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.

项目摘要 杀伤后脑积水（PHH）是早产儿发病的主要原因。 PHH触发 通过生发基质室内出血（IVH），导致脑脊液（CSF）积累 周围脑组织的大脑压缩和永久性神经系统缺陷。虽然PHH显然是 由于CSF的产生和去除的平衡改变引起的，这些机制的理解很少，限制 我们指导理性疗法的能力。在这里，我们建议检查两个可以操纵的过程 治疗以减轻PHH：（1）脉络丛（CHP）的离子和液体转运，（2）心室血液 巨噬细胞清除。在正常生理条件下的成年人中，专门的CHP上皮床单 细胞通过不完全理解的一组膜蛋白（包括NKCC1）（一种磷酸化）分泌CSF 活性双向Na-K-Cl共转运蛋白。令人惊讶的是，我们最近发现NKCC1参与了CSF 在大脑发育的早期阶段去除而不是CSF分泌。 CSF-K+水平显着 胚胎的胚胎高于成年人，可能解释了NKCC1水运输的这一方向8。实验 发育过程中将血液引入心室似乎进一步提高了CSF-K水平，并驱动 CHP上皮细胞中的细胞内钙活性，直接早期基因C-FOS的表达，并增加 NKCC1的表达/磷酸化。我们的发现暗示了对IVH的新颖的反调节反应 早产婴儿：通过K+驱动的NKCC1吸收CSF的CHP。我们将通过确定 如果NKCC1激活在我们的鼠标IVH模型中恶化或减轻脑积水（AIM 1;初步数据 建议后者）。我们还发现，随着IVH，血液产物在发育中的心室中徘徊，可能 解释PHH的持续性。大脑的心室和CHP的顶表面是特定的家园 巨噬细胞称为科尔默细胞。虽然科尔默细胞被牵涉到大脑的反应者 出血，清除和其他功能仍然难以捉摸。我们的数据表明在早期 大脑发育阶段，心室巨噬细胞/科尔默细胞被激活并招募到该部位 心室内的血液泄漏（AIM 2A），这些巨噬细胞是必要的，足以清除 来自心室的血液和/或炎症信号（AIM 2B，C）。总的来说，我们的数据表明最终 PHH的严重程度取决于血液产物，离子之间的发育特异性相互作用 浓度（例如[K]），免疫和炎症反应以及NKCC1表达水平。估计有20％ 经历脑室内出血的婴儿中会出现PHH。我们怀疑这是由于内源性不足所致 补偿性反应。该提议的最终目标是通过奠定基础来改善结果 为了开发临床治疗，可以增加内源性去除CSF和血液，以驱动致病性 导致PHH的过程。该建议还应指导成人IVH和其他条件的疗法 破坏细胞外离子稳态。