The effects of NAC on NF-κB activation and cytokines expression in PBMC of rats after severe burns

Objectives:To study the alterations of NF-κB activation in PBMC, in order to clarify the signal transcription of NF-κB concerned in the mechanism of inflammatory reaction in severe burns. To evaluate the alterations of expression of NF-κB dependent proinflammatory cytokines mRNA. Thereby, to observe the regulating effects of NAC on NF-κB, and verify the medial effects of upstream signal molecules on cytokines expression. Methods:Sprague Dawley rats were randomly assigned to each group. A 30% TBSA full-thickness scald was performed by immersing in 100℃ water for 12 seconds. PBMC were isolated at different time point after scalding. From isolated PBMC, the total RNA was isolated and the nuclear protein purified by Trizol reagents. The NF-κB proteins were measured through EMSA. Message RNA expression of proinflammatory cytokines and Th2 cytokines were assayed by RT-PCR. Results:Lots of NF-κB proteins were sequester in nucleus in all burn groups. mRNA expression of proinflammatory cytokines were also enhanced and related to the activity of NF-κB protein in nucleus. NAC could decrease the activity of NF-κB protein in nucleus. NAC had also significantly inhibitory effects on the production of proinflammatory cytokines. However, all of Th2 cytokines measured in this study were enhanced too. Conclusions:NF-κB might be the second signal molecule from cytosol to nucleus and mediate the proinflammatory cytokines transcription in PBMC after burns. In signal transduction levels, enhancing scavengers of oxygen free radicals in PBMC may modulate the activity of NF-κB which mediate the expression of proinflammtory cytokines.