Cannabinoid-2 receptor limits inflammation,oxidative/nitrosative stress,and cell death in nephropathy

Cisplatin is an important chemotherapeutic agent; however, its nephrotoxicity limits its clinical use. Enhanced inflammatory response and oxidative/nitrosative stress seem to play a key role in the development of cisplatin-induced nephropathy. Activation of cannabinoid-2 (CB₂) receptors with selective agonists exerts anti-inflammatory and tissue-protective effects in various disease models. We have investigated the role of CB₂ receptors in cisplatin-induced nephrotoxicity using the selective CB₂ receptor agonist HU-308 and CB₂ knockout mice. Cisplatin significantly increased inflammation (leukocyte infiltration, CXCL1/2, MCP-1, TNFα, and IL-1β levels) and expression of adhesion molecule ICAM-1 and superoxide-generating enzymes NOX2, NOX4, and NOX1 and enhanced ROS generation, iNOS expression, nitrotyrosine formation, and apoptotic and poly(ADP-ribose) polymerase-dependent cell death in the kidneys of mice, associated with marked histopathological damage and impaired renal function (elevated serum BUN and creatinine levels) 3 days after the administration of the drug. CB₂ agonist attenuated the cisplatin-induced inflammatory response, oxidative/nitrosative stress, and cell death in the kidney and improved renal function, whereas CB₂ knockouts developed enhanced inflammation and tissue injury. Thus, the endocannabinoid system, through CB₂ receptors, protects against cisplatin-induced kidney damage by attenuating inflammation and oxidative/nitrosative stress, and selective CB₂ agonists may represent a promising novel approach to preventing this devastating complication of chemotherapy.