Up-regulation of CD40 and ICAM-1 expression treated with lipopolysaccharide through the activation of NF-κB in rat peritoneal mesothelial cells / 中华微生物学和免疫学杂志

ABSTRACT

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.