高尿酸导致男性睾酮水平低下的分子机制研究

Hyperuricemia is an important risk factor of hypotestosterone, which affects male reproductive health seriously. But its molecular mechanisms is not clear. In our previous study, we found that hyperuricemia can cause hypotestosterone in male and male mice, resulting in destruction of testicular structure, reduced sperm quality, decreased fertility and increased expression of GRP78 and LC3-Ⅱ in testis tissue. We speculated that hyperuricemia may cause hypotestosterone by activating ER stress and ER-phagy, and injure the Leydig cells of the testis, resulting in low testosterone levels. In this study, we intend to clarify the mechanism of endoplasmic reticulum stress and endoplasmic reticulum autophagy induced by hyperuricemia in mouse Leydig cell, by using laser scanning confocal microscopy, transmission electron microscopy, Western blot, qRT-PCR and immunohistochemistry in the mouse model of hyperuricemia and mouse Leydig cell line TM3 cells. To study the testosterone secretion ability of TM3 cells and the changes of testosterone level, fertility and sperm quality of high uric acid mice, we intend to block the endoplasmic reticulum stress and endoplasmic reticulum autophagy at the cellular level and overall level. This project will reveal the mechanism of hypotestosterone resulting from hyperuricemia. This study will provide a basis for the early prevention and treatment of hyperuricemia and male hypotestosterone, which is of great significance for male reproductive health.

高尿酸血症是导致男性睾酮水平低下的重要危险因素，严重影响男性生殖健康，但机制不清。课题组前期发现，高尿酸可导致男性及雄性小鼠睾酮水平低下，引起小鼠睾丸结构破坏、精子质量明显降低、生育能力显著减退、睾丸组织内质网应激标志蛋白GRP78及自噬特异蛋白LC3-Ⅱ表达显著升高、自噬小体增多。推测高尿酸可能通过激活内质网应激及内质网自噬，损伤睾丸间质细胞，导致睾酮水平低下。本课题拟应用自发高尿酸血症小鼠及小鼠睾丸间质细胞系TM3细胞，通过激光共聚焦成像、透射电镜、Western blot、qRT-PCR、免疫组化等技术，明确高尿酸是否通过调控内质网应激及内质网自噬参与睾丸间质细胞损伤；在细胞和整体水平抑制内质网应激及内质网自噬，验证其在高尿酸影响睾丸间质细胞功能及小鼠生殖能力中的作用，最终揭示高尿酸导致睾酮水平低下的分子机制。本课题将为男性睾酮水平低下的早期防治提供依据，对男性生殖健康具有重要意义。

高尿酸血症是导致男性睾酮水平低下的重要危险因素，严重影响男性生殖健康，但机制不清。课题组前期发现，高尿酸可导致男性人群及雄性小鼠睾酮水平低下，引起小鼠睾丸结构破坏、精子质量明显降低、生育能力显著减退、睾丸组织内质网应激标志蛋白GRP78及自噬特异蛋白LC3-Ⅱ表达显著升高、自噬小体增多。推测高尿酸可能通过激活内质网应激及内质网自噬，损伤睾丸间质细胞，导致睾酮水平低下。课题组发现高尿酸处理小鼠睾丸间质细胞系TM3细胞后，细胞培养液中睾酮的浓度显著降低，细胞p-PERK、Nrf2及ATF4的表达明显增加，给予ER Stress抑制剂及PERK抑制剂预处理，可降低上述变化的幅度；发现尿酸氧化酶敲除小鼠睾丸组织中p-PERK、Nrf2及ATF4的表达明显增加，明确了高尿酸可通过PERK/Nrf2/ATF4信号通路参与睾丸间质细胞损伤，导致睾酮水平低下。本课题为男性睾酮水平低下的早期防治提供依据，对男性生殖健康具有重要意义。