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.

摘要 我的最终职业目标是成为一名研究遗传机制的独立科学家 孟德尔精神障碍的研究，希望能改善患者的治疗。具体地说，我关注的是疾病 在家族队列中发现基因，这仍然是研究正常的最有效的手段之一- 紧张性青光眼(NTG)。青光眼描述了一组以青光眼为特征的眼睛状况 视网膜神经节细胞(RGC)进行性变性，构成视神经并存在 在1-3%的成年人口中。传统的治疗方法侧重于降低眼压。 (IOP)，这是最大的可改变的风险因素。然而，NTG患者的一部分--一种诊断为 占所有青光眼病例的近三分之一，表示尽管眼压在 正常范围-在降眼压治疗后继续显示疾病进展。一个严重的障碍 开发新的治疗方法是了解NTG的分子发病机制。为此，我们团队 发现一个常染色体显性NTG家系，对降眼压治疗反应不佳。 连锁、全外显子组和全基因组分析显示，可能存在不止一个风险等位基因 在个别家庭成员中进行高效的隔离，尽管绝大多数病例似乎是 用支架/伴侣分子中高度保守残基上罕见的错义替换来解释 RPAP3蛋白。这种变异体具有很高的电子致病性分数，预计会破坏N-末端 蛋白质的结构域。N-末端结构域对刺激HSP90的ATPase活性至关重要， 另一种调控细胞外基质(ECM)产生的支架/伴侣蛋白 组件。此外，来自家族性血液样本的rna-seq显示，ecm相关基因是 在差异基因表达分析中，最不受调控的基因之一。这些观察结果支持 假设RPAP3 N-末端的中断会损害HSP90的调节，从而导致缺陷 在ECM生产/维护方面。这可能会导致正常眼压性青光眼 视神经支持结构，如筛板。我的建议旨在：(I)确定功能界别 RPAP3编码变异对HSP90相互作用/刺激和ECM基因表达的影响 (Ii)确定有害的RPAP3变异在一组被诊断为青光眼的患者中的流行率， 以及(Iii)阐明在这个大家庭中分离的其他青光眼风险变量。这一结果可能会导致 改进了NTG患者的筛查和治疗选择。通过实现这些目标，我还将 拓宽我在疾病基因发现和基因变异功能表征方面的技能，让我保持镇定 专注于人类疾病遗传学和分子诊断学的职业。