Manipulation of Mitochondrial Genomes in Aging and Neurodegeneration

衰老和神经退行性疾病中线粒体基因组的调控

• 批准号: 7157217
• 负责人: JAMES PEPPER BENNETT
• 金额: $ 46.33万
• 依托单位: GENCIA CORPORATION
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-15 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7157217
• 关键词: DNA damage; RNA interference; age difference; aging; animal old age; animal puberty; apoptosis; biotechnology; cell line; cytotoxicity; fibroblasts; gene delivery system; gene therapy; genetically modified animals; laboratory mouse; mitochondrial DNA; mitochondrial disease /disorder; neural degeneration; oxidative stress; phenotype; platelets; technology /technique development; therapy design /development; transfection

DESCRIPTION (provided by applicant): Mitochondrial DNA (mtDNA) accumulates mutations with aging in human beings and animal models of accelerated mtDNA mutagenesis produce advanced aging phenotypes such as osteoporosis, cardiomyopathy, neurodegeneration, hair loss, anemia and reduced fertility. Though compelling, these animal models are insufficient to prove that mtDNA is responsible for aging phenotypes. If mtDNA could be delivered to mitochondria in vivo, the role of mtDNA in aging could be directly addressed. In conjunction with the Center for the Study of Neurodegenerative Disease (CSND) at the University of Virginia, in a Phase I STTR, Gencia Corporation successfully utilized a method to transfect mitochondria with full-length mtDNA. This was done by using a novel mitochondrial transfection technology, Protofection? (Protein Mediated Transfection), a technology developed and solely owned by Gencia Corporation. Protofection is a DNA-binding, non-viral delivery vector consisting of an engineered recombinant protein that targets mitochondria for DNA delivery. Additional data beyond the aims of the Phase I study show that protofection can deliver and express a full-length mtDNA engineered to express a reporter protein (GFP, Green Fluorescent Protein), in vivo and that delivery of normal mtDNA can ameliorate metabolic defects in cytoplasmic hybrid (cybrid) cells made from aged human subjects. The mechanism by which the mitochondrial transfection technology delivers mtDNA to mitochondria was also discovered and suggests the existence of mitochondrial lipid rafts. In this Phase II STTR, Gencia Corporation and the CSND propose to address the contribution of mitochondrial genomic damage to aging phenotypes by transfecting normal mtDNA into aged mice and mtDNA from aged mice into young mice. The proposed mtDNA transfection experiments will directly determine which aspects of aging phenotypes are caused by mtDNA and which can be reversed by the delivery of normal mtDNA. Efficacy in ameliorating specific phenotypes of aging (which may include sarcopenia, cognitive decline, osteoporosis and others) will be the basis of Investigational New Drug (IND) applications to the FDA/CBER (Center for Biologics Evaluation and Research) for the use of mtDNA gene therapy in these conditions. By 2030, an unprecedented 20% of the population will be over age 65. Since mutations in mitochondrial DNA may be responsible for many aging phenotypes, having a therapy for mitochondrial DNA may reduce this burden. The research proposed in this Phase II STTR will directly address what aging phenotypes are caused by mitochondrial DNA and whether these phenotypes can be reversed.

描述（由申请人提供）：线粒体DNA（mtDNA）随着人类衰老而积累突变，加速mtDNA突变的动物模型会产生晚期衰老表型，例如骨质疏松症、心肌病、神经退行性变、脱发、贫血和生育能力下降。尽管这些动物模型令人信服，但不足以证明线粒体 DNA 是导致衰老表型的原因。如果 mtDNA 可以在体内传递到线粒体，那么 mtDNA 在衰老中的作用就可以直接得到解决。 Gencia 公司与弗吉尼亚大学神经退行性疾病研究中心 (CSND) 合作，在第一阶段 STTR 中成功利用了一种用全长 mtDNA 转染线粒体的方法。这是通过使用一种新型线粒体转染技术 Protofection？ （蛋白质介导转染），一项由 Gencia Corporation 开发并独资拥有的技术。 Protfection 是一种 DNA 结合非病毒递送载体，由工程重组蛋白组成，靶向线粒体进行 DNA 递送。超出第一阶段研究目标的其他数据表明，保护转染可以在体内递送和表达全长线粒体DNA，该线粒体DNA被设计用于表达报告蛋白（GFP，绿色荧光蛋白），并且正常线粒体DNA的递送可以改善老年人类受试者的细胞质杂交（cybrid）细胞中的代谢缺陷。线粒体转染技术将 mtDNA 传递到线粒体的机制也被发现，并表明线粒体脂筏的存在。在这个 II 期 STTR 中，Gencia 公司和 CSND 提议通过将正常 mtDNA 转染到老年小鼠中并将老年小鼠的 mtDNA 转染到年轻小鼠中来解决线粒体基因组损伤对衰老表型的影响。所提出的 mtDNA 转染实验将直接确定衰老表型的哪些方面是由 mtDNA 引起的，哪些方面可以通过传递正常 mtDNA 来逆转。改善特定衰老表型（可能包括肌肉减少症、认知能力下降、骨质疏松症等）的功效将成为向 FDA/CBER（生物制品评估和研究中心）申请在这些疾病中使用 mtDNA 基因治疗的研究性新药 (IND) 的基础。到 2030 年，前所未有的 20% 人口将超过 65 岁。由于线粒体 DNA 突变可能导致许多衰老表型，因此对线粒体 DNA 进行治疗可能会减轻这一负担。 STTR II 期提出的研究将直接解决哪些衰老表型是由线粒体 DNA 引起的，以及这些表型是否可以逆转。