Studies of Gaucher Disease: A Prototype Lipidosis

描述（由申请人提供）： 拟议的研究重点是在我们的高雪氏病，一种常见的和原型的先天性代谢缺陷的小鼠模型中的药物伴侣疗法的体内评价。提出的研究解决了以下假设：1）原型竞争性抑制剂，称为药理学伴侣，可以增加所选突变酶的活性/功能，并且在体内具有治疗性。这不仅对内脏变异有重要意义，而且重要的是，对CNS变异也有重要意义，因为目前的酶（ET）或基因疗法不适用于戈谢病的这些常见变异。2)这种分子伴侣可用于通过改善治疗酶的活性和/或递送来增强ET或基因治疗的效率。酸性葡萄糖苷酶[GCase]活性不足会引发病理过程，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。本提案的目的是使用我们独特的具有敲入GCase点取代的小鼠模型作为测试系统，评价所选药理学分子伴侣对组织特异性鞘糖脂（GSL）储存和反应的体内影响。GCases中选择的“敲入”突变表现出催化活性、破坏的溶酶体运输和/或离体细胞稳定性的可校正缺陷。由于离体（培养物中的分裂细胞）和体内（主要是非分裂组织细胞）机制或效应可能不同，因此将在离体和体内对突变酶性质的影响之间建立相关性。将致力于确定纠正细胞GC代谢所需的组织中GCase活性水平。GCase缺陷突变小鼠研究将用于评价所选分子伴侣逆转/改善组织学和脂质异常的体内能力。这些研究基于我们的gba点突变小鼠模型的可用性，GCase表征系统，我们的具有体内可控的组织特异性GCase表达的小鼠，以及我们的初步数据，这些数据强烈支持所选药理学伴侣的体内治疗作用。

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.