Analysis of Genomic and Proteomic Changes in Glia That Lead To Hydrocephalus

描述（由申请人提供）：本研究项目的目标是确定治疗脑积水的治疗靶点。脑积水（HC）是一种主要的临床疾病，影响着美国约0.1%的人口，每年给这个国家造成超过10亿美元的损失。目前，没有基于药物的治疗方法来治疗丙型肝炎。所有HC病例均采用分流术降低心室压。超过30%的新分流器在第一年失效，超过三分之二的新分流器在十年期间失效。此外，接受分流术的丙肝患者中有2.7%死于与手术相关的并发症。尽管有这些统计数据，但治疗丙型肝炎的一般方法在50多年来并没有显著改变。在治疗丙型肝炎方面缺乏进展，在很大程度上是因为丙型肝炎的病因是多因素的，涉及基因突变和环境损害。此外，主要负责HC发展的细胞基础和分子途径在很大程度上仍然未知。已经建立了许多HC动物模型；然而，除HC外，其中大多数还伴有多种病理。因此，很难理清HC发展过程中重要的细胞机制。对人类胎儿（包括由不同突变引起的HC）的研究表明，在大多数先天性HC病例中，室管膜剥落后会发生Sylvius输水管道关闭。这些和其他研究支持这样的假设，即在大多数形式的HC中发生的早期事件是室室管膜细胞的丢失或功能障碍，并导致脑脊液的主要出口通道——脑脊液输导管的关闭。我们提出两组实验。首先，我们建议使用一种新开发的HC小鼠模型来鉴定在显性HC发展之前室管膜细胞中发生的基因组和蛋白质组学变化。这种新的HC模型，被称为Ro1HC，是基于Gi偶联GPCR在表达胶质纤维酸性蛋白（GFAP）的细胞中的过表达。我们使用四环素诱导调节系统制作了这个模型，使我们能够控制表达GFAP的细胞中基因表达的时间和水平。重要的是，在这些小鼠中观察到的病理与在人类HC中观察到的非常相似，包括早期室管膜剥脱和随后的Sylvius导水管关闭。其次，我们建议鉴定HC的体外相关物，用于筛选能够干扰HC发展或维持的小分子。

DESCRIPTION (provided by applicant):The goal of this research project is to identify therapeutic targets for the treatment of hydrocephalus. Hydrocephalus (HC) is a major clinical disorder affecting ~0.1% of the population in the United States and costing this country more than a billion dollars annually. At this time, there are no drug based therapeutic approaches for treating HC. All cases of HC are treated using shunts to decrease ventricular pressure. More than 30% of all new shunts fail in the first year and more than two thirds of new shunts fail during a ten year period. Further, 2.7 % of HC patients receiving shunts die from complications associated with the surgical procedure. In spite of these statistics, the general approach to treating HC has not changed significantly in over fifty years. The lack of progress in the treatment of HC stems, in large part, from the fact that the causes of HC are multifactorial involving both genetic mutations and environmental insults. Further, the cellular basis and molecular pathways primarily responsible for the development of HC remain largely unknown. A number of animal models of HC have been developed; however, most of these have multiple pathologies in addition to HC. As a result, it has been difficult to sort out cellular mechanisms important in the development of HC. Studies with human fetuses, which include HC arising from different mutations, suggest that ependymal denudation followed by closure of the aqueduct of Sylvius occurs in most cases of congenital HC. These and other studies support the hypothesis that an early event occurring in most forms of HC is the loss or dysfunction of ventricular ependymal cells and consequent closure of the aqueduct of Sylvius, the primary exit pathway for brain CSF. We propose two sets of experiments. First, we propose to use a newly developed mouse model of HC to identify genomic and proteomic changes that occur in ependymal cells prior to the development of overt HC. This new model of HC, referred to as Ro1HC, is based on the over expression of a Gi coupled GPCR in cells expressing glial fibrillary acidic protein (GFAP). We made this model using a tetracycline inducible regulatory system that enables us to control the timing and level of gene expression in cells expressing GFAP. Importantly, pathology observed in these mice closely resembles that observed in human HC, including the early ependymal denudation and subsequent closure of the aqueduct of Sylvius. Second, we propose to identify in vitro correlates of HC that can be used to screen for small molecules capable of interfering with the development or maintenance of HC. PUBLIC HEALTH RELEVANCE: The goal of this grant proposal is to identify the key mechanisms that lead to hydrocephalus as well as develop an in vitro correlate of hydrocephalus that can be used to screen for small molecules capable of treating this disease. Hydrocephalus is a major clinical disorder affecting ~0.1% of the population in the United States and costing this country more than a billion dollars annually. The only current treatment of hydrocephalus is based on surgically-implanting shunts designed to relieve intraventricular pressure. More than 30% of all new shunts fail in the first year and more than two thirds of shunts fail within ten years; 2.7% of hydrocephalic patients receiving shunts die from complications associated with the surgical procedure.