Decrease of PECAM-1-gene-expression induced by proinflammatory cytokines IFN-γ and IFN-α is reversed by TGF-β in sinusoidal endothelial cells and hepatic mononuclear phagocytes : Research article / Katrin Neubauer, Alexander Lindhorst, Kyrylo Tron, Giuliano Ramadori, Bernhard Saile
Background and aim: The mechanisms of transmigration of inflammatory cells through the sinusoids are still poorly understood. This study aims to identify in vitro conditions (cytokine treatment) which may allow a better understanding of the changes in PECAM (platelet endothelial cell adhesion molecule)-1-gene-expression observed in vivo. Methods and results: In this study we show by immunohistochemistry, that there is an accumulation of ICAM-1 (intercellular cell adhesion molecule-1) and ED1 positive cells in necrotic areas of livers of CCl4-treated rats, whereas there are few PECAM-1 positive cells observable. After the administration of CCl4, we could detect an early rise of levels of IFN-? followed by an enhanced TGF-? protein level. As shown by Northern blot analysis and surface protein expression analysed by flow cytometry, IFN-?-treatment decreased PECAM-1-gene-expression in isolated SECs (sinusoidal endothelial cells) and mononuclear phagocytes (MNPs) in parallel with an increase in ICAM-1-gene-expression in a dose and time dependent manner. In contrast, TGF-?-treatment increased PECAM-1-expression. Additional administration of IFN-? to CCl4-treated rats and observations in IFN-?-/- mice confirmed the effect of IFN-? on PECAM-1 and ICAM-1-expression observed in vitro and increased the number of ED1-expressing cells 12 h after administration of the toxin.Conclusion: The early decrease of PECAM-1-expression and the parallel increase of ICAM-1-expression following CCl4-treatment is induced by elevated levels of IFN-? in livers and may facilitate adhesion and transmigration of inflammatory cells. The up-regulation of PECAM-1-expression in SECs and MNPs after TGF-?-treatment suggests the involvement of PECAM-1 during the recovery after liver damage.
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|Part of:||BMC physiology 8(2008), 9, Seite 1-14|
|Physical description:||Online-Ressource (PDF-Datei: 14 S., 768,19 KB)|
|Basic Classification:||44.88 Urologie, Nephrologie|