Association of plasma and CSF cytochrome P450, soluble epoxide hydrolase and ethanolamides metabolism with Alzheimer’s disease

Abstract Alzheimer’s disease shares inflammatory origin with cardiometabolic disorders. Lipid mediators, including oxylipins, endocannabinoids, bile acids and steroids are potent regulators of inflammation, energy metabolism and cell proliferation with well-established involvement in cardiometabolic diseases. However, their role in Alzheimer’s disease is poorly understood. In the current study we provide comprehensive analysis of plasma and CSF lipid mediators in a case-control comparison of patients with Alzheimer’s disease, utilizing a targeted quantitative mass spectrometry approach. In both plasma and CSF, we observed Alzheimer’s disease patients to have elevated components of cytochrome P450/soluble epoxide hydrolase pathway and lower levels of fatty acids ethanolamides, when compared to the healthy controls. Multivariate analysis revealed that circulating metabolites of soluble epoxide hydrolase together with ethanolamides are strong and independent predictors for Alzheimer’s disease. Both metabolic pathways are potent regulators of inflammation with soluble epoxide hydrolase being reported to be upregulated in the brains of Alzheimer’s disease patients. This study provides further evidence for the involvement of inflammation in Alzheimer’s disease and argues for further research into the role of the cytochrome P450/soluble epoxide hydrolase pathway and fatty acid ethanolamides in this disorder. Further, these findings suggest that a combined pharmacological intervention targeting both metabolic pathways may have therapeutic benefits for Alzheimer’s disease.