Inhibitory effect of IκBα gene on LPS-induced inflammation in mice / 第二军医大学学报

ABSTRACT

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(P<0.05). 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(P<0.05). 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(P<0.05). Compared with LPS group, LPS+gene transfer group had higher survival rate at 72 and 96 h(P<0.05). 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.