Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China.
Engineering Laboratory of Animal Pharmaceuticals, College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian Province 350002, PR China.
Res Vet Sci. 2023 Aug;161:132-137. doi: 10.1016/j.rvsc.2023.06.014. Epub 2023 Jun 22.
Testosterone in male mammals is mainly secreted by testicular Leydig cells, and its secretion process is regulated by the hypothalamic-pituitary-gonadal axis. After receiving the luteinizing hormone (LH) stimulus signal, the lutropin/choriogonadotropin receptor (LHCGR) on the Leydig cell membrane transfers the signal into the cell and finally increases the secretion of testosterone by upregulating the expression of steroid hormone synthase. In previous experiments, we found that interfering with the expression of the Luman protein can significantly increase testosterone secretion in MLTC-1 cells. In this experiment, we found that knockdown of Luman in MLTC-1 cells significantly increased the concentration of cAMP and upregulated the expression of AC and LHCGR. Moreover, an analysis of the activity of the LHCGR promoter by a dual luciferase reporter system showed that knockdown of Luman increased the activity of the LHCGR promoter. Therefore, we believe that knockdown of Luman increased the activity of the LHCGR promoter and upregulated the expression of LHCGR, thereby increasing the concentration of intracellular cAMP and ultimately leading to an increase of testosterone secretion by MLTC-1 cells.
雄性哺乳动物的睾酮主要由睾丸间质细胞分泌，其分泌过程受下丘脑-垂体-性腺轴的调节。在接收到黄体生成素（LH）刺激信号后，Leydig 细胞膜上的促黄体激素/绒毛膜促性腺激素受体（LHCGR）将信号转入细胞内，最终通过上调类固醇激素合酶的表达来增加睾酮的分泌。在之前的实验中，我们发现干扰 Luman 蛋白的表达可以显著增加 MLTC-1 细胞中睾酮的分泌。在本实验中，我们发现 MLTC-1 细胞中 Luman 的敲低显著增加了 cAMP 的浓度，并上调了 AC 和 LHCGR 的表达。此外，双荧光素酶报告基因系统分析 LHCGR 启动子的活性表明，Luman 的敲低增加了 LHCGR 启动子的活性。因此，我们认为 Luman 的敲低增加了 LHCGR 启动子的活性，上调了 LHCGR 的表达，从而增加了细胞内 cAMP 的浓度，最终导致 MLTC-1 细胞中睾酮分泌的增加。
