Targeting P2RX7 Signaling as a Biomarker for ADRD

将 P2RX7 信号作为 ADRD 生物标志物

• 批准号: 10739960
• 负责人: Jason Stephen Meyer
• 金额: $ 22.28万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-20 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10739960
• 关键词: APP-PS1; Acute; Adenosine; Adult; Affect; Affinity; Age; Aging; Alzheimer' s Disease; Alzheimer' s disease related dementia; Alzheimer’s disease biomarker; Amyotrophic Lateral Sclerosis; Animal Model; Autopsy; Benzamides; Binding; Biodistribution; Biological Assay; Biological Markers; Brain; Caspase; Cause of Death; Cell Death; Cell Surface Receptors; Cell membrane; Cells; Central Nervous System; Characteristics; Chronic; Clinical Trials; Collaborations; Communication; Coupled; Data; Dementia; Development; Disease; Disease Progression; Dissociation; Effectiveness; Encephalitis; Environmental Risk Factor; Epilepsy; Exhibits; Exposure to; Female; Gene Expression; Gene Proteins; Generations; Genetic; Genetic Polymorphism; Goals; Human; IL4 gene; Image; Immune; Immune signaling; Impaired cognition; In Vitro; Inflammation; Inflammatory; Inner mitochondrial membrane; Interferon Type II; Interleukin-13; Ion Channel Gating; Kinetics; Ligands; Macrophage; Membrane Proteins; Metabolism; Microglia; Modeling; Molecular Weight; Monitor; Mus; Mutation; Nature; Nerve Degeneration; Neurodegenerative Disorders; Neuroglia; Neurons; Organ; Outer Mitochondrial Membrane; Oxidative Stress; P2X-receptor; PET/CT scan; Parkinson Disease; Penetration; Persons; Phase; Phenotype; Play; Positron-Emission Tomography; Preparation; Proteins; Public Health; Purinoceptor; Radiopharmaceuticals; Receptor Signaling; Reperfusion Injury; Research Personnel; Risk; Role; Sensitivity and Specificity; Severity of illness; Signal Transduction; Signaling Molecule; Signaling Protein; Specificity; Testing; Therapeutic; Time; Tracer; Traumatic Brain Injury; Work; antagonist; biomarker development; cell type; cohort; dosimetry; ecto-nucleotidase; extracellular; first-in-human; imaging agent; imaging study; improved; induced pluripotent stem cell; molecular marker; mouse model; neuroinflammation; novel; protein complex; protein expression; radioligand; receptor; receptor expression; recruit; response; tool; treatment response; tripolyphosphate

TITLE: Targeting P2RX7 Signaling as a Biomarker for ADRD ABSTRACT Inflammation in the brain has been proposed to be an early predictor for a range of neurodegenerative diseases such as Alzheimer’s disease (AD) and related dementias, Parkinson’s disease, ischemia-reperfusion injury, epilepsy, amyotrophic lateral sclerosis, and traumatic brain injury. Identification and development of biomarkers of neuroinflammation would permit researchers and clinicians to identify “at risk” subjects for these disorders, evaluate severity of disease stage, and effectiveness of possible treatments. Previous work on imaging agents to monitor neuroinflammation has resulted in sub-optimal radiopharmaceuticals that are only correlative in nature. To overcome these limitations, we propose to target the P2X7 receptor (P2X7R) found within the central nervous system and expressed primarily on immune cells. These receptors become activated in neurodegenerative diseases, and are an ideal target to monitor disease progression and therapy response. Previous efforts to develop ligands against this target have been stymied by the presence of P451L mutations that cause dysfunctional P2X7R signaling commonly used animal models. Recent development and characterization of a wild-derived mouse panel showed a high degree of overlap with human neuroinflammation, which is likely due to the retention of functional P2X7R, making them an ideal tool to advance ligands against this receptor. We hypothesize that neuroinflammation is a major initiator of neurodegenerative disease, where P2X7 receptors play a central role; and that developing a novel PET tracer against this receptor will enable phenotypic and therapeutic assessment during aging. Our goal is to characterize the third generation agent (i.e. [18F]GSK1482160) in human cell based assays, and in acute and chronic neuroinflammation models. In Aim 1, we will characterize [18F]-GSK14821604 in vitro in human iPSC derived microglia expressing human P2X7R (hP2X7R) in the APOEE3/E3 or APOEE4/E4 to understand: a) the radioligand depletion conditions for Ki (Aim 1.1); b) binding kinetics for kon, koff, Kd, Bmax (Aim 1.2), and Bp via saturation and association/dissociation kinetics (Aim 1.3). To understand the role of P2X7R in acute and chronic neuroinflammation, in Aim 2, we will use dynamic PET/CT in cross-sectional cohorts of female CAST/EiJ, PWK/PhJ, PWK.APP/PS1 and CAST.APP/PS1 mice. Using dynamic PET/CT we will determine the role of acute (Aim 2.2) and chronic (Aim 2.4) inflammation, where biodistribution (Aim 2.3), thus permitting allometric organ dosimetry for first in human studies. In addition, to validate the sensitivity and specificity of this ligand, (Aim 2.5) dynamic [18F]-GSK1482160 PET/CT at peak P2X7R expression will be conducted, allowing determination of maximum (CAST.APP/PS1) and non-specific (CAST.APP/PS1P2X7R-/-) binding relative to homeostatic levels of microglia (CAST/EiJ). Lastly, to establish test-retest reliability (Aim 2.6) we will repeat imaging in the same subjects separated by 1 week. In all cases, post-mortem brains will undergo Autorad and IHC ex vivo for confirmation. Combined these data will support first in human imaging studies in collaboration with the ADNI.

标题：将P2RX7信号作为ADRD的生物标志物 摘要 脑部炎症被认为是一系列神经退行性疾病的早期预测指标。 如阿尔茨海默病(AD)及相关痴呆症、帕金森氏病、缺血再灌注损伤、 癫痫、肌萎缩侧索硬化症和创伤性脑损伤。生物标志物的鉴定与发展 神经炎症的研究将使研究人员和临床医生能够确定这些疾病的“危险”受试者， 评估疾病阶段的严重程度，以及可能的治疗效果。关于显像剂的先前工作 监测神经炎症导致了次优的放射性药物，这些药物只与 大自然。为了克服这些限制，我们建议以中枢神经系统中发现的P2X7受体(P2X7R)为靶点 主要在免疫细胞上表达。这些受体在体内激活 神经退行性疾病，是监测疾病进展和治疗反应的理想目标。 之前针对该靶点开发配体的努力因P451L突变的存在而受阻 这会导致常用动物模型中的P2X7R信号失灵。最近的发展和 野生来源的小鼠面板的特征显示与人类神经炎症高度重叠， 这可能是由于保留了功能性的P2X7R，使其成为推动配体对抗的理想工具 这个感受器。我们假设神经炎是神经退行性疾病的主要始作俑者， 其中P2X7受体起核心作用；以及开发一种针对该受体的新型PET示踪剂 将在老化过程中进行表型和治疗评估。我们的目标是描述第三个 生成剂(即[18F]GSK1482160)在基于人体细胞的检测中，以及在急性和慢性中 神经炎症模型。在目标1中，我们将在体外鉴定人IPSC来源的[18F]-GSK14821604 在APOEE3/E3或APOEE4/E4中表达人P2X7R(HP2X7R)的小胶质细胞理解：a)放射性配基 KI的耗尽条件(目标1.1)；b)Kon、Koff、KD、Bmax(目标1.2)和BP通过饱和和 缔合/解离动力学(目标1.3)。了解P2X7R在急慢性疾病中的作用 神经炎症，在目标2中，我们将在女性CAST/EIJ的横断面队列中使用动态PET/CT， PWK/PhJ、PWK.APP/PS1和CAST.APP/PS1小鼠。使用动态PET/CT，我们将确定急性 (目标2.2)和慢性(目标2.4)炎症，其中生物分布(目标2.3)，从而允许异速生长器官 首次在人体研究中使用剂量学方法。此外，为了验证该配体的敏感性和特异性，(目标2.5) 将进行动态[18F]-峰值为P2X7R的GSK1482160 PET/CT，从而确定 最大(CAST.APP/PS1)和非特异性(CAST.APP/PS1P2X7R-/-)结合相对于 小胶质细胞(CAST/EIJ)。最后，为了建立重测信度(目标2.6)，我们将在相同的测试中重复成像 受试者间隔1周。在所有情况下，死后的大脑将接受Autorad和IHC体外检查 确认。将这些数据结合在一起，将支持与ADNI合作进行的第一项人体成像研究。