Effect of estrogen receptor beta on the osteoblastic differentiation function of human periodontal ligament cells

ObjectiveTo investigate the effect of estrogen receptor beta (ERβ) on osteoblastic differentiation function of human periodontal ligament (hPDL) cells by measuring the alkaline phosphatase (ALP) activity and the production of osteocalcin (OCN) in vitro.DesignWe employed a short interfering RNA (siRNA) technique to inhibit ERβ expression in hPDL cells; the cells were cultured with a saturating concentration of 17β-estradiol (10−7 M). ALP activity was analysed by colorimetric assay using ALP kit and the amount of OCN was assessed by osteocalcin ELISA kit.ResultsIt was shown that estradiol significantly enhanced the ALP activity and the production of OCN in hPDL cells. However, the ALP activity and the production of OCN in hPDL-siERβ cells were not significantly changed after estradiol treatment.ConclusionsThese results indicate that ERβ may play important roles in estrogen-induced effects on osteoblastic differentiation function of PDL cells and estrogen influences the bone formation capacity of PDL cells mainly via ERβ.