PICALM: Role in the pathogenesis and treatment of Alzheimer vascular blood-brain barrier clearance dysfunction, neuronal dysfunction, and amyloid-beta, tau and neurodegenerative disorders

PICALM：在阿尔茨海默病血管血脑屏障清除功能障碍、神经元功能障碍以及 β 淀粉样蛋白、tau 蛋白和神经退行性疾病的发病机制和治疗中的作用

• 批准号: 10420229
• 负责人: Berislav V Zlokovic
• 金额: $ 241.07万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-15 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10420229
• 关键词: Alleles; Alzheimer' s Disease; Alzheimer' s disease pathology; Amyloid beta-Protein; Binding; Biology; Blood - brain barrier anatomy; Blood Vessels; Brain; Brain Diseases; Cells; Clathrin Adaptors; Confocal Microscopy; Cytosol; DLG4 gene; Data; Development; Disease; Endocytosis; Endoplasmic Reticulum; Endothelial Cells; Endothelium; FDA approved; Functional disorder; Gene Delivery; Genes; Health Care Costs; Human; Impairment; In Vitro; Injury; Late Onset Alzheimer Disease; Lead; Libraries; Magnetic Resonance Imaging; Microdialysis; Microglia; Missense Mutation; Modeling; Molecular; Mus; Mutation; N-Methyl-D-Aspartate Receptors; Nerve Degeneration; Neurodegenerative Disorders; Neuronal Dysfunction; Neurons; Pathogenesis; Pathology; Pharmaceutical Preparations; Phosphatidylinositols; Play; Predisposition; Process; Proteins; Receptor Cell; Role; Synapses; System; Testing; Toxic effect; Variant; Vascular Diseases; artesunate; base; behavior test; biological adaptation to stress; density; endoplasmic reticulum stress; excitotoxicity; gene therapy; glucose-regulated proteins; in vitro Model; in vivo; induced pluripotent stem cell; insight; internal control; loss of function; mouse model; mutant; neuron loss; neuropathology; neurotoxicity; novel; novel therapeutic intervention; novel therapeutics; overexpression; response; tau Proteins; tau aggregation; trafficking; transcytosis

PICALM is one of the most significant susceptibility factors for late onset Alzheimer’s disease (LOAD). Its role in disease pathogenesis, however, remains elusive. We also do not have an effective PICALM-based therapy for AD. PICALM controls internalization of cell receptors, and intracellular trafficking of different proteins. PICALM is abundantly expressed in brain endothelium and neurons, but is reduced in LOAD and by some PICALM SNPs. To understand how PICALM regulates vascular and neuronal function and AD pathology, we developed new mouse models with PICALM-specific deletion from endothelium and neurons. The proposed studies are supported by our pilot data showing: i) that PICALM controls amyloid-β (Aβ) and tau clearance across the blood- brain barrier (BBB) and guides their trans-endothelial BBB transcytosis, and that PICALM endothelial deficiency leads to Aβ and tau brain accumulation; and ii) that PICALM loss from neurons leads to neuron loss, and renders them susceptible to both excitotoxic injury due to N-methyl-D-aspartate receptors (NMDAR) overexpression, and elevated Aβ and tau toxicity resulting from diminished PICALM binding to, and sequestration of glucose regulated protein 78 (GRP78) in the cytosol. This in turn shuttles free GRP78 to endoplasmic reticulum (ER) hampering unfolded protein response (UPR) which aggravates ER stress response to Aβ and tau. Since PICALM deficiency leads to loss-of-function, we propose to test therapies to increase PICALM with artesunate, a lead drug from our pilot FDA-approved library screen, and with gene therapy. We also generated a new Picalm465R line carrying a rare 465R PICALM missense mutation that does not alter PICALM expression, but increases its binding to GRP78 in neurons and LRP1 in endothelium. Based on our pilot data, we hypothesize that PICALM endothelial deficiency will lead to Aβ and tau brain accumulation due to their impaired clearance at the BBB caused by loss of PICALM binding to LRP1 and its deficient interactions with Rab5 and Rab11 during PICALM-guided Aβ and tau BBB transcytosis; whereas PICALM neuronal deficiency will render neurons susceptible to excitotoxic injury due to NMDAR overexpression, and will increase Aβ and tau neuronal toxicity by increasing GRP78 translocation from the cytosol to ER that will hamper UPR and augment ER stress response to Aβ and tau. Therapies to increase PICALM, and 465R mutant with enhanced binding to LRP1 and GRP78, will increase Aβ and tau BBB clearance and protect neurons. We will study the effects of endothelium-specific (AIM 1) and neuron-specific (AIM 2) PICALM deficiency on vascular and neuronal function and AD pathology; and the effects of artesunate and AAV-PHP.B-Picalm gene therapy (AIM 3), and the H465R PICALM mutation (AIM 4) on vascular and neuronal function and AD pathology. We will next identify molecular steps in Aβ and tau BBB transcytosis and neuronal toxicity regulated by PICALM using BBB models and neurons from human rs3851179 PICALM variants and Picalm465R mice (AIM 5). If successful, this proposal will generate unique new insights into PICALM biology with implications for better understanding of the role of PICALM in the pathogenesis and treatment of AD.

PICALM是晚期发作阿尔茨海默氏病（负载）最重要的易感因素之一。它的作用 然而，疾病发病机理仍然难以捉摸。我们也没有有效的基于皮卡的疗法 广告。 PICALM控制细胞受体的内在化和不同蛋白质的细胞内运输。皮基 在脑内皮和神经元中绝对表达，但在负载和某些皮基SNP中会降低。 为了了解彼皮姆如何调节血管和神经元功能和AD病理，我们开发了新的 小鼠模型具有内皮和神经元的特异性缺失。拟议的研究是 在我们的试点数据的支持下显示：i）picalm控制淀粉样蛋白-β（Aβ）和tau跨血液 - 脑屏障（BBB）并引导其跨内皮BBB转胞病，以及皮基内皮缺乏症 导致Aβ和Tau脑的积累； ii）神经元的皮基损失导致神经元丧失，并呈现 它们易受N-甲基-D-天冬氨酸受体（NMDAR）过表达引起的兴奋性毒性损伤，并且 由于皮卡结合降低而导致的Aβ和TAU毒性升高，葡萄糖调节的隔离 蛋白78（GRP78）在细胞质中。这反过 展开的蛋白质反应（UPR）加剧了对Aβ和TAU的应力反应。由于皮质缺乏 导致功能丧失，我们建议测试疗法以使用Artesunate增加果皮，这是我们的铅药物。 试验FDA批准的库屏幕以及基因治疗。我们还产生了一条携带的新的PicalM465R线 罕见的465r piticm错义突变，不会改变皮基表的表达，但增加了其与 神经元中的GRP78和内皮中的LRP1。基于我们的试点数据，我们假设皮基内皮 由于损失导致的BBB，缺乏症将导致Aβ和Tau脑的积累 与LRP1结合及其与Rab5和rab11的不足在皮卡引导的Aβ和 tau bbb transctosis;而皮基神经元缺乏会使神经元容易受到兴奋性毒性损伤 由于NMDAR的过表达，并将通过增加GRP78易位来增加Aβ和TAU神经元毒性 从细胞质到ER，会妨碍UPR并增强对Aβ和TAU的ER应力反应。治疗 增加皮卡和465R突变体，并增强与LRP1和GRP78的结合，将增加Aβ和Tau BBB 清除并保护神经元。我们将研究内皮特异性（AIM 1）和神经元特异性的影响 （AIM 2）对血管和神经元功能和AD病理学的皮基缺乏；和青铜器的影响 和AAV-PHP.B-PICALM基因疗法（AIM 3），以及H465R PICALM突变（AIM 4）在血管和血管上 神经元功能和AD病理学。接下来，我们将确定Aβ和Tau BBB跨经细胞增多症的分子步骤 由PICALM调节的神经元毒性使用人类RS3851179 PICALM变体的BBB模型和神经元调节 和PICALM465R小鼠（AIM 5）。如果成功，该提案将产生对PICALM生物学的独特新见解 有助于更好地理解picalm在AD的发病机理和治疗中的作用。