Wnt Signaling in Stroke

中风中的 Wnt 信号转导

• 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
• 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

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 中风中的wnt信号传导 脑内出血（ICH）是中风的最致命但研究不足的类型。治疗靶标 最小化病理过程的重点是减轻炎症和促进血肿清除率。 Wnt 信号传导调节各种细胞活性，并调节小胶质细胞的炎症反应 脑部疾病。尽管许多工作已经调查了Wnt依赖性细胞的发生，但存在着一个关键差距 尊重我们对Wnt信号如何调节ICH后炎症反应的理解。分泌的 与卷曲相关的蛋白3（SFRP3，FRZB的同义词）调节规范和非规范WNT途径， 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。但是，很少有研究研究了大脑中的SFRP3，目前对 SFRP3/Wnt信号传导在中风或ICH受伤中的作用。该R01的科学目标是调查 星形胶质细胞SFRP3是否抑制促炎反应，从而减少急性ICH损伤和改善 功能结果。通过使用多个细胞，分子，遗传学，药理，组织学和流动 细胞仪方法，我们获得了有力的证据，建议SFRP3在保护中的关键作用 早期ICH损伤：1）SFRP3表达水平在早期的围围胶质细胞中上调 ich; 2）SFRP3功能的损失/增益加剧/减轻ICH伤害； 3）SFRP3删除增加 Toll样受体（TLR）4和Wnt下游分子RhoA的表达，以及M​​MP-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预防早期的科学前提 ICH损伤，导致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信号传导和星形胶质细胞SFRP3在ICH之后通过TLR4/WNT信号传导减轻了脑损伤。在 三个具体目标，我们将确定SFRP3功能的损失/增益是否加剧/减轻ICH伤害（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（AIM 2）， 星形胶质细胞SFRP3是否通过TLR4/WNT信号通路减轻脑损伤（AIM 3）。使用 多学科方法，本研究将阐明星形胶质细胞SFRP3在ICH和细胞和细胞之后的作用 星形胶质细胞SFRP3介导的小胶质细胞表型转换的分子机制减轻了灰色和 白质损伤并改善功能恢复。这项新颖的概念验证工作具有翻译潜力 并将刺激对各种脑部疾病中SFRP3的更多研究。调查中风后的先天免疫力是 最近的Ninds-SPRG确定的关键优先级。