Gene transfer & NMR studies in alpha-mannosidosis brain

描述（由申请人提供）：溶酶体贮积病是一组遗传性酶缺陷，可产生致命的退行性综合征，其中大多数影响中枢神经系统。神经干细胞移植和小鼠疾病模型直接基因转移的研究表明，提供正常酶可以显著减少病理。然而，影响中枢神经系统的代谢性疾病通常具有全局性病变，并且大脑内的基因传递相对有限，特别是在大型哺乳动物中。我们已经证明，将AAV2载体注射到小鼠脑实质中导致局部转导，但可以通过分泌介导正常酶的广泛分布。通过受体介导的内吞作用，介导了远离转导部位的细胞中储存病变的纠正。我们最近发现，将AAV2注入新生小鼠脑侧脑室后，载体通过脑脊液循环广泛分布，导致基因表达播散。在这个项目中，我们将研究一种遗传性的酸性α - d -甘露糖苷酶（MANB）缺乏，它会导致细胞溶酶体中积累未降解的富含甘露糖的低聚糖，特别是在中枢神经系统（CNS）中，导致智力迟钝和其他异常。我们研究了人类疾病的猫模型的遗传学、生物化学和病理学，这是在一个繁殖群体中维持的。我们将研究aav转导细胞分泌治疗水平酶的能力，并确定可以纠正转导部位周围脑组织的体积。我们最近也表明，通过非侵入性核磁共振（NMR）方法可以定量评估活体动物的显著病理。治疗效果将在死前通过临床神经学评估和mr进行评估，这些结果将与死后组织病理学、电子显微镜和生化分析进行比较。α -甘露甘露病猫是评估大型哺乳动物大脑中枢神经系统治疗的模型，具有弥散性病变，在类似于治疗人类疾病时将遇到的条件下。

DESCRIPTION (provided by applicant): The lysosomal storage diseases are a group of inherited enzyme deficiencies that produce fatal degenerative syndromes, most of which affect the CNS. Studies of neural stem cell transplantation and direct gene transfer in mouse disease models have shown that supplying the normal enzyme can significantly reduce pathology. However, metabolic diseases that affect the CNS typically have global lesions and gene delivery within the brain has been relatively limited, particularly in large mammals. We have shown that injection of AAV2 vectors into the parenchyma of the brain in the mouse results in localized transduction, but can mediate widespread distribution of the normal enzyme by secretion. This mediates correction of storage lesions in cells distal from the transduction site, by receptor-mediated endocytosis. We have recently found that when AAV2 is injected into the cerebral lateral ventricles in the newborn mouse brain, the vector becomes widely distributed by the CSF circulation, resulting in disseminated gene expression. In this project we will study an inherited deficiency of acidic alpha-D-mannosidase (MANB), which results in the accumulation of undegraded mannose-rich oligosaccharides in cellular lysosomes, prominently in the central nervous system (CNS), causing mental retardation and other abnormalities. We have studied the genetics, biochemistry, and pathology of a cat model of the human disease, which is maintained in a breeding colony. We will investigate the ability of AAV-transduced cells to secrete therapeutic levels of enzyme and determine the volume of brain tissue that can be corrected surrounding transduction sites. We also have shown recently that there is significant pathology that can be quantitatively evaluated in living animals by non-invasive nuclear magnetic resonance (NMR) methods. The effects of treatment will be evaluated ante-mortem by clinical neurologic assessments and MR. These findings will be compared to post-mortem analysis by histopathology, electron microscopy, and biochemical analyses. The alpha-mannosidosis cat is a model for evaluating treatment of the CNS in a large mammalian brain, with disseminated lesions, under conditions similar to those that will be encountered in treating the human disease.