Validating novel candidate genes for normal-tension glaucoma

验证正常眼压性青光眼的新候选基因

• 批准号: 10749126
• 负责人: William Thomas Presley
• 金额: $ 4.08万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 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 2025-08-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10749126
• 关键词: 12q13; ATP phosphohydrolase; Adult; Affect; Biological Assay; Blindness; Blood; Blood specimen; Candidate Disease Gene; Cells; Chromosomes; Classification; Co-Immunoprecipitations; Code; Coupling; Data; Databases; Defect; Diagnosis; Disease; Disease Progression; Early treatment; Electrostatics; Escherichia coli; Extracellular Matrix; Extracellular Matrix Proteins; Family; Family member; Functional disorder; Future; Gene Expression; Gene Expression Profiling; Gene Mutation; Genes; Genetic; Genetic Diseases; Genomics; Glaucoma; Goals; Heat-Shock Proteins 90; Heritability; Impairment; In Vitro; Individual; Link; Maintenance; Mendelian disorder; Methods; Missense Mutation; Modeling; Molecular; Molecular Chaperones; Mutation; N-terminal; Normal Range; Nucleotides; Optic Atrophy; Optic Nerve; Pathogenesis; Pathogenicity; Pathway interactions; Patients; Physiologic Intraocular Pressure; Population; Positioning Attribute; Prevalence; Production; Proteins; RNA Polymerase II; Recording of previous events; Regulation; Risk; Risk Factors; Role; Running; Scaffolding Protein; Scientist; Structure; Tertiary Protein Structure; Testing; Therapeutic; Tissue-Specific Gene Expression; Variant; autosome; biobank; career; cohort; early screening; exome; experimental study; gene discovery; gene function; genetic pedigree; genetic variant; genome analysis; genome sequencing; genome wide association study; human disease; improved; in silico; member; modifiable risk; molecular diagnostics; mutant; novel; novel therapeutics; optic nerve disorder; protein protein interaction; rare variant; retinal ganglion cell degeneration; risk variant; scaffold; screening; segregation; skills; traditional therapy; transcriptome sequencing; whole genome

ABSTRACT My ultimate career goal is to become an independent scientist researching the genetic mechanisms of Mendelian disorders in hopes of improving patient therapeutics. Specifically, I am focused on disease gene discovery in familial cohorts, which remains one of the most effective means by which to study normal- tension glaucoma (NTG). Glaucoma describes a group of ocular conditions characterized by the progressive degeneration of the retinal ganglion cells (RGCs) that comprise the optic nerve and is present in 1-3% of the adult population. Traditional therapies have focused on lowering intraocular pressure (IOP), the largest modifiable risk factor. However, a subset of individuals with NTG – a diagnosis which accounts for nearly one-third of all glaucoma cases and denotes optic atrophy despite an IOP that is within normal range – continue to show disease progression after IOP-lowering treatment. A critical barrier to developing new treatments is understanding the molecular pathogenesis of NTG. To this end, our group identified a pedigree with autosomal dominant NTG that is poorly responsive to IOP-lowering therapy. Linkage, whole-exome, and whole-genome analyses revealed that there is likely more than one risk allele of high effect segregating in individual family members, though the vast majority of cases seem to be explained by a very rare missense substitution at a highly conserved residue in scaffolding/chaperone protein RPAP3. This variant, with high in silico pathogenicity scores, is predicted to disrupt the N-terminal domain of the protein. The N-terminal domain is critical for stimulating the ATPase activity of HSP90, another scaffolding/chaperone protein that modulates the production of extracellular matrix (ECM) components. Further, RNA-seq from familial blood samples revealed that ECM-associated genes were among the most dysregulated in a differential gene expression analysis. These observations support the hypothesis that disruptions in the N-terminus of RPAP3 impair HSP90 regulation, leading to defects in ECM production/maintenance. This could result in normal-tension glaucoma by compromising key optic nerve-supporting structures like the lamina cribrosa. My proposal seeks to: (i) determine the functional consequences of RPAP3 coding variants on HSP90 interaction/stimulation and ECM gene expression, (ii) determine the prevalence of deleterious RPAP3 variants in a cohort of patients diagnosed with glaucoma, and (iii) elucidate additional glaucoma risk variants segregating in this large family. The results may lead to improved screening and treatment options for NTG patients. By carrying out these aims, I will also broaden my skillset in disease gene discovery and functional characterization of genetic variants, poising me for a career focused on human disease genetics and molecular diagnostics.

抽象的 我的最终职业目标是成为研究遗传机制的独立科学家 孟德尔疾病，希望改善患者疗法。具体来说，我专注于疾病 家庭队列中的基因发现，这仍然是研究正常的最有效手段之一 张力青光眼（NTG）。青光眼描述了一组由 视网膜神经节细胞（RGC）的进行性变性，包括视神经并存在 在1-3％的成年人口中。传统疗法的重点是降低人眼压 （IOP），最大的可修改风险因素。但是，一部分NTG的个体 - 一种诊断， 占所有青光眼病例的几乎三分之一，表示视觉萎缩目的地 正常范围 - 降低IOP治疗后继续显示疾病进展。一个关键的障碍 开发新的治疗方法是了解NTG的分子发病机理。为此，我们的小组 鉴定出具有常染色体显性ntg的血统，对降低IOP疗法的反应不佳。 链接，全外观和全基因组分析表明，可能有多个风险等位基因 尽管绝大多数案件似乎是 在高度构成的脚手架/伴侣的高度构成住所中解释了非常罕见的错义替代 蛋白质RPAP3。这种变体具有高硅致病性评分，预计会破坏N末端 蛋白质的结构域。 N末端结构域对于刺激Hsp90的ATPase活性至关重要 另一种脚手架/伴侣蛋白调节细胞外基质（ECM）的产生 成分。此外，来自家族性血液样本的RNA-seq表明与ECM相关的基因是 在差异基因表达分析中最失调的是最失调的。这些观察支持 RPAP3的N末端的破坏损害HSP90调节的假设，导致缺陷 在ECM生产/维护中。这可能会导致正常的张力通过折衷钥匙 视神经支撑结构，例如lamina cribrosa。我的建议寻求：（i）确定功能 RPAP3编码变体对HSP90相互作用/刺激和ECM基因表达的后果， （ii）确定一组被诊断为青光眼的患者中有害RPAP3变体的患病率， （iii）阐明了这个大家庭中隔离的其他青光眼风险变体。结果可能导致 改善了NTG患者的筛查和治疗选择。通过执行这些目标，我也会 扩大我在疾病基因发现和遗传变异的功能表征方面的技能，使我表现 专注于人类疾病遗传学和分子诊断的职业。