Gene therapy to support cone metabolism in retinitis pigmentosa

支持色素性视网膜炎视锥细胞代谢的基因疗法

基本信息

批准号：
8622203
负责人：
CONSTANCE L CEPKO
金额：
$ 41.53万
依托单位：
HARVARD MEDICAL SCHOOL
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-03-01 至 2016-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8622203
关键词：
Address Affect Age related macular degeneration Antioxidants Area Autophagocytosis Binding Proteins Biogenesis Biological Preservation Blindness Carbon Cessation of life Charge Clinical Trials Color Cone Disease Drug Metabolic Detoxication Environment Enzymes Equilibrium Eye Free Radicals Gene Combinations Generic Drugs Genes Genetic Glucose Glucose Transporter Glutathione Human Injection of therapeutic agent Insulin Ions Isocitrate Dehydrogenase Lead Lesion Lipids Mediating Membrane Metabolic Metabolic stress Metabolism Mitochondria Modeling Molecular Chaperones Monocarboxylic Acid Transporters Mus NADP Nuclear Nucleic Acids Nutrient Outcome Oxidoreductase PPAR gamma Pathway interactions Patients Pentosephosphate Pathway Phosphorylation Photoreceptors Phototransduction Proteins Quality of life Regulation Regulator Genes Regulatory Element Retina Retinal Cone Retinitis Pigmentosa Sterols Stress Superoxide Dismutase Surface Viral Vector Vision Work adeno-associated viral vector catalase cell type combat experience fighting gene therapy human FRAP1 protein malic enzyme mouse model oxidation programs public health relevance retinal rods sugar transcription factor

项目摘要

DESCRIPTION (provided by applicant): Blindness is often caused by genetic lesions that directly affect photoreceptors. There are >200 disease genes in humans that lead to blindness (retnet:www.sph.uth.tmc.edu/Retnet). Addressing each genetic deficit by transduction of a gene specific to that disease would be a large and expensive undertaking. As an alternative, gene therapy can be used to attack a problem common to multiple genetic forms of blindness. One such approach is to preserve cone function in retinitis pigmentosa (RP). People with RP initially have poor night vision, as rods are dysfunctional. Rods are then lost, which is followed by loss of cone function, and then cones themselves. As cones do not express the disease gene in most cases, there must be a non-autonomous cause of cone death. If this cause can be identified, and combated, a more generic form of therapy can be developed. Using 4 mouse models of RP, and an unbiased microarray approach, we discovered that many genes involved in the regulation of metabolism were altered at the onset of cone death. We further showed that mTOR, a key regulator of metabolism, was not phosphorylated in RP cones. This is now the earliest sign of cone stress in RP that is known. As the disease progressed, we discovered that cones carried out chaperone- mediated autophagy. Injection of insulin into RP mice, which can lead to increased activity of mTOR, increased survival of cones. We have suggested a model wherein cones are dysfunctional and then die due to dysregulated metabolism. As rods are the major cell type in the ONL, cones experience a greatly altered environment following rod death. The cone OS collapse, they lose their intimate association with the RPE, and they are exposed to a hyperoxic environment. They show greater oxidation of their nucleic acids, proteins, and lipids. Fighting oxidation may cause cones to require more NADPH, which is generated from glucose via the pentose phosphate pathway (PPP). It is also produced by two cytosolic enzymes, malic enzyme and isocitrate dehydrogenase. If glucose is shuttled to the PPP, the glycolytic pathway would slow, which could lead to several metabolic outcomes, including reducing the surface area of cones, as well as reducing phototransduction and potentially the ATP levels. We wish to develop AAV-mediated gene therapy to combat metabolic stress in the cones in RP. As cone-mediated vision is of greatest importance to humans, preservation of cone function is critical to the quality of life among RP patients. If such therapies can be developed, it is also possible that these therapies can be extended to other diseases where cones are compromised, such as age-related macular degeneration (AMD).

描述（由申请人提供）：失明通常是由直接影响光感受器的遗传病变引起的。人类中有200个疾病基因导致失明（retnet：www.sph.uth.tmc.edu/retnet）。通过转导针对该疾病的基因来解决每个遗传缺陷，这是一项巨大而昂贵的事业。作为替代方案，基因治疗可用于攻击多种遗传形式失明的问题。一种方法是保留色素性视网膜炎（RP）中的锥体功能。 RP的人最初的夜视范围很差，因为杆功能失调。然后丢失了杆，随后是圆锥功能的损失，然后是锥本身。由于锥体在大多数情况下没有表达疾病基因，因此必须存在锥形死亡的非自主原因。如果可以识别出此原因和打击，则可以开发出更通用的治疗形式。使用4种RP的小鼠模型和一种无偏的微阵列方法，我们发现在锥死亡开始时，许多与代谢调节有关的基因都发生了变化。我们进一步表明，MTOR是代谢的关键调节剂，在RP锥中未磷酸化。现在，这是RP中最早的锥质压力迹象。随着疾病的发展，我们发现锥进行了伴侣介导的自噬。将胰岛素注射到RP小鼠中，这可能导致MTOR的活性增加，增加了锥体的存活率。我们提出了一个模型，其中锥体功能失调，然后由于代谢失调而死亡。由于杆是ONL的主要细胞类型，因此圆锥体经历了杆死亡后的环境发生了巨大变化。圆锥体崩溃，他们失去了与RPE的亲密关联，并且暴露于过度氧气环境中。它们显示出更大的核酸，蛋白质和脂质的氧化。对抗氧化可能会导致锥体需要更多的NADPH，这是通过葡萄糖通过五磷酸五磷酸途径（PPP）产生的。它也是由两种胞质酶，苹果酶和异位酸脱氢酶产生的。如果将葡萄糖穿梭至PPP，则糖酵解途径将减慢，这可能导致几种代谢结果，包括减少锥体的表面积，并降低光转移的表面效果以及潜在的ATP水平。我们希望开发AAV介导的基因疗法，以打击RP中锥的代谢应激。由于锥体介导的视力对人类至关重要，因此保存锥功能对于RP患者的生活质量至关重要。如果可以开发此类疗法，这些疗法也可以扩展到锥体受损的其他疾病，例如与年龄相关的黄斑变性（AMD）。