C-型凝集素域家族11成员A促进胰岛素分泌改善脂毒性诱导胰岛损伤的研究

C-type lectin domain family 11 member A promotes insulin secretion and ameliorates lipotoxicity-induced islet injury

目的探讨脂毒性对胰岛C-型凝集素域家族11成员A(Clec11a)表达的影响,重组Clec11a(rClec11a)蛋白对小鼠胰岛、小鼠胰岛β细胞系MIN6细胞及人胰岛β细胞系EndoC-βH1细胞胰岛素分泌的影响。方法免疫荧光染色检测正常小鼠(Con)及高脂饲料喂养的肥胖小鼠(DIO)胰岛Clec11a与胰岛素表达。采用棕榈酸(PA)干预正常小鼠胰岛及MIN6细胞不同时间,Western blot检测Clec11a蛋白表达。将分离的正常小鼠胰岛分为磷酸盐缓冲液(PBS)对照组及不同浓度rClec11a处理组,检测胰岛素刺激指数(SI)。将分离的正常小鼠胰岛分为载体对照组(Con-Veh组)、Con-PA组和Con-PA+rClec11a组,检测胰岛素SI。将EndoC-βH1细胞分为PBS对照组(EndoC-βH1-PBS组)与rClec11a干预组(EndoC-βH1-rClec11a组)及siRNA-Negtive Con组与siRNA-Clec11a干预组,分别检测高糖刺激后胰岛素分泌。结果DIO小鼠胰岛Clec11a表达低于正常小鼠。小鼠胰岛及MIN6细胞内Clec11a蛋白表达随PA培养时间延长呈先升高后降低趋势(P<0.05)。与Con-PBS组比较,Con 10 rClec11a、Con 100 rClec11a、Con 1000 rClec11a组SI升高(P<0.05)。与Con-Veh组比较,Con-PA组SI降低(P<0.05)。与Con-PA组比较,Con-PA+rClec11a组SI升高(P<0.05)。20 mmol/L高糖刺激30 min后,EndoC-βH1-rClec11a组胰岛素分泌高于EndoC-βH1-PBS组(P<0.05),siRNA-Clec11a组胰岛素分泌低于siRNA-Negtive Con组(P<0.05)。结论高脂培养下胰岛Clec11a表达降低,Clec11a通过促进胰岛β细胞分泌胰岛素,对脂毒性诱导的胰岛损伤发挥保护作用。

Objective To investigate the effect of lipotoxicity on C-type lectin domain family 11member A(Clec11a)expression in islets,as well as the effect of recombination Clec11a on insulin secretion in mice islets,MIN6 cells and EndoC-βH1 cells.Methods Clec11a and Ins expressions were verified by immunofluorescence staining in islets of mice in control group(Con)and high fat diet induced obesity group(DIO).Islets of normal mice and MIN6 cells were cultured with palmitic acid(PA)for different times.Western blot was used to detect Clec11a expression.Islets of normal mice were divided into PBS treated control group and different concentration of rClec11a treated groups.SI was tested in each group.Islets of normal mice were divided into Con-Veh group,Con-PA group and Con-PA+rClec11a group,and SI was measured.EndoC-βH1 cells were divided into EndoC-βH1-PBS group and EndoC-βH1-rClec11a group,as well as siRNA-Negtive Con and siRNA-Clec11a group,and high glucose stimulated Ins secretion was tested.Results Clec11a expression was lower in DIO mice islets than in Con group.Clec11a expression was increased at first and then decreased in islet and MIN6 cells treated with PA(P<0.05).SI was higher in Con 10 rClec11a,Con 100 rClec11a,and Con 1000 rClec11a groups than in Con-PBS group(P<0.05).SI was significantly lower in Con-PA group than in Con-Veh group(P<0.05).SI was significantly higher in Con-PA+rClec11a group than in Con-PA group(P<0.05).The Ins secretion was higher in EndoC-βH1-rClec11a cells than in EndoC-βH1-PBS group(P<0.05),while lower in siRNA-Clec11a group than in siRNA-Negtive Con group after 20 mmol/L high glucose stimulation for 30 min(P<0.05).Conclusion Islet injury induced by lipotoxicity is accompanied by decreased Clec11a expression.Clec11a plays a protective role against islet injury by promoting Ins secretion inβcells.