Objective To observe the expression of Matrix Metalloproteinase-9 (MMP-9) induced by LTB4 in THP-1 macrophages and to explore its significance in patients with ACS.Methods Differentiated THP-1 macrophages was stimulated with LTB4 in different concentration(10-10～10-7mol/L) and for different time(0,6,12,24 and 48 hours).RT-PCR was used to measure the expression of MMP-9 mRNA and Gelatin Zymography was used to evaluate the activity of MMP-9.Serum LTB4,MMP-9 and CRP was measured by Enzyme-linked immunosorbent assay(ELISA) in 115 patients with ACS and 105 healthy people(control group).Results LTB4(10-10～10-7mol/L) upregulated MMP-9 mRNA expression in dose-and time-dependent manner and also enhanced MMP-9 activity.Serum LTB4 was significant higher in patients with acute myocardial infarction(AMI)and unstable angina pectoris(UAP) than that in control group(112.77±22.59pg/mL,86.94±14.81pg/mL and 40.5±8.85pg/mL,respectively.P<0.01).Besides,LTB4 was positive correlated with MMP-9(r=0.875,P<0.001)and CRP(r=0.641,P<0.01).Conclusions LTB4 significantly upregulates MMP-9 expression and enhances its activity.Furthermore,levels of LTB4 and MMP9 are elevated in ACS.LTB4 and MMP-9 may play an important role in atherosclerosis by combining to form an inflammatory network and thus may contribute to the attack of ACS and serve as a potential treating target.
