title: Osteoclastic resorptive capacity is suppressed in patients receiving hyperbaric oxygen therapy.
abstract: OBJECTIVE
  Hypoxia, necrosis, and bone loss are hallmarks of many skeletal diseases. Hyperbaric oxygen therapy (HBO) is often used as an adjunctive therapy in these cases. However the in vivo effect of HBO on osteoclast formation has not been fully established. We therefore carried out a longitudinal study to examine the effect of HBO on osteoclast formation and bone resorptive capacity in patients who were referred to the Plymouth Hyperbaric Medical Centre.
  
  
  METHODS
  Osteoclast precursors were isolated from peripheral blood prior to and following 10 and 25 daily hyperbaric treatments (100% O2 at 2.4 atmospheres absolute ATA for 90 min) to determine osteoclast formation and resorptive capacity. The expression of key regulators of osteoclast differentiation RANK, Dc-STAMP, and NFATc1 was also assessed by quantitative real-time PCR.
  
  
  RESULTS
  HBO reduced the ability of precursors to form osteoclasts and reduced bone resorption in a treatment-dependent manner. The initial suppressive effect of HBO was more pronounced on mononuclear osteoclast formation than on multinuclear osteoclast formation, and this was accompanied by reduction in the expression of key regulators of osteoclast formation, RANK and Dc-STAMP.
  
  
  CONCLUSIONS
  This study shows for the first time that in vivo, HBO suppresses the ability of monocytic precursors to form resorptive osteoclasts.
authors.affiliation: School of Biomedical and Healthcare Sciences, Plymouth University.
authors.forename: Hadil Al
authors.initials: HA
authors.lastname: Hadi
authors.forename: Gary
authors.initials: G
authors.lastname: Smerdon
authors.forename: Simon W
authors.initials: SW
authors.lastname: Fox
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics; D000368:Aged; D000369:Aged, 80 and over; D001862:Bone Resorption / Q000378:metabolism*; D002454:Cell Differentiation; D002478:Cells, Cultured; D002908:Chronic Disease; D005786:Gene Expression Regulation; D006801:Humans; D006931:Hyperbaric Oxygenation; D008137:Longitudinal Studies; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D008875:Middle Aged; D009000:Monocytes / Q000166:cytology / Q000378:metabolism*; D050778:NFATC Transcription Factors / Q000235:genetics; D010010:Osteoclasts / Q000166:cytology / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D011832:Radiation Injuries / Q000628:therapy*; D060888:Real-Time Polymerase Chain Reaction; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000235:genetics; D014947:Wounds and Injuries / Q000628:therapy*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C501589:DCSTAMP protein, human; D008565:Membrane Proteins; D050778:NFATC Transcription Factors; C494003:NFATC1 protein, human; D012333:RNA, Messenger; D053246:Receptor Activator of Nuclear Factor-kappa B; C505686:TNFRSF11A protein, human