title: Effects of genetic and pharmacological inhibition of TNF-alpha in the regulation of inflammation in macrophages.
abstract: Tumour necrosis factor-alpha (TNF-alpha) is an inflammatory cytokine produced by circulating monocytes and resident macrophages during acute inflammation and is responsible for a diverse range of signalling events within cells, leading to necrosis or apoptosis. The biologic activities of TNF are mediated by two receptors TNFR1 and TNFR2, although a lot of studies demonstrated that most of the biological activities of TNF-alpha are mediated through TNFR1. In the present study, we want to evaluate the role of TNF-alpha on regulation of in vitro models of inflammation. In particular we used peritoneal macrophages, from TNF-alphaR1 knock out and TNF-alphaR1 wild-type mice, stimulated with LPS 10 microg/ml and IFN-gamma 100 U/ml. Our results showed that the deletion of TNF-alphaR1 gene significantly reduced the degree of (i) MAPK activation, (ii) IkappaB-alpha degradation, (iii) phosphorylation of Ser536 on the NF-kappaB subunit p65 and (iv) iNOS and COX-2 expression. In addition, to confirm the pivotal role of TNF-alpha on regulation of peritoneal macrophages inflammation, we have also investigated the protective effects of infliximab, a TNF-alpha chimeric mouse/human IgG1 antibody against TNF-alpha. As shown in the present study, the cell incubation with infliximab (0.1 microg/ml, 1 microg/ml and 10 microg/ml) significantly leads to a concentration-dependent inhibition of the inflammatory mediators above described. In conclusion, our study demonstrates that pharmacological and genetic inhibition of the TNF/TNFR1 binding reduce the degree of macrophages inflammation caused by LPS/IFN-gamma stimulation.
authors.affiliation: Dipartment Clinical and Experimental Medicine and Pharmacology, School of Medicine, University of Messina Torre Biologica, Policlinico Universitario, 98123 Messina, Italy.
authors.forename: Concetta
authors.initials: C
authors.lastname: Crisafulli
authors.forename: Maria
authors.initials: M
authors.lastname: Galuppo
authors.forename: Salvatore
authors.initials: S
authors.lastname: Cuzzocrea
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D015870:Gene Expression / Q000187:drug effects; D000069285:Infliximab; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D051379:Mice; D018345:Mice, Knockout; D016328:NF-kappa B / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D010537:Peritoneum / Q000166:cytology; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000235:genetics* / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*
chemical_list: D000893:Anti-Inflammatory Agents; D000911:Antibodies, Monoclonal; D016328:NF-kappa B; D047888:Receptors, Tumor Necrosis Factor, Type I; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2