内毒素诱导退变人椎间盘髓核细胞凋亡

摘要

Objective To find the relationship between nuclear factor kappB (NF-κB) activation and cell apoptosis.Methods Degenerative human nucleus pulposus cells were cultured in vitro.Useing CCK-8 to observe the proliferative effect of LPS on the nucleus pulposus cells in vitro, in the concentration of 100, 200, 500 and 1 000 μg/mL and choose the most apropriate concentration.The experiment was divided into blank control group, LPS(500 μg/mL)groups, and NF-κB inhibitor(BAY11-7082)plus LPS(500 μg/mL)group,Annexin V-FITC/PI flow cytometry and Hoechest33258 staining was used to analyze apoptosis.The expression of cleaved caspase-3,PARP,P65,P-P65 proteins were detected by Western blot respectively.Results When LPS was 500 μg/mL, the cell vitality was obviously declined.Compared with the blank control group, cell apoptosis rate of the LPS group is increasing (P<0.05), and the expression of P-P65,cleaved caspase-3, cleaved PARP were alsohigher (P< 0.05).Compared with the LPS group, cell apoptosis rate of the NF-κB inhibitor plus LPS group is significantly lower (P<0.05) and the expression of P-P65,cleaved caspase-3,cleaved PARP were also lower (P< 0.05).Conclusions NF-κB signaling pathway may be associated with the nucleus pulposus cell apoptosis in disc degeneration.%目的 观察内毒素(LPS)刺激退变人椎间盘髓核细胞前后,核因子kappB(NF-κB)的活化与细胞凋亡的相互关系.方法 体外培养退变的人椎间盘髓核细胞,采用CCK-8法测定LPS在不同浓度下(100、200、500和1 000 μg/mL)对髓核细胞增殖影响,并筛选合适的刺激浓度;设立空白对照组,单纯LPS(500 μg/mL)刺激组,NF-κB 抑制剂(BAY11-7082)+LPS(500 μg/mL)刺激组,以Hochest33258染色以及AnnexinV-PI双标法检测细胞凋亡;Western blot检测凋亡相关蛋白caspase-3、PARP、NF-κB 结合蛋白P65以及磷酸化P-P65的表达.结果 CCK-8实验结果 显示当LPS浓度为500 μg/mL能明显降低细胞的活力.与空白对照组相比,单纯LPS刺激组细胞凋亡率上升(P<0.05),P-P65表达明显增加,其凋亡蛋白活化型caspase-3和PARP降解产物表达也增高(P<0.05).而与单纯LPS刺激组相比,NF-κB 抑制剂+LPS刺激组细胞凋亡率下降(P<0.05),P-P65表达明显降低,其凋亡蛋白活化型caspase-3和PARP降解产物表达也降低(P<0.05).结论 NF-κB信号通路可能与椎间盘退变时髓核细胞凋亡的发生密切相关,值得进一步研究.