Lysosomal hydrolases in blood-derived macrophages of patients with I-cell disease.
Three lysosomal hydrolases, beta-galactosidase, beta-glucuronidase, and beta-N-acetylglucosaminidase, were examined in blood-derived macrophages and media of two patients with I-cell disease. The activities of the three enzymes were lower in I-cell macrophages than in normal controls. However, the media collected from these cells possessed higher activities than control media. beta-N-acetylglucosaminidase derived from media of I-cell macrophages was not endocytosed by fibroblasts from patients with Sandhoff's disease and was only partially endocytosed by I-cell macrophages. These findings indicate that blood-derived macrophages of patients with I-cell disease are affected. In addition, the data presented suggest the presence of two types of receptors in human blood-derived macrophages: mannose and mannose-6-phosphate.
D000118:Acetylglucosaminidase / Q000378:metabolism; D005347:Fibroblasts / Q000201:enzymology; D005966:Glucuronidase / Q000378:metabolism; D006801:Humans; D006867:Hydrolases / Q000097:blood*; D007223:Infant; D008247:Lysosomes / Q000201:enzymology*; D008264:Macrophages / Q000201:enzymology*; D008297:Male; D009081:Mucolipidoses / Q000201:enzymology*; D001616:beta-Galactosidase / Q000378:metabolism
D006867:Hydrolases; D001616:beta-Galactosidase; D005966:Glucuronidase; D000118:Acetylglucosaminidase