Project description:Alterations in intestinal microbiota and intestinal short chain fatty acids profiles have been associated with the pathophysiology of obesity and insulin resistance. Whether intestinal microbiota dysbiosis is a causative factor in humans remains to be clarified We examined the effect of fecal microbial infusion from lean donors on the intestinal microbiota composition, glucose metabolism and small intestinal gene expression. Male subjects with metabolic syndrome underwent bowel lavage and were randomised to allogenic (from male lean donors with BMI<23 kg/m2, n=9) or autologous (reinfusion of own feces, n=9) fecal microbial transplant. Insulin sensitivity and fecal short chain fatty acid harvest were measured at baseline and 6 weeks after infusion. Intestinal microbiota composition was determined in fecal samples and jejunal mucosal biopsies were also analyzed for the host transcriptional response. Insulin sensitivity significantly improved six weeks after allogenic fecal microbial infusion (median Rd: from 26.2 to 45.3 μmol/kg.min, p<0.05). Allogenic fecal microbial infusion increased the overall amount of intestinal butyrate producing microbiota and enhanced fecal harvest of butyrate. Moreover, the transcriptome analysis of jejunal mucosal samples revealed an increased expression of genes involved in a G-protein receptor signalling cascade and subsequently in glucose homeostasis. Lean donor microbial infusion improves insulin sensitivity and levels of butyrate-producing and other intestinal microbiota in subjects with the metabolic syndrome. We propose a model wherein these bacteria provide an attractive therapeutic target for insulin resistance in humans. (Netherlands Trial Register NTR1776).
Project description:Insulin resistance, the defective regulation of glucose metabolism by insulin, increases the risk of type 2 diabetes and cardiovascular disease. It is not yet known how insulin resistance remodels signalling networks in human tissues. Here, we define the signalling architecture of insulin resistance in skeletal muscle. We measured phenotypes and phosphoproteomes of insulin resistant and insulin sensitive subjects as they responded to exercise and an insulin infusion, quantifying more than 26,000 phosphosites in 114 skeletal muscle biopsies. Incorporating a temporal component to personalised phosphoproteomics identified signalling linked with the range of insulin sensitivity across the participants.
2024-11-22 | PXD032948 | Pride
Project description:Effect of fecal microbiota transplantation combined with Mediterranean diet on insulin sensitivity in subjects with metabolic syndrome
Project description:We investigated the effect of a saturated (SFA) and a monounsaturated (MUFA) rich diet on insulin sensitivity and adipose tissue gene expression profiles of subjects at risk for metabolic syndrome. A controlled-feeding trial was performed with 20 moderately overweight subjects. Subjects received a SFA-rich or a MUFA-rich diet for 8 weeks. Subcutaneous adipose tissue samples were obtained and insulin sensitivity was measured. Whole genome micro-array analysis was performed on the adipose tissue samples. Consumption of a SFA-rich diet resulted in a pro-inflammatory 'obese-like' gene expression profile while consumption of a MUFA-rich diet caused a more anti-inflammatory profile. This suggests that replacement of dietary SFA by MUFA could prevent adipose tissue inflammation and may reduce the risk for inflammation related diseases such as the metabolic syndrome.
Project description:Context: It is not known whether biological differences reported between subcutaneous (SAT) and visceral (VAT) adipose tissue depots underlie the pathogenicity of visceral fat. Objective: We compared SAT and VAT gene expression according to obesity, visceral fat accumulation, insulin resistance and presence of the metabolic syndrome. Design: Subjects were assigned into 4 groups (lean, overweight, obese and obese with metabolic syndrome). Setting: Subjects were recruited at a university hospital. Patients: 32 women were included. Main Outcome Measures: Anthropometric measurements, euglycemic hyperinsulinemic clamps, blood analyses and computed tomography scans were performed and paired samples of SAT and VAT were obtained for DNA microarray-based gene expression profiling.
Project description:The accumulation of intramyocellular lipid (IMCL) is recognized as an important determinant of insulin resistance, and is increased by a high-fat diet (HFD). However, the effects of HFD on IMCL and insulin sensitivity are highly variable. We used microarrays to detail to identify the genes in skeletal muscle that are related to inter-individual variation of the effects with HFD on the accumulation of intramyocellular lipid and insulin sensitivity. In order to identify the gene expression profile related with inter-individual variation of the effects with high fat diet on the accumulation of intramyocellular lipid and insulin sensitivity, we classified subjects who showed a large increase in intramyocellular lipid and a large decrease in glucose infusion rate by high fat diet as the high-responder (HR), and the subjects who showed a small increase in intramyocellular lipid and a small decrease in glucose infusion rate were classified as the low-responder (LR). In 5 subjects in each group, skeletal muscle sample selected at before (pre) and after (post) 3days high fat diet for RNA extraction and hybridization on Affymetrix microarrays.
Project description:We investigated the effect of a saturated (SFA) and a monounsaturated (MUFA) rich diet on insulin sensitivity and adipose tissue gene expression profiles of subjects at risk for metabolic syndrome. A controlled-feeding trial was performed with 20 moderately overweight subjects. Subjects received a SFA-rich or a MUFA-rich diet for 8 weeks. Subcutaneous adipose tissue samples were obtained and insulin sensitivity was measured. Whole genome micro-array analysis was performed on the adipose tissue samples. Consumption of a SFA-rich diet resulted in a pro-inflammatory 'obese-like' gene expression profile while consumption of a MUFA-rich diet caused a more anti-inflammatory profile. This suggests that replacement of dietary SFA by MUFA could prevent adipose tissue inflammation and may reduce the risk for inflammation related diseases such as the metabolic syndrome. In a parallel controlled feeding trial, subcutaneous adipose tissue samples were collected from moderately overweight human subjects at baseline and after 8 weeks consumption of either SFA-rich or MUFA-rich diets. RNA was isolated from the samples using Trizol and the Qiagen RNeasy Micro kit (Qiagen, Venlo, the Netherlands). RNA was was labeled using a one-cycle cDNA labeling kit (MessageAmpTM II-Biotin Enhanced Kit, Ambion, Inc.) and hybridized to Affymetrix NuGO_Hs1a52018 arrays.
Project description:The study aimed to investigate molecular signatures in peripheral blood of individuals affected by metabolic syndrome (MetS) and different degrees of obesity. Metabolic health of 1204 individuals was assessed, and 32 subjects were recruited to four study groups: MetS lean, MetS obese, “healthy obese” and healthy lean. Whole-blood transcriptome next generation sequencing with functional data analysis was carried out.
Project description:Background and Aims: Insulin resistance is a key factor in the pathogenesis of NAFLD. We evaluated the importance of subcutaneous abdominal adipose tissue (SAAT) inflammation and both plasma and SAAT-derived exosomes in regulating insulin sensitivity in people with obesity and NAFLD. Methods: Adipose tissue inflammation (macrophage and T cell content and gene expression of proinflammatory cytokines), liver and whole-body insulin sensitivity (assessed by a hyperinsulinemic-euglycemic clamp and glucose tracer infusion), and 24-hour serial plasma cytokine concentrations were evaluated in three groups stratified by adiposity, insulin sensitivity and intrahepatic triglyceride (IHTG) content: 1) metabolically-healthy lean (LEAN; n=14); 2) metabolically-healthy obese with normal IHTG content (OB-NL; n=28); and 3) metabolically-unhealthy obese with NAFLD (OB-NAFLD; n=28). The effect of plasma and SAAT-derived exosomes on insulin action (insulin-stimulated Akt phosphorylation) in human skeletal muscle myotubes was assessed in a subset of participants. Results: Proinflammatory macrophages, proinflammatory CD4 and CD8 T cell populations, and gene expression of several cytokines in SAAT were greater in the OB-NAFLD than the OB-NL and LEAN groups. However, with the exception of PAI-1, which was greater in the OB-NAFLD than the LEAN and OB-NL groups, 24-hour plasma cytokine concentration areas-under-the-curve (AUC) were not different between groups. The percentage of proinflammatory macrophages and plasma PAI-1 concentration AUC were inversely correlated with both hepatic and whole-body insulin sensitivity. Compared with exosomes from OB-NL participants, plasma and SAAT-derived exosomes obtained from the OB-NAFLD group impaired insulin action in myotubes. Conclusion: These results suggest SAAT-derived exosomes and PAI-1 are involved in the pathogenesis of systemic insulin resistance in people with obesity and NAFLD. ClinicalTrials.gov number: NCT02706262.
Project description:Purpose. Insulin resistant muscle is resistant to gene expression changes induced by acute exercise. This study was undertaken to identify transcription factors that differentially respond to exercise in insulin resistance. Candidate transcription factors were identified from analysis of 5’-untranslated regions (5’-UTRs) of exercise responsive genes and from analysis of the 5’-UTRs of genes coding for proteins that differ in abundance in insulin resistance. Research design and methods. Muscle biopsies were obtained from lean and obese subjects before and after a single exercise bout. Euglycemic glucose clamps assessed insulin sensitivity. Global proteomics analysis identified differentially abundant proteins. The 5’-UTRs of genes coding for significant proteins were subjected to transcription factor enrichment analysis to identify candidate transcription factors. Q-rt-PCR to determine expression of candidate transcription factors was performed on RNA from resting and post-exercise muscle biopsies; immunoblots quantified protein abundance. Results. Obese subjects were insulin resistant compared to lean but performed exercise at the same intensity. Proteins involved in mitochondrial function, protein targeting and translation, and metabolism were among those significantly different between the groups. Transcription factor enrichment analysis of genes coding for these proteins revealed new candidate transcription factors. Q-rt-PCR analysis of RNA and immunoblot analysis from pre- and post-exercise muscle biopsies revealed several transcription and growth factors that had altered responses to exercise in insulin resistant subjects. Conclusions. These results confirm findings of an association between insulin sensitivity and transcription factor mRNA response to exercise and extend these results to show that obesity also may be a sufficient prerequisite for exercise resistance. Analysis of the muscle proteome together with determination of effects of exercise on expression of transcription factors suggests that abnormal responses of transcription factors to exercise may be responsible for differences in protein abundances in insulin resistant muscle.