Modulation of Choroid Plexus Immuno-secretory Function to Restore Cerebrospinal Fluid Homeostasis in Hydrocephalus

项目总结 最近由美国国立卫生研究院主办的一次脑积水研讨会强调了开发有效的 基于对脉络丛上皮认识的非手术治疗脑积水 (CPE)及其脑脊液(CSF)分泌机制。这些知识鸿沟使当前 Reliance脑脊液分流术的发病率和失败率较高。这项提议的科学前提是 根据我们最近发表的(自然医学，2017)和未发表的数据表明，CPE的免疫- 分泌可塑性在急性出血性脑积水发病机制中起重要作用 通过Toll样受体-4依赖的脑脊液分泌增加受核因子-κB调节的SPAK 激活剂。然而，有几个基本问题需要澄清：(I)脑室内出血是如何 (IVH)导致CPE炎症？(Ii)脑脊液高分泌需要哪些CPE离子转运体 有什么反应？(Iii)这一机制是否有助于感染后脑积水(PIH)的发病？ (Iv)IVH或感染后抑制TLR4、SPAK或其他CPE靶点的药物能否预防或减轻感染 脑积水？这些问题构成了我们的核心假设，即脑脊液携带的损伤--以及病原体-- 与IVH(高铁血红蛋白)和细菌相关的相关分子模式(DAMPS和PAMP) 脑膜炎(脂多糖[LPS])，刺激TLR4/MyD88信号引起CPE炎症，而 相关的脑脊液高分泌反应需要SPAK调节的CPE离子转运的功能集成 蛋白质。这一假说将在3个具体目标中得到验证：(1)阐明TLR4依赖的CPE炎症 IVH触发的机制(S)；(2)确定介导IVH的依赖TLR4的CPE离子转运效应。 诱导脑脊液高分泌；以及(3)表征PIH中枢细菌PAMP对CPE的影响。 免疫分泌功能。为了做到这一点，我们将使用野生型和TLR4基因敲除大鼠在一个有效的模型 PHH和我们的新的脂多糖诱导的妊高征模型，并采用直接体内实时监测脑脊液 分泌物；活体动物脑室容量的无创性磁共振成像；定量CPE磷酸化 询问信号网络的蛋白质组学；以及脑室内药物和反义药物的传递 调节CPE靶标的寡核苷酸。我们研究的总体目标是确定特定的CPE炎症 和/或离子转运蛋白，可在药理上用于预防脑积水，从而 使我们更接近消除外科分流依赖的长期目标。我们的建议是创新的 因为它挑战了概念、方法和治疗方法的现状 脑积水。如果成功，这项工作可能会催化我们对脑积水的看法从 神经外科“大脑管道”紊乱到一种药物可预防的神经炎症状态。在推进我们的 对CPE免疫分泌功能的基本了解，这项工作也可能为小说的发展提供参考 与神经炎或脑脊液动力学紊乱相关的其他疾病的治疗策略。

PROJECT SUMMARY A recent NIH-sponsored Hydrocephalus Symposium highlighted the critical unmet need to develop effective non-surgical hydrocephalus therapies based on improved understanding of the choroid plexus epithelium (CPe) and its mechanisms of cerebrospinal fluid (CSF) secretion. These knowledge gaps perpetuate current reliance CSF shunting surgeries with high morbidity and failure rates. The scientific premise of this proposal is based on our recently published (Nature Medicine, 2017) and unpublished data suggesting the CPe’s immuno- secretory plasticity plays an essential role in the pathogenesis of acute post-hemorrhagic hydrocephalus (PHH) via a toll-like receptor-4 (TLR4)-dependent increase in CSF secretion regulated by the NF-κB-regulated SPAK kinase. However, several fundamental questions require elucidation: (i) How does intraventricular hemorrhage (IVH) cause CPe inflammation? (ii) Which CPe ion transporters are required for the CSF hypersecretory response? (iii) Does this mechanism contribute to the pathogenesis of post-infectious hydrocephalus (PIH)? (iv) Can drug inhibition of TLR4, SPAK, or other CPe targets post-IVH or infection prevent or attenuate hydrocephalus? These questions frame our central hypothesis that CSF-borne damage- and pathogen- associated molecular patterns (DAMPs and PAMPs) associated with IVH (methemoglobin) and bacterial meningitis (lipopolysaccharide [LPS]), stimulate TLR4/MyD88 signaling to cause CPe inflammation, and the associated CSF hypersecretory response requires a functional ensemble of SPAK-regulated CPe ion transport proteins. This hypothesis will be tested in 3 specific aims: (1) elucidate the TLR4-dependent CPe inflammatory mechanism(s) triggered by IVH; (2) identify the TLR4-dependent CPe ion transport effectors that mediate IVH- induced CSF hypersecretion; and (3) characterize the effects of bacterial PAMPs central to PIH on CPe immuno-secretory function. To do this, we will use wild type and TLR4 knockout rats in a validated model of PHH, and our novel LPS-induced model of PIH, and employ direct in vivo real-time monitoring of CSF secretion; non-invasive MR imaging of ventricular volume in live animals; quantitative CPe phospho- proteomics to interrogate signaling networks; and the intracerebroventricular delivery of drugs and antisense oligonucleotides to modulate CPe targets. Our study's overall objective is to identify specific CPe inflammatory and/or ion transport proteins that can be pharmacologically leveraged to prevent hydrocephalus, thereby bringing us nearer to our long-term goal of eliminating surgical shunt dependence. Our proposal is innovative because it challenges the status quo conceptual, methodological, and therapeutic approaches to hydrocephalus. If successful, this work could catalyze a change in our view of hydrocephalus from a neurosurgical “brain plumbing” disorder to a drug-preventable neuro-inflammatory condition. In advancing our basic understanding of CPe immuno-secretory function, this work may also inform development of novel therapeutic strategies for other conditions associated with neuroinflammation or disordered CSF dynamics.