Hydrogen-rich saline protects intestinal epithelial tight junction barrier in rats with intestinal ischemia-reperfusion injury by inhibiting endoplasmic reticulum stress-induced apoptosis pathway.

Aim: To investigate the effects of hydrogen-rich saline (HRS) on intestinal epithelial tight junction (TJ) barrier in rats with intestinal ischemia-reperfusion injury (IIRI).

Materials And Methods: Thirty-two healthy male Sprague-Dawley (SD) rats were randomly divided into four groups (n = 8 each): Sham group, I/R group, HRS group and 4-PBA group. After 45 min of ischemia and 6 h of reperfusion, the rats were sacrificed to collect serum and ileum for detection. Hematoxylin and eosin (H&E) staining was used to observe the morphology of small intestine. The serum expression levels of intestinal fatty acid binding protein (IFABP), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) were determined by enzyme linked immunosorbent assay (ELISA). Imunohistochemistry, immunofluorescence and Western blot were used to detect key proteins in intestinal epithelial TJs, ERS, and ERS-induced apoptosis, including occludin, zonula occludens-1 (ZO-1), glucose-regulated protein 78 (GRP78), X-box binding protein-1 (XBP1), C/EBP-homologous protein (CHOP) and caspase-3. Data was presented as mean ± SEM and compared using one-way ANOVA. A p-value <0.05 was considered significant.

Results: Compared with rats in the I/R group, the Chiu score of ileum damage in the HRS group and 4-PBA group were lower. The levels of serum IFABP, TNF-α, and IL-1β were statistically significant among the groups. Increased expression of TJ proteins occludin and ZO-1 by reducing various parameters of ERS and ERS-induced apoptosis evidenced by down-regulation of the protein levels of GRP78, XBP1, CHOP and caspase-3 were shown in the HRS and 4-PBA groups.

Conclusion: HRS had potential protective effects on intestinal barrier in IIRI rats. This study suggested that inhibition of excessive ERS and ERS-induced apoptosis by HRS may reduce intestinal epithelial cells damage and maintain the integrity of intestinal epithelial TJ barrier in rats with IIRI.