The study on the inhibitive effects of recombinant parathyroid hormone (1-34) on osteolysis in a murine calvarial model induced by wear particles

Abstract

Objective: To investigate the effect of different doses of recombinant parathyroid hormone (PTH) (1-34) on osteolysis in a murine calvarial model. Methods: In total, 48 adult male C57BL/J6 mice were randomly divided into four groups: the sham group, the vehicle group, the low dose-, and high dose PTH group (n=12 each group). Mice in the PTH groups were treated with local injection of recombinant PTH at 30 or 60 μg·kg-1·d-1, intermittent injection 3 times per week for two weeks. Mice in the sham and vehicle groups received local injection of saline daily. Two weeks after surgery, calvarial tissue and peripheral blood were harvested for further analysis. Osteolysis was assessed by micro-computed tomography. The mRNA and protein expression of osteoprotegerin (OPG) and receptor activator for nuclear factor-κB Ligand (RANKL) of calvarial tissue and peripheral blood were tested by real-time PCR and ELISA, respectively. Results: Compared with the vehicle group, PTH treatment significantly inhibited the severity of osteolysis and improved the bone volume. Real time-PCR and ELISA showed that PTH significantly increased the mRNA and protein expression of OPG and reduced the RANKL/OPG ratio. Conclusion: These findings suggest that local application of PTH could effectively inhibit wear-particle-induced-osteolysis in a murine calvarial model.