摘要目的 探讨人α-防御素(human α-defensin,HNP)-1对人内皮细胞氧化低密度脂蛋白(low density lipoprotein,LDL)的影响及其可能机制.方法 实验设HNP-1转染组(HNP-1转染的内皮细胞ECV304),siRNA干扰组(siRNA干扰抑制HNP-1表达的ECV304)和HNP-1刺激组(10 μg/mlHNP-1刺激的ECV304),并分别设有正常ECV304作为对照组,均经LDL处理3h后检测脂质氧化产物丙二醛(M DA)、蛋白氧化产物PCO(protein carbonyl,PGO)的生成量.分别采用流式细胞仪、荧光显微镜检测经LDL、脂多糖(LPS)、HNP-1预处理的ECV304(分别为LDL组、LPS组、HNP-1刺激组)和过表达HNP-1的ECV304(HNP-1转染组)中氧自由基的生成量,另设正常ECV304作为对照组.结果 (1) MDA和PCO生成量检测结果:HNP-1刺激组、HNP-1转染组MDA生成量均明显高于其相应的对照组[分别为(14.49±1.10)比(9.47±1.18) nmol/mg蛋白和(4.21 ±0.03)比(3.15±0.02)nmol/mg蛋白,P均＜0.05].siRNA干扰组MDA生成量则明显低于其对照组[(3.76±0.48)比(4.54 ±0.28) nmol/mg蛋白,P＜0.05].HNP-1转染组PCO生成量明显高于对照组和siRNA干扰组(P均＜0.C5),且siRNA干扰组较对照组低,但差异无统计学意义.(2)氧自由基水平检测结果:HNP-1刺激组和HNP-1转染组ECV304内氧自由基水平均较LDL组、LPS组及对照组高(P均＜0.05).结论 HNP-1可增强人内皮细胞ECV304氧化LDL的能力,机制可能与提高氧自由基的表达水平有关.

abstractsObjective To explore the role and potential mechanism of human α-defensin 1 (HNP-1) on low-density lipoprotein (LDL) oxidation ability of human endothenial cells (EVC304).Methods Post incubation with LDL for 3 h,the malondiadehyde (MDA) and protein carbonyl (PCO) were detected in untreated ECV304 (control) and in HNP-1 transfected ECV304 in the presence and absence of siRNA against HNP-1.Flow cytometry and fluorescence microscopy were used to detect the generation of oxygen free radical in the ECV304 which have been pretreated by LDL,LPS and HNP-1,respectively.Result Compared with control group,MDA level was significantly increased in HNP-1 transfected[(4.21 ± 0.03) vs.(3.15 ± 0.02) nmol/mg · pro] or in HNP-1stimulated ECV304 cells [(14.49 ± 1.10) vs.(9.47 ± 1.18) nmol/mg · pro],which could be significantly downregulated by siRNA [(3.76 ± 0.48) vs.(4.54 ± 0.28) nmol/mg · pro,all P ＜ 0.05].PCO was also significantly increased in HNP-1 transfected ECV304 cells.The levels of free radical were significantly increased in HNP-1 transfected or HNP-1 stimulated ECV304 cells.Conclusion HNP-1 can enhance the LDL oxidation ability of human endothelial cells via promoting the generation of free radicals.