title: Human bone chips release of sclerostin and FGF-23 into the culture medium: an in vitro pilot study.
abstract: OBJECTIVE
  Signaling molecules derived from osteocytes have been proposed as a mechanism by which autografts contribute to bone regeneration. However, there have been no studies that determined the role of osteocytes in bone grafts.
  
  
  METHODS
  Herein, it was examined whether bone chips and demineralized bone matrix release sclerostin and FGF-23, both of which are highly expressed by osteocytes.
  
  
  RESULTS
  Bone grafts from seven donors were placed in culture medium. Immunoassay showed that bone chips released sclerostin (median 1.0 ng/ml) and FGF-23 (median 9.8 relative units/ml) within the first day, with declining levels overtime. Demineralized bone matrix also released detectable amounts of sclerostin into culture medium, while FGF-23 remained close to the detection limit. In vitro expanded isolated bone cells failed to release detectable amounts of sclerostin and FGF-23.
  
  
  CONCLUSIONS
  These results suggest that autografts but also demineralized bone matrix can release signaling molecules that are characteristically produced by osteocytes.
authors.affiliation: Department of Cranio-Maxillofacial Surgery, Inselspital, University of Bern, Bern, Switzerland.|Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Bern, Bern, Switzerland.
authors.forename: Eliane
authors.initials: E
authors.lastname: Brolese
authors.affiliation: Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Bern, Bern, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Buser
authors.affiliation: Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Bern, Bern, Switzerland.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Kuchler
authors.affiliation: Department of Cranio-Maxillofacial Surgery, Inselspital, University of Bern, Bern, Switzerland.
authors.forename: Benoit
authors.initials: B
authors.lastname: Schaller
authors.affiliation: Department of Oral Surgery and Stomatology, School of Dental Medicine, University of Bern, Bern, Switzerland.|Laboratory of Oral Cell Biology, School of Dental Medicine, University of Bern, Bern, Switzerland.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Gruber
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000328:Adult; D000368:Aged; D019485:Bone Morphogenetic Proteins / Q000032:analysis / Q000378:metabolism*; D018929:Cell Culture Techniques; D003470:Culture Media / Q000737:chemistry*; D005260:Female; D000089703:Fibroblast Growth Factor-23; D005346:Fibroblast Growth Factors / Q000032:analysis / Q000378:metabolism*; D005819:Genetic Markers; D006801:Humans; D008297:Male; D008875:Middle Aged; D010011:Osteocytes / Q000378:metabolism*; D010865:Pilot Projects; D055815:Young Adult
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D019485:Bone Morphogenetic Proteins; D003470:Culture Media; C000717427:FGF23 protein, human; D005819:Genetic Markers; C422903:SOST protein, human; D005346:Fibroblast Growth Factors; D000089703:Fibroblast Growth Factor-23
keywords: FGF-23; autologous bone; bone grafts; demineralized bone matrix; osteocytes; sclerostin