Project description:Mesenchymal stem/stromal cells (MSCs) were harvested from subcutaneous adipose tissue of patients with obesity or healthy controls and expanded for 3-4 passages, and 5hmC profiles were examined through hydroxymethylated DNA immunoprecipitation sequencing (hMeDIP-seq). We hypothesized that obesity and cardiovascular risk factors induce functionally-relevant, locus-specific changes in overall exonic coverage of 5hmC in human adipose-derived MSCs.
Project description:Genome wide DNA methylation in blood, subcutaneous and omental visceral adipose tissue from two-step surgical approach (N=9) was analysed in patients with severe obesity using Illumina 850K EPIC technology before and after metabolic surgery (Leipzig Obesity BioBank (LOBB) cohort). Additionally, a validation blood cohort of patients with obesity undergoing metabolic surgery was analyzed for results validation.
Project description:Our study seeked to identify changes in DNA methylation and gene expression that might underlie type 2 diabetes susceptibility. We investigated DNA methylation and gene expression in VAT biopsies from 19 women with obesity, without (n=9) or with T2D (n=10). We analyzed and compared the methylome and transcriptome of visceral adipose tissue biopsies of women with obesity, with and without type 2 diabetes. Differential methylation and expression where then paired to test for Pearson's correlation to measure their relationship.
Project description:Visceral adipose tissue samples were obtained from severely obese individuals that underwent bariatric surgery. The goal of this study was to identify tissue specific methylation QTLs. Whole-transcriptome subcutaneous adipose tissue methylation levels were determined in 71 individuals with a BMI >35 kg/m2. Bisulphite converted DNA from the 71 visceral adipose tissue samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip.
Project description:Metabolic plasticity is the ability of a biological system to adapt its metabolic phenotype to different environmental stressors. We used a whole-body and tissue- specific phenotypic, functional, metabolomic and transcriptomic approach to systematically assess metabolic plasticity in diet-induced obese mice after a combined nutritional and exercise intervention. Although most pathological features were successfully reverted, we observed a high degree of metabolic dysfunction irreversibility in visceral white adipose tissue, characterised by abnormal mitochondrial morphology and functionality. Despite two sequential therapeutic interventions and apparent global phenotypic recovery, obesity specifically triggered in visceral adipose tissue a cascade of events progressing from mitochondrial metabolic and proteostatic defects to widespread cellular stress, which compromises its biosynthetic and recycling capacity. Our data indicate that obesity prompts a lasting metabolic fingerprint that leads to an aging-like progressive breakdown of metabolic plasticity in white adipose tissue. A similar phenomenon was observed in an obese human cohort following weight loss. Further human studies should help dissect patients’ stratification of this significant milestone in obesity progression.
Project description:Vascular dysfunction and chronic inflammation are characteristics of obesity-induced adipose tissue dysfunction. Proinflammatory cytokines can drive an endothelial-to-mesenchymal transition (EndoMT), where endothelial cells undergo a phenotypic switch to mesenchymal-like cells that are pro-inflammatory and pro-fibrotic. In this study, we sought to determine whether obesity can promote EndoMT in adipose tissue. Mice in which endothelial cells are lineage-traced with eYFP were fed a high-fat/high-sucrose (HF/HS) or Control diet for 13, 26, and 52 weeks, and EndoMT was assessed in adipose tissue depots as percentage of CD45-CD31-Acta2+ mesenchymal-like cells that were eYFP+. EndoMT was also assessed in human adipose endothelial cells through cell culture assays and by the analysis of single cell RNA sequencing datasets obtained from the visceral adipose tissues of obese individuals. Quantification by flow cytometry showed that mice fed a HF/HS diet display a time-dependent increase in EndoMT over Control diet in subcutaneous adipose tissue (+3.0%, +2.6-fold at 13 weeks; +10.6%, +3.2-fold at 26 weeks; +11.8%, +2.9-fold at 52 weeks) and visceral adipose tissue (+5.5%, +2.3-fold at 13 weeks; +20.7%, +4.3-fold at 26 weeks; +25.7%, +4.8-fold at 52 weeks). Transcriptomic analysis revealed that EndoMT cells in visceral adipose tissue have enriched expression of genes associated with inflammatory and TGFb signaling pathways. Human adipose-derived microvascular endothelial cells cultured with TGF-β1, IFN-γ, and TNF-⍺ exhibited a similar upregulation of EndoMT markers and induction of inflammatory response pathways. Analysis of single cell RNA sequencing datasets from visceral adipose tissue of obese patients revealed a nascent EndoMT sub-cluster of endothelial cells with reduced PECAM1 and increased ACTA2 expression, which was also enriched for inflammatory signaling genes and other genes associated with EndoMT. These experimental and clinical findings show that chronic obesity can accelerate EndoMT in adipose tissue. We speculate that EndoMT is a feature of adipose tissue dysfunction that contributes to local inflammation and the systemic metabolic effects of obesity.