Wang Pengchao, Zhao Yuanyuan, Fan Ruiwen, Chen Tianzhi, Dong Changsheng
College of Animal Science and Technology, Shanxi Agricultural University, Taigu 030801, Shanxi, China.
Wujiang River Institute of Agriculture & Forestry Economics, Tongren University, Tongren 554300, Guizhou, China.
Int J Mol Sci. 2016 Jun 24;17(7):959. doi: 10.3390/ijms17070959.
MicroRNAs (miRNAs) play an important role in regulating almost all biological processes. miRNAs bind to the 3' untranslated region (UTR) of mRNAs by sequence matching. In a previous study, we demonstrated that miR-21 was differently expressed in alpaca skin with different hair color. However, the molecular and cellular mechanisms for miR-21 to regulate the coat color are not yet completely understood. In this study, we transfected miR-21a-5p into mouse melanocytes and demonstrated its function on melanogenesis of miR-21a-5p by targeting Sox5, which inhibits melanogenesis in mouse melanocytes. The results suggested that miR-21a-5p targeted Sox5 gene based on the binding site in 3' UTR of Sox5 and overexpression of miR-21a-5p significantly down-regulated Sox5 mRNA and protein expression. Meanwhile, mRNA and protein expression of microphthalmia transcription factor (MITF) and Tyrosinase (TYR) were up-regulated, which subsequently make the melanin production in melanocytes increased. The results suggest that miR-21a-5p regulates melanogenesis via MITF by targeting Sox5.
微小RNA（miRNA）在调控几乎所有生物过程中发挥着重要作用。miRNA通过序列匹配与mRNA的3'非翻译区（UTR）结合。在先前的一项研究中，我们证明了miR-21在不同毛色的羊驼皮肤中表达存在差异。然而，miR-21调控毛色的分子和细胞机制尚未完全明确。在本研究中，我们将miR-21a-5p转染至小鼠黑素细胞中，并通过靶向抑制小鼠黑素细胞黑素生成的Sox5来证明其对miR-21a-5p黑素生成的作用。结果表明，基于Sox5的3'UTR中的结合位点，miR-21a-5p靶向Sox5基因，miR-21a-5p的过表达显著下调了Sox5的mRNA和蛋白表达。同时，小眼畸形相关转录因子（MITF）和酪氨酸酶（TYR）的mRNA和蛋白表达上调，随后使黑素细胞中的黑色素生成增加。结果表明，miR-21a-5p通过靶向Sox5经由MITF调控黑素生成。
