ABSTRACT: The effects of moderate weight gain in adipose tissue gene expression in metabolically-normal (MNO) and metabolically-abnormal (MAO) subjects
Project description:Obesity is associated with insulin resistance and increased intrahepatic triglyceride (IHTG) content, which are key risk factors for diabetes and cardiovascular disease. However, a subset of obese people does not develop these metabolic complications. We tested the hypothesis that MNO, but not MAO, people are protected from the adverse metabolic effects of weight gain. To this end, global transcriptional profile in adipose tissue before and after weight gain was evaluated by microarray analyses. We collected subcutaneous adipose tissue samples from MNO (n=11) and MAO (n=7) subjects before and after moderate (~6%) weight gain (total 36 samples). We evaluated the effects of weight gain on adipose tissue gene expression in both MNO and MNO subjects.We used the GeneChip Human Gene 1.0 ST array (Affymetrix, Santa Clara, CA, USA).
Project description:Obesity is associated with insulin resistance and increased intrahepatic triglyceride (IHTG) content, which are key risk factors for diabetes and cardiovascular disease. However, a subset of obese people does not develop these metabolic complications. We tested the hypothesis that MNO, but not MAO, people are protected from the adverse metabolic effects of weight gain. To this end, global transcriptional profile in adipose tissue before and after weight gain was evaluated by microarray analyses.
Project description:Obesity gives rise to metabolic complications by mechanisms that are poorly understood. While chronic inflammatory signaling in adipose tissue is typically associated with metabolic deficiencies linked to excessive weight gain, we identified a subset of NRP1-expressing myeloid cells that accumulate in adipose tissue and protect against obesity and metabolic syndrome. Ablation of NRP1 in macrophages compromised lipid uptake in these cells, which reduced substrates for fatty acid β-oxidation and shifted energy metabolism of these macrophages towards a more inflammatory glycolytic metabolism. Conditional deletion of NRP1 in LysM Cre-expressing cells lead to inadequate adipose vascularization, accelerated weight gain and reduced insulin sensitivity even independent of weight gain. Transfer of NRP1+ hematopoietic cells improved glucose homeostasis, resulting in the reversal of a prediabetic phenotype. Our findings suggest a pivotal role for adipose tissue resident NRP1+-expressing macrophages in driving healthy weight gain and maintaining glucose tolerance.
Project description:Even though an individual has normal weight that doesn't necessary mean that individual is healthy. There are some normal weight individuals who are metabolically unhealthy due to excess trunk fat. Using RNA-seq data, we observed gene expression changes in breast tissue of normal weight women with trunk fat.
Project description:Background. Differential gene expression in adipose tissue during diet-induced weight loss followed by a weight stability period is not well characterized. Markers of these processes may provide a deeper understanding of the underlying mechanisms. Objective. To identify differentially expressed genes in human adipose tissue during weight loss and weight maintenance after weight loss. Design. RNA from subcutaneous abdominal adipose tissue from nine obese subjects was obtained and analyzed at baseline, after weight reduction on a low calorie diet (LCD), and after a period of group therapy in order to maintain weight stability. Results. Subjects lost 18.8 + 5.4% of their body weight during the LCD and maintained this weight during group therapy. Insulin sensitivity (HOMA) improved after weight loss with no further improvement during weight maintenance. Cyclin-dependent kinase inhibitor 2B (CDKN2B) and JAZF zinc finger 1 (JAZF1), associated with type 2 diabetes, were downregulated. We could also confirm the downregulation of candidates for obesity and related traits, such as tenomodulin (TNMD) and matrix metallopeptidase 9 (MMP9), with weight loss. The expression of other candidates, such as cell death-inducing DFFA-like effector A (CIDEA) and stearoyl-CoA desaturase (SCD) were upregulated during weight loss but returned to baseline levels during weight maintenance. Conclusion. Genes in the adipose tissue are differentially expressed during weight loss and weight maintenance after weight loss. Genes that show sustained regulation may be of potential interest as markers of the beneficial effects of weight loss whereas others seem to be primarily involved in the process of weight loss itself. Nine participants were prescribed a low calorie diet (LCD) containing 1200 kcal/day for approximately three months (101 ± 26 days). Following the weight reduction phase the participants attended a six month follow-up period (167 ± 37 days). By protocol design, subjects were eligible to enter the study if they had lost at least 10% of their initial body weight during the LCD-period and maintained this weight (+5%) after group therapy. Subcutaneous adipose tissue samples were obtained at three time-points: (i) at baseline, (ii) after weight reduction when subjects were no longer losing weight, and (iii) after the group therapy weight maintenance phase.
Project description:Background. Differential gene expression in adipose tissue during diet-induced weight loss followed by a weight stability period is not well characterized. Markers of these processes may provide a deeper understanding of the underlying mechanisms. Objective. To identify differentially expressed genes in human adipose tissue during weight loss and weight maintenance after weight loss. Design. RNA from subcutaneous abdominal adipose tissue from nine obese subjects was obtained and analyzed at baseline, after weight reduction on a low calorie diet (LCD), and after a period of group therapy in order to maintain weight stability. Results. Subjects lost 18.8 + 5.4% of their body weight during the LCD and maintained this weight during group therapy. Insulin sensitivity (HOMA) improved after weight loss with no further improvement during weight maintenance. Cyclin-dependent kinase inhibitor 2B (CDKN2B) and JAZF zinc finger 1 (JAZF1), associated with type 2 diabetes, were downregulated. We could also confirm the downregulation of candidates for obesity and related traits, such as tenomodulin (TNMD) and matrix metallopeptidase 9 (MMP9), with weight loss. The expression of other candidates, such as cell death-inducing DFFA-like effector A (CIDEA) and stearoyl-CoA desaturase (SCD) were upregulated during weight loss but returned to baseline levels during weight maintenance. Conclusion. Genes in the adipose tissue are differentially expressed during weight loss and weight maintenance after weight loss. Genes that show sustained regulation may be of potential interest as markers of the beneficial effects of weight loss whereas others seem to be primarily involved in the process of weight loss itself.
Project description:People with obesity who do not have the metabolic syndrome or components of the metabolic syndrome have been characterized as having metabolically healthy obesity (MHO). However, the existence of MHO has been questioned because people with MHO are at greater risk of developing diabetes and fatal cardiovascular disease than people who are lean and healthy. A 25 year-old woman with rigorously defined MHO (based on normal oral glucose tolerance, insulin sensitivity (assessed by using the hyperinsulinemic-euglycemic clamp procedure), plasma triglyceride and HDL-cholesterol, intrahepatic triglyceride content and carotid intima-media thickness [CIMT]) was evaluated at baseline (BMI=37.7 kg/m2) and 5 years later, after gaining 30.8 kg (32%) in weight (BMI=49.6 kg/m2). The increase in weight was comprised of an 8.8 kg (20%) increase in FFM, 22.0 kg (42%) increase in total body fat, 8.1 kg (37%) increase in leg fat mass, 57% increase in subcutaneous abdominal fat and a 78% in intra-abdominal fat. Weight gain did not have adverse effects on fasting plasma glucose, oral glucose tolerance, beta-cell function, insulin sensitivity, plasma triglyceride, intrahepatic triglyceride content and CIMT. Adipose tissue expression of genes involved in extracellular matrix formation did not change. Adipose tissue expression of several inflammation-related genes increased by more than 30%, but was not associated with a corresponding increase in plasma cytokine concentrations, with the exception of an increase in plasma IL-6. The present case study demonstrates that some people with obesity are resistant to the adverse cardiometabolic effects of excess adiposity and marked weight gain.
Project description:The purpose of this study was to evaluate the effect of progressive weight loss (5, 10, 15% weight loss) on metabolic function such as multi-organ insulin sensitivity and beta-cell function in obese people. We conducted microarray analysis to determine the effect of progressive weight loss on adipose tissue gene expression profile. We examined subcuntaneous adipose tissue samples obtained from 9 obese subjects before (A) and after 5% (B), 10% (C) and 15% (D) weight loss (total 36 samples).
Project description:Obesity is a heterogeneous conditions comprising obese individuals with metabolic disorders (termed metabolically unhealthy obese; MUO) and obese individuals who are metabolically healthy (termed metabolically healthy obese; MHO). We used microarrays to examine differences in subcutaneous adipose tissue gene expression from lean healthy (LH), metabolically healthy obese (MHO), and metabolically unhealthy obese (MUO) individuals. Subcutaneous adipose tissue samples from the periumbilical region were obtained under local anesthesia and after an overnight fast. 50-100 mg of adipose tissue was homogenized and total RNA was extracted after homogenisation in TRIzol reagent using a tissue homogenizer.