Sertoli cells provide protection and nutrition for developing sperm. Each stage of sperm development occurs on the surface of Sertoli cells. MicroRNA (MiR)-125a-5p is involved in male reproduction. The current research aimed to probe the role of miR-125a-5p in Sertoli cell function. Functionally, miR-125a-5p knockdown facilitated Sertoli cell proliferation, while miR-125a-5p overexpression suppressed Sertoli cell proliferation, as evidenced by 5-ethynyl-20-deoxyuridine incorporation assay. Additionally, miR-125a-5p knockdown inhibited Sertoli cell apoptosis, while miR-125a-5p upregulation facilitated Sertoli cell apoptosis, as evidenced by flow cytometry analysis. Computationally, we identified four predicted mRNA targets of miR-125a-5p. Based on the results of luciferase reporter assay, miR-125a-5p was confirmed to bind to the predicted sequence in the Ras-related protein Rab-3D (RAB3D) 3’UTR. Rescue experiments showed that miR-125a-5p suppressed the proliferative ability of TM4 Sertoli cells and facilitated their apoptosis by targeting RAB3D. Finally, our data confirmed that miR-125a-5p and RAB3D modulated activation of the PI3K/AKT pathway. In conclusion, our data showed that miR-125a-5p regulated Sertoli cell proliferation and apoptosis by targeting RAB3D and regulating the PI3K/AKT pathway.

中文翻译：

---

MicroRNA-125a-5p 通过靶向 RAB3D 和调节 PI3K/AKT 信号通路调节 TM4 Sertoli 细胞的增殖和凋亡

支持细胞为发育精子提供保护和营养。精子发育的每个阶段都发生在支持细胞的表面。MicroRNA (MiR)-125a-5p 参与雄性繁殖。目前的研究旨在探讨 miR-125a-5p 在支持细胞功能中的作用。在功能上，miR-125a-5p 敲低促进支持细胞增殖，而 miR-125a-5p 过表达抑制支持细胞增殖，5-乙炔基-20-脱氧尿苷掺入试验证明了这一点。此外，miR-125a-5p 敲低抑制支持细胞凋亡，而 miR-125a-5p 上调促进支持细胞凋亡，流式细胞术分析证明。在计算上，我们确定了 miR-125a-5p 的四个预测 mRNA 靶标。基于荧光素酶报告基因检测的结果，证实 miR-125a-5p 与 Ras 相关蛋白 Rab-3D (RAB3D) 3'UTR 中的预测序列结合。救援实验表明，miR-125a-5p 通过靶向 RAB3D 抑制 TM4 Sertoli 细胞的增殖能力并促进其凋亡。最后，我们的数据证实 miR-125a-5p 和 RAB3D 调节 PI3K/AKT 通路的激活。总之，我们的数据显示 miR-125a-5p 通过靶向 RAB3D 和调节 PI3K/AKT 通路来调节支持细胞的增殖和凋亡。