The effect of murine intestine ischemia-reperfusion on endogenous ligand of TLR4 expression in distant organs

Objective To investigate the expression of high mobility group box 1 (HMGBI) of TLR4 endogenous ligand and distant organ tissue injury after intestine ischemia/reperfusion and drainage of lymph fluid in rats. Methods Twenty-four Sprague-Dawley (SD) male rats (SPF grade) were evenly divided into 3 groups:Sham surgery group,intestine ischemia-reperfusion (I/R) group,and intestine ischemia-reperfusion with drainage of intestine lymph fluid (IR + drainage) group.The injury of distant organs such as lungs,liver,kidney was evaluated;The expression of high mobility group box 1 (HMGBI) of TLR4 endogenous ligand in intestine,lung and liver after the ischemia-reperfusion injury was measured by immunohistochemistry.Result HE stained sections,as well as HMGB1 immunohistochemistry results showed that the injury of ischemia/reperfusion (I/R) group and ischemia/reperfusion (I/R) + drainage group were more severe than that in the sham group.A large number of cells stained in I/R group,indicating that HMGB1 expression increased.The injury in I/R + drainage group was significantly less severe than I/R group.Western blot tests showed that the expression of HMGB1 in jejunum,ileum,liver,lung increased significantly in I/R group after L/R injury.Gray-scale values of HMGB1/β-actin were 0.3145 ± 0.0549、 1.7352 ± 0.3280、1.4443 ± 0.0926、3.1382 ± 0.4202.Lymph drainage significantly alleviated the damage,the expression of HMGB1 were significantly lower (P ＜0.05).Gray-scale values of HMGB1/β-actin were 0.1745 ± 0.0327、 1.1083 ± 0.2098、 1.1862 ± 0.1221、2.1095 ± 0.1993. Conclusion Increased expression of HMGB1 of TLR4 endogenous ligand is associated with intestinal and distant tissue injury during intestinal ischemia-reperfusion injury.Drainage of lymph fluid can block the gutlymph pathway and thus reduce the source of HMGB1 from the intestinal as well as the injury of distant tissue. Key words: Ischemia; Reperfusion injury; Toll-like receptor 4; High mobility group proteins