脂多糖通过NF-κB途径上调大鼠腹膜间皮细胞表达CD40和ICAM-1

目的 观察脂多糖(LPS)作用下大鼠腹膜间皮细胞NF-κB活性及其对CD40和细胞间黏附分子1(ICAM-1)表达的影响.方法 分离及培养大鼠腹膜间皮细胞.LPS不同浓度作用12 h 及LPS (5 μg/ml)作用不同时间点收集细胞;LPS(5 μg/ml)或BAY11-7085(一种IκBα的磷酸化抑制剂)不同浓度(1 μmol/L和5 μmol/L)预处理3 h加LPS,作用3 h后收集细胞;采用RT-PCR方法检测CD40和ICAM-1 mRNA表达.采用蛋白印迹检测NF-κB和磷酸化NF-κB(p-NF-κB)蛋白表达.结果 与常规培养基对照组相比,5 μg/ml LPS组CD40和ICAM-1 mRNA表达显著升高(P<0.05),10 μg/ml LPS组显著高于5 μg/ml LPS作用组(P<0.05).5 μg/ml LPS 作用下,ICAM-1 mRNA表达从1 h开始升高,3 h达到高峰,之后逐渐降低.CD40 mRNA表达在1 h无显著变化,3 h时迅速达到高峰,之后逐渐降低.常规培养的大鼠腹膜间皮细胞结构性表达p-NF-κB蛋白;加入LPS后,p-NF-κB蛋白表达显著增加,其中30 min～1 h表达最强,之后逐渐降低,至2 h仍显著高于常规培养组(P<0.05).加入5 μmol/L BAY11-7085后,LPS诱导的CD40和ICAM-1 mRNA表达显著降低(P<0.05),与正常对照组相比差异无统计学意义. 结论 LPS以时间依赖和浓度依赖模式上调CD40和ICAM-1的表达.NF-κB信号途径参与调节LPS诱导的大鼠腹膜间皮细胞CD40和ICAM-1的表达.

Up-regulation of CD40 and ICAM-1 expression treated with lipopolysaccharide through the activation of NF-κB in rat peritoneal mesothelial cells

Objective To investigate the expression of CD40 and intercellular adhesion molecule-1 (ICAM-1) treated with lipopolysaccharide (LPS) in rat peritoneal mesothelial cells(RPMC) and the role of NF-κB signal transduction pathway. Methods RPMCs were harvested from Sprague-Dawley rat peritoneal cavity and maintained under defined in vitro conditions. The cells were exposed respectively to different concentrations of LPS for 12 h or treated with LPS (5 μg/ml) for different time points. To observe the effect of LPS on the expression of CD40 and ICAM-1, the RPMCs were treated with LPS (5 μg/ml) for different time points. To observe the effect of LPS on the expression of NF-κB and p-NF-κB protein, the RPMCs were treated by LPS or pretreated with BAY11-7085 (5 μmol/L or 1 μmol/L ) for 3 h, then treated with LPS for another 3 h, respectively. Expression of CD40 and ICAM-1 mRNA was examined by RT-PCR. Expression of NF-κB and p-NF-κB protein was detected by Western blot. Results Compared with medium control group, stimulation of RPMCs with 1 μg/ml and 5 μg/ml of LPS resulted in a significant increase in the expression of CD40 and ICAM-1 mRNA(P<0.05). 10 μg/ml of LPS had strongest effect on CD40 and ICAM-1 expression compared with that of 1 μg/ml and 5 μg/ml of LPS. Treatment with 5 μg/ml of LPS resulted in time-dependent increase in the gene level of CD40 and ICAM-1, with the peak at 3 h. However, after that time point, the gene level of them was gradually attenuated. Following treatment with LPS (5 μg/ml), the level of p-NF-κB began to increase at 15 min, gradually reached the peak at 1 h, and then decreased. But the level of p-NF-κB at 2 h was still significantly higher than that of medium control. 5 μmol/L of BAY11-7085 decreased significantly the up-regulation of CD40 and ICAM-1 induced by LPS. Conclusion LPS enhanced the expression of CD40 and ICAM-1 on RPMCs in a concentration-dependent and a time-dependent manner. LPS induced expression of CD40 and ICAM-1 depend on the NF-κB signal transduction pathway.