Succinyl-COA Synthetase Deficiency: A Model to Study Mitochondrial DNA (MTDNA) De

描述(由申请人提供)： 线粒体肌病伴线粒体DNA(MtDNA)耗竭是一类重要的新发现的线粒体疾病，可导致代谢性肌病以及智力和发育障碍。ADP特异性琥珀酰辅酶A合成酶(SCS)是TCA循环的一个组成部分，它的缺失被认为是线粒体肌病mtDNA缺失的原因之一。已分离到编码SCSβ亚基基因Sucla2的基因陷阱突变克隆。这个突变的小鼠ES细胞系已经被用来产生转基因小鼠和缺乏Sucla2的小鼠胚胎成纤维细胞(MEF)细胞系。突变的MEF以及突变的胚胎骨骼肌和大脑显示线粒体DNA耗尽。这一建议是基于这样的假设，即SCS是mtDNA核状复合体的重要蛋白质成分，是mtDNA维持和稳定所必需的。缺乏SUCLA2的细胞将被用来研究线粒体DNA维持所需的SUCLA2的功能和结构成分。还将进行基因研究，以确定与SCS相互作用的蛋白质，并确定mtDNA类核复合体的潜在成分。将产生Sucla2的突变小鼠，以研究SCS缺乏的病理生理学，作为线粒体DNA耗竭和肌病的模型。这些研究将为线粒体DNA生物学的基本机制提供新的见解，并提供一个新的线粒体DNA耗竭模型，以促进针对一种重要的代谢性肌病亚型的新治疗策略的开发。 公共卫生相关性： 叙述性线粒体DNA(MtDNA)总含量耗尽或减少是一组线粒体疾病的特征，在乳腺癌中也观察到了这一特征。线粒体DNA耗竭的细胞和动物模型的建立对于理解线粒体DNA耗竭的病理机制以及了解线粒体DNA生物学的基本机制具有重要意义。本项目建立了一个研究线粒体DNA耗竭的模型，并探索线粒体DNA维持的基本机制，以最终开发出治疗线粒体DNA耗竭疾病的新策略。

DESCRIPTION (provided by applicant): Mitochondrial myopathy with mitochondrial DNA (mtDNA) depletion is an important and newly recognized class of mitochondrial disease that causes metabolic myopathy as well as intellectual and developmental disabilities. Deficiency of ADP-specific succinyl-CoA synthetase (SCS), a component of the TCA cycle, has been identified as one of the causes of mitochondrial myopathy with mtDNA depletion. A gene trap mutant clone of Sucla2, the gene encoding the beta-subunit of SCS, has been isolated. This mutant mouse ES cell line has been used to generate transgenic mice and mouse embryonic fibroblast (MEF) cell lines deficient for Sucla2. Mutant MEFs as well as mutant embryonic skeletal muscle and brain demonstrate mtDNA depletion. This proposal is based on the hypothesis that SCS is an important protein component of the mtDNA nucleoid complex required for mtDNA maintenance and stability. Cells deficient for SUCLA2 will be utilized to investigate the functional and structural components of SUCLA2 required for mtDNA maintenance. Genetic studies to determine proteins that interact with SCS and are potential components of the mtDNA nucleoid complex will also be pursued. Mice mutant for Sucla2 will be generated to study the pathophysiology of SCS deficiency as a model for mtDNA depletion and myopathy. These studies will provide new insights into fundamental mechanisms of mtDNA biology as well as provide a novel model of mtDNA depletion to facilitate the development of new therapeutic strategies for an important subset of metabolic myopathies. PUBLIC HEALTH RELEVANCE: Narrative Depletion or reduction of total content of mitochondrial DNA (mtDNA) is a feature of a subset of mitochondrial diseases and has also been observed in breast cancer. The development of cell and animal models of mtDNA depletion is important for understanding the pathological mechanisms of mtDNA depletion as well as for understanding fundamental mechanisms of mtDNA biology. This project establishes a model to study mtDNA depletion and to explore basic mechanisms of mtDNA maintenance in order to ultimately develop novel therapeutic strategies for diseases with mtDNA depletion.