Effects of epidermal growth factor and transforming growth factor-beta on insulin-induced differentiation in rat dental pulp cells.
An established pulp cell line (RPC-C2A) was used to study the regulatory effect of insulin on dentinogenesis. Insulin increased alkaline phosphatase activity and the incorporation of [2,3-3H]-proline into collagenase-digestible protein, whereas [3H]-thymidine incorporation by the cells was inhibited by insulin. The enhancing effect of insulin on alkaline phosphatase activity was inhibited by epidermal growth factor (EGF) or transforming growth factor-beta (TGF-beta). The stimulatory effect of insulin on collagen synthesis was also inhibited when insulin was combined with EGF, but was accelerated by the addition of TGF-beta. Inhibitory effects of insulin on the [3H]-thymidine incorporation were potentiated by EGF, though EGF alone strongly increased the effect; whereas the addition of TGF-beta had no significant effect on the insulin action. These findings suggest that insulin may be concerned with the differentiation of pulp cells in dentinogenesis and that EGF or TGF-beta regulate the insulin effects.
Liang
R F
RF
Department of Pharmacology, Meikai University School of Dentistry, Saitama, Japan.
Nishimura
S
S
Sato
S
S
D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D003094:Collagen / Q000096:biosynthesis; D003782:Dental Pulp / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D003810:Dentinogenesis / Q000187:drug effects*; D004815:Epidermal Growth Factor / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D016212:Transforming Growth Factor beta / Q000494:pharmacology
D007328:Insulin; D016212:Transforming Growth Factor beta; D004815:Epidermal Growth Factor; D003094:Collagen; D000469:Alkaline Phosphatase