@article{OstIgualGilColemanetal.2020,
  author    = {Ost, Mario and Igual Gil, Carla and Coleman, Verena and Keipert, Susanne and Efstathiou, Sotirios and Vidic, Veronika and Weyers, Miriam and Klaus, Susanne},
  title     = {Muscle-derived GDF15 drives diurnal anorexia and systemic metabolic remodeling during mitochondrial stress},
  series = {EMBO reports},
  volume    = {21},
  journal   = {EMBO reports},
  number    = {3},
  publisher = {Wiley},
  address   = {Hoboken},
  issn      = {1469-221X},
  doi       = {10.15252/embr.201948804},
  pages     = {14},
  year      = {2020},
  abstract  = {Mitochondrial dysfunction promotes metabolic stress responses in a cell-autonomous as well as organismal manner. The wasting hormone growth differentiation factor 15 (GDF15) is recognized as a biomarker of mitochondrial disorders, but its pathophysiological function remains elusive. To test the hypothesis that GDF15 is fundamental to the metabolic stress response during mitochondrial dysfunction, we investigated transgenic mice (Ucp1-TG) with compromised muscle-specific mitochondrial OXPHOS capacity via respiratory uncoupling. Ucp1-TG mice show a skeletal muscle-specific induction and diurnal variation of GDF15 as a myokine. Remarkably, genetic loss of GDF15 in Ucp1-TG mice does not affect muscle wasting or transcriptional cell-autonomous stress response but promotes a progressive increase in body fat mass. Furthermore, muscle mitochondrial stress-induced systemic metabolic flexibility, insulin sensitivity, and white adipose tissue browning are fully abolished in the absence of GDF15. Mechanistically, we uncovered a GDF15-dependent daytime-restricted anorexia, whereas GDF15 is unable to suppress food intake at night. Altogether, our evidence suggests a novel diurnal action and key pathophysiological role of mitochondrial stress-induced GDF15 in the regulation of systemic energy metabolism.},
  language  = {en}
}
@article{FranzOstOttenetal.2018,
  author    = {Franz, Kristina and Ost, Mario and Otten, Lindsey and Herpich, Catrin and Coleman, Verena and Endres, Anne-Sophie and Klaus, Susanne and M{\"u}ller-Werdan, Ursula and Norman, Kristina},
  title     = {Higher serum levels of fibroblast growth factor 21 in old patients with cachexia},
  series = {Nutrition : the international journal of applied and basic nutritional sciences},
  volume    = {63-64},
  journal   = {Nutrition : the international journal of applied and basic nutritional sciences},
  publisher = {Elsevier},
  address   = {New York},
  issn      = {0899-9007},
  doi       = {10.1016/j.nut.2018.11.004},
  pages     = {81 -- 86},
  year      = {2018},
  abstract  = {Objective: Fibroblast growth factor (FGF)21 is promptly induced by short fasting in animal models to regulate glucose and fat metabolism. Data on FGF21 in humans are inconsistent and FGF21 has not yet been investigated in old patients with cachexia, a complex syndrome characterized by inflammation and weight loss. The aim of this study was to explore the association of FGF21 with cachexia in old patients compared with their healthy counterparts. Methods: Serum FGF21 and its inactivating enzyme fibroblast activation protein (FAP)-cc were measured with enzyme-linked immunoassays. Cachexia was defined as >= 5\% weight loss in the previous 3 mo and concurrent anorexia (Council on Nutrition appetite questionnaire). Results: We included 103 patients with and without cachexia (76.9 +/- 5.2 y of age) and 56 healthy controls (72.9 +/- 5.9 y of age). Cachexia was present in 16.5\% of patients. These patients had significantly higher total FGF21 levels than controls (952.1 +/- 821.3 versus 525.2 +/- 560.3 pg/mL; P= 0.012) and the lowest FGF21 levels (293.3 +/- 150.9 pg/mL) were found in the control group (global P < 0.001). Although FAP-alpha did not differ between the three groups (global P = 0.082), bioactive FGF21 was significantly higher in patients with cachexia (global P = 0.002). Risk factor-adjusted regression analyses revealed a significant association between cachexia and total ((beta = 649.745 pg/mL; P < 0.001) and bioactive FGF21 (beta = 393.200 pg/mL; P <0.001), independent of sex, age, and body mass index. Conclusions: Patients with cachexia exhibited the highest FGF21 levels. Clarification is needed to determine whether this is an adaptive response to nutrient deprivation in disease-related cachexia or whether the increased FGF21 values contribute to the catabolic state. (C) 2018 Elsevier Inc. All rights reserved.},
  language  = {en}
}