Gonadotropin-releasing hormone (GnRH) is the initial central regulator of the animal reproduction system, which is crucial for puberty onset and fertility. However, the mechanisms regulating GnRH production and release remain unclear. In addition, few studies reported that miR-375 expressed in mouse hypothalamus, but up to now there are limited functional studies of miR-375 in regulating GnRH secretion. According to our recent findings that miR-375 was involved in regulating the synthesis and secretion of pituitary hormones, thus, we aimed to identify the role of miR-375 in regulating GnRH production in GT1-7 cells. Immunofluorescence results demonstrated that miR-375 was expressed in all of the GT1-7 cells. The functional studies showed that miR-375 overexpression enhanced GnRH mRNA expression level, but decreased the mRNA expressions of Sp1, Cebpb, Msx1, and Tle4. Transcriptomics analysis demonstrated Sp1 and Tle4 acted as the targeting genes of miR-375, and Sp1 negatively regulated Gnrh mRNA expression by binding to the Gnrh promoter. Thus, we conclude that miR-375 potentially enhances GnRH expression by targeting Sp1 and Tle4 in GT1-7 cells. Our results highlight a critical role of miR-375 in regulating GnRH production, which may provide a novel potential therapeutic approach to neuroendocrine-disorder-related dysfunctions.

促性腺激素释放激素 (GnRH) 是动物生殖系统的初始中枢调节剂，对青春期开始和生育至关重要。然而，调节 GnRH 产生和释放的机制尚不清楚。此外，很少有研究报道miR-375在小鼠下丘脑中表达，但到目前为止，miR-375在调节GnRH分泌方面的功能研究有限。根据我们最近的发现，miR-375 参与调节垂体激素的合成和分泌，因此，我们旨在确定 miR-375 在调节 GT1-7 细胞中 GnRH 产生中的作用。免疫荧光结果表明miR-375在所有 GT1-7 细胞中均有表达。功能研究表明，miR-375过表达增强了 GnRH mRNA 的表达水平，但降低了Sp1、Cebpb、Msx1和Tle4的 mRNA 表达。转录组学分析表明 Sp1 和 Tle4 作为miR-375的靶向基因，Sp1通过与Gnrh启动子结合而负调控Gnrh mRNA 的表达。因此，我们得出结论，miR-375可能通过靶向GT1-7 细胞中的Sp1和Tle4来增强 GnRH 表达。我们的结果突出了miR-375的关键作用 调节 GnRH 的产生，这可能为神经内分泌疾病相关的功能障碍提供一种新的潜在治疗方法。