Modulation of choroid plexus immuno-secretory function to restore cerebrospinal fluid homeostasis in hydrocephalus

项目摘要 最近NIH主办的脑积水研讨会强调了开发有效的 基于脉络丛上皮的非手术脑积水治疗 (CPe)及其脑脊液（CSF）分泌机制。这些知识差距使当前的 reliability CSF分流手术的发病率和失败率较高。这个提议的科学前提是 基于我们最近发表的（Nature Medicine，2017）和未发表的数据，表明CPe的免疫- 分泌可塑性在急性出血后脑积水（PHH）的发病机制中起重要作用 通过NF-κ B调节的SPAK调节的Toll样受体4（TLR4）依赖性CSF分泌增加 激酶。然而，有几个基本问题需要澄清：（i）脑室内出血如何 (IVH)引起CPe炎症？(ii)CSF高分泌需要哪些CPe离子转运蛋白 回应？(iii)这种机制是否有助于感染后脑积水（PIH）的发病机制？ (iv)药物抑制TLR4、SPAK或其他CPe靶点是否能预防或减轻IVH或感染后 脑积水？这些问题构成了我们的核心假设，即脑脊液传播的损伤-和病原体- 与IVH（高铁血红蛋白）和细菌相关的相关分子模式（DAMP和PAMP） 脑膜炎（脂多糖[LPS]），刺激TLR4/MyD88信号传导引起CPe炎症， 相关的CSF高分泌反应需要SPAK调节的CPe离子转运的功能集合 proteins.这一假设将在3个具体目标中进行检验：（1）阐明TLR4依赖性CPe炎性 （2）鉴定介导IVH的TLR4依赖性CPe离子转运效应物。 诱导的CSF高分泌;（3）表征PIH中枢细菌PAMPs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敲除大鼠在一个验证的模型， PHH，和我们的新的LPS诱导的妊高征模型，并采用直接在体内实时监测CSF 分泌;活体动物心室容积的非侵入性MR成像;定量CPe磷酸化 蛋白质组学来询问信号网络;以及药物和反义核酸的脑室内递送 寡核苷酸以调节CPe靶标。我们的研究的总体目标是确定特定的CPe炎症 和/或离子转运蛋白，其可被充分利用以预防脑积水，从而 使我们更接近消除手术分流依赖的长期目标。我们的建议是创新的 因为它挑战了现状的概念，方法和治疗方法， 脑积水如果成功的话，这项工作可能会催化我们对脑积水的看法发生变化， 从神经外科的"脑管道"障碍到药物可预防的神经炎症状况。地拓展我们的 CPe免疫分泌功能的基本了解，这项工作也可能为开发新的 与神经炎症或CSF动力学紊乱相关的其他病症的治疗策略。

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 The scientific premise of this proposal is based on our recently published (Nature Medicine, 2017) and unpublished data suggesting the CPe’s immuno- secretory plasticity plays an essential role in the pathogenesis of acute post-hemorrhagic hydrocephalus (PHH) via a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.