P088 Metabolomic analysis reveals differences among UC and non-IBD human colonic resections: role of GPCRs
Bauset, C.(1);Carda-Diéguez, M.(2);Buetas, E.(2);Coll, S.(1);Lis-López, L.(1);Seco-Cervera, M.(3);Navarro, F.(4);Mira, Á.(2);Calatayud, S.(1);Barrachina, M.D.(1);Cosín-Roger, J.(3);
(1)Universidad de Valencia, Pharmacology, Valencia, Spain;(2)FISABIO, Genomics and Health Department, Valencia, Spain;(3)FISABIO, Unidad Mixta Facultad de Medicina-Hospital Dr. Peset, Valencia, Spain;(4)Hospital de Manises, Colorectal surgery, Valencia, Spain;
Background
Metabolomics is a recent technique that has bounced into Inflammatory Bowel Diseases (IBD) due to its capacity to elucidate specific metabolites involved in the pathology and changes in the metabolomic profile have been detected in urine, blood or feces from UC patients. G-protein coupled receptors (GPCRs) have been recently identified as promising pharmacological targets. We aim to characterize the metabolomic profile and metabolite-sensing GPCRs expression in colonic resections from UC patients.
Methods
Colonic resections from UC (n=18) and non-IBD (n=20) patients were obtained. Metabolomic analysis was performed using Nuclear Magnetic Resonance (NMR) to study polar metabolites and Gas-Chromatography or Liquid-Chromatography Mass-Spectrometry to study non-polar metabolites.
Results
Results are expressed as μg of metabolite per gram of tissue. Gene expression of GPCRs was analyzed by qPCR. Data were expressed as fold induction vs control (mean±SEM) and compared by a t-test. A p-value<0.05 was considered statistically significant. Pearson correlation matrix were performed with R or mixOmics library in R. Metabolomic analysis revealed in colon of UC patients significant increased levels of propionic acid (7.7±1.1), undecanoic acid (0.3±0.02) decanoic acid (4.5±0.9), myristic acid (64.5±8.7), α-linoleic acid (23.1±4.0), aspartic acid (33.9±3.4), phenylalanine (8.8±1.6), glutamic acid, (136.3±10.8), b-hydroxybutyric (8.3±0.9) acid and lactic acid (297.5±34.7) vs non-IBD patients. Gene expression of GPR43 (22.7±9.5), GPR41 (4.7±1.7), GPR109a (19.1±5.3), GPR109b (13.6±4.6), GPR91 (13.2±5.7), GPR84 (6.7±2.0), GPR40 (6.6±1.8), GPR65 (3.0±0.5) and GPR68 (4.6±1.0) were significantly increased in UC patients compared with controls. In contrast, GPR120 (0.9±0.3), GPR119 (0.6±0.2) and GPR35 (0.5±0.1) were significantly reduced in UC patients. N-oleylethanolamide positively correlates with most of GPCRs, especially GPR68, GPR84 and GPR91 while acetic and succinic acids negatively correlate with GPR4 (Fig.1A). In UC patients, medium-chain fatty acids (FA) and most long-chain FA positively correlate with GPR84, GPR142, GPR43, GPR109a, GPR109b, GPR91 and GPR132 (Fig. 1C).
Fig1. Graphs show the correlations between data relative to mRNA expression of GPCRs (expressed as ΔCt) vs metabolites. (A) Data from controls and UC. (B) Only controls. (C) Only UC.
Conclusion
Increased levels of several metabolites and GPCRs are detected in the colon of UC patients and their correlations suggest potential candidates to be involved in UC pathophysiology.