Molecular basis for globotriaosylceramide regulation and enzyme uptake in immortalized aortic endothelial cells from Fabry mice

作者：Meng Xing Li; Day Taniqua S; McNeill Nathan; Ashcraft Paula; Frischmuth Thomas; Cheng Seng H; Liu Zhi Ping; Shen Jin Song; Schiffmann Raphael

来源：Journal of Inherited Metabolic Disease, 2016, 39(3): 447-455.

DOI：10.1007/s10545-016-9920-6

Fabry disease is caused by deficient activity of alpha-galactosidase A and subsequent intracellular accumulation of glycosphingolipids, mainly globotriaosylceramide (Gb(3)). Vascular endothelial cells may play important roles in disease pathogenesis, and are one of the main target cell types in therapeutic interventions. In this study, we generated immortalized aortic endothelial cell lines from a mouse model of Fabry disease. These cells retained endothelial cell-specific markers and functions. Gb(3) expression level in one of these clones (referred to as FMEC2) was highly susceptible to culture media, and appeared to be regulated by glucosylceramide synthase. Results also showed that Gb(3) could be upregulated by hydrocortisone. FMEC2 express the mannose 6-phosphate receptor and sortilin but not the mannose receptor. Uptake studies suggested that sortilin plays a role in the binding and internalization of mammalian cell-produced alpha-galactosidase A. Moss-aGal (a plant-made enzyme) was endocytosed by FMEC2 via a receptor other than the aforementioned receptors. In conclusion, this study suggests that glucosylceramide synthase and hydrocortisone may play important roles in modulating Gb(3) levels in Fabry mouse aortic endothelial cells, and that endocytosis of recombinant alpha-galactosidase A involves a combination of multiple receptors depending on the properties of the enzyme.

• 出版日期2016-5