AUTHOR=Kuipers Eline N. , Kantae Vasudev , Maarse Boukje C. Eveleens , van den Berg Susan M. , van Eenige Robin , Nahon Kimberly J. , Reifel-Miller Anne , Coskun Tamer , de Winther Menno P. J. , Lutgens Esther , Kooijman Sander , Harms Amy C. , Hankemeier Thomas , van der Stelt Mario , Rensen Patrick C. N. , Boon Mariëtte R. TITLE=High Fat Diet Increases Circulating Endocannabinoids Accompanied by Increased Synthesis Enzymes in Adipose Tissue JOURNAL=Frontiers in Physiology VOLUME=9 YEAR=2019 URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2018.01913 DOI=10.3389/fphys.2018.01913 ISSN=1664-042X ABSTRACT=

The endocannabinoid system (ECS) controls energy balance by regulating both energy intake and energy expenditure. Endocannabinoid levels are elevated in obesity suggesting a potential causal relationship. This study aimed to elucidate the rate of dysregulation of the ECS, and the metabolic organs involved, in diet-induced obesity. Eight groups of age-matched male C57Bl/6J mice were randomized to receive a chow diet (control) or receive a high fat diet (HFD, 45% of calories derived from fat) ranging from 1 day up to 18 weeks before euthanasia. Plasma levels of the endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide (N-arachidonoylethanolamine, AEA), and related N-acylethanolamines, were quantified by UPLC-MS/MS and gene expression of components of the ECS was determined in liver, muscle, white adipose tissue (WAT) and brown adipose tissue (BAT) during the course of diet-induced obesity development. HFD feeding gradually increased 2-AG (+132% within 4 weeks, P < 0.05), accompanied by upregulated expression of its synthesizing enzymes Daglα and β in WAT and BAT. HFD also rapidly increased AEA (+81% within 1 week, P < 0.01), accompanied by increased expression of its synthesizing enzyme Nape-pld, specifically in BAT. Interestingly, Nape-pld expression in BAT correlated with plasma AEA levels (R2 = 0.171, β = 0.276, P < 0.001). We conclude that a HFD rapidly activates adipose tissue depots to increase the synthesis pathways of endocannabinoids that may aggravate the development of HFD-induced obesity.