Comparison on monocyte expression of Toll-like receptor 4 in patients undergoing PCI (Percutaneous Coronary Intervention) and patients with acute myocardial infarction

Abstract

Evidence from several lines of studies suggests that Toll-like receptor 4 (TLR4) is involved in formation and progression of atherosclerotics plaques. Its activity on the surface of monocytes leads to production of pro-inflammatory cytokines. Percutaneous Coronary Intervention (PCI) and medical reperfusion therapies can trigger immune response. In this study we aimed at assessing the role of TLR4 in patients with ischemic heart disease (IHD). We explored the effects of medical and non-medical interventions on TLR4.MethodsBlood samples were taken before any intervention. It was repeated two hours and four hours after treatments. Control group was composed of healthy volunteers. Patients were divided into 4 groups. The expression of hTLR4 on the surface of CD14+ monocytes and the serum levels of TNF- and IL-1 were measured using flowcytometry and ELISA.ResultsPatients with more severe coronary stenosis exhibited enhanced expression of TLR4+/CD14+ monocytes (p<0.01). In addition, significant correlations were seen between percentage stenosis diameter and monocyte expression of hTLR4 as well as TNF-. By comparing the frequency of circulating TLR4+/CD14+ monocytes at different time points, PCI procedure up regulated the monocyte expression of TLR4 (p<0.05). Hydrocortisone significantly reduced monocyte expression of TLR4 in treated group (p<0.01). In addition, it had a significant effect on reduction of serum concentrations of TNF-and IL-1 in patient group in a time dependent manner (p<0.01). patients under went medical reperfusion therapy showed enjaced expression of TLR4 and serum levels of cytokines.ConclusionThese findings suggest that TLR4 monocyte expression and sensitization is involved in progression and deterioration of atherosclerosis. PCI and medical reperfusion therapy are positively associated with increase in the monocyte expression of TLR4.Hydrocortisone was able to reduce the monocytes expression of hTLR4 and its related pro-inflammatory cytokines and thus can decrease inflammatory responses following PCI.