YARS2基因变异导致线粒体功能异常在耳聋发病机制中的作用

耳聋是全球性重大公共卫生问题之一，超过50%的患者是由遗传因素造成的。前期研究发现YARS2基因通过加重线粒体tRNA突变相关的线粒体功能障碍调控耳聋表型；且斑马鱼yars2基因敲除后，其听觉和平衡功能发生障碍。提示YARS2基因可能参与听觉发育和功能，但具体机制尚不明确。因此，本项目在此基础上将开展以下研究：1、进一步在感音神经性耳聋患者中开展YARS2基因突变筛查，绘制中国人群的突变频谱和表型谱；2、在细胞水平上研究YARS2基因突变对蛋白表达和功能、细胞代谢和功能的影响；3、基于CRISPR/Cas9技术构建斑马鱼yars2突变体模型，分析yars2敲除及定点突变后斑马鱼相关器官形态功能改变，评估其在听觉发育中的作用，研究YARS2基因突变的发病机制并诠释其组织特异性致病机制。本项目的实施为耳聋的诊断和防治提供新的理论依据，也将为遗传性耳聋和其他线粒体疾病的致病机制研究提供借鉴。

Deafness is a major public health problem worldwide,and more than 50% of cases of deafness are due to genetic factors. Our previous studies showed that YARS2 mutation aggravated the mitochondrial dysfunction associated with mitochondrial tRNA mutation, and led to higher penetrability of deafness. Moreover, the hearing and balance function were impaired in zebrafish when yars2 gene were knocked out. These data indicate that YARS2 may affect the development and function of hearing, but the specific mechanism is still unclear.This project is designed to further study the important role of YARS2 on hearing function and its molecular pathogenesis mechanism. First, we will further carry out mutational screening on YARS2 gene in patients with deafness, and clarify the mutation and phenotype spectrum in Chinese population. The second aim is to investigate the effects of YARS2 mutation on protein expression and function, cell metabolism and function based on the lymphocytes lines derived from the deafness individuals with YARS2 mutation. Finally, we will generate the knock-out and knock-in zebrafish models for orthologous gene YARS2 based on CRISPR/cas9 gene editing technology. By comparative study of the developmental, morphological and functional changes of auditory organ and line system in the knock-out and the knock-in zebrafish models in vivo, we will identify the role of yars2 gene in the hearing development of zebrafish, and explore the molecular mechanism of different yars2 gene mutations and its tissue-specific pathogenesis. The implementation of this project will provide valuable information for the diagnosis and prevention of deafness, and also provide important insights into the pathogenesis of hereditary deafness and other mitochondrial diseases.