Elucidating the Biological Differences Between Distinct Fibrillar and Non-Fibrillar Alpha-Synuclein Inclusions in Human Stem-Cell Models

阐明人类干细胞模型中不同纤维状和非纤维状 α-突触核蛋白内含物之间的生物学差异

• 批准号: 10622480
• 负责人: Vikram Khurana
• 金额: $ 78.99万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10622480
• 关键词: Affect; Affinity; Alzheimer' s Disease; Alzheimer' s disease related dementia; Amyloid; Amyloid beta-Protein; Amyloid fibers; Autopsy; Biochemical; Biological; Brain; Cell Line; Cell model; Cells; Ceramides; Characteristics; Circular Dichroism Spectroscopy; Data; Dementia with Lewy Bodies; Development; Diffuse; Disease; Disparate; Electron Microscopy; Equation; Fluorescence; Future; Genetic study; Glucosylceramides; Goals; Grant; Heterozygote; Homeostasis; Human; Human Genetics; Image; Immunofluorescence Microscopy; Impaired cognition; In Vitro; Induced pluripotent stem cell derived neurons; Intervention; Knock-in; Knock-out; Lead; Lesion; Lewy Bodies; Lewy body pathology; Lipids; Membrane; Membrane Lipids; Membrane Proteins; Modeling; Morphology; Multiple System Atrophy; Mutation; Nerve Degeneration; Neuroglia; Neurons; Nuclear Magnetic Resonance; Oligodendroglia; Parkinson' s Dementia; Pathogenicity; Pathology; Pathway interactions; Patients; Pattern; Periodicity; Phosphorylation; Physiological; Proteins; Proteolysis; Reporter; Saturated Fatty Acids; Series; Side; Sphingolipids; Stearoyl-CoA Desaturase; Synaptic Vesicles; System; Testing; Toxic effect; Transgenic Mice; Transgenic Organisms; Vesicle; Work; alpha synuclein; amyloid fibril formation; amyloid formation; brain cell; brain tissue; cell type; cerebral atrophy; conformer; dopaminergic neuron; experimental study; genetic manipulation; glucosylceramidase; human stem cells; in vitro Assay; in vivo; induced pluripotent stem cell; interest; kindred; mimetics; misfolded protein; mouse model; pharmacologic; pre-formed fibril; protein aggregation; serial imaging; stem cell model; synucleinopathy; tau Proteins; tau-1; trafficking; validation studies

Summary  Alzheimer’s  disease  (AD)  and  AD  related  dementias  (ADRD)  are  unpreventable,  incurable  and  remain  poorly  understood. Their hallmark pathology consists of misfolded proteins in characteristic “inclusions” within subsets  of neurons and glial cells of the brain. Misfolding of the membrane-­associated protein α-­synuclein (αS) is central  to ADRD. Inclusions rich in αS in cortical and dopaminergic (DA) neurons are the hallmark lesions of dementia  with Lewy bodies (DLB) and Parkinson disease with dementia (PDD). But αS inclusions are also found in >50%  of  AD  cases,  correlating  with  cognitive  decline  and  frequently  colocalizing  with  tau  pathology.  αS  pathology  is  strikingly  heterogeneous  and  poorly  understood.  Common  αS  pathology  comprises  vesicle-­rich  “pale  bodies”  (PBs),  amyloid-­rich  Lewy  bodies  (LBs),  or  combinations  of  these.    PBs  have  indeed  been  discussed  as  precursors  of  LBs,  but  what  gives  rise  to  PBs  and  how  they  may  convert  into  LBs  remains  enigmatic.  The  ultrastructural  features  of  PBs  and  LBs  parallel  enormous  interest  in  the  field  in  both  amyloid  and  vesicle-­ trafficking pathologies in PD. In experimental settings, the seeding of neurons with pre-­formed fibrils leads to LB-­ like  amyloid aggregates.  These  aggregates  can  under  certain  conditions  spread and  self-­template  in adjacent  cells. Different amyloid fiber conformers (“strains”) lead to different patterns of neurodegeneration, with differing  levels  of  phosphorylated  αS  and  tau.  Human  genetic  studies  have  repeatedly  implicated  perturbed  vesicle  trafficking and (membrane) lipid homeostasis as a fundamental and unifying feature in disparate forms of ADRD.  We  hypothesize  that  altered  cellular,  and  especially  lipid,  microenvironments  can trigger  αS  amyloid  formation  and the development of different strains and pathologies. An increasing body of evidence, including work from  our  groups,  indeed  suggests  that  αS  toxicity  and  aggregation  can  be  modulated  by  altering  cellular  fatty  acid  (FA) saturation or sphingolipid (SL) composition through manipulation of glucocerebrosidase (GBA) and stearoyl-­ coA  desaturase  (SCD),  respectively.  We  propose  to  dissect  the  influence  of  these  pathways  on  PB  and  LB  formation  and  transition  in  the  most  disease-­relevant  patient-­derived  induced  pluripotent  stem  cell  (iPSC)  models.  Importantly,  we  will  employ  patient  brain-­derived  “seed”  as  the  most  relevant  trigger  for  neuronal  αS  aggregation. The use of both patient-­specific cell types and misfolded protein conformers will allow us to capture  “in  the  dish”  both sides  of  the  toxic  equation  in  neurodegeneration.  We  recognize  the  importance,  but  also  the  limitations,  of  postmortem  end-­stage  pathology  in  delineating  disease  mechanisms,  and  propose  to  establish  cross-­correlation between in vitro assays, human induced pluripotent stem cell (iPSC) models and postmortem  brain tissue. We will focus on iPSCs derived from patients with familial and sporadic synucleinopathies that are  matched to postmortem brain, including cases with concomitant levels of AD (β-­amyloid and tau) pathology. Our  approaches not only promise to shed light on the formation and consequences of amyloid strains in ADRD, but  will also point at potential interventions centered around the transient interaction of αS with lipid membranes.

总结