Effect of nuclear factor-κB on inflammatory cytokines expression after fluid percussion brain injury in rats

Objective To investigate the expression of nuclear factor-κB (NF-κB) and inflammatory cytokines such as interleukin (IL)-1β,IL-6,tumor necrosis factor (TNF)-α and intercellular adhesion molecule-1 (ICAM-1) following fluid percussion injury in rats,and explore the mechanism.Methods The experimental models were established in 56 rats according to references.The water content and the expression of NF-κB,IL-1β,IL-6,TNF-α and ICAM-1 were measured by using dry-wet measure,and immunohistochemistry on the postoperative time 1,6,12 and 24 h,and 3 and 7 days respectively.Results As compared with SO group,the water content was increased in TBI group from 6 h [(79.11 ± 1.28) ％],reached its peak at 24 h [(82.54 ±1.89)％],lasted to 3rd day [(82.04 ± 1.70)％],and then began to drop at 7th day.Histological observation verified the tendency of brain edema.NF-κB,IL-6,IL-1β,TNF-α and ICAM-1 immunoreactive expression was increased from 6 h,reached its maxmum at 24 h,lasted to 3rd day,and began to drop at 7th day.The linear regression analysis indicated that the expression of NF-κB was positively correlated wih that of IL-1β,IL-6,TNF-α and ICAM-1,and the latter four inflammatory cytokines were positively correlated with brain water content in edematous brain (P ＜ 0.05).Conclusion NF-κB expression is upregulated in fluid percussion injury in rats,which may induce the expression of IL-6,IL-1β,TNF-α and ICAM-1,resulting in secondary brain injury. Key words: Brain injury; Fluid percussion; Nuclear factor-κB; Inflammatory cytokine