Recombinant human acid alpha-glucosidase corrects acid alpha-glucosidase-deficient human fibroblasts, quail fibroblasts, and quail myoblasts.

Journal Article (Journal Article)

Acid alpha-glucosidase (GAA) deficiency causes Pompe disease, a lethal lysosomal glycogen storage disease for which no effective treatment currently exists. We investigated the endocytic process in deficient cells of human recombinant GAA produced in Chinese hamster ovary cells, and the potential of GAA-deficient Japanese acid maltase-deficient quail as a model for evaluating the enzyme replacement therapy for Pompe disease. After 24-h incubation with a single dose of recombinant enzyme, intracellular GAA and glycogen levels in deficient human fibroblasts were normalized, and this correction lasted for 7 d. The 110-kD precursor recombinant enzyme was processed to the 76-kD mature form within 24 h after uptake. Intracellular GAA levels in deficient quail fibroblasts and myoblasts were similarly corrected to their average normal levels within 24 h. Differences existed in the efficiency of endocytosis among subfractions of the enzyme, and among different cell types. Fractions with a larger proportion of precursor GAA were endocytosed more efficiently. Quail fibroblasts required a higher dose, 4200 nmol.h-1.mL-1 to normalize intracellular GAA levels than human fibroblasts, 1290 nmol.h-1.mL-1, whereas primary quail myoblasts required 2800 nmol.h-1.mL-1. In all three cell lines, the endocytosed enzyme localized to the lysosomes on immunofluorescence staining, and the endocytosis was inhibited by mannose 6-phosphate (Man-6-P) added to the culture medium. Despite structural differences in Man-6-P receptors between birds and mammals, these studies illustrate that Man-6-P receptor mediated endocytosis is present in quail muscle cells, and demonstrate the potential of acid maltase-deficient quail to test receptor mediated enzyme replacement therapy for Pompe disease.

Full Text

Duke Authors

Cited Authors

  • Yang, HW; Kikuchi, T; Hagiwara, Y; Mizutani, M; Chen, YT; Van Hove, JL

Published Date

  • March 1, 1998

Published In

Volume / Issue

  • 43 / 3

Start / End Page

  • 374 - 380

PubMed ID

  • 9505277

International Standard Serial Number (ISSN)

  • 0031-3998

Digital Object Identifier (DOI)

  • 10.1203/00006450-199803000-00011


  • eng

Conference Location

  • United States