CAJ | 학술논문

目的探讨肌肉生长抑制素前肽(myostatin propeptide,MPRO)对C2C12成肌细胞葡萄糖摄取、氧化及糖原合成的影响及其作用机制.方法诱导成熟的C2C12成肌细胞分为对照组、胰岛素组、绿色荧光蛋白(GFP)组、胰岛素+GFP组、MPRO组及胰岛素+MPRO组,经相应处理后应用2-脱氧-右旋-[1-14C]葡萄糖检测MPRO对C2C12细胞葡萄糖摄取、氧化及糖原合成的影响,应用Western印迹法检测胰岛素信号通路活性.结果与对照组相比,胰岛素组及胰岛素+GFP组葡萄糖摄取及糖原合成量明显增加(P＜0.05);胰岛素+ MPRO组C2C12细胞葡萄糖摄取量及糖原合成较胰岛素组显著增加(P＜0.05);但MPRO及胰岛素对葡萄糖的氧化无明显影响(P＞0.05).Western印迹结果显示,与对照组相比,胰岛素组及胰岛素+GFP组胰岛素信号通路中的信号分子胰岛素受体β(IRβ)、胰岛素受体底物1(IRS-1)、蛋白激酶B(Akt)、糖原合成酶激酶3β(GSK-3β)磷酸化水平及磷脂酰肌醇3激酶(PI3K)、细胞膜葡萄糖转运体4(Glut4)的表达显著增高(P＜0.05),转染MPRO后上述基因的蛋白磷酸化和表达水平升高更显著(P＜0.05).结论 MPRO在C2C12可能通过激活IRS-1/PI3K/Akt信号通路增加胰岛素刺激的葡萄糖摄取及糖原合成.
목적 탐토기육생장억제소전태(myostatin propeptide,MPRO)대C2C12성기세포포도당섭취、양화급당원합성적영향급기작용궤제.방법 유도성숙적C2C12성기세포분위대조조、이도소조、록색형광단백(GFP)조、이도소+GFP조、MPRO조급이도소+MPRO조,경상응처리후응용2-탈양-우선-[1-14C]포도당검측MPRO대C2C12세포포도당섭취、양화급당원합성적영향,응용Western인적법검측이도소신호통로활성.결과 여대조조상비,이도소조급이도소+GFP조포도당섭취급당원합성량명현증가(P＜0.05);이도소+ MPRO조C2C12세포포도당섭취량급당원합성교이도소조현저증가(P＜0.05);단MPRO급이도소대포도당적양화무명현영향(P＞0.05).Western인적결과현시,여대조조상비,이도소조급이도소+GFP조이도소신호통로중적신호분자이도소수체β(IRβ)、이도소수체저물1(IRS-1)、단백격매B(Akt)、당원합성매격매3β(GSK-3β)린산화수평급린지선기순3격매(PI3K)、세포막포도당전운체4(Glut4)적표체현저증고(P＜0.05),전염MPRO후상술기인적단백린산화화표체수평승고경현저(P＜0.05).결론 MPRO재C2C12가능통과격활IRS-1/PI3K/Akt신호통로증가이도소자격적포도당섭취급당원합성.
Objective To investigate the effects of recombinant adeno-associated virus-mediated myostatin propeptide (MPRO) on uptake and oxidation of glucose,and glycogen synthesis in C2C12 myotubes,as well as the associated molecular mechanism.Methods Mature C2C12 myotubes were assigned to the following 6 groups:control,insulin,green fluorescent protein (GFP),insulin + GFP,MPRO,and insulin + MPRO groups.Glucose uptake,glucose oxidation,and glycogen synthesis were detected by counting radioactivity of 14CO2 or 14C labeled glycogen derived from 2-deoxy-[1-14 C] glucose.The activity of insulin signal pathway was evaluated by Western blot.Results Compared with control group,glucose uptake and glycogen synthesis were significantly increased in insulin and insulin+GFP groups,and further increased in insulin+MPRO group as compared with insulin alone(all P＜ O.05).However,MPRO and insulin had no effect on glucose oxidation.The phosphorylations of insulin receptor (IR) β,insulin receptor substrate 1 (IRS-1),protein kinase B (Akt),glycogen synthase kinase-3 β (GSK-3β),and the expressions of phosphatidylinositol 3-kinase (PI3K) and glucose transporter 4 (Glut4) in membrane were significantly increased in insulin and insulin+GFP groups compared with control group(all P＜0.05),and were further increased after MPRO transfection (all P ＜ 0.05).Conclusion MPRO may increase insulin-stimulated glucose uptake and glycogen synthesis in C2C12 cells by activating the IRS/PI3K/Akt signal pathway.