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突变的动物模型产生晚期衰老表型，如骨质疏松症、心肌病、神经变性、脱发、贫血和生育力降低。虽然这些动物模型很有说服力，但不足以证明mtDNA是衰老表型的原因。如果线粒体DNA可以在体内被递送到线粒体，那么线粒体DNA在衰老中的作用就可以直接得到解决。与弗吉尼亚大学神经退行性疾病研究中心（CSND）合作，在I期STTR中，Gencia公司成功地利用了一种方法用全长mtDNA转染线粒体。这是通过使用一种新的线粒体转染技术，Protofection？（蛋白质介导的转染），由Gencia公司开发和独家拥有的技术。Protofection是一种DNA结合、非病毒递送载体，由靶向线粒体进行DNA递送的工程重组蛋白组成。超出I期研究目的的其他数据表明，原生转染可以在体内递送和表达经工程改造以表达报告蛋白（GFP，绿色荧光蛋白）的全长mtDNA，并且递送正常mtDNA可以改善由老年人受试者制成的胞质杂交（cybrid）细胞中的代谢缺陷。线粒体转染技术将mtDNA递送到线粒体的机制也被发现，并提示线粒体脂筏的存在。在这个II期STTR中，Gencia Corporation和CSND建议通过将正常mtDNA导入老年小鼠和将老年小鼠的mtDNA导入年轻小鼠来解决线粒体基因组损伤对衰老表型的贡献。提出的mtDNA转染实验将直接确定哪些方面的衰老表型是由mtDNA引起的，哪些可以通过正常mtDNA的递送来逆转。改善衰老的特定表型（可能包括肌肉减少症、认知能力下降、骨质疏松症等）的疗效将是向FDA/CBER（生物制品评价和研究中心）申请研究性新药（IND）的基础，以便在这些条件下使用mtDNA基因治疗。到2030年，65岁以上的人口将达到前所未有的20%。由于线粒体DNA中的突变可能导致许多衰老表型，因此对线粒体DNA进行治疗可以减轻这种负担。在这个II期STTR中提出的研究将直接解决线粒体DNA引起的衰老表型以及这些表型是否可以逆转。