Takahashi H, Sato K, Yamaguchi T, Miyake M, Watanabe H, Nagasawa Y, Kitagawa E, Terada S, Urakawa M, Rose M T, McMahon C D, Watanabe K, Ohwada S, Gotoh T, Aso H
Cellular Biology Laboratory, Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai-shi, Japan; Faculty of Agriculture, Graduate school, Kuju Agricultural Research Center, Kyushu University, Kuju-cho, Taketa-shi, Japan.
Cellular Biology Laboratory, Graduate School of Agricultural Science, Tohoku University, Aoba-ku, Sendai-shi, Japan.
Domest Anim Endocrinol. 2014 Jul;48:62-8. doi: 10.1016/j.domaniend.2014.01.007. Epub 2014 Feb 10.
The purpose of this study was to determine whether myostatin alters glucose transporter-4 (GLUT4) expression in bovine skeletal muscles and myoblasts isolated from double-muscled (DM) and normal-muscled (NM) Japanese Shorthorn cattle. Plasma concentrations of glucose were lower in DM cattle than in NM cattle (P < 0.01). The expression of GLUT4 messenger RNA (mRNA) in the skeletal muscle ex vivo and in myoblasts at 72 h after differentiation in vitro was higher in DM cattle than in NM cattle (P < 0.01). In contrast, the NM and DM cattle did not differ with respect to skeletal muscle expression of GLUT1 and myocyte enhancer factor-2c (MEF2c), a transcription factor of GLUT4. In differentiated myoblasts, the expression of GLUT1, GLUT4, and MEF2c mRNAs was greater in DM cattle than in NM cattle (P < 0.01). In the presence and absence of insulin, glucose uptake in myoblasts was increased in DM cattle relative to that of NM cattle (P < 0.01). The addition of myostatin decreased the expression of GLUT4 and MEF2c mRNAs in DM myoblasts (P < 0.05). Results of the present study suggest that myostatin inhibits the expression of GLUT4 mRNA possibly via MEF2c and that the greater ability of the DM cattle to produce muscle relative to the NM cattle may be due to their greater sensitivity to insulin and greater use of glucose.
本研究的目的是确定肌肉生长抑制素是否会改变从双肌（DM）和正常肌肉（NM）日本短角牛分离出的牛骨骼肌和肌细胞中葡萄糖转运蛋白4（GLUT4）的表达。DM牛的血浆葡萄糖浓度低于NM牛（P < 0.01）。DM牛体外骨骼肌和体外分化72小时后肌细胞中GLUT4信使核糖核酸（mRNA）的表达高于NM牛（P < 0.01）。相反，NM牛和DM牛在GLUT1和GLUT4的转录因子肌细胞增强因子2c（MEF2c）的骨骼肌表达方面没有差异。在分化的肌细胞中，DM牛的GLUT1、GLUT4和MEF2c mRNA的表达高于NM牛（P < 0.01）。在有胰岛素和无胰岛素的情况下，DM牛肌细胞中的葡萄糖摄取相对于NM牛增加（P < 0.01）。添加肌肉生长抑制素会降低DM肌细胞中GLUT4和MEF2c mRNA的表达（P < 0.05）。本研究结果表明，肌肉生长抑制素可能通过MEF2c抑制GLUT4 mRNA的表达，并且DM牛相对于NM牛更大的肌肉生成能力可能是由于它们对胰岛素的更高敏感性和对葡萄糖的更多利用。
