Stem Cell Transplantation for Neurogenetic Disease

描述（由申请人提供）：遗传性代谢紊乱导致大量脑部疾病。治疗这类疾病的主要障碍是缺陷的固有性质导致中枢神经系统内病理病变的全局分布。这种情况需要在整个中枢神经系统或病理后果最严重的关键区域对细胞进行纠正。在这项资助中，我们将研究基于神经干细胞（NSC）的方法，通过在大脑内传递扩散蛋白来治疗神经遗传性疾病的中枢神经系统（CNS）。该方法是在体外对NSCs中的缺陷进行基因校正，然后将校正后的细胞移植回有缺陷的大脑。在适当的情况下，NSCs可以在大脑内迁移并分化成所有三种主要的脑细胞谱系。作为测试系统，我们将使用B-葡萄糖醛酸酶（GUSB）缺陷小鼠，这是人类溶酶体贮积病（LSD）的模型。有50个lsd个体，大约20%的影响中枢神经系统的遗传性儿童遗传疾病是由lsd引起的。原则上，一种常见的治疗策略可以用于90%的LSD。它是基于这样的观察：溶酶体酶可以从基因校正的细胞中分泌出来，在组织中扩散，并且可以被突变细胞吸收以恢复缺失的酶活性。因此，仅将改良的NSC输送到大脑的一小部分可能就能挽救大量的脑组织。为了实现治疗酶的整体递送，移植细胞需要分散在大脑的三维空间内。我们已经证明基因治疗可以在使用克隆细胞系的gusb缺陷小鼠的大脑中起作用。然而，要实现永久和完全的矫正，特别是要达到更大的人类大脑的整体病变，存在着实质性的障碍。我们拟研究：1)将小鼠NSC的移植特性和载体基因表达作为自体校正（体内基因治疗）的模型；2)增加NSC远离注射部位迁移的潜在策略；3)治疗对神经病理的影响及移植受者的安全性。在了解NSC的移植特性以治疗该模型方面的进展应该适用于所有类型的疾病。

DESCRIPTION (provided by applicant): Inherited metabolic disorders cause a significant number of brain diseases. A major barrier to treating such diseases is that the inherent nature of the defect results in global distribution of the pathologic lesions within the CNS. This circumstance requires that cells be corrected either throughout the CNS or in key areas where the pathologic consequences are most severe. In this grant we will investigate neural stem cell (NSC)-based approaches to treat the central nervous system (CNS) in neurogenetic disease by delivering a diffusible protein within the brain. The approach is to genetically correct the defect in NSCs in vitro and transplant the corrected cells back into the defective brain. Under the right circumstances, NSCs can migrate within the brain and differentiate into all three major lineages of brain cells. As a test system, we will use a B- glucuronidase (GUSB) deficient mouse, which is a model for human lysosomal storage diseases (LSD). There are >50 individual LSDs and they are responsible for approximately 20% of all inherited childhood genetic diseases that affect the CNS. A common treatment strategy can be used, in principle, for >90% of the LSD's. It is based on the observation that lysosomal enzymes can be secreted from genetically corrected cells, diffuse through tissue, and can be taken up by mutant cells to restore the missing enzymatic activity. Thus, delivery of the modified NSC's to only a fraction of the brain may be able to rescue a large amount of brain tissue. To achieve global delivery of the therapeutic enzyme, the transplanted cells need to be dispersed within the three dimensional space of the brain. We have demonstrated that gene therapy can work in the brains of the GUSB-deficient mice using a clonal cell line. However, there are substantial barriers to achieving permanent and complete correction, particularly in reaching the global lesions in the much larger human brain. We propose to investigate: 1) the transplantation properties and vector gene expression in primary murine NSC's as a model for autologous correction (en vivo gene therapy); 2) potential strategies to increase the migration of the NSC's away from the injection site; and 3) the effectiveness of the treatment on the neuropathology and the safety of the transplant recipients. Advances in understanding the transplantation properties of NSC's for treatment in this model should have applicability to the whole class of disease.