Astrocytic exocytosis of ATP in amyloid pathology and Alzheimer's disease

淀粉样蛋白病理学和阿尔茨海默病中 ATP 的星形细胞胞吐作用

• 批准号: 10722422
• 负责人: Weikang Cai
• 金额: $ 30.6万
• 依托单位: NEW YORK INST OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10722422
• 关键词: Abeta clearance; Abeta synthesis; Age; Age Months; Alzheimer' s Disease; Alzheimer' s disease brain; Alzheimer' s disease model; Amyloid beta-42; Amyloid beta-Protein; Amyloid deposition; Astrocytes; Attenuated; Bioinformatics; Brain; Cell physiology; Chronic; Cognitive; Data; Deposition; Development; Disease Progression; Enzyme-Linked Immunosorbent Assay; Exocytosis; Female; Future; Gene Mutation; Genetic; Genetic Transcription; Grant; Immunofluorescence Immunologic; Impaired cognition; Impairment; Individual; Inflammation Mediators; Inflammatory; Investigation; Learning; Length; Lysosomes; Memory; Microdialysis; Microglia; Modeling; Morphology; Mus; Neurodegenerative Disorders; Neurofibrillary Tangles; Neuroglia; Neurons; Neurotransmitters; Nucleotides; Pathway interactions; Peptides; Physiological; Play; Production; Research; RiboTag; Role; Senile Plaques; Signal Transduction; Synapses; Synaptic plasticity; System; Testing; Time; Traumatic Brain Injury; Western Blotting; abeta deposition; amyloid pathology; analog; assessment application; behavioral outcome; brain cell; brain metabolism; cell type; cognitive function; conditioned fear; cytokine; extracellular; improved; insight; mouse model; neuroinflammation; novel; novel therapeutic intervention; painful neuropathy; preference; response; response to injury; tau Proteins; transcriptome; transcriptome sequencing; transcriptomics; trend

Project Summary/Abstract: Alzheimer’s disease (AD) is a devastating neurodegenerative disease with no cure. It is characterized by β- amyloid (Aβ)-containing senile plaques and tau-containing neurofibrillary tangles in the brain. Among many mechanisms contributing to AD, excessive deposition of toxic Aβ peptides is considered to play a key role. Recent studies have demonstrated that Aβ deposition in the brain triggers robust morphological and transcriptomic changes in astrocytes. How these alterations of astrocyte functions may contribute to the development of AD remains unclear. The preliminary studies of the PI’s research group show that Aβ42 induces ATP release in cultured astrocytes. Further, loss of vesicular nucleotide transporter (Vnut), which is responsible of loading cytosolic ATP into the excretory lysosomes, in astrocytes dramatically reduces Aβ plaques by ~50% and improved cognitive function in 6-month-old female 5xFAD mice. These data strongly suggest that elimination of ATP exocytosis in astrocytes blocks the accumulation of amyloid plaques and alleviates the cognitive decline. With the strong support of these exciting preliminary data, the proposed research hypothesize that Aβ deposition enhances astrocytic exocytosis of ATP, and chronic elevation of astrocyte-derived ATP further induces neuroinflammation, impairs Aβ production and clearance, and exacerbates cognitive decline. The proposed research will address this central hypothesis in specific aims: Aim 1: To examine the dynamic interaction between astrocytic exocytosis of ATP and Aβ deposition. Briefly, microdialysis will be used to assess how extracellular ATP levels in the brain are altered when Vnut is deleted in astrocytes in response to Aβ deposition. The reduced Aβ deposition could be due to decreased production or increased clearance. To this end, the relative contents of APP products, including soluble APPα, Aβ40, and Aβ42 will be quantified to assess the preference of Aβ production. In addition, Aβ-associated astrocytes and microglia will be quantified as an indicator of glial-dependent Aβ clearance. Aim 2: To assess the contributions of the astrocytic exocytosis of ATP on neuroinflammation in mouse models of AD. Neuroinflammation in 5xFAD mice without astrocytic Vnut will be examined using immunoblotting, immunofluorescence, qPCR and ELISA, and compared to appropriate control mice. In addition, to explore additional contributing mechanisms, the transcriptomes of astrocytes of these mice will be analyzed using RNA Seq and bioinformatics. Throughout the project, all the data on neuroinflammation, the extracellular ATP levels, and Aβ deposition will be correlated with the learning and memory of the same mice at 6 and 12 months of age. With a novel genetic mouse model, the proposed research will provide valuable insight into the roles of astrocytes and purinergic signaling in AD. This will help generate key preliminary data to support a more in-depth investigation in a future R01 grant. In the long term, this line of research may reveal new therapeutic approaches to treat AD and possibly other neurodegenerative diseases, by targeting purinergic signaling.

项目概要/摘要： 阿尔茨海默病（AD）是一种无法治愈的毁灭性神经退行性疾病。其特征在于β- 大脑中含有淀粉样蛋白（Aβ）的老年斑和含有tau蛋白的神经元缠结。许多 在导致AD的机制中，毒性Aβ肽的过度沉积被认为起关键作用。 最近的研究表明，Aβ沉积在大脑中触发了强大的形态学和 星形胶质细胞的转录组学变化。星形胶质细胞功能的这些改变如何有助于 AD的发展仍不清楚。PI研究小组的初步研究表明，Aβ42 在培养的星形胶质细胞中诱导ATP释放。此外，囊泡核苷酸转运蛋白（Vnut）的丢失， 在星形胶质细胞中，负责将胞浆ATP装载到排泄溶酶体中， 在6个月大的雌性5xFAD小鼠中，斑块减少约50%并改善认知功能。这些数据强烈 提示星形胶质细胞中ATP胞吐作用消除阻断了淀粉样斑块的积累， 会导致认知能力下降。在这些令人兴奋的初步数据的有力支持下， 研究假设Aβ沉积增强星形胶质细胞ATP的胞吐作用， 星形胶质细胞衍生的ATP进一步诱导神经炎症，损害Aβ的产生和清除， 会加剧认知能力的下降拟议的研究将在具体目标中解决这一中心假设： 1.研究星形胶质细胞胞吐ATP与Aβ沉积之间的动态相互作用。简言之， 微透析将用于评估当Vnut被删除时，脑中的细胞外ATP水平如何改变 星形胶质细胞对Aβ沉积的反应。Aβ沉积减少可能是由于产量减少 或增加间隙。为此，测定了APP产物的相对含量，包括可溶性APPα、Aβ40和 将定量Aβ42，以评估Aβ产生的偏好。此外，Aβ相关星形胶质细胞和 将小胶质细胞定量作为胶质细胞依赖性Aβ清除的指标。目标2：评估捐款 在AD小鼠模型中，星形胶质细胞胞吐ATP对神经炎症的影响。中的神经炎症 将使用免疫印迹、免疫荧光、qPCR和免疫荧光法检查没有星形胶质细胞Vnut的5xFAD小鼠。 ELISA，并与适当的对照小鼠进行比较。此外，为了探索其他促进机制， 将使用RNASeq和生物信息学分析这些小鼠的星形胶质细胞的转录组。在整个 在该项目中，所有关于神经炎症、细胞外ATP水平和Aβ沉积的数据都将被关联起来， 同样的小鼠在6个月和12个月大时的学习和记忆能力。通过一种新的遗传小鼠模型， 这项研究将为深入了解星形胶质细胞和嘌呤能信号在AD中的作用提供有价值的信息。 这将有助于生成关键的初步数据，以支持在未来的R 01赠款更深入的调查。在 从长远来看，这一系列的研究可能会揭示新的治疗方法来治疗AD和其他可能的疾病。 神经退行性疾病，通过靶向嘌呤能信号。