title: PKA-dependent activation of PKC, p38 MAPK and IKK in macrophage: implication in the induction of inducible nitric oxide synthase and interleukin-6 by dibutyryl cAMP.
abstract: In this study, we examined the signal transduction of dibutyryl cyclic adenosine monophosphate (dBcAMP) to stimulate the release of nitric oxide (NO) and interleukin-6 (IL-6) from J774 macrophages. These actions of dBcAMP were diminished by the presence of the inhibitors of protein kinase A (PKA), protein kinase C (PKC), p38 MAPK and nuclear factor-kappa B (NF-kappaB). In contrast, Go 6976 and PD98059 had no significant effects. Consistently, dBcAMP caused membrane translocation of PKCbetaII, delta, mu, lambda and zeta isoforms, and increased atypical protein kinase C (aPKC) and p38 MAPK activities. The nuclear translocation and DNA-binding study revealed that dBcAMP stimulated NF-kappaB, activator protein-1 (AP-1), and CAAT/enhancer-binding protein (c/EBPbeta). Via PKA, PKC and p38 MAPK-dependent signals, dBcAMP also induced inhibitory subunit of NF-kappaB (IkappaB) degradation, IkappaB kinase (IKK) activation, nuclear translocation of NF-kappaB subunit p65 and its association with the CREB-binding protein (CBP). These results illustrate that PKA activation in macrophages is able to stimulate PKC and p38 MAPK, which lead to IKK-dependent NF-kappaB activation and contribute to the induction of inducible nitric oxide synthase (iNOS) and IL-6 genes.
authors.affiliation: Department of Surgery, Chi-Mei Foundation Hospital, Tainan, Taiwan.
authors.forename: Chung-Ching
authors.initials: CC
authors.lastname: Chio
authors.forename: Ying-Hsin
authors.initials: YH
authors.lastname: Chang
authors.forename: Ya-Wen
authors.initials: YW
authors.lastname: Hsu
authors.forename: Kwan-Hwa
authors.initials: KH
authors.lastname: Chi
authors.forename: Wan-Wan
authors.initials: WW
authors.lastname: Lin
mesh_terms: D000818:Animals; D003994:Bucladesine / Q000494:pharmacology*; D002227:Carbazoles / Q000494:pharmacology; D002352:Carrier Proteins / Q000494:pharmacology; D002460:Cell Line; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D051550:I-kappa B Kinase; D007211:Indoles / Q000494:pharmacology; D015850:Interleukin-6 / Q000096:biosynthesis*; D047908:Intracellular Signaling Peptides and Proteins; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000096:biosynthesis*; D052247:Nitric Oxide Synthase Type II; D010766:Phosphorylation / Q000187:drug effects; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D002227:Carbazoles; D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D005419:Flavonoids; D007211:Indoles; D015850:Interleukin-6; D047908:Intracellular Signaling Peptides and Proteins; D016328:NF-kappa B; C015482:protein kinase modulator; C081021:Go 6976; D003994:Bucladesine; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; D017346:Protein Serine-Threonine Kinases; C496564:Chuk protein, mouse; D051550:I-kappa B Kinase; C496562:Ikbkb protein, mouse; C496566:Ikbke protein, mouse; D011493:Protein Kinase C; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one