Development and characterization of an AAV-based tool to functionally ablate astrocytic mitochondria in specific brain regions in vivo

项目摘要 星形胶质细胞是一组在大脑中具有多种作用的胶质细胞。它们延伸了精细的过程， 定位在突触和血管附近，从而局部调节突触的形成、消除和 功能，以及血脑屏障通透性。这一地方法规更广泛地影响了 大脑中更大的神经回路。来自不同脑区的星形胶质细胞显示出不同的形态学和 基因表达谱，这表明功能的区域特异性。神经元变性， 帕金森病（PD）和阿尔茨海默病（AD）等脑部疾病的特征，以及星形胶质细胞 故障被怀疑，但没有很好地表征机械。 星形胶质细胞中的线粒体最近已经成为具有强大功能的特化亚细胞器。 自发的Ca2+流能够响应神经递质激动剂，一个独特的功能蛋白质组 配置文件，和空间分离到胞体与过程方面的Ca2+通量和形态。 这些独特的特征使我们推测星形胶质细胞线粒体的异常在 在加速大脑神经退行性过程中的作用。然而，缺乏工具来功能性消融 线粒体选择性地存在于体内特定脑区的星形胶质细胞中是确定 星形胶质细胞线粒体功能障碍如何导致神经退行性变。具体来说，开发这样一个工具 将使一个机制的理解星形胶质细胞线粒体在PD和AD中的作用。这里我们 我建议开发和表征一种基于腺相关病毒（AAV）的工具， 在与PD和AD相关的两个脑区域，即纹状体和后扣带回中的星形胶质细胞线粒体 皮质，分别。此外，我们将研究细胞自主和非细胞自主的影响， 功能性消融星形胶质细胞线粒体对星形胶质细胞和神经元基因表达谱的影响 目的是将获得的知识应用于PD和AD的体内模型。

PROJECT ABSTRACT Astrocytes are a group of glial cells with multiple roles in the brain. They extend fine processes that localize near synapses and blood vessels and thus locally regulate synapse formation, elimination and function, as well as blood-brain-barrier permeability. This local regulation more broadly impacts on the function of larger neural circuits within the brain. Astrocytes from different brain regions show distinct morphological and gene expression profiles, which suggest regional specificity of function. Links between neuronal degeneration, distinctive of brain maladies such as Parkinson’s disease (PD) and Alzheimer’s disease (AD), and astrocytic malfunction are suspected but not well characterized mechanistically. Mitochondria in astrocytes have recently emerged as specialized subcellular organelles with robust spontaneous Ca2+ fluxes capable of responding to neurotransmitter agonists, a distinct functional proteomic profile, and spatial segregation into somata versus processes with regard to Ca2+ fluxes and morphology. These unique characteristics lead us to hypothesize that abnormalities in astrocytic mitochondria play a major role in accelerating neurodegenerative processes in the brain. However, the lack of tools to functionally ablate mitochondria selectively in astrocytes from specified brain regions in vivo is a major barrier towards defining how astrocytic mitochondrial dysfunction contributes to neurodegeneration. Specifically, developing such a tool would enable a mechanistic understanding of the role of astrocytic mitochondria in PD and AD. Here, we propose to develop and characterize an adeno-associated virus (AAV)-based tool to functionally ablate astrocytic mitochondria in two brain regions relevant to PD and AD, viz. the striatum and posterior cingulate cortex, respectively. In addition, we will examine the cell-autonomous and non-cell autonomous effects of functionally ablating astrocytic mitochondria on astrocytic and neuronal gene expression profiles with the future goal of applying the knowledge gained to in vivo models of PD and AD.