title: In vivo hypobaric hypoxia performed during the remodeling process accelerates bone healing in mice.
abstract: We investigated the effects of respiratory hypobaric hypoxia on femoral bone-defect repair in mice because hypoxia is believed to influence both mesenchymal stromal cell (MSC) and hematopoietic stem cell mobilization, a process involved in the bone-healing mechanism. To mimic conditions of non-weight-bearing limb immobilization in patients suffering from bone trauma, our hypoxic mouse model was further subjected to hind-limb unloading. A hole was drilled in the right femur of adult male C57/BL6J mice. Four days after surgery, mice were subjected to hind-limb unloading for 1 week. Seven days after surgery, mice were either housed for 4 days in a hypobaric room (FiO2 at 10%) or kept under normoxic conditions. Unsuspended control mice were housed in either hypobaric or normoxic conditions. Animals were sacrificed on postsurgery day 11 to allow for collection of both contralateral and lesioned femurs, blood, and spleen. As assessed by microtomography, delayed hypoxia enhanced bone-healing efficiency by increasing the closing of the cortical defect and the newly synthesized bone volume in the cavity by +55% and +35%, respectively. Proteome analysis and histomorphometric data suggested that bone-repair improvement likely results from the acceleration of the natural bone-healing process rather than from extended mobilization of MSC-derived osteoprogenitors. Hind-limb unloading had hardly any effect beyond delayed hypoxia-enhanced bone-healing efficiency.
authors.affiliation: Département Soutien Médico-Chirugical des Forces, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge, France; Centre de Transfusion Sanguine des Armées, Service de Recherche, Clamart, France; INSERM U972, Hôpital Paul Brousse, Villejuif, France.
authors.forename: Marjorie
authors.initials: M
authors.lastname: Durand
authors.affiliation: Département Soutien Médico-Chirugical des Forces, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge, France; Centre de Transfusion Sanguine des Armées, Service de Recherche, Clamart, France; INSERM U972, Hôpital Paul Brousse, Villejuif, France.
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Collombet
authors.affiliation: Département Soutien Médico-Chirugical des Forces, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge, France; Centre de Transfusion Sanguine des Armées, Service de Recherche, Clamart, France; INSERM U972, Hôpital Paul Brousse, Villejuif, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Frasca
authors.affiliation: Département Soutien Médico-Chirugical des Forces, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge, France; Centre de Transfusion Sanguine des Armées, Service de Recherche, Clamart, France; INSERM U972, Hôpital Paul Brousse, Villejuif, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Begot
authors.affiliation: Département Soutien Médico-Chirugical des Forces, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge, France; Centre de Transfusion Sanguine des Armées, Service de Recherche, Clamart, France; INSERM U972, Hôpital Paul Brousse, Villejuif, France.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Lataillade
authors.affiliation: Département Soutien Médico-Chirugical des Forces, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge, France; Centre de Transfusion Sanguine des Armées, Service de Recherche, Clamart, France; INSERM U972, Hôpital Paul Brousse, Villejuif, France.
authors.forename: Marie-Caroline
authors.initials: MC
authors.lastname: Le Bousse-Kerdilès
authors.affiliation: Département Soutien Médico-Chirugical des Forces, Institut de Recherche Biomédicale des Armées (IRBA), Brétigny-sur-Orge, France; Centre de Transfusion Sanguine des Armées, Service de Recherche, Clamart, France; INSERM U972, Hôpital Paul Brousse, Villejuif, France xavier.holy@irba.fr.
authors.forename: Xavier
authors.initials: X
authors.lastname: Holy
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D016723:Bone Remodeling; D004195:Disease Models, Animal; D005264:Femoral Fractures / Q000150:complications* / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology; D005269:Femur / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D017102:Fracture Healing; D006412:Hematopoietic Stem Cells / Q000378:metabolism; D019417:Hindlimb Suspension; D000860:Hypoxia / Q000150:complications*; D008297:Male; D059630:Mesenchymal Stem Cells / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D040901:Proteomics; D013997:Time Factors; D055114:X-Ray Microtomography
chemical_list: D015415:Biomarkers
keywords: Bone healing; Hematopoietic progenitor cells; Hind-limb unloading; Hypobaric respiratory hypoxia; Mesenchymal stromal cells