Toll-like receptors expression and NF-κB activation in peritoneal leukocytes in morphine-mediated impairment of zymosan-induced peritonitis in swiss mice.
Zymosan-induced peritonitis represents a well-described model of acute inflammation. The binding of zymosan with its specific Toll-like receptors (TLR2 and TLR6) on leukocytes initiates activation and phosphorylation of nuclear factor (NF)-κB, which leads to accumulation of NF-κB p65 subunits in the nucleus and subsequently up-regulation of the proinflammatory cytokine genes expression. Intraperitoneal co-administration of zymosan and morphine significantly inhibits peritonitis in several strains of mice by decreasing the influx of exudatory cells; however, mechanisms of this action still remain unclear. We aimed to verify the effects of morphine on NF-κB and TLRs expression at messenger RNA and protein levels during the early stages of zymosan-induced peritonitis. Peritonitis was induced by a single injection of zymosan A or zymosan supplemented with morphine in Swiss mice. At selected time points, after stimulation, peritoneal leukocytes were harvested. The TLRs and NF-κB expression was assessed by real-time PCR and flow cytometry. In comparison with the mice injected with zymosan only, morphine co-injection significantly decreased the expression of phospho-NF-κB and TLR2 in all investigated immunocompetent cells as well as up-regulated the levels of nitric oxide (NO) in peritoneal fluid. Moreover, supplementation of zymosan with morphine altered the TLR, NF-κB and some proinflammatory cytokines (keratinocyte-derived chemokine, tumor necrosis factor-α) gene expression during ongoing inflammation. We may postulate that after morphine stimulation peritoneal leukocytes recognize less effectively zymosan antigens because of impaired TLRs expression. The lower TLR expression attenuates TLR-mediated signal transduction, which prevents NF-κB activation. Additionally, during zymosan-induced peritonitis, morphine may modulate the NF-κB expression, at least partially, by an up-regulated release of NO, as suggested by others.
Department of Evolutionary Immunobiology, Institute of Zoology, Jagiellonian University, Cracow, Poland. ewa.wypasek@wp.pl
Ewa
E
Wypasek
Joanna
J
Natorska
Agnieszka Irena
AI
Mazur
Elżbieta
E
Kołaczkowska
D000701:Analgesics, Opioid / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D005434:Flow Cytometry / Q000379:methods; D015603:Keratinocytes / Q000166:cytology; D007962:Leukocytes / Q000378:metabolism*; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology*; D016328:NF-kappa B / Q000096:biosynthesis*; D009566:Nitrates / Q000737:chemistry; D009569:Nitric Oxide / Q000378:metabolism; D009573:Nitrites / Q000737:chemistry; D010537:Peritoneum / Q000166:cytology*; D010538:Peritonitis / Q000276:immunology; D010766:Phosphorylation; D012333:RNA, Messenger / Q000378:metabolism; D013997:Time Factors; D051195:Toll-Like Receptor 2 / Q000096:biosynthesis*; D051216:Toll-Like Receptor 6 / Q000096:biosynthesis*
D000701:Analgesics, Opioid; D016328:NF-kappa B; D009566:Nitrates; D009573:Nitrites; D012333:RNA, Messenger; C493486:Tlr2 protein, mouse; C495369:Tlr6 protein, mouse; D051195:Toll-Like Receptor 2; D051216:Toll-Like Receptor 6; D009569:Nitric Oxide; D009020:Morphine