ANALYZING MICROGLIA-DERIVED TOXICITY TO MOTOR NEURONS IN ALS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 肌萎缩侧索硬化症（ALS）是一种迟发性神经退行性疾病，可导致瘫痪。普遍表达的Cu/Zn超氧化物歧化酶（SOD 1）基因突变是家族性ALS的最常见原因，组成型表达突变SOD 1的转基因小鼠会发展为迟发性ALS样疾病。已知上运动神经元和下运动神经元的变性是ALS中瘫痪的原因，并且表达突变体SOD 1的神经胶质细胞类型有助于疾病机制。我们发现，小胶质细胞，中枢神经系统的免疫细胞，是重要的球员，因为减少突变SOD 1，特别是在巨噬细胞/小胶质细胞延长ALS小鼠的生存。小胶质细胞在CNS的任何损伤中被激活，包括散发性和家族性ALS，并且当被激活时，它们释放对神经元可能有毒或营养的因子。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。由于下调来自巨噬细胞/小胶质细胞的突变体SOD 1减缓了ALS小鼠的疾病进展，突变体SOD 1必须直接在小胶质细胞内起作用以产生对运动神经元的毒性。因此，表达突变型或野生型SOD 1的小胶质细胞将使用质谱法筛选它们可以释放的不同因子。将来自培养的小胶质细胞的条件培养基用作释放的小胶质细胞因子的来源，并且将来自表达突变体SOD 1的细胞的培养基与来自表达野生型SOD 1的小胶质细胞的培养基进行比较。突变体SOD 1表达的小胶质细胞和控制小胶质细胞之间的差异的鉴定应有助于阐明所涉及的细胞内途径和小胶质细胞释放的毒性因子，有助于运动神经元死亡。

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.