Cannabinoid CB2 Receptors in Health and Disease

Marijuana has been used for thousands of years to affect human health. Dissecting the peripheral effects from the central psychotropic effects has revealed a complex interplay between cannabinoids, endocannabinoids and their receptors. This review examines recent advances in understanding the expression, regulation and utilization of the CB2 receptor. Here we highlight the molecular aspects of the CB2 receptor, CB2 receptor signaling and new ligands for this receptor. We focus in the rest of the review on recent findings in the immune system, the gastrointestinal tract and liver, the brain and the cardiovascular system and airways as examples of areas where new developments in our understanding of the CB2 receptor have occurred. Early studies focused on expression of this receptor under baseline physiologic conditions; however, perturbations such as those that occur during inflammation, ischemia/reperfusion injury and cancer are revealing a critical role for the CB2 receptor in regulating these disease processes amongst others. As a result, the CB2 receptor is an appealing therapeutic target as well as a useful tool for shedding new light on physiological regulatory processes throughout the body.