College of Veterinary Medicine, Shaanxi Centre of Stem Cells Engineering and Technology, Northwest A&F University, Yangling, Shaanxi, China.
Faculty of Science, Laboratoire des sciences Agronomiques et Biologiques pour le Développement (LASBAD), University of Bangui, Central Africa.
J Cell Physiol. 2018 Jun;233(6):4652-4665. doi: 10.1002/jcp.26231. Epub 2017 Nov 24.
Promyelocytic leukemia zinc finger PLZF, known as ZBTB16 or ZFP145 is a critical zinc finger protein of male germline stem cells (mGSCs), it's an essential transcriptional factor for goat testis development and spermatogenesis. Loss of PLZF results in progressive depletion of SSCs after the first wave of spermatogenesis leading to eventual spermatogenic arrest, apparently the result of a shift in the balance in SSC fate away from self-renewal and toward differentiation. Cumulating evidences have demonstrated that microRNAs are expressed in a cell-specific or stage-specific manner during spermatogenesis and acts as regulators on specific makers such as Stra8, ETV5, and PLZF. However, the post transcriptional function of PLZF still poorly elucidate in mGSCs. Bioinformatic analysis and dual luciferase reporter assay showed that miR-19b-3p binds the 3'UTR of PLZF, suggesting that PLZF is a direct target of miR-19b-3p. The profile of miR-19b-3p and PLZF analyzed in dairy goat testis at different age showed that miR-19b-3p was significantly up-regulated in goat testis at 1, 3, 6 months and downregulated at 12, 18, and 24 months which was inversely correlated with PLZF in the same testis. Focusing on the role of miR-19b-3p, we found that miR-19b-3p changes c-KIT and mTOR signaling through PLZF to promote proliferation in goat nGSCs and infertile mice testes. Over-expression of PLZF significantly reversed miR-19b-3p-mediated proliferation in mice testes. We found also that miR-19b-3p reduced heterochromatin-mediated senescence through PLZF localized on HP1α. Taken together, our findings indicate that miR-19b-3p promotes proliferation and reduces heterochromatin-mediated senescence through PLZF in mGSCs.
早幼粒细胞白血病锌指蛋白 PLZF，也称为 ZBTB16 或 ZFP145，是精原干细胞 (mGSCs) 的关键锌指蛋白，它是山羊睾丸发育和精子发生所必需的转录因子。PLZF 的缺失导致第一次精子发生后 SSCs 的逐渐耗竭，最终导致精子发生停滞，显然是 SSC 命运平衡从自我更新向分化转移的结果。越来越多的证据表明，miRNAs 在精子发生过程中以细胞特异性或阶段特异性的方式表达，并作为 Stra8、ETV5 和 PLZF 等特定标记物的调节剂。然而，PLZF 在 mGSCs 中的转录后功能仍未得到充分阐明。生物信息学分析和双荧光素酶报告基因检测显示，miR-19b-3p 结合 PLZF 的 3'UTR，表明 PLZF 是 miR-19b-3p 的直接靶标。在不同年龄的奶山羊睾丸中分析 miR-19b-3p 和 PLZF 的特征表明，miR-19b-3p 在 1、3、6 个月的山羊睾丸中显著上调，而在 12、18 和 24 个月的山羊睾丸中下调，与同一睾丸中的 PLZF 呈负相关。研究 miR-19b-3p 的作用时，我们发现 miR-19b-3p 通过 PLZF 改变 c-KIT 和 mTOR 信号通路，促进山羊 nGSCs 和不育小鼠睾丸的增殖。过表达 PLZF 可显著逆转 miR-19b-3p 在小鼠睾丸中的增殖作用。我们还发现，miR-19b-3p 通过位于 HP1α 上的 PLZF 减少异染色质介导的衰老。总之，我们的研究结果表明，miR-19b-3p 通过 PLZF 在 mGSCs 中促进增殖并减少异染色质介导的衰老。
