Expression of connective tissue growth factor/hypertrophic chondrocyte-specific gene product 24 (CTGF/Hcs24/CCN2) during distraction osteogenesis.
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.
Kadota
Hiroaki
H
Science of Functional Recovery and Reconstruction, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan.
Nakanishi
Tohru
T
Asaumi
Koji
K
Yamaai
Tomoichiro
T
Nakata
Eiji
E
Mitani
Shigeru
S
Aoki
Kiyoshi
K
Aiga
Ayako
A
Inoue
Hajime
H
Takigawa
Masaharu
M
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
C526316:CCN2 protein, rat; D017874:Immediate-Early Proteins; D036341:Intercellular Signaling Peptides and Proteins; D012333:RNA, Messenger; D055513:Connective Tissue Growth Factor