Sphingosine-1-phosphate induces a Ca2+ signal in primary rat astrocytes and a Ca2+ signal and shape changes in C6 rat glioma cells

✍ Scribed by Piet W.L. Tas; Klaus Koschel

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 327 KB
• Volume: 52
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/(sici)1097-4547(19980515)52:4<427::aid-jnr6>3.0.co;2-b

✦ Synopsis

Treatment of rat glioma C6 cells with the ␤-adrenergic agonist L-isoproterenol leads to a rise in cAMP level and a subsequent change in cell morphology from an epithelial to an astrocytic type of appearance. This morphological response is reverted by the addition of sphingosine-1-phosphate (S1P) with an EC 50 of 10 nM. In rat glioma C6 cells loaded with the Ca 2؉ indicator Fura-2, S1P evoked Ca 2؉ release from internal stores and Ca 2؉ influx from the external medium. Half-maximal stimulation of the Ca 2؉ increase was 10-20 nM. A similar Ca 2؉ signal was observed in primary rat astrocytes loaded with the Ca 2؉ indicator fluo-3. Pretreatment of the C6 cells with PMA (162 nM) prevented both the S1P-induced Ca 2؉ increase and the morphological reversion. Ca 2؉ ions therefore seem essential for the morphological reversion by S1P. Pretreatment of the cells with the Clostridium botulinum C3 exoenzyme did not affect the reversion of the morphological response by S1P, indicating that the small GTP-binding protein Rho is not involved in the S1P-induced reversion.