Mohammed K Hankir1, Felix Bronisch1, Constantin Hintschich1, Ute Krügel2, Florian Seyfried3, Wiebke K Fenske4. 1. Integrated Research and Treatment Centre for Adiposity Diseases, Department of Medicine, University of Leipzig, Leipzig, Germany. 2. Rudolf Boehm Institute of Pharmacology and Toxicology, Department of Medicine, University of Leipzig, Leipzig, Germany. 3. Department of General, Visceral, Vascular Pediatric Surgery, University of Würzburg, Würzburg, Germany. 4. Integrated Research and Treatment Centre for Adiposity Diseases, Department of Medicine, University of Leipzig, Leipzig, Germany. Electronic address: wiebkekristin.fenske@medizin.uni-leipzig.de.
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. CONCLUSION: 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.
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. CONCLUSION: 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: Malini S Iyer; Rebecca L Paszkiewicz; Richard N Bergman; Joyce M Richey; Orison O Woolcott; Isaac Asare-Bediako; Qiang Wu; Stella P Kim; Darko Stefanovski; Cathryn M Kolka; Deborah J Clegg; Morvarid Kabir Journal: Am J Physiol Endocrinol Metab Date: 2019-06-25 Impact factor: 4.310
Authors: Mohammed K Hankir; Marianne Patt; Jörg T W Patt; Georg A Becker; Michael Rullmann; Mathias Kranz; Winnie Deuther-Conrad; Kristin Schischke; Florian Seyfried; Peter Brust; Swen Hesse; Osama Sabri; Ute Krügel; Wiebke K Fenske Journal: Front Neurosci Date: 2017-01-13 Impact factor: 4.677