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.

项目摘要 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与听力损失相结合的特征是Usher综合征（USH），这是 继承聋盲的主要原因。目前，RP或USH都无法治愈。 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（旋转）已被鉴定为三个USH2致病基因。其中，USH2A是专业 USH和常染色体隐性RP（ARRP）和ADGRV1的病变基因是第二频繁的USH2 致病基因。在光感受器中，usherin和adgrv1蛋白与旋转蛋白相互作用并形成多蛋白 在内部和外部段之间的周围膜上复合物，但是个体的功能 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 基于疾病机制的治疗的发展。由于许多患者携带USH2A突变，因此 靶向USH2A的治疗剂的开发和评估是一个活跃的研究领域。但是， 由于未知的早期视网膜分子缺陷和 USH2动物和/或体外视网膜模型的视网膜变性后期发作。在我们的初步研究中，我们 在USH2突变小鼠视网膜中进行了TMT标记的定量蛋白质组学和磷酸化蛋白质组学研究 在视网膜变性前30段的产后第30天。我们发现了光感受器外部段的改变 膜蛋白，脂肪蛋白伴侣，BBSOME及其cargos，细胞外基质成分， 和蛋白激酶A信号通路。亲和力纯化与质谱实验相结合 鉴定出富含与蛋白质的蛋白质相关的蛋白质的USH2蛋白相互作用的候选者 早期影响USH2突变体视网膜中的分子和细胞过程。我们还发现蛋白质错误定位 和年轻USH2突变锥的光响应减少。在我们广泛的初步工作的基础上，我们 建议在本应用程序中解决以下具体目的：1）识别和调查Usherin-和 视网膜中的ADGRV1相互作用蛋白； 2）确定三个视网膜中的一级分子缺陷 不同的USH2A和ADGRV1突变小鼠； 3）发现早期发作锥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复合物在感光体中的作用 洞悉由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USH和 ARRP并发现可用于治疗评估的有价值的生物标志物。