Genetic Analysis of Glia-to-Neuron Communication

描述（由申请人提供）：尽管研究了“胶质传递”1、2，并表明星形胶质细胞可以调节哺乳动物模型中神经元的兴奋性和行为3、4，但关于成人大脑中胶质细胞与神经元通信的重要性仍存在争议。例如，有些人质疑神经胶质细胞Ca 2+依赖性机制在神经元调节中的重要性5-7。此外，尽管某些研究表明它涉及囊泡胞吐2，但对调节胶质递质释放的机制仍知之甚少。在这个应用中，我们提出了公正的分子遗传学的方法来确定神经胶质细胞和神经元的因素，神经胶质细胞到神经元的通信至关重要。我们以前表明，消除果蝇胶质细胞特异性因子称为乌木基因抑制多巴胺转运蛋白（DAT）突变体8的多动表型，表明神经胶质细胞到神经元的通信在调节活动水平的作用。在最近发表的研究中，我们已经证明，成年果蝇神经胶质细胞可以生理调节运动活动和昼夜节律9。我们的研究还证明了钙离子依赖机制和果蝇星形胶质细胞样神经胶质细胞在调节运动活动9中的关键作用。 在这个R21应用程序中，我们提出的研究，以确定细胞信号传导机制和细胞内通路，是重要的胶质细胞到神经元通信在成年动物。果蝇是用于此类研究的极好模型，因为成年脑的神经胶质类已被很好地表征10-12，并且一类与哺乳动物星形胶质细胞具有发育、形态和分子相似性11，13，14。我们的研究将利用多种条件扰动方法，这些方法是细胞类型特异性的和可逆的，以确定介导神经元和行为的胶质调制的新的、保守的因子和细胞内通路。目的1将利用我们最近开发的果蝇品系和翻译谱分析方法来鉴定神经元因子和神经胶质信号调节的分子通路。aim 2将使用行为遗传策略来定义神经胶质细胞信号传导机制，这对神经元调节很重要。这一提议代表了第一次广泛的神经元蛋白质组学的变化，发生神经胶质信号的结果研究。它也代表了介导成年神经元调制的神经胶质机制的第一个遗传分析。因此，这些结果将对神经胶质生物学产生重大影响-它们将定义神经元和神经胶质细胞内介导神经胶质细胞到神经元信号传导的分子通路，并为研究奠定基础 在哺乳动物模型中研究保守因子，以了解它们在人类健康和神经疾病中的功能。 公共卫生相关性：神经胶质细胞占成人大脑细胞的90%，参与从神经元支持到突触传递和复杂行为调节的过程。在这个应用中，我们提出的研究，以检查神经胶质细胞的神经元功能的调节。该提议与正常脑功能以及与胶质细胞功能障碍相关的许多神经和精神疾病具有重要意义。

DESCRIPTION (provided by applicant): There is controversy about the importance of glia-to-neuron communication in the adult brain, notwithstanding studies of "gliotransmission" 1, 2 and indications that astrocytes can modulate neuronal excitability and behavior in mammalian models 3, 4. For example, some have questioned the importance of glial Ca2+-dependent mechanisms in neuronal modulation 5-7. In addition, there is still limited knowledge of the mechanisms regulating gliotransmitter release, although certain studies suggest it involves vesicular exocytosis 2. In this application, we propose unbiased molecular genetic approaches to identify glial and neuronal factors essential for glia-to-neuron communication. We previously showed that elimination of a Drosophila glial-specific factor called Ebony genetically suppressed the hyperactivity phenotype of a Dopamine Transporter (DAT) mutant 8, indicating a role for glia-to-neuron communication in the regulation of activity level. In more recent published studies, we have demonstrated that adult Drosophila glial cells can physiologically modulate locomotor activity and circadian rhythmicity9. Our studies also demonstrate a critical role for Ca2+- dependent mechanisms and Drosophila astrocyte-like glia in the regulation of locomotor activity 9. In this R21 application, we propose studies to identify cell signaling mechanisms and intracellular pathways that are important for glia-to-neuron communication in adult animals. Drosophila is an excellent model for such studies as the glial classes of the adult brain have been well characterized 10-12 and one class has developmental, morphological and molecular similarities to mammalian astrocytes 11, 13, 14. Our studies will take advantage of multiple conditional perturbation methods that are cell type-specific and reversible to identify novel, conserved factors and intracellular pathways that mediate the glial modulation of neurons and behavior. Aim 1 will utilize Drosophila strains we recently developed and translational profiling methods to identify neuronal factors and molecular pathways that are modulated by glial signaling. Aim2 will use behavioral genetic strategies to define glial signaling mechanisms that are important for neuronal modulation. This proposal represents the first broad study of neuronal proteomic changes that occur as a consequence of glial signaling. It also represents the first genetic analysis of glial mechanisms that mediate the modulation of adult neurons. As such, the results will have a major impact on glial biology - they will define molecular pathways within neurons and glial cells that mediate glia-to-neuron signaling, and set the stage for studies of conserved factors in mammalian models to understand their functions in human health and neurological disease. PUBLIC HEALTH RELEVANCE: Glial cells constitute 90% of the cells of the adult brain and participate in processes ranging from neuronal support to the regulation of synaptic transmission and complex behaviors. In this application, we propose studies to examine the regulation of neuronal functions by glial cells. The proposal has significant relevance for normal brain function as well as the many neurological and psychiatric diseases that are associated with glial cell dysfunction.