Association between alcoholism and the gene encoding the endocannabinoid synthesizing enzyme diacylglycerol lipase alpha in the Japanese population

The endocannabinoid system has been recognized to be involved in neuropsychiatric diseases. 2-arachidonoyl glycerol (2-AG) is one of the two main endocannabinoids, and their regulation could play roles in disorders under environmental influence. This study investigated the involvement of the 2-AG biosynthesizing enzyme diacylglycerol lipase alpha (DAGLA) in the pathogenesis of alcoholism. We investigated a possible association between alcoholism and single nucleotide polymorphisms (SNPs) of the human DAGLA gene in the Japanese population. To discern any environmental influences on Dagla function in an animal study, the Dagla gene expression in the brain from stressed model mice was analyzed. The SNPs, including missense polymorphism Pro899Leu in the DAGLA gene, showed associations with alcoholism in the Japanese population. Dagla expression in mice was found to be influenced by chronic mild stress and by the acquisition of alcohol preference. Our findings indicated the involvement of DAGLA in alcoholism, possibly by its genetic dysfunction and also by the influence of stress.