Contribution of astrocytes to mutant FUS-linked Amyotrophic Lateral Sclerosis

摘要 这个项目的目标是确定突变融合在一起的机制 肉瘤(FUS)诱导FUS相关星形胶质细胞的病理和致病改变 肌萎缩侧索硬化症(FUS-ALS)。 已知星形胶质细胞在某些(但不是所有)形式的星形细胞瘤中促进疾病进展。 直到最近，对星形胶质细胞在FUS-ALS中的作用还知之甚少。 我们的实验室最近发表了第一个体外证据，星形胶质细胞表达 突变形式的FUS(变FUS)，而不是野生型FUS，对运动神经元产生毒性 通过激活NFkB途径导致分泌因子的释放(S)，以及 主要是肿瘤坏死因子α(起亚和麦卡沃伊等人，Glia，2018年)。以肿瘤坏死因子α−依赖的方式，运动 暴露在MUTFUS星形胶质细胞条件培养液中的神经元显示AMPA受体 使它们对兴奋性毒性损伤敏感的变化，导致细胞死亡。激活 星形细胞肿瘤坏死因子B和肿瘤坏死因子α的释放似乎是突变的FUS-ALS特异的，强调 按顺序剖析每种形式的肌萎缩侧索硬化症的发病机制的重要性 开发量身定制的治疗方法。 在这项建议中，我们将重点研究MUTFUS-ALS，并将研究(1)通过 FUS中哪些致病突变改变了星形胶质细胞的生物学？(2)如何突变 在体内，表达FUS的星形胶质细胞会影响脊髓内其他细胞的活性。这个 最终目标是确定MUTFUS目标最终发展的关键路径 特定的疗法。最终，我们的FUS-ALS模型可以作为一个平台 与模仿其他形式的肌萎缩侧索硬化症的模型进行比较分析，以确定基因- 疾病发病机制的特异性和趋同性以及更全球化的机制。为我们的 研究中，我们将使用由(1)原代啮齿动物星形胶质细胞组成的体外和体内模型 转导不同的FUS突变以及来自FUS的iPSC来源的星形胶质细胞 (2)MUTFUS ALS小鼠模型。体外系统将允许我们 剖析MUTFUS靶向星形胶质细胞的精确机制 确定突变FUS如何改变患者的星形胶质细胞生物学。鼠标模型将允许 美国将研究MUTFUS星形胶质细胞如何影响体内复杂的细胞环境 布景。

ABSTRACT The goal of this project is to identify the mechanisms by which mutations in Fused in Sarcoma (FUS) induce pathological and pathogenic changes in astrocytes in FUS-linked Amyotrophic Lateral Sclerosis (FUS-ALS). Astrocytes are known to contribute to disease progression in some, but not all, forms of ALS and, until recently, not much was known about the role of astrocytes in FUS-ALS. Our lab has recently published the first in vitro evidence that astrocytes expressing mutant forms of FUS (mutFUS), but not wild-type FUS, exert toxicity on motor neurons through activation of the NFkB pathway leading to the release of secreted factor(s), and primarily TNFα (Kia & McAvoy et al., GLIA, 2018). In a TNFα−dependent manner, motor neurons exposed to the conditioned medium of mutFUS astrocytes show AMPA receptor alterations that sensitize them to excitotoxic damage, leading to cell death. Activation of astrocytic NFkB and TNFα release seems to be specific to mutFUS-ALS, underscoring the importance of dissecting disease mechanisms specific to each form of ALS in order to develop tailored therapies. In this proposal, we will focus on mutFUS-ALS and will study (1) the mechanisms by which disease-casuative mutations in FUS alter astrocyte biology and (2) how mutant FUS expressing astrocyte affect the viability of other cells in the spinal cord in vivo. The ultimate goal is to identify key pathways targeted by mutFUS to eventually develop specific therapies. Ultimately, our models of FUS-ALS may serve as a platform for a comparative analysis with models mimicking other forms of ALS, so to identify genotype- specific vs. converging and more global mechanisms of disease pathogenesis. For our studies, we will use in vitro and in vivo models consisting of (1) primary rodent astrocytes transduced with different FUS mutations as well as iPSc-derived astrocytes from FUS patients; (2) an in vivo mouse model of mutFUS ALS. The in vitro systems will allow us to dissect the precise mechanisms by which mutFUS targets the astrocytes and to determine how mutFUS alters astrocyte biology in patients. The mouse model will allow us to study how mutFUS astrocytes affect the cellular environment in a complex in vivo setting.