Gene transfer & NMR studies in alpha-mannosidosis brain

描述（由申请方提供）：溶酶体贮积病是一组遗传性酶缺乏症，可产生致死性退行性综合征，其中大部分影响CNS。在小鼠疾病模型中进行神经干细胞移植和直接基因转移的研究表明，提供正常的酶可以显着减少病理。然而，影响CNS的代谢疾病通常具有全局性病变，并且脑内的基因递送相对有限，特别是在大型哺乳动物中。我们已经表明，将AAV 2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。这通过受体介导的内吞作用来介导对转导位点远端细胞中的贮存损伤的校正。我们最近发现，当将AAV 2注射到新生小鼠脑的侧脑室中时，载体通过CSF循环广泛分布，导致播散性基因表达。在这个项目中，我们将研究酸性α-D-甘露糖苷酶（MANB）的遗传性缺乏，这导致未降解的富含甘露糖的寡糖在细胞溶酶体中积累，特别是在中枢神经系统（CNS）中，引起智力低下和其他异常。我们已经研究了人类疾病的猫模型的遗传学，生物化学和病理学，该模型被保持在繁殖群体中。我们将研究AAV转导的细胞分泌治疗水平的酶的能力，并确定可以在转导位点周围校正的脑组织的体积。我们最近还表明，有显着的病理，可以定量评估活动物的非侵入性核磁共振（NMR）方法。将通过临床神经学评估和MR在死前评价给药效果。将这些结果与通过组织病理学、电子显微镜检查和生化分析进行的死后分析进行比较。α-甘露糖苷沉积症猫是用于在与治疗人类疾病中遇到的那些条件相似的条件下，评估具有播散性病变的大型哺乳动物脑中CNS治疗的模型。

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.