The Role of Microglia in Models of ALS

小胶质细胞在 ALS 模型中的作用

• 批准号: 6898178
• 负责人: Stanley H. Appel
• 金额: $ 30.07万
• 依托单位: METHODIST HOSPITAL RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6898178
• 关键词: amyotrophic lateral sclerosis; bone marrow; cell morphology; chemokine; cytokine; dendritic cells; disease /disorder model; free radicals; gene expression; gene mutation; genetically modified animals; immune system; immunocytochemistry; laboratory mouse; lipopolysaccharides; microglia; motor neurons; nerve injury; nervous system disorder epidemiology; neural degeneration; neuromuscular disorder; neuropathology; polymerase chain reaction; superoxide dismutase; tumor necrosis factor alpha

DESCRIPTION (provided by applicant): Amyotrophic lateral sclerosis (ALS) is a rapidly progressive and fatal neuromuscular disease; approximately 10% of ALS patients have a family history of the disease. 20-25% of these familial ALS cases are caused by mutations in the Cu2+/Zn2+ superoxide dismutase gene (mSOD1). Overexpression of mSOD1 in transgenic mice also induces disease when ubiquitously expressed. However, evidence indicates that other cells, in addition to motor neurons, may be required to produce an ALS phenotype, i.e. non-cell autonomous. First, expression of mSOD1 in neurons-only and in astroglia-only did not produce disease; however, the level and timing of mSOD1 expression were not the same as the original mSOD1G93A mouse. Second, data from chimeric mice suggest that mSOD1-expressing neurons surrounded by normal glia appear uninjured, whereas normal neurons surrounded by mSOD-expressing glia appear abnormal. Third, pathology is present in several different cell types in the CNS, including neurons, astrocytes, and microglia. To determine the effects of mSOD1 expression in microglia and immune cells in ALS, we chose to use the PU.1-/- mouse. At birth, these mice lack macrophages, neutrophils, T and B cells, and importantly microglia; such mice survive only after bone marrow transplantation, resulting in donor-derived CNS microglia. Specifically, our aims are: Specific Aim 1: To determine if mSOD1 expression in microglia and immune cells alone can induce an ALS-like disease and/or initiate subclinical pathology. We are transplanting PU.1 -/- mice with mSOD1-, normal human (h)SOD1, and wildtype-derived bone marrow. PU.1 -/- mice transplanted with mSOD1 bone marrow did not appear to show any overt signs of motoneuron disease; even though the transplanted microglia may be morphologically different than microglia in control mice. We will examine these mice for subclinical pathology. Specific Aim 2: To determine if mSOD1 expression in microglia and immune cells is required for the initiation and/or amplification of an ALS-like disease in the mSOD1 mouse. We are transplanting the mSOD1 mice crossed with the PU.1 -/- mice (mSOD1/PU.I-/-). mSOD1/PU.1 -/- mice transplanted with wildtype bone marrow exhibit an ALS-like phenotype. Interestingly, the disease duration with these few mice may be longer than the duration of the mSOD1/PU.1 -/- mice transplanted with mSOD1 bone marrow. Specific Aim 3: To define potential mechanisms of microglia-mediated motor neuron injury. We are culturing primary motor neurons, which are injured by activated wildtype microglia, mSOD1 primary microglia appear more activated and we will assess their ability to injure wildtype and mSOD1 motor neurons.

描述（由申请人提供）：肌萎缩侧索硬化症（ALS）是一种快速进展且致命的神经肌肉疾病；大约 10% 的 ALS 患者有该病家族史。这些家族性 ALS 病例中 20-25% 是由 Cu2+/Zn2+ 超氧化物歧化酶基因 (mSOD1) 突变引起的。当 mSOD1 普遍表达时，转基因小鼠中 mSOD1 的过度表达也会诱发疾病。然而，有证据表明，除了运动神经元之外，可能还需要其他细胞来产生 ALS 表型，即非细胞自主性。首先，仅在神经元和星形胶质细胞中表达 mSOD1 不会产生疾病；然而，mSOD1表达的水平和时间与原始mSOD1G93A小鼠不同。其次，来自嵌合小鼠的数据表明，被正常神经胶质细胞包围的表达 mSOD1 的神经元似乎没有受伤，而被表达 mSOD 的神经胶质细胞包围的正常神经元则显得异常。第三，病理学存在于中枢神经系统中的几种不同细胞类型中，包括神经元、星形胶质细胞和小胶质细胞。为了确定 mSOD1 表达在 ALS 中小胶质细胞和免疫细胞中的影响，我们选择使用 PU.1-/- 小鼠。这些小鼠出生时缺乏巨噬细胞、中性粒细胞、T 细胞和 B 细胞，以及重要的小胶质细胞。这些小鼠只有在骨髓移植后才能存活，产生供体来源的中枢神经系统小胶质细胞。具体来说，我们的目标是： 具体目标 1：确定小胶质细胞和免疫细胞中的 mSOD1 表达是否可以单独诱导 ALS 样疾病和/或引发亚临床病理。我们正在向 PU.1 -/- 小鼠移植 mSOD1-、正常人 (h)SOD1 和野生型骨髓。移植 mSOD1 骨髓的 PU.1 -/- 小鼠似乎没有表现出任何明显的运动神经元疾病迹象；尽管移植的小胶质细胞在形态上可能与对照小鼠的小胶质细胞不同。我们将检查这些小鼠的亚临床病理学。具体目标 2：确定 mSOD1 小鼠中 ALS 样疾病的引发和/或放大是否需要小胶质细胞和免疫细胞中的 mSOD1 表达。我们正在移植与 PU.1 -/- 小鼠 (mSOD1/PU.I-/-) 杂交的 mSOD1 小鼠。移植野生型骨髓的 mSOD1/PU.1 -/- 小鼠表现出 ALS 样表型。有趣的是，这几只小鼠的疾病持续时间可能比移植 mSOD1 骨髓的 mSOD1/PU.1 -/- 小鼠的疾病持续时间更长。具体目标 3：确定小胶质细胞介导的运动神经元损伤的潜在机制。我们正在培养原代运动神经元，这些神经元被激活的野生型小胶质细胞损伤，mSOD1 原代小胶质细胞似乎更加激活，我们将评估它们损伤野生型和 mSOD1 运动神经元的能力。