Stem Cell Transplantation for Neurogenetic Disease

描述(申请人提供)：遗传性代谢紊乱会导致大量的脑部疾病。治疗这类疾病的一个主要障碍是缺陷的固有性质导致病理损害在中枢神经系统内的全球分布。这种情况要求在整个中枢神经系统或在病理后果最严重的关键区域纠正细胞。在这笔赠款中，我们将研究基于神经干细胞(NSC)的方法，通过在大脑中传递可扩散的蛋白质来治疗神经遗传性疾病中的中枢神经系统(CNS)。方法是在体外对神经干细胞的缺陷进行基因纠正，并将纠正后的细胞移植回有缺陷的大脑中。在适当的情况下，神经干细胞可以在大脑内迁移，并分化为所有三种主要的脑细胞。作为测试系统，我们将使用B-葡萄糖醛酸酶(GUSB)缺陷小鼠，这是人类溶酶体储存疾病(LSD)的模型。有50个个体LSD，在所有影响中枢神经系统的遗传性儿童遗传病中，约有20%是由LSD引起的。原则上，90%的LSD可以使用一种常见的治疗策略。它是基于观察到的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，并可以被突变细胞吸收，以恢复缺失的酶活性。因此，只将改良的神经干细胞输送到大脑的一小部分可能能够挽救大量的脑组织。为了实现治疗酶的全球输送，移植的细胞需要分散在大脑的三维空间内。我们已经使用克隆细胞系证明了基因治疗可以在GUSB缺陷小鼠的大脑中发挥作用。然而，要实现永久和完全的矫正，特别是在到达更大的人脑中的全局病变方面，存在着实质性的障碍。我们建议研究：1)作为自体矫正(体内基因治疗)模型的原代小鼠神经干细胞的移植特性和载体基因表达；2)增加神经干细胞从注射部位迁移的潜在策略；3)治疗对神经病理学和移植受者安全性的有效性。在这一模型中，对神经干细胞移植特性的理解的进展应该适用于整个疾病类别。

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.