Parthanatos死亡通路抑制分子Iduna在睾丸辐射损伤中的作用研究

Spermatogonium damage is one of the most important causes leading to dyszoospermia after radiation. Direct damage of ionizing radiation on cellular DNA and oxidative stress of the ionization generating peroxide water molecules are important parts of the spermatogenic cell death.We early found a molecule Iduna located in adult mice testicle spermatogonium, down-regulating in expression under the effect of ionizing radiation. Researches show that Iduna can specifically restrain PARP1 dependent Parthantos death pathways which is one of the most important ways in cell death under the action of DNA damage and oxidative stress. We found that the phenomenon of PARP1 pathways excessive activation existed in the radiation damage of testicles. Whether this phenomenon is dependent on down-regulation of Iduna ? What is the detailed mechanisms? Whether up-regulating Iduna can reduce oxidative damage of spermatogenic cell? In order to clarify these above problems, this study focus on the effect and molecular mechanism of Iduna in Parthanatos death pathway of spermatogonium radiation damage through the experiments in vivo and vitro combining with the experiment technologies of cell transfection, molecular cloning, RNAi, virus packaging, laser confocal and immunohistochemistry ,which can provide new thought for testicular radiation injury prevention and treatment.

精原细胞损伤是导致睾丸辐射后生精障碍的重要原因，而电离辐射对细胞DNA的直接损伤和水分子电离生成过氧化物引起的氧化应激是精原细胞死亡的重要环节。我们前期发现了一种定位于成年小鼠睾丸精原细胞、在电离辐射作用下表达下调的分子Iduna。研究显示Iduna能够特异性抑制PARP1依赖的Parthanatos死亡通路，后者是DNA损伤和氧化应激作用下细胞死亡的重要方式之一。我们发现辐射损伤睾丸中存在PARP1通路过度激活现象。那么电离辐射后精原细胞中PARP1通路过度激活是否与Iduna下调有关？详细机制如何？上调Iduna能否改善辐射导致的精原细胞氧化损伤？为阐明上述问题，本研究综合运用细胞转染、分子克隆、RNAi、病毒包装、激光共聚焦和免疫组化等手段，通过体内外实验探讨Iduna调控PARP1依赖的Parthanatos死亡通路对精原细胞辐射损伤的影响及分子机制，为睾丸辐射损伤防治提供新思路。

睾丸是对电离辐照高度敏感的器官，大剂量射线照射后出现不同程度睾丸功能损伤的患者越来越多，严重影响男性生殖健康。精原细胞损伤是导致大剂量射线辐照后生精障碍的重要原因，其中氧化应激损伤是精原细胞死亡的重要环节。我们发现了一种定位于成年小鼠睾丸精原细胞、在电离辐射作用下表达下调的分子 Iduna，其编码基因称为RNF146。我们发现辐射损伤的睾丸组中RNF146下调后导致 PARP1 依赖的 Parthanatos 死亡通路激活，从而引起了精原细胞的氧化损伤。上调 Iduna 能够显著改善辐射导致的精原细胞氧化损伤。我们的工作通过体内外实验初步阐明了 Iduna 调控 PARP1 依赖的 Parthanatos 死亡通路对精原细胞辐射损伤的影响及分子机制，为睾丸辐射损伤防治提供新思路。