Analysis of Stem Cell Therapy in the Tremor Rat Model of Canavan Disease

描述(申请人提供)：哺乳动物大脑生发区内干细胞/祖细胞的发现导致了神经生物学领域的发展，该领域研究这些细胞修复大脑受损或病变区域的潜力。许多神经退行性疾病专门影响脑白质，因此与受影响大脑中的少突胶质细胞谱系的重建有关。我们已经确定遗传性儿童脑白质营养不良症(CD)是一种潜在的基于细胞的治疗方案。CD是由少突胶质细胞特异性酶天冬氨酸氨基转移酶(ASPA)的失活突变引起的，以中枢神经系统白质进行性减少为特征，其机制尚不清楚。我们实验室在ASPA缺失的CD动物模型中进行的研究表明，体内少突胶质细胞发育失调，最终导致晚期少突胶质细胞数量显着减少。这些研究为全面分析基于细胞的CD治疗的潜力提供了基础。这项研究旨在为这种疗法的发展提供原则证据，并将系统地分析ASPA基因缺失的震颤大鼠大脑对新生GFP转基因供体大鼠生成的神经球形成细胞进行再繁殖的接受性。我们建议将GFP转基因细胞移植到ASPA缺失的震颤大鼠体内，并使用无偏见的体视学方法分析移植细胞的植入、存活和髓鞘形成。这一分析将得到移植动物的运动表现测试的补充，从而允许就健壮、定量的体视学终点与基于细胞的治疗促进CD动物模型的表型救援之间的关系发表声明。这项研究有望提供关于特定体内微环境对这种治疗形式的接受性的有价值的数据，并将使对影响表型所需的重新髓鞘形成程度的统计有效估计成为可能。公共卫生相关性：这项提案详细介绍了一项旨在生成原则证明数据以支持加拿大疾病基于细胞的疗法的开发的研究。这项研究有望提供有价值的体内数据，以评估影响表型所需的再髓鞘程度。这项研究中收集的疗效数据将构成向FDA提交研究性新药申请的先决条件临床前研究的重要组成部分，以评估人类神经干细胞疗法在Canavan患者中的效果。

DESCRIPTION (provided by applicant): The discovery of stem/progenitor cells within germinal zones of the mammalian brain has led to the development of a field of neurobiology that deals with the potential of these cells to repair compromised or diseased regions of the brain. Many neurodegenerative diseases affect white matter specifically, and so are concerned with reconstituting the oligodendrocyte lineage in affected brains. We have identified the inherited pediatric leukodystrophy Canavan disease (CD) as a potential candidate for cell-based therapy. CD is caused by inactivating mutations to the oligodendrocyte- specific enzyme aspartoacylase (ASPA) and is characterized by a progressive decrease in CNS white matter by an as yet unknown mechanism. Studies performed in an ASPA- null animal model of CD by our laboratory have demonstrated dysregulated oligodendrocyte development in vivo that results ultimately in a significantly reduced number of late-stage oligodendrocytes. These studies provide a foundation for the comprehensive analysis of the potential of cell-based therapy for CD. The study proposed here seeks to provide proof-of-principle evidence to support the development of such a therapy, and will systematically analyze the receptivity of the ASPA-null tremor rat brain to repopulation by neurosphere-forming cells generated from neonatal GFP- transgenic donor rats that have been characterized by our laboratory. We are proposing to transplant GFP-transgenic cells into ASPA-null tremor rats and analyze transplanted cell engraftment, survival, and myelination using unbiased stereology. This analysis will be complemented by the testing of motor performance in transplanted animals, thereby allowing a statement to be made regarding the relationship between robust, quantitative stereological endpoints and the potential of cell-based therapy to promote phenotypic rescue in an animal model of CD. This study is anticipated to provide valuable data regarding the receptivity of the specific in vivo microenvironment to this form of therapy, and will enable statistically valid estimates of the degree of remyelination required to impact the phenotype. PUBLIC HEALTH RELEVANCE: This proposal details a study designed to generate proof-of-principle data to support the development of a cell-based therapy for Canavan Disease. This study is anticipated to provide valuable in-vivo data to assess the degree of remyelination required to impact the phenotype. Efficacy data collected in this study will constitute a significant part of the pre- requisite preclinical studies for submission of an Investigational New Drug Application to the FDA to evaluate the effect of a human Neural Stem Cell Therapy in Canavan patients.