Exploring the pathophysiology and treatment of LCHADD retinopathy

探索 LCHADD 视网膜病变的病理生理学和治疗

基本信息

批准号：
10470841
负责人：
Melanie B Gillingham
金额：
$ 37.35万
依托单位：
OREGON HEALTH & SCIENCE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-01 至 2026-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10470841
关键词：
3-Hydroxyacyl-CoA dehydrogenase Address Animals Blindness Blood CRISPR/Cas technology Cell Culture Techniques Cell Differentiation process Cells Cessation of life Child Childhood Chronic Coculture Techniques Color Visions Complication Defect Deterioration Development Diet therapy Disease Early Diagnosis Early Intervention Early treatment Electroretinography Exhibits Experimental Models Fatty Acids Fibroblasts Functional disorder Future Gene Transfer Genes Genetic Goals Hepatic Hydrogen Peroxide Impairment In Vitro Ketones Knock-in Light Lipids Liver Mediating Metabolic Mitochondria Modality Modeling Molecular Mus Muscle Mutation Natural History Neonatal Screening Organ Outcome Oxidative Stress Oxides Oxidoreductase Palmitates Pathologic Pathology Patients Peripheral Phenotype Photoreceptors Pigments Plasma Point Mutation Predisposition Production Protein Deficiency Recombinant adeno-associated virus (rAAV)Retina Retinal Degeneration Retinal Diseases Retinal Pigments Retinal gene therapy Role Series Structure Structure of retinal pigment epithelium Testing Time Toxic effect Toxin Vision Visual Acuity Wild Type Mouse acylcarnitine adeno-associated viral vector cell type design experimental study fatty acid oxidation gene therapy human disease in vitro Model induced pluripotent stem cell macula mouse model mutant mouse model novel novel therapeutics oxidation oxidative damage preservation prevent response restoration retinal damage visual performance

项目摘要

Project Summary Progressive retinopathy with vision loss is a unique complication of Long-chain 3-Hydroxyacyl-CoA Dehydrogenase Deficiency (LCHADD) and mitochondrial Trifunctional Protein Deficiency (TFPD), rare genetic fatty acid oxidation (FAO) disorders. Gradual macular pigment clumping, followed by progressive deterioration of the retina occurs in almost all LCHADD patients beginning in childhood and progressing over time. This manifests initially as decreased night vision, progresses to loss of color vision, and ultimately to decreased central vision. While early diagnosis through newborn screening and sustained dietary therapy can slow progression, no successful treatment directed at retinopathy currently exists, and children with LCHADD/TFPD continue to suffer progressive blindness. Novel treatments for LCHADD-associated retinopathy are needed but appropriate experimental models have been lacking. We recently created 2 models of LCHADD-retinopathy; a murine knockin of c.1528G>C, the common mutation in the HADHA gene that causes LCHADD, and cultured RPE-like cells differentiated from induced pluripotent stem cells (iPSC) derived from patients' fibroblasts. The pathophysiology of LCHADD-associated retinopathy is not completely understood but begins with loss of retinal pigment epithelium (RPE). Two potential molecular mechanisms include; energy deficit due to decreased FAO to support normal RPE functions, or selective toxicity of accumulating partially oxidized fatty acid metabolites. Children with lower blood concentrations of LCHADD-specific 3-hydroxy-acylcarnitines have preserved retinal function implying that retinal damage may be mediated through accumulation of toxic fatty acid intermediates. If so, then gene therapy directed toward a peripheral organ such as muscle or liver could lower circulating toxic metabolites, prevent retinal degeneration, and address other LCHADD-associated complications. Alternatively, retinal preservation may require the restoration of LCHAD activity directly in RPE, and circulating acylcarnitines are simply a marker of partial FAO in the retina. We will use our 2 models of LCHADD-retinopathy to test which approach will prevent RPE dysfunction and retinal degeneration. LCHADD-RPE exhibit decreased ability to oxidize palmitate, accumulated acylcarnitines and neutral lipids, and increased susceptibility to H2O2 oxidative stress in comparison to wild type (WT) RPE. We propose a series of experiments to test LCHADD-associated RPE alterations such as lipid processing and sensitivity to H2O2 treatment under different FAO conditions compared to WT RPE. Additionally, the LCHADD-mouse has decreased visual performance and electroretinogram (ERG) responses compared to WT mice. Our goal is to characterize the visual acuity, retinal structure and function of LCHADD mice and to test the effects of hepatic versus retinal directed gene therapy approaches. The outcome of these experiments will expand our understanding of LCHAD-specific pathology and provide the basis for a translational effort to treat LCHADD retinopathy, potentially with retinal gene therapy, a new treatment modality of which OHSU is a national leader.

项目摘要渐进性视网膜病与视力丧失是长链3-羟基乙酰辅酶A的独特并发症脱氢酶缺乏症（LCHADD）和线粒体三官能蛋白缺乏症（TFPD），稀有遗传脂肪酸氧化（FAO）疾病。渐进的黄斑色素块，然后进行性降解视网膜的发生在几乎所有从儿童期开始并随着时间发展而发展的LCHADD患者。这最初表现出随着夜视的降低，发展为彩色视觉的丧失，最终降低中央视觉。而通过新生儿筛查和持续饮食疗法的早期诊断会减慢进展，目前没有针对视网膜病的成功治疗，患有LCHADD/TFPD的儿童继续遭受进步的失明。需要针对LCHADD相关视网膜病的新型治疗方法缺乏适当的实验模型。我们最近创建了两种lchadd-retinopathy模型；一个 C.1528G> C的鼠敲击素，导致LCHADD和培养的Hadha基因中的常见突变 RPE样细胞与衍生自患者成纤维细胞的诱导多能干细胞（IPSC）区分开。 LCHADD相关视网膜病的病理生理并不完全了解，但始于视网膜色素上皮（RPE）的丧失。两个潜在的分子机制包括：由于能源不足减少粮农酸代谢物。血液浓度较低的LCHADD特异性3-羟基 - 酰基脂蛋白的儿童具有保留的视网膜功能表明可以通过积累有毒脂肪来介导视网膜损伤酸中间体。如果是这样，则针对外周器官（例如肌肉或肝脏）的基因治疗可以下循环的有毒代谢产物，防止视网膜变性，并解决其他与LCHADD相关的并发症。另外，视网膜保存可能需要直接在RPE中恢复LCHAD活性，循环酰基肉碱只是视网膜部分粮农组织的标志。我们将使用我们的两种型号 LCHADD-RETINOPARTY用于测试哪种方法可以防止RPE功能障碍和视网膜变性。 LCHADD-RPE表现出降低氧化棕榈酸酯，累积酰基炭干和中性的能力与野生型（WT）RPE相比，脂质和对H2O2氧化应激的敏感性增加。我们建议一系列测试与LCHADD相关的RPE改变的实验，例如脂质加工和对与WT RPE相比，在不同的粮农组织条件下的H2O2处理。此外，LCHADD-MOUSE有与WT小鼠相比，视觉性能和电视图（ERG）反应的降低。我们的目标是表征LCHADD小鼠的视力，视网膜结构和功能，并测试肝的影响与视网膜定向基因治疗方法相比。这些实验的结果将扩大我们的了解LCHAD特异性病理，并为转化努力治疗LCHADD提供了基础视网膜病变，可能是视网膜基因疗法，这是一种新的治疗方式，OHSU是国家领导者。