Ida H, Kusano K, Suzuki H, Tokoro T, Eto Y
Department of Pediatrics, Tokyo Jikei University School of Medicine, Japan.
Biochem Biophys Res Commun. 1990 Jan 30;166(2):1053-60. doi: 10.1016/0006-291x(90)90917-c.
Cell level studies of 3H-galactosylceramide(GalCer) and 3H-galactosyl sphingosine (GalSph) have been carried out in cultured skin fibroblasts from human and murine globoid cell leukodystrophy (GLD). GalCer loading studies disclosed that the hydrolysis rates of GalCer in human control and GLD were 72% and 45%, respectively, and those from the murine control and GLD cells were 77% and 21%, respectively, on the 5th day of culture. On the other hand, GalSph loading studies showed that the hydrolysis rate of GalSph in the human control and GLD were 40% and 10%, respectively, and those from murine control and GLD cells were 38% and 10% on the 12th day of culture. These data suggest that both GalCer and GalSph degradations were impaired in cell level in human and murine GLD. Furthermore, when radioactive 3H-GalSph was loaded into cultured fibroblasts from murine and human GLD, 3H-GalCer band was formed via GalSph. These data strongly suggest that GalCer could be synthesized through the GalSph route as a minor pathway at least in cultured skin fibroblasts, although the major pathway to synthesize GalCer should be via ceramide.
已对来自人类和鼠类球状细胞脑白质营养不良（GLD）的培养皮肤成纤维细胞进行了3H-半乳糖神经酰胺（GalCer）和3H-半乳糖神经鞘氨醇（GalSph）的细胞水平研究。GalCer加载研究表明，在培养的第5天，人类对照和GLD细胞中GalCer的水解率分别为72%和45%，鼠类对照和GLD细胞中的水解率分别为77%和21%。另一方面，GalSph加载研究显示，在培养的第12天，人类对照和GLD细胞中GalSph的水解率分别为40%和10%，鼠类对照和GLD细胞中的水解率分别为38%和10%。这些数据表明，在人类和鼠类GLD的细胞水平上，GalCer和GalSph的降解均受损。此外，当将放射性3H-GalSph加载到来自鼠类和人类GLD的培养成纤维细胞中时，会通过GalSph形成3H-GalCer条带。这些数据强烈表明，至少在培养的皮肤成纤维细胞中，GalCer可以通过GalSph途径作为次要途径合成，尽管合成GalCer的主要途径应该是通过神经酰胺。
