Wang Xiaorong, Zhang Xiansheng, Wang Guishuan, Wang Lu, Lin Yu, Sun Fei
Department of Cell and Developmental Biology, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
Department of Urology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230032, China.
Gene. 2017 Aug 30;626:344-353. doi: 10.1016/j.gene.2017.05.033. Epub 2017 May 13.
Previous studies have reported the miR-513b is located on the X chromosome and is preferentially expressed in testis. However, the underlying mechanisms of miR-513b involved in spermatogenesis remains unknown. In this study, we found that hsa-miR-513b-5p was highly expressed in the testes of infertile males with maturation arrest compared with normal controls. Overexpression of hsa-miR-513b-5p suppressed testicular embryonal carcinoma (NT2) cell proliferation and induced apoptosis in vitro, whereas silencing of hsa-miR-513b-5p reversed these effects. In addition, we found that interferon regulatory transcription factor 2 (IRF2) was a direct and functional target of hsa-miR-513b-5p. Silencing of endogenous IRF2 enhanced hsa-miR-513b-5p-mediated effects on cell proliferation in NT2 cells, whereas overexpression of IRF2 reversed these effects. Moreover, immunoblotting showed that overexpression of hsa-miR-513b-5p or silencing of endogenous IRF2 could promote the expression of P53. Moreover, overexpression of hsa-miR-513b-5p in the absence of p53 could also induce cell apoptosis. Together, our results suggest that hsa-miR-513b-5p suppresses NT2 cell proliferation and promotes P53 protein expression by targeting IRF2, and abnormal testicular hsa-miR-513b-5p expression may contribute to maturation arrest.
先前的研究报道miR-513b位于X染色体上，且在睾丸中优先表达。然而，miR-513b参与精子发生的潜在机制仍不清楚。在本研究中，我们发现与正常对照相比，hsa-miR-513b-5p在成熟停滞的不育男性睾丸中高表达。hsa-miR-513b-5p的过表达在体外抑制睾丸胚胎癌（NT2）细胞增殖并诱导细胞凋亡，而hsa-miR-513b-5p的沉默则逆转了这些作用。此外，我们发现干扰素调节转录因子2（IRF2）是hsa-miR-513b-5p的直接功能靶点。内源性IRF2的沉默增强了hsa-miR-513b-5p对NT2细胞增殖的介导作用，而IRF2的过表达则逆转了这些作用。此外，免疫印迹显示hsa-miR-513b-5p的过表达或内源性IRF2的沉默可促进P53的表达。此外，在没有p53的情况下hsa-miR-513b-5p的过表达也可诱导细胞凋亡。总之，我们的结果表明，hsa-miR-513b-5p通过靶向IRF2抑制NT2细胞增殖并促进P53蛋白表达，睾丸中hsa-miR-513b-5p的异常表达可能导致成熟停滞。
