Preventive effects of TLR4 monoclonal antibodies on the gut mucosal proinflammatory cytokines (TNF-α,IFN-γ,IL-1β) expression in mice with DSS-induced acute ulcerative colitis

Objective To evaluate the preventive effects of toll like receptor 4 monoclonal antibodies(TLR4mAb)on inflammation,the gut mucosal proinflammatory cytokines(TNF-α,IFN-γ,IL-1β)expression in dextran sulfate sodium(DSS)-induced acute ulcerative colitis(UC)in mice.Methods Thirty male BALB/c mice were randomly assigned into five groups from A to E:normal control group(A),UC model group(B),low dose,moderate dose and large dose intervention group with every time for each(C,D,E).To induce acute intestinal inflammation,group B to group E only drunk 5.0%(wt/wt)DSS solution as drinking water during 7 days' observation,while the normal control drank distilled water freely.Group C,D,E recieved TLR4mAb injection every 48h intraperitoneally at the same time as the start of the DSS exposure.Daily disease activity index(DAI)and histopathological score(HPS)were evaluated.The mRNA expression of TNF-α,IFN-γ,IL-1β were measured by RT-PCR.Results(1)Compared with the control group,the DAI and HPS in the UC group were markedly higher(P0.01).Compared with the UC group,the DAI and HPS in group C to E decreased.(2)Compared with the UC group,the expression of three proinflammatory factors,such as TNF-α,IFN-γ,IL-1β in group C to E decreased in a dose-dependent manner.Conclusions TLR4mAb has preventive effect by down-regulating the mRNA expression of proinflammatory factors,such as TNF-α,IFN-γ,IL-1β et al.