Inhibitory effect of IκBα gene on LPS-induced inflammation in mice

Objective:To construct IκBα vector carrying SAA3 promoter and to observe its effect on NF-κB activity and LPS-induced inflammation,so as to lay a foundation for treatment of sepsis.Methods: Mouse liver cells and kupffer cells were co-cultured and were divided into three groups:control group,LPS group and LPS+ gene transfer group.Twenty-four hours after LPS injection,the levels of AST,ALT,LDH,IL-6 and TNF-α were measured in the supernatants of the each group.For animal experiments:(1) Mice were divided into three groups:control group,LPS group and LPS+gene transfer group(n=10).The levels of TNF-α and IL-6 were measured in the serum and liver tissues 24 hours after intraperitoneal injection of 250ug LPS or saline.(2) Mice were also divided into two groups:LPS group and LPS+gene transfer group(n=21).Mice were injected with 150 μg LPS twice at 0 and 48 h,then the activities of NF-κB and IκBα in the liver were measured at 0,2,24,48,50,72,and 96 h after the first injection.The values at 0 h were taken as control group.(3) Mice were also divided into another two groups:LPS group and LPS+gene transfer group(n=20).The survival rates of animals were observed at 0,2,24,48,50,72,and 96 h after injection of 350 μg LPS.Results: Compared with LPS group,the levels of AST,LDH,TNF-α and IL-6 in the culture supernatants of LPS+gene transfer group were decreased,but were still higher than those in the control group(P0.05).Compared with LPS group,the levels of TNF-α and IL-6 in the liver tissues and sera of LPS+gene transfer group were significantly decreased(P0.05).Compared with LPS group,the activity of NF-κB in the liver tissues of LPS+gene transfer group were decreased,but was still significantly higher than that of the control group(P0.05).Compared with LPS group,LPS+gene transfer group had higher survival rate at 72 and 96 h(P0.05).Conclusion: IκBα gene can be expressed in the liver with SAA3 promoter,and transfection of IκBα can effectively inhibit endotoxin-induced liver and general inflammation.