REGULATORY EFFECT OF ESTROGEN RECEPTOR-α-MEDIATED Wnt/β-CATENIN SIGNALING PATHWAY ON OSTEOBLAST PROLIFERATION

This study was designed to investigate the regulatory effect of estrogen receptor-alpha (ER alpha)-mediated Wnt/beta-catenin signaling pathway on osteoblast proliferation. Mc3T3-El cells were infected by ER alpha and ER beta small interfering ribose nucleic acid (siRNA) viruses and treated with estradiol 2 (E2) for 120 min after 24-h infection. Western blot was used to detect expressions of beta-catenin, Gsk 3 beta, p-Gsk3 beta (Ser9) and CyclinD1; and methyl thiazolyl tetrazolium (MTT) was applied to detect osteoblast proliferation after interference by different ERs. Western blot results indicated that the expressions of beta-catenin, p-Gsk3 beta (Ser9) and CyclinD1 decreased after ER beta interference and ER alpha + ER beta joint interference, and a more obvious decrease was found after the joint interference. After ER beta interference, beta-catenin, p-Gsk3 beta (Ser9) and CyclinD1 were strongly expressed compared with expressions in the blank control group. MTT results demonstrated that the proliferation rate of osteoblast was lower after the joint interference than after ER beta interference, while a slight increase was found in the proliferation rate after ER beta interference in comparison with the blank control group. It can be concluded that estradiol is able to promote the proliferation of osteoblasts in mice by ER alpha-mediated Wnt/beta-catenin signaling pathway.