THE PHARMACOLOGIC TREATMENT OF FABRY DISEASE

α-半乳糖苷酶A缺乏症(Fabry病)是一种遗传性X连锁疾病，导致溶酶体水解酶--α-半乳糖苷酶A活性低下。这种疾病的表型表现为含有α-半乳糖基连接的神经鞘糖脂的积累。这些神经鞘糖脂包括氨基二糖神经酰胺和球三糖神经酰胺，这两种糖脂是志贺氏毒素的受体。除了氨基二糖神经酰胺外，累积的糖脂含有葡萄糖神经酰胺作为其基础脑苷脂。Globotriosylceramide是积聚在患者组织中的主要脂质。Fabry病的主要临床表现包括肾功能衰竭、脑血管疾病、心肌梗死、周围神经系统受累引起的剧烈疼痛和称为血管角化瘤的皮肤病变。我们提出作为这些研究的主要假设，即对葡萄糖神经酰胺合成酶的选择性药理抑制将预防Fabry病的并发症。为了检验这一假设，我们提出了以下具体目标。1.通过对母体化合物的芳香族官能团和叔胺的多样化，构建D-苏氨酸-PDMP同系物的组合库。筛选该文库对葡萄糖神经酰胺合成酶的抑制作用。2.比较新型葡萄糖神经酰胺合成酶抑制剂对葡萄糖神经酰胺合成酶、半乳糖神经酰胺合成酶和神经酰胺转酰基酶的抑制活性，以确定其治疗指数。3.评价候选葡糖神经酰胺合成酶抑制剂在逆转α-半乳糖苷酶基因敲除小鼠和Fabry病患者永生化细胞表型中的作用。4.在α-半乳糖苷酶缺陷基因敲除小鼠中测试预防Fabry表型的候选抑制剂。

Alpha-Galactosidase A deficiency (Fabry Disease) is an inherited X-linked disorder resulting in deficient activity of the lysosomal hydrolase, alpha-galactosidase A. In hemizygous males the phenotypic expression of this disorder is manifest by the accumulation of glycosphingolipids containing alpha-galactosyl linkages. These glycosphingolipids include galabiosylceramide and globotriosylceramide, glycolipids which serve as the receptor for shigatoxin. With the exception of galabiosylceramide, the accumulated glycolipids contain glucosylceramide as their base cerebroside. Globotriosylceramide is the primary lipid which accumulates in the tissues of affected patients. The major clinical manifestations of Fabry disease include renal failure, cerebral vascular disease, myocardial infarction, intense pain due to peripheral nervous system involvement, and skin lesions termed angiokeratomas. We propose as the primary hypothesis for these studies that the selective pharmacological inhibition of glucosylceramide synthase will prevent the complications of Fabry disease. The following specific aims are proposed to test this hypothesis. 1. To generate a combinatorial library of D-threo-PDMP congeners by diversifying the aromatic function and tertiary amine of the parent compound. To screen this library for inhibition of glucosylceramide synthase. 2. To test novel glucosylceramide synthase inhibitors for their therapeutic index by comparing the inhibitory activity against glucosylceramide synthase, galactosylceramide synthase, and ceramide transacylase. 3. To evaluate the role of candidate glucosylceramide synthase inhibitors in reversing the phenotype of primary and immortalized cells from alpha-galactosidase knockout mice and from immortalized cells from patients with Fabry disease. 4. To test candidate inhibitors in alpha-galactosidase deficient knockout mice for prevention of the Fabry phenotype.