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

基本信息

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
项目类别：
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&apos s Disease Alzheimer&apos s disease brain Alzheimer&apos 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

项目摘要

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.

项目摘要/摘要：阿尔茨海默病（AD）是一种无法治愈的破坏性神经退行性疾病，其特点是β-。大脑中含有淀粉样蛋白 (Aβ) 的老年斑和含有 tau 蛋白的神经原纤维缠结是其中之一。在导致 AD 的机制中，有毒 Aβ 肽的过度沉积被认为起着关键作用。最近的研究表明，Aβ 在大脑中的沉积会引发强大的形态学和星形胶质细胞的转录组变化。星形胶质细胞功能的这些改变如何有助于 PI研究小组的初步研究表明Aβ42的发生发展尚不清楚。诱导培养的星形胶质细胞中 ATP 的释放，此外，还导致囊泡核苷酸转运蛋白 (Vnut) 的损失。负责将胞浆 ATP 加载到排泄溶酶体中，在星形胶质细胞中显着减少 Aβ 6 个月大的雌性 5xFAD 小鼠的斑块减少了约 50%，认知功能得到改善。表明星形胶质细胞中 ATP 胞吐作用的消除可阻止淀粉样斑块的积累，在这些令人兴奋的初步数据的有力支持下，该提议缓解了认知能力下降。研究发现，Aβ 沉积可增强星形细胞的 ATP 胞吐作用，并且慢性升高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，并且加剧认知能力下降。拟议的研究将解决这一中心假设的具体目标：目标。图 1：检查星形细胞 ATP 胞吐作用和 Aβ 沉积之间的动态相互作用。微透析将用于评估当 Vnut 被删除时大脑中细胞外 ATP 水平如何改变星形胶质细胞中对 Aβ 沉积的反应 Aβ 沉积减少可能是由于产量减少所致。为此，APP 产品的相对含量，包括可溶性 APPα、Aβ40 和 Aβ42 将被量化以评估 Aβ 产生的偏好。此外，Aβ 相关星形胶质细胞和小胶质细胞将被量化为胶质依赖性 Aβ 清除的指标。目标 2：评估贡献。 AD 小鼠神经炎症模型中 ATP 星形细胞胞吐作用的影响。将使用免疫印迹、免疫荧光、qPCR 和 ELISA，并与适当的对照小鼠进行比较此外，为了探索其他贡献机制，这些小鼠的星形胶质细胞的转录组将使用 RNA 测序和生物信息学进行分析。该项目中，所有关于神经炎症、细胞外 ATP 水平和 Aβ 沉积的数据都将相互关联具有与 6 个月和 12 个月大的小鼠相同的学习和记忆能力这项研究将为了解星形胶质细胞和嘌呤信号在 AD 中的作用提供有价值的见解。这将有助于生成关键的初步数据，以支持未来 R01 资助中更深入的调查。从长远来看，这方面的研究可能会揭示治疗 AD 和其他可能的疾病的新治疗方法通过靶向嘌呤能信号传导来治疗神经退行性疾病。