INRA, UMR1067 Nutrition Métabolisme et Aquaculture, Pôle d'hydrobiologie, CD918, F-64310 St-Pée-sur-Nivelle, France.
Mol Cell Endocrinol. 2012 Apr 4;351(2):220-6. doi: 10.1016/j.mce.2011.12.011. Epub 2011 Dec 22.
The muscle growth in mammals is regulated by several growth factors including myostatin (MSTN), a member of the transforming growth factor-beta (TGF-beta) superfamily. To date, it is unknown in fish whether MSTN could have any effect on proliferation or differentiation of myogenic cells. Using culture of trout satellite cells, we showed that mstn1a and mstn1b mRNA are expressed in myoblasts and that their expression decreased in differentiating myoblasts. We also demonstrated that a treatment with huMSTN decreased the proliferation of IGF1-stimulated myoblasts in a dose-dependent manner. By contrast, treatment of myoblasts with 100 nM of huMSTN for three days, did not affect the percentage of positive cells for myogenin neither the percentage of nuclei in myosin positive cells. Moreover, our results clearly indicated that huMSTN treatment had no effect on MyoD and myogenin protein levels, which suggests that huMSTN did not strongly affect MyoD activity. In conclusion, we showed that huMSTN inhibited proliferation but not differentiation of trout myoblasts, probably resulting from a lack of huMSTN effect on MyoD activity. Altogether, these results show high interspecies differences in the function of MSTN.
哺乳动物的肌肉生长受多种生长因子调节，包括肌肉生长抑制素（MSTN），它是转化生长因子-β（TGF-β）超家族的成员。迄今为止，尚不清楚鱼类中的 MSTN 是否对肌原细胞的增殖或分化有任何影响。通过培养鳟鱼卫星细胞，我们表明 mstn1a 和 mstn1b mRNA 在成肌细胞中表达，并且它们的表达在分化的成肌细胞中减少。我们还证明，huMSTN 处理以剂量依赖性方式降低 IGF1 刺激的成肌细胞的增殖。相比之下，用 100 nM huMSTN 处理成肌细胞三天，既不影响肌球蛋白阳性细胞中肌生成素阳性细胞的百分比，也不影响肌球蛋白阳性细胞核的百分比。此外，我们的结果清楚地表明，huMSTN 处理对 MyoD 和肌生成素蛋白水平没有影响，这表明 huMSTN 对 MyoD 活性没有强烈影响。总之，我们表明 huMSTN 抑制了鳟鱼成肌细胞的增殖但不抑制其分化，这可能是由于 huMSTN 对 MyoD 活性的影响缺乏所致。总之，这些结果表明 MSTN 在不同物种中的功能存在高度的种间差异。
