Is Toll-like receptor-3 signaling involved in Alzheimer's disease?

Toll 样受体 3 信号传导是否与阿尔茨海默病有关？

• 批准号: 9212226
• 负责人: Douglas Gordon Walker
• 金额: $ 6.5万
• 依托单位: ARIZONA STATE UNIVERSITY-TEMPE CAMPUS
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-30 至 2017-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9212226
• 关键词: Toll; like; receptor; signaling; involved

DESCRIPTION (provided by applicant): This project will examine the functional consequences of Toll-like receptor-3 (TLR-3) expression as it relates to features of Alzheimer's disease. Toll-like receptors, which are a family of 10 related pattern recognition receptors, have multiple functions in coordinating host defenses to microbial agents. We identified TLR-3 as being prominently expressed by microglia in AD brains, particularly those plaque-associated, while other significant TLR were not associated with glia. As TLR-3 signaling can have different consequences, we consider it timely to investigate in AD and related relevant human model systems. As TLR-3 is primarily an endosomal localized receptor, its function and the consequence of its activation to AD requires investigation. We have developed a central hypothesis based on preliminary results that stimulation of microglia and astrocytes with ligands for TLR-3 will induce anti-inflammatory and protective responses, and also promote A� removal. As stimulation of related endosomal TLR-9 has been suggested as a therapeutic option for removing amyloid from brain, we are positing that TLR-3 activation may have similar outcome. The goal of this project is to identify the nature of microglia and astrocyte responses to TLR-3 ligands in the presence of A�. This will be investigated in vitro in microglia and astrocyte cultures derived from postmortem brains, and in ex-vivo human brain slice cultures. We will also determine if chronic TLR-3 ligand administration to plaque-developing transgenic mice affects A� load and related neuropathology. We will investigate these features in three related aims. Specific Aim 1; We will investigate what are the functional consequences of TLR-3 activation of human microglia and astrocytes on production of proinflammatory and anti-inflammatory cytokines and neurotoxic factors. Cultures from AD and normal brains will be stimulated with a TLR-3 ligand in the presence and absence of A�. We will use antibody arrays to measure cellular responses, and also in vitro neurotoxicity and neuroprotective assays to determine consequences of TLR-3 stimulation. Specific Aim 2; We will investigate what are the functional consequences of TLR-3 activation of human microglia and astrocytes on uptake and degradation of amyloid beta peptide. Both aims will be carried out in vitro using the TLR3- ligand poly IC and/or A� stimulated human microglia and astrocytes described in Aim 1. Specific Aim 3; We will use two complex systems, where interactions of microglia, astrocytes and neurons occur, to investigate the same features as in aims 1 and 2. We will use ex vivo slice cultures of human brains and also amyloid plaque developing transgenic mice to determine whether TLR-3 activation promotes or reduces inflammation and neuronal survival, and increases or decreases glial uptake and degradation of A�.

描述（由申请人提供）：该项目将研究 Toll 样受体 3 (TLR-3) 表达的功能后果，因为它与阿尔茨海默病的特征相关。 Toll 样受体是由 10 种相关模式识别受体组成的家族，在协调宿主对微生物制剂的防御方面具有多种功能。我们发现 TLR-3 在 AD 大脑中的小胶质细胞中显着表达，特别是那些与斑块相关的小胶质细胞，而其他重要的 TLR 与神经胶质细胞无关。由于 TLR-3 信号传导可能会产生不同的后果，因此我们认为现在应该对 AD 和相关的人类模型系统进行研究。由于 TLR-3 主要是一种内体定位受体，因此其功能及其激活对 AD 的影响需要研究。我们根据初步结果提出了一个中心假设，即用 TLR-3 配体刺激小胶质细胞和星形胶质细胞将诱导抗炎和保护反应，并促进 A� 去除。由于相关内体 TLR-9 的刺激已被建议作为从大脑中去除淀粉样蛋白的治疗选择，我们假设 TLR-3 激活可能具有类似的结果。该项目的目标是确定 A� 存在下小胶质细胞和星形胶质细胞对 TLR-3 配体反应的性质。这将在来自死后大脑的小胶质细胞和星形胶质细胞培养物以及离体人脑切片培养物中进行体外研究。我们还将确定对形成斑块的转基因小鼠长期给予 T​​LR-3 配体是否会影响 A� 负荷和相关的神经病理学。我们将在三个相关目标中研究这些功能。具体目标1；我们将研究人小胶质细胞和星形胶质细胞的 TLR-3 激活对促炎和抗炎细胞因子以及神经毒性因子产生的功能影响。在 A� 存在和不存在的情况下，来自 AD 和正常大脑的培养物将受到 TLR-3 配体的刺激。我们将使用抗体阵列来测量细胞反应，并使用体外神经毒性和神经保护测定来确定 TLR-3 刺激的后果。具体目标2；我们将研究人类小胶质细胞和星形胶质细胞的 TLR-3 激活对淀粉样蛋白 β 肽的摄取和降解的功能影响。这两个目标都将使用目标 1 中描述的 TLR3 配体多聚 IC 和/或 Aβ 刺激的人小胶质细胞和星形胶质细胞在体外进行。具体目标 3；我们将使用两个复杂的系统，其中小胶质细胞、星形胶质细胞和神经元发生相互作用，以研究与目标 1 和 2 中相同的特征。我们将使用人脑的离体切片培养物以及淀粉样斑块发育的转基因小鼠来确定 TLR-3 激活是否促进或减少炎症和神经元存活，以及增加或减少神经胶质细胞对 A 的摄取和降解。