司美格鲁肽改善棕榈酸诱导C2C12骨骼肌细胞萎缩的机制研究

Semaglutide ameliorates palmitic acid-induced C2C12 skeletal muscle cell atrophy

目的探讨胰升糖素样肽-1受体激动剂(GLP-1RA)司美格鲁肽改善棕榈酸诱导C2C12骨骼肌细胞萎缩的机制。方法C2C12细胞分为对照组、0.5 mmol/L棕榈酸组、0.5 mmol/L棕榈酸+15 nmol/L司美格鲁肽组、0.5 mmol/L棕榈酸+90 nmol/L司美格鲁肽组及0.5 mmol/L棕榈酸+900 nmol/L司美格鲁肽组,CCK-8检测各组细胞存活率,2-NBDG荧光探针检测各组细胞葡萄糖摄取情况,免疫荧光法检测肌管直径,Western印迹法检测葡萄糖转运蛋白4(GLUT4)、磷酸化蛋白激酶B(p-Akt)、Ⅲ型纤维连接蛋白结构域5(FNDC-5)、肌球蛋白重链(MHC)、肌细胞生成素(MyoG)、肌肉萎缩盒F基因(Atrogin-1)及肌肉环状指基因1(MuRF-1)蛋白的表达水平。结果与对照组相比,棕榈酸组细胞存活率及葡萄糖摄取均明显降低,肌管直径减小,p-Akt、GLUT4、FNDC-5、MHC及MyoG蛋白表达水平显著下降,Atrogin-1及MuRF-1表达显著升高(均P<0.05),15、90和900 nmol/L司美格鲁肽增加细胞存活率、葡萄糖摄取和肌管直径,以及p-Akt、GLUT4、FNDC-5、MHC和MyoG的蛋白表达水平,降低Atrogin-1及MuRF-1蛋白表达(均P<0.05)。结论司美格鲁肽可改善棕榈酸诱导的C2C12细胞胰岛素抵抗,并通过促进肌细胞合成、抑制肌细胞降解,改善肌细胞萎缩,FNDC-5可能参与其中。

Objective To investigate the role of glucagon-like peptide-1 receptor agonist(GLP-1RA)semaglutide in palmitic acid-induced atrophy of mouse C2C12 skeletal muscle cells.Methods C2C12 cells were divided into control group,0.5 mmol/L palmitate group,0.5 mmol/L palmitate plus 15 nmol/L semaglutide group,0.5 mmol/L palmitate plus 90 nmol/L semaglutide group,and 0.5 mmol/L palmitate plus 900 nmol/L semaglutide group.C2C12 cell survival rate was detected with the CCK8 method and 2-NBDG fluorescent probe was used to evaluate the glucose uptake of cells in each group.The diameter of myotubes were measured by immunofluorescence.The protein expressions of glucose transporter 4(GLUT4),phosphorylated protein kinase B(p-Akt),typeⅢdomain-containing protein 5(FNDC-5),myosin heavy chain(MHC),myogen(MyoG),the muscular atrophy box F gene(Atrogin-1),and muscle ring finger gene 1(MuRF-1)were assessed by Western blot.Results Compared with the control group,palmitate group showed significant decreases in the cell survival rate,glucose uptake,the diameter of myotubes,p-Akt,GLUT4,FNDC-5,MHC,and MyoG protein expression levels,while increased expressions of Atrogin-1 and MuRF-1(all P<0.05).The treatment of 15,90,and 900 nmol/L semaglutide significantly increased the cell viability,glucose uptake,and the diameter of myotubes as well as p-Akt,GLUT4,FNDC-5,MHC,and MyoG protein expression levels,and decreased Atrogin-1 and MuRF-1 expressions(all P<0.05).Conclusion Semaglutide improves palmitic acid-induced insulin resistance of C2C12 cells and attenuates muscle cell atrophy by promoting muscle cell synthesis and inhibiting muscle cell degradation,in which FNDC-5 may be involved.