Cyclooxygenase-2 expression in atherosclerosis tissues and the effect of celecoxib on proliferation and apoptosis of human vascular smooth muscle cells

Abstract

Objective To investigate the expression of cyclooxygenase-2 (COX-2) in atherosclerosis tissues and the effect of selective COX-2 inhibitor celeboxib on proliferation and apoptosis of human vascular smooth muscle cells (VSMCs).Methods Immunohistochemistry for COX-2 was performed on 22 cases of formalin-fixed,paraffin-embedded human atherosclerosis tissues.Cell growth rate was assessed by methyl thiazol tetrazolium (MTT) assay,and apoptosis was examined by flow cytometry.Results COX-2 protein was detected in 21 of 22 (95％) human atherosclerosis tissues.COX-2 was decreased in VSMCs when treated with celecoxib in vitro.After cells were treated with increasing concentrations of celecoxib (0,10,20,40 and 80 μmol/L) for 24 h,the cell growth rate was 100.00％,90.06％,81.38％,75.41％ and 68.90％ respectively,and the early apoptosis ratio was 0.02％,0.62％,0.92％,1.17％ and 1.63％ respectively.Conclusion COX-2 is highly expressed in human atherosclerosis tissues,and the celecoxib inhibited proliferation and induced apoptosis of VSMCs in a dose-dependent manner. Key words: Cyclooxygenase-2 ; Celecoxib ; Atherosclerosis; Vascular smooth muscle cells; Proliferation ; Apoptosis