Abstract: Objective This research explores the regulatory role of bone morphogenetic protein 2 (BMP2) in the expression of sclerostin in OCCM-30 cementoblast. Methods OCCM-30 cementoblasts were treated with 50 and 100 ng·mL^-1 BMP2 for 3, 5, and 7 days. SOST mRNA was detected by real-time quantitative polymerase chain reaction (RT-PCR). Western blot analysis was employed to detect the sclerostin levels in the nucleus. Five groups were prepared for the experiments: control, BMP2, BMP2+dorsomorphin, BMP2+SB202190, and BMP2+PD98059. OCCM-30 was pretreated with BMP2 for 3 and 5 days, and then the sclerostin and SOST mRNA levels were measured. Results RT-PCR and Western blot analyses showed that BMP2 upregulated the expression of SOST in a concentration-dependent manner. SOST expression increased with time (P<0.05). Moreover, sclerostin levels of BMP2+dorsomorphin, BMP2+SB202190, and BMP2+PD98059 groups were lower than that of the BMP2 group, and the sclerostin level in BMP2+dorsomorphin group was lowest (P<0.05). Conclusion The upregulation of SOST by BMP2 in OCCM-30 is mainly mediated by the BMP2/Smad signal pathway.

Key words: cementoblast, bone morphogenetic protein 2, sclerostin, Smad signal pathway, root repair