Luo Hui, Peng Fuzhi, Weng Bo, Tang Xiangwei, Chen Yao, Yang Anqi, Chen Bin, Ran Maoliang
College of Animal Science and Technology, Hunan Provincial Key Laboratory for Genetic Improvement of Domestic Animal, Hunan Agricultural University, Changsha, China.
Front Genet. 2020 Oct 29;11:581593. doi: 10.3389/fgene.2020.581593. eCollection 2020.
Sertoli cells are central and essential coordinators of spermatogenesis. Accumulating evidence has demonstrated that miRNAs participate in the regulation of Sertoli cell growth. However, the functions and the regulatory mechanisms of miRNAs in Sertoli cells of domestic animals remain largely unknown. Here we report that miR-222 overexpression repressed cell cycle progression and proliferation and promoted the apoptosis of immature porcine Sertoli cells, whereas miR-222 inhibition resulted in the opposite result. miR-222 directly targeted the 3'-UTR of the gene and inhibited its mRNA abundance. An siRNA-induced knockdown showed similar effects as did miR-222 overexpression on cell proliferation and apoptosis and further attenuated the role of miR-222 inhibition. Furthermore, both miR-222 overexpression and inhibition repressed the phosphorylation of PI3K and AKT, the key elements of the PI3K/AKT signaling pathway, whereas inhibition offsets the effects of the miR-222 knockdown. Overall, we concluded that miR-222 suppresses immature porcine Sertoli cell growth by targeting the gene through inactivation of the PI3K/AKT signaling pathway. This study provides novel insights into the epigenetic regulation of porcine spermatogenesis by determining the fate of Sertoli cells.
支持细胞是精子发生的核心且必不可少的协调者。越来越多的证据表明，微小RNA（miRNA）参与支持细胞生长的调控。然而，miRNA在家畜支持细胞中的功能和调控机制仍 largely unknown。在此我们报告，miR-222过表达抑制未成熟猪支持细胞的细胞周期进程和增殖，并促进其凋亡，而抑制miR-222则产生相反的结果。miR-222直接靶向该基因的3'-非翻译区（3'-UTR）并抑制其mRNA丰度。小干扰RNA（siRNA）诱导的该基因敲低对细胞增殖和凋亡产生的影响与miR-222过表达相似，并进一步减弱了抑制miR-222的作用。此外，miR-222过表达和该基因抑制均抑制PI3K/AKT信号通路的关键元件PI3K和AKT的磷酸化，而该基因抑制抵消了miR-222敲低的影响。总体而言，我们得出结论，miR-222通过使PI3K/AKT信号通路失活，靶向该基因来抑制未成熟猪支持细胞的生长。这项研究通过确定支持细胞的命运，为猪精子发生的表观遗传调控提供了新的见解。
