Molecular Remedy of Mitochondrial Defects

描述（由申请人提供）：该基金的总体目标是寻求线粒体氧化磷酸化系统缺陷引起的疾病的分子疗法。复合物I是构成氧化磷酸化系统的五种酶复合物中的第一种。它具有最复杂的结构，具有45个不同的亚基（其中，7个亚基是同源编码的（命名为ND 1 -6和4L））、一个FMN和8个铁-硫簇作为辅因子。复合物I缺陷涉及许多人类线粒体疾病。Leber遗传性视神经病变（LHON）是公认的最常见的复杂I型疾病。已经开发了一种新的动物模型，该模型涉及将鱼藤酮生物珠注入大鼠大脑的上级丘。在动物中观察到LHON的典型症状，最显著的是视力严重受损。与此同时，有明确的破坏的节点的Ranvier以及脱髓鞘的RGC轴突。然而，视力丧失并不伴随LHON的特征，例如视网膜神经节细胞（RGC）层变薄和仅在后期发生的RGC死亡。此外，交付的酵母替代NADH脱氢酶基因（NDI 1）到大鼠脑恢复视力正常水平，伴随着重组的节点的Ranvier和髓鞘再生的RGC轴突。这些发现构成了本研究项目的基础。在此期间，重点将放在LHON研究与以下具体目标。(i)通过视网膜注射突变的人或大鼠ND 4基因或上级丘注射鱼藤酮生物微球建立大鼠LHON模型，探讨LHON的发病机制。(ii)明确NDI 1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)目的构建携带ND 4基因的转基因小鼠，为进一步研究LHON的诱发因素奠定基础。

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.