Expression and significance of neutrophil extracellular traps in ulcerative colitis mouse model

Abstract

Objective To investigate the expression of neutrophil extracellular traps (NETs) in ulcerative colitis mouse model and its correlation with the degree of intestinal barrier function. Methods Sixty male Balb/c mice were randomly divided into normal group(n=30) and model group(n=30). An ulcerative colitis model was established by dextran sulfate sodium, and intestinal tissue and blood samples were taken on day 1, day 3, day 5 after modeling(10 mice at each time point). By observing the disease activity index and HE pathological analysis, the intestinal tissue damage was reflected.The cell free DNA was quantified using PicoGreen® dye, and the expression and localization of myeloperoxidase and citrullinated histone in the intestine were observed by immunohistochemistry.Western blot was used to detect the expression of Claudin-1. Results Compared with the normal group, the disease activity index in model group increased significantly (P<0.05). The content of cell free DNA increased significantly (P<0.05). Immunohistochemical examination showed that the formation of NETs in the model group increased, and with the disease recovers, its content gradually decreased.Western blot analysis showed that the expression of claudin-1 in the model group decreased (P<0.05), and with the disease recovers, its content gradually increased. Conclusion The formation of NETs increases in the mouse model of ulcerative colitis, and the increased formation of NETs is associated with impairment of intestinal barrier function. Key words: Inflammatory bowel disease; Neutrophil extracellular traps; Tight junction protein