中文摘要：

目的 研究鸢尾素（irisin）对C2C12细胞葡萄糖摄取的影响及机制。方法 将C2C12细胞分为： Control组，不同浓度的irisin组（分为0.1 μg/ml,0.3 μg/ml和1 μg/ml组），高糖/高脂（HG/HF）处理组，HG/HF＋不同浓度的irisin组（分为0.1 μg/ml,0.3 μg/ml和1 μg/ml组），Control＋Scramble siRNA组，HG/HF＋AMPKα2 siRNA组，HG/HF＋scramble siRNA组，HG/HF＋scramble siRNA＋irisin组，HG/HF＋AMPKα2 siRNA＋irisin组。采用荧光葡萄糖（2-NBDG）检测细胞的葡萄糖摄取；Western blot检测细胞葡萄糖转运体4（GLUT4）转位情况和AMPK磷酸化水平。结果 ①与Control组相比，HG/HF组C2C12细胞葡萄糖摄取降低（P〈0.05），不管是否经过高糖处理，Irisin均增加C2C12细胞葡萄糖摄取（P〈0.05或P〈0.01）。与Control组相比，HG/HF降低鼠骨骼肌细胞膜GLUT4表达（P〈0.01），Irisin显著增加HG/HF孵育骨骼肌细胞细胞膜GLUT4表达（P〈0.01）；②与Control组相比，HG/HF降低C2C12细胞细胞膜AMPK磷酸化水平（P〈0.05），在Control组及HG/HF组，Irisin显著增加骨骼肌细胞AMPK的磷酸化水平（P〈0.05）；③与HG/HF＋scramble siRNA＋irisin组相比，HG/HF＋AMPKα2 siRNA＋irisin转染组细胞葡萄糖摄取及细胞表面GLUT4表达均显著减少（P〈0.05或P〈0.01）。结论 Irisin通过激活AMPK促进小鼠骨骼肌细胞葡萄糖摄取。

英文摘要：

AIM To investigate the effect of irisin on glucose uptake in C2C12 myocytes and its underlying mechanism. METHODS C2C12 myocytes were divided randomly into the following groups： Control, irisin （0.1 μg/ml, 0.3 μg/ml, 1 μg/m, respectively）, HF/HG, HF/HG＋irisin （0.1 μg/ml, 0.3 μg/ml, 1 μg/ml, respectively）, Control＋scramble siRNA, HF/HG＋AMPKα2 siRNA, HF/HG＋scramble siRNA, HF/HG＋scramble siRNA＋irisin, and HF/HG＋AMPKα2 siRNA＋irisin. The phosphorylated and total AMPK and GLUT4 were determined by Western blot and the uptake of glucose was assayed by analyzing the fluorescence intensity of 2-NBDG. RESULTS irisin significantly increased glucose uptake in C2C12 myocytes in a concentration-dependent fashion both in HF/HG treated group and non-HF/HG treated group （all P〈0.05）. Compared with those in control group, HF/HG decreased the GLUT4 expression and irisin significantly increased GLUT4 expression （P〈0.05）. Compared with those in control group, HF/HG decreased the phosphorylated AMPK in C2C12 myocytes and irisin increased the phosphorylated AMPK both in HF/HG treated group and non-HF/HG treated group （P〈0.05 or P〈0.01）. AMPKα2siRNA inhibited the increase of glucose uptake and phosphorylation of AMPK induced by irisin in C2C12 myocytes （P〈0.05 or P〈0.01）. CONCLUSION Irisin increases glucose uptake in myocytes and skeletal muscle by activating AMPK.