自噬介导的生精微环境异常在DEHP致雄性生殖功能发育障碍中的机制研究

Male reproductive dysfunction is a global problem and the decreasing semen quality is the main reason. The impairment of testicular microenvironment lead to the dysfunction of spermatocyte and spermatogenesis, which will contribute to male infertility. Our previous study found that DEHP as the most important environmental endocrine disruptors, caused immature testicular abnormalities closely associated with oxidative stress, and abnormal autophagy signaling pathway involved in, but the exact mechanism is unknown. The project intends to go down with this idea "DEHP exposure-oxidative stress -impaired mTOR- autophagy- abnormality- testicular micro-environmental imbalance- male reproductive function developmental disorders ", in-depth study in ROS as initiating factor in affecting the mTOR system, the regulation of the activity of the autophagy signaling pathway, consequently casing obstacles to the proliferation and differentiation of spermatogonial stem cells, leading to male reproductive dysfunction. It clarifies the molecular mechanisms of DEHP as the cause of male reproductive dysfunction from the source. And it aims at the point that oxidative stress injury is the initiating factor and the key point of DEHP causing male reproductive dysfunction, investigating the effects of vitamin E and vitamin C in the prevention and treatment as well as potential applications of intervening DEHP-induced testicular impairment and reproductive toxicity. The results are bound to provide scientific experimental basis in developing environmental policy for the government, handling pollution, clinical prevention and intervening spermatogenesis dysfunction.

男性生殖功能障碍是威胁人类生殖健康的全球性难题，精液质量降低是主要原因。生精微环境的破坏将直接导致生精细胞发育障碍，进而减少精子生成并造成男性不育。课题组前期研究发现白色污染源DEHP作为最主要的环境内分泌干扰物，所致未成熟睾丸发育异常与氧化应激损伤密切相关，且涉及自噬通路异常，但具体机制不详。本项目拟沿着“DEHP暴露—氧化应激损伤—mTOR表达失衡—自噬通路异常—生精微环境破坏—生殖功能发育障碍”深入研究ROS作为始动因素如何影响mTOR表达，调控自噬，干扰生精微环境，引起生精细胞异常并导致雄性生殖功能发育障碍。从源头上阐明DEHP致雄性生殖功能障碍的分子机制。针对ROS损伤是DEHP导致睾丸发育异常的关键环节，探讨维生素E和C联合作用在干预DEHP所致睾丸发育和生殖毒性中的防治作用及潜在的应用价值。研究结果必将为政府制定环保政策、治理污染和临床预防、干预生殖功能障碍提供科学实验依据。

隐睾、小睾丸等睾丸发育异常是小儿时期最常见的泌尿生殖畸形，严重影响患儿成年后的生殖功能，关系着人类的生存与繁衍。作为使用最广泛的邻苯二甲酸酯衍生物，邻苯二甲酸二-(2-乙基己基)酯 (DEHP) 会导致生殖障碍，尤其是男性。当睾丸在未成熟阶段暴露于DEHP时，可能会引发睾丸损伤。然而，潜在的机制仍不清楚。在本研究中，从出生后第20天到第30天，SD大鼠暴露于0、250和500mg/kg/d的DEHP；精原细胞系GC-1和精母细胞系GC-2暴露于不同剂量的MEHP。研究结果表明，DEHP暴露后，睾丸结构受损，精子发生过程受到干扰，氧化应激水平增加。在精原细胞系和精母细胞系中，自噬相关蛋白的表达显著下调，导致细胞焦亡途径的激活，精原细胞自我更新和分化的失衡，导致生殖细胞发育停滞。综上所述，DEHP暴露导致氧化应激增加，NLRP3炎性小体激活，诱发细胞焦亡，为DEHP致未成熟睾丸发育损伤提供了新的见解。研究结果为政府制定环保政策、治理污染和临床预防、干预生殖畸形的发生及功能障碍提供科学的实验依据。