A Novel Cannabinoid Peripheral Cannabinoid Receptor-Selective Inverse Agonist Blocks Leukocyte Recruitment in Vivo

Abstract

The expression of the cannabinoid peripheral cannabinoid receptor (CB 2 ) receptor on peripheral immune cells suggests that compounds specific for CB 2 might be effective anti-inflammatory agents. In this report, we present the initial biological profiling of a novel triaryl bis-sulfone, Sch.336, which is selective for the human cannabinoid CB 2 receptor (hCB 2 ). Sch.336 is an inverse agonist at hCB 2 , as shown by its ability to decrease guanosine 5Ј-3-O-(thio)triphosphate (GTP␥S) binding to membranes containing hCB 2 , by the ability of GTP␥S to left-shift Sch.336 binding to hCB 2 in these membranes, and by the compound's ability to increase forskolin-stimulated cAMP levels in CHO cells expressing hCB 2 . In these systems, Sch.336 displays a greater potency than that reported for the CB 2 In vitro, Sch.336 impairs the migration of CB 2 -expressing recombinant cell lines to the cannabinoid agonist 2-arachidonylglycerol. In vivo, the compound impairs migration of cells to cannabinoid agonist HU210 [(6aR)-trans-3-(1,1-dimethylheptyl)-6a,7,10,10a-tetrahydro-1-hydroxy-6,6-dimethyl-6H-dibenzo [b,d] pyran-9-methanol]. Oral administration of the Sch.336 significantly inhibited leukocyte trafficking in several rodent in vivo models, induced either by specific chemokines or by antigen challenge. Finally, oral administration of Sch.336 blocked ovalbumin-induced lung eosinophilia in mice, a disease model for allergic asthma. We conclude that selective cannabinoid CB 2 inverse agonists may serve as novel immunomodulatory agents in the treatment of a broad range of acute and chronic inflammatory disorders in which leukocyte recruitment is a hallmark of disease pathology.The identification of a second cannabinoid receptor present primarily in peripheral immune tissues and cells (Munro et al., 1993) suggested an immunomodulatory role for endocannabinoids independent of the effects mediated by their interaction with the "brain" cannabinoid CB 1 receptor. Libraries of selective compounds now exist, based either on the structure of known ligands for the cannabinoid receptors or on results of random compound library screening (Huffman, 2000). With the help of CB 2 -specific compounds and by characterization of a CB 2 Ϫ/Ϫ mouse strain (Buckley et al., 2000), Article, publication date, and citation information can be found at

Inhibition of Human Neutrophil Chemotaxis by Endogenous Cannabinoids and Phytocannabinoids: Evidence for a Site Distinct from CB1and CB2

“…Furthermore, autoactivation may underlie the lack of significant stimulation of neutrophil migration by the CB 2 receptor agonists 2-AG, CP55940, JWH-133, and JWH015 (Kurihara et al, 2006; this study). In line with our findings, Lunn et al (2006) have demonstrated that CB 2 receptor inverse agonists inhibit leukocyte migration both in vivo and in vitro, and the level of effect is proportional to the degree of inverse efficacy.…”

Involvement of the Cannabinoid CB2 Receptor and Its Endogenous Ligand 2-Arachidonoylglycerol in Oxazolone-Induced Contact Dermatitis in Mice

“…We also found that SR144528 markedly suppressed the ear swelling induced by dinitrofluorobenzene in mice (S. Oka and T. Sugiura, unpublished results). In contrast, Jan et al (51) and Lunn et al (52) demonstrated that ⌬ 9 -tetrahydrocannabinol and several CB2 receptor antagonists suppressed inflammatory reactions in the airway. These experimental results are generally consistent with the experimental results obtained in the present study and previously (30), although no information is available on 2-AG in these studies by other investigators (50 -52).…”

Characterizing Cannabinoid CB2 Receptor Ligands Using DiscoveRx PathHunter™ β-Arrestin Assay

“…This system, insensitive to the pharmacology of potential hit compounds, resulted in the identification of the triaryl bis sulfone class of cannabinoid CB 2 receptor-specific inverse agonist. 7 Efforts to specifically identify cannabinoid CB 2 receptorspecific agonists utilized a recombinant cell-based cAMP competitive immunoassay, the LANCE ™ cAMP Detection Kit from PerkinElmer. To achieve the robustness required for library screening, the recombinant cell biosensor was treated with the kinase inhibitor tangeretin, 8 which improved the signal-to-background ratio achieved using this platform.…”