Oxidized low-density lipoprotein and upregulated expression of osteonectin and bone sialoprotein in vascular smooth muscle cells.

BACKGROUND: Oxidative stress has been associated with the progression of atherosclerosis and activation of genes that lead to increased deposition of proteins in the extracellular matrix. Bone sialoprotein (BSP) and osteonectin are proteins involved in the initiation and progression of vascular calcification.
OBJECTIVE: To investigate the effect of oxidized low-density lipoprotein on osteonectin and BSP expression in human aorta vascular smooth muscle cells (HA/VSMCs).
METHODS: We treated HA/VSMCs with oxidized low-density lipoprotein (oxLDL) and measured the relative expression of osteonectin and BSP genes using the real-time polymerase chain reaction (PCR) method. We investigated the protein levels produced by each gene using the western blotting technique.
RESULTS: oxLDL increased osteonectin and BSP levels (mean [SD], 9.1 [2.1]-fold and 4.2 [0.75]-fold, respectively) after 48 hours. The western blotting results also confirmed the increased levels of osteonectin and BSP.
CONCLUSION: oxLDL may enhance vascular calcification by promoting the expression of osteonectin and BSP. Copyright© by the American Society for Clinical Pathology (ASCP).