title: Molecular profiling of a simple rat model of open tibial fractures with hematoma and periosteum disruption.
abstract: Bone fractures are a worldwide public health concern. Therefore, improving understanding of the bone healing process at a molecular level, which could lead to the discovery of potential therapeutic targets, is important. In the present study, a model of open tibial fractures with hematoma disruption, periosteal rupture and internal fixation in 6-month-old male Wistar rats was established, in order to identify expression patterns of key genes and their protein products throughout the bone healing process. A tibial shaft fracture was produced using the three-point bending technique, the hematoma was drained through a 4-mm incision on the medial aspect of the tibia and the fracture stabilized by inserting a needle into the medullary canal. Radiographs confirmed that the induced fractures were diaphyseal and this model was highly reproducible (kappa inter-rater reliability, 0.82). Rats were sacrificed 5, 14, 21, 28 and 35 days post-fracture to obtain samples for histological, immunohistochemical and molecular analysis. Expression of interleukin-1β (Il-1β), transforming growth factor-β2 (Tgf-β2), bone morphogenetic protein-6 (Bmp-6), bone morphogenetic protein-7 (Bmp-7) and bone γ-carboxyglutamic acid-containing protein (Bglap) genes was determined by reverse transcription quantitative polymerase chain reaction and protein expression was evaluated by immunohistochemistry, while histological examination allowed characterization of the bone repair process.Il-1β showed a biphasic expression, peaking 5 and 28 days post-fracture. Expression ofTgf-β2,Bmp-6andBmp-7was restricted to the period 21 days post-fracture.Bglapexpression increased gradually, peaking 21 days post-fracture, although it was expressed in all evaluated stages. Protein expression corresponded with the increased expression of their corresponding genes. In conclusion, a clear and well-defined expression pattern of the evaluated genes and proteins was observed, where their maximal expression correlated with their known participation in each stage of the bone healing process.
authors.affiliation: Young Scientist and Cathedras Department, National Council of Science and Technology (CONACYT), Mexico City 03940, Mexico; Molecular Biology and Genomics Department, University Center for Health Sciences, University of Guadalajara, Guadalajara, Jalisco 44340, Mexico; Surgery Department, Health Science University Center, Autonomous University of Aguascalientes, Aguascalientes, Aguascalientes 20131, Mexico.
authors.forename: Jose Rafael
authors.initials: JR
authors.lastname: Villafan-Bernal
authors.affiliation: Molecular Biology and Genomics Department, University Center for Health Sciences, University of Guadalajara, Guadalajara, Jalisco 44340, Mexico; Health Sciences Department, Los Altos University Center at Tepatitlan, University of Guadalajara, Guadalajara, Jalisco 47620, Mexico.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Franco-De La Torre
authors.affiliation: Institute of Molecular Biology in Medicine and Gene Therapy, University Center for Health Sciences, University of Guadalajara, Guadalajara, Jalisco 44340, Mexico.
authors.forename: Ana Soledad
authors.initials: AS
authors.lastname: Sandoval-Rodriguez
authors.affiliation: Institute of Molecular Biology in Medicine and Gene Therapy, University Center for Health Sciences, University of Guadalajara, Guadalajara, Jalisco 44340, Mexico.
authors.forename: Juan
authors.initials: J
authors.lastname: Armendariz-Borunda
authors.affiliation: Molecular Biology and Genomics Department, University Center for Health Sciences, University of Guadalajara, Guadalajara, Jalisco 44340, Mexico.
authors.forename: Juan Luis
authors.initials: JL
authors.lastname: Alcala-Zermeno
authors.affiliation: Cancer Institute of Jalisco, Guadalajara, Jalisco 44280, Mexico.
authors.forename: Jose Alfonso
authors.initials: JA
authors.lastname: Cruz-Ramos
authors.affiliation: Technical and Industrial Teaching Center (CETI) Colomos, Guadalajara, Jalisco 44638, Mexico.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Lopez-Armas
authors.affiliation: Molecular Biology and Genomics Department, University Center for Health Sciences, University of Guadalajara, Guadalajara, Jalisco 44340, Mexico; Chronic and Degenerative Disease Institute, University Center for Health Sciences, University of Guadalajara, Guadalajara, Jalisco 44340, Mexico.
authors.forename: Blanca Estela
authors.initials: BE
authors.lastname: Ramirez-Bastidas
authors.affiliation: Methodological and Instrumental Disciplines Department, University Center for Health Sciences, University of Guadalajara, Guadalajara, Jalisco 44340, Mexico.
authors.forename: Gracia Viviana
authors.initials: GV
authors.lastname: González-Enríquez
authors.affiliation: Surgery Department, Health Science University Center, Autonomous University of Aguascalientes, Aguascalientes, Aguascalientes 20131, Mexico.
authors.forename: Emerson Armando
authors.initials: EA
authors.lastname: Collazo-Guzman
authors.affiliation: Surgery Department, Health Science University Center, Autonomous University of Aguascalientes, Aguascalientes, Aguascalientes 20131, Mexico.
authors.forename: Raigam Jafet
authors.initials: RJ
authors.lastname: Martinez-Portilla
authors.affiliation: Molecular Biology and Genomics Department, University Center for Health Sciences, University of Guadalajara, Guadalajara, Jalisco 44340, Mexico.
authors.forename: Sergio
authors.initials: S
authors.lastname: Sánchez-Enríquez
keywords: animal model; bone; bone morphogenetic proteins; bone proteins; gene expression; molecular characteristics; open fracture; osteocalcin; osteoporosis