Qadri Syed M, Bauer Julia, Zelenak Christine, Mahmud Hasan, Kucherenko Yuliya, Lee Seung Hun, Ferlinz Klaus, Lang Florian
Department of Physiology, University of Tübingen, Tübingen, Germany.
Cell Physiol Biochem. 2011;28(2):339-46. doi: 10.1159/000331750. Epub 2011 Aug 16.
Sphingosine kinase 1 phosphorylates sphingosine, which is converted to ceramide by ceramide synthetase. Ceramide triggers eryptosis, the suicidal erythrocyte death characterized by cell shrinkage and phosphatidylserine (PS) exposure at the erythrocyte surface. Erythrocytes lack sphingosine phosphate-degrading enzymes and thus store large quantities of sphingosine phosphate. The present study explored the influence of sphingosine and sphingosine phosphate on eryptosis. Ca(2+), was estimated from Fluo3 fluorescence, cell volume from forward scatter and PS exposure from annexin V-binding in FACS analysis. Sphingosine (0.1 - 10 μM) but not sphingosine-1- phosphate (0.1 - 10 μM) increased Ca(2+), decreased cell volume and increased PS-exposure. The observations disclose sphingosine, but not sphingosine-1-phosphate, as a strong inducer of eryptosis.
