Harnessing microglia towards repair vs. damage: Does p38 MAPK hold the reins?

描述（由申请人提供）： 阿尔茨海默病（AD）的主要病理组成部分是脑炎症。已知小胶质细胞（“脑巨噬细胞”）的活化发生在AD中，并被认为有助于神经元损伤。外周巨噬细胞的研究已经确定存在多种不同的巨噬细胞活化状态，最近的研究已经证实了小胶质细胞中的这些发现。大胶质细胞/小胶质细胞可以广泛地定义为经典激活或替代激活。经典活化的巨噬细胞的典型特征是释放促炎细胞因子（例如IL-12、TNF-1）和活性氧和氮物质，它们是已知引起神经元损伤的炎症反应的组分。然而，并非所有形式的小胶质细胞激活都是有害的。某些形式的小胶质细胞活化是有益的，例如导致淀粉样蛋白β（A2）去除或清除的替代活化反应。该提议将检验以下假设：p381 MAP激酶信号级联导致小胶质细胞活化的有害形式，并且阻断p381通路将减少活化的小胶质细胞的有害反应而不影响有益反应。目的1将测试的假设，激活的p381 MAP激酶信号级联发生在小胶质细胞在早期阶段的发病机制在AD相关的转基因小鼠模型（Tg 6799小鼠）。目的2将使用一种新的，脑渗透，小分子抑制剂p381来测试的假设，抑制p381活性将减缓Tg 6799小鼠的病理。这一目标将提供使用药理学工具、神经退行性疾病转基因模型和治疗靶点验证方面的培训。目的3将评估p381在小胶质细胞与其他神经细胞类型中在A2产生的损伤中的相对贡献。为了测试这一目标，我们将在仅在小胶质细胞中具有p381基因缺失的小鼠中使用A2输注AD相关模型。这一目标将提供使用cre/lox系统的条件性基因敲除小鼠模型和小鼠立体定位手术的培训。该项目的成功完成将为关键调节蛋白p381如何参与CNS病理生理学机制和干预反应提供机制见解，并将为针对这一重要蛋白激酶的后续CNS治疗开发活动奠定基础。职业发展计划已经正式制定，包括正式课堂和专业讲习班的参与，在实验室和研究小组一级定期介绍拟议的研究计划和结果，以研讨会的形式介绍独立的研究结果，参加国家和国际科学会议，编写研究建议和出版物，以及发展其他职业发展技能。一个经验丰富的导师，丰富的科学环境，以及有组织的教育和培训计划将确保申请人有最佳的机会，科学成长，职业发展和发展成为一个独立的学术研究者。 公共卫生相关性： 神经炎症越来越多地被认为是许多神经退行性疾病的病理学贡献者，例如阿尔茨海默病，一种没有有效治疗或治愈的破坏性衰老疾病。该项目的成功完成将为关键调节蛋白p381 MAPK如何参与疾病相关应激源引起的脑促炎反应和CNS功能障碍提供机制性见解。此外，结果将描绘小胶质细胞p381 MAPK的疾病相关的病理反应的相对重要性。从长远来看，拟议研究产生的见解和知识将为未来开发新类别的疾病修饰疗法和更全面地解释疾病进展研究提供更坚实的基础。

DESCRIPTION (provided by applicant): A primary pathological component of Alzheimer's disease (AD) is brain inflammation. Activation of microglia, the "macrophages of the brain", is known to occur in AD and believed to contribute to the neuronal damage. Studies of peripheral macrophages have determined that multiple distinct activation states of macrophages exist, and recent studies have confirmed these findings in microglia. Macrophages/microglia can be broadly defined as being classically activated or alternatively activated. Classically activated macrophages are typified by the release of proinflammatory cytokines (e.g. IL-12, TNF-1) and reactive oxygen and nitrogen species, which are components of the inflammatory response that is known to cause neuronal damage. However, not all forms of microglia activation are detrimental. Some forms of microglia activation are beneficial, such as alternative activation responses that lead to removal or clearance of amyloid beta (A2). This proposal will test the hypothesis that the p381 MAP kinase signaling cascade leads to the detrimental forms of microglia activation, and that blocking the p381 pathway will decrease the detrimental responses of activated microglia without affecting the beneficial responses. Aim 1 will test the hypothesis that activation of the p381 MAP kinase signaling cascade occurs in microglia during the early phase of pathogenesis in an AD-relevant transgenic mouse model (the Tg6799 mouse). Aim 2 will use a novel, brain-penetrant, small molecule inhibitor of p381 to test the hypothesis that suppression of p381 activity will slow the pathology in the Tg6799 mouse. This aim will provide training in the use of pharmacological tools, transgenic models of neurodegenerative disease, and therapeutic target validation. Aim 3 will evaluate the relative contribution of p381 in microglia vs. other neural cell types in the damage produced by A2. To test this aim, we will use an A2 infusion AD-relevant model in a mouse with a genetic deletion of p381 only in the microglia. This aim will provide training in the use of conditional knockout mouse models using the cre/lox system, and stereotaxic surgery in mice. Successful completion of this project will provide mechanistic insight into how the key regulatory protein p381 is involved in CNS pathophysiology mechanisms and intervention responses, and will form the foundation for follow-on CNS therapeutic development campaigns targeting this important protein kinase. A Career Development Plan has been formalized, and includes a combination of formal classroom and specialty workshop participation, regular presentations of proposed research plans and results at the laboratory and research group level, presentation of independent research results in seminar format, participation in national and international scientific meetings, preparation of research proposals and publications, and development of additional career- enhancing skills. An experienced mentor, a rich scientific environment, and an organized educational and training plan will assure that the applicant has optimal opportunities for scientific growth, career enhancement and development into an independent academic investigator. PUBLIC HEALTH RELEVANCE: Neuroinflammation is increasingly being recognized as a contributor to pathology in many neurodegenerative diseases, such as Alzheimer's disease, a devastating disease of aging with no effective treatment or cure. Successful completion of this project will provide mechanistic insight into how the key regulatory protein, p381 MAPK, is involved in brain pro-inflammatory responses and CNS dysfunction caused by disease-relevant stressors. In addition, the results will delineate the relative importance of microglial p381 MAPK to the disease-relevant pathological responses. Longer term, the insights and knowledge generated by the proposed studies will provide a firmer foundation for future development of new classes of disease- modifying therapeutics and fuller interpretation of disease progression investigations.