The current study aims to probe the changes in matrix metallopeptidase 9 (MMP-9)expression during differentiation as the mononuclear cell line THP-1 is converted into foam cells, as well as the underlying influence and mechanism of rosuvastatin.PMA was used to induce THP-1 cells transform into macrophages and treated with various concentrations, whereas rosuvastatin different concentrations were used for the intervention. Reverse transcription polymerase chain reaction and Western blot were adopted to detect the changes in MMP-9, extracellular-signal-regulated kinases (ERK) and pERK expressions in the cells of each group after the intervention of rosuvastatin. The expression of MMP-9 protein increased significantly in the conversion of THP-1 mononuclear macrophages into foam cells, and was negatively correlated with rosuvastatin in a dose dependent manner. The amount of MMP-9 and pERK decreased significantly by ERK pathway inhibitor PD98059, while ERK expression increased. Rosuvastatin intervention had no obvious effect on the expression levels of MMP-9, ERK and pERK protein. The expression of MMP-9 increased gradually in the conversion of THP-1 cells into foam cells. Rosuvastatin can reverse the expression of MMP-9 protein by suppressing ERK pathway.

Key words: Acute coronary syndrome (ACS), matrix metalloproteinase-9 (MMP-9), Rosuvastatin, oxidized low density lipoprotein (ox-LDL), extracellular-signal-regulated kinases (ERK), pERK.