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.

帕金森病（PD）是一种进行性和退行性大脑疾病。这是病理性的