Development of a GBA p.E326K associated Parkinsons disease and Dementia with Lewy body mouse model

GBA p.E326K 相关帕金森病和痴呆症路易体小鼠模型的开发

基本信息

批准号：
9807496
负责人：
LORRAINE N CLARK
金额：
$ 8.1万
依托单位：
COLUMBIA UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-09-15 至 2021-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9807496
关键词：
Affect Age of Onset Alleles Animals Behavioral Biochemical Bradykinesia Brain Ceramide glucosyltransferase Ceramides Clinical Clinical Trials Defect Development Disease Enzymes Functional disorder Future Gaucher Disease Generations Genes Genetic Models Glucose Glucosylceramides Goals Human Impaired cognition Knock-in Mouse Lead Lewy Bodies Lewy Body Dementia Link Lysosomes Metabolism Molecular Chaperones Motor Mus Mutation Neurodegenerative Disorders Neurologic Neurologic Symptoms Parkinson Disease Parkinson&apos s Dementia Pathogenesis Pathology Pathway interactions Penetrance Phenotype Play Point Mutation Proteins Residual state Rest Tremor Risk Risk Factors Role Severity of illness Sphingosine Therapeutic Therapeutic Uses Transgenes Transgenic Organisms Variant alpha synuclein cognitive function disease phenotype endoplasmic reticulum stress enzyme activity glucosylceramidase glucosylsphingosine inhibitor/antagonist loss of function macrophage mouse model mutant neuropathology non-motor symptom overexpression synuclein targeted treatment therapeutic development

项目摘要

Gaucher disease (GD), one of the most common autosomal recessive lysosomal storage disorders, is caused by mutations in the Glucocerebrosidase (GBA) gene. The enzyme encoded by GBA, Gcase1, catalyzes the conversion of glucosylceramide (GlcCer) to glucose and ceramide. The primary defect in GD is the accumulation of GlcCer in lysosomes and is seen most prominently in macrophages. We and others have shown that specific mutations in the GBA gene, in the heterozygous state, are a risk factor for Parkinson’s disease (PD) and dementia with Lewy bodies (DLB). Functional studies have demonstrated an interaction between -synuclein and GBA protein and mutant GBA proteins can cause an increase in -synuclein (SNCA) levels and lysosomal dysfunction. Among the GBA variants associated with PD, p.E326K is one of the most frequent. Interestingly, the GBA p.E326K variant is only involved in GD when it is found in the same allele (in cis) with other ‘severe’ type mutations (e.g. p.L444P) and contributes to GD severity by further reducing residual enzyme activity. Although biochemical observations have suggested that p.E326K is a ‘mild’ type loss of function variant, this reduction in activity is clearly not severe enough to lead to a GD phenotype. Understanding the mechanistic links between specific GBA mutations and PD is critical for developing targeted therapeutic approaches. Currently, it is unclear how the GBA p.E326K mutation contributes to a neurological phenotype and pathology in the brain. More recent studies suggest that ceramide metabolism and its metabolites play a central role in disease pathogenesis of GBA-associated PD and DLB. We hypothesize that the GBA p.E326K variant, contributes to disease by a mechanism involving an imbalance (increase) of other metabolites in the ceramide metabolism pathway namely Glucosylsphingosine (GlcSph) and Sphingosine (Sph) leading to -synuclein aggregation and ER stress. Currently, therapeutic approaches to treat GBA associated PD are limited to a glucosylceramide synthase inhibitor and a molecular chaperone, ambroxol hydrochloride, both of which are currently in clinical trials. Development of a mouse model for the most common GBA variant associated with PD, the GBA p.E326K variant, and determining the disease mechanism may open up new avenues for therapeutic development targeting ASAH1 or GBA2 in the ceramide pathway and could have a major impact on the field. The goal of this proposal is to develop and characterize a Gba p.E326K mouse model that can be used for therapeutic development in future studies. we propose two specific aims. Specific Aim 1 is to generate and characterize a Gba p.E326K mouse model of PD and DLB and Specific Aim 2 is to determine whether overexpression of the human A30P -synuclein (SNCA) transgene modifies penetrance in Gba p.E326K mice and affects age of onset and progression of neurological symptoms.

戈谢病（GD）是最常见的常染色体隐性遗传性溶酶体贮积症之一，由由葡萄糖脑苷脂酶 (GBA) 基因突变引起。GBA 编码的酶 Gcase1 催化葡萄糖神经酰胺 (GlcCer) 转化为葡萄糖和神经酰胺是 GD 的主要缺陷。 GlcCer 在溶酶体中的积累，在巨噬细胞中最为明显。研究表明，杂合状态下 GBA 基因的特定突变是帕金森病的危险因素功能研究表明，路易体疾病（PD）和痴呆症（DLB）之间存在相互作用。 α-突触核蛋白和 GBA 蛋白之间以及突变的 GBA 蛋白可导致 α-突触核蛋白 (SNCA) 增加在与 PD 相关的 GBA 变异中，p.E326K 是最常见的变异之一。通常，GBA p.E326K 变体仅在同一等位基因中发现时才参与 GD（在顺式）与其他“严重”型突变（例如 p.L444P），并通过进一步降低 GD 严重程度做出贡献尽管生化观察表明 p.E326K 是一种“轻度”类型的损失。对于功能变异，这种活性的降低显然不足以导致 GD 表型。了解特定 GBA 突变与 PD 之间的机制联系对于开发靶向药物至关重要目前，尚不清楚 GBA p.E326K 突变如何导致神经系统疾病。最近的研究表明，神经酰胺代谢及其在大脑中的表现型和病理学。代谢物在 GBA 相关 PD 和 DLB 的疾病发病机制中发挥着核心作用。 GBA p.E326K 变体通过涉及其他物质失衡（增加）的机制导致疾病神经酰胺代谢途径中的代谢物，即葡萄糖基鞘氨醇 (GlcSph) 和鞘氨醇 (Sph) 导致 α-突触核蛋白聚集和 ER 应激，目前治疗 GBA 的方法较多。相关的 PD 仅限于葡萄糖神经酰胺合酶抑制剂和分子伴侣氨溴索盐酸盐，这两种药物目前都处于临床试验阶段。与 PD 相关的常见 GBA 变异，GBA p.E326K 变异，并确定疾病机制可能为神经酰胺途径中针对 ASAH1 或 GBA2 的治疗开发开辟新途径并可能对该领域产生重大影响该提案的目标是开发和描述 GBA。我们提出了两种可用于未来研究中的治疗开发的 p.E326K 小鼠模型。具体目标 1 是生成 PD 和 DLB 的 GBa p.E326K 小鼠模型并对其进行表征。目标 2 是确定人 A30P α-突触核蛋白 (SNCA) 转基因的过度表达是否会改变 Gba p.E326K 小鼠的外显率并影响神经系统症状的发病年龄和进展。