Exploring the Pathogenic Mechanisms of Batten's disease MFSD8 mutations using patient iPSC derived neurons.

使用患者 iPSC 衍生的神经元探索巴顿病 MFSD8 突变的致病机制。

基本信息

批准号：
10467764
负责人：
Joseph R Mazzulli
金额：
$ 24万
依托单位：
NORTHWESTERN UNIVERSITY AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-04-01 至 2024-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10467764
关键词：
Adolescent Amino Acids Astrocytes Axon Biochemical Biological Assay Biological Markers Blindness Blood Brain CTSD gene Categories Cathepsins B Cell Death Cell Line Cells Ceroid Cessation of life Childhood Coculture Techniques Data Dementia Dendrites Disease Disease Progression Event Fibroblasts Foundations Frontotemporal Dementia Functional disorder Genes Genetic Genetic Diseases Heterozygote Histopathology Hydrolase In Vitro Induced pluripotent stem cell derived neurons Inherited Lead Lewy Body Dementia Link Lysosomal Storage Diseases Lysosomes Maintenance Mass Spectrum Analysis Membrane Proteins Modeling Mutation Nerve Degeneration Neurites Neurodegenerative Disorders Neuroglia Neurologic Dysfunctions Neurologic Symptoms Neuronal Ceroid-Lipofuscinosis Neurons PARK9 gene Parkinson Disease Pathogenicity Pathology Pathway interactions Patients Pharmacology Phenotype Point Mutation Population Proteins Proteome Proteomics Role Seizures Solubility Spielmeyer-Vogt Disease Stable Isotope Labeling Structure Techniques Toxic effect Toxin Variant Western Blotting Work age related age related neurodegeneration alpha synuclein extracellular falls glucosylceramidase induced pluripotent stem cell infancy inhibitor insight link protein lipopigments loss of function loss of function mutation neuronal survival neurotoxicity new therapeutic target novel novel therapeutics personalized medicine premature presynaptic protein aggregation proteostasis solute synucleinopathy

项目摘要

Mutations in the MFSD8 gene cause CLN7 Batten’s disease (BD), a rare neurodegenerative lysosomal storage disorder characterized by the accumulation of a lipopigment called ceroid in the brain. Furthermore, MFSD8 mutations were recently associated with frontotemporal dementia (FTD), and other BD-associated genes are linked to Parkinson’s disease (ATP13A2) and other subtypes of FTD (GRN, CTSD). CLN7 BD falls within a broader category of pediatric diseases called neuronal ceroid lipofuscinoses (NCL) that share common histopathology of ceroid accumulation in neurons and neurological symptoms including dementia, blindness, seizures, and premature death. The MFSD8 gene encodes the CLN7 protein, a membrane protein of unknown function that is localized to lysosomes. Mutations that cause CLN7 BD are loss of function and many of the known mutations result in premature stops or point mutations that destabilize the protein. Our previous studies in patient fibroblasts demonstrated that loss of CLN7 reduces lysosomal hydrolase activity, autophagic flux, and the accumulation of autofluorescent material. While these studies contributed to our understanding of how CLN7 leads to disease, the mechanisms that lead to neurodegeneration are not known. Furthermore, there are no studies done in relevant patient-derived neuronal models. Here, we propose to explore the mechanisms of neurotoxicity caused by CLN7 mutations, using a several iPSC-lines derived from distinct BD patients. Our preliminary data indicates that CLN7 BD lines can develop into cortical neurons in vitro, but demonstrate lysosomal phenotypes and reduced neurite extensions. In aim 1, we plan to use this established neuronal model to determine how loss of CLN7 influences the stability of the proteome and protein solubility to discover novel pathways and generate hypotheses for how cell death occurs in CLN7 BD. In aim 2, we will assess rescue mechanisms that aim to restore protein homeostasis in CLN7 neurons, as well as co-culturing wild-type astrocytes with CLN7-BD neurons to assess the role of glia cells in dementia. Since almost no mechanistic information is known about how CLN7 causes neurological dysfunction, our studies have the potential to uncover novel therapeutic pathways for CLN7 BD and other NCLs that share similar pathologies. Beyond NCLs, mutations in MFSD8 are associated with FTD, an age-related neurodegenerative disorder, and therefore our studies may be relevant to more common age-related neurodegeneration. Since there is accumulating evidence for lysosomal dysfunction common sporadic diseases including Parkinson’s disease and other synucleinopathies, our studies may have a broad impact on the field.

MFSD8基因中的突变引起CLN7 Batten氏病（BD），这是一种罕见的神经退行性溶酶体储存障碍，其特征是脂肪在大脑中被称为CERO。此外，MFSD8突变最近与额颞痴呆（FTD）相关，其他与BD相关的基因与帕金森氏病（ATP13A2）和FTD的其他亚型（GRN，CTSD）有关。 CLN7 BD属于更广泛的儿科疾病，称为神经元蛋白脂肪糖苷（NCL），这些疾病（NCL）共享神经元和神经系统症状的共同组织病理学，包括痴呆，失明，癫痫发作和早期死亡。 MFSD8基因编码CLN7蛋白，CLN7蛋白是一种局部与溶酶体的未知功能的膜蛋白。引起CLN7 BD的突变是功能的丧失，许多已知突变导致过早停止或点突变破坏蛋白质的稳定。我们先前对患者成纤维细胞的研究表明，CLN7的丧失会降低溶酶体水解酶活性，自噬通量和自动荧光材料的积累。尽管这些研究有助于我们对CLN7如何导致疾病的理解，但导致神经变性的机制尚不清楚。此外，在相关患者衍生的神经元模型中没有研究。在这里，我们建议使用来自不同BD患者的少数IPSC线引起的神经毒性机制。我们的初步数据表明，CLN7 BD系可以在体外发展成皮质神经元，但显示出溶酶体表型和降低的神经蛋白延伸。在AIM 1中，我们计划使用这种已建立的神经元模型来确定CLN7的损失如何影响蛋白质组和蛋白质溶解度的稳定性，以发现新型途径并为CLN7 BD中细胞死亡的方式产生假设。在AIM 2中，我们将评估旨在恢复CLN7神经元中蛋白质稳态的救援机制，以及与CLN7-BD神经元共同培养野生型星形胶质细胞来评估胶质细胞在痴呆症中的作用。由于几乎没有关于CLN7如何引起神经功能障碍的机械信息，因此我们的研究可能会发现CLN7 BD和其他具有相似病理的NCL的新型治疗途径。除了NCLS之外，MFSD8中的突变与与年龄相关的神经退行性疾病的FTD有关，因此我们的研究可能与更常见的与年龄相关的神经变性有关。由于有累积的证据表明溶酶体功能障碍常见的偶发性疾病在内，包括帕金森氏病和其他突触核苷病，我们的研究可能会对该领域产生广泛的影响。