Abstract
Prostaglandin E2 (PGE2), which is considered to be an important local factor in bone metabolism, stimulates alkaline phosphatase (ALP) activity in dental pulp (HDP) cells at lower concentrations. Moreover, insulin-like growth factors (IGFs) are widely expressed abundant autocrine and paracrine factors that regulate the proliferation and differentiation of various cells. PGE2 is also a potent stimulator of IGFs synthesis in bone formation. In this study, we examined the effect of PGE2 on IGF induction in HDP cells. PGE2 increased IGF-1 and IGFBP-5 mRNA level and production as compared to the control, and IGF-1 and IGFBP-5 significantly increased the ALP activities in a dose-dependent manner. On the other hand, the addition of the anti-IGF-1 antibody decreased ALP activity by PGE2. These findings suggest that PGE2 stimulates the formation of tertiary dentin through induction of IGF-1 and IGFBP-5 expressions in HDP cells.
