Calpain cleavage of α-synuclein and T-cell reactivity in Parkinson’s disease

帕金森病中α-突触核蛋白的钙蛋白酶裂解和 T 细胞反应性

• 批准号: 10042307
• 负责人: NAREN L BANIK
• 金额: $ 41.11万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-15 至 2024-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10042307
• 关键词: Antigen Presentation; Asses; Attenuated; Autopsy; B-Lymphocytes; BCL2 gene; Biological Markers; Bone Marrow; Brain; CD4 Positive T Lymphocytes; Calcium; Calpain; Caspase; Cell Death; Cells; Cytoprotection; Data; Development; Disease; Disease Progression; Dopaminergic Cell; Flow Cytometry; Generations; Goals; Human; Immunodeficient Mouse; Immunohistochemistry; In Vitro; Infiltration; Inflammation; Inflammatory; Knock-out; Knockout Mice; Lead; Levodopa; Link; Mediating; Microglia; Movement Disorders; Mus; Nature; Nerve Degeneration; Neurodegenerative Disorders; Neuroglia; Neurons; Parkinson Disease; Pathogenicity; Patients; Peripheral; Pharmacology; Plasma; Play; Process; Production; Protein Isoforms; Rag1 Mouse; Research; Role; Small Interfering RNA; Spinal Cord; Substantia nigra structure; T cell response; T-Cell Activation; T-Lymphocyte; TdT-Mediated dUTP Nick End Labeling Assay; Testing; Tissues; Western Blotting; alpha synuclein; attenuation; calpain inhibitor; chemokine; cytokine; dopaminergic neuron; functional outcomes; improved; improved outcome; inhibitor/antagonist; knock-down; macrophage; migration; mouse model; neuron loss; neuronal survival; novel strategies; novel therapeutics; survival outcome; synuclein

Summary Parkinson's disease (PD) is a debilitating progressive degenerative movement disorder associated with loss of dopaminergic (DA) neurons in the substantia nigra (SN) along with the accumulation of α-synuclein (α-syn) in the brain, activation of microglia, production of inflammatory cytokines/chemokines, infiltration of CD4+ T-cells, and neurodegeneration. The most potent therapy, L-dopa, does not block disease progression, and the mechanism of the progressive nature is unclear. Calpain, a cysteine protease regulated by calcium, plays a pivotal role in SN and SC (spinal cord) degeneration in PD, and its role in α-syn aggregation, activation of microglia, T cells and their migration indicate calpain to be crucial in promoting the inflammatory process and disease progression. While calpain-1 cleavage of α-syn promotes synuclein aggregation in PD-like diseases, the precise involvement of the two major calpain isoforms, calpain-1 and calpain-2, in α-syn presentation to CD4+ T-cells remains unknown. Preliminary studies here identified a subtype of CD4+ T cells in MPTP mice, which was abolished by calpain inhibitor, suggesting that activation of calpain and CD4+ T cells may play critical roles in the inflammatory process and disease progression in PD. Preliminary data also suggest that siRNA-mediated knockdown of calpain-2 diminishes antigen presentation by human B-cells and inhibits activation of CD4+ T cells. Thus, we hypothesize that activation of distinct calpain isoforms may favor expansion of a subtype of α-syn-reactive CD4+ T cells in PD-like disease. We also hypothesize that calpain inhibition may attenuate α-syn aggregation and expansion of inflammatory T cells, reduce inflammation and support neuronal survival and improved outcome in PD patients. Two specific aims are proposed to test the hypothesis: (Aim 1) To investigate whether activation of calpain-1 or calpain-2 is linked with microglial presentation of α-syn to CD4+ T cells resulting in disease progression and neurodegeneration in PD-like disease in mice. (Aim 2) To determine whether inhibition of calpain-2 reduces microglial presentation of α-syn and generation of pathogenic CD4+ T cells, attenuating disease progression in mouse models of PD. The goal of this study is to investigate the role of calpain-1 and calpain-2 in generating α-syn-reactive pathogenic CD4+ T cells, and whether a subpopulation of CD4+ T cells from MPTP mice can induce PD-like disease in immunodeficient mice. Studies are planned to determine whether deletion of calpain-1 attenuates α-syn aggregation and expansion of CD4+ T cells using calpain-1 knockout (KO) mice. In addition, the role of calpain-2 inhibitor will be assessed in the study of alteration of inflammatory CD4+ T cell response and production of cytokines/chemokines in calpain-1 KO mice. Testing the effects of distinct calpain isoforms in the generation of α-syn-reactive pathogenic T cells and induction neuronal death and degeneration may lead to development of a novel approach for treating PD as well as other neurodegenerative disorders.

总结