HDL3抗脂多糖诱导的人脐静脉内皮细胞损伤

目的: 研究高密度脂蛋白3(HDL3)预处理对脂多糖(LPS) 损伤的人脐静脉内皮细胞(HUVECs)的保护作用,并探讨其可能机制。方法: 以不同浓度(50、100和200 μg/L)HDL3预处理HUVECs 18 h,再加入1 mg/L LPS作用6 h。MTT法检测细胞活力,Annexin V/PI双标后流式细胞术检测细胞凋亡,荧光显微镜观察单核细胞与HUVECs黏附,ELISA法检测培养液中VCAM-1含量,细胞免疫组织化学及Western blotting法检测细胞核内NF-κB p65的水平。结果: 与对照组相比,LPS作用后HUVECs增殖活力降低,细胞凋亡及单核细胞黏附显著增加,VCAM-1和核内NF-κB p65水平增加;HDL3预处理可以恢复HUVECs增殖活力,降低细胞凋亡及单核细胞与HUVECs的黏附,减少VCAM-1分泌,并抑制NF-κB p65的核转位,且呈浓度依赖性。结论: HDL3可拮抗LPS 对HUVECs的损伤作用,其机制可能与抑制NF-κB所介导的炎症反应有关。

HDL3 protects human umbilical vein endothelial cells against injury induced by lipopolysaccharide

AIM: To investigate the effects and potential mechanisms of high-density lipoprotein 3(HDL3) preconditioning on lipopolysaccharide (LPS)-induced activation of human umbilical vein endothelial cells (HUVECs).METHODS: HUVECs were pretreated with different concentrations of HDL3 (50 mg/L, 100 mg/L and 200 mg/L) for 18 h and induced by LPS (1.0 mg/L) for another 6 h. Cell viability was measured by MTT assay. AnnexinⅤ/PI double staining was used to measure the cell apoptotic rate by flow cytometry. The numbers of THP-1 cells adherent to HUVECs were observed under fluorescence microscope.Vascular cell adhesion molecule-1(VCAM-1) in culture medium was measured by ELISA. The content of NF-κB p65 in cell nucleus was determined by immunocytochemical staining and Western blotting. RESULTS: Compared with the control cells, LPS decreased the cell survival rates, increased the apoptotic changes and the number of THP-1 cells adherent to HUVECs significantly. Meanwhile, LPS dramatically increased the VCAM-1 expression and NF-κB p65 in cell nucleus. Preincubated with HDL3, the survival rate of HUVECs increased significantly, and LPS-induced increment of apoptosis was suppressed. The number of THP-1 cells adherent to HUVECs declined. The expression of VCAM-1 was inhibited, and NF-κB activation response to LPS was significantly attenuated. CONCLUSION: HDL3 exerts a protective effect against LPS-induced inflammation in HUVECs, which may be partly attributed to the suppression of VCAM-1 secretion as well as inhibition of the activation of NF-κB.