Effect of Atorvastatin on TLR4 Expression on Monocytes in Patients with Acute Coronary Syndromes

Objective Activation of Toll-like receptor4 (TLR4) may involve in progression and instability of atherosclerotic plaque. We hypothesized that anti-inflammatory effects of statins are mediated by regulation of TLR4 expression. Design and methods 121 persons (22 normal persons, 17 patients with stable angina and 82 patients with ACS) were investigated. 41patients with ACS were randomized to either atorvastatin 10 mg/d or atorvastatin 40 mg/d in addition to their routine anti-anginal treatment. Serum level of HsCRP, blood lipids, and TLR4 expression on CD14+ monocytes were measured before and after one month treatment. TLR4 expression on CD14+ monocytes was quantified via flow-cytometry. Results hsCRP and TLR4 expression on CD14+ monocytes in patients with ACS were higher than patients with stable angina (p<0.05) and normal persons (p<0.05). Serum hsCRP and TLR4 expression on CD4+ monocytes in patients with ACS were decreased after one month treatment with atorvastatin (p<0.05). The effect of atorvastatin 40 mg/d on TLR4 expression was more effective than that of atorvastatin 10 mg/d (p<0.05). Conclusions Our study indicates that part of the anti-inflammatory effect of atorvastatin may be mediated by down-regulating the expression of TLR4.