Different expressing levels of osteoprotegerin and receptor activator of nuclear factor-κB ligand from osteoblasts of young, adult and aged mice

Objective To investigate different expressing of OPG and RANKL expression from osteoblasts stimulated with estrogen of young, adult and aged mice changing with age. Method We employed RT-PCR and ELISA methods to measure the OPG/RANKL expression from osteoblasts before and after co-cultured with 17β-estradiol. Results OPG expressing from osteoblasts of the yound and adult mice was significantly increased after stimulated with estrogen, however, RANKL expressing wasn′t decreased significantly, compared to from osteoblasts of the aged. There were no significantly difference among osteoblasts co-cultured with methyl-piperidino-pyrazile (MPP). Conclusion Our results suggest that estrogen may exert its anti-resorptive effects on bone, at least in part, by increasing OPG and decreasing RANKL expression in osteoblasts. Decreased OPG and increased RANKL may be one of important reeasons of postmenopausal osteoporosis.