The pharmacological chaperone 1-deoxygalactonojirimycin increases α-galactosidase A levels in Fabry patient cell lines
The pharmacological chaperone 1-deoxygalactonojirimycin increases α-galactosidase A levels in Fabry patient cell lines
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DOI：
10.1007/s10545-009-1077-0
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发表时间：
2009-06-01
影响因子：
4.2
通讯作者：
Valenzano, K. J.
中科院分区：
文献类型：
--
作者：
Benjamin, E. R.;Flanagan, J. J.;Valenzano, K. J.
法布里病是由编码α-半乳糖苷酶A（α-Gal A）的基因突变引起的X-连锁溶酶体贮积症，其主要鞘糖脂底物神经酰胺三己糖苷（GL-3）随之蓄积。已经报道了超过500种Fabry突变;大约60%是错义的。亚胺糖1-脱氧半乳糖野尻霉素（DGJ，盐酸米加司他，AT 1001）是一种药理学伴侣，可选择性结合α-Gal A，增加物理稳定性、溶酶体运输和细胞活性。为了鉴定a-Gal A的DGJ响应性突变体形式，在来自患有法布里病的男性的培养的淋巴母细胞中评估DGJ孵育对a-Gal A水平的影响，所述法布里病代表75种不同的错义突变、一种插入和一种剪接位点突变。基线α-Gal A水平范围为正常值的0至52%。对于具有不同EC（50）值（820 nmol/L至> 1 mmol/L）的49种不同错义突变体形式，观察到连续DGJ孵育5天后α-Gal A水平增加（1.5至28倍）。响应形式的氨基酸取代位于整个酶的两个结构域。与经典（早发性）法布里病相关的错义突变形式中有一半和与迟发性法布里病相关的大多数（90%）是有反应的。在培养的成纤维细胞与法布里病的男性，DGJ的反应是与相同突变的淋巴母细胞。重要的是，DGJ孵育后，应答性法布里成纤维细胞中升高的GL-3水平降低，表明增加的突变体α-Gal A水平可以减少累积的底物。这些数据表明，DGJ值得进一步评估作为治疗患有各种错义突变的法布里病患者。
Fabry disease is an X-linked lysosomal storage disorder caused by mutations in the gene encoding alpha-galactosidase A (alpha-Gal A), with consequent accumulation of its major glycosphingolipid substrate, globotriaosylceramide (GL-3). Over 500 Fabry mutations have been reported; approximately 60% are missense. The iminosugar 1-deoxygalactonojirimycin (DGJ, migalastat hydrochloride, AT1001) is a pharmacological chaperone that selectively binds alpha-Gal A, increasing physical stability, lysosomal trafficking, and cellular activity. To identify DGJ-responsive mutant forms of alpha-Gal A, the effect of DGJ incubation on alpha-Gal A levels was assessed in cultured lymphoblasts from males with Fabry disease representing 75 different missense mutations, one insertion, and one splice-site mutation. Baseline alpha-Gal A levels ranged from 0 to 52% of normal. Increases in alpha-Gal A levels (1.5- to 28-fold) after continuous DGJ incubation for 5 days were seen for 49 different missense mutant forms with varying EC(50) values (820 nmol/L to > 1 mmol/L). Amino acid substitutions in responsive forms were located throughout both structural domains of the enzyme. Half of the missense mutant forms associated with classic (early-onset) Fabry disease and a majority (90%) associated with later-onset Fabry disease were responsive. In cultured fibroblasts from males with Fabry disease, the responses to DGJ were comparable to those of lymphoblasts with the same mutation. Importantly, elevated GL-3 levels in responsive Fabry fibroblasts were reduced after DGJ incubation, indicating that increased mutant alpha-Gal A levels can reduce accumulated substrate. These data indicate that DGJ merits further evaluation as a treatment for patients with Fabry disease with various missense mutations.