@article{DischingerHeckelBischleretal.2021,
  author    = {Dischinger, Ulrich and Heckel, Tobias and Bischler, Thorsten and Hasinger, Julia and K{\"o}nigsrainer, Malina and Schmitt-B{\"o}hrer, Angelika and Otto, Christoph and Fassnacht, Martin and Seyfried, Florian and Hankir, Mohammed Khair},
  title     = {Roux-en-Y gastric bypass and caloric restriction but not gut hormone-based treatments profoundly impact the hypothalamic transcriptome in obese rats},
  series = {Nutrients},
  volume    = {14},
  journal   = {Nutrients},
  number    = {1},
  issn      = {2072-6643},
  doi       = {10.3390/nu14010116},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-252392},
  year      = {2021},
  abstract  = {Background: The hypothalamus is an important brain region for the regulation of energy balance. Roux-en-Y gastric bypass (RYGB) surgery and gut hormone-based treatments are known to reduce body weight, but their effects on hypothalamic gene expression and signaling pathways are poorly studied. Methods: Diet-induced obese male Wistar rats were randomized into the following groups: RYGB, sham operation, sham + body weight-matched (BWM) to the RYGB group, osmotic minipump delivering PYY3-36 (0.1 mg/kg/day), liraglutide s.c. (0.4 mg/kg/day), PYY3-36 + liraglutide, and saline. All groups (except BWM) were kept on a free choice of high- and low-fat diets. Four weeks after interventions, hypothalami were collected for RNA sequencing. Results: While rats in the RYGB, BWM, and PYY3-36 + liraglutide groups had comparable reductions in body weight, only RYGB and BWM treatment had a major impact on hypothalamic gene expression. In these groups, hypothalamic leptin receptor expression as well as the JAK-STAT, PI3K-Akt, and AMPK signaling pathways were upregulated. No significant changes could be detected in PYY3-36 + liraglutide-, liraglutide-, and PYY-treated groups. Conclusions: Despite causing similar body weight changes compared to RYGB and BWM, PYY3-36 + liraglutide treatment does not impact hypothalamic gene expression. Whether this striking difference is favorable or unfavorable to metabolic health in the long term requires further investigation.},
  language  = {en}
}
@article{MetznerHerzogHeckeletal.2022,
  author    = {Metzner, Valentin and Herzog, Gloria and Heckel, Tobias and Bischler, Thorsten and Hasinger, Julia and Otto, Christoph and Fassnacht, Martin and Geier, Andreas and Seyfried, Florian and Dischinger, Ulrich},
  title     = {Liraglutide + PYY\(_{3-36}\) combination therapy mimics effects of Roux-en-Y bypass on early NAFLD whilst lacking-behind in metabolic improvements},
  series = {Journal of Clinical Medicine},
  volume    = {11},
  journal   = {Journal of Clinical Medicine},
  number    = {3},
  issn      = {2077-0383},
  doi       = {10.3390/jcm11030753},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-255244},
  year      = {2022},
  abstract  = {Background: Treatment options for NAFLD are still limited. Bariatric surgery, such as Roux-en-Y gastric bypass (RYGB), has been shown to improve metabolic and histologic markers of NAFLD. Glucagon-like-peptide-1 (GLP-1) analogues lead to improvements in phase 2 clinical trials. We directly compared the effects of RYGB with a treatment using liraglutide and/or peptide tyrosine tyrosine 3-36 (PYY\(_{3-36}\)) in a rat model for early NAFLD. Methods: Obese male Wistar rats (high-fat diet (HFD)-induced) were randomized into the following treatment groups: RYGB, sham-operation (sham), liraglutide (0.4 mg/kg/day), PYY\(_{3-36}\) (0.1 mg/kg/day), liraglutide+PYY\(_{3-36}\), and saline. After an observation period of 4 weeks, liver samples were histologically evaluated, ELISAs and RNA sequencing + RT-qPCRs were performed. Results: RYGB and liraglutide+PYY\(_{3-36}\) induced a similar body weight loss and, compared to sham/saline, marked histological improvements with significantly less steatosis. However, only RYGB induced significant metabolic improvements (e.g., adiponectin/leptin ratio 18.8 ± 11.8 vs. 2.4 ± 1.2 in liraglutide+PYY\(_{3-36}\)- or 1.4 ± 0.9 in sham-treated rats). Furthermore, RNA sequencing revealed a high number of differentially regulated genes in RYGB treated animals only. Conclusions: The combination therapy of liraglutide+PYY\(_{3-36}\) partly mimics the positive effects of RYGB on weight reduction and on hepatic steatosis, while its effects on metabolic function lack behind RYGB.},
  language  = {en}
}
@article{DischingerHasingerKoenigsraineretal.2021,
  author    = {Dischinger, Ulrich and Hasinger, Julia and K{\"o}nigsrainer, Malina and Corteville, Carolin and Otto, Christoph and Fassnacht, Martin and Hankir, Mohamed and Seyfried, Florian Johannes David},
  title     = {Toward a Medical Gastric Bypass: Chronic Feeding Studies With Liraglutide + PYY\(_{3-36}\) Combination Therapy in Diet-Induced Obese Rats},
  series = {Frontiers in Endocrinology},
  volume    = {11},
  journal   = {Frontiers in Endocrinology},
  issn      = {1664-2392},
  doi       = {10.3389/fendo.2020.598843},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-223113},
  year      = {2021},
  abstract  = {Background Combination therapies of anorectic gut hormones partially mimic the beneficial effects of bariatric surgery. Thus far, the effects of a combined chronic systemic administration of Glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine 3-36 (PYY\(_{3-36}\)) have not been directly compared to Roux-en-Y gastric bypass (RYGB) in a standardized experimental setting. Methods High-fat diet (HFD)-induced obese male Wistar rats were randomized into six treatment groups: (1) RYGB, (2) sham-operation (shams), (3) liraglutide, (4) PYY\(_{3-36}\), (5) PYY\(_{3-36}\)+liraglutide (6), saline. Animals were kept on a free choice high- and low-fat diet. Food intake, preference, and body weight were measured daily for 4 weeks. Open field (OP) and elevated plus maze (EPM) tests were performed. Results RYGB reduced food intake and achieved sustained weight loss. Combined PYY\(_{3-36}\)+liraglutide treatment led to similar and plateaued weight loss compared to RYGB. Combined PYY\(_{3-36}\)+liraglutide treatment was superior to PYY\(_{3-36}\) (p ≤ 0.0001) and liraglutide (p ≤ 0.05 or p ≤ 0.01) mono-therapy. PYY\(_{3-36}\)+liraglutide treatment and RYGB also reduced overall food intake and (less pronounced) high-fat preference compared to controls. The animals showed no signs of abnormal behavior in OF or EPM. Conclusions Liraglutide and PYY\(_{3-36}\) combination therapy vastly mimics reduced food intake, food choice and weight reducing benefits of RYGB.},
  language  = {en}
}