Mouse Models of Mitochondrial Encephalomyopathies

描述(由申请人提供)：氧化磷酸化缺陷(OXPHOS)与各种神经肌肉退变过程有关。我们建议利用目前的方法，允许操纵胚胎干细胞中的核基因，并建立和表征具有核编码的OXPHOS基因条件突变的小鼠模型。这项提案将检验的一般假设和问题是：i)敲除因子对OXPHOS的组装和功能有什么具体作用？Ii)不同的细胞群是否更容易受到特定OXPHOS复合体缺陷的影响？肌肉或神经中特定呼吸链复合体的缺陷是否会导致不同的肌肉或神经退化表型？IV)这些表型是否与不同程度的氧化损伤或蛋白质聚集有关？具体地说，我们将培育三个呼吸复合体基因的敲入小鼠，在这些基因中，一个进化上保守的外显子两侧是IoxP位点。以下基因将被操纵：NDUFS1基因(复合体I)，铁硫蛋白(复合体III)和COX10，一种原血红素O法尼基转移酶(产生血红素a和复合体IV活性所必需的)。敲门动物将与由中枢神经系统和骨骼肌启动子驱动的表达Cre重组酶的小鼠杂交。我们希望这些研究能提供证据，证明OXPHOS中的特定缺陷可以表现为明显的表型变化。

DESCRIPTION (provided by applicant): Defects in oxidative phosphorylation (OXPHOS) have been associated with various neuromuscular degenerative processes. We propose to take advantage of current methodology that allows the manipulation of nuclear genes in embryonic stem cells and generate and characterize of mouse models with conditional mutations in nuclear-coded OXPHOS genes. The general hypotheses and questions this proposal will test are: i) What are the specific role of the knocked out factors on OXPHOS assembly and function? ii) Are different cell populations more susceptible to defects in specific OXPHOS complexes? iii) Do defects in specific respiratory chain complexes in muscle or nerves lead to different muscular or neurodegenerative phenotypes? iv) Are these phenotypes associated with different levels of oxidative damage or protein aggregation? Specifically, we will develop knock in mice for three respiratory complex genes in which an evolutionarily conserved exon is flanked by IoxP sites. The following genes will be manipulated: the NDUFS1 gene (complex I), Iron-Sulfur Protein (complex III) and COX10, a protoheme O farnesyl-transferase (required for heme a production and complex IV activity). The knockin animals will be crossed with mice expressing Cre-recombinase driven by CNS and skeletal muscle promoters. We expect these studies to provide evidence that specific defects in the OXPHOS can manifest as distinct phenotypic alterations.