title: Cl-IB-MECA enhances TNF-α release in peritoneal macrophages stimulated with LPS.
abstract: Adenosine receptor A3 (A3R) belongs to the Gi/Gq-coupled receptor family, that leads to the intracellular cAMP reduction and intracellular calcium increase, respectively. A3R is widely expressed and it can play a crucial role in many patho-physiological conditions, including inflammation. Here we investigate the effect of Cl-IB-MECA, A3R agonist, on the production of TNF-α. We found that Cl-IB-MECA enhances LPS-induced TNF-α release in peritoneal macrophages. This effect is reduced by MRS1191, A3R antagonist and by forskolin, activator of adenylyl cyclase. pIκBα increased in LPS+Cl-IB-MECA-treated macrophages, while total IκB kinase-β (IKKβ) reduced. Indeed, p65NF-κB nuclear translocation increased in cells treated with LPS+Cl-IB-MECA. Moreover, IMD 0354, IKKβ inhibitor, significantly abrogated the effect of Cl-IB-MECA on TNF-α release. Inhibition of protein kinase C (PKC) significantly reduced Cl-IB-MECA-induced TNF-α release in LPS-stimulated macrophages. Furthermore, LY-294002, PI3K inhibitor, reduced the TNF-α production enhanced by Cl-IB-MECA, although the phosphorylation status of Akt did not change in cells treated with LPS+Cl-IB-MECA than LPS alone. In summary, these data show that Cl-IB-MECA is able to enhance TNF-α production in LPS-treated macrophages in an NF-κB- dependent manner.
authors.affiliation: Department of Pharmaceutical Sciences, University of Salerno, Fisciano Salerno, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Forte
authors.forename: Rosalinda
authors.initials: R
authors.lastname: Sorrentino
authors.forename: Antonella
authors.initials: A
authors.lastname: Montinaro
authors.forename: Aldo
authors.initials: A
authors.lastname: Pinto
authors.forename: Silvana
authors.initials: S
authors.lastname: Morello
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D008070:Lipopolysaccharides / Q000494:pharmacology*; D017737:Macrophages, Peritoneal / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism; D018047:Receptors, Purinergic P1 / Q000187:drug effects / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
chemical_list: D008070:Lipopolysaccharides; D016328:NF-kappa B; D018047:Receptors, Purinergic P1; D019869:Phosphatidylinositol 3-Kinases; D011493:Protein Kinase C; D000241:Adenosine; C090034:2-chloro-N(6)-(3-iodobenzyl)adenosine-5'-N-methyluronamide