[The metabolism of radiolabelled GM1-ganglioside in cultured skin fibroblasts from controls and patients with GM1-gangliosidosis].
The metabolism of [3-3H-sphingosine] GM1-ganglioside was studied in cultured skin fibroblasts from control and patients with beta-galactosidase deficiency, primarily or secondarily. When dissolved in the medium with phosphatidylserine, GM1-ganglioside was efficiently taken up by cultured skin fibroblasts and transferred into lysosomes. A pulse-chase study revealed that [3-3H-sphingosine] GM1-ganglioside was metabolized to GM2-, GM3-ganglioside, ceramide, ceramide monohexoside, ceramide dihexoside and sphingomyelin. In a 20h pulse study, cell lines from patients with GM1-gangliosidosis of infantile, juvenile and adult types hydrolyzed 2 approximately 5%, 20 approximately 44% and 54 approximately 58% of the total endocytosed GM1-ganglioside respectively. These values were lower than in the control cells (62.2 +/- 5.43% (n=10). The hydrolysis rates of exogenous [3-3H-sphingosine] GM1-ganglioside in cultured skin fibroblasts from various types of GM1-gangliosidosis closely correlated to the clinical severity. This method is also useful to the diagnosis of impaired ganglioside metabolism.
Inui
K
K
Department of Pediatrics, Faculty of Medicine, Osaka University.
D002478:Cells, Cultured; D005347:Fibroblasts / Q000378:metabolism; D005677:G(M1) Ganglioside / Q000493:pharmacokinetics; D016537:Gangliosidosis, GM1 / Q000175:diagnosis*; D006801:Humans; D008247:Lysosomes / Q000378:metabolism; D012867:Skin / Q000166:cytology*
D005677:G(M1) Ganglioside