Maresin1 alleviates small intestinal ischemia-reperfusion injury by inhibiting the Caspase11/GSDMD pathway via Sirt1

Abstract:

Objective To investigate the role and possible mechanisms of Maresin1（Mar1） in intestinal ischemia-reperfusion（IR） in mice.Methods Clamping of the superior mesenteric artery（SMA） was performed to establish a model of small intestinal IR. In the first part of the experiment，12 mice were randomly divided into Control group，IR group，and IR+Mar1 group，and in the second part，20 mice were randomly divided into Control group，IR group，IR+Mar1 group，IR+EX527 group，and IR+Mar1+EX527 group. Mar1 5 μg/kg was injected intraperitoneally at 30 min before surgery，and EX527 10 mg/kg was injected intraperitoneally at 1 day before surgery. In the control group，the SMA was isolated without clamping，and in the other model groups，the root of the SMA was clamped with a damage-free vascular clip，which was released after 45 min to establish a model of small intestinal IR. Venous blood and ileal specimens were collected at 4 hours after reperfusion in all groups. For the first part of the experiment，the levels of superoxide dismutase（SOD），malondialdehyde（MDA），and glutathione（GSH） in the intestinal tissue of each group were measured，as well as the serum level of FITC-Dextran 4000（FD-4）； immunofluorescent staining was used to measure the protein expression level of intestinal Occludin；HE staining was used to observe the pathological morphology of intestinal tissue. For the first and second parts of the experiment，western blot was used to measure the protein expression levels of Sirt1，P-NF-κB p65（P-p65），Caspase11，and GSDMD-N in intestinal tissue.Results In the first part of the experiment，compared with the Control group，the IR group had significant increases in the level of MDA in intestinal tissue，the content of FD-4 in serum，and the degree of pathological damage（P<0.01），significant reductions in the protein expression levels of SOD，GSH，and Sirt1，and significant increases in the protein expression levels of P-p65，Caspase11，and GSDMD-N； compared with the IR group，the IR+Mar1 group had significant reductions in the level of MDA in intestinal tissue，the content of FD-4 in serum，and the degree of pathological damage（P<0.05），significant increases in the protein expression levels of SOD，GSH，and Sirt1，and significant reductions in the protein expression levels of P-p65，Caspase11，and GSDMD-N. In the second part of the experiment，compared with the IR+Mar1 group，the IR+Mar1+EX527 group had a significant reduction in the protein expression level of Sirt1 and significant increases in the protein expression levels of P-p65，Caspase11，and GSDMD-N，while there was no significant difference in the expression of proteins between the IR+EX527 group and the IR+Mar1+EX527 group.Conclusion Mar1 pretreatment can alleviate small intestinal IR injury by inhibiting the Caspase11/GSDMD pathway via Sirt1.