Cell-type-specific contributions to cortical dysfunction in frontotemporal dementia

细胞类型特异性对额颞叶痴呆皮质功能障碍的影响

• 批准号: 10317335
• 负责人: Rita Marie Cowell
• 金额: $ 47.68万
• 依托单位: SOUTHERN RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2022-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10317335
• 关键词: Affect; Affinity Chromatography; Age; Alzheimer' s disease related dementia; Binding; Bioinformatics; Biological Assay; Brain; Buffers; C9ORF72; Calcium; Cell Culture Techniques; Cell Death; Cell physiology; Cells; Complex; Computer Assisted; Data; Data Set; Databases; Defect; Dementia; Disease Progression; Electrophysiology (science); Equilibrium; Frontotemporal Dementia; Frontotemporal Lobar Degenerations; Functional disorder; Future; Gene Expression; Gene Expression Profile; Gene Proteins; Genes; Genetic Transcription; Glutamates; Human; Impairment; Interneurons; Intervention; Knock-in; Knock-in Mouse; Lewy Body Dementia; Mediating; Modeling; Motor Cortex; Mus; Mutation; Nerve Degeneration; Neurons; Nuclear; Parvalbumins; Pathologic; Pathology; Pathway interactions; Patients; Pharmacology; Population; Prefrontal Cortex; Property; Protocols documentation; RNA; RNA Binding; RNA Recognition Motif; RNA Splicing; RNA metabolism; Reporting; Resolution; Ribosomes; Somatostatin; Source; Spliced Genes; TDP-43 aggregation; Tissue-Specific Gene Expression; Transcript; Translating; Work; age related; behavioral impairment; cell type; differential expression; excitatory neuron; experimental study; gain of function; gamma-Aminobutyric Acid; hippocampal pyramidal neuron; imaging study; in vivo; induced pluripotent stem cell; inhibitory neuron; loss of function; mouse model; mutant; neurotransmission; novel; overexpression; patch clamp; prevent; protein TDP-43; protein protein interaction

Frontotemporal dementia (FTD) is a debilitating, age-related neurodegenerative condition caused by frontotemporal lobar degeneration (FTLD), most often accompanied by the accumulation and/or dysfunction of the protein TDP-43 (FTLD-TDP). Aggregation of TDP-43, encoded by the TARDBP gene, occurs with or without concomitant mutations in TARDBP, suggesting that its accumulation represents a convergent mechanism underlying cortical vulnerability in FTD. The mechanisms underlying the detrimental effects of TDP-43 dysfunction are complex and likely involve both gain- and loss-of-function mechanisms, due to alterations in the intracellular compartmentalization and aggregation properties of TDP-43. Despite the availability of cell culture and mouse models of TDP-43 pathology, the precise mechanisms by which TARDBP mutations give rise to cortical dysfunction and cell loss in vivo are not clear. Recent imaging studies implicate a disruption in excitatory and inhibitory (E:I) balance in the cortex of patients with FTD, yet very little work has been done to explore the mechanisms by which this arises in vivo. Recent data generated using knockin and overexpression models of TDP-43 have revealed alterations in gene expression, function, and viability of cortical parvalbumin-expressing fast-spiking interneurons (PV-INs), cells which provide the main source of feed-forward GABAergic neurotransmission in the cortex and are critical for maintaining E:I balance. However, very little is known about the mechanisms underlying PV-IN vulnerability with Tardbp mutations in vivo and how PV-IN dysfunction contributes to pyramidal excitatory neuron function and loss. The experiments proposed in this application aim to identify the effects of TDP-43 mutation on PV-INs by assessing the PV-IN-specific transcriptional changes which occur during the progression of disease in Tardbp mutant knockin mice (Aim 1) and determining the impact of Tardbp mutations on PV-IN properties and cortical E:I balance with age (Aim 2). Differential gene expression and splicing profiles will be generated for PV-INs and compared to other neuron types using cell-type-specific translating ribosome purification protocols, with comparison to publicly available datasets of transcriptional changes in mouse and iPSC models of FTLD-TDP and other FTDs and TDP-43 RNA-binding assay databases. Computer-assisted modeling will be used to generate cell-type-specific protein-protein-interaction networks to identify convergent genes/proteins which could serve as targets for preventing cellular dysfunction. Electrophysiological approaches will explore the contributions of different cell types to the progression of cortical dysfunction, with comparison to a TDP-43 overexpression model to explore whether altered neuronal properties reflect a gain-of-function mechanism. These studies have the potential to reveal the mechanisms by which TDP-43 abnormalities influence cortical function and identify novel genes and/or pathways for promoting normal cortical function in patients with FTD.

额颞性痴呆(FTD)是一种衰弱的、与年龄相关的神经退行性疾病，由 额颞叶变性(FTLD)，最常伴有脑积聚和/或功能障碍 TDP-43蛋白(FTLD-TDP)。由TARDBP基因编码的TDP-43在有或没有TARDBP基因的情况下发生聚集 TARDBP的伴随突变，表明它的积累代表了一种收敛机制 FTD的潜在皮质脆弱性。TDP-43有害作用的潜在机制 功能障碍是复杂的，可能涉及获得和丧失功能的机制，由于 TDP-43的胞内区隔和聚集特性。尽管有了细胞培养技术 和TDP-43病理的小鼠模型，TARDBP突变导致 体内的皮质功能障碍和细胞丢失尚不清楚。 最近的影像研究表明患者大脑皮层兴奋性和抑制性(E：I)平衡被破坏 然而，对于FTD，人们在探索体内发生这种情况的机制方面所做的工作很少。最新数据 利用TDP-43的敲门和过表达模型生成的数据显示了基因表达的变化， 皮层小白蛋白表达的快速尖峰中间神经元(PV-INS)的功能和生存能力，这些细胞为 大脑皮质前馈GABA能神经传递的主要来源，对维持E：I至关重要 平衡。然而，人们对TardBP导致PV-IN漏洞的机制知之甚少 活体突变以及PV-IN功能障碍如何导致锥体兴奋性神经元功能和丧失。这个 本申请中提出的实验旨在通过评估TDP-43突变对PV-INS的影响来确定TDP-43突变对PV-IN的影响 TardBP突变体在疾病进展过程中发生的PV-IN特异性转录变化 Knockin小鼠(Aim 1)及其TardBP突变对PV-IN特性和皮质E：I的影响 与年龄保持平衡(目标2)。将为PV-ins和Pv-Ins生成差异基因表达和剪接图谱 与使用细胞类型特异性翻译核糖体纯化方案的其他神经元类型相比， FTLD-TDP小鼠和IPSC模型转录变化公开数据集的比较 以及其他FTDS和TDP-43 RNA结合分析数据库。将使用计算机辅助建模来 生成特定细胞类型的蛋白质-蛋白质-相互作用网络，以确定能够 作为预防细胞功能障碍的靶点。电生理方法将探索 不同细胞类型在皮质功能障碍进展中的作用与TDP-43的比较 过度表达模型，以探索神经元属性的改变是否反映了功能获得机制。 这些研究有可能揭示TDP-43异常影响皮质的机制。 并确定促进FTD患者正常皮质功能的新基因和/或途径。