title: TNFR1-induced NF-kappaB, but not ERK, p38MAPK or JNK activation, mediates TNF-induced ICAM-1 and VCAM-1 expression on endothelial cells.
abstract: Tumour necrosis factor (TNF) is a pro-inflammatory cytokine, whose primary targets include vascular endothelial cells. TNF-mediated adhesion molecule expression has been shown to play a central role in endothelial cells inflammatory responses and disorders such as atherosclerosis. However it is not fully understand how the TNF receptor subtypes, namely TNFR1 and TNFR2, regulate inflammatory responses in endothelial cells. The aim of this study was to elucidate the kinase signalling pathways that TNF receptors activate, and determine the pathways responsible for downstream expression of adhesion molecules, intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in human endothelial cells. Using human umbilical vein endothelial cells (HUVEC), we demonstrated that TNF activates a range of mitogen-activated protein kinases (MAPKs), including the extracellular-regulated kinase (ERK) pathway and the p38MAPK and c-Jun N-terminal kinase (JNK) stress kinase pathways. Human endothelial cells express both TNF receptor subtypes at low levels, however using TNFR-specific agonistic agents, we uncovered that TNF acts through its TNFR1 receptor subtype to activate NF-kappaB transcriptional pathways. Further investigation revealed that ICAM-1 and VCAM-1 mRNA and protein are induced by TNFR1 (but not TNFR2) in a wholly NF-kappaB-dependent manner. These findings reveal for the first time that TNF stimulation of adhesion molecules ICAM-1 and VCAM-1 in human endothelial cells occurs through the TNFR1 subtype and is mediated by the NF-kappaB pathway, but not the ERK, p38MAPK or JNK kinase pathways.
authors.affiliation: School of Chemical Sciences and Pharmacy, University of East Anglia, Norwich, NR4 7TJ, United Kingdom.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhou
authors.forename: Michelle C
authors.initials: MC
authors.lastname: Connell
authors.forename: David J
authors.initials: DJ
authors.lastname: MacEwan
mesh_terms: D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism*; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000494:pharmacology*; D048069:Tumor Necrosis Factors / Q000494:pharmacology*; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D004791:Enzyme Inhibitors; D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D012333:RNA, Messenger; D047888:Receptors, Tumor Necrosis Factor, Type I; D048069:Tumor Necrosis Factors; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; D000072000:NF-KappaB Inhibitor alpha; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases