Butyric acid is potent protective agent that targets RhoA/ROCK2/MLCK signaling pathway in LPS-induced intestinal mucosal barrier damage

Abstract Butyric acid (BA) could improve intestinal barrier function, meanwhile RhoA/ROCK2/MLCK signaling pathway has been confirmed vital in the maintenance of intestinal epithelial permeability. However, the specific mechanism by which BA protects intestine mucosal barrier still needs to be clarified. Here, the optimal time and concentration were explored. Then, cell growth status, TEER and FD-4 permeability, the mRNA expression of ZO-1 and Occludin, RhoA, ROCK2 and MLCK, and the expression and distribution of them in Caco2 were detected. After that, RhoA/ROCK2/MLCK pathway inhibitor Y-27632 was adopted. The final concentration of 0.2mM BA and 5ug/ml LPS treatment for 24 h was confirmed. Compared with LPS alone, BA improved the growth state of Caco2 cells, restored the declined TEER, reduced FD-4 permeability, improved the mRNA expression of ZO-1, Occludin and restored their distrbution, as well as inhibited the mRNA expression of RhoA, ROCK2 and MLCK, and the reversed their location. After treatment of Y-276432, the cell growth state and mucosal barrier function, the mRNA expression of ZO-1 and Occludin and their location were further improved, while the pathway was inhibitied. This study provided complementary data for BA as a potential target for attenuating LPS-induced intestinal barrier injury through inhibiting the RhoA/ROCK2/MLCKpathway.