College of Animal Science and Technology, Sichuan Agricultural University, Chengdu 611130, China.
Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, China.
Genes (Basel). 2020 Mar 29;11(4):369. doi: 10.3390/genes11040369.
Noncoding RNAs, especially microRNAs (miRNAs), have been reported to play important roles during skeletal muscle development and regeneration. Our previous sequencing data revealed that miR-99a-5p is one of the most abundant miRNAs in chicken breast muscle. The purpose of this study was to reveal the regulatory mechanism of miR-99a-5p in the proliferation and differentiation of chicken skeletal muscle satellite cells (SMSCs). Through the investigation of cell proliferation activity, cell cycle progression, and 5-ethynyl-29-deoxyuridine (EdU) assay, we found that miR-99a-5p can significantly promote the proliferation of SMSCs. Moreover, we found that miR-99a-5p can inhibit myotube formation by decreasing the expression of muscle cell differentiation marker genes. After miR-99a-5p target gene scanning, we confirmed that miR-99a-5p directly targets the 3' untranslated region (UTR) of myotubularin-related protein 3 (MTMR3) and regulates its expression level during chicken SMSC proliferation and differentiation. We also explored the role of MTMR3 in muscle development and found that its knockdown significantly facilitates the proliferation but represses the differentiation of SMSCs, which is opposite to the effects of miR-99a-5p. Overall, we demonstrated that miR-99a-5p regulates the proliferation and differentiation of SMSCs by targeting MTMR3.
非编码 RNA，尤其是 microRNAs（miRNAs），在骨骼肌发育和再生过程中发挥着重要作用。我们之前的测序数据显示，miR-99a-5p 是鸡胸肌中最丰富的 miRNA 之一。本研究旨在揭示 miR-99a-5p 在鸡骨骼肌卫星细胞（SMSCs）增殖和分化中的调控机制。通过研究细胞增殖活性、细胞周期进程和 5-乙炔基-29-脱氧尿苷（EdU）检测，我们发现 miR-99a-5p 可显著促进 SMSCs 的增殖。此外，我们发现 miR-99a-5p 通过降低肌肉细胞分化标记基因的表达来抑制肌管形成。在 miR-99a-5p 靶基因扫描后，我们证实 miR-99a-5p 可直接靶向肌小管相关蛋白 3（MTMR3）的 3'非翻译区（UTR），并在鸡 SMSC 增殖和分化过程中调节其表达水平。我们还探索了 MTMR3 在肌肉发育中的作用，发现其敲低显著促进 SMSCs 的增殖，但抑制其分化，这与 miR-99a-5p 的作用相反。总体而言，我们证明 miR-99a-5p 通过靶向 MTMR3 来调节 SMSCs 的增殖和分化。
