Chloride Homeostasis in Lysosomal Function and Parkinson's Disease

溶酶体功能和帕金森病中的氯稳态

• 批准号: 10515961
• 负责人: ZIXU MAO
• 金额: $ 60.46万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10515961
• 关键词: Affect; Albers-Schonberg disease; Animal Model; Animals; Anions; Automobile Driving; Autophagocytosis; Autophagosome; Autopsy; Binding; Biochemical; Biological Markers; Biological Process; Biology; Brain; Brain Diseases; CLC Gene; Cathepsin C; Cell physiology; Cells; Chloride Channels; Chloride Ion; Chlorides; Complex; Data; Degenerative Disorder; Degradation Pathway; Disease; Environmental Risk Factor; Event; Family; Functional disorder; GTP-Binding Protein alpha Subunits, Gs; Genes; Genetic; Genetic Determinism; Genetic study; Health; Homeostasis; Human; Hydrolase; Impairment; Induced pluripotent stem cell derived neurons; Intracellular Space; LRRK2 gene; Link; Lysosomal Storage Diseases; Lysosomes; Modeling; Molecular; Mus; Mutation; Nerve Degeneration; Neurodegenerative Disorders; Neurons; Organelles; Oxidative Stress; Parkinson Disease; Pathogenesis; Pathogenicity; Pathologic; Pathology; Pathway interactions; Patients; Play; Process; Proteins; Regulation; Reporting; Research; Rodent Model; Role; Signal Transduction; Site; Stress; Substantia nigra structure; Testing; base; design; detection of nutrient; dopaminergic neuron; experimental study; human model; induced pluripotent stem cell; innovation; member; mutant; nervous system disorder; new therapeutic target; pars compacta; response; targeted biomarker

Parkinson's disease (PD) is a progressive and degenerative disorder of the brain. It is pathologically characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta (SNc). The key events driving the pathogenesis in PD are not completely understood. The long-term objective of my research is to understand the molecular and cellular processes by which neurons respond to stress and how dysfunction of these responsive mechanisms contributes to neurodegenerative process. I propose to investigate a new molecular regulatory process of lysosomal chloride and its role in PD pathogenesis. Chloride ion is the most abundant anion in both extra- and intracellular spaces of animal cells. No longer regarded as an inert anion, chloride is found to play discrete roles in cells and its homeostasis needs to be tightly regulated at a subcellular organelle level. Lysosomal chloride is important for the function of acidic hydrolases. In addition to this general role, lysosomal chloride itself also has specific roles affecting lysosomal functions such as binding directly to cathepsin C to regulate its activity. Lysosomal chloride is mainly regulated by chloride channel 7 (CLC-7) in complex with its beta subunit Ostm-1. Loss of either protein severely comprises lysosomal chloride homeostasis, reduces lysosomal degradation capacity, and causes accumulation of lysosomal storage materials and autophagosomes, leading to diseases in human and rodent models including neuronal damages and degeneration. How CLC-7 is regulated remains largely unknown and no studies have ever reported its involvement in PD pathogenesis. We discovered unexpectedly a regulatory link between leucine-rich repeat kinase 2 (LRRK2), one of the most common genetic determinants associated with PD, and CLC-7. Our new preliminary data show a direct interaction between LRRK2 and CLC-7. This interaction is pathogenically enhanced by LRRK2 G2019S mutation and by oxidative stress, leading to aberrantly high level of lysosomal chloride and reduced lysosomal activities. We hypothesize that LRRK2 interacts with CLC-7 to modulate lysosomal chloride homeostasis and pathogenic mutant LRRK2G2019S dysregulates this process and impairs lysosomal functions. We propose to assess the molecular effects of LRRK2 on CLC-7 function in DA neurons derived from iPSCs of PD patients (aim I), assess the cellular effects of aberrant LRRK2-CLCL-7 interaction under genetic and oxidative stress on lysosomal functions in DA neurons derived from control and PD patient iPSCs (aim II); assess the molecular and cellular effects of LRRK2 on lysosomal CLC-7, chloride, and functions in animal models of PD (aim III), and assess the lysosomal LRRK2, CLC-7, and chloride in postmortem brains of PD patients (aim IV). The study will identify the key process that controls lysosomal chloride, establish its role in PD cytopathogenesis, and possibly reveal new therapeutic targets and biomarkers for the disease.

帕金森氏病（PD）是大脑的进行性和退化性疾病。它是病理 其特征是底虫nigra pars commacta（SNC）中多巴胺能神经元的丧失。钥匙 尚未完全了解驱动PD发病机理的事件。我研究的长期目标 是要了解神经元对压力响应以及功能障碍的分子和细胞过程 这些响应机制有助于神经退行性过程。我建议调查一个新的 溶酶体氯化物的分子调节过程及其在PD发病机理中的作用。氯离子最多 动物细胞的外部和细胞内空间中丰富的阴离子。不再被视为惰性阴离子， 发现氯化物在细胞中起离散的作用，其稳态需要在亚细胞上严格调节 细胞器级别。溶酶体氯化物对于酸性水解酶的功能很重要。除了这个将军 角色，溶酶体氯化物本身还具有影响溶酶体功能的特定作用，例如直接结合 组织蛋白酶C调节其活性。溶酶体氯化物主要受氯化物通道7（CLC-7）的调节 复杂及其beta亚基OSTM-1。两种蛋白质的损失严重包含溶酶体氯化物 稳态，降低溶酶体降解能力，并导致溶酶体储存的积累 材料和自噬体，导致人类和啮齿动物模型的疾病，包括神经元损害 和变性。 CLC-7的调节方式仍然很大程度上未知，并且没有任何研究报告 参与PD发病机理。我们意外地发现了富含亮氨酸的重复之间的调节联系 激酶2（LRRK2），与PD相关的最常见的遗传决定因素之一和CLC-7。我们的新 初步数据显示LRRK2和CLC-7之间的直接相互作用。这种相互作用在病原上是 通过LRRK2 G2019S突变和氧化应激增强，导致溶酶体的含量异常高 氯化物和降低的溶酶体活性。我们假设LRRK2与CLC-7相互作用以调节 溶酶体氯化物稳态和致病突变体LRRK2G2019S失调并损害 溶酶体功能。我们建议评估LRRK2对DA神经元中CLC-7功能的分子效应 源自PD患者的IPSC（AIM I），评估异常LRRK2-CLCL-7的细胞效应 在遗传和氧化应激下对源自溶酶体功能的氧化应激的相互作用 控制和PD患者IPSC（AIM II）；评估LRRK2对溶酶体的分子和细胞作用 CLC-7，氯化物和PD动物模型中的功能（AIM III），并评估溶酶体LRRK2，CLC-7和 PD患者的后大脑中氯化物（AIM IV）。该研究将确定控制的关键过程 溶酶体氯化物，确定其在PD细胞病发生中的作用，并可能揭示新的治疗靶标和 该疾病的生物标志物。