ANALYZING MICROGLIA-DERIVED TOXICITY TO MOTOR NEURONS IN ALS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 肌萎缩侧索硬化症(ALS)是一种起病晚、导致瘫痪的神经退行性疾病。普遍表达的铜/锌超氧化物歧化酶(SOD1)基因突变是家族性ALS的最众所周知的原因，表达突变SOD1的转基因小鼠会发展为晚发型的ALS样疾病。已知ALS上、下运动神经元的变性是ALS瘫痪的原因，表达突变型SOD1的神经胶质细胞类型参与了ALS的发病机制。我们发现，小胶质细胞是中枢神经系统的免疫细胞，是重要的参与者，因为减少巨噬细胞/小胶质细胞中的突变SOD1可以延长ALS小鼠的存活率。小胶质细胞在中枢神经系统的任何损伤中都被激活，包括散发性和家族性肌萎缩侧索硬化症，当激活时，它们释放对神经元有毒或营养的因子。因此，识别这些因素可能是寻找与运动神经元死亡有关的新靶点的关键。由于从巨噬细胞/小胶质细胞下调突变的SOD1可以减缓ALS小鼠的疾病进展，突变的SOD1必须直接作用于小胶质细胞，才能对运动神经元产生毒性。因此，表达突变型或野生型SOD1的小胶质细胞将通过质谱学筛选它们可以释放的不同因子。来自培养的小胶质细胞的条件培养液将被用作释放小胶质细胞因子的来源，表达突变型SOD1的细胞的培养液将与表达野生型SOD1的小胶质细胞的培养液进行比较。鉴定表达突变型SOD1的小胶质细胞和对照小胶质细胞之间的差异有助于阐明小胶质细胞所涉及的细胞内途径和释放的导致运动神经元死亡的毒性因子。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Amyotrophic Lateral Sclerosis (ALS) is a late onset neurodegenerative disease leading to paralysis. Mutations in the gene for the ubiquitously expressed Cu/Zn superoxide dismutase (SOD1) are the best-known cause for familial ALS and transgenic mice constitutively expressing mutant SOD1 develop a late-onset, ALS-like disease. It is known that degeneration of upper and lower motor neurons is responsible for paralysis in ALS and that glial cell types expressing mutant SOD1 contribute to disease mechanism. We showed that microglial cells, the immune cells of the CNS, were important players, since diminishing mutant SOD1 specifically in macrophages/ microglial cells extended survival in ALS mice. Microglial cells are activated in any injury of the CNS including sporadic and familial ALS and when activated, they release factors that can be toxic or trophic for neurons. Therefore, identifying those factors could be a key to finding new targets implicated in motor neuron death. As downregulating mutant SOD1 from macrophages/microglial cells slowed disease progression in ALS mice, mutant SOD1 must act directly within microglial cells to generate toxicity toward motor neurons. Therefore, microglial cells expressing mutant or wild-type SOD1 will be screened for the different factors that they can release using Mass Spectrometry. Conditioned medium from cultured microglial cells will be used as a source of released microglial factors and medium from cells expressing mutant SOD1 will be compared to medium from wild-type SOD1 expressing microglial cells. Identification of the differences between mutant SOD1 expressing microglial cells and control microglial cells should help elucidate the intracellular pathways involved and the toxic factors released by microglial cells that contribute to motor neuron death.