Objectives: Growth/differentiation factor-5 (GDF-5), a member of TGF-b superfamily, is known to play a role in embryonic skeletal formation such as endochondral ossification, synovial joint formation. Expression of GDF-5 mRNA was also reported in odontogenesis, especially in dental follicle tissue. The purpose of present study was to investigate the effects of recombinant human GDF-5 (rhGDF-5) on adult murine carvarial bone in vivo in histochemical comparison with endochondral ossification at long bone. Cellular response was also examined in vitro. Methods: In vivo study: ddY mice (8 weeks, male, Kyudou, Co, Ltd) were injected rhGDF-5 with neutralized atelo collagen gel (3 mg/ml, pH 7.0, Cellmatrix LA®, Nitta Gelatin, Inc, Osaka, Japan). The mice were sacrificed on 3-28 days after injection. After fixation and demineralization the specimens were embedded in paraffin. 6μm thick serial sections were cut on a microtome. For histochemical analysis haematoxyline and eosin stain (H.E.), alcian blue stain (A.B), tartrate-resistant acid phosphatase stain (TRAP), and immunohistochemical stain were performed. Epiphyseal plate at femur was observed as a typical tissue of endochondral ossification. In vitro study: Enzymatically isolated murine calvarial cells were analyzed for cell proliferation by MTT assay in the presence or absence of rhGDF-5. Results: in vitro study: After 6 days in culture with addition of rhGDF-5, cell numbers had increased significantly in a dose-dependent manner compared with those of cells unexposed to rhGDF-5. in vivo study:Histological analysis illustrated de novo bone formation on the injected surface. Typical cartilage tissue was confirmed by H.E. and A.B. stain. Consistent with epiphyseal plate, cartilage-related molecules such as type II collagen (immunohistochemical stain) and aggrecan(A.B.) were positively stained on section of augmented bone. Cells stained against prolifelating cell nuclear antigen (PCNA) were also detected. Conclusion: Bone formation on carvalial surface by rhGDF-5 was similar to endochondral ossification at epiphyseal plate.
Division: Japanese Division Meeting
Meeting:2004 Japanese Division Meeting (Tokyo, Japan) Location: Tokyo, Japan
Year: 2004 Final Presentation ID:34 Abstract Category|Abstract Category(s):Scientific Groups
Authors
Yoshimoto, Takehiko
( Kagoshima university, Kagoshima, N/A, Japan
)
Yamamoto, Matsuo
( Kagoshima university, Kagoshima, N/A, Japan
)
Izumi, Yuichi
( Kagoshima university, Kagoshima, N/A, Japan
)