摘要：
目的 研究胰高糖素样肽-1(GLP-1)受体激动剂利拉鲁肽对小鼠胰岛β细胞系Min6细胞产生成纤维细胞生长因子-21(FGF-21)的调控作用及其潜在机制.方法 培养Min6细胞,在添加或不添加GLP-1受体拮抗剂exendin(9-39)的情况下,给予利拉鲁肽干预24 h后,采用实时定量聚合酶链反应(RT-PCR)和Western blotting检测细胞FGF-21 mRNA和蛋白表达,利用ELISA检测上清液FGF-21水平.在另外的实验中,Min6细胞给予10 nmol/L利拉鲁肽和(或)5 μg/ml FGF-21中和抗体孵育24 h后,ELISA法检测上清液胰岛素水平.组间比较采用单因素方差分析和LSD-t检验.结果 与对照组相比,1、10及100 nmol/L利拉鲁肽可剂量依赖性上调Min6细胞FGF-21 mRNA(分别为1.26± 0.24、1.52±0.41、1.21±0.26比1,F=3.523,P=0.021)和蛋白(分别为1.61±0.27、1.70±0.45、1.27±0.10比1, F=5.052,P=0.006)表达,增加FGF-21分泌[分别为(0.21 ± 0.05)、(0.25 ± 0.08)、(0.26 ± 0.07)比(0.19 ± 0.06)μg/mg蛋白,F=16.44,P=0.007],添加exendin(9-39)可削弱10 nmol/L利拉鲁肽的上述效应[mRNA表达水平:0.85±0.15比1.31±0.16,t=4.133,P=0.026;蛋白表达水平:1.27±0.13比1.74±0.06,t=10.55,P=0.009;分泌水平:(0.23±0.11)比(0.26±0.10)μg/mg蛋白,t=4.159,P=0.025].与对照组相比,10 nmol/L利拉鲁肽可促进Min6细胞的胰岛素分泌[(1.22±0.47)比(0.55±0.23)μg/mg蛋白,t=3.19,P=0.024],添加FGF-21中和抗体可消除该效应[(0.67±0.28)比(1.22±0.47)μg/mg蛋白,t=4.371,P=0.007].结论利拉鲁肽可呈GLP-1受体依赖性地促进小鼠β细胞系Min6的FGF-21表达和分泌,FGF-21可能以自分泌或旁分泌方式参与介导利拉鲁肽促进Min6细胞胰岛素分泌的效应.%Objective To investigate the effect and potential mechanism of glucagon-like peptide-1(GLP-1)receptor agonist liraglutide on fibroblast growth factor-21(FGF-21)production in mouse pancreatic β cell line Min6.Methods Min6 cells were incubated for 24 h with liraglutide in the presence or absence of the GLP-1 receptor antagonist exendin(9-39).The expressions of FGF-21 mRNA and protein were detected by RT-PCR and western blotting analyses. Supernatant FGF-21 levels were measured by ELISA. In the mean time, after Min6 cells were incubated with 10 nmol/L liraglutide and/or 5 μg/ml neutralizing anti-FGF-21 IgG for 24 h,supernatant insulin levels were measured by ELISA.Different group comparisons were performed using one-way variance analysis and LSD-t test. Results Compared with control group, 1, 10 and 100 nmol/L liraglutide dose-dependently upreglulated the expression levels of FGF-21 mRNA (1.26 ± 0.24,1.52 ± 0.41 and 1.21 ± 0.26 vs 1, F=3.523, P=0.021) and protein (1.61 ± 0.27, 1.70±0.45 and 1.27±0.10 vs 1,F=5.052,P=0.006),and increased the levels of FGF-21 secretion[(0.21± 0.05), (0.25 ± 0.08) and (0.26 ± 0.07) vs (0.19 ± 0.06) μg/mg, F=16.44,P=0.007] in Min6 cells. The above effects of 10 nmol/L liraglutide could be eliminated by addition of exendin(9-39)[mRNA level,0.85±0.15 vs 1.31 ± 0.16, t=4.133, P=0.026; protein level, 1.27 ± 0.13 vs 1.74 ± 0.06, t=10.55, P=0.009; secretion level,(0.23±0.11)vs(0.26±0.10)μg/mg protein, t=4.159,P=0.025].Moreover,compared with control group, 10 nmol/L liraglutide stimulated insulin secretion in Min6 cells[(1.22 ± 0.47)vs(0.55 ± 0.23)μg/mg protein,t=3.19,P=0.024],which could be abolished by blocking FGF-21 action with anti-FGF-21 IgG[(0.67± 0.28)vs (1.22 ± 0.47)μg/mg protein, t=4.371, P=0.007]. Conclusion Liraglutide enhances FGF-21 production in mouse pancreatic β cell line Min6 in a GLP-1 receptor-dependent manner.FGF-21 may be involved in the stimulating effect of liraglutide on insulin secretion from Min6 cells in an autocrine or paracrine fashion.
