Poly(ADP-ribose)-dependent TDP-43 pathology in oxidative stress (R21)

氧化应激中聚 (ADP-核糖) 依赖性 TDP-43 病理学 (R21)

• 批准号: 10753095
• 负责人: Shaida A. Andrabi
• 金额: $ 40.84万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10753095
• 关键词: Acceleration; Address; Affect; Alzheimer' s Disease; Alzheimer' s disease related dementia; Amyotrophic Lateral Sclerosis; Area; Binding; Biochemical; Biological; Biological Assay; Cell Death; Cell Nucleus; Cells; Cessation of life; Cryoelectron Microscopy; Cytoplasm; Cytosol; DNA-Binding Proteins; Data; Defect; Dementia; Deuterium; Disease; Event; Exposure to; Frontotemporal Dementia; Hydrogen; Hydrogen Peroxide; Imaging Techniques; Impairment; Inclusion Bodies; Length; Ligation; Limbic System; Mass Spectrum Analysis; Mediating; Modeling; Molecular Conformation; Mus; Mutation; Nature; Neurodegenerative Disorders; Neurons; Nuclear; Nuclear Export; Nuclear Import; Nuclear Localization Signal; Nuclear Protein; Oxidative Stress; Oxidative Stress Induction; Pathologic; Pathologic Processes; Pathology; Pathway interactions; Physiological; Play; Poly Adenosine Diphosphate Ribose; Poly(ADP-ribose) Polymerase Inhibitor; Poly(ADP-ribose) Polymerases; Polymers; Property; Protein Export Pathway; Protein translocation; Proteins; Publishing; RNA Recognition Motif; Role; Signal Transduction; Signaling Molecule; Solubility; Stress; Structure; Temporal Lobe; Time; Toxic effect; Transactivation; Variant; biophysical properties; confocal imaging; conformational alteration; disease-causing mutation; exportin 1 protein; inhibitor; nervous system disorder; neuron loss; protein TDP-43; response; virtual

Abstract Frontotemporal dementia (FTD) is an Alzheimer-related dementia disease (ADRD) and involves nuclear egress and cytoplasmic Transactivation response DNA binding protein 43 (TDP-43). The mechanisms for pathological export of TDP-43 or its accumulation in the cytoplasm is not clearly defined. Although, studies on disease-causing mutations have revealed that defects in nuclear import may be in part responsible for TDP-43 accumulation in the cytosol as these mutations change the properties of the protein. However, it remains largely unclear how TDP-43 accumulates in the cytosol, as the majority of the TDP-43 dependent pathologies are sporadic. TDP-43 contains two RNA recognition motifs (RRMs), a nuclear export signal (NES), and a nuclear localization signal (NLS) in its N-terminus, and binds poly (ADP-ribose) polymer (PAR) via a PAR-binding motif embedded in its NLS. Studies have shown that PAR inhibitors can inhibit TDP-43 pathology, and binding of PAR to TDP-43 can change its biophysical characteristics in solution. Exportin 1 (XPO1) mediates the NES-dependent export of proteins from the nucleus. TDP-43 is a 43kDa protein that may not require XPO1-dependent export under basal conditions but our data indicates that under neuronal stress conditions TDP-43 egresses the nucleus via XPO-1 dependent export. We hypothesize that in disease conditions like FTD type ADRD and related diseases; PAR binds TDP-43 in the nucleus and facilitates its interaction with XPO-1, which subsequently enhances the egress of TDP-43 from the nucleus to cytosol. This proposal is supported our preliminary data that both PARP inhibitor BMN673 and XPO-1 inhibitor KPT- 185 inhibit the cytosolic accumulation of TDP-43 in neurons and TDP-43 and XPO1 interact following PARP activation. In this proposal, we plan to study the alterations in TDP-43 in mouse cortical neurons exposed to oxidative stress. Oxidative stress is a common pathological process mediating protein mislocalization, aggregation, and cell death in virtually all neurological disorders including FTD. Oxidative stress via H2O2 in cortical neurons mediates a robust TDP-43 cytosolic localization. Therefore, it is likely that pathophysiological mechanisms identified in the oxidative stress model in cortical neurons can closely overlap/mimic pathological mechanisms in FTD and other ADRD involving changes/mislocalization of TDP-43. We will use biochemical, cell biological and imaging techniques in combination with proximity ligation assays, CryoEM, and Hydrogen/Deuterium Exchange mass spectrometry to assess the PAR-dependent alteration in TDP-43 and its interaction with XPO-1 that leads to an increase in the release of TDP-43 from the nucleus and subsequent accumulation/aggregation in the cytoplasm. These studies will help in understanding the pathophysiological mechanisms of TDP-43 accumulation in FTD, ALS, and other ADRD/dementia related diseases involving TDP-43

摘要