Investigating the alterations of endocannabinoidome signaling in the human small intestine in the context of obesity and type 2 diabetes.

Background: Human studies have linked obesity-related diseases, such as type-2 diabetes (T2D), to the modulation of endocannabinoid signaling. Cannabinoid CB1 and CB2 receptor activation by the endocannabinoids (eCBs) 2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine (AEA), both derived from arachidonic acid, play a role in homeostatic regulation. Other long chain fatty acid-derived endocannabinoid-like molecules have extended the metabolic role of this signaling system through other receptors. In this study, we aimed to assess in depth the interactions between the circulating and intestinal tone of this extended eCB system, or endocannabinoidome (eCBome), and their involvement in the pathogenesis of diabetes. Methods: Plasma and ileum samples were collected from subjects with obesity and harboring diverse degrees of insulin resistance or T2D, who underwent bariatric surgery. The levels of eCBome mediators and their congeners were then assessed by liquid chromatography coupled to tandem mass spectrometry, while gene expression was screened with qPCR arrays. Findings: Intestinal and circulating levels of eCBome mediators were higher in subjects with T2D. We found an inverse correlation between the intestinal and circulating levels of monoacylglycerols (MAGs). Additionally, we identified genes known to be implicated in both lipid metabolism and intestinal function that are altered by the context of obesity and glucose homeostasis. Interpretation: Although the impact of glucose metabolism on the eCBome remains poorly understood in subjects with advanced obesity state, our results suggest a strong causative link between altered glucose homeostasis and eCBome signaling in the intestine and the circulation.

A Study of the Differential Effects of Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) on Gene Expression Profiles of Stimulated Thp-1 Macrophages.

Background: An appropriate intake of omega-3 (n-3) fatty acids (FAs) such as eicosapentaenoic and docosahexaenoic acid (EPA/DHA) from marine sources is known to have anti-inflammatory effects. However, molecular mechanisms underlying their beneficial effects on health are not fully understood. The aim of the present study was to characterize gene expression profiles of THP-1 macrophages, incubated in either EPA or DHA and stimulated with lipopolysaccharide (LPS), a pro-inflammatory agent. Methods: THP-1 macrophages were incubated into 10, 50 and 75 µM of EPA or DHA for 24 h, and 100 nM of LPS was added to the culture media for 18 h. Total mRNA was extracted and gene expression examined by microarray analysis using Illumina Human HT-12 expression beadchips (Illumina). Results: Pathway analysis revealed that EPA and DHA regulate genes involved in cell cycle regulation, apoptosis, immune response and inflammation, oxidative stress and cancer pathways in a differential and dose-dependent manner. Conclusions: EPA and DHA appear to exert differential effects on gene expression in THP-1 macrophages. Specific effects of n-3 FAs on gene expression levels are also dose-dependent.

Effect of n-3 fatty acids on the expression of inflammatory genes in THP-1 macrophages.

BACKGROUND: Uncontrolled inflammation participates in the development of inflammatory diseases. Beneficial effects of polyunsaturated fatty acids belonging to the n-3 family such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on inflammation have been reported. The present study investigates the basal effects of EPA, DHA and a mixture EPA + DHA on the expression of 10 genes (AKT1, MAPK, NFKB, TNFA, IL1Β, MCP1, ALOX5, PTGS2, MGST1 and NOS2) related to inflammation in unstimulated cultured THP1 macrophages. Cells were incubated for 24 h with n-3 PUFAs (50 µM and 10 µM EPA, DHA, EPA + DHA). Expression levels of inflammatory genes were analyzed by real-time PCR. RESULTS: 50 µM, 10 µM EPA and 50 µM EPA + DHA decreased the expression of genes involved in the NF-κB pathway (MAPK, AKT1, and NFKB). Treatment with 50 µM, 10 µM EPA, 50 µM DHA and EPA + DHA decreased expression levels of cytokines genes IL1Β and MCP1. TNFA expression was decreased by 50 µM, 10 µM of EPA, DHA and with 50 µM EPA + DHA. Two genes involved in the fatty acid metabolism (PTGS2 and ALOX5) were also modulated by the n-3 FAs. 50 µM of DHA and EPA + DHA inhibited PTGS2 expression when the two concentrations of EPA, 50 µM DHA and EPA + DHA inhibited ALOX5 expression. Finally, the effects of n-3 FAs were studied among genes involved in the oxidative stress. 50 µM of each fatty acid increased MGST1 expression. Both concentration of EPA and 50 µM DHA decreased NOS2 expression. CONCLUSION: EPA seems to be more effective than DHA and EPA + DHA in modulating expression levels of selected inflammatory genes. The concentration of 50 µM was globally more effective than 10 µM.