Targeting the Choroid Plexus-Cerebrospinal Fluid System to Treat Post-Hemorrhagic Hydrocephalus

靶向脉络丛-脑脊液系统治疗出血后脑积水

• 批准号: 10566130
• 负责人: MARIA LEHTINEN
• 金额: $ 58.28万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2027-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10566130
• 关键词: Adult; Apical; Biology; Blood; Brain; Brain Pathology; Brain hemorrhage; Calcium; Cell secretion; Cells; Cerebral Palsy; Cerebral Ventricles; Cerebrospinal Fluid; Childhood; Choroid Plexus Epithelium; Clinical; Clinical Treatment; Data; Demyelinations; Development; Developmental Delay Disorders; Diagnostic Procedure; Drainage procedure; Embryo; Epithelial Cells; Equilibrium; Etiology; Event; Excision; Extravasation; FOS gene; Fluids and Secretions; Genetic; Goals; Hemorrhage; Home; Homeostasis; Hydrocephalus; Image; Immediate-Early Genes; Immune; Infant; Inflammatory; Infusion procedures; Intraventricular; Ions; Liquid substance; Longevity; Macrophage; Magnetic Resonance Imaging; Membrane Proteins; Modeling; Molecular; Morbidity - disease rate; Motion; Mus; Myelin; Neonatal; Neurologic Deficit; Operative Surgical Procedures; Optics; Outcome; Pathogenicity; Perinatal; Phagocytosis; Phosphorylation; Physiological; Pregnancy; Premature Infant; Process; Production; Proteins; Reaction; Repeat Surgery; Research; Resolution; Role; Route; Serial Magnetic Resonance Imaging; Severities; Signal Transduction; Site; Structure of choroid plexus; Supplementation; Surface; System; Testing; Therapeutic; Transgenic Mice; Traumatic Brain Injury; Ventricular; Viral; Water; Water Movements; absorption; blood product; brain tissue; chloride-cotransporter potassium; clinical development; clinical diagnostics; conditional knockout; experience; experimental study; extracellular; gene therapy; improved outcome; insight; intraventricular hemorrhage; long-term sequelae; mouse model; new therapeutic target; novel; overexpression; postnatal; recruit; response; therapy development; two-photon

PROJECT SUMMARY Post-hemorrhagic hydrocephalus (PHH) is a leading cause of morbidity in premature infants. PHH is triggered by germinal matrix intraventricular hemorrhage (IVH) that results in accumulation of cerebrospinal fluid (CSF) in the brain compression of surrounding brain tissue, and permanent neurological deficits. While PHH is clearly caused by an altered balance of CSF production and removal, the mechanisms are poorly understood, limiting our ability to guide rational therapies. Here, we propose to examine two processes that could be manipulated therapeutically to alleviate PHH: (1) ion and fluid transport by the choroid plexus (ChP), and (2) ventricular blood clearance by macrophages. In adults under normal physiological conditions, sheets of specialized ChP epithelial cells secrete CSF via an incompletely understood set of membrane proteins including NKCC1, a phosphorylation activated bi-directional Na-K-Cl cotransporter. Strikingly, we recently discovered that NKCC1 participates in CSF removal rather than CSF secretion during early stages of brain development. CSF-K+ levels are significantly higher in embryos than adults, likely explaining this opposite direction of NKCC1 water transport8. Experimental introduction of blood into the ventricles during development appears to further elevate CSF-K levels, and to drive intracellular calcium activity in ChP epithelial cells, expression of the immediate early gene c-fos, and increased expression/phosphorylation of NKCC1. Our findings suggest a novel counter-regulatory response to IVH in premature infants: ChP absorption of CSF via NKCC1, driven by K+. We will test this hypothesis by determining if NKCC1 activation either worsens or mitigates hydrocephalus in our mouse IVH model (Aim 1; preliminary data suggests the latter). We also found that following IVH, blood products linger in the developing ventricles and may account for the persistence of PHH. The brain's ventricles and the apical surface of the ChP are home to specific macrophages known as Kolmer cells. While Kolmer cells have been implicated as responders to brain hemorrhage, their scavenging and other functions have remained elusive. Our data suggest that during early stages of brain development, ventricular macrophages/Kolmer cells are activated and recruited to the site of blood leakage within the ventricle (Aim 2A) and that these macrophages are necessary and sufficient to clear blood and/or inflammatory signals from the ventricles (Aim 2B, C). Collectively, our data suggest that the ultimate severity of PHH depends on a developmental stage-specific interplay between blood products, ion concentrations (e.g. [K]), immune and inflammatory reactions, and NKCC1 expression levels. An estimated 20% of infants that experience intraventricular bleeds develop PHH. We suspect this is due to insufficient endogenous compensatory responses. The ultimate goal of this proposal is to improve outcomes by laying the groundwork for development of clinical treatments that boost endogenous removal of CSF and blood that drive the pathogenic processes that lead to PHH. This proposal should also guide therapies for adult IVH and other conditions with disrupted extracellular ionic homeostasis.

项目概要 出血后脑积水（PHH）是早产儿发病的主要原因。 PHH 被触发 生发基质脑室内出血（IVH）导致脑脊液（CSF）积聚 周围脑组织的脑压迫和永久性神经功能缺损。虽然 PHH 很明显 由于脑脊液产生和清除的平衡改变而引起，其机制尚不清楚，限制了 我们指导理性治疗的能力。在这里，我们建议检查两个可以操纵的过程 缓解 PHH 的治疗方法：(1) 脉络丛 (ChP) 的离子和液体运输，以及 (2) 心室血液 由巨噬细胞清除。在正常生理条件下的成人中，专门的 ChP 上皮层 细胞通过一组不完全了解的膜蛋白分泌脑脊液，其中包括 NKCC1（一种磷酸化蛋白） 激活的双向 Na-K-Cl 协同转运蛋白。引人注目的是，我们最近发现 NKCC1 参与 CSF 在大脑发育的早期阶段，脑脊液的清除而不是脑脊液的分泌。 CSF-K+ 水平显着 胚胎中的水平高于成人，这可能解释了 NKCC1 水运输的相反方向8。实验性的 在发育过程中将血液引入心室似乎会进一步提高 CSF-K 水平，并驱动 ChP 上皮细胞的细胞内钙活性、即早期基因 c-fos 的表达以及增加 NKCC1 的表达/磷酸化。我们的研究结果表明，对于 IVH 存在一种新颖的反监管反应 早产儿：ChP 通过 NKCC1 吸收 CSF，由 K+ 驱动。我们将通过确定来检验这个假设 如果 NKCC1 激活在我们的小鼠 IVH 模型中恶化或减轻脑积水（目标 1；初步数据 建议后者）。我们还发现，IVH 后，血液制品会残留在发育中的心室中，并可能 解释 PHH 的持续存在。脑室和 ChP 的顶端表面是特定物质的所在地 巨噬细胞称为科默细胞。虽然科尔默细胞被认为是大脑的反应者 出血、它们的清除功能和其他功能仍然难以捉摸。我们的数据表明，在早期 在大脑发育阶段，心室巨噬细胞/科尔默细胞被激活并招募到 心室内的血液渗漏（目标 2A），这些巨噬细胞对于清除血液是必要且充分的 来自心室的血液和/或炎症信号（目标 2B、C）。总的来说，我们的数据表明最终 PHH 的严重程度取决于发育阶段特定的血液制品、离子 浓度（例如 [K]）、免疫和炎症反应以及 NKCC1 表达水平。估计20% 经历脑室内出血的婴儿会出现 PHH。我们怀疑这是由于内源性不足造成的 补偿性反应。该提案的最终目标是通过奠定基础来改善结果 表彰其开发临床治疗方法，促进脑脊液和血液的内源性清除，从而驱动致病菌 导致 PHH 的过程。该提案还应指导成人 IVH 和其他疾病的治疗 破坏细胞外离子稳态。