Recombinant myostatin reduces highly expressed microRNAs in differentiating C2C12 cells.
Recombinant myostatin reduces highly expressed microRNAs in differentiating C2C12 cells.
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DOI：
10.1016/j.bbrep.2017.01.003
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发表时间：
2017-03
影响因子：
2.7
通讯作者：
Cardozo CP
中科院分区：
文献类型：
--
作者：
Graham ZA;De Gasperi R;Bauman WA;Cardozo CP
肌生长抑制素是由骨骼肌产生和分泌的小糖肽。它是一种有效的肌肉生长的负调节因子，与虚弱的状况有关。在C2C12细胞中，肌生成抑制素限制细胞分化。肌生长抑制素通过激活素受体IIB、激活素受体样激酶（activin receptor-like kinase， ALK）和Smad转录因子起作用。microRNAs （miRNA）是一种短的22个碱基对核苷酸，与目标mRNA的3 ' UTR结合，抑制翻译或降低mRNA的稳定性。在本研究中，在诱导分化后1天，用1µg重组肌生长抑制素处理后，myomiRs miR-1和133a在分化的C2C12细胞中的表达下调，而所有myomiRs （miR-1、133a/b和206）在1天被SB431542上调，SB431542是一种有效的ALK4/5/7抑制剂，可以减少Smad2信号，除miR-206外。在第3天，SB431542上调了miR-486的表达。用SB431542治疗后，肌肉富集的miR-486的表达更大，但未被肌肉生长抑制素改变。骨骼肌中其他高表达的mirna， miR-23a/b和145，仅在诱导分化后1天发生改变。miR-27b在第1天对治疗的反应不同，在第1天，miR-27b上调，而在第3天，miR-27b下调。肌生成抑制素和SB431542都没有改变细胞大小或细胞形态。数据表明，肌生长抑制素抑制分化C2C12细胞中myomiR的表达，SB431542抑制Smad信号传导可导致分化成肌细胞中高表达mirna的大量变化。肌生长抑制素在肌管形成之前和过程中下调成肌细胞的myomir。抑制ALK信号会增加成肌细胞中高表达miRNA的表达。肌生长抑制素和ALK抑制对诱导分化后1 D的miRNA谱有较大影响。
Myostatin is small glycopeptide that is produced and secreted by skeletal muscle. It is a potent negative regulator of muscle growth that has been associated with conditions of frailty. In C2C12 cells, myostatin limits cell differentiation. Myostatin acts through activin receptor IIB, activin receptor-like kinase (ALK) and Smad transcription factors. microRNAs (miRNA) are short, 22 base pair nucleotides that bind to the 3′ UTR of target mRNA to repress translation or reduce mRNA stability. In the present study, expression in differentiating C2C12 cells of the myomiRs miR-1 and 133a were down-regulated following treatment with 1 µg of recombinant myostatin at 1 d post-induction of differentiation while all myomiRs (miR-1, 133a/b and 206) were upregulated by SB431542, a potent ALK4/5/7 inhibitor which reduces Smad2 signaling, at 1 d and all, with the exception of miR-206, were upregulated by SB431542 at 3 d. The expression of the muscle-enriched miR-486 was greater following treatment with SB431542 but not altered by myostatin. Other highly expressed miRNAs in skeletal muscle, miR-23a/b and 145, were altered only at 1 d post-induction of differentiation. miR-27b responded differently to treatments at 1 d, where it was upregulated, as compared to 3 d, where it was downregulated. Neither myostatin nor SB431542 altered cell size or cell morphology. The data indicate that myostatin represses myomiR expression in differentiating C2C12 cells and that inhibition of Smad signaling with SB431542 can result in large changes in highly expressed miRNAs in differentiating myoblasts. Myostatin down-regulates the myomiRs in myoblasts prior to and during myotube formation. Inhibition of ALK signaling increases expression of highly-expressed miRNA in myoblasts. Myostatin and ALK inhibition has a greater effect on the miRNA profile at 1 D post-induction of differentiation.