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

Introduction: 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. Methods: 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. Results: 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. Conclusion: 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.