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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
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 molecu...
Autores principales: | , , , , |
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Formato: | Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2008
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2396664/ https://www.ncbi.nlm.nih.gov/pubmed/18466611 http://dx.doi.org/10.1186/1472-6793-8-9 |
Sumario: | 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 CCl(4)-treated rats, whereas there are few PECAM-1 positive cells observable. After the administration of CCl(4), we could detect an early rise of levels of IFN-γ followed by an enhanced TGF-β protein level. As shown by Northern blot analysis and surface protein expression analysed by flow cytometry, IFN-γ-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-β-treatment increased PECAM-1-expression. Additional administration of IFN-γ to CCl(4)-treated rats and observations in IFN-γ(-/- )mice confirmed the effect of IFN-γ 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 CCl(4)-treatment is induced by elevated levels of IFN-γ in livers and may facilitate adhesion and transmigration of inflammatory cells. The up-regulation of PECAM-1-expression in SECs and MNPs after TGF-β-treatment suggests the involvement of PECAM-1 during the recovery after liver damage. |
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