The role of a-synuclein accumulation in lysosomal hydrolase trafficking and function

α-突触核蛋白积累在溶酶体水解酶运输和功能中的作用

基本信息

批准号：
10659253
负责人：
Joseph R Mazzulli
金额：
$ 61.85万
依托单位：
NORTHWESTERN UNIVERSITY AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-08-01 至 2027-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10659253
关键词：
Biogenesis Biological Biology Brain Cell Death Cell physiology Cells Clinic Data Dementia with Lewy Bodies Disease Documentation Endoplasmic Reticulum Enhancers Failure Foundations Functional disorder Funding Genetic study Glucose Glycolipids Glycosphingolipids Golgi Apparatus Health Hexosamines Human Hydrolase In Vitro Inclusion Bodies Induced pluripotent stem cell derived neurons Knowledge Lewy Bodies Link Lysosomes Membrane Fusion Methods Modeling Mus Mutation Nerve Degeneration Nervous System Neurons Parkinson Disease Pathogenesis Pathogenicity Pathology Pathway interactions Patients Phenotype Play Process Protein Biosynthesis Proteins Quality Control Role SNAP receptor Solubility Stress Structure System Testing Toxic effect Transducers Work age related neurodegeneration alpha synuclein clinical development efficacy testing endoplasmic reticulum stress genetic risk factor genetic variant glucosylceramidase glycosylation improved in vivo induced pluripotent stem cell link protein loss of function loss of function mutation misfolded protein mouse model neurotoxicity new therapeutic target novel novel therapeutic intervention posters prevent protein aggregation protein folding protein transport proteostasis response sensor small molecule sound synucleinopathy therapy development trafficking

项目摘要

Abstract The aggregation of a-Synuclein (a-syn) into insoluble fibrils plays a key role in the pathogenesis of Dementia with Lewy bodies (DLB), Parkinson’s disease (PD) and other synucleinopathies. Despite the documentation of a-synuclein as a component of Lewy body inclusions for over 25 years, there remains a significant knowledge gap in the mechanisms that causally link protein aggregates to neurodegeneration. Recent genetic studies have implicated the lysosomal degradation system into the pathogenesis of DLB and PD. Among the strongest genetic risk factors are loss-of-function mutations lysosomal β-glucocerebrosidase (GCase) encoded by GBA1, indicating that compromised lysosomal function may play a direct role in neurodegeneration. During our previous funding period, we found that a-syn aggregates are initiated inside lysosomes by interacting with glycosphingolipid substrates that accumulate upon loss of GCase. Once formed, these aggregates perturb multiple, essential branches of the proteostasis pathway, including the folding in the endoplasmic reticulum (ER) and post-ER trafficking at the cis-Golgi. This further augments a-syn aggregation, creating a self-propagating pathogenic cycle. The previous funding period uncovered novel mechanisms and biological targets that enhance the trafficking of hydrolases and lysosomal function. Here, we will build on our previous work to examine how a- syn aggregates perturb protein folding in the ER, N-linked glycosylation in the ER, and the downstream effect on lysosomal function. We will develop novel molecules to restore these key proteostasis pathways. Our studies will employ a combination of patient-derived PD iPSC-neuron cultures, synucleinopathy mouse models, and human brain. We previously found that a-syn accumulation in PD patient neurons induced ER fragmentation and concealed the cell’s ability to recognize misfolded proteins in the ER, resulting in aggregation of immature GCase. Since misfolded proteins in the ER are usually recognized by the unfolded protein response (UPR), in aim 1, we will examine the link between the UPR, GCase solubility, and trafficking to the lysosome. We will determine if triggering the UPR in PD can restore lysosomal function and reduce a-syn. In aim 2, we will test the hypothesis that reduced glucose flux and protein N-glycosylation of GCase and other hydrolases contributes to lysosomal depletion and dysfunction in PD. In aim 3, we will build upon our prior studies, which showed that lysosomal function can be rescued by enhancing the SNARE protein ykt6. We will test novel small molecule activators of the ykt6-lysosomal biogenesis pathway in vitro and in vivo. By studying basic biology mechanisms of protein trafficking, we have a unique opportunity to link essential cellular proteostasis pathways to disease pathogenesis. Our studies may impact the field by discovering novel pathogenic mechanisms, identifying new biological targets, and further develop therapies to enhance lysosomal biogenesis to restore proteostasis in PD and DLB.

抽象的 A-突触核蛋白（A-Syn）在不溶性原纤维中的聚集起着关键作用 Lewy身体（DLB），帕金森氏病（PD）和其他突触核酸的痴呆症。尽管有 a核蛋白作为路易体内夹杂物的组成部分已有25年以上的文档在发生的机制中，有明显的知识差距将蛋白质聚集物与神经退行性关系联系起来。最近的遗传研究已将溶酶体降解系统实施到DLB和PD的发病机理中。之中强大的遗传危险因素是功能丧失突变突变溶酶体β-葡萄糖酶酶（GCASE）由GBA1编码，表明受损的溶酶体功能可能在神经变性中起着直接的作用。在以前的资金期间，我们发现A-Syn聚集体是通过交互而在溶酶体内部启动的与糖脂底物相关的糖脂损失后，GCASE损失。一旦形成，这些聚合会干扰蛋白质病途径的多个必需分支，包括内质网中的折叠（ER）以及在顺式高尔基的贩运后。这进一步增强了A-Syn聚合，创造了自我传播致病周期。以前的资金期发现了增强的新型机制和生物学目标水解酶和溶酶体功能的运输。在这里，我们将基于以前的工作来研究A- Syn聚集体扰动蛋白在ER中折叠，N-连接的ER中的糖基化和下游效应在溶酶体功能上。我们将开发新的分子来恢复这些关键的蛋白质途径。我们的研究将采用患者来源的PD IPSC-Neuron培养物，突触核酸小鼠模型和人脑。我们以前发现，PD患者神经元中的A-Syn积累会诱导ER碎裂和隐藏了细胞在ER中识别错误折叠蛋白的能力，导致未成熟的聚集 GCASE。由于ER中错误折叠的蛋白通常通过未折叠的蛋白质反应（UPR）识别 AIM 1，我们将检查UPR，GCASE溶解度和贩运与溶酶体之间的联系。我们将确定在PD中触发UPR是否可以恢复溶酶体功能并减少A-Syn。在AIM 2中，我们将测试假设gcase和其他水解酶减少葡萄糖通量和蛋白质N-糖基化有助于 PD中的溶酶体耗竭和功能障碍。在AIM 3中，我们将基于先前的研究，这表明溶酶体功能可以通过增强SNARE蛋白YKT6挽救。我们将测试新颖的小分子 YKT6-溶菌体生物发生途径的活化剂在体外和体内。通过研究基本生物学机制在蛋白质运输中，我们有一个独特的机会将必需的细胞蛋白质量途径联系起来发病。我们的研究可能通过发现新的致病机制来影响该领域生物学靶标，并进一步发展疗法以增强溶酶体生物发生以恢复PD中的蛋白质抗体和DLB。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Reciprocal effects of alpha-synuclein aggregation and lysosomal homeostasis in synucleinopathy models.

DOI：
10.1186/s40035-023-00363-z
发表时间：
2023-06-13
期刊：
TRANSLATIONAL NEURODEGENERATION
影响因子：
12.6
作者：
Drobny, Alice;Boros, Fanni Annamaria;Balta, Denise;Huarcaya, Susy Prieto;Caylioglu, Deniz;Qazi, Niyeti;Vandrey, Julia;Schneider, Yanni;Dobert, Jan Philipp;Pitcairn, Caleb;Mazzulli, Joseph Robert;Zunke, Friederike
通讯作者：
Zunke, Friederike

Characterization of the complex formed by β-glucocerebrosidase and the lysosomal integral membrane protein type-2

DOI：
10.1073/pnas.1514005113
发表时间：
2016-04-05
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
影响因子：
11.1
作者：
Zunke, Friederike;Andresen, Lisa;Schwake, Michael
通讯作者：
Schwake, Michael

Detection of pathological alpha-synuclein aggregates in human iPSC-derived neurons and tissue.