Disease Mechanisms of Prenatal and Pediatric Acquired Hydrocephalus

摘要 细菌和病毒感染都与小儿脑积水有关， 大脑的发育程序。在胎儿发育中，干细胞排列在心室中，提供神经元和 脑发育所需的神经胶质细胞;心室接触干细胞也产生保护性上皮细胞 单层室管膜细胞。室管膜细胞沿着心室形成屏障， 细胞被转移到室管膜下区，仅保留一个薄的顶突与大脑皮层接触， 脊髓液这种独特的排列表征了干细胞龛沿着外侧壁的特征。 心室和支持出生后发育中的持续神经发生。众所周知，某些病毒 优先靶向心室的室管膜细胞衬里，导致结构支持和屏障的丧失 室管膜细胞的功能。室管膜发生和神经发生期间的感染 将严重影响干细胞生态位的发育和功能。 该提案的前提是以受控的方式模拟感染，并描述 感染后心室-室管膜下区干细胞龛的修复机制 脑积水先前的工作绘制了3D（小鼠和人类）侧脑室以确定体积， 表面积和曲率在显影过程中发生变化。谱系追踪的新数据（多色 载体）和活细胞成像将记录干细胞介导的室管膜发生与神经发生， 解决正常发育中的干细胞耗竭问题（目标1）。扩大的脑室 （脑积水）影响干细胞生态位功能和损害神经发生将首先使用 流感的神经毒性成分神经氨酸酶，已知其在小鼠中引起脑积水（Aim 2）。 在胚胎和出生后小鼠脑室内注射神经氨酸酶后， 将检查脑积水、关键发育时间点和干细胞介导的修复潜力。 在检查了单变神经氨酸酶脑积水模型后， 将使用流感的小鼠变体对脑积水进行建模（目的3）。脑室内、胎盘内和 将评估鼻内途径，并评估对心室-心室下干细胞生态位及其 功能将被检查。假设流感的诱导和严重程度引起感染后 还将测试可通过先前的同源或异源免疫来减轻脑积水。这些研究 将定义感染后脑积水对关键干细胞生态位的影响， 再生修复-感染后脑积水的指导治疗策略。

Abstract Infections, both bacterial and viral, have been linked to pediatric hydrocephalus and can impact the nascent brain’s developmental programs. In fetal development, stem cells line the ventricles and provide neurons and glia required for brain development; ventricle-contacting stem cells also generate a protective epithelial monolayer of ependymal cells. As ependymal cells form a barrier wall along the ventricles, the remaining stem cells are relegated to the subependymal zone and retain only a thin apical process in contact with the cerebral spinal fluid. This unique arrangement characterizes the stem cell niche along the lateral walls of the lateral ventricle and supports continued neurogenesis in postnatal development. It is known that certain viruses preferentially target the ependymal cell lining of the ventricles resulting in loss of the structural support and barrier functions provided by the ependymal cells. Infection during periods of ependymogenesis and neurogenesis would critically impact the development and function of the stem cell niche. The premise of this proposal is to model infection in a controlled manner and characterize damage to, and reparative mechanisms of, the ventricular-subventricular zone stem cell niche over the course of post-infectious hydrocephalus. Previous work mapped the lateral ventricles in 3D (mouse and human) to determine volume, surface area and curvature changes over the course of development. New data from lineage tracing (multi-color vectors) and live cell imaging will document stem cell-mediated ependymogenesis versus neurogenesis and address stem cell depletion in normal development (Aim 1). The hypothesis that enlarged ventricles (hydrocephalus) impact stem cell niche functions and compromise neurogenesis will first be tested using a neurovirulent component of influenza, neuraminidase, which is known to cause hydrocephalus in mice (Aim 2). After intraventricular injection of neuraminidase in embryonic and postnatal mice, sequelae of post-infectious hydrocephalus, critical developmental time points and potential for stem cell-mediated repair will be examined. Following examination of a univariant, neuraminidase, hydrocephalus model, bona fide post-infectious hydrocephalus using a mouse variant of influenza will be modeled (Aim 3). Intraventricular, intraplacental and intranasal routes will be assessed and the impact on the ventricular-subventricular stem cell niche and its functions will be examined. The hypothesis that induction and severity of influenza-induced post-infectious hydrocephalus can be mitigated by prior homologous or heterologous immunity will also be tested. These studies will define the impact that post-infectious hydrocephalus has on a critical stem cell niche and its capacity for regenerative repair – guiding treatment strategies for post-infectious hydrocephalus.