Effects of low density lipoproteins on mouse osteoblast

Objective To investigate the effect of low density lipoprotein(LDL) on the proliferation and differentiation of mouse osteoblasts and related mechanism.Methods Mouse osteoblasts MC3T3-E1 were cultured with low density lipoprotein(LDL) at concentration of 0.05,0.1 and 0.2 mg/ml,respectively.The proliferation and differentiation of MC3T3-E1osteoblasts were detected with CCK-8 after treated with LDL for 24,48 and 72h.The osteocalcin levels were detected by ELISA and the expression of LDL receptor-related protein 5(LRP5) and dickkopf-1(DKK1),were detected by real-time PCR.Results The proliferation of osteoblasts was significantly suppressed by LDL treatment in a dose-and time-dependence manner(P0.05).ELISA showed that osteocalcin expression was inhibited by LDL with a dose-and time-dependence manner(P0.05).Real-Time PCR results exhibited that expression of LRP5 mRNA was up-regulated and expression of DKK1 mRNA was down-regulated with 0.05 mg/ml LDL for 48h(P0.05).Conclusion LDL can suppress the proliferation and differentiation of osteoblasts,which might be correlated with the up-regulation of LRP5 gene and down-regulation of its antagonist DKK1 gene in the wnt signal passageway.