调控Grx介导的αA晶状体蛋白谷胱甘肽化修饰对晶状体透明性的保护作用及其机制研究

Age-related cataract (ARC) is the leading cause of blindness in the world. αA-crystallin is important in the maintenance of lens transparency. Our previous study identified that αA-crystallin had S-glutathionylation, which mediated by glutaredoxin. Protein S-glutathionylation may depress the protein function, and there is an association between protein S-glutathionylation and ARC pathologic process. Accordingly, we speculate that αA-crystallin S-glutathionylation mediated by glutaredoxin may play an important role in the pathogenesis of ARC. This study will detect the targets site of αA-crystallin S-glutathionylation by LC-MS/MS. Molecular chaperone function, anti-apoptosis and DNA damage of S-glutathionylated αA-crystallin will be analyzed. The correlation and mechanisms between CRYAA S-glutathionylation level which mediated by GRX and risk of ARC will be detected in lens from ARC patients and animal models by immunohistochemistry. The results of the study can provide a theoretical basis of prevention and treatment of ARC.

年龄相关性白内障(ARC)是全球首位致盲性眼病。αA晶状体蛋白（CRYAA）对维持晶状体透明性起到重要作用。本项目组前期研究发现，CRYAA存在谷胱甘肽化修饰。而蛋白质谷胱甘肽化修饰可使蛋白质功能活性降低，与白内障的病理发展存在着紧密联系。前期研究还进一步证实CRYAA的修饰被谷氧还蛋白（Grx）所调节。由此推测，Grx介导的CRYAA谷胱甘肽化修饰可能在ARC发病机制中发挥了重要作用。本研究拟先确定CRYAA谷胱甘肽化修饰位点，明确谷胱甘肽化修饰对CRYAA在伴侣活性、细胞凋亡以及细胞DNA损伤等方面的影响。并进一步在年龄相关性白内障患者及白内障动物模型的晶状体组织中，明确Grx对CRYAA谷胱甘肽化修饰水平的介导作用，以及其与白内障风险的相关性，分析其调节机制，为早期干预与个体化治疗提供依据。

年龄相关性白内障（age related cataract, ARC）是世界范围内的首位致盲眼病之一。手术是目前治疗年龄相关性白内障的唯一有效途径。但深入研究年龄相关性白内障发病机理，进行早期干预，对于最大限度地保护患者视功能、提高生活质量具有重要意义。αA晶状体蛋白（αA-crystallin，CRYAA）是维持晶状体透明性的一个重要蛋白质，本研究发现CRYAA与谷氧还蛋白（Glutaredoxin，GRX）在细胞胞质中存在共定位，在白内障患者中，尤其是皮质型白内障患者的晶状体前囊膜组织样本中，CRYAA与GRX在中存在协同表达的关系， GRX可进一步通过Erk的磷酸化抑制晶状体上皮细胞内ROS的产生，从而达到其促进人晶状体上皮细胞的增殖、抑制人晶状体上皮细胞的凋亡、调节细胞周期的作用，最终达到保护晶状体透明性的作用。