Effect Of Schistosome Ova On Intestinal Epithelial Tight Junctions And NOD2 During TNBS-induced Colitis

Part 1 Effect of schistosome ova on intestinal epithelial tight junctions during TNBS-induced colitisObjective To observe the possible effect of schistosome ova on intestinal epithelial tight junctions ZO-1,Occludin and to explore the mechanism.Method Fifty mice are randomly divided into three groups,that is control group(group A,n=10),TNBS plus normal saline(NS) group(group B,n=20),TNBS plus schistosome ova group(group C,n=20).Mice of group C were exposed to 10000 freeze-killed schistosome ova by intraperitoneal injection at day 14 and day 3 before colitis induction.At the same time,mice of group B were exposed to 1ml NS by intraperitoneal injection.Each mice of group B and C were challenged with 3mg trinitrobenzesulfonic acid(TNBS) to induce colitis.All mice were killed 7-day after colitis induction and assessed with following variables including mortality, pathological change with H-E staining of colon(using Ameho -criteria.),the transcription levels of ZO-1 and Occludin in colon tissues are measured by Real-time PCR,the expressions and distribution of ZO-1 and Occludin proteins are measured by western blotting and immunohistochemistry.Results Compared with group B,the colonic inflammation of group C is alleviated,using Ameho -criteria,group B is 4.21±0.4,group C is 1.74±0.1(P＜0.05);the transcription levels of ZO-1,Occludin in TNBS-induced mice decreased compared with normal controls and schistosome ova-treated mice(P＜0.05);when compared with TNBS-induced mice,schistosome ova-treated ones experienced a significantly reduction of the alteration of ZO-1, Occludin proteins expressions and localization(P＜0.05).Conclusion Our results clearly show that schistosome ova treatment reduced severity of experimental colitis through the regulation of tight junction proteins. Part 2 Effect of schistosome ova on NOD2/CARD15 during TNBS-induced colitisObjective To observe the possible effect of schistosome ova on intestinal NOD2 and to explore the mechanism.Method Fifty mice are randomly divided into three groups,that is control group(group A,n=10),TNBS plus NS group(group B,n=20),TNBS plus schistosome ova group(group C,n=20).The interference and colitis induction are the same as Part One.All mice were killed 7-day after colitis induction,the transcription levels of NOD2 in colon tissues are measured by Real-time PCR,the expressions of NOD2 protein are measured by western blotting.Results The transcription and protein levels of NOD2 in TNBS-induced mice increased compared with normal group(P＜0.05);when compared with TNBS-induced mice,schistosome ova-treated ones experienced a significantly reducement of the gene and protein expressions(P＜0.05).Conclusion NOD2 seems to play a pivotal role in innate immunity against microbial pathogens and regulating the balance between T cells...