植物血凝素样氧化型低密度脂蛋白受体介导氧化型低密度脂蛋白对内皮祖细胞存活和功能的影响  

Effects of Oxidized Low-density Lipoprotein on Endothelial Progenitor Cells Survival and Activity Mediated by Lectin-like Oxidized Low Density Lipoprotein Receptor

作　　者：马凤霞[1] 任倩[1] 韩忠朝[1] 

机构地区：[1]中国医学科学院北京协和医学院血液学研究所血液病医院实验血液学国家重点实验室,天津300020

出　　处：《中国医学科学院学报》2007年第3期336-341,I0005,共7页Acta Academiae Medicinae Sinicae

基　　金：国家高技术研究发展计划项目(863项目)(2003AA205060)~~

摘　　要：目的研究植物血凝素样氧化型低密度脂蛋白受体(LOX-1)是否介导氧化型低密度脂蛋白(oxLDL)对内皮祖细胞(EPC)的存活及功能产生影响。方法分选脐血CD34+细胞,培养于内皮细胞生长培养基(EGM-2)中。培养14d后,部分EPC与10、25、50μg/ml的oxLDL孵育48h;部分EPC先与LOX-1单克隆抗体(LOX-1 mAb)预处理24h,再与50μg/ml oxLDL孵育48h;对照组不作处理。检测EPC存活率及EPC迁移、黏附和管状结构形成能力,并检测LOX-1的蛋白及mRNA表达。结果oxLDL浓度为25和50μg/ml时,凋亡率分别为(15.8±1.0)%和(18.8±2.0)%,显著高于对照组的(9.0±1.2)%(P<0.05);迁移率分别为(5.7±1.0)%和(5.1±0.8)%,显著低于对照组的(9.5±0.8)%,(P<0.05);黏附细胞数分别为(33±2)和(30±3)个,显著少于对照组的(37±5)个(P<0.05);形成的管状结构分别为(2.9±0.5)和(1.8±0.5)mm,显著短于对照组的(5.0±0.6)mm(P<0.05)。OxLDL可增加LOX-1 mRNA及蛋白的表达,oxLDL浓度为50μg/ml时,LOX-1 mRNA表达由100%增加为(174±39)%,蛋白表达由100%增加为(172±8)%。OxLDL的上述作用能被LOX-1mAb所阻断。结论OxLDL可降低EPC存活,抑制EPC功能,其作用是由LOX-1介导的。Objective To investigate whether oxidized low-density lipoprotein （oxLDL） affects the survival and activity of endothelial progenitor cell （ EPC ） and whether the effects are mediated by lectin-like oxidized low-density lipoprotein receptor （ LOX-1 ）. Methods CD34^＋ cells isolated from human umbilical blood were cultured in endothelial cell growth medium-2 （EGM-2）. After 14 days of culture, some EPCs were stimulated with 10, 25, 50 μg/ml of oxLDL for 48 hours; some were preincubated with LOX-1 mAb, a blocking antibody of LOX-1, for 24 hours, then exposed to 50 μg/ml oxLDL for 48 hours; others without any further treat- ment were used as control. The survival of EPC and the ability of adhesion, migration, and tube formation were examined. The levels of LDX-1 protein and mR.NA expression were also assayed. Results Incubation with oxLDL at concentrations of 25 μg/ml or higher resulted in a close-dependent increase of EPC apoptosis [25 μg/ml： （15.8 ± 1.0） %, 50 μg/ml ： （ 18. 8± 2. 0） % versus control ： （9. 0 ± 1.2） % ; P 〈 0. 05 ]. Treated with oxLDL led to a significantly reduced migratory rate [25 μg/ml： （5.7 ±1.0）%, 50 μg/ml： （5. 1 ±0.8）% versus control： （9.5 ＋ 0. 8） % ; P 〈 0. 05 ]. EPC treated with oxLDL showed a dose-dependent reduction of adhesion to fibronectin （25 μg/ml： 33 ±2, 50 lμg/ml： 30±3 versus control： 37 ±5; P 〈0. 05）. Treatment with oxLDL impaired the in vitro vasculogenesis ability of EPCs. The total length of the tube structures in each photograph was decreased [ 25 μg/ ml： （2.9±0.5） mm, 50 μg/ml： （1.8±0.5） mm versus control： （5.0±0.6） ram; P〈0.05]. The tube structure was severely disrupted, resulting in an incomplete and sparse tube network. However, all the detrimental effects on EPC were attenuated by pretreatment of EPC with LDX-1 mAb. In addition, Western blot analysis revealed that oxLDL increased LDX-1 protein expression from 100% to （172 ±8）% at a dose of 50 μg/ml. Furthe

关 键 词：氧化型低密度脂蛋白 内皮祖细胞 植物血凝素样氧化型低密度脂蛋白受体 

分 类 号：R543.5[医药卫生—心血管疾病]