantly decreased with, while the apoptosis rate of islet was significantly in-creased. The mRNA levels of iNOS and Caspase-3 were significantly increased, while mRNA levels of SOD and Bcl-2 were signifi-cantly decreased. The phosphorylation of Akt was markedly decreased, while the activity of caspase-3 was markedly elevated. In contrast, pretreatment of GLP-1 significantly improved islets proliferation, survival and insulin secretion, and significantly reduced islets apoptosis. The mRNA levels of iNOS and caspase-3 were significantly decreased, while SOD level was significantly in-creased. The phosphorylation of Akt was markedly enhanced, while the protein level of cleaved caspase-3 was markedly de-creased. Conclusion GLP-1 was able to inhibit H 2 O 2-induced oxidative stress injury in rat islets, and its effect mechanism re-lated to the enhancement of Akt phosphorylation and the deactivation of apoptosis signaling molecules.关键词
GLP-1/胰岛/氧化应激/细胞凋亡/Akt磷酸化Key words
glucagon like peptide-1/islet,oxidative stress/apoptosis/Akt phosphorylation分类
医药卫生
