Arachnoid barrier breakdown in bacterial meningitis

项目概要 中枢神经系统 (CNS) 受到两个主要屏障系统的保护，即血脑屏障 (BBB) 和血脑脊液屏障（B-CSFB）。这些重要的屏障系统各自具有独特的细胞 严格调节可以进入（或退出）大脑和脑脊髓的分子和细胞的特性 液体（脑脊液）。中枢神经系统屏障也容易受到多种疾病的破坏，导致或加剧 中枢神经系统病理学。 B-CSFB 在脑膜水平破裂，脑膜是一种三层结构，包围着 大脑和脊髓，人们知之甚少。 脑膜的关键 B-CSFB 结构是蛛网膜屏障，这是一个包含上皮细胞的紧密连接 将外部脑膜硬脑膜和周围与内部软脑膜和脑脊液分开的类似层。不像 BBB 和 B-CSFB 的其他部分，对于蛛网膜屏障的敏感性知之甚少 到疾病期间崩溃。在这里，我利用 B 族链球菌 (GBS)，一种急性细菌性脑膜炎模型， 为了确定蛛网膜屏障破坏的细胞和分子机制。我将利用 结合了 Siegenthaler 实验室（中枢神经系统脉管系统和 BBB 专家）以及 Doran 实验室的知识 实验室（研究脑膜炎期间细菌与宿主相互作用的领导者），以测试细菌与宿主相互作用的假设 脑膜炎通过驱动 Snail1 依赖性上皮细胞向间充质细胞的转变来破坏细胞屏障特性 (EMT)、紧密连接和粘附连接的丧失以及功能屏障完整性受损。此外，我还要说明一下 GBS 是否直接结合原代蛛网膜屏障细胞，或者 GBS 通过炎症细胞因子发挥其作用。 这项工作的完成将通过提供新工具极大地推进中枢神经系统屏障系统领域的发展 研究蛛网膜屏障功能并对蛛网膜屏障如何分解有新的理解 疾病。我还将生成一个蛛网膜屏障细胞特性的综合模型，可以 研究了涉及脑膜的其他疾病的分解情况。这些新知识关于 蛛网膜屏障有潜力被用来设计新的方法来限制分子和细胞的交叉 蛛网膜屏障来治疗疾病，并将提供新的体外和体内理解方法 稳态和疾病期间的 B-CSFB。最后，该奖学金的拟议目标将使我 将自己发展为独立研究员所必需的概念、技术和专业培训 研究中枢神经系统障碍对中枢神经系统健康和神经系统疾病的影响。

Project Summary The central nervous system (CNS) is protected by two major barrier systems, the blood brain-barrier (BBB) and the blood-cerebrospinal fluid barrier (B-CSFB). These essential barrier systems each have unique cellular properties that tightly regulate the molecules and cells that can enter (or exit) the brain and the cerebrospinal fluid (CSF). CNS barriers are also vulnerable to breakdown in a variety of diseases, causing or exacerbating CNS pathology. The breakdown of the B-CSFB at the level of the meninges, a trilayered structure that surrounds the brain and spinal cord, is poorly understood. The critical B-CSFB structures of the meninges is the arachnoid barrier, a tight junction containing epithelial- like layer that segregates the outer meningeal dura and periphery from the inner leptomeninges and CSF. Unlike the BBB and other parts of the B-CSFB, there is very little known about the susceptibility of the arachnoid barrier to breakdown during disease. Here, I utilize Group B Streptococcus (GBS), a model of acute bacterial meningitis, in order to identify the cellular and molecular mechanisms of arachnoid barrier breakdown. I will leverage the combined knowledge of the Siegenthaler lab (experts in CNS vasculature and the BBB) as well as the Doran Lab (leaders in studying bacteria-host interactions during meningitis) in order to test the hypothesis that bacterial meningitis disrupts cellular barrier properties by driving Snail1-dependent Epithelial to Mesenchyme Transition (EMT), loss of tight and adherens junctions, and impaired functional barrier integrity. Furthermore, I will elucidate if GBS directly binds primary arachnoid barrier cells or if GBS exerts its effects through inflammatory cytokines. Completion of this work will substantially advance the field of CNS barrier systems by providing new tools to study arachnoid barrier function and a novel understanding of how the arachnoid barrier breaks down in disease. I will also generate a comprehensive model of arachnoid barrier cellular properties that can be investigated for breakdown in other diseases that involve the meninges. This new knowledge about the arachnoid barrier has the potential to be exploited to design new ways to limit crossing of molecules and cells at the arachnoid barrier to treat disease and will provide novel in vitro and in vivo approaches for understanding the B-CSFB during homeostasis and disease. Finally, the proposed goals of this fellowship will give me the conceptual, technical, and professional training necessary to develop myself as an independent researcher investigating the impact of CNS barriers on CNS health and neurological diseases.