Disease mechanism of Usher syndrome 2

亚瑟综合症2的发病机制

• 批准号: 10733709
• 负责人: Jun Yang
• 金额: $ 46.91万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10733709
• 关键词: Address; Adhesions; Affect; Affinity Chromatography; Age; Animals; Antibodies; Area; Biological Assay; Biological Markers; Blindness; COL6A1; Catalytic Domain; Cell physiology; Clinical; Co-Immunoprecipitations; Cochlea; Complex; Cone; Coupled; Cultured Cells; Cyclic AMP-Dependent Protein Kinases; Defect; Development; Disease; Electroretinography; Extracellular Matrix; Extracellular Matrix Proteins; Functional disorder; G Protein-Coupled Receptor Signaling; G-Protein-Coupled Receptors; Gene Mutation; Genes; Immunoblot Analysis; In Vitro; Individual; Inherited; Investigation; Knockout Mice; Knowledge; Label; Light; Mass Spectrum Analysis; Mediating; Membrane; Membrane Proteins; Membrane Transport Proteins; Modeling; Molecular; Molecular Chaperones; Multiprotein Complexes; Mus; Mutant Strains Mice; Mutation; Pathogenicity; Pathway interactions; Patients; Persons; Phosphorylation; Photoreceptors; Prevalence; Protein Fragment; Protein Inhibition; Proteins; Proteomics; Recombinants; Retina; Retinal Defect; Retinal Degeneration; Retinitis Pigmentosa; Role; Signal Pathway; Signal Transduction; Structure; Therapeutic; Transfection; USH2A gene; Usher Syndrome; Usher Syndrome Type 2; V1 Receptors; Vertebrate Photoreceptors; WHRN gene; Work; autosome; deaf; differential expression; early onset; effective therapy; experimental study; hearing impairment; improved; inherited retinal degeneration; insight; late-onset retinal degeneration; molecular diagnostics; mutant; novel marker; novel therapeutics; phosphoproteomics; postnatal; prevent; protein transport; response; therapeutic development; therapeutic evaluation; therapeutic target

Project Summary Retinitis pigmentosa (RP) is the predominant inherited retinal degenerative disease with a prevalence of 1 in 4,000 worldwide. RP combined with hearing loss is characterized as Usher syndrome (USH), which is the leading cause of inherited deaf-blindness. Currently, no cure is available for either RP or USH. USH2 is the most common USH clinical type. USH2A (usherin), ADGRV1 (adhesion G protein-coupled receptor V1), and WHRN (whirlin) have been identified as three USH2 causative genes. Among them, USH2A is the major causative gene for USH and autosomal recessive RP (arRP), and ADGRV1 is the second most frequent USH2 causative gene. In photoreceptors, usherin and ADGRV1 proteins interact with whirlin and form a multiprotein complex at the periciliary membrane between the inner and outer segment, but the functions of individual USH2 proteins as well as the entire USH2 complex have not been fully elucidated. This knowledge gap hinders the development of disease mechanism-based treatments. Since many patients carry USH2A mutations, the development and evaluation of therapeutics that target USH2A is an active area of investigation. However, the progress of these studies has been slowed down, because of the unknown early retinal molecular defects and late onset retinal degeneration in USH2 animal and/or in vitro retinal models. In our preliminary studies, we performed TMT-labeling quantitative proteomic and phosphoproteomic studies in USH2 mutant mouse retinas at postnatal day 30 long before retinal degeneration. We discovered alterations in photoreceptor outer segment membrane proteins, lipidated protein chaperones, BBSome and its cargos, extracellular matrix constituents, and protein kinase A signaling pathway. Affinity purification coupled with mass spectrometry experiments identified USH2 protein-interacting candidates that are enriched with proteins biologically associated with the early affected molecular and cellular processes in USH2 mutant retinas. We also found protein mislocalization and light response reduction in young USH2 mutant cones. Building on our extensive preliminary work, we propose to address the following specific aims in this application: 1) identify and investigate usherin- and ADGRV1-interacting proteins in the retina; 2) determine primary molecular defects in the retina of three different Ush2a and Adgrv1 mutant mice; and 3) uncover the molecular cause of early onset cone dysfunction in USH2 mutant retinas. If successful, our study will reveal the role of the USH2 complex in photoreceptors and provide insight into the pathogenic mechanisms underlying retinal degeneration caused by USH2 gene mutations. This study will also inform the development of mechanism-based new therapeutics for USH and arRP and discover valuable biomarkers that can be applied to therapeutic evaluation.

项目概要 色素性视网膜炎 (RP) 是主要的遗传性视网膜退行性疾病，患病率为 1% 全球 4,000 个。 RP 合并听力损失被称为 Usher 综合征 (USH)，这是一种 遗传性聋哑的主要原因。目前，RP 或 USH 尚无治愈方法。 USH2 是 最常见的 USH 临床类型。 USH2A（usherin）、ADGRV1（粘附 G 蛋白偶联受体 V1）和 WHRN (whirlin) 已被确定为三个 USH2 致病基因。其中，USH2A是主要的 USH 和常染色体隐性 RP (arRP) 的致病基因，ADGRV1 是第二常见的 USH2 致病基因。在光感受器中，Usherin 和 ADGRV1 蛋白与 Whirlin 相互作用并形成多蛋白 内节和外节之间的纤毛周膜上有复杂的结构，但各个部分的功能 USH2 蛋白以及整个 USH2 复合物尚未完全阐明。这种知识差距阻碍了 开发基于疾病机制的治疗方法。由于许多患者携带 USH2A 突变， 针对 USH2A 的疗法的开发和评估是一个活跃的研究领域。然而， 由于未知的早期视网膜分子缺陷和 USH2 动物和/或体外视网膜模型中的迟发性视网膜变性。在我们的初步研究中，我们 在 USH2 突变小鼠视网膜中进行 TMT 标记定量蛋白质组和磷酸化蛋白质组研究 出生后 30 天，早于视网膜变性。我们发现感光器外节的改变 膜蛋白、脂化蛋白伴侣、BBSome 及其货物、细胞外基质成分、 和蛋白激酶A信号通路。亲和纯化与质谱实验相结合 确定了 USH2 蛋白质相互作用候选者，这些候选者富含与生物相关的蛋白质 USH2 突变视网膜的早期影响分子和细胞过程。我们还发现蛋白质错误定位 以及年轻 USH2 突变锥体中光反应的减少。在我们广泛的前期工作的基础上，我们 建议在本申请中解决以下具体目标：1）识别并调查迎来和 视网膜中的 ADGRV1 相互作用蛋白； 2) 确定三种视网膜的主要分子缺陷 不同的Ush2a和Adgrv1突变小鼠； 3）揭示早发性视锥细胞功能障碍的分子原因 在 USH2 突变视网膜中。如果成功，我们的研究将揭示 USH2 复合物在光感受器和 深入了解USH2基因引起的视网膜变性的致病机制 突变。这项研究还将为基于机制的 USH 和新疗法的开发提供信息 arRP 并发现可应用于治疗评估的有价值的生物标志物。