The Endocannabinoid System Protects Rat Glioma Cells Against HIV-1 Tat Protein-induced Cytotoxicity

Autor: Teresa Iuvone, Alessia Ligresti, Angelo A. Izzo, Menotti Ruvo, Tiziana Bisogno, Vincenzo Di Marzo, Giuseppe Esposito, Massimo Di Rosa
Rok vydání: 2002
Předmět:
Zdroj: Journal of Biological Chemistry. 277:50348-50354
ISSN: 0021-9258
DOI: 10.1074/jbc.m207170200
Popis: Cannabinoids modulate nitric oxide (NO) levels in cells of the central nervous system. Here we studied the effect of cannabinoid CB1 and CB2receptor agonists on the release of NO and cell toxicity induced by the human immuno-deficiency virus-1 Tat protein (HIV-1 Tat) in rat glioma C6 cells. The CB1 and CB2 agonist WIN 55,212–2 inhibited the expression of inducible NO synthase (iNOS) and NO release caused by treatment of C6 cells with HIV-1 Tat and interferon-γ (IFN-γ). The effect of WIN 55,212–2 was uniquely due to CB1 receptors, as shown by experiments carried out with selective CB1 and CB2 receptor agonists and antagonists. CB1 receptor stimulation also inhibited HIV-1 Tat + IFN-γ-induced and NO-mediated cell toxicity. Moreover, cell treatment with HIV-1 Tat + IFN-γ induced a significant inhibition of CB1, but not CB2, receptor expression. This effect was mimicked by the NO donor GSNO, suggesting that the inhibition of CB1 expression was due to HIV-1 Tat + IFN-γ-induced NO overexpression. HIV-1 Tat + IFN-γ treatment also induced a significant inhibition of the uptake of the endocannabinoid anandamide by C6 cells with no effect on anandamide hydrolysis. These findings show that the endocannabinoid system, through the modulation of the l-arginine/NO pathway, reduces HIV-1 Tat-induced cytotoxicity, and is itself regulated by HIV-1 Tat.
Databáze: OpenAIRE