基于MARCH1对PARL蛋白泛素化修饰探讨铝暴露导致弱精子症的致病机制

弱精子症病因十分复杂，且临床上尚停留在较低水平的诊断和治疗方式。申请人所处区域为铝工业基地，前期流行病学调查发现长期从事铝相关作业人员精子活力较低，精子受损率较高，精子线粒体中PARL蛋白水平降低；生信分析与预实验发现PARL蛋白抑制VDAC进而调控线粒体通透性及相关凋亡因子释放，而MARCH1作为PARL泛素修饰酶在铝暴露后显著上调。由此推测：铝暴露上调MARCH1促进其对PARL泛素化降解，使得VDAC抑制信号减弱线粒体通透性增强导致细胞凋亡因子SMAC等释放促进精子凋亡。申请人拟通过从临床、体内与分子三个层面综合运用co-IP、氨基酸点突变、双荧光蛋白共定位等手段完成以下研究目标：评价铝暴露作为导致弱精子症的独立风险因素；探讨铝暴露对精子活力以及精子细胞凋亡作用；明确MARCH1泛素化降解PARL介导线粒体通透性改变促进精子凋亡。从而为铝暴露所致弱精子症临床诊疗提供新的策略。

Asthenospermia is still at a low level of diagnosis and treatment, which is mainly due to the complex etiology of decreased sperm motility.The applicant is located in the aluminum industry base, and the preliminary epidemiological survey found that the long-term aluminum-related workers had lower sperm motility, higher sperm damage rate and lower levels of PARL protein in sperm mitochondria. Letter analysis and preliminary experiments found PARL proteins inhibit VDAC regulation of mitochondrial permeability and related apoptosis factor then released, but MARCH1 as PARL ubiquitin rise significantly after modification enzyme in aluminum exposed, thus the applicant to speculate that aluminum raised MARCH1 promote its exposure to PARL ubiquitin degradation, makes the VDAC weakened inhibition of signal mitochondrial permeability enhanced apoptosis factors such as SMAC release sperm apoptosis.The applicant intends to use co-ip, amino acid point mutation, double fluorescent protein co-localization and other means comprehensively from the clinical, in vivo and molecular levels to accomplish the following research objectives: evaluate aluminum exposure as an independent risk factor for asospermia; investigate the effects of aluminum exposure on sperm motility and sperm cell apoptosis; confirme that MARCH1 ubiquitination degradation of PARL mediates mitochondrial permeability change to promote sperm apoptosis. So as to provide a new target for clinical diagnosis and treatment of asthenospermia caused by aluminum exposure.