Simvastatin attenuates cardiac isograft ischemia-reperfusion injury by down-regulating CC chemokine receptor-2 expression

Abstract

Accumulating evidence reveals that statins possess direct anti-inflammatory properties through inhibition of proinflammatory cytokine and chemokine secretion in addition to their antioxidant effects, which may contribute to amelioration of ischemia-reperfusion injury. This study tested the hypothesis that perioperative treatment of simvastatin suppresses the cardiac isograft ischemia-reperfusion injury by down-regulation of CC chemokine receptor-2 expression in an inbred rat model of cardiac transplantation. Donor hearts from Lewis rats were heterotopically transplanted to Lewis rat recipients. Recipients were orally treated with simvastatin (1 mg/kg) or vehicle every morning 3 days before the surgery until the harvest day. Rats were killed at 6 hours and at 1, 3, and 7 days after transplantation. Injury was assessed by infarct size measurement, histologic and immunohistochemical examination, and intragraft myeloperoxidase activity assay. Monocyte chemoattractant protein-1 levels in serum and graft were analyzed by enzyme-linked immunosorbent assay, and intragraft CC chemokine receptor-2 expression was measured by quantitative real-time polymerase chain reaction. The infarct size and macrophage infiltration were all significantly reduced in the simvastatin-treated group compared with those of the control group at 1 day after transplantation. Neutrophil accumulation was significantly suppressed until 3 days after transplantation, whereas myeloperoxidase activity had been significantly diminished at 1 day after transplantation. Both monocyte chemoattractant protein-1 concentrations in serum and graft were remarkably decreased at 6 hours after transplantation. Intragraft CC chemokine receptor-2 expression was also down-regulated at 1 day and 3 days after transplantation. Perioperative treatment of simvastatin could suppress the isograft ischemia-reperfusion injury through retarding intragraft monocyte chemoattractant protein-1 accumulation and CC chemokine receptor-2 expression.