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Objective To evaluate the role of necroptosis in liver injury induced by intestinal ischemia-reperfusion (I/R) in rats.Methods Thirty-two healthy adult male Sprague-Dawley rats,weighing 250-300 g,were divided into 4 groups (n=8 each) using a random number table:sham operation group (S group),I/R group,specific necroptosis inhibitor necrostatin-1 group (N group) and dimethyl sulfoxide (DMSO) group (D group).Intestinal I/R was produced by occlusion of the superior mesenteric artery for 1.5 h followed by 6 h of reperfusion.The superior mesenteric artery was only isolated but not ligated in group S.At 30 min before ischemia,necrostatin-1 1 mg/kg (diluted to 200 μl in DMSO) was intraperitoneally injected in group N,while the equal volume of DMSO was given instead in group D.The animals were sacrificed at the end of reperfusion,livers were removed for examination of the pathological changes with a light microscope,and the severity of liver injury was evaluated using the Eckhoff's scale score.Blood samples were collected from the cardiac apex for determination of serum alanine transaminase (ALT) concentrations by enzyme-linked immunosorbent assay.The expression of receptor-interacting protein kinase 1 (RIP1),RIP3 and high-mobility group box 1 protein (HMGB1) in cytoplasm of hepatocytes was detected by Western blot.The location of RIP1 and RIP3 in liver tissues was determined by immunohistochemistry,and the translocation of HMGB1 from nucleus to cytoplasm was tested by immunofluorescence.Results Compared with group S,the Eckhoff's scale score of liver tissues and serum ALT concentration were significantly increased,the expression of RIP1,RIP3 and HMGB1 in liver tissues was up-regulated (P＜0.05),and the hepatocytes in which RIP1 and RIP3 were highly expressed in the portal area were increased in group I/R.Compared with group I/R,the Eckhoff's scale score of liver tissues and serum ALT concentration were significantly decreased,the expression of RIP1,RIP3 and HMGB1 in liver tissues was down-regulated (P＜0.05),and the hepatocytes in which RIP1 and RIP3 were highly expressed in the portal area were decreased in group N,and no significant changes were found in the variables mentioned above in group D (P＞0.05).HMGB1 was expressed in the nucleus of hepatocytes in the portal area in group S;a large number of HMGB1 in hepatocytes in the portal area was translocated to cytoplasm in I/R and D groups;a small number of HMGB1 in hepatocytes in the portal area was translocated to cytoplasm in group N.Conclusion Necroptosis is involved in intestinal I/R-induced liver injury in rats.
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Objective To evaluate the effect of remifentanil preconditioning ( RP ) on intestinal is?chemia?reperfusion ( I∕R) injury in rats and its relationship with opioid receptors. Methods Seventy?two Sprague?Dawley rats, aged 6-7 weeks, weighing 250-280 g, were randomly divided to 9 groups ( n=8 each): sham operation group (S), intestinal I∕R group (group I∕R), RP group, different opioid receptor antagonists groups (N, BNI and CTOP groups), and opioid receptor antagonists + RP groups (N+RP, BNI+RP and CTOP+RP groups) . Intestinal I∕R was produced by clamping the superior mesenteric artery for 1 h followed by 2 h reperfusion in all the groups except group S. RP was induced by 3 cycles of 5 min infusion of remifentanil 0?2 μg·kg-1 ·min -1 followed by 5 min infusion of normal saline before ischemia. Naltrindole (δ?receptor antagonist, 5 mg∕kg) , nor?binaltorphimine (κ?receptor antagonist, 5 mg∕kg) and CTOP (μ?receptor antagonist, 1 mg∕kg) were administered before RP. At 2 h of reperfusion, blood sam?ples were collected from the cardiac apex for determination of serum diamine oxidase ( DAO) activity. Intes? tinal tissues were then removed for microscopic examination. Intestinal damage was assessed and scored ac?cording to Chiu. Apoptosis in intestinal mucosal epithelial cells was detected using TUNEL assay, and ap?optosis index was calculated. The expression of activated caspase?3 in intestinal mucosal epithelial cells was measured by Western blot. Results Compared with group S, the serum DAO activity, Chiu′s score, and apoptosis index were significantly increased, and the expression of activated caspase?3 was up?regulated in I∕R and RP groups ( P0?05). Compared with group RP, the serum DAO activity, Chiu′s score, and apoptosis index were significantly increased, and the expression of activa?ted caspase?3 was up?regulated in N+RP and CTOP+RP groups ( P0?05) . Conclusion RP can mitigate in?testinal I∕R injury in rats, and the mechanism is related to the anti?apoptotic effect mediated by activation ofδ?and μ?opioid receptors, but not κ?opioid receptors.
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Aim To investigate the the protective effects of a novel recombinant Trichinella spiralis 38 ku protein ( rTsP38 ) on intestinal I/R injury and the po-tential mechanisms. Methods Male BALB/c mice were randomly divided into sham group ( group S) , in-jury group ( group I) , rTsP38 vaccinated group ( group T) and adjuvants vaccinated group ( group A ) , and received subcutaneously phosphate buffer solution (PBS), PBS, rTsP38, or adjuvants, respectively, at 2-week intervals 6 weeks before the surgical proce-dure. Results Intestinal I/R caused severe intestinal injury evidenced by significant increases in modified Chiu 's score and neutrophils infiltration, accompanied by decreases in daily food intake and body weight. The mRNA level of arginase-1 ( Arg-1 ) was decreased and the mRNA level of inducible nitric oxide synthase 2 ( NOS2) was increased in group I. RTsP38 significant-ly ameliorated intestinal injury and improved intestinal function following intestinal I/R accompanied by de-crease in neutrophils infiltration and increase in cell proliferation in the intestine, compared to mice without rTsP38 pretreatment. Fold changes of Arg-1 mRNA level were significantly increased in group T. Conclu-sions These findings indicate that rTsP38 exerts pro-tection on intestinal I/R injury in mice via promoting M2 macrophages polarization.
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Objective To evaluate the role of necroptosis in intestinal ischemia-reperfusion (I/R) injury in rats.Methods Thirty-two healthy male Sprague-Dawley rats,weighing 200-220 g,were randomly assigned into 4 groups (n =.8 each) using a random number table:sham operation group (Sham group),I/R group,necroptosis inhibitor necrostatin-1 group (Nec-1 group) and solvent dimethyl sulfoxide (DMSO) group (group DMSO).Intestinal I/R injury was produced by clamping the superior mesenteric artery for 1 h followed by 24 h reperfusion in rats anesthetized with chloral hydrate.Necrostatin-1 1.0 mg/kg was administered intraperitoneally at 30 min before occlusion in Nec-1 group,while the equal volume of DMSO was given instead in group DMSO.The rats were sacrificed at 24 h of reperfusion and the intestinal tissues were removed for microscopic examination.Intestinal damage was assessed and scored according to Chiu.Blood samples were taken for determination of serum diamine oxidase (DAO) activity.The expression of activitied caspase-3 and receptor-interacting protein 1 (RIP1) in intestinal tissues was detected using Western blot.Results Compared with Sham group,Chiu's score,serum DAO activity,and the expression of activitied caspase-3 and RIP1 was up-regulated in I/R,DMSO and Nec-1 groups.Compared with I/R and DMSO groups,Chiu's score and DAO activity were significantly decreased,the expression of RIP1 was down-regulated,and no significant change was found in the expression of activitied caspase3 in group Nec-1.Conclusion Necroptosis is involved in intestinal I/R injury in rats.