A Dysregulated Endocannabinoid-Eicosanoid Network Supports Pathogenesis in a Mouse Model of Alzheimer's Disease

Although inflammation in the brain is meant as a defense mechanism against neurotoxic stimuli, increasing evidence suggests that uncontrolled, chronic and persistent inflammation contributes to neurodegeneration. Most neurodegenerative diseases have now been associated with chronic inflammation, including Alzheimer’s disease (AD). Whether anti-inflammatory approaches can be used to treat AD, however, is a major unanswered question. We recently demonstrated that monoacylglycerol lipase (MAGL) hydrolyzes endocannabinoids to generate the primary arachidonic acid pool for neuroinflammatory prostaglandins. In this study, we show that genetic inactivation of MAGL attenuates neuroinflammation and lowers amyloid βlevels and plaques, in an AD mouse model. We also find that pharmacological blockade of MAGL recapitulates the cytokine lowering effects through reduced prostaglandin production, rather than enhanced endocannabinoid signaling. Our findings thus reveal a heretofore unrecognized role of MAGL in modulating neuroinflammation and amyloidosis in AD etiology, and put forth MAGL inhibitors as a potential next-generation strategy for combatting AD.