Formation of free sphingosine and ceramide from exogenous ganglioside GM1 by cerebellar granule cells in culture

FEBS Letters

Bassi, Rosaria¹  Riboni, Laura¹  Sonnino, Sandro¹  Tettamanti, Guido¹ 

[1] Study Center for the Functional Biochemistry of Brain Lipids, epartment of Medical Chemistry and Biochemistry, The Medical School, University of Milan, Milan, Italy

关键词: Sphingosine;    Ceramide;    Ganglioside;    Cerebellar granule cells;    Second messengers;    Sph;    sphingosine;    NcuAc;    N-acetylneuraminic acid;    BSA;    bovine serum albumin;    HPLTC;    high-performance thin-layer chromatography;   

DOI  :  10.1016/0014-5793(92)80193-K

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Cerebellar granule cells differentiated in culture were incubated with ganglioside [³H-Sph]GM1 in order to have it inserted into the plasma membrane and metabolized. Among the formed metabolites radioactive sphingosine and ceramide were identified. [³H]Ceramide started to be measurable after 10 min of incubation (pulse), and [³H]sphingosine after 15 min. Their concentrations increased with pulse time, and after a 1-hour pulse, with chase time. After a 1-hour pulse with 2 × 10⁻⁶ M [³H-Sph]GM1 followed by a 4-hour chase, the amount of [³H]sphingosine and [³H]ceramide formed were 0.04 and 0.4 pmol/10⁶ cells, respectively. Particularly the ability to produce sphingosine was higher in differentiated than in undifferentiated cells. It is concluded that ganglioside turnover contributes to the maintenance of the intracellular levels of free sphingosine and ceramide.

【 授权许可】

Unknown