Abstract
It has been reported that β-TCP can stimulate bone formation, but the mechanisms are not well understood. The enhancement of bone formation and IGFs gene expression in bone defects of Beagle dog mandibles by β-TCP were reported. IGFs are the most abundant growth factors produced by osteoblasts, and exert important effects on the proliferation and differentiation of osteoblasts. However, the mechanism of activation of IGF signaling by β-TCP has not been elucidated. In this study, an implant drill was used to make bone defects in Beagle dog mandibles, and β-TCP was filled into the bone defects. The effect of β-TCP on IGF receptor 1 (IGF1R) gene expression was analyzed by RT-PCR and real-time PCR. Moreover, the gene products in mandibles were examined by immunohistochemistry. Increased mRNA levels of IGF1R gene were observed in β-TCP implanted samples compared with controls. The enhancement of IGF1R mRNA levels by β-TCP was confirmed by RT-PCR and real-time PCR. Immunohistochemical staining revealed increased IGF1R protein expression and phosphorylation in β-TCP-implanted bone tissue. Taken together, the stimulation of IGF1R expression and phosphorylation by β-TCP might be a part of the mechanism of accelerating bone formation.
