title: Contribution of extracellular signal-regulated kinase to UTP-induced interleukin-6 biosynthesis in HaCaT keratinocytes.
abstract: UTP causes interleukin (IL)-6 production via mRNA expression through P2Y(2)/P2Y(4) receptors in human HaCaT keratinocytes. In the present study, we analyzed the mechanism of UTP-induced IL-6 production in these cells. UTP, an agonist of P2Y(2)/P2Y(4) receptors, induced phosphorylation of extracellular signal-regulated kinase (ERK) in a concentration- and time-dependent manner. PD98059, a MEK (mitogen-activated protein kinase kinase) inhibitor, and BAPTA-AM [O,O'-bis(2-aminophenyl)ethyleneglycol-N,N,N',N'-tetraacetic acid, tetraacetoxymethyl ester], an intracellular Ca(2+) chelator, reduced UTP-induced ERK phosphorylation and IL-6 mRNA expression. 2-APB [(2-aminoethoxy)diphenylborane], an inositol 1,4,5-trisphosphate (IP(3))-receptor antagonist, inhibited UTP-induced IL-6 mRNA expression; and the action of A23187, a Ca(2+) ionophore, resembled the action of UTP. In contrast, protein kinase C (PKC) downregulation and pertussis toxin did not affect UTP-induced IL-6 mRNA expression, suggesting that PKC and G(i) are not involved in the UTP-induced IL-6 production. However, AG1478, an epidermal growth factor (EGF)-receptor inhibitor, partially decreased UTP-induced ERK phosphorylation and IL-6 expression. These results suggest that UTP-induced IL-6 production is in part mediated via phosphorylation of ERK through G(q/11)/IP(3)/[Ca(2+)](i) and transactivation of the EGF receptor.
authors.affiliation: Department of Cellular Signaling, Graduate School of Pharmaceutical Sciences, Tohoku University, Aramaki, Sendai, Japan.
authors.forename: Daisaku
authors.initials: D
authors.lastname: Kobayashi
authors.forename: Satoko
authors.initials: S
authors.lastname: Ohkubo
authors.forename: Norimichi
authors.initials: N
authors.lastname: Nakahata
mesh_terms: D002121:Calcium Channel Blockers / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects; D002478:Cells, Cultured; D002614:Chelating Agents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000037:antagonists & inhibitors / Q000378:metabolism; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000378:metabolism; D006801:Humans; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000037:antagonists & inhibitors / Q000378:metabolism; D015850:Interleukin-6 / Q000096:biosynthesis*; D007476:Ionophores / Q000494:pharmacology; D015603:Keratinocytes / Q000187:drug effects* / Q000378:metabolism; D037342:Pertussis Toxin / Q000494:pharmacology; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D058910:Purinergic P2 Receptor Agonists; D012333:RNA, Messenger / Q000096:biosynthesis; D018048:Receptors, Purinergic P2; D058473:Receptors, Purinergic P2Y2; D013997:Time Factors; D014544:Uridine Triphosphate / Q000494:pharmacology*
chemical_list: D002121:Calcium Channel Blockers; D002614:Chelating Agents; D053496:Inositol 1,4,5-Trisphosphate Receptors; D015850:Interleukin-6; D007476:Ionophores; C546385:P2RY2 protein, human; D047428:Protein Kinase Inhibitors; D058910:Purinergic P2 Receptor Agonists; D012333:RNA, Messenger; D018048:Receptors, Purinergic P2; D058473:Receptors, Purinergic P2Y2; C104749:purinoceptor P2Y4; D037342:Pertussis Toxin; D066246:ErbB Receptors; D011493:Protein Kinase C; D048049:Extracellular Signal-Regulated MAP Kinases; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D014544:Uridine Triphosphate