@article{GriebschKernHansenetal.2022, author = {Griebsch, Nora-Isabell and Kern, Johanna and Hansen, Jonas and Rullmann, Michael and Luthardt, Julia and Helfmeyer, Stephanie and Dekorsy, Franziska J. and Soeder, Marvin and Hankir, Mohammed K. and Zientek, Franziska and Becker, Georg-Alexander and Patt, Marianne and Meyer, Philipp M. and Dietrich, Arne and Bl{\"u}her, Matthias and Ding, Yu-Shin and Hilbert, Anja and Sabri, Osama and Hesse, Swen}, title = {Central serotonin/noradrenaline transporter availability and treatment success in patients with obesity}, series = {Brain Sciences}, volume = {12}, journal = {Brain Sciences}, number = {11}, issn = {2076-3425}, doi = {10.3390/brainsci12111437}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-290294}, year = {2022}, abstract = {Serotonin (5-hydroxytryptamine, 5-HT) as well as noradrenaline (NA) are key modulators of various fundamental brain functions including the control of appetite. While manipulations that alter brain serotoninergic signaling clearly affect body weight, studies implicating 5-HT transporters and NA transporters (5-HTT and NAT, respectively) as a main drug treatment target for human obesity have not been conclusive. The aim of this positron emission tomography (PET) study was to investigate how these central transporters are associated with changes of body weight after 6 months of dietary intervention or Roux-en-Y gastric bypass (RYGB) surgery in order to assess whether 5-HTT as well as NAT availability can predict weight loss and consequently treatment success. The study population consisted of two study cohorts using either the 5-HTT-selective radiotracer [\(^{11}\)C]DASB to measure 5-HTT availability or the NAT-selective radiotracer [\(^{11}\)C]MRB to assess NAT availability. Each group included non-obesity healthy participants, patients with severe obesity (body mass index, BMI, >35 kg/m\(^2\)) following a conservative dietary program (diet) and patients undergoing RYGB surgery within a 6-month follow-up. Overall, changes in BMI were not associated with changes of both 5-HTT and NAT availability, while 5-HTT availability in the dorsal raphe nucleus (DRN) prior to intervention was associated with substantial BMI reduction after RYGB surgery and inversely related with modest BMI reduction after diet. Taken together, the data of our study indicate that 5-HTT and NAT are involved in the pathomechanism of obesity and have the potential to serve as predictors of treatment outcomes.}, language = {en} } @article{HoffmannEbertHankiretal.2021, author = {Hoffmann, Annett and Ebert, Thomas and Hankir, Mohammed K. and Flehmig, Gesine and Kl{\"o}ting, Nora and Jessnitzer, Beate and L{\"o}ssner, Ulrike and Stumvoll, Michael and Bl{\"u}her, Matthias and Fasshauer, Mathias and T{\"o}njes, Anke and Miehle, Konstanze and Kralisch, Susan}, title = {Leptin improves parameters of brown adipose tissue thermogenesis in lipodystrophic mice}, series = {Nutrients}, volume = {13}, journal = {Nutrients}, number = {8}, issn = {2072-6643}, doi = {10.3390/nu13082499}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-242787}, year = {2021}, abstract = {Lipodystrophy syndromes (LD) are a heterogeneous group of very rare congenital or acquired disorders characterized by a generalized or partial lack of adipose tissue. They are strongly associated with severe metabolic dysfunction due to ectopic fat accumulation in the liver and other organs and the dysregulation of several key adipokines, including leptin. Treatment with leptin or its analogues is therefore sufficient to reverse some of the metabolic symptoms of LD in patients and in mouse models through distinct mechanisms. Brown adipose tissue (BAT) thermogenesis has emerged as an important regulator of systemic metabolism in rodents and in humans, but it is poorly understood how leptin impacts BAT in LD. Here, we show in transgenic C57Bl/6 mice overexpressing sterol regulatory element-binding protein 1c in adipose tissue (Tg (aP2-nSREBP1c)), an established model of congenital LD, that daily subcutaneous administration of 3 mg/kg leptin for 6 to 8 weeks increases body temperature without affecting food intake or body weight. This is associated with increased protein expression of the thermogenic molecule uncoupling protein 1 (UCP1) and the sympathetic nerve marker tyrosine hydroxylase (TH) in BAT. These findings suggest that leptin treatment in LD stimulates BAT thermogenesis through sympathetic nerves, which might contribute to some of its metabolic benefits by providing a healthy reservoir for excess circulating nutrients.}, language = {en} }