Studies on ether-phospholipids of vascular smooth muscle cells. Identification of a rapid Ca2+-dependent hydrolysis of alkyl-phosphatidylethanolamine promoted by endothelin-1

Autor: Hugues Chap, Clotilde Cariven, Valérie Georgeaud, Marie-Claude Prévost, Eric Maury, Cécile Comminges
Rok vydání: 1997
Předmět:
Zdroj: Biochimica et Biophysica Acta (BBA) - Molecular Cell Research. 1355(1):69-80
ISSN: 0167-4889
DOI: 10.1016/s0167-4889(96)00112-7
Popis: We have investigated the metabolism of 1-O-[3H]octadecyl-sn-glycero-3-phosphocholine ([3H]lyso PAF) and [3H]myristic acid in secondary cultures of aortic smooth muscle cells (SMC) to characterize the origin of second messengers generated upon stimulation with endothelin-1 (ET-1). When cells were labelled with [3H]lyso PAF, we observed a transfer of the label from phosphatidylcholine (PC) to phosphatidylethanolamine (PE). In contrast, incubation with [3H]myristate labelled mainly PC. Both precursors were incorporated into all PC and PE subclasses. However, [3H]lyso PAF labelled mainly alkyl-subclasses while [3H]myristate was associated with diacyl-subclasses. Using these specific labelling procedures, we have shown that ET-1 induced a strong hydrolysis of PE. This hydrolysis was specific for alkyl-PE with a maximum after 5 s of stimulation. We have also observed an extracellular Ca2+-dependent increase in diglyceride (DG), phosphatidic acid (PA) and mainly triglyceride (TG) concomitant to alkyl-PE hydrolysis. Thus, alkyl-DG generated from alkyl-PE appears to be a major product in ET-1 stimulation of SMC. These results suggest a new level of complexity in the signal transduction cascade involving a specificity for phospholipid subclasses.
Databáze: OpenAIRE
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