Regulation of Lysosomal pH in RPE cells

RPE 细胞中溶酶体 pH 值的调节

• 批准号: 8048058
• 负责人: CLAIRE H MITCHELL
• 金额: $ 33.68万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-02-01 至 2013-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8048058
• 关键词: ATP phosphohydrolase; Acidity; Acids; Age; Agonist; Alkalinization; Biological Assay; Cells; Cyclic AMP; Cystic Fibrosis Transmembrane Conductance Regulator; Data; Defect; Development; Ensure; Environment; Enzymes; Functional disorder; Gases; Genes; Health; In Vitro; Link; Lysosomes; Macular degeneration; Manuscripts; Mus; Mutant Strains Mice; Mutate; Mutation; Organelles; Patients; Photoreceptors; Process; Proteins; Protocols documentation; Proton Pump; Recovery of Function; Regulation; Reporting; Research; Rodent Model; Stargardt' s disease; Structure of retinal pigment epithelium; Therapeutic; Translating; Wild Type Mouse; Work; disease characteristic; early onset; enzyme activity; high throughput screening; improved; in vivo; mouse model; mutant; novel strategies; receptor coupling; repaired; restoration; treatment strategy

DESCRIPTION (provided by applicant): Lysosomal enzymes require an acidic pH to degrade engulfed material. We show here that the lysosomal pH of RPE cells from ABCA4-/- mice is elevated as compared to age matched controls. As the ABCA4 gene is mutated in Stargardt's disease, and as accumulation of partially degraded material in and around RPE cells is a key characteristic of the disease, we hypothesize that restoring an acid pH to the lysosomes will be beneficial. High-throughput screening indicates that lysosomes of perturbed RPE cells in culture are acidified by cytoplasmic cAMP, and by agonists which stimulate receptors coupled to the Gas protein. Elevation of cAMP increases the clearance of outer segments by RPE cells, demonstrating an improvement in function. This proposal investigates the contribution of cAMP, the Cl- channel CFTR, and the vesicular proton pump vH+ATPase to the restoration of lysosomal acidity. It will determine the relationship between age, A2E and lysosomal pH in RPE cells from ABCA4-/- mice and confirm that cAMP restores lysosomal acidity the these RPE cells using both in vitro and in vivo treatment strategies. PUBLIC HEALTH RELEVANCE: Stargardt's disease is an early-onset form of macular degeneration characterized by the accumulation of partially degraded material in and around RPE cells. This proposal will explore a newly identified defect in the lysosomal pH of RPE cells from the ABCA4-/- mouse model of Stargardt's disease that may slow processing of photoreceptor outer segments, develop treatments to restore this defect, and determine how these treatments work.

描述（由申请人提供）：溶酶体酶需要酸性pH以降解吞噬材料。我们在这里表明，与年龄匹配的对照组相比，来自ABCA4 - / - 小鼠的RPE细胞的溶酶体pH值升高。由于ABCA4基因在Stargardt氏病中突变，并且由于RPE细胞中部分降解的材料的积累是该疾病的关键特征，因此我们假设将酸性pH恢复到溶酶体是有益的。高通量筛选表明，培养中扰动的RPE细胞的溶酶体被细胞质cAMP酸酸，以及刺激与气体蛋白结合的受体的激动剂。 CAMP的升高会增加RPE细胞对外部段的清除，表明功能的改善。该提案研究了CAMP，CL-通道CFTR和囊泡质子泵VH+ATPase对溶酶体酸度恢复的贡献。它将确定来自ABCA4 - / - 小鼠的RPE细胞中年龄，A2E和溶酶体pH的关系，并确认CAMP使用体外和体内治疗策略恢复了这些RPE细胞的溶酶体酸度。公共卫生相关性：Stargardt的疾病是一种早期发作的黄斑变性形式，其特征在于RPE细胞中及其周围部分降解的材料的积累。该提案将探索来自Stargardt疾病的ABCA4 - / - 小鼠模型的RPE细胞溶酶体pH中新发现的缺陷，可能会减慢光感受器外部细分的处理，开发治疗以恢复该缺陷，并确定这些治疗方法的工作原理。