title: Tumor necrosis factor-alpha-induced release of plasminogen activator inhibitor-1 from human umbilical vein endothelial cells: involvement of intracellular ceramide signaling event.
abstract: We have investigated the biochemical mechanism of tumor necrosis factor (TNF)-alpha-induced release of plasminogen activator inhibitor-1 (PAI-1) from human umbilical vein endothelial cells (HUVEC). Treatment of HUVEC with TNF-alpha for 3 h resulted in a 2. 8-fold increase in the PAI-1 release compared with control. The increase in PAI-1 release was accompanied by a 133% increase in the intracellular acidic sphingomyelinase (SMase) activity. High-performance liquid chromatographic (HPLC) analysis revealed that the intracellular ceramide levels increased to 126% of the control (P<0.05), but the contents of membranous ceramide remained unaltered. We have previously shown that a cell-permeable ceramide analog, N-acetylsphingosine (C2-ceramide) enhances the PAI-1 release from HUVEC. Here, N-acetylsphinganine (C2-dihydroceramide) was found to specifically suppress both C2-ceramide- and TNF-alpha-induced increase in PAI-1 release from HUVEC without affecting the control PAI-1 release. Treatment of HUVEC with staphylococcal SMase that may mimic the activation of the membranous neutral SMase also increased the PAI-1 release. The increase in PAI-1 release by this mechanism was suppressed by a cyclooxygenase inhibitor, aspirin, whereas the inhibitor did not affect TNF-alpha-induced increase in PAI-1 release. Taken together, these findings suggest that TNF-alpha prominently utilizes the lysosomal acidic SMase-ceramide signaling pathway in the induction of PAI-1 release from HUVEC.
authors.affiliation: Department of Biochemistry, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Fukuoka 814-0180, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Soeda
authors.forename: T
authors.initials: T
authors.lastname: Tsunoda
authors.forename: Y
authors.initials: Y
authors.lastname: Kurokawa
authors.forename: H
authors.initials: H
authors.lastname: Shimeno
mesh_terms: D002518:Ceramides / Q000378:metabolism* / Q000494:pharmacology; D053938:DNA Fragmentation; D011992:Endosomes / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D008247:Lysosomes / Q000378:metabolism; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism*; D015398:Signal Transduction; D013108:Sphingomyelin Phosphodiesterase / Q000378:metabolism; D013110:Sphingosine / Q000031:analogs & derivatives / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D002518:Ceramides; C064769:N-acetylsphingosine; D017395:Plasminogen Activator Inhibitor 1; D014409:Tumor Necrosis Factor-alpha; C109343:dihydroceramide; D013108:Sphingomyelin Phosphodiesterase; D013110:Sphingosine