Wnt Signaling in Stroke

中风中的 Wnt 信号转导

• 批准号: 10436928
• 负责人: RAYMOND Charles KOEHLER
• 金额: $ 45.93万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-30 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10436928
• 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; 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; translational potential; white matter injury

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.

项目摘要 脑卒中中的Wnt信号转导 脑出血（ICH）是最致命但研究不足的中风类型。治疗靶点 减少病理过程的重点是减轻炎症和促进血肿清除。Wnt 信号调节不同的细胞活动，并调节某些神经元中小胶质细胞的炎症反应。 脑部疾病。尽管已经有很多工作研究了Wnt依赖的细胞发生，但与Wnt依赖的细胞发生之间存在着关键的差距。 这与我们对Wnt信号如何调节脑出血后炎症反应的理解有关。分泌的 卷曲相关蛋白3（sFRP 3，Frzb的同义词）调节经典和非经典Wnt途径， 并且sFRP 3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sFRP 3在大脑中的作用，并且目前对sFRP 3的作用知之甚少。 sFRP 3/Wnt信号在脑卒中或ICH损伤中的作用本R 01的科学目的是研究 星形胶质细胞sFRP 3是否抑制促炎反应，从而减少急性ICH损伤， 功能性成果。通过使用多个细胞，分子，遗传，药理学，组织学和流动 细胞计数方法，我们已经获得了强有力的证据，表明sFRP 3在保护免受 早期脑出血损伤：1）sFRP 3表达水平在血肿周围区域的星形胶质细胞中上调， ICH; 2）sFRP 3功能的丧失/获得加剧/减轻ICH损伤;和3）sFRP 3缺失增加 Toll样受体（TLR）4和Wnt下游分子RhoA的表达，以及MMP-9在肿瘤细胞中的活性。 脑出血。这些新的观察结果支持了星形胶质细胞sFRP 3保护早期免疫的科学前提。 脑出血损伤，使我们假设星形胶质细胞sFRP 3通过抑制小胶质细胞M2极化， 脑出血后星形胶质细胞sFRP 3通过TLR 4/Wnt信号通路减轻脑损伤。在 三个具体的目标，我们将确定sFRP 3功能的丧失/获得是否加重/减轻ICH损伤（Aim 1）星形胶质细胞sFRP 3是否通过抑制TLR 4信号传导促进小胶质细胞M2极化（Aim 2）， 以及星形胶质细胞sFRP 3是否通过TLR 4/Wnt信号通路减轻脑损伤（Aim 3）。使用 通过多学科的方法，本研究将阐明星形胶质细胞sFRP 3在脑出血后的作用， 星形胶质细胞sFRP 3介导的小胶质细胞表型转换减轻灰色和 白色物质损伤，促进功能恢复。这项新颖的概念验证工作具有转化潜力 并将刺激更多sFRP 3在各种脑部疾病中的研究。研究中风后的先天免疫是 这是最近的NINDS-SPRG确定的一个关键优先事项。