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

• 批准号: 10011905
• 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
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-15 至 2022-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10011905
• 关键词: Affect; Age of Onset; Alleles; Animals; 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 Body Dementia; Lewy body pathology; Link; Lysosomes; Metabolism; Molecular Chaperones; Motor; Mus; Mutation; Neurodegenerative Disorders; Neurologic; Neurologic Symptoms; Parkinson Disease; Parkinson' 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; behavioral phenotyping; 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; targeted treatment; therapeutic development

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 α-synuclein and GBA protein and mutant GBA proteins can cause an increase in α-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 α-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 α-synuclein (SNCA) transgene modifies penetrance in Gba p.E326K mice and affects age of onset and progression of neurological symptoms.

Gaucher病（GD）是最常见的常染色体隐性溶酶体储存障碍之一。 通过葡萄糖脑酶酶（GBA）基因的突变。由GBA编码的酶GCASE1催化 葡萄糖基酰胺（GLCCER）转化为葡萄糖和神经酰胺。 GD中的主要缺陷是 GLCCER在溶酶体中的积累，在巨噬细胞中最为突出。我们和其他人有 表明在杂合状态下，GBA基因中的特定突变是帕金森氏症的危险因素 疾病（PD）和Lewy身体（DLB）的痴呆症。功能研究表明相互作用 α-突触核蛋白和GBA蛋白和突变GBA蛋白之间会导致α-突触核蛋白（SNCA）增加 水平和溶酶体功能障碍。在与PD相关的GBA变体中，P.E326K是最多的GBA变体之一。 频繁地。有趣的是，GBA P.E326K变体仅在同一等位基因中发现时才参与GD（在 顺式）具有其他“严重”型突变（例如P.L444p），并通过进一步降低而导致GD严重性 残留酶活性。尽管生化观察结果表明P.E326K是“轻度”型损失 在功能变异中，这种活性的减少显然不够严重，无法导致GD表型。 了解特定GBA突变与PD之间的机械联系对于开发目标至关重要 治疗方法。目前，目前尚不清楚GBA P.E326K突变如何促进神经系统 大脑中的表型和病理。最近的研究表明，神经酰胺代谢及其 代谢物在与GBA相关的PD和DLB的疾病发病机理中起着核心作用。我们假设这一点 GBA P.E326K变体通过一种机制导致疾病，涉及其他不平衡（增加） 神经酰胺代谢途径中的代谢产物，即葡萄糖基肾上腺素（GLCSPH）和鞘氨酸 （SPH）导致α-突触核蛋白聚集和ER应激。目前，治疗GBA的治疗方法 相关的PD仅限于葡萄糖基酰胺合酶抑制剂和分子伴侣，Ambroxol 盐酸盐目前正在临床试验中。最多开发鼠标模型 与PD相关的常见GBA变体，GBA P.E326K变体并确定疾病机制 可以为瞄准神经酰胺途径中的ASAH1或GBA2的治疗开发的新途径 并可能对该领域产生重大影响。该提议的目的是开发和表征GBA P.E326K小鼠模型，可用于未来的研究中用于热发育。我们提出了两个特定的 目标。特定目的1是生成和表征PD和DLB的GBA P.E326K小鼠模型以及特定 AIM 2是确定人A30Pα-突触核蛋白（SNCA）的过表达是否转换修饰符 GBA P.E326K小鼠的外观，会影响神经系统符号的发作年龄和进展。