探索瘦素对睾丸生精功能的影响及机制研究

Male infertility has a great adverse effect on human reproductive health. Whereas, for the most male infertility patients with spermatogenic dysfunction, it is difficult to identify its causes and the specific mechanisms. In order to safeguard and promote male reproductive health, it has great importance to further study the mechanism of spermatogenesis.Currently, the recent studies have found that the abnormal expression of Leptin is closely related to the spermatogenic dysfunction, however, its regulation is not clear. Our previous studies have found that the testicular spermatogenesis of infertile varicocele patients and animal models of varicocele is impaired, while the expression of Leptin and its receptor are increased, which indicate that Leptin plays an important roles for the regulation of testicular germ cells and testicular micro-environment. Therefore, in order to identify the impact of leptin on spermatogenesis, we will construct different animal models in this project , whose Leptin expression level in testis is up or down. We intend to study the impact of Leptin on spermatogenesis in two regards, including testicular micro-environment and spermatogenic function. Firstly, we will observe the position and quantitative situation of the Leptin on testicular tissue pathology.Then we will further study the changes of the testicular spermatogenic function and micro-environment. In addition, we will not only detect the apoptosis, proliferation and differentiation of germ cells but check the apoptosis-related factors and gene expression.Secondly, to clear the function of Leptin on testicular micro-environment, we will cultivate Leydig cells, Sertoli cells and spermatogonia in 3-dimensional culture. Subsequently, vitro intervened by Leptin, we will detect the changes in testicular micro-environment. Our project intends to study the impact of Leptin to Leydig cells, Sertoli cells and spermatogenic cells on function, proliferation, differentiation and apoptosis. For the purpose of identifying whether Letpin is one of the regulatory factors to increase cell apoptosis and through which apoptotic pathway,we will make antagonistic biological effects through different signaling pathway inhibitors, in order to clear the specific regulation and signaling pathways of leptin.Thirdly, we will observe the expression of leptin on the testis of male infertility patients with spermatogenic dysfunction, detect the apoptosis, proliferation and differentiation of germ cells and check the apoptosis-related factors and gene expression.In conclusion, from upper studies, our project will reveal the repercussion of Leptin on spermatogenesis for the sake of providing a potential new target for the treatment to the male infertility patients with spermatogenic dysfunction.

男性不育症是影响人类生殖健康的重大问题，其中相当一部分患者存在生精功能障碍，深入研究影响睾丸生精功能的原因和机制对于诊断与治疗男性不育症具有重要意义。我们前期工作发现睾丸瘦素表达异常与生精功能障碍密切相关，但其具体机制尚未明确。本项目通过构建体内瘦素表达上调及下调不同动物模型，观察瘦素在睾丸组织表达情况，睾丸生精功能，微环境变化，细胞凋亡、增殖及分化情况，凋亡相关因子及基因表达变化情况，明确瘦素对于睾丸生精功能的影响。其次，通过细胞水平研究瘦素对睾丸间质细胞、支持细胞及生精细胞的功能、增殖、分化及凋亡的影响，并通过不同信号通路抑制剂拮抗生物学效应，明确其具体调控机制及信号通路。最后，通过人体水平观察瘦素在生精功能障碍男性不育患者表达情况，生殖细胞凋亡、增殖及分化情况，以及凋亡相关因子及基因表达变化情况，从而阐明瘦素对于人类睾丸生精功能的影响，为治疗生精功能障碍男性不育患者提供潜在的新靶点。

瘦素（Leptin）与睾丸生精功能密切相关。本项目是基于前期研究中发现Leptin与男性不育相关联的基础上，进行深入的机制探讨。在精索静脉曲张动物模型和人体水平中均发现精索静脉曲张影响生育力与睾丸组织及精浆中的Leptin水平有关。在高脂饮食构建瘦素高表达大鼠模型中，Leptin表达水平影响睾丸的生精功能。研究中成功分离睾丸间质细胞、支持细胞以及生精细胞，Leptin可能通过JAK/ STAT-3、MAPK/ ERK1/2 以及PI3K/ Akt 信号通路影响间质细胞和支持细胞，Leptin还可通过AKT、ERK及M-TOR影响生精细胞，导致生精细胞凋亡。临床发现睾丸功能下降或男性不育患者血清及精浆lepting水平下降。Leptin定位于人体睾丸生精细胞和间质细胞，睾丸功能下降患者睾丸组织中leptin表达明显低于生精功能正常患者。这些研究结果将为男性不育患者提供临床诊断标志物和治疗生精功能障碍男性不育患者提供潜在新靶点。