Change And Value Of Serum Soluble Lectin-Like Oxidized Low-Density Lipoprotein Receptor-1 In Acute Coronary Syndrome

Objective:In recent years, more and more evidence show that oxidized low-density lipoprotein (ox-LDL) is an independent risk factor for coronary heart disease and it is involved in the very early critical steps of acute coronary syndrome(ACS). The lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is the major receptor for ox-LDL. LOX-1 appears to play crucial roles in the pathogenesis of atherosclerotic plague rupture and ACS onset. Many factors may upregulate the expression of LOX-1, including hyperlipemia, diabetes, hypertension. LOX-1 can be cleaved at the juxtamembrane region, most likely by serine proteases, and secreted in a soluble form (sLOX-1). Circulating levels of sLOX-1 were increased in ACS. sLOX-1 is a useful biomarker for early diagnosis of ACS. In this study, We investigated the change and value of serum sLOX-1 in patients with ACS and analyzed the association of sLOX-1 levels with 8-isoprostane levels, high sensitive C-reactive protein(hs-CRP) and the numbers of coronary artery stenosis.Methods:96 patients were enrolled in this study, diagnoses were made according to The Seventh Edition of Internal Medicine standard about ACS, including 78 ACS patients (UA group: 30, AMI group: 48) and 18 patients without coronary artery disease by coronary angiography (CAG) as control group. The age were between 51-70 years old, the average age was 60.21±7.98 years old. All of them had CAG, the ACS patients who mean reduction vascular lumen at least reach 50% were separated into 3 groups: single coronary artery stenosis group(29), two coronary arteries stenosis group(17) and three coronary arteries stenosis group(32). The levels of serum sLOX-1, hs-CRP and 8-isoprostane were measured by ELISA. Results:1.The serum levels of sLOX-1 in AMI group (13.31±3.10ng/mL) were higher than that in UA group (8.22±1.53ng/mL) and control group (3.46±0.71 ng/mL) (P﹤0.05).The serum levels of 8-isoprostane in patients with AMI (1.54±0.30ng/mL) were higher than that in the UA group (0.53±0.10ng/mL) and the control group (0.24±0.05ng/mL) (P﹤0.05). The serum levels of hs-CRP in AMI group (15.96±2.08mg/L) were obviously higher than that in UA group (9.28±1.60mg/L) and control group (4.06±1.19mg/L()P﹤0.05). Compared with the control group , the serum levels of three indicators were higher than those in UA group (P﹤0.05).2.The serum levels of sLOX-1 showed a positive correlation to the serum levels of hs-CRP (r=0.855, P=0.001) and the linear regression equation was y=0.695x+1.463(y: The serum levels of sLOX-1; x: the serum levels of hs-CRP). The serum levels of sLOX-1 showed a positive correlation to the serum levels of 8-isoprostane(r=0.830, P=0.000)and the linear regression equation was y=6.281x+3.629(y: the serum levels of sLOX-1; x: the serum levels of 8-isoprostane).3.The serum levels of sLOX-1 in three coronary arteries stenosis group (13.59±1.76ng/mL)were obviously higher than other groups(P﹤0.05). The serum levels of sLOX-1 in two coronary arteries stenosis group (9.02±1.08ng/mL)were higher than the single coronary artery stenosis group(5.89±1.14ng/mL)(P﹤0.05). Compared with the control group , the serum levels of 8-isoprostane and hs-CRP in three coronary arteries stenosis group, two coronary arteries stenosis group and the single coronary artery stenosis group were increased(P﹤0.05). But one-way ANOVA shows that no statistic differences among these three groups(P>0.05).Conclusions:1.The serum levels of sLOX-1 are upregulated during ACS. sLOX-1 may be a biomarker to reflect the inflammatory condition.2.Inflammation and oxidative stress are involved in the cleavage of LOX-1.