Cannabinoid regulation of nitric oxide synthase I (nNOS) in neuronal cells.
In our previous studies, CB(1) cannabinoid receptor agonists stimulated production of cyclic GMP and translocation of nitric oxide (NO)-sensitive guanylyl cyclase in neuronal cells (Jones et al., Neuropharmacology 54:23-30, 2008). The purpose of these studies was to elucidate the signal transduction of cannabinoid-mediated neuronal nitric oxide synthase (nNOS) activation in neuronal cells. Cannabinoid agonists CP55940 (2-[(1S,2R,5S)-5-hydroxy-2-(3-hydroxypropyl) cyclohexyl]-5-(2-methyloctan-2-yl)phenol), WIN55212-2 (R(+)-[2,3-dihydro-5-methyl-3-[(morpholinyl)methyl]pyrrolo[1,2,3-de]-1,4-benzoxazinyl]-(1-naphthalenyl)methanone mesylate), and the metabolically stable analog of anandamide, (R)-(+)-methanandamide stimulated NO production in N18TG2 cells over a 20-min period. Rimonabant (N-(piperidin-lyl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-H-pyrazole-3-carboxamide), a CB(1) receptor antagonist, partially or completely curtailed cannabinoid-mediated NO production. Inhibition of NOS activity (N ( G )-nitro-L: -arginine) or signaling via Gi/o protein (pertussis toxin) significantly limited NO production by cannabinoid agonists. Ca(2+) mobilization was not detected in N18TG2 cells after cannabinoid treatment using Fluo-4 AM fluorescence. Cannabinoid-mediated NO production was attributed to nNOS activation since endothelial NOS and inducible NOS protein and mRNA were not detected in N18TG2 cells. Bands of 160 and 155 kDa were detected on Western blot analysis of cytosolic and membrane fractions of N18TG2 cells, using a nNOS antibody. Chronic treatment of N18TG2 cells with cannabinoid agonists downregulated nNOS protein and mRNA as detected using Western blot analysis and real-time polymerase chain reaction, respectively. Cannabinoid agonists stimulated NO production via signaling through CB(1) receptors, leading to activation of Gi/o protein and enhanced nNOS activity. The findings of these studies provide information related to cannabinoid-mediated NO signal transduction in neuronal cells, which has important implications in the ongoing elucidation of the endocannabinoid system in the nervous system.
Neuroscience of Drug Abuse Research Program, Julius L. Chambers Biomedical/Biotechnology Research Institute, North Carolina Central University, Durham, NC 27707, USA.
Skyla T
ST
Carney
Michael L
ML
Lloyd
Shanta E
SE
MacKinnon
Doshandra C
DC
Newton
Jenelle D
JD
Jones
Allyn C
AC
Howlett
Derek C
DC
Norford
D001095:Arachidonic Acids / Q000494:pharmacology; D048588:Benzoxazines / Q000494:pharmacology; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism; D063385:Cannabinoid Receptor Modulators / Q000494:pharmacology*; D002186:Cannabinoids / Q000494:pharmacology; D002460:Cell Line; D006152:Cyclic GMP / Q000378:metabolism; D003511:Cyclohexanols / Q000494:pharmacology; D063388:Endocannabinoids; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006162:Guanylate Cyclase / Q000378:metabolism; D006801:Humans; D009025:Morpholines / Q000494:pharmacology; D009281:Naphthalenes / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000201:enzymology*; D052248:Nitric Oxide Synthase Type I / Q000037:antagonists & inhibitors / Q000378:metabolism*; D053284:Polyunsaturated Alkamides / Q000494:pharmacology; D043884:Receptor, Cannabinoid, CB1 / Q000819:agonists; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects
D001095:Arachidonic Acids; D048588:Benzoxazines; D063385:Cannabinoid Receptor Modulators; D002186:Cannabinoids; D003511:Cyclohexanols; D063388:Endocannabinoids; D004791:Enzyme Inhibitors; D009025:Morpholines; D009281:Naphthalenes; D053284:Polyunsaturated Alkamides; D043884:Receptor, Cannabinoid, CB1; C088155:methanandamide; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone; C054649:3-(2-hydroxy-4-(1,1-dimethylheptyl)phenyl)-4-(3-hydroxypropyl)cyclohexanol; D052248:Nitric Oxide Synthase Type I; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D002118:Calcium; C078814:anandamide