ABSTRACT
Objective The aim of this study was to investigate the possible effect of glycated low density lipoprotein ( LDL ) on the proliferation, differentiation, and expression of low-density lipoprotein receptor-related protein5(LRP5)mRNA,dickkopf-1(DKK1)mRNAinmouseosteoblasts(MC3T3-E1cells). WhethertheWnt signaling pathway was involved in the above process was explored else. Methods Mouse MC3T3-E1 cells were culturedwithvariousconcentrationsofglycatedLDL(glycatedLDLlevelwas2.4%,5.3%,8.7%,13.9%)for24, 48, 72 h. Proliferation of MC3T3-E1 cell was measured by CCK-8, the osteocalcin level in the medium was determined by ELISA and the expression of LRP5 mRNA, DKK1 mRNA was measured by realtime PCR. Results After cells being incubated with 5. 3% of glycated LDL for 24 h, the inhibition of MC3T3-E1 cells was more marked than that in control group(P<0. 01). The higher glycated LDL level, the severer the inhibition. The effect of LDL on the MC3T3-E1 cell proliferation was time- and dose-dependent under certain conditions. Osteocalcin level in cell culture fluid with glycated LDL was lowered significantly compared with control group. Meanwhile, the expression of DKK1 mRNA was increased significantly but expression of LRP5 mRNA decreased (P<0. 01) in MC3T3-E1 cells cultured with 5. 3% of glycated LDL for 24 h. Conclusions Proliferation and differentiation of the osteoblasts in mice can be inhibited significantly by glycated LDL. The possible mechanism in the role played by glycated LDL on the proliferation and differentiation in MC3T3-E1 cells seems to be related to expression of LRP5 mRNA, DKK1 mRNA in the Wnt signaling pathway.