中国医学科学院学报

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中国医学科学院学报

中国医学科学院学报 ›› 2007, Vol. 29 ›› Issue (3): 336-341.

• 论著 • 上一篇    下一篇

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

马凤霞,任 倩,韩忠朝   

  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
  • 收稿日期:2006-07-20 修回日期:1900-01-01 出版日期:2007-06-30 发布日期:2007-06-30
  • 通讯作者: 韩忠朝

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

MA Feng-xia, REN Qian, HAN Zhong-chao   

  1. State Key Laboratory of Experimental Hematology, Hospital of Blood Disease, Institute of Hematology, CAMS and PUMC, Tianjin 300020, China
  • Received:2006-07-20 Revised:1900-01-01 Online:2007-06-30 Published:2007-06-30
  • Contact: HAN Zhong-chao

摘要: 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14 d 后,部分EPC与10、25、50 μg/ml的oxLDL孵育48 h;部分EPC先与LOX-1单克隆抗体(LOX-1 mAb)预处理24 h,再与50 μg/ml oxLDL孵育48 h;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50 μg/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50 μg/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。

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

Abstract: ABSTRACT: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 treatment were used as control. The survival of EPC and the ability of adhesion, migration, and tube formation were examined. The levels of LOX-1 protein and mRNA expression were also assayed. Results Incubation with oxLDL at concentrations of 25 μg/ml or higher resulted in a dose-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 μg/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) mm; 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 LOX-1 mAb. In addition, Western blot analysis revealed that oxLDL increased LOX-1 protein expression from 100% to (172±8)% at a dose of 50 μg/ml. Furthermore, oxLDL caused an increase in LOX-1 mRNA expression from 100% to (174±39)% at a dose of 50 μg/ml. Conclusion OxLDL can directly inhibit EPC survival and activity and these effects are mediated by its receptor, LOX-1.

Key words: oxidized low density lipoprotein, endotdelial procenitor cell, lectin-like oxidized low density lipoprotein receptor