What do microglia do? Dissecting their function in CNS health and disease

小胶质细胞有什么作用？

• 批准号: 8836424
• 负责人: Mariko L. Bennett
• 金额: $ 0.91万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-26 至 2015-09-20
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8836424
• 关键词: Ablation; Adult; Antibodies; Brain; Cells; Crush Injury; Development; Diphtheria Toxin; Disease; Embryo; Event; Gene Expression; Genetic Recombination; Goals; Health; Hematopoietic System; Immune; Immune response; Immunohistochemistry; In Situ Hybridization; Inflammation; Inflammatory Response; Injury; Integral Membrane Protein; Label; Messenger RNA; Microglia; Modeling; Mus; Myelogenous; Myeloid Cells; N-terminal; Nerve Crush; Nerve Tissue; Nervous System Trauma; Neuraxis; Optic Nerve; Pathologic; Phenotype; Physiological Processes; Process; Proteins; Reporter; Reporting; Role; Severities; Site; Synapses; Tamoxifen; Testing; Time; Tissues; Transgenic Mice; Western Blotting; base; central nervous system injury; design; hematopoietic tissue; injured; injury and repair; insight; macrophage; mouse Cre recombinase; mouse development; nervous system development; nervous system disorder; neuroprotection; new therapeutic target; novel; optic nerve regeneration; postnatal; precursor cell; prevent; repaired; research study; response to injury; therapeutic target; tissue repair; tool

DESCRIPTION (provided by applicant): What do microglia do? Microglia are myeloid-derived residents of the brain that can mount immune responses to pathologic events in the brain and periphery. Recently, we and others have identified roles for microglia in physiologic processes of the CNS, such as in synapse elimination during development. However, the inability to reliably distinguish microglia from closely related myeloid cells confounds many reports of microglial function in health and disease. Therefore, we sought out a protein marker that would allow the reliable identification, targeting, and characterization of microglia. I identified TM119 as such a marker by a screen based on our extensive cell specific gene expression arrays and confirmed with in situ hybridization. In this application, I will test the hypothesis that a subset of microglia are "alternatively activated", meaning that upon activation they limit inflammation and promote tissue repair, and that these microglia limit CNS injury. I wil then test if selective loss of microglia hinders CNS repair. In the first aim, I will characterize TM119 expression throughout development and test a TM119-based tool, a TM119/CreERT2 BAC transgenic mouse, to genetically target microglia. In the second aim, I will use this mouse to specifically prevent alternative activation of microglia and examine the effect of this on injur severity following crush injury to the optic nerve. In the final aim, I will ablate microglia using Diphtheria toxin targeted to microglia with the TM119/CreERT2 mouse to determine if they are required for CNS repair and neuroprotection. These studies have the potential to dissect and understand, for the first time, the specific contribution of microglia to CNS injury and repair.

描述（由申请人提供）：小胶质细胞有什么作用？小胶质细胞是大脑中骨髓来源的居民，可以对大脑和外周的病理事件产生免疫反应。最近，我们和其他人已经确定了小胶质细胞在中枢神经系统生理过程中的作用，例如在发育过程中突触消除中的作用。然而，由于无法可靠地区分小胶质细胞与密切相关的骨髓细胞，许多关于小胶质细胞在健康和疾病中的功能的报道令人困惑。因此，我们寻找一种蛋白质标记物，能够可靠地识别、靶向和表征小胶质细胞。我通过基于我们广泛的细胞特异性基因表达阵列的筛选，确定了 TM119 作为这样的标记，并通过原位杂交进行了确认。在本申请中，我将测试以下假设：小胶质细胞的一个子集被“交替激活”，这意味着它们在激活后会限制炎症并促进组织修复，并且这些小胶质细胞会限制中枢神经系统损伤。然后我将测试小胶质细胞的选择性丢失是否会阻碍中枢神经系统的修复。第一个目标是，我将表征整个开发过程中 TM119 的表达，并测试基于 TM119 的工具（TM119/CreERT2 BAC 转基因小鼠），以对小胶质细胞进行遗传靶向。在第二个目标中，我将使用这只小鼠专门防止小胶质细胞的替代激活，并检查其对视神经挤压损伤后损伤严重程度的影响。在最终目标中，我将使用消融小胶质细胞 使用 TM119/CreERT2 小鼠将白喉毒素靶向小胶质细胞，以确定中枢神经系统修复和神经保护是否需要它们。这些研究有可能首次剖析和理解小胶质细胞对中枢神经系统损伤和修复的具体贡献。