Effect Of Pioglitazone On Expression Of MMP-9 MRNA In Human Osteoclast-like Cells Induced By RANKL And M-CSF In Vitro

Objective To investigate the effect of pioglitazone on expression of matrix metalloproteinase-9 (MMP-9) mRNA in human osteoclast-like cells(OLCs) induced by receptor activator of NF-κB ligand (RANKL) and human macrophage-colony stimulating factor(M-CSF) in vitro.Methods Mononuclear cells were isolated from human peripheral blood by density gradient centrifugation, then were cultured with medium containing RANKL and M-CSF. OLCs were identified by the tartrate-resistant acid phosphatase(TRAP)staining and scanning electron microscopy(SEM) was used to observe resorption pits on bone slices after 14 days. Subsequently, OLCs were incubated in various concentrations of pioglitazone(0,10-5 ,10-6,10-7mol/l) for 48 hours. Reverse transcription-polymerase chain reaction(RT-PCR) method was used to determine the expression level of MMP-9 mRNA.Results OLCs were induced in the presence of RANKL and M-CSF. These multinucleated cells were TRAP-positive and formed resorption pits on bone slices in vitro. MMP-9 mRNA expression was detectable in OLCs by RT-PCR method. After 48 hours exposure of OLCs to pioglitazone, expression level of MMP-9 mRNA decreased significantly compared to control group (P<0.01). At the same time, there were significant changes between different concentrations of pioglitazone groups(P<0.01).Conclusions RANKL and M-CSF can induce OLCs from human peripheral blood mononuclear cells. OLCs can express MMP-9 mRNA in vitro. Treatment with pioglitzone down regulates the expression of MMP-9 mRNA level in OLCs.