Activation of NF-κB and its regulation on IL-6 expression during LPS-induced liver injury

Objective: To explore the kinetics of the activation of nuclear factor-kappa B (NF-κB) and its regulation of interleukin-6 (IL-6) expression during LPS induced liver injury. Methods: Kunming mice were randomly divided into 4 groups in order to observe the does-effect relationship at 3 h: normal saline solution (control) group, low (1 mg/kg), middle (5 mg/kg), and high (10 mg/kg) LPS-induced groups;6 groups in order to observe the time-effect relationship of 5 mg/kg LPS injection: normal saline solution (control) group, 0.5, 1, 3, 5 and 8 h groups; pyrrolidine dithiocarbamate (PDTC) intervened groups (3 h): normal saline solution (control) group, 5 mg/kg LPS, 200 mg/kg PDTC, and 200 mg/kg PDTC+5 mg/kg LPS groups. NF-κB activities of Kupffer cells were determined with electrophoretic mobility shift assay (EMSA) and expression levels of IL-6 were measured with enzyme-linked immunosorbent assay (ELISA). Results: Does-effect of NF-κB activities in Kupffer cells after LPS injection 3 h: NF-κB activation could be detected in 1 mg/kg LPS group, reached the highest level in 5 mg/kg LPS group, and persisted in 10 mg/kg LPS group; time-course after 5 mg/kg LPS injection: the DNA-binding activity was observable at 0.5 h after LPS injection, increased significantly at 3 h, and persisted for at least 8 h; in addition, antioxidant PDTC could inhibit the activation of NF-κB significantly. The kinetics of IL-6 level in liver tissues during LPS-induced liver injury were that IL-6 level after 3 h of injection increased first and then reduced; the same trend was observed in the time-course on IL-6 level after LPS injection; PDTC could significantly inhibit the release of IL-6. Correlation analyses revealed that IL-6 level was significantly and positively correlated with the activation of NF-κB. Conclusion: NF-κB in Kupffer cells can be activitied during LPS-induced liver injury to some extent, and NF-κB may have some regulation on the expression of IL-6.