Activation of endothelial cell phospholipase D by sphingosine and sphingosine-1-phosphate.

V. Natarajan, H. N. Jayaram, W. M. Scribner, J. G. Garcia

Research output: Contribution to journalArticlepeer-review

68 Scopus citations


We have investigated the activation of phospholipase D (PLD) by sphingosine and its derivatives in bovine pulmonary artery endothelial cells (BPAEC) prelabeled with [32P]orthophosphate or [32P]lyso phospholipids. Sphingosine, in a dose- and time-dependent manner, stimulated the hydrolysis of [32P]phosphatidylcholine (PC) resulting in the production of [32P]phosphatidic acid (PA), suggesting PLD activation. In the presence of ethanol (150 mM), the accumulation of [32P]phosphatidylethanol was also observed. The sphingosine-induced stimulation of PLD activity was not affected by treatment with the protein kinase C (PKC) inhibitor staurosporine or by down-regulation of PKC with TPA and was independent of extracellular Ca2+, suggesting that the PLD activation was independent of PKC and Ca2+. Chelation of intracellular Ca2+ with BAPTA actually potentiated the sphingosine-stimulated [32P]PC hydrolysis. Furthermore, the activation of PLD by sphingosine was not abolished by treatment of BPAEC with either cholera or pertussis toxin, indicating noninvolvement of toxin-sensitive G-proteins. In addition to hydrolysis of [32P]PC, sphingosine also stimulated PLD-mediated hydrolysis of [32P]phosphatidylethanolamine and [32P]phosphatidylinositol. Among the various sphingoid compounds, in addition to sphingosine, only sphingosine-1-phosphate (Sph-1-P) activated the endothelial cell PLD. The effect of sphingosine and Sph-1-P on PA phosphatase (PA Pase) activity was tested using [3H]glycerol-labeled PA. The Mg(2+)-independent and membrane-associated PA Pase activity was inhibited by sphingosine (IC50 = 200 microM) but not by Sph-1-P. This implies that sphingosine and Sph-1-P share a similar PLD-stimulating property but differ in their PA Pase inhibitory activity.

Original languageEnglish (US)
Pages (from-to)221-229
Number of pages9
JournalAmerican journal of respiratory cell and molecular biology
Issue number2
StatePublished - Aug 1994

ASJC Scopus subject areas

  • Molecular Biology
  • Pulmonary and Respiratory Medicine
  • Clinical Biochemistry
  • Cell Biology


Dive into the research topics of 'Activation of endothelial cell phospholipase D by sphingosine and sphingosine-1-phosphate.'. Together they form a unique fingerprint.

Cite this