Understanding SHRF, an RNA exosome-linked disease with multi-organ involvement

了解 SHRF，一种与 RNA 外泌体相关的多器官受累疾病

• 批准号: 10305689
• 负责人: Bingwei Lu
• 金额: $ 23.61万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-12-01 至 2022-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10305689
• 关键词: 9q34; Address; Affect; Animal Model; Atrophic; Autophagocytosis; Biological Models; Biology; Birth; Brain imaging; Cell Culture Techniques; Cell Nucleus; Cell model; Cell physiology; Cerebellar Cortex; Chromosomes; Complex; Defect; Dentate nucleus; Disease; Disease model; Drosophila genus; Engineering; Enzymes; Eukaryotic Cell; Exhibits; Face; Facies; Funding Opportunities; Genes; Genetic; Genomics; Hearing; Human; Inferior; Institutes; Intellectual functioning disability; KH Domain; Knowledge; Label; Lead; Light; Link; Maintenance; Malignant Neoplasms; Mammalian Cell; Mission; Modeling; Muscle; Mutation; Neonatal; Neurodegenerative Disorders; Neurons; Olives - dietary; Pathogenesis; Patients; Peroxidases; Pontine structure; Pontocerebellar hypoplasia; Positioning Attribute; Post-Transcriptional Regulation; Process; Proteins; Pulmonary Fibrosis; RNA; RNA Binding; RNA-Binding Proteins; Regulation; Research; Retinitis Pigmentosa; Rewards; Ribonucleases; Risk; Role; Signal Pathway; Structure; Testing; Tissues; Transcript; United States National Institutes of Health; Visual; Visual impairment; ascorbate; base; body system; cell type; disease phenotype; exosome; experience; fetal; fly; hearing impairment; in vivo; induced pluripotent stem cell; insight; keratinocyte; myelination; nervous system development; new technology; novel; scaffold

Project Summary Short stature, hearing loss, retinitis pigmentosa, and distinctive facies (SHRF) is a rare autosomal recessive disorder characterized by short stature, brachydactyly, dysmorphic facial features, hearing loss, and visual impairment. Patients also exhibit mild intellectual disability. SHRF is caused by homozygous or compound heterozygous mutation in the EXOSC2 gene, which encodes a subunit of the RNA exosome complex, a conserved multi-subunit ribonucleolytic complex that controls the 3´ to 5´ processing and degradation of various RNAs in all eukaryotic cells. Nine subunits (EXOSC1-9) form a catalytically inert core that serves as a scaffold for two ribonuclease subunits (EXOSC10 and Dis3). EXOSC2 and EXOSC3 are S1 and KH domain containing RNA-binding proteins that form the exosome cap structure. Intriguingly, despite the sequence similarity and similar positions in the exosome structure occupied by EXOSC2 and EXOSC3, mutations in these subunits result in distinct diseases, with mutations in EXOSC2 causing SHRF and mutations in EXOSC3 causing Pontocerebellar Hypoplasia type 1b (PCH1b), a rare autosomal recessive neonatal/fetal neurodegenerative disease characterized by hypoplasia and atrophy of the cerebellar cortex, dentate nuclei, pontine nuclei and inferior olives. That mutation in core subunits of a seemingly universally required RNA exosome complex can result in distinct diseases reflects inherent complexity in the organization, function, and regulation of this fundamental machinery of post-transcriptional gene regulation. But our understanding of the mechanistic basis underlying these processes is very limited. We hypothesize that RNA exosome subunits are assembled into different subcomplexes with different RNA substrate engagements, and that these subcomplexes may function in a tissue or cell type-specific manner. To test this hypothesis, we propose to employ the recently developed proximity labeling using the engineered enzyme ascorbate peroxidase 2 (APEX2) to systematically identify proteins and RNAs in the immediate proximity of EXOSC2 in mammalian cell culture models, including iPSC-derived neuronal and muscle models, and in vivo Drosophila models. The functional involvement of newly identified factors in exosome biology and SHRF pathogenesis will be tested in Drosophila models. Successful execution of this project will not only lead to new knowledge on the composition, regulation, and tissue-specific requirement of the RNA exosome complex, but also shed light on the pathogenesis of RNA exosome-linked diseases, from SHRF, PCH, SMA and pulmonary fibrosis to cancer, diseases affecting multiple body systems. It is therefore expected that findings from this study will be applicable to the missions of multiple NIH Institutes or Centers (ICs), one of the stated Research Objectives of this R21 funding opportunity.

项目摘要 身材矮小、听力丧失、视网膜色素变性和特殊面容（SHRF）是一种罕见的常染色体隐性遗传病， 以身材矮小、短指（趾）畸形、面部特征畸形、听力和视力丧失为特征的疾病 损伤患者还表现出轻度智力残疾。SHRF是由纯合子或复合型 编码RNA外泌体复合物亚基的EXOSC 2基因中的杂合突变， 一种保守的多亚基核糖核酸溶解复合物，控制3 ′至5 ′的加工和降解， 所有真核细胞中的各种RNA。九个亚基（EXOSC 1 -9）形成一个催化惰性的核心， 两个核糖核酸酶亚基（EXOSC 10和Dis 3）的支架。EXOSC 2和EXOSC 3是S1和KH结构域 含有形成外泌体帽结构的RNA结合蛋白。有趣的是，尽管序列 EXOSC 2和EXOSC 3所占据的外泌体结构中的相似性和相似位置， 这些亚基导致不同的疾病，EXOSC 2突变引起SHRF，EXOSC 3突变引起SHRF， 导致桥小脑发育不全1b型（PCH 1b），一种罕见的常染色体隐性遗传新生儿/胎儿 以小脑皮质，齿状核， 脑桥核和下橄榄。似乎普遍需要的RNA的核心亚基的突变 外泌体复合物可以导致不同的疾病，反映了组织、功能和免疫系统的内在复杂性。 这一转录后基因调控的基本机制的调控。但我们对 这些过程的机械基础非常有限。我们假设RNA外泌体亚基是 组装成具有不同RNA底物接合的不同亚复合物，并且这些亚复合物 亚复合物可以以组织或细胞类型特异性的方式起作用。为了验证这一假设，我们建议 使用最近开发的使用工程酶抗坏血酸过氧化物酶2的邻近标记 （APEX 2）系统地鉴定哺乳动物中紧邻EXOSC 2的蛋白质和RNA。 细胞培养模型，包括iPSC衍生的神经元和肌肉模型，以及体内果蝇模型。的 新鉴定的因子在外泌体生物学和SHRF发病机制中的功能参与将在 果蝇模型。该项目的成功实施不仅会带来关于 RNA外泌体复合物的组成、调节和组织特异性要求，但也揭示了 RNA外泌体相关疾病的发病机制，从SHRF、PCH、SMA和肺纤维化到癌症， 影响多个身体系统的疾病。因此，预计这项研究的结果将 适用于多个NIH研究所或中心（IC）的任务， R21融资机会