Gray Stuart R, Ratkevicius Aivaras, Wackerhage Henning, Coats Paul, Nimmo Myra A
Department of Sport & Exercise Sciences, Loughborough University, Ashby Road, Loughborough, Leicestershire LE113TU, UK.
Exp Physiol. 2009 Aug;94(8):899-905. doi: 10.1113/expphysiol.2009.048173. Epub 2009 May 29.
Exercise results in an increase in interleukin-6 (IL-6), its receptor (IL-6R) and skeletal muscle glucose transport. Interleukin-6 has been found to have equivocal effects on glucose transport, with no studies, to our knowledge, investigating any potential role of IL-6R. In the present study, we hypothesized that a combined preparation of IL-6 and soluble IL-6R (sIL-6R) would stimulate glucose transport. Mouse soleus muscles were incubated with physiological and supraphysiological concentrations of IL-6 and a combination of IL-6 and sIL-6R. Total and phosphorylated AMP-activated protein kinase (AMPK) and Protein Kinase B (PKB/Akt) were also measured by Western blotting. Exposure to both physiological (80 pg ml(-1)) and supraphysiological IL-6 (120 ng ml(-1)) had no effect on glucose transport. At physiological levels, exposure to a combination of IL-6 and sIL-6R (32 ng ml(-1)) resulted in a 1.4-fold increase (P < 0.05) in basal glucose transport with no change to the phosphorylation of AMPK. Exposure to supraphysiological levels of IL-6 and sIL-6R (120 ng ml(-1)) resulted in an approximately twofold increase (P < 0.05) in basal glucose transport and an increase (P < 0.05) in AMPK phosphorylation. No effect of IL-6 or sIL-6R was observed on insulin-stimulated glucose transport. These findings demonstrate that, while IL-6 alone does not stimulate glucose transport in mouse soleus muscle, when sIL-6R is introduced glucose transport is directly stimulated, partly through AMPK-dependent signalling.
运动可导致白细胞介素-6（IL-6）、其受体（IL-6R）以及骨骼肌葡萄糖转运增加。白细胞介素-6对葡萄糖转运的影响一直存在争议，据我们所知，尚无研究探讨IL-6R的任何潜在作用。在本研究中，我们假设IL-6与可溶性IL-6R（sIL-6R）的联合制剂会刺激葡萄糖转运。将小鼠比目鱼肌与生理浓度和超生理浓度的IL-6以及IL-6与sIL-6R的组合一起孵育。还通过蛋白质印迹法测量了总AMP激活蛋白激酶（AMPK）和磷酸化AMP激活蛋白激酶以及蛋白激酶B（PKB/Akt）。暴露于生理浓度（80 pg/ml(-1)）和超生理浓度的IL-6（120 ng/ml(-1)）对葡萄糖转运均无影响。在生理水平下，暴露于IL-6与sIL-6R的组合（32 ng/ml(-1)）会导致基础葡萄糖转运增加1.4倍（P<0.05），而AMPK的磷酸化没有变化。暴露于超生理水平的IL-6与sIL-6R（120 ng/ml(-1)）会导致基础葡萄糖转运增加约两倍（P<0.05），并且AMPK磷酸化增加（P<0.05）。未观察到IL-6或sIL-6R对胰岛素刺激的葡萄糖转运有影响。这些发现表明，虽然单独的IL-6不会刺激小鼠比目鱼肌中的葡萄糖转运，但引入sIL-6R后会直接刺激葡萄糖转运，部分是通过AMPK依赖性信号传导实现的。
