Published online Dec 27, 2022. doi: 10.4240/wjgs.v14.i12.1329
Peer-review started: August 25, 2022
First decision: September 2, 2022
Revised: September 11, 2022
Accepted: November 7, 2022
Article in press: November 7, 2022
Published online: December 27, 2022
Processing time: 124 Days and 2 Hours
Patients with mesenteric ischemia frequently suffer from bowel necrosis even after revascularization. Hydrogen gas has showed promising effects for ischemia-reperfusion injury by reducing reactive oxygen species in various animal and clinical studies. We examined intestinal tissue injury by ischemia and reperfusion under continuous initiation of 3% hydrogen gas.
To clarify the treatment effects and target cells of hydrogen gas for mesenteric ischemia.
Three rat groups underwent 60-min mesenteric artery occlusion (ischemia), 60-min reperfusion following 60-min occlusion (reperfusion), or ischemia-reperfusion with the same duration under continuous 3% hydrogen gas inhalation (hydrogen). The distal ileum was harvested. Immunofluorescence staining with caspase-3 and leucine-rich repeat-containing G-protein-coupled 5 (LGR5), a specific marker of intestinal stem cell, was conducted to evaluate the injury location and cell types protected by hydrogen. mRNA expressions of LGR5, olfactomedin 4 (OLFM4), hairy and enhancer of split 1, Jagged 2, and Neurogenic locus notch homolog protein 1 were measured by quantitative polymerase chain reaction. Tissue oxidative stress was analyzed with immunostaining for 8-hydroxy-2'-deoxyguanosine (8-OHdG). Systemic oxidative stress was evaluated by plasma 8-OHdG.
Ischemia damaged the epithelial layer at the tip of the villi, whereas reperfusion induced extensive apoptosis of the cells at the crypt base, which were identified as intestinal stem cells with double immunofluorescence stain. Hydrogen mitigated such apoptosis at the crypt base, and the LGR5 expression of the tissues was higher in the hydrogen group than in the reperfusion group. OLFM4 was also relatively higher in the hydrogen group, whereas other measured RNAs were comparable between the groups. 8-OHdG concentration was high in the reperfusion group, which was reduced by hydrogen, particularly at the crypt base. Serum 8-OHdG concentrations were relatively higher in both reperfusion and hydrogen groups without significance.
This study demonstrated that hydrogen gas inhalation preserves intestinal stem cells and mitigates oxidative stress caused by mesenteric ischemia and reperfusion.
Core Tip: Distal ileum of rats was observed after 60-min mesenteric artery occlusion (ischemia), 60-min reperfusion following 60-min occlusion (reperfusion), or ischemia-reperfusion with the same duration under continuous 3% hydrogen gas inhalation (hydrogen). Immunofluorescence staining with caspase-3 and leucine-rich repeat-containing G-protein-coupled 5 (LGR5) (a specific marker of intestinal stem cell) identified ischemia damaged the epithelial layer at the tip of the villi, whereas reperfusion induced extensive apoptosis of intestinal stem cells that was mitigated by hydrogen. In addition, quantitative polymerase chain reaction revealed the LGR5 expression of the tissues was higher in rats with hydrogen inhalation than in those with reperfusion injury.