title: Nitric oxide enhances increase in cytosolic Ca(2+) and promotes nicotine-triggered MAPK pathway in PC12 cells.
abstract: The purpose of this study was to investigate the roles of neuronal nitric oxide synthase (nNOS), Ca(2+)/calmodulin (CaM)-dependent protein kinases (CaMKs), and protein kinase C (PKC) in nicotine-induced extracellular signal-regulated kinases 1 and 2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK) activation. Treatment with nicotine stimulated ERK1/2 and p38 MAPK phosphorylation in the PC12 cells expressing nNOS (NPC12 cells) as compared with that in control PC12 cells. An inhibitor of L-type voltage-sensitive Ca(2+) channel suppressed the nicotine-induced phosphorylation of p38 MAPK. The inhibition of CaMK-kinase, the upstream activator of CaMKI and CaMKIV, did not inhibit the enhanced their phosphorylation. ERK1/2 phosphorylation was attenuated by inhibitors of p38 MAPK, PKC, and MAPK-kinase 1/2, indicating the involvement of these protein kinases upstream of ERK1/2. Furthermore, we found that nNOS expression enhances the nicotine-induced increase in the intracellular concentration of Ca(2+), using the Ca(2+)-sensitive fluorescent probe Fura2. These data suggest that NO promotes nicotine-triggered Ca(2+) transient in PC12 cells to activate possibly CaMKII, leading to sequential phosphorylation of p38 MAPK and ERK1/2.
authors.affiliation: Department of Pharmacology, High Technology Research Center, Showa Pharmaceutical University, Machida, Tokyo 194-8543, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Kajiwara
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Tsuchiya
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Takata
authors.forename: Mayumi
authors.initials: M
authors.lastname: Nyunoya
authors.forename: Naohito
authors.initials: N
authors.lastname: Nozaki
authors.forename: Hideshi
authors.initials: H
authors.lastname: Ihara
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Watanabe
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009538:Nicotine / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I / Q000378:metabolism; D016716:PC12 Cells; D010766:Phosphorylation / Q000187:drug effects; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats
chemical_list: D009569:Nitric Oxide; D009538:Nicotine; C496320:NOS1 protein, human; D052248:Nitric Oxide Synthase Type I; D011493:Protein Kinase C; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D002118:Calcium
keywords: Ca(2+)/calmodulin-dependent protein kinase; CaM; CaMK; Calmodulin-dependent protein kinase; ERK; ERK1/2; L-VSCC; L-type voltage-sensitive Ca(2+) channel; MAPK; NO; PC12 cells; PKC; calmodulin; extracellular signal-regulated kinase; mitogen-activated protein kinase; nAChR; nNOS; neuronal nitric oxide synthase; nicotinic acetylcholine receptor; nitric oxide; p38 MAPK; protein kinase C