Selective cannabinoid CB1 receptor-mediated inhibition of inducible nitric oxide synthase protein expression in C6 rat glioma cells.
We have studied the effects of two cannabinoid receptor agonists, WIN 55,212-2 and cannabinol, on nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) expression in the C6 glioma cell line. After 24 h of lipopolysaccharide (LPS) (1 microg/mL) and interferon-gamma (IFN-gamma) (300 U/mL) stimulation, a significant increase in NO production, evaluated as nitrite, was observed in the culture medium. WIN 55,212-2 (0.1-10000 nM) and cannabinol (0.3-30000 nM), dose-dependently inhibited nitrite production showing a different potency (WIN 55,212-2 EC(50): 4.2 nM; cannabinol EC(50): 700 nM). WIN 55,212-2 (100 nM), given concomitantly to the stimulus also inhibited iNOS expression but had no effect when added to the cells 2 h after LPS/IFN-gamma, indicating a possible interference at the protein synthesis level or at an earlier step, as gene transcription. The cannabinoid CB1 receptor antagonist, SR141716A (0.1-100 nM), but not the cannabinoid CB2 receptor antagonist, SR144528 (0.1-100 nM), reduced in a dose-related manner WIN 55,212-2-and cannabinol-induced inhibition of nitrite production. SR141161A also reversed the WIN 55,212-2-induced inhibition of iNOS expression. These data suggest that selective cannabinoid CB1 receptor activation, by inhibiting iNOS expression and NO overproduction in glial cells, might be helpful in NO-mediated inflammation leading to neurodegeneration.
Esposito
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Department of Experimental Pharmacology, University of Naples 'Federico II', Naples, Italy.
Izzo
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Di Rosa
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Iuvone
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D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D048588:Benzoxazines; D015153:Blotting, Western; D002187:Cannabinol / Q000494:pharmacology*; D002458:Cell Fractionation; D004305:Dose-Response Relationship, Drug; D015151:Immunoblotting; D007371:Interferon-gamma / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D009025:Morpholines / Q000494:pharmacology*; D009281:Naphthalenes / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II; D009573:Nitrites / Q000378:metabolism; D051381:Rats; D043885:Receptor, Cannabinoid, CB2; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D000700:Analgesics; D048588:Benzoxazines; C469526:Cnr2 protein, rat; D008070:Lipopolysaccharides; D009025:Morpholines; D009281:Naphthalenes; D009573:Nitrites; D043885:Receptor, Cannabinoid, CB2; D043882:Receptors, Cannabinoid; D011955:Receptors, Drug; D009569:Nitric Oxide; C070417:(3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone; D002187:Cannabinol; D007371:Interferon-gamma; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat