内毒素对人外周血单个核细胞向血管内皮细胞分化的影响

目的  观察不同浓度脂多糖（LPS）对外周血单个核细胞（PBMCs）体外向血管内皮细胞分化的影响。方法  取健康成人PBMCs，以血管内皮生长因子（VEGF）和碱性成纤维细胞生长因子（bFGF）进行诱导，加入不同浓度的LPS干预处理，倒置相差显微镜下观察PBMCs的形态改变，流式细胞术检测细胞表达CD31和血管假性血友病相关因子（vWF）。结果  体外培养的PBMCs呈贴壁生长，诱导培养后，经历小圆形→梭形→扁平细胞的演变过程。与对照组比较，0.01μg/ml LPS组最后形成的梭形细胞数增加，随着LPS浓度进一步增加，细胞数呈递减趋势。流式细胞术检测结果显示，与对照组比较，0.01μg/ml LPS组，CD31/vWF双阳性细胞数明显增加，差异有统计学意义（P <0.05）；0.10μg/ml LPS组CD31/vWF双阳性细胞数无明显改变（P >0.05）；随着LPS浓度进一步增加，CD31/vWF双阳性细胞数呈减少趋势，差异有统计学意义（P <0.05）。结论  0.01μg/ml LPS能最大限度地促进PBMCs向内皮细胞分化，随着LPS浓度增加，PBMCs分化呈抑制作用，这可能与LPS激活核转录因子-κB（NF-κB）的数量及亚单位不同有关。

Effect of endotoxin on activity of vascular endothelial cells differentiated from peripheral blood mononuclear cells

Objective To investigate the effects of lipopolysaccharide (LPS) on the in vitro differentiation of peripheral blood mononuclear cells (PBMCs) to vascular endothelial cells (VECs). Methods PBMCs from healthy volunteers were induced by VEGF and bFGF, and exposed to different concentrations of LPS. The inverted phase contrast microscope was used to observe the morphological changes of the cells. The immunofluorescence staining of CD31 and vWF was examined with flow cytometer. Results The morphological characteristics of the cells were observed at different passages under inverted phase contrast microscope. Compared with the control group, the number of positive cells in 0.01 μg/ml LPS-intervented group significantly increased (P < 0.05), while that in the 0.10 μg/ml LPS-intervented group had no significant difference (P > 0.05). The number of positive cells in 1.00-10.00 μg/ml LPS-intervented groups remarkably reduced compared to that in the control group (P < 0.05). Conclusions LPS at a concentration of 0.01 μg/ml can enhance differentiation of PBMCs. However, with the concentration of LPS increasing, the differentiation of PBMCs is inhibited, which may be related to activation of different number and subunits of NF-κB by different concentrations of LPS.