线粒体tRNAThr基因突变通过线粒体自噬调控Leber遗传性视神经病变的机制研究

Leber遗传性视神经病变（LHON）是一种视网膜神经节细胞（RGCs）及其轴索受损的母系遗传病。线粒体DNA突变是LHON的主要分子基础，但由于缺乏理想的线粒体疾病模型，突变导致LHON的机制尚不明确。前期研究表明，线粒体自噬与线粒体tRNAThr15927G>A相关LHON有关。本项目拟以患者特异性诱导多能干细胞（iPSCs）为模型，将其定向分化为RGCs，聚焦“m.15927G>A通过线粒体自噬影响RGCs功能导致LHON的发生”这一科学假说，从以下三方面进行研究：（1）明确突变对iPSCs诱导及定向分化RGCs形态和功能的影响；（2）阐明突变通过PINK1/Parkin介导的线粒体自噬调控LHON的分子机制；（3）利用转线粒体技术建立突变矫正的iPSCs模型，反向验证突变对RGCs形态和功能的影响。本项目的实施不仅有助于诠释LHON的发病机制，也将为临床转化提供科学依据和技术支撑。

Leber’s hereditary optic neuropathy (LHON) is a maternally inherited eye disease with selective degeneration of retinal ganglion cells (RGCs) and their axons. Mutations in mitochondrial DNA (mtDNA) are responsible for this disease. However, due to the lack of appropriate models, the mechanism of LHON associated with mtDNA mutations is less understood. Our previous studies showed that mitophagy was associated with LHON carrying mitochondrial tRNAThr 15927G>A. This project will establish the patient-specific induced pluripotent stem cells (iPSCs), then differentiate them into retinal ganglion cells (RGCs), and focus on the scientific hypothesis that m.15927G>A influences the function of RGCs and leads to the occurrence of LHON through mitophagy. The following three aspects will be investigated. Firstly, the changes of morphology and function in specific iPSCs and directional differentiation RGCs with m.15927G>A mutation will be analyzed. Secondly, PINK1/Parkin-induced mitophagy play an important role in the course of LHON. Thirdly, using modified iPSCs model by transmitochondrial technology in patient derived cells could regenerate the functional RGCs. That will provide the evidence in the effect of mutations on RGCs morphology and function from the other side. Thus, success of this project will contribute to the understanding of the pathogenesis of LHON and provide valuable information and technology for the development of intervention and therapeutic interventions of LHON.