胰高血糖素样肽-1模拟肽对大鼠胰岛RINm5F细胞增殖、凋亡及胰岛素分泌的影响

目的观察胰高血糖素样肽-1(Glucagon-like peptide-1,GLP-1)模拟肽对大鼠胰岛RINm5F细胞增殖、凋亡及胰岛素分泌的影响。方法将RINm5F细胞分为GLP-1组(加入30nmol/LGLP-1)、GLP-1模拟肽组(分别加入15、30和50nmol/LGLP-1模拟肽)和空白对照组,MTT法检测各组细胞的增殖情况;在不同浓度葡萄糖(4.5和20mmol/L)培养条件下,采用ELISA Kit检测各组细胞胰岛素的分泌情况;葡萄糖加棕榈酸诱导RINm5F细胞凋亡,检测各组细胞的存活率,并用RT-PCR检测各组细胞凋亡相关基因bcl-2和bax的表达。结果 GLP-1模拟肽可呈浓度依赖性地刺激RINm5F细胞增殖;可促进RINm5F细胞分泌胰岛素,这种作用随环境中葡萄糖浓度的增加而增强;与凋亡模型组比较,GLP-1模拟肽组细胞存活率增加,bcl-2基因表达增加,bax基因表达量无明显变化。结论 GLP-1模拟肽可以促进RINm5F细胞增殖和分泌胰岛素,并抑制RINm5F细胞凋亡。

Effects of Glucagon-like Peptide-1 Mimetic Peptide on Proliferation,Apoptosis and Insulin Secretion of RINm5F Cells

Objective To investigate the effects of glucagon-like peptide-1(GLP-1)mimetic peptide on the proliferation,apoptosis and insulin secretion of RINm5F cells.Methods RINm5F cells were divided into five groups and treated with 30 nmol/L GLP-1,15,30 and 50 nmol/L GLP-1 mimetic peptide and 200 μl of medium(blank control)respectively,and determined for proliferation by MTT method.The insulin secretion of cells in various groups at glucose concentrations of 4.5 and 20 mmol/L were determined by ELISA kit.The apoptosis of RINm5F cells were induced by glucose and palmitic acid,and the survival rates of cells in various groups were determined.The expressions of apoptosis-related genes bcl-2 and bax in RINm5F cells of various groups were determined by RT-PCR.Results GLP-1 mimetic peptide stimulated the proliferation of RINm5F cells in a concentration-dependent mode.The stimulatory effect of GLP-1 mimetic peptide on insulin secretion of RINm5F cells was enhanced with the increasing glucose concentration.Compared with those in apoptosis model group,the survival rate and the expression level of bcl-2 gene of cells treated with GLP-1 mimetic peptide increased,while the expression level of bax gene showed no significant change.Conclusion GLP-1 mimetic peptide promoted the proliferation and insulin secretion while inhibited the apoptosis of RINm5F cells.