Mechanisms of weight maintenance under high- and low-protein, low-glycaemic index diets

SCOPE: Weight maintenance after intended weight loss is a challenge in an obesogenic environment. In a large multicentre dietary intervention study (DiOGenes), it has recently been demonstrated that a high-protein/low-glycaemic index (HP/LGI) diet was slightly more efficient in maintaining weight loss than low-protein/LGI or high-GI (LP/LGI or HGI) diets. Here, we use a proteomic approach to assess the molecular mechanisms behind this positive effect. METHODS AND RESULTS: A subset of the most successful (weight loser, n=12) and unsuccessful (weight re-gainer, n=12) individuals consuming the LGI diets with either high- or low-protein content (HP or LP/LGI), following an initial calorie deficit run-in weight loss phase, were analyzed at the plasma protein level. Proteomic analysis revealed 18 proteins regulated after 6 months of the dietary weight maintenance phase. Furthermore, 12 proteins were significantly regulated as a function of success rate under an HP diet, arising as candidate biomarkers of mechanisms of successful weight maintenance under an HP/LGI diet. Pregnancy-zone protein (PZP) and protein S (PROS1) were revealed as novel biomarkers of weight maintenance showing opposite effects. CONCLUSION: Semantic network analysis of the 12 regulated proteins revealed that under an HP/LGI an anti-atherogenic effect and alterations of fat metabolism were associated with the success of maintaining the initial weight loss

Transcriptome and translational signaling following endurance exercise in trained skeletal muscle: impact of dietary protein

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Redox Chemistry and Electronic Properties of 2,3,5,6-Tetrakis(2-pyridyl)pyrazine-Bridged Diruthenium Complexes Controlled by N,C,N '-BisCyclometalated Ligands

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Contribution of mesothelial cells in the expression of inflammatory-related factors in omental adipose tissue of obese subjects.

OBJECTIVE: The objective of this study was to determine the contribution of mesothelial cells, present in human omental adipose tissue (OAT) but not in the subcutaneous depot (SAT), on the expression of inflammation-related factors. DESIGN: Comparison of the expression profiles of inflammation-related genes in mesothelial cells with those in the adipocyte-enriched (AEF) and stromal vascular fractions (SVF) and localization of interleukin-18 (IL-18) expression in adipose depots. SUBJECTS: Eleven obese Caucasian female subjects undergoing gastric bypass surgery (body mass index: 43.6+/-1.3 kg/m(2); age: 41.6+/-2.3 years). MEASUREMENTS: The expression profiles of cytokine and chemokine-related genes in mesothelial cells and in cell fractions prepared from OAT were assessed by the microarray technique. The differential expression of IL-18 was confirmed by real-time PCR and the protein was localized in adipose depots by immunohistochemistry. RESULTS: Microarray data analysis demonstrated that, of the 16 cytokine and chemokine-related genes that were upregulated in mesothelial cells compared with the AEF, IL-18 was the cytokine with the highest differential expression. IL-18 expression was similar in mesothelial cells and the SVF. In both SAT and OAT, IL-18 was immunolocalized in neutrophils and mast cells, but not in macrophages nor adipocytes. This cytokine was also detected in mesothelial cells in OAT. This additional source of expression may explain the higher IL-18 expression levels in OAT than SAT (+5.9-fold). CONCLUSION: By their capacity to express inflammatory-related factors, and in particular the proinflammatory cytokine IL-18 in OAT, mesothelial cells appear as a new player in the process of low-grade inflammation associated with obesity