Adiponectin inhibits oxidized low density lipoprotein-induced increase in matrix metalloproteinase 9 expression in vascular smooth muscle cells

BACKGROUND: High expression of matrix metalloproteinase 9 (MMP9) during vascular injury and inflammation plays an important role in atherosclerotic plaque formation and rupture. In the process of atherosclerosis, oxidized low-density lipoprotein (oxLDL) upregulates MMP9 in human aortic vascular smooth muscle cells (HA/VSMCs). Adiponectin is an adipose tissuederived hormone that has been shown to exert anti-atherogenic and anti-inflammatory effects. The aim of this study was to investigate the effect of adiponectin on MMP9 expression under pathogenic condition created by oxLDL in HA/VSMCs. METHODS: In this experimental study, HA/VSMC were stimulated with oxLDL alone and in the presence of adiponectin for 24 and 48 h. The expression of MMP9 gene was determined by realtime polymerase chain reaction method. The protein level of this gene was investigated by western blotting technique. RESULTS: An oxLDL increased MMP9 expression 2.16 ± 0.24- and 3.32 ± 0.25-fold after 24 and 48 h, respectively and adiponectin decreased oxLDL-induced MMP9 expression in a timedependent manner. CONCLUSION: These results show that adiponectin changes extracellular matrix by reducing MMP9 mRNA and protein, therefore, may stabilize lesions and reduce atheroma rupture.