title: Coupling of Ca(2+) to CREB activation and gene expression in intact cerebral arteries from mouse : roles of ryanodine receptors and voltage-dependent Ca(2+) channels.
abstract: Pathological changes of the vasculature are characterized by changes in Ca(2+) handling and alterations in gene expression. In neurons and other cell types, [Ca(2+)](i) often drives changes in gene expression. However, the relationship between Ca(2+) signaling and gene expression in vascular smooth muscle is not well understood. This study examines the ability of Ca(2+) influx through voltage-dependent, L-type Ca(2+) channels (VDCCs) and Ca(2+) release through ryanodine receptors (RyRs) to activate the transcription factor, cAMP-responsive element binding protein (CREB), and increase c-fos levels in intact cerebral arteries. Membrane depolarization increased the fraction of nuclei staining for phosphorylated CREB (P-CREB) and levels of c-fos mRNA in intact mouse cerebral arteries. Ryanodine, which inhibits RyRs, increased P-CREB staining and c-fos levels. Forskolin, an activator of adenylyl cyclase, and sodium nitroprusside, an NO donor, increased P-CREB and c-fos levels. Nisoldipine, an inhibitor of VDCCs, reversed the effects of depolarization and ryanodine on P-CREB and c-fos levels, but not the effects of forskolin or sodium nitroprusside. Inhibition of Ca(2+)/calmodulin-dependent protein kinase (CaM kinase) blocked increases in P-CREB and c-fos levels seen with membrane depolarization, suggesting that CaM kinase has an important role in the pathway leading from Ca(2+) influx to CREB-mediated changes in c-fos levels. Our data suggest that membrane depolarization increases [Ca(2+)](i) through activation of VDCCs, leading to increased P-CREB and c-fos, and that RyRs have a profound effect on this pathway by indirectly regulating Ca(2+) entry through VDCCs. These results provide the first evidence of Ca(2+) regulation of CREB and c-fos in arterial smooth muscle.
authors.affiliation: Department of Pharmacology, University of Vermont, Burlington, VT, USA.
authors.forename: L
authors.initials: L
authors.lastname: Cartin
authors.forename: K M
authors.initials: KM
authors.lastname: Lounsbury
authors.forename: M T
authors.initials: MT
authors.lastname: Nelson
mesh_terms: D000818:Animals; D001596:Benzylamines / Q000494:pharmacology; D002118:Calcium / Q000502:physiology*; D020746:Calcium Channels, L-Type / Q000187:drug effects / Q000502:physiology*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D002147:Calmodulin / Q000037:antagonists & inhibitors; D005576:Colforsin / Q000494:pharmacology; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D004110:Diltiazem / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D016762:Genes, fos; D007093:Imidazoles / Q000494:pharmacology; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000502:physiology; D051379:Mice; D020768:Middle Cerebral Artery / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D015737:Nisoldipine / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D020769:Posterior Cerebral Artery / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D011188:Potassium / Q000494:pharmacology; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D019837:Ryanodine Receptor Calcium Release Channel / Q000187:drug effects / Q000502:physiology*; D013449:Sulfonamides / Q000494:pharmacology; D014158:Transcription, Genetic; D000096926:Benzenesulfonamides
chemical_list: D001596:Benzylamines; D002118:Calcium; D020746:Calcium Channels, L-Type; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D002147:Calmodulin; D005576:Colforsin; D017362:Cyclic AMP Response Element-Binding Protein; D004110:Diltiazem; D004791:Enzyme Inhibitors; D007093:Imidazoles; D015737:Nisoldipine; D009599:Nitroprusside; D011188:Potassium; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D019837:Ryanodine Receptor Calcium Release Channel; D013449:Sulfonamides; C072105:KN 93; D000096926:Benzenesulfonamides; C031938:calmidazolium