Effect of hydrogen gas on intestinal Rho/ROCK signaling pathway in septic mice

Abstract

Objective To evaluate the effect of hydrogen gas (H2) on intestinal Ras homolog gene(Rho)/Rho-associated coiled coil-forming protein kinase(ROCK)signaling pathway in septic mice. Methods Sixty-four male ICR mice, weighing 20-25 g, aged 6 weeks, were randomly divided into 4 groups (n=16 each) using a random number table: sham operation group (group SH), H2 group (group H2), sepsis group (group S) and sepsis+ H2 group (group S+ H2). Sepsis was produced by cecal ligation and puncture (CLP). H2 and S+ H2 groups inhaled 2% H2 for 1 h starting from 1 and 6 h after CLP operation, respectively.Eight mice of each group were selected at 20 h after CLP operation, and gavaged with fluorescein-isothiocyanate-conjugated dextran (FITC-dextran), 4 h later blood samples were obtained by cardiac puncture, and the concentration of FITC-dextran in serum was measured.The left 8 mice in each group were sacrificed at 24 h after CLP operation.After anesthesia, the sterile samples of blood, liver, spleen and kidney were obtained and cultured for bacterial growth to evaluate the condition of bacterial translocation.The intestinal tissues were obtained for examination of the epithelial ultrastructure (by transmission electron microscope), and of the pathological changes which were scored (by light microscope) and for determination of the expression of Rho, ROCK1 and ROCK2 (by Western blot). Results Compared with group SH, the serum concentration of FITC-dextran and pathological scores were significantly increased, the colony-forming units in bacterial culture plates of blood, liver, spleen and kidney were increased, and the expression of Rho, ROCK1 and ROCK2 was up-regulated in S and S+ H2 groups, and no significant change was found in the parameters mentioned above in H2 group.Compared with group S, the serum concentration of FITC-dextran and pathological scores were significantly decreased, the colony-forming units in bacterial culture plates of blood, liver, spleen and kidney were decreased, and the expression of Rho, ROCK1 and ROCK2 was down-regulated, and the pathologic changes of intestines were mitigated in group S+ H2. Conclusion The mechanism by which H2 alleviates the intestinal injury is related to inhibition of the activation of Rho/ROCK signaling pathway in septic mice. Key words: Hydrogen; Sepsis; Rho factor; rho-associated kinases; Intestinal injury