Effect Of Alendronate On The Differentiation And Generation Of Osteoclast Stimulated By Wear Debris

ObjectiveTo explore the effect of alendronate on the differentiation of osteoclast from osteoclast precursors (OCPs) stimulated by wear debris, and provide more evidences for bisphosphonate on the treatment of aseptic loosening of prosthesis.MethodsOCPs were induced from hematopoietic stem cells in the presence of macrophage colony stimulating factor(M- CSF), and then OCPs were induced to Osteoclast cells in the presence of M-CSF and receptor activator of NF-κB ligand (RANKL), and then polyethylene and alendronate were added to the culture medium as follows. GroupA:only OCPs. GroupB:OCPs+106/mlUHMWPE. GroupC:OCPs +106/ml UHMWPE +0.4μg/ml alendronate. GroupD: OCPs+106/ml UHMWPE +2μg/ml alendronate. GroupE:OCPs + 106/ml UHMWPE + 10μg/ml alendronate. Group F: OCPs+ 106/ml UHMWPE +50μg/ml alendronate. Cell toxicity assays were performed using the CCK-8 kit , following the manufacturer's instruction ;Tartrate-resistant acid phosphatase staining(TRAP)was used and multinucleated (≥3 nuclei) TRAP-positive cells were counted as osteoclasts; then expression of TRAP mRNA was determined by RT-PCR techniques.ResultsDifferent concentration alendronates (0.4μg/ml,2μg/ml,10μg/ml,50μg/ml) have no cytotoxicity;The number of multinucleated (≥3 nuclei) TRAP-positive cells from the polyethylene group is significantly higher than control group, and alendronate groups are all lower than the polyethylene group, and with the increase of the concentration of the alendronate, the number of TRAP+ osteoclasts comes down(P<0.05);The expression of TRAP mRNA from the polyethylene group is significantly higher than the control group, and alendronate groups are all lower than the polyethylene group, and with the increase of the concentration of the alendronate, the expression of TRAP mRNA comes down(P<0.05).Conclusionbisphosphonate can inhibit the differentiation of osteoclast from osteoclast precursors stimulated by wear debris.