Project description:The molecular background of mitochondrial dysfunction in adipose tissue of morbidly obese individuals and bariatric surgery-induced changes in adipose mitochondrial function remain incompletely understood. To evaluate the mechanisms behind the surgery-induced changes and differences between morbidly obese subjects and nonobese controls, we performed a LC-MS/MS proteomics analysis of abdominal subcutaneous (SAT) and visceral adipose tissue samples (VAT) collected from the bariatric surgery, SAT samples collected 6 months after surgery, and control SAT and VAT samples collected from baseline.
Project description:Transcriptional profiling of subcutaneous adipose tissue before and after 2 years of bariatric surgery. This type of surgery produce a masive weight loss in morbidly obese subjects, and improve the comorbidities associated to obesity. Goal was to determine the effects of bariatric surgery on the gene expression of subcutaneous adipose tissue.
Project description:Background & Aims: Bariatric surgery is associated with improved outcomes in subjects with severe obesity. We aimed to determine the prognostic relevance of liver histology in a large cohort of obese patients undergoing bariatric surgery. Methods: In a single center cohort of 492 subjects undergoing Roux-en-Y gastric bypass bariatric surgery with routine perioperative liver biopsy at Geneva University Hospital between January 1997 to December 2004, clinical and histopathological variables were analyzed for association with overall survival. Survival of the cohort was compared to age- and sex-matched life tables from the Swiss general population and propensity score-matched subjects from the third National Health and Nutrition Examination Survey (NHANES III). A 32-gene signature was evaluated in the liver tissue of 47 non-alcoholic steatohepatitis (NASH) subjects. Results: Median body mass index was 43.6 kg/m2. Twenty-one patients (4.2%) died during a median follow-up of 10.3 years. At baseline liver histology, 12% and 16% of subjects had NASH, and fibrosis, respectively. In multivariable Cox regression, presence of NASH (hazard ratio [HR] 3.4, p=0.0087), age greater than 50 years (HR 2.7, p=0.044), hypertension (HR 3.8, p=0.021), and short-term postoperative complications (HR 2.8, p=0.048) were associated with overall survival. Compared to matched NHANES III subjects, bariatric surgery improved long-term survival (HR 0.54, p=0.035), although this benefit was not observed in the subgroup of NASH patients (HR 0.97, p=0.94). A 32-gene poor prognosis signature prediction was associated with worse overall survival within NASH subjects (n=47, HR = 7.7, p=0.03 ). Conclusions Histologically proven NASH was associated with increased long-term mortality in subjects undergoing bariatric surgery. Although survival benefit of bariatric surgery may be limited in obese patients with NASH, a 32-gene expression signature appears to predict long term mortality in these patients.
Project description:Low-grade chronic inflammation plays an important role in the development of obesity and obesity-associated disorders such as insulin resistance, type 2 diabetes, the metabolic syndrome and atherosclerosis. One possible link between obesity and inflammation is the enhanced activation of circulating monocytes making them more prone to infiltration into the adipose and vascular tissues of obese persons. Furthermore, weight loss after bariatric surgery is associated with less inflammation. Transcriptome analysis of circulating monocytes from control and obese patients before and after bariatric surgery will potentially provide insights into the pathophysiology of obesity and associated disorders and supply biomarkers for diagnostic purpose. The cohort comprised 6 lean age-matched controls (BMI: 20.3±0.5 kg/m2, mean±SEM) and 18 obese individuals without clinical symptoms of cardiovascular disease (BMI: 45.1±1.4 kg/m2, P<0.001 compared with lean controls). These 18 morbidly obese subjects were referred to our hospital for bariatric surgery. Before they were included, individuals were evaluated by an endocrinologist, an abdominal surgeon, a psychologist and a dietician. Only after multidisciplinary deliberation, the selected patients received a laparoscopic Roux-en-Y gastric bypass. CD14+ monocytes were collected before and three months after bariatric surgery (BMI: 37.5±1.3 kg/m2, P<0.001 compared with before weight loss), total RNA was extracted and subjected to genome-wide expression analysis. Samples consisted of CD14+ monocytes from 6 lean controls and 18 morbidly obese patients before and three months after bariatric surgery. The 6 lean controls were also used to make 6 control pools.
Project description:The main objective of this project is to compare the miRNA expression profile of paired visceral adipose tissue and skeletal muscle from obese patients undergoing bariatric surgery. More than 300 miRNAs were identified by Next Generation Sequencing technique in both the visceral adipose tissue and the skeletal muscle of six obese women undergoing bariatric surgery.
Project description:Background: Low-density neutrophils (LDN) are increased in several inflammatory diseases, and may also play a role in low-grade chronic inflammation in obesity. Yet their role in obesity or the effect of bariatric surgery-induced weight loss is unknown. Methods: We compared circulating LDN, their function, and gene expression between morbidly obese patients (MOP; BMI > 40 Kg/m2) and normal-weight controls (NWC; BMI < 25 Kg/m2) in a case-control study. Additionally, in a prospective longitudinal study, we measure changes in the frequency of LDN before and after bariatric surgery, and tested possible associations with metabolic and inflammatory parameters. Findings: LDN and inflammatory markers were significantly increased in MOP (n=27) compared to NWC (n=20). Transcriptome analysis of LDN from MOP showed an increased neutrophil-related gene expression signature associated with inflammation, neutrophil activation, and immunosuppressive function. However, LDN did not suppress T cells proliferation and produced low levels of ROS. Circulating LDN in MOP significantly decreased after surgery in parallel with BMI, metabolic syndrome and inflammatory markers. Interpretation: Obesity increases LDN with inflammatory gene signature. Bariatric surgery has anti-inflammatory effect including reduction of LDN. Gene expression and phenotype suggest that LDN represent a neutrophil subset that may be associated with obesity-associated chronic inflammation that promotes co-morbidities.
Project description:Genome-wide expression profiles in peripheral monocytes (PM) from 19 obese women before and 3 months after bariatric surgery using the RNA-seq technology. This dataset is linked to the dataset GSE65540 providing expression profiles in subcutaneous adipose tissue (SAT) in the same population. Due to exclusion of some individuals for technical reasons, the overlap between the 2 datasets is of 18 women. mRNA sequencing of peripheral monocyte (PM) samples from 19 obese women before and 3 months after bariatric surgery
Project description:Low-grade chronic inflammation plays an important role in the development of obesity and obesity-associated disorders such as insulin resistance, type 2 diabetes, the metabolic syndrome and atherosclerosis. One possible link between obesity and inflammation is the enhanced activation of circulating monocytes making them more prone to infiltration into the adipose and vascular tissues of obese persons. Furthermore, weight loss after bariatric surgery is associated with less inflammation. Transcriptome analysis of circulating monocytes from control and obese patients before and after bariatric surgery will potentially provide insights into the pathophysiology of obesity and associated disorders and supply biomarkers for diagnostic purpose. The cohort comprised 6 lean age-matched controls (BMI: 20.3±0.5 kg/m2, mean±SEM) and 18 obese individuals without clinical symptoms of cardiovascular disease (BMI: 45.1±1.4 kg/m2, P<0.001 compared with lean controls). These 18 morbidly obese subjects were referred to our hospital for bariatric surgery. Before they were included, individuals were evaluated by an endocrinologist, an abdominal surgeon, a psychologist and a dietician. Only after multidisciplinary deliberation, the selected patients received a laparoscopic Roux-en-Y gastric bypass. CD14+ monocytes were collected before and three months after bariatric surgery (BMI: 37.5±1.3 kg/m2, P<0.001 compared with before weight loss), total RNA was extracted and subjected to genome-wide expression analysis.