Inhibition of p38 and ERK MAP kinases blocks endotoxin-induced nitric oxide production and differentially modulates cytokine expression.
Mitogen-activated protein kinases (MAPKs) are thought to have a critical role in lipopolysaccharide (LPS)-induced immune responses but the molecular mechanisms underlying the mediation of these signaling are not clear. The roles of p38 and extracellular signal-regulated kinase (ERK) in the regulation of nitric oxide (NO) and proinflammatory cytokine expression in J774A.1 macrophages in response to LPS were examined. Specific inhibitors for p38 and ERK, SB203580 and PD98059, respectively, were used. LPS (30ng/ml) activated inducible nitric oxide synthase (iNOS), subsequent NO production, and gene expression for tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, IL-6, and IL-12. Treatment of cultures with SB203580 increased LPS-induced reactive oxygen species (ROS) production, whereas both SB203580 and PD98059 decreased LPS-induced NO production. Concomitant decreases in the expression of iNOS mRNA and protein were detected. SB203580 and PD98059 decreased LPS-induced gene expression of IL-1beta and IL-6. SB203580 increased LPS-induced expression of TNF-alpha and IL-12; PD98059 had no effect on these cytokines. Results indicated that both p38 and ERK pathways are involved in LPS-stimulated NO synthesis and the expression of IL-1beta and IL-6. p38 signaling pathway is involved in LPS-induced ROS, TNF-alpha and IL-12 production.
Department of Physiology and Pharmacology, College of Veterinary Medicine, The University of Georgia, Athens, GA 30602-7389, USA.
Sang Hyun
SH
Kim
Jiyoung
J
Kim
Raghubir P
RP
Sharma
D000818:Animals; D002460:Cell Line; D016207:Cytokines / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004731:Endotoxins / Q000009:adverse effects / Q000037:antagonists & inhibitors*; D005419:Flavonoids / Q000494:pharmacology; D015870:Gene Expression; D007093:Imidazoles / Q000494:pharmacology; D007378:Interleukins / Q000737:chemistry / Q000235:genetics; D008070:Lipopolysaccharides / Q000009:adverse effects / Q000037:antagonists & inhibitors; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D009569:Nitric Oxide / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D011725:Pyridines / Q000494:pharmacology; D012333:RNA, Messenger; D017382:Reactive Oxygen Species / Q000378:metabolism; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000737:chemistry / Q000235:genetics; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism
D016207:Cytokines; D004731:Endotoxins; D005419:Flavonoids; D007093:Imidazoles; D007378:Interleukins; D008070:Lipopolysaccharides; D011725:Pyridines; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one