Development of Microglia Knockout Mouse

小胶质细胞敲除小鼠的研制

• 批准号: 10040196
• 负责人: Bogoljub Ciric
• 金额: $ 15.6万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-15 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10040196
• 关键词: Acquired Immunodeficiency Syndrome; Address; Adrenoleukodystrophy; Adult; Age; Alzheimer' s Disease; Amyotrophic Lateral Sclerosis; Animal Model; Biology; Blood - brain barrier anatomy; Bone Marrow; Brain Diseases; Cause of Death; Cells; Central Nervous System Infections; Communicable Diseases; Data Analyses; Dependence; Development; Discipline; Disease; Disease model; Encephalitis; Ensure; Enterobacteria phage P1 Cre recombinase; Experimental Autoimmune Encephalomyelitis; Experimental Models; Exposure to; Funding; Generations; Genes; Genetic Transcription; Health; Homeostasis; Huntington Disease; Immune; Inflammation; Intervention; Knock-out; Knockout Mice; Longevity; LoxP-flanked allele; Macrophage Colony-Stimulating Factor Receptor; Maintenance; Malignant Neoplasms; Malignant neoplasm of brain; Microglia; Modeling; Mononuclear; Multiple Sclerosis; Mus; Myeloid Cells; Neuraxis; Outcome; Parkinson Disease; Partner in relationship; Phagocytes; Phenotype; Physiological Processes; Play; Receptor Gene; Receptor Signaling; Research; Research Personnel; Rett Syndrome; Role; Speed; Tamoxifen; The Jackson Laboratory; Time; TimeLine; Transgenic Mice; Transgenic Organisms; astrogliosis; base; bone cell; experimental study; macrophage; mouse model; nervous system development; novel; painful neuropathy; progenitor; progenitor system; targeted treatment; tool; transcription factor; treatment duration

SUMMARY Microglia are central nervous system (CNS) resident macrophages involved in maintaining CNS homeostasis. Importantly, they are also involved in a number of diseases, including Alzheimer’s disease, Huntington’s disease, amyotrophic lateral sclerosis, Parkinson’s disease, multiple sclerosis, infectious diseases and cancer. Despite their importance in health and disease, researchers still lack an experimental model that would enable simple and permanent depletion of microglia to study their functions and their potential as targets for therapy. The principal difficulty in studying microglia is their extensive similarity to other macrophages, which precludes depletion of microglia without concomitant depletion of macrophages. Making use of recent advances in microglia biology, we propose to characterize a transgenic mouse model, termed here Mg-ipKO that enables inducible, permanent, and highly selective depletion of microglia only. The depletion is based on expression of Sall1, a transcription factor expressed in microglia but not in other macrophages/myeloid cells. Sall1-driven expression of Cre recombinase will lead to knockout of CSF-1 receptor (CSF-1R) in microglia. Given that microglia survival is absolutely dependent on CSF-1R, its knockout will lead to depletion of microglia. The depletion will be tamoxifen-inducible and permanent. A similar concept for short- term microglia depletion by Sall1-driven expression of Cre to knockout CSF-1R has recently been proven successful, supporting the feasibility of the approach that we propose. We have recently generated novel Sall1-FRT-Cre transgenic mouse line, and we are currently crossing these mice with two other transgenic mouse lines (obtained from The Jackson Laboratory) to generate final triple transgenic Mg-ipKO mice with the capacity for inducible microglia depletion. We anticipate that we will have generated Mg-ipKO mice by the time funding for this project may start, allowing for an immediate start of experiments with these mice. We propose the specific aim: To characterize microglia depletion and its effects in Mg-ipKO mice. To determine the usefulness of the model, we will induce microglia depletion in adult Mg-ipKO mice by tamoxifen treatment. We will then determine the extent of the depletion and optimize tamoxifen treatment if necessary. Furthermore, we will characterize potential consequences of the depletion on CNS homeostasis (blood-brain barrier integrity, CNS inflammation, astrogliosis) and determine if, over time, the CNS repopulates with microglia that originate from either CNS progenitors, or with macrophages of bone marrow origin. We expect that by the completion of this proposed research we will have developed and characterized an advanced transgenic mouse model for the depletion of microglia that overcomes the limitations of existing approaches and provides a highly useful research tool for multiple biomedical disciplines.

总结 小胶质细胞是中枢神经系统（CNS）内的巨噬细胞，参与维持CNS内稳态。 重要的是，它们还与许多疾病有关，包括阿尔茨海默病、亨廷顿病、 肌萎缩侧索硬化症、帕金森氏病、多发性硬化症、传染病和癌症。尽管 尽管它们在健康和疾病中的重要性，研究人员仍然缺乏一个实验模型， 和永久性耗竭小胶质细胞以研究它们的功能和它们作为治疗靶点的潜力。的 研究小胶质细胞的主要困难是它们与其他巨噬细胞的广泛相似性，这排除了 消耗小胶质细胞而不伴随消耗巨噬细胞。 利用小胶质细胞生物学的最新进展，我们提出了一个转基因小鼠的特点， 模型，在此称为Mg-ipKO，其能够仅诱导、永久和高度选择性地消耗小胶质细胞。 这种缺失是基于Sall 1的表达，Sall 1是一种在小胶质细胞中表达但在其他细胞中不表达的转录因子。 巨噬细胞/骨髓细胞。Cre重组酶Sall 1驱动的表达将导致CSF-1受体的敲除 （CSF-1R）。鉴于小胶质细胞的存活绝对依赖于CSF-1 R，其敲除将导致 小胶质细胞的衰竭消耗将是他莫昔芬诱导的和永久的。类似的概念简称- 最近已经证明，通过Sall 1驱动Cre表达以敲除CSF-1 R， 成功，支持我们提出的方法的可行性。 我们最近已经产生了新的Sall 1-FRT-Cre转基因小鼠系，我们目前正在杂交 将这些小鼠与另外两个转基因小鼠系（从杰克逊实验室获得）杂交以产生最终的三联体 具有可诱导小胶质细胞耗竭能力的转基因Mg-ipKO小鼠。我们预计， 产生的Mg-ipKO小鼠的时间为这个项目的资金可能开始，允许立即开始 用这些老鼠做实验。 我们提出的具体目标：表征小胶质细胞耗竭及其对Mg-ipKO小鼠的影响。 为了确定该模型的有用性，我们将通过他莫昔芬诱导成年Mg-ipKO小鼠中的小胶质细胞耗竭 治疗然后，我们将确定消耗的程度，并在必要时优化他莫昔芬治疗。 此外，我们将描述消耗对CNS稳态（血脑平衡）的潜在后果。 屏障完整性、CNS炎症、星形胶质细胞增生），并确定随着时间的推移，CNS是否重新充满小胶质细胞 来源于CNS祖细胞或骨髓来源的巨噬细胞。 我们预计，通过完成这项拟议的研究，我们将开发和表征 一种先进的转基因小鼠模型，用于消除小胶质细胞，克服了现有的局限性， 方法，并为多个生物医学学科提供了非常有用的研究工具。