Association of Lipoprotein-Associated Phospholipase A2 with Characteristics of Vulnerable Coronary Atherosclerotic Plaques

PURPOSE: Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an inflammatory enzyme expressed in atherosclerotic plaques. We investigated the association of circulating Lp-PLA2 with characteristics of vulnerable coronary atherosclerotic plaques. MATERIALS AND METHODS: We recruited 113 patients with either unstable angina (UA, n=59) and stable angina (SA, n=54) by coronary angiography. Thirty-six healthy subjects served as controls. Intravascular ultrasound (IVUS) was used to evaluate the characteristics of coronary atherosclerotic plaque, and serum Lp-PLA2 concentration was measured as well. RESULTS: Lp-PLA2 concentration was significantly higher in both UA and SA patients [(396+/-36) microg/L and (321+/-39) microg/L, respectively] compared with the controls [(127+/-49) microg/L, p<0.01], and higher in UA than SA group. IVUS findings showed that remodeling index (RI) (0.91+/-0.15 vs. 0.85+/-0.11, p=0.005) and eccentricity index (EI) (0.73+/-0.16 vs. 0.65+/-0.22, p=0.039) were larger in UA than in SA group, and fibrous caps were thicker in SA than UA group [(0.91+/-0.23) mm vs. (0.63+/-0.21) mm, p=0.032]. Moreover, Lp-PLA2 correlated positively with EI (r=0.439, p<0.01) and RI (r=0.592, p<0.05) in UA group. There was an inverse relationship between Lp-PLA2 and fibrous cap thickness in both UA (r=-0.587, p<0.001) and SA (r=-0.318, p<0.05) groups. The independent risk factors in UA group were Lp-PLA2 (OR=1.055, 95% CI: 1.03-1.08, p=0.013), LDL-cholesterol (OR=0.032, 95% CI: 0.00-0.05, p=0.041) and fibrous cap thickness (OR=0.008, 95% CI: 0.00-0.45, p=0.019). Lp-PLA2 was strongly associated with both EI and fibrous cap thickness in both groups. CONCLUSION: Serum level of Lp-PLA2 is associated with both eccentricity index and fibrous cap thickness in both UA and SA groups. Elevated levels of circulating Lp-PLA2 might to be a strong risk factor and more serious for unstable angina than stable angina.

siRNA inhibits efgl7 expression in human endothelial cell line HUVEC / 中华心血管病杂志

<p><b>OBJECTIVE</b>To evaluate the effects of small interference RNA (siRNA) on epidermal growth factor-like domain 7 (egfl7) gene expression in human endothelial cell line HUVEC.</p><p><b>METHODS</b>siRNA targeting egfl7 (siRNA1, siRNA2, siRNA3 and siRNA4) was constructed through online design of Amnion company and transfected into human endothelial cell line HUVEC with lipofectamine. The nontransfected cells and cells treated with control siRNA were taken as controls. At 24, 48 and 72 hours post various interventions, cell viability was determined by MTS method as well as LDH and ATP releasing tests. egfl7 expressions at protein and mRNA levels were detected by Western blot and RT-PCR respectively.</p><p><b>RESULTS</b>Cell survival rate, LDH and ATP release were significantly reduced in siRNA treated cells compared to control cells (P < 0.05). Similarly, egfl7 expression at protein and mRNA levels was also significantly reduced in siRNA treated cells (P < 0.01), especially in siRNA1 treated cells.</p><p><b>CONCLUSION</b>siRNA inhibited egfl7 gene expression and cell survival in HUVEC.</p>