Functional Interaction of Amyloid-b Protein with Glial Toll-Like Receptors

描述（由申请人提供）：阿尔茨海默病（AD）是一种进行性神经退行性疾病，其特征在于痴呆增加并最终死亡。AD的突出病理学特征包括严重的神经元损失、聚集的淀粉样蛋白（A）在老年斑和弥漫性沉积物中的积累以及神经元性tau蛋白缠结。人们普遍认为，A积累是AD的主要原因，但仍存在几个核心问题。1)什么样的A？结构、聚集状态或物种对AD有贡献？2）人类免疫系统如何识别和响应A？有意义的数据表明，AD脑中对A？的持续炎症反应包括A？沉积物周围活化的小胶质细胞和细胞因子的聚集。令人惊讶的是，并非所有的A？沉积物都引起炎症反应，这表明A？形态/结构影响反应。这些结果提出了几个令人困惑的问题，关于A？引起炎症反应的机制。最近的工作已经确定，先天免疫系统的Toll样受体（TLR）介导对聚集的A？的促炎反应，这表明A？可能具有与微生物大分子相似的结构元件。 本提案中的工作将利用生物物理学和细胞研究来建立原代小鼠小胶质细胞和星形胶质细胞中A？形态/结构与炎症之间的联系。第一个研究目标将调查影响A？聚集和结构的各种条件，并确定导致初级小胶质细胞和星形胶质细胞中最大A？促炎活性（细胞因子产生）的条件。各种生物物理技术将用于进一步了解A？结构和神经胶质激活之间的联系。第二个研究目标将利用正常和转基因敲除小鼠来鉴定和表征介导胶质细胞表面和细胞内A？生物活性的TLR、辅助受体和蛋白辅助因子的复合物。进一步了解A？活性可能有助于解释为什么人类免疫系统在控制AD方面是无效的，并提供治疗缓解的合理点。 该项目的科学和生物医学重要性在于其对阿尔茨海默病的理解的直接贡献。该项目的另一个同样重要的方面是为研究生和本科生研究人员提供培训机会。拟议的研究，这是一个细胞生物学，生物化学，生物物理学，纳米科学和光谱学的融合，将吸引学生参与跨学科研究的多元化群体。这一广泛的科学将促进来自不同部门的学生和教师之间的协作和互动。该项目的主要使命是对阿尔茨海默病产生重大影响。一个同样重要的目标是通过在多个研究领域获得知识，学习和完善实验室技能，以及解释，展示和出版有意义的结果，为学生未来的跨学科研究做好准备。 公共卫生相关性：从2000年到2005年，阿尔茨海默病（AD）的死亡人数增加了45%，而心脏病、乳腺癌、前列腺癌和中风的死亡人数在同一时期有所下降。AD预计到21世纪中叶将达到史诗般的比例，压倒医疗资源。开发预防或治疗AD的治疗方法的最适当方法是了解该疾病的潜在生化特征。该提案将研究AD与人类免疫反应之间的分子机制，可能导致利用我们自己的免疫系统对抗AD的疗法。此外，该项目将对各级学生进行严格的研究培训，最终将对公共卫生产生积极的长期影响。

DESCRIPTION (provided by applicant): Alzheimer's disease (AD) is a progressive neurodegenerative illness characterized by increasing dementia and ultimately death. Outstanding pathological features of AD include severe neuronal loss, accumulation of aggregated amyloid-¿ protein (A¿) in senile plaques and diffuse deposits, and neurofibrillary tau tangles. It is generally agreed that A¿ accumulation is a primary cause of AD yet several central questions remain. 1) What A¿ structure, aggregation state or species contributes to AD? and 2) How does the human immune system recognize and respond to A¿? Significant data demonstrate a sustained inflammatory response to A¿ in the AD brain which includes clustering of activated microglia and cytokines around A¿ deposits. Surprisingly, not all A¿ deposits provoke an inflammatory response suggesting that A¿ morphology/structure influences the response. These results raise several puzzling questions regarding the mechanism by which A¿ provokes an inflammatory response. Recent work has established that Toll-like receptors (TLRs) of the innate immune system mediate a proinflammatory response to aggregated A¿ suggesting that A¿ may possess structural elements that are similar to microbial macromolecules. The work in this proposal will utilize biophysical and cellular studies to establish a connection between A¿ morphology/structure and inflammation in primary murine microglia and astrocytes. The first research aim will investigate a variety of conditions that influence A¿ aggregation and structure and identify the conditions that result in the greatest A¿ proinflammatory activity (cytokine production) in primary microglia and astrocytes. A variety of biophysical techniques will be used to further understand the connection between A¿ structure and glial activation. The second research aim will utilize normal and transgenic knockout mice to identify and characterize complexes of TLRs, co-receptors, and protein cofactors that mediate A¿ bioactivity at the glial cell surface and inside the cell. Further understanding of A¿ activity may help explain why the human immune system is ineffective at controlling AD and provide a legitimate point of therapeutic mitigation. The scientific and biomedical importance of this project is its direct contribution to the understanding of Alzheimer's disease. The additional and equally important aspect of the project is the training opportunities that it provides for graduate and undergraduate researchers. The proposed research, which is a blend of cell biology, biochemistry, biophysics, nanoscience, and spectroscopy, will attract a diverse group of students to participate in interdisciplinary studies. This broad range of science will promote collaborative work and interactions between students and faculty from different departments. The primary mission of the project is to make a significant impact on Alzheimer's disease. An equally important objective is to prepare students for future interdisciplinary research by gaining knowledge in a multiple research areas, learning and refining laboratory skills, and interpreting, presenting, and publishing meaningful results. PUBLIC HEALTH RELEVANCE: Deaths from Alzheimer's disease (AD) have increased by 45% from 2000 to 2005, while deaths from heart disease, breast cancer, prostate cancer, and stroke have declined during the same time period. AD is projected to reach epic proportions by the middle of the 21st century overwhelming medical resources. The most appropriate way to develop treatments that will prevent or treat AD is to understand the underlying biochemical features of the disease. This proposal will examine molecular mechanisms linking AD and the human immune response potentially leading to therapies that utilize our own immune system to fight AD. Furthermore, the project will incorporate rigorous research training of students at all levels that will ultimately have a positive long-term impact on public health.