Mechanism and importance of innate immune activation in a Drosophila GBA mutant model of Parkinson's disease

帕金森病果蝇 GBA 突变模型中先天免疫激活的机制和重要性

基本信息

批准号：
10259742
负责人：
Leo J Pallanck
金额：
$ 19.44万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-09-10 至 2023-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10259742
关键词：
Address Autophagocytosis Brain Ceramides DIF factor Data Dementia with Lewy Bodies Development Disease Disease model Drosophila genus Enzymes Exhibits Foundations Gaucher Disease Gene Expression Genes Genetic Glucose Glucosylceramides Glycosphingolipids Goals Immune Immune response Immunologic Factors Impairment Infection Inflammation Inflammatory Innate Immune Response Innate Immune System Lead Lewy Body Dementia Lipids Locomotion Longevity Measures Mediating Medical Membrane Modeling Molecular Movement Disorders Mutation Nerve Degeneration Neurodegenerative Disorders Orthologous Gene Parkinson Disease Pathogenesis Pathogenicity Pathway interactions Pattern Phenotype Process Production Proteins Proteomics Publishing RNA Interference Reporting Research Proposals Risk Factors Sphingolipids Testing Tissues Transcript Ubiquitin Work antimicrobial peptide dietary manipulation disease-causing mutation experimental study extracellular vesicles fly genetic association genetic manipulation glucosylceramidase immune activation immunogenic innate immune pathways knock-down lipidomics mutant neuroinflammation novel pathogen protein aggregation protein degradation therapy development transcriptome sequencing unpublished works vesicular release

项目摘要

ABSTRACT: Mutations in the glucosylceramidase beta (GBA) gene cause the lysosomal lipid storage disorder Gaucher’s disease and are the most frequent genetic association with Parkinson’s disease and Lewy body dementia. GBA encodes glucocerebrosidase, a lysosomal enzyme that catalyzes the breakdown of the sphingolipid glucosylceramide to ceramide and glucose. To explore the mechanism by which mutations in GBA predispose to these diseases, we created a Drosophila model of glucocerebrosidase deficiency by inactivating the Drosophila GBA ortholog, Gba1b. Gba1b mutants recapitulate many of the features of these diseases, including shortened lifespan, locomotor impairment, accumulation of glucosylceramide, protein aggregation in brain and other tissues, and neurodegeneration. In recently published work, we reported the results of a proteomic study of Drosophila Gba1b mutants that revealed dramatic alterations in the abundance and turnover of extracellular vesicle (EV) proteins. Our experiments also demonstrated that these proteomic findings reflected actual changes in the composition of EVs, and that genetic perturbations targeting factors involved in the production of EVs suppressed a Gba1b mutant phenotype. In more recent unpublished work, we used RNA-Seq to compare transcript abundance in Gba1b mutants and controls. This study revealed a profound induction of the innate immune response pathway in Gba1b mutants. This induction was specific to Gba1b mutants and was further corroborated in our proteomic data, and RNAi-mediated knockdown of an innate immune pathway component partially suppressed the brain protein aggregation phenotype of Gba1b mutants. From these and other findings, we hypothesize that the production of glucosylceramide-enriched EVs by Gba1b mutants triggers an innate immune response because these EVs resemble the glucosylceramide-enriched EVs released by pathogens during infection. We further hypothesize that this innate immune response accounts for the phenotypes of Gba1b mutants. We propose two aims to address these hypotheses; the first will investigate the mechanism of immune activation, and the second will investigate the importance of immune activation to Gba1b mutant pathogenesis. Thus, the primary goal of our research proposal is to provide a foundation for further mechanistic work by asking the two most fundamental questions raised by our preliminary findings: how does innate immune activation occur in Gba1b mutants, and is it important to their phenotypes? Given the increasing evidence for neuroinflammation in neurodegenerative disorders, including those caused by GBA mutations, we anticipate that our work will have broad medical significance.

抽象的：葡萄糖基酰胺酶β（GBA）基因的突变导致溶酶体脂质储存障碍Gaucher的疾病，是与帕金森氏病和路易人身体痴呆症最常见的遗传关联。 GBA编码葡萄糖脑苷酶，一种溶酶体酶，可催化鞘脂的分解葡萄糖基酰胺至神经酰胺和葡萄糖。探索GBA突变易感性的机制对于这些疾病，我们通过失活而创建了葡萄糖脑苷酶缺乏症的果蝇模型果蝇GBA直系同源物，GBA1b。 GBA1b突变体概括了这些疾病的许多特征，包括寿命缩短，运动障碍，葡萄糖基酰胺的积累，蛋白质聚集在大脑和其他组织以及神经退行性中。在最近发表的工作中，我们报告了果蝇GBA1b突变体的蛋白质组学研究揭示了丰度和细胞外囊泡（EV）蛋白的周转率。我们的实验还表明这些蛋白质组学发现反映了电动汽车组成的实际变化，以及遗传扰动靶向因素参与电动汽车的产生抑制了GBA1b突变表型。在最近的未发表的工作中，我们使用RNA-Seq比较了GBA1B突变体和对照组中的转录物丰度。这项研究表明 GBA1b突变体中先天免疫反应途径的深刻诱导。这种诱导是特定于 GBA1b突变体，并在我们的蛋白质组学数据中进一步证实，RNAi介导的敲低先天免疫途径部分部分抑制了GBA1b的脑蛋白聚集表突变体。从这些和其他发现中，我们假设富含葡萄糖酰胺的产生 GBA1b突变体的电动汽车触发了先天免疫反应，因为这些EV类似于病原体在感染过程中释放的富含葡萄糖酰胺的电动汽车。我们进一步假设这是先天免疫反应解释了GBA1b突变体的表型。我们提出了两个目的来解决这些假设；第一个将研究免疫激活的机制，第二个将研究免疫激活对GBA1B突变发病机理的重要性。那是我们的研究建议是通过询问两个人，为进一步的机械工作提供基础我们的初步发现提出的基本问题：GBA1b中的先天免疫激活如何发生突变体对他们的表型重要吗？考虑到越来越多的神经炎症的证据神经退行性疾病，包括由GBA突变引起的疾病，我们预计我们的工作将有广泛的医学意义。