内毒素对人巨噬细胞系U937细胞增殖和肿瘤坏死因子-α分泌影响的实验研究

Investigation on the Effect of Endotoxin/lipopolysaccharide on U937 Cells Proliferation and Tumor Necrosis Factor-α Secretion

目的探讨不同浓度的内毒素/脂多糖对人巨噬细胞系U937细胞增殖和肿瘤坏死因子-α分泌能力的影响。方法分别以0.0、2.5、5.0、10.0、20.0、50.0、100.0μg/ml的脂多糖刺激体外6、24、48、72h培养的U937细胞,应用单溶液细胞增殖检测法检测其细胞增殖活力,并计算增殖率;应用酶联免疫吸附实验法检测细胞培养上清肿瘤坏死因子-α的分泌能力。结果实验组与脂多糖为0.0μg/ml时比较,当其浓度为2.5～20.0μg/ml,刺激24、48h时U937细胞增殖活性均明显升高;当脂多糖为50.0、100.0μg/ml时,细胞活力无显著性差异,其中培养24h,脂多糖浓度为2.5μg/ml时,对U937细胞的增殖具有最佳促进作用,增殖率为135.56%。而肿瘤坏死因子-α实验组与脂多糖为0.0μg/ml比较时,培养6h,各浓度组肿瘤坏死因子-α均明显升高,并呈现随培养时间延长而浓度降低的现象,培养6h,脂多糖为5.0μg/ml刺激时,肿瘤坏死因子-α浓度达到峰值为48.2638±5.0098;当其浓度为50.0～100.0μg/ml时能够促进肿瘤坏死因子-α分泌,且也遵循随培养时间延长而浓度降低的规律。结论脂多糖对U937细胞具有一定的增殖作用,且可以激活U937促使其分泌肿瘤坏死因子-α。

Objective To investigate the effect of endotoxin/lipopolysaccharide at different concentrations on U937 cells proliferation and tumor necrosis factor alpha-α secretion.Methods U937 cells were stimulated by lipopolysaccharide at the concentrations of 0.0,2.5,5.0,10.0,20.0,50.0,100.0 μg/ml after 6,24,48,and 72 hours of culture in vitro,respectively,and the proliferation of U937 cells was detected by MTS.The secretion of tumor necrosis factor-α in culture supernatant was detected by ELISA.Results lipopolysaccharide at the concentrations of 2.5,5.0,10.0,20.0 μg/ml could cause significantly higher U937 cells proliferation after 24 and 48 hours of culture than the control group without lipopolysaccharide stimulation.No significant difference of cell proliferation was observed when U937 cells cells were stimulated by lipopolysaccharide at the concentrations of 50.0,100.0 μg/ml.Lipopolysaccharide at a concentration of 2.5 μg/ml promoted U937 cells proliferation most after 24-hour culture,with a proliferation rate of 135.56%.Tumor necrosis factor-α secretion increased in all groups with different concentrations of lipopolysaccharide after 6-hour culture.The longer the culture,the lower the secretion.The peak value of tumor necrosis factor alpha-α secretion was（48.2638±5.0098）when stimulated by lipopolysaccharide at a concentration of 5.0 μg/ml after 6-hour culture.The stimulation of lipopolysaccharide at the concentration of 50.0～100.0 μg/ml could promote tumor necrosis factor-α secretion after 6,24 and 48 hours of culture and longer culture reduced the secretion.Conclusion Lipopolysaccharide could promote the proliferation of U937 cells and activate U937 cells to promote the secretion of tumor necrosis factor-α.