Leber Hereditary Optic Neuropathy: Gene Therapy Trial

莱伯遗传性视神经病：基因治疗试验

• 批准号: 7736225
• 负责人: John Guy
• 金额: $ 87.15万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-05-01 至 2013-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7736225
• 关键词: Leber' s Hereditary Optic Neuropathy; gene therapy

DESCRIPTION (provided by applicant): Our understanding of human diseases caused by mutated mitochondrial DNA has recently evolved dramatically. This is a group of untreatable disorders affecting the eye, nervous system and heart, some that have been clinically characterized over a century ago, but they are now known to be a spectrum of molecularly defined diseases. We have chosen to start with one of the most severe, the G11778A mutation in mitochondrial DNA responsible for Leber Hereditary Optic Neuropathy (LHON) a disease group renowned for causing blindness in later childhood and early adulthood. It shows little or no propensity for recovery. In previous work we have made major strides towards determining the pathogenesis and testing a treatment for LHON. First, we discovered that ND4 mutant cells have a severe reduction in ATP synthesis, even though mild reductions in complex I activity appear insufficient to induce disease. Since no technology existed to introduce DNA directly into mitochondria, we overcame this deficiency in oxidative phosphorylation by constructing a "nuclear version" of the mitochondrial gene then targeted the cytoplasmically synthesized protein to the mitochondria by using a targeting sequence appended to the reading frame (allotopic expression). When delivered to cultured cells containing a mutant ND4, respiratory function was restored. Next, we created a bona fide animal model for LHON. Using site directed mutagenesis of the nuclear version of ND4 we replaced the codon for arginine to that for histidine at amino acid 340. Injection of this construct into the mouse visual system disrupted mitochondrial cytoarchitecture, elevated reactive oxygen species, induced swelling of the optic nerve head and induced apoptosis, with a progressive demise of ganglion cells in the retina and their axons comprising the optic nerve. In contrast, ocular expression of the wild-type human ND4 subunit appeared safe, suggesting that it may be useful for treatment of patients with LHON. Here by using the scientific and clinical knowledge acquired to date we will begin the journey towards genetic therapy for human optic neuropathy and mitochondrial disease. Our goal in this application is to test the relevance of allotopic rescue of our LHON animal model; the safety of AAV mediated delivery of the ND4 gene and the effectiveness of this therapy in preventing and restoring visual loss in our patients with LHON.

描述（由申请人提供）：我们对突变线粒体DNA引起的人类疾病的理解最近发生了巨大变化。这是一组影响眼睛、神经系统和心脏的无法治疗的疾病，其中一些在世纪前就已经有了临床特征，但现在已知它们是一系列分子定义的疾病。我们选择从最严重的线粒体DNA中的G11778 A突变开始，该突变导致Leber遗传性视神经病变（LHON），这是一种以导致儿童后期和成年早期失明而闻名的疾病。它显示出很少或没有恢复的倾向。在以前的工作中，我们在确定LHON的发病机制和测试治疗方法方面取得了重大进展。首先，我们发现ND 4突变细胞ATP合成严重减少，即使复合物I活性的轻度减少似乎不足以诱导疾病。由于不存在将DNA直接引入线粒体的技术，我们通过构建线粒体基因的“核版本”，然后通过使用附加到阅读框的靶向序列将细胞质合成的蛋白质靶向线粒体（异位表达），克服了氧化磷酸化的这种缺陷。当递送到含有突变ND 4的培养细胞时，呼吸功能恢复。接下来，我们为LHON创建了一个真正的动物模型。使用ND 4的核版本的定点诱变，我们在氨基酸340处将精氨酸的密码子替换为组氨酸的密码子。将该构建体注射到小鼠视觉系统中破坏了线粒体细胞结构，升高了活性氧，诱导了视神经乳头的肿胀并诱导了细胞凋亡，视网膜中的神经节细胞及其包含视神经的轴突逐渐死亡。相比之下，野生型人ND 4亚基的眼部表达似乎是安全的，这表明其可用于治疗LHON患者。在这里，通过使用迄今为止获得的科学和临床知识，我们将开始人类视神经病变和线粒体疾病的基因治疗之旅。我们在本申请中的目标是测试我们的LHON动物模型的同种异体拯救的相关性; AAV介导的ND 4基因递送的安全性以及这种疗法在我们的LHON患者中预防和恢复视力丧失的有效性。