Functional assessment of pathological α-syn and Aβ species in LBD

LBD 中病理 α-syn 和 Aβ 物种的功能评估

• 批准号: 10686906
• 负责人: Pamela J McLean
• 金额: $ 57.57万
• 依托单位: MAYO CLINIC JACKSONVILLE
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-20 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10686906
• 关键词: Alleles; Alzheimer' s Disease; Amyloid beta-Protein; Autophagocytosis; Autopsy; Biochemical; Biological; Biological Assay; Brain; Brain region; Cell model; Cells; Characteristics; Clinical; Cognitive deficits; Collaborations; Complement; Complex; Dementia; Dementia with Lewy Bodies; Development; Diagnostic; Disease; Endosomes; Enzymes; Genetic; Genetic Risk; Genetic Variation; Health; Human; Immunoassay; Impairment; Individual; Induced pluripotent stem cell derived neurons; Knowledge; Lewy Bodies; Lewy Body Dementia; Lipids; Lysosomes; Measures; Membrane; Methods; Molecular Conformation; Mutation; Neurons; Parkinson Disease; Parkinson' s Dementia; Pathologic; Pathway interactions; Patients; Positioning Attribute; Process; Proteins; Proteomics; Reporter; Research Personnel; Scanning; Senile Plaques; Slide; Structure; Subcellular Fractions; System; Tissues; Toxic effect; Validation; abeta accumulation; alpha synuclein; arm; beta pleated sheet; brain tissue; dementia risk; genetic risk factor; glucosylceramidase; in vivo; lipidomics; motor deficit; motor symptom; neuropathology; neurotoxic; novel; phosphoneuroprotein 14; prion-like; protein structure; response; single molecule; structural determinants; superresolution microscopy; synergism; transcriptomics

ABSTRACT Elucidation of underlying disease mechanisms in Lewy body dementia requires the systematic characterization of disease-specific changes in LBD brain tissue. The combination of dementia and motor symptoms at the clinical level is reflected in the neuropathology by the accumulation of alpha-synuclein (α-syn) in Lewy bodies and beta-amyloid (Aβ) in amyloid plaques. Both Aβ and α-syn are capable of aggregating into oligomers, fibrils, and beta sheets, but the aggregates that form are extremely heterogeneous in terms of both structure and function. The identification of which specific subspecies of the proteins are neurotoxic or support aggregation is poorly understood and as a result development of diagnostics and treatments that depend on knowledge of protein structure has been slow. Recent studies have suggested a ”seeded” or “prion-like” propagation for both α-syn and Aβ, indicating that abnormal conformations may ‘spread’ from diseased to healthy cells. While synthetic seeds of α-syn and Aβ confer toxicity in cells through various mechanisms, it is well known that the exact method of preparing these species influences their bioactivity to a high degree. Herein we take the next important step to analyze the actual subspecies from post-mortem brains, to define and compare aggregates, and identify mechanisms of toxicity and spreading underlying the selective regional vulnerabilities. We will extract soluble and insoluble α-syn and Aβ species from neuropathologically confirmed LBD brains with or without genetic LBD risk factors for structural and functional characterization. We will assess load and distribution of α-syn and Aβ subspecies and will detail their characteristics including size, structure and self- templating capabilities (Aim 1). The critical involvement of autophagy-lysosomal pathways in LBD is emphasized by the underlying genetic risks for LBD. Besides mutations in glucocerebrosidase (GBA) that interfere with lysosomal functions, it is well established that individuals with the APOE ϵ4 allele have a 6-fold greater risk for DLB. We will assess alterations in lysosome function in LBD brain and determine their response and contribution to processing, aggregation, and toxicity of α-syn and Aβ subspecies (Aim 2). We will use patients’ iPSC-derived neurons with different genetic risk factors to functionally validate the contribution to aggregation, toxicity and spreading of α-syn and Aβ (Aim 3). The expertise of this group of investigators synergizes to identify differences in structure and function of subspecies, to investigate mechanisms of aggregation and toxicity, and to unravel the contributions of the genetic variations and alterations in selective autophagy pathways to regional vulnerabilities. This puts us in a unique position to complement the studies of Projects 1, 2, and 3 of this CWOW at multiple levels and towards the full characterization of α-syn and Aβ subspecies.

摘要