Meningeal Mast Cells: Key effectors of stroke pathology

脑膜肥大细胞：中风病理学的关键效应器

• 批准号: 8623155
• 负责人: GARY K STEINBERG
• 金额: $ 23.37万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-03-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8623155
• 关键词: Address; Adverse effects; Affect; Brain; Brain Edema; Brain Injuries; Brain Pathology; C5a anaphylatoxin receptor; Cell physiology; Cells; Complement; Data; Development; Diphtheria Toxin; Disease; Drug Targeting; Effector Cell; Encephalitis; Engraftment; Enzymes; Event; Evolution; Fc Receptor; Goals; IL6 gene; Immune; Immunotherapy; In Vitro; Inflammation; Inflammatory; Injection of therapeutic agent; Intrathecal Injections; Knock-in Mouse; Knockout Mice; Lesion; Measures; Mediating; Mediator of activation protein; Meningeal; Meninges; Modeling; Molecular; Molecular Mechanisms of Action; Mus; Outcome; Pathology; Pathway interactions; Play; Process; Recovery; Relative (related person); Reporting; Role; Site; Spleen; Stroke; Surface; Testing; Therapeutic; Tissues; Transgenic Mice; Wild Type Mouse; cytokine; diphtheria toxin receptor; disability; effective therapy; gain of function; immunoregulation; improved; injured; innovation; loss of function; mast cell; mast cell protease 4; mouse model; neutrophil; new therapeutic target; novel; novel therapeutics; post stroke; public health relevance; receptor; repaired; response; selective expression; therapeutic target; tool

DESCRIPTION (provided by applicant): Stroke, a leading cause of serious long-term disability in the US, is in need of therapeutics that reduce damage and promote recovery. Post-stroke inflammation is a critical determinant of damage and recovery and is thus a promising therapeutic target. Mast cells (MCs), which play critical roles in the development of inflammatory processes in other pathologies, were recently ascribed a role in the exacerbation of post-stroke brain inflammation and damage. This suggests that MCs could be key determinants of stroke-induced inflammation and hence are an attractive therapeutic target. The primary focus of this proposal is to elucidate the mechanism of action of mast cells in exacerbating stroke pathology, with the long-term goal of identifying novel therapeutic strategies for stroke. Our overall hypothesis is that mast cells residing in the meninges are key effectors of stroke pathology. This is tested in Aim 1 using two different approaches. The gain-of-function approach (Aim 1a) uses a "mast cell knock-in mouse" model in which the MC-deficiency of genetically MC- deficient mice is selectively repaired by engraftment of in vitro grown mast cells. Direct engraftment of MCs into the meninges of these MC-deficient mice will determine the involvement of meningeal-located MCs in stroke pathology. This is complemented by the loss-of-function approach (Aim1b) where meningeal MCs are depleted by meningeal injection of diphtheria toxin (DT) into a novel mouse model that selectively expresses the DT receptor on MCs. Together, innovative use of these mouse models enables us to determine if meningeal MCs are necessary and sufficient for the detrimental effects of MCs after stroke. Aim 2 addresses the molecular mechanism of action of MCs using the mast cell knock-in mouse model. Through engraftment of MCs from various receptor knock-out mice we will investigate the mechanism of meningeal MC activation (Aim 2a), and by engraftment of MCs from cytokine knock-out mice we will identify mast cell-secreted factors important for the downstream effects of MCs on stroke pathology (Aim 2b). Identifying a crucial role for meningeal MCs after stroke will highlight the importance o the meninges in modulating brain pathology. As the meninges are relatively accessible (e.g., by intrathecal injection) this concept could potentially present a new strategy for stroke therapeutic that may overcome the hurdle of targeting drugs to the injured brain and reduce unwanted side effects of systemic immunomodulation. Furthermore, by establishing the mechanism of action of MCs we begin to delineate the molecular pathways involved in modulating the response to stroke, an essential step to finding novel therapeutic targets. Together, our proposed studies address significant gaps in the understanding of post-stroke inflammatory events that contribute to stroke pathology and may identify new strategies for stroke therapeutics.

描述（由申请人提供）：中风是美国严重长期残疾的主要原因，需要减少损伤和促进康复的治疗方法。卒中后炎症是损伤和恢复的关键决定因素，因此是有希望的治疗靶点。肥大细胞（MC），在其他病理学中的炎症过程的发展中发挥关键作用，最近被归因于中风后脑炎症和损伤的恶化中的作用。这表明MC可能是中风诱导的炎症的关键决定因素，因此是一个有吸引力的治疗靶点。该提案的主要重点是阐明肥大细胞在加重卒中病理中的作用机制，长期目标是确定卒中的新治疗策略。我们的总体假设是，驻留在脑膜中的肥大细胞是中风病理学的关键效应器。目标1使用两种不同的方法对此进行了测试。功能获得方法（Aim 1a）使用“肥大细胞敲入小鼠”模型，其中遗传性MC缺陷小鼠的MC缺陷通过植入体外生长的肥大细胞来选择性修复。将MC直接植入这些MC缺陷小鼠的脑膜中将确定位于脑膜的MC在中风病理学中的参与。这是补充功能丧失的方法（Aim1b），其中脑膜MCs耗尽脑膜注射白喉毒素（DT）到一个新的小鼠模型，选择性地表达DT受体的MCs。总之，这些小鼠模型的创新使用使我们能够确定脑膜MCs是否是中风后MCs有害作用的必要和充分条件。目的2：利用肥大细胞基因敲入小鼠模型，探讨肥大细胞作用的分子机制。通过植入来自各种受体敲除小鼠的MC，我们将研究脑膜MC活化的机制（目的2a），通过植入来自细胞因子敲除小鼠的MC，我们将鉴定对MC对中风病理学的下游作用重要的肥大细胞分泌因子（目的2b）。确定脑卒中后脑膜MC的关键作用将突出脑膜在调节脑病理学中的重要性。由于脑膜相对容易接近（例如，通过鞘内注射），这一概念可能为中风治疗提供一种新的策略，其可以克服将药物靶向受伤的大脑的障碍，并减少系统性免疫调节的不希望的副作用。此外，通过建立MCs的作用机制，我们开始描绘参与调节对卒中的反应的分子途径，这是寻找新的治疗靶点的重要步骤。总之，我们提出的研究解决了在理解卒中后炎症事件方面的重大差距，这些炎症事件有助于卒中病理学，并可能确定卒中治疗的新策略。