Molecular phenomics of a high-calorie diet-induced porcine model of prepubertal obesity.

As obesity incidence is alarmingly rising among young individuals, we aimed to characterize an experimental model of this situation, considering the similarity between human and porcine physiology. For this reason, we fed prepubertal (63 days old) Duroc breed females (n=21) either with a standard growth diet (3800 kcal/day) or one with a high-calorie content (5200 kcal/day) during 70 days. Computerized tomography, mass-spectrometry-based metabolomics and lipidomics, as well as peripheral blood mononuclear cell transcriptomics, were applied to define traits linked to high-calorie intake. Samples from a human cohort confirmed potential lipidomic markers. Compared to those fed a standard growth diet, pigs fed a high-calorie diet showed an increased weight gain (13%), much higher adiposity (53%), hypertriacylglyceridemia and hypercholesterolemia in parallel to insulin resistance. This diet induced marked changes in the circulating lipidome, particularly in phosphatidylethanolamine-type molecules. Also, circulating specific diacylglycerol and monoacylglycerol contents correlated with visceral fat and intrahepatic triacylglycerol concentrations. Specific lipids associated with obesity in swine (mainly belonging to glycerophospholipid, triacylglyceride and sterol classes) were also linked with obesity traits in the human cohort, reinforcing the usefulness of the chosen approach. Interestingly, no overt inflammation in plasma or adipose tissue was evident in this model. The presented model is useful as a preclinical surrogate of prepubertal obesity in order to ascertain the pathophysiology interactions between energy intake and obesity development.

Adipose Tissue Protein Glycoxidation is Associated with Weight-Loss Potential.

OBJECTIVE: This study aimed to characterize the differences in protein oxidation biomarkers in adipose tissue (AT) as an indicator of AT metabolism and bariatric surgery weight-loss success. METHODS: A human model, in which sixty-five individuals with obesity underwent bariatric surgery, and a diet-induced obesity animal model, in which animals were treated for 2 months with normocaloric diets, were analyzed to determine the associations between AT protein oxidation and body weight loss. Protein oxidative biomarkers were determined by gas chromatography/mass spectrometry in AT from human volunteers before the surgery, as well as 2 months after a diet treatment in the animal model. RESULTS: The levels of carboxyethyl-lysine (CEL) and 2-succinocystein (2SC) in both visceral and subcutaneous AT before the surgery directly correlated with greater weight loss in both human and animal models. 2SC levels in subcutaneous AT greater than 4.7 × 106  µmol/mol lysine (95% CI: 3.4 × 106 to 6.0 × 106 ) may predict greater weight loss after bariatric surgery (receiver operating characteristic curve area = 0.8222; P = 0.0047). Additionally, it was observed that individuals with diabetes presented lower levels of CEL and 2SC in subcutaneous AT (P = 0.0266 and P = 0.0316, respectively) compared with individuals without diabetes. CONCLUSIONS: CEL and 2SC in AT are useful biomarkers of AT metabolism and predict the individual's ability to reduce body weight after bariatric surgery.