Department of Physiology, Graduate School of Health Sciences, Toyohashi SOZO University, Aichi, Japan.
PLoS One. 2013 Dec 6;8(12):e81929. doi: 10.1371/journal.pone.0081929. eCollection 2013.
The purpose of this study was to investigate the expression level of adiponectin and its related molecules in hypertrophied and atrophied skeletal muscle in mice. The expression was also evaluated in C2C12 myoblasts and myotubes. Both mRNA and protein expression of adiponectin, mRNA expression of adiponectin receptor (AdipoR) 1 and AdipoR2, and protein expression of adaptor protein containing pleckstrin homology domain, phosphotyrosine binding domain, and leucine zipper motif 1 (APPL1) were observed in C2C12 myoblasts. The expression levels of these molecules in myotubes were higher than those in myoblasts. The expression of adiponectin-related molecules in soleus muscle was observed at mRNA (adiponectin, AdipoR1, AdipoR2) and protein (adiponectin, APPL1) levels. The protein expression levels of adiponectin and APPL1 were up-regulated by 3 weeks of functional overloading. Down-regulation of AdipoR1 mRNA, but not AdipoR2 mRNA, was observed in atrophied soleus muscle. The expression of adiponectin protein, AdipoR1 mRNA, and APPL1 protein was up-regulated during regrowth of unloading-associated atrophied soleus muscle. Mechanical loading, which could increase skeletal muscle mass, might be a useful stimulus for the up-regulations of adiponectin and its related molecules in skeletal muscle.
本研究旨在探讨肥胖和萎缩骨骼肌中脂联素及其相关分子的表达水平。还评估了 C2C12 成肌细胞和肌管中的表达情况。在 C2C12 成肌细胞中观察到脂联素、脂联素受体（AdipoR）1 和 AdipoR2 的 mRNA 表达以及含 PH 结构域、磷酸酪氨酸结合域和亮氨酸拉链基序 1（APPL1）的衔接蛋白的蛋白表达。这些分子在肌管中的表达水平高于成肌细胞。在比目鱼肌中观察到脂联素相关分子在 mRNA（脂联素、AdipoR1、AdipoR2）和蛋白质（脂联素、APPL1）水平上的表达。3 周的功能性超负荷导致脂联素和 APPL1 的蛋白表达上调。萎缩的比目鱼肌中 AdipoR1mRNA 下调，但 AdipoR2mRNA 未下调。去负荷相关萎缩比目鱼肌中脂联素蛋白、AdipoR1mRNA 和 APPL1 蛋白的表达上调。机械负荷可增加骨骼肌质量，可能是上调骨骼肌中脂联素及其相关分子的有效刺激。
