Evaluation of MMP-9, IL-6, TNF-α levels and peripheral blood mononuclear cells genes expression of MMP-9 and TIMP-1 in Iranian patients with coronary artery disease

Coronary artery disease (CAD) is the main cause of death and is characterized by atherosclerosis in coronary arteries. Inflammation plays a crucial role in the progression and development of atherosclerosis.

The present study consisted of 132 Iranian individuals who underwent coronary angiography, 65 patients with CAD, and 67 controls. The matrix metalloproteinase-9 (MMP-9), TNF-α, IL-6, and vitamin D serum levels were measured by the ELISA technique. The gene expression of MMP-9 and tissue inhibitors of metalloproteinase (TIMP-1) was estimated by real-time PCR assay.

A considerable increase in levels and PBMC gene expression of MMP-9 and serum levels of IL-6 and TNF-α were found in CAD patients compared with controls. A significant decrease was detected in vitamin D levels of CAD patients in comparison with controls. A considerable direct correlation was found between MMP-9 levels and MMP-9 and TIMP1 gene expression in CAD patients. MMP-9 levels positively correlated with LDL-C in CAD patients. The correlation between TIMP1 gene expression and IL-6 levels was also negatively significant. There were positive correlations between MMP-9 levels with IL-6 and TNF-α serum levels in CAD patients.

This study showed that the interaction between MMPs, TIMP1, and cytokines could play a role in the pathogenesis of atherosclerosis. The present study suggested that high levels of TNF-α and IL-6 and vitamin D deficiency in our studied patients could disturb the MMP-9/TIMP-1 balance and lipid metabolism, leading to plaque formation/ rupture in predisposed CAD patients.