title: Differential effects of Roux-en-Y gastric bypass surgery on brown and beige adipose tissue thermogenesis.
abstract: BACKGROUND
  There are numerous reports of increased energy expenditure after Roux-en-Y gastric bypass (RYGB) surgery in humans and rodent models but the underlying mechanisms remain poorly understood. In the present study we assessed at the gene expression level whether RYGB leads to recruitment of brown adipose tissue (BAT) and/or beige adipose tissue (BeAT) as a means of enhanced facultative thermogenesis and increased energy expenditure after surgery.
  
  
  METHODS
  Diet-induced obese male Wistar rats were randomized into RYGB-operated (n=10), sham-operated ad libitum fed (Sham) (n=7) or sham-operated body weight matched (BWM) to RYGB groups (n=7). At a stage of postoperatively stabilized weight reduction, BAT (interscapular), subcutaneous (inguinal) and visceral (epididymal and perirenal) white adipose tissue (WAT) depots were collected in the fasted state. Expression of thermoregulatory genes (UCP1, CIDEA and PRDM16) in BAT and WAT as well as specific markers of BeAT (Ear2 and TMEM26) in WAT was analyzed using RT-qPCR.
  
  
  RESULTS
  Compared to Sham rats, UCP1 mRNA expression in BAT was significantly reduced in BWM, but not in RYGB rats. No differences in mRNA expression were found for thermoregulatory proteins or for markers of BeAT in subcutaneous or visceral WAT depots between RYGB and Sham groups.
  
  
  CONCLUSIONS
  The compensatory decrease in BAT thermogenic gene expression typically associated with body weight loss is attenuated after RYGB which, as opposed to recruitment of BeAT, may contribute to overall increases in energy expenditure and weight loss maintenance after surgery.
authors.affiliation: Integrated Research and Treatment Centre for Adiposity Diseases, Department of Medicine, University of Leipzig, Leipzig, Germany.
authors.forename: Mohammed K
authors.initials: MK
authors.lastname: Hankir
authors.affiliation: Integrated Research and Treatment Centre for Adiposity Diseases, Department of Medicine, University of Leipzig, Leipzig, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Bronisch
authors.affiliation: Integrated Research and Treatment Centre for Adiposity Diseases, Department of Medicine, University of Leipzig, Leipzig, Germany.
authors.forename: Constantin
authors.initials: C
authors.lastname: Hintschich
authors.affiliation: Rudolf Boehm Institute of Pharmacology and Toxicology, Department of Medicine, University of Leipzig, Leipzig, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Krügel
authors.affiliation: Department of General, Visceral, Vascular Pediatric Surgery, University of Würzburg, Würzburg, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Seyfried
authors.affiliation: Integrated Research and Treatment Centre for Adiposity Diseases, Department of Medicine, University of Leipzig, Leipzig, Germany. Electronic address: wiebkekristin.fenske@medizin.uni-leipzig.de.
authors.forename: Wiebke K
authors.initials: WK
authors.lastname: Fenske
mesh_terms: D002001:Adipose Tissue, Brown / Q000378:metabolism*; D052436:Adipose Tissue, White / Q000378:metabolism*; D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism; D001835:Body Weight; D004435:Eating; D064429:Fatty Acid Synthases / Q000235:genetics / Q000378:metabolism; D015390:Gastric Bypass; D005786:Gene Expression Regulation; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D022722:Thermogenesis / Q000235:genetics / Q000502:physiology*; D000071256:Uncoupling Protein 1
chemical_list: D051017:Apoptosis Regulatory Proteins; C542951:CIDEA protein, rat; D007473:Ion Channels; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; C000603789:TMEM26 protein, rat; C000604371:UCP1 protein, human; C000604373:Ucp1 protein, rat; D000071256:Uncoupling Protein 1; D064429:Fatty Acid Synthases
keywords: Beige adipose tissue; Brown adipose tissue; Energy expenditure; Gastric bypass; Gene expression