Molecular Remedy of Mitochondrial Defects

描述(申请人提供)：这笔赠款的总体目标是为线粒体氧化磷酸化系统缺陷引起的疾病寻求分子疗法。复合体I是组成氧化磷酸化系统的五种酶复合体中的第一个。它具有最复杂的结构，有45个不同的亚基(其中7个亚基是线粒体编码的(命名为ND1-6和4L))，一个FMN和8个铁-硫簇作为辅助因子。复杂的I基因缺陷与许多人类线粒体疾病有关。Leber遗传性视神经病变(LHON)是公认的多发病的复杂性I型疾病。一种新的动物模型已经被开发出来，包括将鱼藤酮生物珠注入大鼠大脑的上丘。在动物身上观察到了典型的LHON症状，最明显的是严重损害了视力。同时，RGC结节明显解体，RGC轴突脱髓鞘。然而，视力丧失并不伴随LHON的特征，如视网膜神经节细胞(RGC)层变薄和RGC死亡，这些特征仅发生在LHON的晚期。此外，将酵母NADH脱氢酶基因(NDI1)导入大鼠脑内，可使大鼠视力恢复到正常水平，同时伴随着Ranvier结节的重组和RGC轴突的重新髓鞘形成。这些发现构成了本研究项目的基础。在这一资助期限内，LHON的研究将集中于以下具体目标。(1)用突变的人或大鼠ND4基因视网膜注射或上丘鱼藤酮生物珠滴注法建立大鼠LHON模型，探讨LHON的发病机制。(2)明确NDI1基因表达是否能修复两种LHON模型的视力损失，并确定修复窗口。(Iii)构建携带突变的人或鼠ND4基因的转基因小鼠株，为进一步研究LHON的触发因素等奠定基础。

DESCRIPTION (provided by applicant): The overall goal of this grant is to seek molecular therapies for diseases resulting from defects of the mitochondrial oxidative phosphorylation system. Complex I is the first of five enzyme complexes that comprise the oxidative phosphorylation system. It has the most intricate structure with 45 different subunits (of these, 7 subunits are mitochondrially encoded (designated ND1-6 and 4L)), one FMN and eight iron- sulfur clusters as cofactors. Complex I defects are involved in many human mitochondrial diseases. Leber's hereditary optic neuropathy (LHON) is recognized as the frequently occurring complex I disease. A new animal model has been developed that involves infusion of rotenone-biobeads into the superior colliculus of the rat brain. Symptoms typical of LHON were observed in the animals, most notably, severely impaired vision. At the same time, there was clearly disorganization of the node of Ranvier as well as demyelination of the RGC axons. However, loss of vision was not accompanied by the hallmarks of LHON such as thinner retinal ganglion cell (RGC) layer and death of RGC which only occurred at a later stage. Furthermore, delivery of the yeast alternative NADH dehydrogenase gene (NDI1) into the rat brain restored the vision to normal level with concomitant reorganization of the node of Ranvier and remyelination of the RGC axons. These findings form the basis of this research project. During this grant term, focus will be made on LHON research with the following specific aims. (i) To investigate mechanism of LHON by using the rat models by administration of mutated human or rat ND4 gene to the retina or rotenone biobeads infusion in the superior colliculus. (ii) To clarify whether the NDI1 gene expression can repair vision loss of the two LHON models and to determine repair window. (iii) To construct transgenic mouse strains carrying the mutated human or mouse ND4 gene for further investigation of LHON such as triggering factors.