title: Sclerostin and DKK1 levels during 14 and 21 days of bed rest in healthy young men.
abstract: OBJECTIVE
  Wnt signaling pathway may be crucial in the pathogenesis of disuse-induced bone loss. Sclerostin and DKK1, antagonists of the Wnt signaling pathway, were assessed during immobilization by bed rest in young, healthy people.
  
  
  METHODS
  Two bed rest studies were conducted at the German Aerospace Center in Cologne. 14 days of 6° head-down-tilt bed rest were applied to eight healthy young male test subjects in study 1 and 21 days of head-down-tilt bed rest to seven healthy male subjects in study 2.
  
  
  RESULTS
  Sclerostin levels increased in both studies during bed rest (study 1, 0.64±0.05 ng/ml to 0.69±0.04 ng/ml, P=0.014; study 2, 0.42±0.04 ng/ml to 0.47±0.04 ng/ml, P=0.008) and they declined at the end of the 14- and 21-day bed rest periods. DKK1 decreased during the bed rest period in study 1 (P<0.001) but increased during bed rest in study 2 (P=0.006). As expected, bone formation marker PINP decreased (study 1, P=0.013; study 2, P<0.001) and bone resorption marker NTX increased during bed rest (P<0.001).
  
  
  CONCLUSIONS
  Data suggest that the Wnt signaling pathway is involved in disuse-induced bone loss in young, healthy humans.
authors: German Aerospace Center (DLR), Institute of Aerospace Medicine, Linder Hoehe, 51147 Cologne, Germany. petra.frings-meuthen@dlr.de
authors: P
authors: P
authors: Frings-Meuthen
authors: G
authors: G
authors: Boehme
authors: A-M
authors: AM
authors: Liphardt
authors: N
authors: N
authors: Baecker
authors: M
authors: M
authors: Heer
authors: J
authors: J
authors: Rittweger
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000328:Adult; D001510:Bed Rest / Q000009:adverse effects / Q000379:methods*; D015415:Biomarkers / Q000097:blood; D019485:Bone Morphogenetic Proteins / Q000097:blood*; D001862:Bone Resorption / Q000097:blood; D018592:Cross-Over Studies; D015536:Down-Regulation / Q000502:physiology; D005819:Genetic Markers; D018475:Head-Down Tilt / Q000009:adverse effects / Q000502:physiology*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000097:blood*; D008297:Male; D015854:Up-Regulation / Q000502:physiology; D055815:Young Adult
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D015415:Biomarkers; D019485:Bone Morphogenetic Proteins; C501126:DKK1 protein, human; D005819:Genetic Markers; D036341:Intercellular Signaling Peptides and Proteins; C422903:SOST protein, human