Expression And Significance Of Neutrophil Extracellular Traps In Ulcerative Colitis Mouse Model

Objective: To investigate the expression of neutrophil extracellular traps(NETs)in Ulcerative colitis mouse model,and to elucidate the correlation between NETs and the degree of intestinal barrier function damage,by detecting the expression of tight junction protein(claudin-1).Methods:Sixty male Balb/cmice were randomly divided into normal group and model group.An Ulcerative colitis model was established by dextran sulfate sodium(DSS),and intestinal tissue and blood samples were taken at 1 d,3 d,and 5 d after modeling.By observing the clinical manifestations of each group of mice,the disease activity index score and conventional HE pathological analysis were performed to reflect the intestinal tissue damage and confirm the formation of colitis.The content of free DNA in mouse plasma was quantitatively detected by Pico Green? dye.The expression and localization of myeloperoxidase(MPO)and citrullin histone(Cit H3),the main components of NETs in intestinal tissue,were observed by immunohistochemistry.Western blot was used to detect the expression level of claudin-1,and the correlation between NETs and intestinal barrier function was determined.Results : Compared with the normal group,the DSS-induced ulcerative colitis mice showed significant weight loss after modeling,and the pathological changes of HE showed obvious colitis changes,and the body weight gradually increased with time,each model group The inflammatory activity index DAI was significantly higher than that of the normal control group(P<0.05).The plasma free DNA content of the mice in each model group was significantly higher than that in the normal control group(P<0.05),and gradually recovered with the disease,and the content gradually decreased.Immunohistochemical examination showed that the formation of NETs increased in each model group,and gradually recovered with the disease,and its content gradually decreased.Western blot analysis showed that the expression of tight junction protein claudin-1 decreased in all model groups(P<0.05),and gradually recovered with the disease,and its content gradually increased.Conclusion: The formation of NETs is increased in the mouse model of Ulcerative colitis,and the increased formation of NETs is associated with impairment of intestinal barrier function.