title: Upregulated TNF Expression 1 Year After Bariatric Surgery Reflects a Cachexia-Like State in Subcutaneous Adipose Tissue.
abstract: Adipose tissue dysfunction contributes to obesity-associated chronic diseases. In the first year after bariatric surgery, obese patients significantly improve their metabolic status upon losing weight. We aimed to investigate whether changes in subcutaneous adipose tissue gene expression reflect a restoration of a healthy lean phenotype after bariatric surgery.
  
  
  
  Thirty-one severely obese patients (BMI ≥ 40 kg/m2) were examined before and after surgery. subcutaneous adipose tissue (SAT) was collected during and 1 year after bariatric surgery. SAT from 20 matched lean and overweight patients (BMI < 30 kg/m2) was collected during elective abdominal surgery. Baseline characteristics and SAT gene expression relevant to glucose and lipid metabolism, inflammation, and apoptosis were analyzed.
  
  
  
  After surgery, mean BMI decreased from 46.1 ± 6.3 to 31.1 ± 5.7 kg/m2and homeostasis model assessment of insulin resistance from 5.4 ± 5.3 to 0.8 ± 0.8. SAT expression of most analyzed inflammatory cytokines, growth factors, and metabolic and cell surface markers was greatly downregulated even compared to the lean cohort. In contrast, gene expression of TNF and CASP3 was significantly upregulated. Elastic net regression analysis showed that fasting glucose levels and CASP3 predicted increased TNF expression in the post-obese group.
  
  
  
  Gene expression patterns in SAT 1 year after bariatric surgery point to a reduced inflammation. The unexpected high TNF expression in SAT of post-obese subjects is most likely not an indicator for inflammation, but rather an indicator for increased lipolysis and adipose tissue catabolism. Notably, after bariatric surgery SAT gene expression reflects a cachexia-like phenotype and differs from the lean state.
authors.affiliation: Christian Doppler Laboratory for Cardio-Metabolic Immunotherapy and Clinical Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Waehringer Guertel, 18-201090, Vienna, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Jürets
authors.affiliation: Christian Doppler Laboratory for Cardio-Metabolic Immunotherapy and Clinical Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Waehringer Guertel, 18-201090, Vienna, Austria.
authors.forename: Bianca Karla
authors.initials: BK
authors.lastname: Itariu
authors.affiliation: Christian Doppler Laboratory for Cardio-Metabolic Immunotherapy and Clinical Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Waehringer Guertel, 18-201090, Vienna, Austria.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Keindl
authors.affiliation: Department of Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Prager
authors.affiliation: Department of Surgery, Medical University of Vienna, Vienna, Austria.
authors.forename: Felix
authors.initials: F
authors.lastname: Langer
authors.affiliation: Department of Surgery, Göttlicher Heiland Hospital, Vienna, Austria.
authors.forename: Viktor
authors.initials: V
authors.lastname: Grablowitz
authors.affiliation: Christian Doppler Laboratory for Cardio-Metabolic Immunotherapy and Clinical Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Waehringer Guertel, 18-201090, Vienna, Austria.|Department of Pediatrics and Adolescent Medicine, Clinical Division of Pediatric Pulmonology, Allergology and Endocrinology, Medical University of Vienna, Vienna, Austria.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Zeyda
authors.affiliation: Christian Doppler Laboratory for Cardio-Metabolic Immunotherapy and Clinical Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Waehringer Guertel, 18-201090, Vienna, Austria. thomas.stulnig@meduniwien.ac.at.
authors.forename: Thomas Michael
authors.initials: TM
authors.lastname: Stulnig
mesh_terms: D000328:Adult; D050110:Bariatric Surgery; D002100:Cachexia / Q000235:genetics*; D053148:Caspase 3 / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D006801:Humans; D050356:Lipid Metabolism; D008297:Male; D009767:Obesity, Morbid / Q000378:metabolism / Q000601:surgery*; D050151:Subcutaneous Fat / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D014409:Tumor Necrosis Factor-alpha; C505407:CASP3 protein, human; D053148:Caspase 3
keywords: Bariatric surgery; Gene expression; Subcutaneous adipose tissue; Tumor necrosis factor; Weight loss