The Role Of Toll-like Receptors On Mechanism Of IBD

PARTâ… The expression of TLR2,TLR4,TLR9 in rats with colitisObjective To investigate the expression of TLR2,TLR4 and TLR9 in the colon mucosa of rats with colitis.Methods The rat colitis model was induced by the combined enema of trinitrobenzene sulphonic acids (TNBS) and ethanol. The disease activity index (DAI),colon mucosa damage index (CMDI) and histological change of the rats were observed and evaluated. The superoxide dimutase (SOD) and activity of myeloperoxidase (MPO) were measured by biochemical method. The expression of TLR2,TLR4 and TLR9 were detected by immunohistochemistry, and the mRNA were detected by RT-PCR.Results As compared with the normal group, the DAI, CMDI, and the activity of MPO in the colon tissues of the rats in the model group was significantly increased(all P<0.01), while the activity of SOD was decreased(P<0.01). The expression of TLR2,TLR4 and TLR9 in the rat colon mucosa were significantly increased(all P<0.01), and the mRNA were significantly increased (all P<0.01). The expression of TLR2,TLR4 and TLR9 in rat colon mucosa were positively related with MPO and SOD(all P<0.05).Conclusion The expression of TLR2,TLR4 and TLR9 were significantly increased in the colon mucosa of rats induced by TNBS and ethanol. This may be related with the autoimmune impair of the gut. PARTâ…¡Effects of different probiotics on TLR2,TLR4 and TLR9 in rats with colitisObjective To investigate the effect of different probiotics on the expression of TLR2,TLR4 and TLR9 in the colon mucosa of rats with colitis.Methods The rat colitis model was induced by the combined enema of trinitrobenzene sulphonic acids(TNBS) and ethanol. The experimental animals were randomly divided into five group: normal group, model group, Meichang'an (praeparatum of viable organism of enterococci and bacillus subtilis)group, sulfasalazine(SASP)group and Lizhuchangle (praeparatum of viable organism of bacillus bifidus)group. The Saline, Meichang'an , SASP and Lizhuchangle were administered by gastric irrigation daily, Respectively, from 24 hours after the establishment of model to the end of experiment. The disease activity index (DAI),colon mucosa damage index (CMDI) and histological change of the rats were observed and evaluated. The superoxide dimutase (SOD) and activity of myeloperoxidase (MPO) were measured by biochemical method. The expression of Toll-like receptor 2(TLR2),Toll-like receptor 4(TLR4) and Toll-like receptor 9(TLR9) were detected by immunohistochemistry, and their mRNA were detected by RT-PCR.Results As compared with the model group, the DAI, CMDI, histological change and the activity of MPO in the colon tissues of the rats in the Meichang'an group and SASP group were significantly decreased(all P<0.01), while the activity of SOD was significantly increased(all P<0.01). The expression of TLR2,TLR4,TLR9 in the rat colon mucosa were significantly increased , either their mRNA(all P<0.05). And compared with the model group, all these items in Lizhuchangle group didn't change significantly. The expression of TLR2,TLR4 and TLR9 in rat colon mucosa was positively related with MPO and SOD(MPO: r = 0.515, 0.386, 0.537; all P< 0.01; SOD: r =-0.523, -0.474, -0.566; all P< 0.01).Conclusion Meichang'an and SASP has protective effect against rat model with colitis, and their mechanism may be related with the inhibition of TLR2,TLR4 and TLR9.