Involvement of a serine protease in the synthesis of platelet-activating factor by endothelial cells stimulated by tumor necrosis factor-α or interleukin-1α

Federico Bussolino, Marco Arese, Lugi Silvestro, Raffaella Soldi, Emilio Benfenati, Fiorella Sanavio, Massimo Aglietta, Amalia Bosia, Giovanni Camussi

Research output: Contribution to journalArticlepeer-review


It has been shown that production of platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) by endothelial cells (EC) stimulated with tumor necrosis factor (TNF)-α and interleukin (IL)-1α requires the synthesis of new proteins and is regulated by anti-proteinases. Here, we demonstrate that TNF-α and IL-1α induce the expression by EC of a 34-kDa diisopropyl fluorophosphate-binding protein immunoprecipitated by an antihuman elastase antibody. This protein is released in the medium and cleaves the chromogenic substrate N-methoxysuccinyl- Ala-Ala-Pro-Val p-anilide, which is specific for elastase. The generation of this elastase-like protein seems to be important for the synthesis of PAF induced by TNF-α and IL-1α, as suggested by the following observations: (a) it precedes the synthesis of PAF; (b) the inhibitors of serine protease and anti-human elastase antibody prevent the synthesis of PAF and the activation of 1-O-alkyl-2-lyso-glycerophosphocholine acetyl-CoA: acetyltransferase, which is a key enzyme of the PAF remodelling pathway; (c) elastase, at concentrations similar to that detectable in the medium of cytokine-activated EC, elicits a rapid synthesis of PAF by EC. High-performance liquid chromatography-tandem mass spectrometric analysis of bioactive PAF demonstrates that the molecular species produced after stimulation of EC with TNF-α, IL-1α or elastase are similar, with a predominant synthesis of the alkyl species. These results indicate that TNF-α and IL-1α stimulate the production of a serine protease which is critical in the activation of enzymes involved in PAF synthesis, suggesting the potential involvement of this mechanism in the regulation of EC functions.

Original languageEnglish
Pages (from-to)3131-3139
Number of pages9
JournalEuropean Journal of Immunology
Issue number12
Publication statusPublished - Dec 1994


  • Elastase
  • Endothelial cells
  • Interleukin-1
  • Platelet-activating factor
  • Tumor necrosis factor

ASJC Scopus subject areas

  • Immunology


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