Dataset Information

The short-term and long-term effects of bariatric/metabolic surgery on subcutaneous adipose tissue inflammation in humans.

ABSTRACT: CONTEXT:The mechanisms mediating the short- and long-term improvements in glucose homeostasis following bariatric/metabolic surgery remain incompletely understood. OBJECTIVE:To investigate whether a reduction in adipose tissue inflammation plays a role in the metabolic improvements seen after bariatric/metabolic surgery, both in the short-term and longer-term. DESIGN:Fasting blood and subcutaneous abdominal adipose tissue were obtained before (n=14), at one month (n=9), and 6-12months (n=14) after bariatric/metabolic surgery from individuals with obesity who were not on insulin or anti-diabetes medication. Adipose tissue inflammation was assessed by a combination of whole-tissue gene expression and flow cytometry-based quantification of tissue leukocytes. RESULTS:One month after surgery, body weight was reduced by 13.5±4.4kg (p<0.001), with improvements in glucose tolerance reflected by a decrease in area-under-the-curve (AUC) glucose in 3-h oral glucose tolerance tests (-105±98mmol/L * min; p=0.009) and enhanced pancreatic ?-cell function (insulinogenic index: +0.8±0.9pmol/mmol; p=0.032), but no change in estimated insulin sensitivity (Matsuda insulin sensitivity index [ISI]; p=0.720). Furthermore, although biomarkers of systemic inflammation and pro-inflammatory gene expression in adipose tissue remained unchanged, the number of neutrophils increased in adipose tissue 15-20 fold (p<0.001), with less substantial increases in other leukocyte populations. By the 6-12month follow-up visit, body weight was reduced by 34.8±10.8kg (p<0.001) relative to baseline, and glucose tolerance was further improved (AUC glucose -276±229; p<0.001) along with estimated insulin sensitivity (Matsuda ISI: +4.6±3.2; p<0.001). In addition, improvements in systemic inflammation were reflected by reductions in circulating C-reactive protein (CRP; -2.0±5.3mg/dL; p=0.002), and increased serum adiponectin (+1358±1406pg/mL; p=0.003). However, leukocyte infiltration of adipose tissue remained elevated relative to baseline, with pro-inflammatory cytokine mRNA expression unchanged, while adiponectin mRNA expression trended downward (p=0.069). CONCLUSION:Both the short- and longer-term metabolic improvements following bariatric/metabolic surgery occur without significant reductions in measures of adipose tissue inflammation, as assessed by measuring the expression of genes encoding key mediators of inflammation and by flow cytometric immunophenotyping and quantification of adipose tissue leukocytes.

SUBMITTER: Hagman DK

PROVIDER: S-EPMC5407411 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature

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The short-term and long-term effects of bariatric/metabolic surgery on subcutaneous adipose tissue inflammation in humans.

Hagman Derek K DK Larson Ilona I Kuzma Jessica N JN Cromer Gail G Makar Karen K Rubinow Katya B KB Foster-Schubert Karen E KE van Yserloo Brian B Billing Peter S PS Landerholm Robert W RW Crouthamel Matthew M Flum David R DR Cummings David E DE Kratz Mario M

Metabolism: clinical and experimental 20170202

<h4>Context</h4>The mechanisms mediating the short- and long-term improvements in glucose homeostasis following bariatric/metabolic surgery remain incompletely understood.<h4>Objective</h4>To investigate whether a reduction in adipose tissue inflammation plays a role in the metabolic improvements seen after bariatric/metabolic surgery, both in the short-term and longer-term.<h4>Design</h4>Fasting blood and subcutaneous abdominal adipose tissue were obtained before (n=14), at one month (n=9), and ...[more]

PMID: 28403936

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Project description:BackgroundBariatric surgery, especially Roux-en-Y gastric bypass (RYGB), is the most effective and durable treatment option for severe obesity. The mechanisms involving adipose tissue may be important to explain the effects of surgery.MethodsWe aimed to identify the genetic signatures of adipose tissue in patients undergoing RYGB. We evaluated 13 obese, non-diabetic patients (mean age 37 years, 100% women, Body mass index (BMI) 42.2 kg/m2) one day before surgery, 3 and 6 months (M) after RYGB.ResultsAnalysis of gene expression in adipose tissue collected at surgery compared with samples collected at 3 M and 6 M Post-RYGB showed that interleukins [Interleukin 6, Tumor necrosis factor-α (TNF-α), and Monocyte chemoattractant protein-1(MCP1)] and endoplasmic reticulum stress (ERS) genes [Eukaryotic translation initiation factor 2 alpha kinase 3 (EIF2AK3) and Calreticulin (CALR)] decreased during the follow-up (P ≤ 0.01 for all). Otherwise, genes involved in energy homeostasis [Adiponectin and AMP-activated protein kinase (AMPK)], cellular response to oxidative stress [Sirtuin 1, Sirtuin 3, and Nuclear factor erythroid 2-related factor 2 (NRF2)], mitochondrial biogenesis [Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α)] and amino acids metabolism [General control nonderepressible 2 (GCN2)] increased from baseline to all other time points evaluated (P ≤ 0.01 for all). Also, expression of Peroxisome proliferator-activated receptor gamma (PPARϒ) (adipogenesis regulation) was significantly decreased after RYGB (P < 0.05). Additionally, we observed that PGC1α, SIRT1 and AMPK strongly correlated to BMI at 3 M (P ≤ 0.01 for all), as well as ADIPOQ and SIRT1 to BMI at 6 M (P ≤ 0.01 for all).ConclusionsOur findings demonstrate that weight loss is associated with amelioration of inflammation and ERS and increased protection against oxidative stress in adipose tissue. These observations are strongly correlated with a decrease in BMI and essential genes that control cellular energy homeostasis, suggesting an adaptive process on a gene expression level during the caloric restriction and weight loss period after RYGB. Trial registration CAAE: 73,585,317.0.0000.5440.

Project description:Bariatric surgery is an approved treatment for obesity that consistently improves metabolic syndrome, with well-documented beneficial effects on dyslipidemia, cardiovascular risk, nonalcoholic fatty liver disease and glucose homeostasis. In this study, we determined the differential expression genes in three periods after bariatric surgery: short-term (4-months), medium-term (1- and 2-years), and long-term (5-years) periods. Two microarray profiles were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified by comparing the expression of adipose tissue genes before surgery compared to short, medium and long-term periods following surgery. Shared DEGs for the medium-term were evaluated by comparing the DEGs for both 1 and 2 years. 165, 65, and 59 DEGs were identified in short-medium-long periods. The protein-protein interactions were analyzed by STRING. A co-expression network was constructed by mapping the DEGs onto the GeneMANIA plugin of Cytoscape. Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) and wikipathway analysis were done for each group of DEGs. Interleukin-8 receptor activity, complement receptor activity and opsonin receptor activity/N-formyl peptide receptor activity in GO Function enrichment and cellular response to interleukin-8, positive regulation of hippocampal neuron apoptotic process, and positive regulation of hippocampal neuron apoptotic process in GO Process showed the best scores in short-, medium-, and long-term periods, respectively. Eight genes, including CCL2 (Chemokine ligand 2), CXCR4 (CXC motif chemokine receptor 4), EGR2 (Early Growth Response 2), FPR1 (Formyl Peptide Receptor 1), IL6 (interleukin-6), RGS2 (regulator of gene protein signaling2), SELPLG (Selectin P Ligand), and THBS1 (Thrombospondin 1) were identified as shared DEGs in the three periods after surgery. Importantly, results of DAVID database analysis showed 7, 6, 4, and 4 of these genes have roles in immune/ cancer/cardiovascular diseases, type 2 diabetes, myocardial infarct, and atherosclerosis, respectively.

Project description:Bariatric surgery is currently one of the most effective treatments for obesity and leads to significant weight reduction, improved cardiovascular risk factors and overall survival in treated patients. To date, most studies focused on short-term effects of bariatric surgery on the metabolic profile and found high variation in the individual responses to surgery. The aim of this study was to identify relevant metabolic changes not only shortly after bariatric surgery (Roux-en-Y gastric bypass) but also up to one year after the intervention by using untargeted metabolomics. 132 serum samples taken from 44 patients before surgery, after hospital discharge (1-3 weeks after surgery) and at a 1-year follow-up during a prospective study (NCT01271062) performed at two study centers (Austria and Switzerland). The samples included 24 patients with type 2 diabetes at baseline, thereof 9 with diabetes remission after one year. The samples were analyzed by using liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS, HILIC-QExactive). Raw data was processed with XCMS and drift-corrected through quantile regression based on quality controls. 177 relevant metabolic features were selected through Random Forests and univariate testing and 36 metabolites were identified. Identified metabolites included trimethylamine-N-oxide, alanine, phenylalanine and indoxyl-sulfate which are known markers for cardiovascular risk. In addition we found a significant decrease in alanine after one year in the group of patients with diabetes remission relative to non-remission. Our analysis highlights the importance of assessing multiple points in time in subjects undergoing bariatric surgery to enable the identification of biomarkers for treatment response, cardiovascular benefit and diabetes remission. Key-findings include different trend pattern over time for various metabolites and demonstrated that short term changes should not necessarily be used to identify important long term effects of bariatric surgery.

Dataset Information

The short-term and long-term effects of bariatric/metabolic surgery on subcutaneous adipose tissue inflammation in humans.

Publications

The short-term and long-term effects of bariatric/metabolic surgery on subcutaneous adipose tissue inflammation in humans.

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