Studies of Gaucher Disease: A Prototype Lipidosis

描述(由申请人提供)： 这项拟议的研究侧重于在我们的高谢病小鼠模型中对药物伴侣疗法的体内评估，高谢病是一种常见的、典型的先天性新陈代谢错误。建议的研究解决的假设是：1)原型竞争抑制物，称为药理伴侣，可以提高所选突变酶的活性/功能，并在体内具有治疗作用。这不仅对内脏变异有重要意义，而且对中枢神经系统变异也有重要意义，因为目前的酶(ET)或基因疗法不适用于这些常见的高谢病变异。2)这类分子伴侣可通过改善治疗酶的活性和/或递送来提高ET或基因治疗的效率。酸性葡萄糖苷酶[GCase]活性不足启动了病理过程，组织中底物葡萄糖神经酰胺[GC]通量的正常化对于阻止疾病进展和恢复健康至关重要。这项建议的目的是使用我们独特的带有敲入GCase点替换的小鼠模型作为测试系统，评估选定的药理伴侣对组织特异性、鞘糖脂(GSL)存储和反应的体内影响。GCase中选定的“敲入”突变在催化活性、被破坏的溶酶体运输和/或细胞外稳定性方面显示出可纠正的缺陷。由于体外(培养中的分裂细胞)和体内(主要是未分裂的组织细胞)的机制或作用可能不同，因此将在体外和体内对突变酶的性质的影响之间进行相关性。将努力确定纠正细胞GC新陈代谢所需组织中GCase活性的水平。GCase缺陷突变小鼠的研究将被用来评估选定的伴侣在体内逆转/改善组织学和血脂异常的能力。这些研究的基础是我们的gba点突变小鼠模型的可用性、用于GCase表征的系统、我们的小鼠体内可控的、组织特异性的GCase表达，以及我们的初步数据有力地支持选定的药理伴侣的体内治疗效果。

DESCRIPTION (provided by applicant): The proposed research focuses on the in vivo evaluation of pharmacological chaperone therapies in our mouse models of Gaucher disease, a common and prototype inborn error of metabolism. The proposed studies address the hypotheses that: 1) Prototype competitive inhibitors, termed pharmacologic chaperones, can increase selected mutant enzymes' activity/function and be therapeutic in vivo. This has import for the visceral variants, but also, and importantly, for the CNS variants since current enzyme (ET) or gene therapies are not available for these common variants of Gaucher disease. 2) Such chaperones could be used to enhance the efficiency of ET or gene therapy by improving the therapeutic enzyme's activity and/or delivery. The insufficient activity of acid ¿-glucosidase [GCase] initiates the pathological processes, and normalization of substrate glucosylceramide [GC] flux in tissues is essential to stop disease progression and to restore health. The objectives of this proposal are to evaluate the in vivo effects of selected pharmacologic chaperones on tissue specific, glycosphingolipid (GSL) storage and responses using our unique mouse models with knock-in GCase point substitutions as test systems. Selected "knocked-in" mutations in GCases exhibit correctible deficits in catalytic activity, of disrupted lysosomal trafficking, and/or of stability properties ex vivo in cells. Correlations will be made between the ex vivo and in vivo effects on the properties of the mutant enzymes since the ex vivo (dividing cells in culture) and in vivo (mostly non-dividing tissue cells) mechanisms or effects may differ. Efforts will be directed to defining the levels of GCase activity in tissues needed to correct cellular GC metabolism. GCase deficient mutant mouse studies will be used to evaluate the in vivo capacity of selected chaperones to reverse/improve histological and lipid abnormalities. These studies are grounded in the availability of our gba point mutated mouse models, systems for GCase characterization, our mice with in vivo controllable, tissue specific, expression of GCase, and our preliminary data strongly supporting in vivo therapeutic effects of selected pharmacological chaperones.