Inflammation and Nitro-oxidative Stress as Drivers of Endocannabinoid System Aberrations in Mood Disorders and Schizophrenia.

The endocannabinoid system (ECS) is composed of the endocannabinoid ligands anandamide (AEA) and 2-arachidonoylgycerol (2-AG), their target cannabinoid receptors (CB and CB) and the enzymes involved in their synthesis and metabolism (N-acyltransferase and fatty acid amide hydrolase (FAAH) in the case of AEA and diacylglycerol lipase (DAGL) and monoacylglycerol lipase (MAGL) in the case of 2-AG). The origins of ECS dysfunction in major neuropsychiatric disorders remain to be determined, and this paper explores the possibility that they may be associated with chronically increased nitro-oxidative stress and activated immune-inflammatory pathways, and it examines the mechanisms which might be involved. Inflammation and nitro-oxidative stress are associated with both increased CB expression, via increased activity of the NADPH oxidases NOX4 and NOX1, and increased CNR1 expression and DNA methylation; and CB upregulation via increased pro-inflammatory cytokine levels, binding of the transcription factor Nrf2 to an antioxidant response element in the CNR2 promoter region and the action of miR-139.