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

Abstract

Here, we show a novel pharmacology for inhibition of human neutrophil migration by endocannabinoids, phytocannabinoids, and related compounds. The endocannabinoids virodhamine and N-arachidonoyl dopamine are potent inhibitors of N-formyl-L-methionyl-L-leucyl-L-phenylalanine-induced migration of human neutrophils, with IC 50 values of 0.2 and 8.80 nM, respectively. The endocannabinoid anandamide inhibits human neutrophil migration at nanomolar concentrations in a biphasic manner. The phytocannabinoid (Ϫ)-cannabidiol is a partial agonist, being ϳ40 fold more potent than (ϩ)-cannabidiol; abnormal-cannabidiol is a full agonist. Furthermore, the abnormal-cannabidiol (CBD) analog) inhibits migration, with an IC 50 value of 33 nM. This reported profile of agonist efficacy and potency parallels with the pharmacology of the novel "abnormal-cannabidiol" receptor or a related orphan G protein-coupled receptor, which are already known to modulate cell migration. Although having no effect alone, Narachidonoyl L-serine attenuated inhibition of human neutrophil migration induced by anandamide, virodhamine, and abnormal-CBD. Our data also suggest that there is crosstalk/negative co-operativity between the cannabinoid CB 2 receptor and this novel target: CB 2 receptor antagonists significantly enhance the inhibition observed with anandamide and virodhamine. This study reveals that certain endogenous lipids, phytocannabinoids, and related ligands are potent inhibitors of human neutrophil migration, and it implicates a novel pharmacological target distinct from cannabinoid CB 1 and CB 2 receptors; this target is antagonized by the endogenous compound N-arachidonoyl L-serine. Furthermore, our findings have implications for the potential pharmacological manipulation of elements of the endocannabinoid system for the treatment of various inflammatory conditions. The endocannabinoid system comprises two known receptors (CB 1 and CB 2 ); a family of endogenous ligands (endocannabinoids); and specific molecular machinery for the synthesis, transport, and inactivation of these ligands (Pertwee and Ross, 2002). The most studied endocannabinoids are arachidonoylethanolamide (AEA), also known as anandamide, and 2-arachidonoyl glycerol (2-AG), both of which are synthesized on demand, and they are rapidly hydrolyzed by the enzymes fatty acid amide hydrolase and monoacyl glycerol lipase, respectively (Fowler et al., 2005). There are a number of additional endocannabinoids; these include N-arachidonoyl

Clarifying CB2 receptor-dependent and independent effects of THC on human lung epithelial cells

“…These results may also suggest that non-CB receptor mechanisms play more prominent roles as [THC] is increased. Such non-CB receptor mechanisms have also recently been implicated in cannabiniod-mediated inhibition of human neutrophil chemotaxis (McHugh et al, 2008).…”

From Phytocannabinoids to Cannabinoid Receptors and Endocannabinoids: Pleiotropic Physiological and Pathological Roles Through Complex Pharmacology

“…The anti-inflammatory and cytokine modulatory properties of CBD (336,419,551) are such that its administration results in attenuation of various autoimmune conditions in animal models, including experimental autoimmune encephalomyelitis (447), rheumatoid arthritis (524), colitis (89), diabetes (912), and psoriasis (916). Indeed, CBD has been suggested as a promising treatment also for autoimmune myocarditis and possibly other autoimmune disorders, and it might be useful for organ transplantation (466).…”

Endocannabinoid functions controlling neuronal specification during brain development

“…Recent evidence indicates that eCBs modulate, through cell type-specific receptor systems and downstream signaling mechanisms, the chemotaxis of various cell types, including glial cells (Walter et al, 2003), neurons (Berghuis et al, 2005), immune cells (Kurihara et al, 2006;McHugh et al, 2007;Miller et al, 2007), smooth muscle cells (Rajesh et al, 2007), cancer cells (Ghosh et al, 2006;Preet et al, 2007) and HEK293 cells (Song et al, 2000). It is important to note that eCBs often interact with other signaling systems, including neurotrophins (Berghuis et al, 2005), growth factors (Preet et al, 2007), and inflammatory cytokines (Rajesh et al, 2007) to induce cell migration.…”