Hyperosmotic stimuli inhibit VCAM-1 expression in cultured endothelial cells via effects on interferon regulatory factor-1 expression and activity.
Transcriptional up-regulation of the VCAM-1 gene, induced by proinflammatory cytokines such as IL-1beta and TNF-alpha, requires activation of not only NF-kappaB, but also involves interferon regulatory factor (IRF)-1. During a study of gene induction by mechanical stimuli in cultured human endothelial cells, we noted that medium hyperosmolarity appeared to influence cytokine-induced expression of VCAM-1. Indeed, addition of hyperosmotic, pathophysiologically relevant concentrations of NaCl effectively inhibited IL-1beta or TNF-alpha induction of VCAM-1, but not E-selectin, at the level of mRNA and cell surface protein. Because induction of both VCAM-1 and E-selectin by these cytokines is NF-kappaB dependent, we investigated whether the inhibitory effect of hyperosmotic medium might involve IRF-1. Electrophoretic mobility shift assays of the VCAM-1 promoter demonstrated that hyperosmotic medium suppressed IL-1beta- or TNF-alpha-activated binding activities of IRF-1, but not NF-kappaB, to their respective sites. Hyperosmotic medium also inhibited the expression of IRF-1 induced by TNF-alpha or IFN-gamma. Furthermore, hyperosmotic medium inhibited TNF-alpha or IFN-gamma induction of guanylate binding protein-1, another IRF-1-dependent gene. Taken together, hyperosmolarity selectively inhibits cytokine-induced VCAM-1 in endothelial cells, via an IRF-1-dependent mechanism. Thus, pathophysiological fluctuations in plasma osmolarity may influence certain endothelial-dependent components of the inflammatory response and host defense mechanisms.
Vascular Research Division, Department of Pathology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
Hiroshi
H
Ochi
Junichi
J
Masuda
Michael A
MA
Gimbrone
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D003470:Culture Media; D003513:Cycloheximide / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D019040:E-Selectin / Q000235:genetics; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000235:genetics; D005786:Gene Expression Regulation; D007093:Imidazoles / Q000494:pharmacology; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics; D050856:Interferon Regulatory Factor-1; D050832:Interferon-Stimulated Gene Factor 3; D007371:Interferon-gamma / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D018793:Interleukin-13 / Q000494:pharmacology; D015847:Interleukin-4 / Q000494:pharmacology; D016328:NF-kappa B / Q000378:metabolism; D019319:Okadaic Acid / Q000494:pharmacology; D009995:Osmosis; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger; D019311:Staurosporine / Q000494:pharmacology; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D015533:Transcriptional Activation; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics*
D003470:Culture Media; D004268:DNA-Binding Proteins; D019040:E-Selectin; C490287:GBP1 protein, human; D007093:Imidazoles; D050856:Interferon Regulatory Factor-1; D050832:Interferon-Stimulated Gene Factor 3; D007375:Interleukin-1; D018793:Interleukin-13; D016328:NF-kappa B; D010750:Phosphoproteins; D011725:Pyridines; D012333:RNA, Messenger; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D019010:Vascular Cell Adhesion Molecule-1; C079868:gamma interferon activation factor; D018799:Intercellular Adhesion Molecule-1; D019319:Okadaic Acid; D015847:Interleukin-4; D007371:Interferon-gamma; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D003513:Cycloheximide; D019204:GTP-Binding Proteins; D019311:Staurosporine; C093642:SB 203580