Immune cells, such as neutrophils, and transient receptor potential vanilloid receptor-4 (TRPV4) are known to be associated with inflammatory bowel disease. We have previously reported the importance of masticatory habits using mice that were fed a powdered diet.
In this study, we investigated that the influence of long-term powdered diet feeding on colon function in mice as well as the relationship between neutrophils and TRPV4.
Mice fed a powdered diet for 17 weeks from weaning were compared with mice fed a control diet. RN-1734, TRPV4 antagonist, and sivelestat, neutrophil elastase inhibitor, were used. We investigated the number of fecal pellets and fecal moisture content as indicators of colon function. Further, the colonic expressions of Ly-6G (neutrophil) and TRPV4 were analyzed by western blotting.
Powdered diet feeding significantly decreased the colon function and increased the Ly-6G and TRPV4 expressions. The decreased colon function and the increased expression of TRPV4 were significantly improved by sivelestat. In addition, RN-1734 also improved the decreased colon function in powdered diet fed mice.
These results suggest that the long-term powdered diet feeding causes the decreased colonic function, which may involve activation of neutrophils and TRPV4.