Astrocyte-secreted proteins as modulators of neurodegeneration in Down Syndrome and Alzheimers Disease

星形胶质细胞分泌的蛋白质作为唐氏综合症和阿尔茨海默病神经变性的调节剂

• 批准号: 10644858
• 负责人: Ashley N Brandebura
• 金额: $ 12.42万
• 依托单位: SALK INSTITUTE FOR BIOLOGICAL STUDIES
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10644858
• 关键词: Acceleration; Address; Adult; Affect; Age; Age of Onset; Aging; Alzheimer' s Disease; Amyloid; Amyloid beta-Protein; Amyloid beta-Protein Precursor; Astrocytes; Autopsy; Behavioral; Biological; Biology; Biotin; Brain; California; Cells; Characteristics; Chromosome 21; Clinical; Compensation; Congenital chromosomal disease; Data; Data Set; Databases; Dementia; Dendrites; Dendritic Spines; Deposition; Disease; Disease Progression; Down Syndrome; Endoplasmic Reticulum; Event; Foundations; Future; Gene Dosage; Gene Proteins; Genetic; Genetic Transcription; Growth; Hippocampus; Human; Impaired cognition; In Vitro; Individual; Intellectual functioning disability; Investigation; Knockout Mice; Label; Laboratories; Length; Link; Literature; Live Birth; Location; Mass Spectrum Analysis; Mediating; Memory impairment; Mentors; Messenger RNA; Mining; Molecular; Mus; Mutation; Neonatal; Nerve Degeneration; Neurodevelopmental Disorder; Neurologist; Pathogenesis; Pathologic; Pathology; Patients; Peptide Fragments; Phenocopy; Phenotype; Population; Protein Databases; Protein Secretion; Proteins; Proteomics; Public Health; Reporting; Research; Research Personnel; Role; Senile Plaques; Series; Stains; Streptavidin; Synapses; Synapsins; System; Technology; Testing; Tissues; Training; Transcript; Trisomy; Universities; Vertebral column; Viral; Virus; Work; abeta accumulation; astrogliosis; career; cell type; comparison control; conditioned fear; density; differential expression; experimental study; hippocampal pyramidal neuron; in vivo; interest; knock-down; lifetime risk; mRNA Expression; mouse Ts65Dn; mouse model; neuropathology; novel; overexpression; pleiotrophin; single nucleus RNA-sequencing; spatial memory; therapeutic target

Project Summary/Abstract Down Syndrome (DS) is a neurodevelopmental disorder caused by trisomy of chromosome 21, and with age a majority of DS patients develop neuropathological hallmarks associated with Alzheimer’s Disease (AD), including amyloid plaque deposition and astrogliosis, as well as clinical dementia (cooccurrence of DS with AD is DS-AD). Amyloid precursor protein (APP) mutations are linked to AD, and DS patients have triplication of the APP gene, suggesting this as a contributing factor to the overlapping pathology. Research suggests astrocytes are regulators of both DS and AD disease progression. Astrocytes modulate synapses through the release of secreted proteins, and recent work suggests that astrocyte protein secretion is dysregulated in both DS and AD. The Allen lab identified >700 astrocyte-secreted proteins dysregulated in the Ts65Dn mouse model of DS at neonatal timepoints. Of interest, secretion of the pro-growth protein pleiotrophin (Ptn) was >4x down-regulated from Ts65Dn astrocytes, and subsequent investigations of Ptn knockout mice revealed that they phenocopy Ts65Dn mice in many aspects, including decreased dendrite length and spine density. Single nucleus RNA- Sequencing studies show that subsets of “disease-associated” astrocytes in AD down-regulate transcripts encoding for many pro-synaptogenic factors, including Ptn. The main hypotheses of this proposal are that: 1) a network of overlapping astrocyte-secreted proteins is altered in DS-AD and AD, and 2) decreased Ptn secretion from astrocytes contributes to disease progression in DS-AD and AD. This proposal takes an unbiased approach to characterize changes in the astrocyte secretome in DS-AD and AD mouse models, as well as a targeted approach to investigate the potential for Ptn to rescue neuropathological phenotypes. Aim 1/K99 utilizes biotin- mediated proximity labeling (an endoplasmic reticulum localized TurboID virus) to create novel datasets for the in vivo astrocyte-specific secretome in DS-AD and AD mouse models at early, middle and late stages of disease. This aim provides the investigator with extensive training in mass spectrometry technology and quantitative proteomics analysis. Aim 2/R00 employs viral-mediated Ptn overexpression in astrocytes to investigate if Ptn can rescue spine density, astrogliosis and spatial memory impairments in DS-AD and AD mouse models. Additionally, the investigator will utilize the astrocyte-specific secretome datasets from Aim 1 to investigate other protein candidates in their future laboratory. The mentoring team consists of Dr. Nicola Allen, a leader in astrocyte biology; Dr. Alan Saghatelian, who will provide expertise in quantitative proteomics; Dr. Jolene Diedrich, mass spectrometry core director; Dr. Nick Andrews, behavioral core director; and Dr. Douglas Galasko, a neurologist specializing in dementia and Associate Director of the Alzheimer’s Disease Research Center (ADRC) at the University of California San Diego (UCSD). The work will take place at the world class Salk Institute for Biological Studies and establish networking connections at the ADRC and UCSD, providing an essential foundation for Dr. Brandebura’s independent research career focused on astrocyte-secreted proteins in neurodegeneration.

项目总结/摘要 唐氏综合征（DS）是一种由21号染色体三体引起的神经发育障碍，随着年龄的增长， 大多数DS患者出现与阿尔茨海默病（AD）相关的神经病理学标志，包括 淀粉样斑块沉积和星形胶质细胞增生，以及临床痴呆（DS与AD共现为DS-AD）。 淀粉样前体蛋白（APP）突变与AD有关，DS患者具有APP基因的三倍， 表明这是重叠病理学的一个促成因素。研究表明星形胶质细胞 DS和AD疾病进展的调节剂。星形胶质细胞通过释放 分泌的蛋白质，最近的工作表明，星形胶质细胞蛋白质分泌失调，在DS和AD。 艾伦实验室在DS的Ts 65 Dn小鼠模型中鉴定了超过700种星形胶质细胞分泌的蛋白质， 新生儿时间点。感兴趣的是，促生长蛋白多效生长因子（Ptn）的分泌下调> 4倍。 从Ts 65 Dn星形胶质细胞，和随后的研究Ptn敲除小鼠显示，他们表型 Ts 65 Dn小鼠在许多方面，包括树突长度和棘密度减少。单核RNA- 测序研究表明，AD中“疾病相关”星形胶质细胞的亚群下调转录 编码许多促突触形成因子，包括Ptn。本建议的主要假设是：1） 在DS-AD和AD中，重叠的星形胶质细胞分泌的蛋白质的网络被改变，以及2）减少的Ptn分泌 导致DS-AD和AD的疾病进展。这项建议采取了不偏不倚的态度 以表征DS-AD和AD小鼠模型中星形胶质细胞分泌组的变化，以及靶向的 研究Ptn拯救神经病理表型的潜力的方法。Aim 1/K99利用生物素- 介导的邻近标记（一种内质网定位的TurboID病毒）为创建新的数据集 在疾病的早期、中期和晚期，在DS-AD和AD小鼠模型中的体内星形胶质细胞特异性分泌组。 这一目标为研究者提供了质谱技术和定量分析方面的广泛培训。 蛋白质组学分析Aim 2/R 00采用病毒介导的星形胶质细胞中Ptn过表达来研究Ptn是否 可以挽救DS-AD和AD小鼠模型中的脊柱密度、星形胶质细胞增生和空间记忆障碍。 此外，研究者将利用来自Aim 1的星形胶质细胞特异性分泌组数据集来研究其他肿瘤。 在未来的实验室里，指导小组由尼古拉艾伦博士组成，他是星形胶质细胞 生物学;艾伦·萨格特利安博士，他将提供定量蛋白质组学方面的专业知识;乔琳·迪德里奇博士，马萨诸塞州 光谱学核心主任;尼克·安德鲁斯博士，行为核心主任;道格拉斯·加拉斯科博士，神经学家 专门从事痴呆症和副主任阿尔茨海默病研究中心（ADRC）在 加州圣地亚哥大学（UCSD）。这项工作将在世界级的索尔克生物研究所进行， 在ADRC和UCSD研究和建立网络连接，为博士提供必要的基础。 Brandebura的独立研究生涯主要集中在神经退行性疾病中的星形胶质细胞分泌蛋白。