The cannabinoid agonist WIN 55,212-2 inhibits TNF-α-induced neutrophil transmigration across ECV304 cells

Cannabinoids are known to possess both anti-inflammatory and neuroprotective effects. In the present study, we have investigated the ability of cannabinoids to inhibit the transmigration of neutrophils in response to chemotaxic stimuli. The cannabinoid receptor agonist WIN 55,212-2 ((R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl)-pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl]-1-naphthalenylmethanone mesylate) significantly decreased the number of migrating neutrophils across a monolayer of tumour necrosis factor alpha (TNF-α) activated ECV304 cells at concentrations ≥ 1 μM. In contrast, the agonists HU210 and CP 55,940 (0.01–1 μM) and the endocannabinoid anandamide (0.1–10 μM) were without significant effect on the response to TNF-α. The ability of WIN 55,212-2 to reduce the neutrophil transmigration was still seen in the presence of the cannabinoid CB1 receptor antagonist/inverse agonist AM251 (0.1–1 μM) and the cannabinoid CB2 receptor antagonist/inverse agonist AM630 (0.1–1 μM). TNF-α treatment of ECV304 cells caused release of interleukin-8 (IL-8), but WIN 55,212-2 did not affect either the ability of neutrophils to migrate across chemotaxis plates in response to an IL-8 stimulus, or to change the percentage of CXC 1 and CXC 2 receptors expressed by the neutrophils. WIN 55,212-2 at a concentration of 1 μM, but not at lower concentrations, produced a significant inhibition of IL-8 release from ECV304 cells in response to TNF-α-stimulation. Thus WIN 55,212-2 reduces the transmigration of neutrophils across a monolayer of TNF-α-activated ECV304 cells by an indirect action upon the release of IL-8 and/or other chemokine release from the ECV304 cells, and that this effect is brought about mainly by a cannabinoid CB receptor-independent mechanism.