title: PKC- and ERK-dependent activation of I kappa B kinase by lipopolysaccharide in macrophages: enhancement by P2Y receptor-mediated CaMK activation.
abstract: 1. Although accumulating studies have identified I kappa B kinase (IKK) to be essential for controlling NF-kappa B activity in response to several cytokines, the upstream kinases that control IKK activity are still not completely known. We have previously reported that G protein-coupled P2Y(6) receptor activation by UTP potentiates lipopolysaccharide (LPS)-induced I kappa B phosphorylation and degradation, and NF-kappa B activation in J774 macrophages. In this study, we investigated the upstream kinases for IKK activation by UTP and LPS. 2. In murine J774 macrophages, LPS-induced NF-kappa B activation was inhibited by the presence of PDTC, D609, Ro 31-8220, PD 098059 and SB 203580. 3. Accompanying NF-kappa B activation, LPS induced I kappa B degradation and IKK activation were reduced by PDTC, D609, Ro 31-8220 and PD 098059, but not by SB 203580. 4. Although UTP itself slightly induced IKK activation, this response was synergistic with LPS. BAPTA/AM and KN-93 (a calcium/calmodulin-dependent protein kinase (CaMK) inhibitor) attenuated UTP- but not LPS-stimulated IKK activity. Synergistic IKK activation between LPS and thapsigargin was further demonstrated in peritoneal macrophages. 5. LPS and UTP co-stimulation additively increased p65 NF-kappa B phosphorylation. In vitro kinase assays revealed that LPS and UTP induced extracellular signal-regulated protein kinase (ERK) and p38 mitogen-activated protein kinase activation were respectively inhibited by PD098059 and SB 203580. 6. Taken together, we demonstration that Gq protein-coupled P2Y(6) receptor activation can potentiate LPS-stimulated IKK activity. While PKC and ERK participate in IKK activation by LPS and UTP, the phosphatidylinositide-phospholipase C-dependent activation of CaMK plays a major role in UTP potentiation of the LPS response.
authors.affiliation: Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: B C
authors.initials: BC
authors.lastname: Chen
authors.forename: W W
authors.initials: WW
authors.lastname: Lin
mesh_terms: D000818:Animals; D001596:Benzylamines / Q000494:pharmacology; D001952:Bridged-Ring Compounds / Q000494:pharmacology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D002460:Cell Line; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D051550:I-kappa B Kinase; D020672:I-kappa B Proteins / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D017737:Macrophages, Peritoneal / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism*; D016328:NF-kappa B / Q000187:drug effects / Q000378:metabolism; D009636:Norbornanes; D010766:Phosphorylation / Q000187:drug effects; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000187:drug effects* / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D018048:Receptors, Purinergic P2 / Q000502:physiology; D013449:Sulfonamides / Q000494:pharmacology; D019284:Thapsigargin / Q000494:pharmacology; D013859:Thiocarbamates; D013871:Thiones / Q000494:pharmacology; D013997:Time Factors; D051996:Transcription Factor RelA; D014544:Uridine Triphosphate / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases; D000096926:Benzenesulfonamides
chemical_list: D001596:Benzylamines; D001952:Bridged-Ring Compounds; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D004791:Enzyme Inhibitors; D005419:Flavonoids; D051550:I-kappa B Kinase; D020672:I-kappa B Proteins; D007093:Imidazoles; D007211:Indoles; D008070:Lipopolysaccharides; D020928:Mitogen-Activated Protein Kinases; D016328:NF-kappa B; D009636:Norbornanes; D011493:Protein Kinase C; D017346:Protein Serine-Threonine Kinases; D011725:Pyridines; D018048:Receptors, Purinergic P2; D013449:Sulfonamides; D019284:Thapsigargin; D013859:Thiocarbamates; D013871:Thiones; D051996:Transcription Factor RelA; D014544:Uridine Triphosphate; D048051:p38 Mitogen-Activated Protein Kinases; C072105:KN 93; D000096926:Benzenesulfonamides; C046498:tricyclodecane-9-yl-xanthogenate; C093642:SB 203580; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; C064758:Ro 31-8220