title: Expression of connective tissue growth factor/hypertrophic chondrocyte-specific gene product 24 (CTGF/Hcs24/CCN2) during distraction osteogenesis.
abstract: To investigate the localization and expression of connective tissue growth factor/hypertrophic chondrocyte-specific gene product 24/CCN family member 2 (CTGF/Hcs24/CCN2) during distraction osteogenesis in the rat femur, we studied a total of 54 male rats (11 weeks old). We performed osteotomy in the midshaft of the right femur. After 7 days (lag phase), distraction was started, at the rate of 0.25 mm/12 h for 21 days (distraction phase) by using a small external fixator, and this was followed by a 7-day consolidation phase. Localization and expression of CTGF/Hcs24 during distraction osteogenesis in the femur were examined by immunostaining, in situ hybridization, and reverse transcriptase polymerase chain reaction (RT-PCR). Immunostaining showed the localization of CTGF/Hcs24 in various cells located in the bone-forming area around the osteotomy site. During the distraction phase, in situ hybridization showed that CTGF/Hcs24 mRNA was expressed not only in hypertrophic chondrocytes and osteoblasts but also in fibroblast-like cells and mesenchymal cells at sites of end-ochondral ossification, and not only in osteoblasts but also in pre-osteoblasts and fibroblast-like cells at sites of intramembranous ossification. RT-PCR showed higher level expression of CTGF/Hcs24 mRNA in the distracted group than in the nondistracted group. These results revealed an elevated pattern of CTGF/Hcs24 mRNA expression during distraction osteogenesis, and suggest that CTGF/Hcs24 may play some roles in the endochondral and intramembranous ossification processes that occur during distraction osteogenesis.
authors.affiliation: Science of Functional Recovery and Reconstruction, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kadota
authors.forename: Tohru
authors.initials: T
authors.lastname: Nakanishi
authors.forename: Koji
authors.initials: K
authors.lastname: Asaumi
authors.forename: Tomoichiro
authors.initials: T
authors.lastname: Yamaai
authors.forename: Eiji
authors.initials: E
authors.lastname: Nakata
authors.forename: Shigeru
authors.initials: S
authors.lastname: Mitani
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Aoki
authors.forename: Ayako
authors.initials: A
authors.lastname: Aiga
authors.forename: Hajime
authors.initials: H
authors.lastname: Inoue
authors.forename: Masaharu
authors.initials: M
authors.lastname: Takigawa
mesh_terms: D000818:Animals; D055513:Connective Tissue Growth Factor; D005269:Femur / Q000000981:diagnostic imaging / Q000378:metabolism; D017874:Immediate-Early Proteins / Q000235:genetics* / Q000378:metabolism; D017403:In Situ Hybridization; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism; D008297:Male; D019857:Osteogenesis, Distraction; D010027:Osteotomy; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011859:Radiography; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: C526316:CCN2 protein, rat; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D055513:Connective Tissue Growth Factor