Wnt Signaling in Stroke

中风中的 Wnt 信号转导

基本信息

批准号：
10197237
负责人：
RAYMOND Charles KOEHLER
金额：
$ 46.34万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-09-30 至 2023-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10197237
关键词：
Acute Acute Brain Injuries Affect Agonist Anti-Inflammatory Agents Antidepressive Agents Astrocytes Astrocytoma Attenuated Autologous Blood Blood Cells Brain Brain Diseases Brain Injuries Brain hemorrhage Calcium Cell physiology Cells Cerebral hemisphere hemorrhage Cytoplasmic Granules Degenerative polyarthritis Electron Microscopy Fluorescence-Activated Cell Sorting Gelatinase A Gelatinase B Green Fluorescent Proteins Heart failure Hematoma Hemoglobin Hippocampus (Brain)Histologic Histology Immune Inflammation Inflammatory Response Injury Knock-out Knockout Mice Lead Magnetic Resonance Imaging Mediating Methods Microglia Modeling Molecular Molecular Genetics Monomeric GTP-Binding Proteins Mus Myeloid Cells National Institute of Neurological Disorders and Stroke Natural Immunity Outcome Pathologic Pathologic Processes Pathway interactions Phagocytosis Pharmacology Phenotype Pilot Projects Proteins Publishing Recombinants Recovery of Function Research Rho-associated kinase Role Secondary to Signal Pathway Signal Transduction Signaling Protein Slice Stroke TLR4 gene Testing Thrombin Transgenic Mice WNT Signaling Pathway Whole Blood Wild Type Mouse Work beta catenin blood-brain barrier disruption brain cell dentate gyrus effective therapy frizzled related protein-3 functional outcomes gray matter improved improved outcome in vivo inflammatory marker inhibitor/antagonist injury recovery interdisciplinary approach mRNA Expression macrophage neurobehavioral test novel planar cell polarity post stroke protective effect pup recruit response rho rho GTP-Binding Proteins therapeutic target white matter injury

项目摘要

Project Summary Wnt signaling in stroke Intracerebral hemorrhage (ICH) is the most lethal but under-researched type of stroke. Therapeutic targets to minimize pathologic processes focus on mitigating inflammation and promoting hematoma clearance. Wnt signaling regulates diverse cellular activities and modulates an inflammatory response in microglia in certain brain diseases. Although much work has investigated Wnt-dependent cell genesis, a critical gap exists with respect to our understanding of how Wnt signaling regulates inflammatory responses after ICH. The secreted frizzled-related protein 3 (sFRP3, a synonym of Frzb) regulates both canonical and noncanonical Wnt pathways, and dysregulation of sFRP3 is associated with certain pathologic conditions, including osteoarthritis, astrocytoma, and heart failure. However, very few studies have investigated sFRP3 in brain, and little is currently known about the role of sFRP3/Wnt signaling in injury from stroke or ICH. The scientific objective of this R01 is to investigate whether astrocyte sFRP3 inhibits proinflammatory response, thereby reducing acute ICH injury and improving functional outcomes. By using multiple cellular, molecular, genetic, pharmacologic, histologic, and flow cytometric methods, we have obtained strong evidence to suggest a key role for sFRP3 in protection against early ICH injury: 1) sFRP3 expression level is upregulated in astrocytes in the perihematomal region early after ICH; 2) Loss/gain of sFRP3 function exacerbates/mitigates ICH injury; and 3) sFRP3 deletion increases expression of Toll-like receptor (TLR)4 and Wnt downstream molecule RhoA, as well as MMP-9 activity in the ICH brain. These novel observations support the scientific premise that astrocyte sFRP3 protects against early ICH injury and led us to hypothesize that astrocyte sFRP3 promotes microglial M2 polarization through inhibition of TLR4 signaling and that astrocyte sFRP3 attenuates brain damage through TLR4/Wnt signaling after ICH. In three specific aims, we will determine whether loss/gain of sFRP3 function exacerbates/mitigates ICH injury (Aim 1), whether astrocyte sFRP3 promotes microglial M2 polarization through inhibition of TLR4 signaling (Aim 2), and whether astrocyte sFRP3 attenuates brain injury through the TLR4/Wnt signaling pathway (Aim 3). Using multidisciplinary approaches, this study will elucidate the role of astrocyte sFRP3 after ICH and the cellular and molecular mechanisms by which astrocyte sFRP3-mediated microglial phenotypic switching mitigates gray and white matter injury, and improves functional recovery. This novel proof-of-concept work has translational potential and will stimulate more studies of sFRP3 in various brain diseases. Investigating innate immunity after stroke is a critical priority identified by the recent NINDS-SPRG.

项目概要中风中的 Wnt 信号传导脑出血（ICH）是最致命但研究不足的中风类型。治疗目标为最大限度地减少病理过程，重点是减轻炎症和促进血肿清除。 Wnt 信号传导调节多种细胞活动并在某些情况下调节小胶质细胞的炎症反应脑部疾病。尽管许多工作已经研究了 Wnt 依赖性细胞的发生，但仍存在关键差距尊重我们对 Wnt 信号如何调节 ICH 后炎症反应的理解。所分泌的卷曲相关蛋白 3（sFRP3，Frzb 的同义词）调节经典和非经典 Wnt 通路， sFRP3 的失调与某些病理状况有关，包括骨关节炎、星形细胞瘤、和心力衰竭。然而，很少有研究调查大脑中的 sFRP3，目前对它知之甚少。 sFRP3/Wnt 信号传导在中风或脑出血损伤中的作用。 R01 的科学目标是研究星形胶质细胞sFRP3是否抑制促炎反应，从而减轻急性ICH损伤并改善功能结果。通过使用多种细胞、分子、遗传、药理学、组织学和流式细胞技术通过细胞计数方法，我们获得了强有力的证据表明 sFRP3 在预防早期 ICH 损伤：1) 损伤后早期血肿周围区域星形胶质细胞中 sFRP3 表达水平上调 ICH； 2) sFRP3功能的丧失/增强会加剧/减轻ICH损伤； 3) sFRP3 缺失增加 Toll 样受体 (TLR)4 和 Wnt 下游分子 RhoA 的表达以及 MMP-9 活性 ICH 大脑。这些新颖的观察结果支持了星形胶质细胞 sFRP3 可以预防早期 ICH 损伤并使我们假设星形胶质细胞 sFRP3 通过抑制促进小胶质细胞 M2 极化 TLR4 信号传导的影响以及星形胶质细胞 sFRP3 在 ICH 后通过 TLR4/Wnt 信号传导减轻脑损伤。在三个具体目标，我们将确定 sFRP3 功能的丧失/增强是否会加剧/减轻 ICH 损伤（Aim 1)、星形胶质细胞 sFRP3 是否通过抑制 TLR4 信号传导促进小胶质细胞 M2 极化（目标 2），星形胶质细胞 sFRP3 是否通过 TLR4/Wnt 信号通路减轻脑损伤（目标 3）。使用通过多学科方法，本研究将阐明 ICH 后星形胶质细胞 sFRP3 的作用以及细胞和星形胶质细胞 sFRP3 介导的小胶质细胞表型转换减轻灰色和白质损伤，并改善功能恢复。这项新颖的概念验证工作具有转化潜力并将刺激更多关于 sFRP3 在各种脑部疾病中的研究。研究中风后的先天免疫是最近的 NINDS-SPRG 确定了一个关键优先事项。