백서에서의 신연 골형성술과 골절 치유과정에서의 Matrix Metallopreinase-1과 Transforming Growth Factor-β1의 발현

초록

Purpose: To evaluate the temporal and spatial expression of Transforming Growth Factor-β1 and Matrix Metalloproteinase-1 in distraction osteogenesis and fracture healing models. Materials and Methods: Distraction osteogenesis was performed on the tibial diaphyses of Sprague- Dawley rats (latent period for 1 week, distraction for 2 weeks). The rats were euthanized at each week and the level of mRNA expression was assessed by real-time RT PCR and immunohistochemical staining. Results: Although the level of TGF-β1 mRNA and MMP-1 mRNA expression was increased during distraction osteogenesis and fracture healing, the level of mRNA expression was significantly higher in the distraction phase in the distraction group than in the fracture healing group at the same phase. After the distraction phase, the level of mRNA expression in both groups decreased to the base line. The peak expression of mRNA was followed by that of TGF-β1 mRNA. Immunohistochemical staining revealed that TGF-β1 was expressed mainly in the osteoblast and endothelial cells, and MMP-1 was expressed mainly in the endothelial cells of the vessel. Conclusion: There is specific time sequence in the expression of TGF-β1 and MMP-1 during fracture healing and distraction osteogenesis. These results suggest that TGF-β1 expression might be associated with the angiogenesis induced by MMP-1 expression during new bone formation.

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