Effect of nuclear factor kappa B on intercellular adhesion molecule-1 expression and neutrophil infiltration in lung injury induced by intestinal ischemia/reperfusion in rats

AIM： To investigate the role of nuclear factor kappa B （NF-κB） in the pathogenesis of lung injury induced by intestinal ischemia/reperfusion （I/R）, and its effect on intercellular adhesion molecule-1 （ICAM-1） expression and neutrophil infiltration. METHODS： Twenty-four Wistar rats were divided randomly into control, I/R and pyrrolidine dithiocarbamate （PDTC） treatment groups, n = 8 in each. I/R group and PDTC treatment group received superior mysenteric artery （SMA） occluding for 1 h and reperfusion for 2 h. PDTC group was administrated with intraperitoneal injection of 2% 100 mg/kg PDTC 1 h before surgery. Lung histology and bronchia alveolus lung fluid （BALF） protein were assayed. Serum IL-6, lung malondialdehyde （MDA） and myeloperoxidase （MPO） as well as the expression level of NF-κB and ICAM-1 were measured.RESULTS： Lung injury induced by intestinal I/R, was characterized by edema, hemorrhage and neutrophil infiltration as well as by the significant rising of BALF protein. Compared to control group, the levels of serum IL-6 and lung MDA and MPO increased significantly in I/R group （P=0.001）. Strong positive expression of NF-κB p65 and ICAM-1 was observed. After the administration of PDTC, the level of serum IL-6, lung MDA and MPO as well as NF-κB and ICAM-1 decreased significantly （P〈 0.05） when compared to I/R group.CONCLUSION： The activation of NF-κB plays an important role in the pathogenesis of lung injury induced by intestinal I/R through upregulating the neutrophil infiltration and lung ICAM-1 expression. PDTC as an inhibitor of NF-κB can prevent lung injury induced by intestinal I/R through inhibiting the activity of NF-κB.

Protective effect of pyrrolidine dithiocarbamate on liver injury induced by intestinal ischemia-reperfusion in rats

BACKGROUND: The nuclear translocation of transcription factors may be a critical factor in the intracellular pathway involved in ischemia/reperfusion(I/R) injury. The aim of the study was to evaluate the role of nuclear factor-kappa B (NF-κB) in the pathogenesis of liver injury induced by intestinal ischemia/reperfusion (IIR) and to investigate the effect of pyrrolidine dithiocarbamate (PDTC) on this liver injury. METHODS: Male Wistar rats were divided randomly into three experimental groups (8 rats in each): sham operation group (control group); intestinal/reperfusion group(I/R group): animals received 1-hour of intestinal ischemia and 2-hour reperfusion; and PDTC treatment group (PDTC group): animals that received I/R subject to PDTC treatment (100 mg/kg). The histological changes in the liver and intestine were observed, and the serum levels of tumor necrosis factor-α (TNF-α), alanine aminotransferase (ALT), aspartate aminotransferase (AST), liver superoxide dismutase (SOD), and nitrite/nitrate (NO) were measured. The immunohistochemical expression and Western blot analysis of liver NF-κB and intercellular adhesion molecule-1(ICAM-1) were observed. RESULTS: IIR induced liver injury characterized by the histological changes of liver edema, hemorrhage, polymorphonuclear neutrophil (PMN) infiltration, and elevated serum levels of AST and ALT. The serum TNF-α level was significantly higher than that of the control group(P<0.01) and a high level of liver oxidant product was observed (P<0.01). These changes were parallel to the positive expression of NF-κB and ICAM-1. After the administration of PDTC, the histological changes after liver injury were improved; the levels of SOD and NO in the liver were elevated and reduced, respectively (P<0.01). The expressions of ICAM-1 and NF-κB in the liver were weakened (P<0.01). CONCLUSION: NF-κB plays an important role in the pathogenesis of liver injury induced by HR. PDTC, an agent known to inhibit the activation of NF-κB, can reduce and prevent this injury.

Recombinant angiopoietin-like protein 4 attenuates intestinal barrier structure and function injury after ischemia/reperfusion

BACKGROUND Intestinal barrier breakdown,a frequent complication of intestinal ischemiareperfusion(I/R)including dysfunction and the structure changes of the intestine,is characterized by a loss of tight junction and enhanced permeability of the intestinal barrier and increased mortality.To develop effective and novel therapeutics is important for the improvement of outcome of patients with intestinal barrier deterioration.Recombinant human angiopoietin-like protein 4(rhANGPTL4)is reported to protect the blood-brain barrier when administered exogenously,and endogenous ANGPTL4 deficiency deteriorates radiationinduced intestinal injury.AIM To identify whether rhANGPTL4 may protect intestinal barrier breakdown induced by I/R.METHODS Intestinal I/R injury was elicited through clamping the superior mesenteric artery for 60 min followed by 240 min reperfusion.Intestinal epithelial(Caco-2)cells and human umbilical vein endothelial cells were challenged by hypoxia/reoxygenation to mimic I/R in vitro.RESULTS Indicators including fluorescein isothiocyanate-conjugated dextran(4 kilodaltons;FD-4)clearance,ratio of phosphorylated myosin light chain/total myosin light chain,myosin light chain kinase and loss of zonula occludens-1,claudin-2 and VE-cadherin were significantly increased after intestinal I/R or cell hypoxia/reoxygenation.rhANGPTL4 treatment significantly reversed these indicators,which were associated with inhibiting the inflammatory and oxidative cascade,excessive activation of cellular autophagy and apoptosis and improvement of survival rate.Similar results were observed in vitro when cells were challenged by hypoxia/reoxygenation,whereas rhANGPTL4 reversed the indicators close to normal level in Caco-2 cells and human umbilical vein endothelial cells significantly.CONCLUSION rhANGPTL4 can function as a protective agent against intestinal injury induced by intestinal I/R and improve survival via maintenance of intestinal barrier structure and functions.

Protective effects of terminal ileostomy against bacterial translocation in a rat model of intestinal ischemia/reperfusion injury

AIM: To investigate the effects of terminal ileostomy on bacterial translocation (BT) and systemic inflammation after intestinal ischemia/reperfusion (I/R) injury in rats.

Impact of intestinal ischemia/reperfusion and lymph drainage on distant organs in rats

AIM:To investigate the impact of intestinal ischemia/reperfusion(I/R) injury and lymph drainage on distant organs in rats.METHODS:Thirty-two Sprague-Dawley male rats,weighing 280-320 g,were randomly divided into blank,sham,I/R,and ischemia/reperfusion and drainage(I/R + D) groups(n = 8).All rats were subjected to 60 min ischemia by clamping the superior mesenteric artery,followed by 120 min reperfusion.The rats in the I/R + D group received intestinal lymph drainage for 180 min.In the sham group,the abdominal cavity was opened for 180 min,but the rats received no treatment.The blank group served as a normal and untreated control.A chromogenic limulus assay kit was used for quantita-tive detection of serum endotoxin.The serum concentrations of tumor necrosis factor-α(TNF-α),interleukin(IL)-6,IL-1β,soluble cell adhesion molecules(sICAM-1),and high mobility group protein box 1(HMGB1) were determined with an enzyme-linked immunosorbent assay kit.Histological evaluations of the intestine,liver,kidney,and lung were performed by hematoxylin and eosin staining and immunohistochemistry.HMGB1 protein expression was assayed by western blot analysis.RESULTS:The serum levels of endotoxin and HMGB1 in the I/R and I/R + D groups were significantly higher than those in the sham group(endotoxin,I/R and I/R + D vs sham:0.033 ± 0.004 EU/mL,0.024 ± 0.003 EU/mL vs 0.017 ± 0.009 EU/mL,respectively,P < 0.05;HMGB1,I/R and I/R + D vs sham:5.473 ± 0.963 EU/mL,4.906 ± 0.552 EU/mL vs 0.476 ± 0.406 EU/mL,respectively,P < 0.05).In addition,endotoxin and HMGB1 were significantly lower in the I/R + D group compared to the I/R group(P < 0.05).The serum inflammatory factors IL-6,IL-1β,and sICAM-1 in the I/R and I/R + D groups were significantly higher than those in the sham group(IL-6,I/R and I/R + D vs sham:41.773 ± 9.753 pg/mL,19.204 ± 4.136 pg/mL vs 11.566 ± 2.973 pg/mL,respectively,P < 0.05;IL-1β,I/R and I/R + D vs sham:144.646 ± 29.378 pg/mL,65.829 ± 10.888 pg/mL vs 38.178 ± 7.157 pg/mL,respectively,P < 0.05;sICAM-1,I/R and I/R + D vs sham:97.360 ± 12.714 ng/mL,48.401 ± 6.547 ng/mL vs 33.073 ± 5.957 ng/mL,respectively;P < 0.05).The serum TNF-α in the I/R group were significantly higher than in the sham group(45.863 ± 11.553 pg/mL vs 18.863 ± 6.679 pg/mL,respectively,P < 0.05).These factors were significantly lower in the I/R + D group compared to the I/R group(P < 0.05).The HMGB1 immunohistochemical staining results showed no staining or apparent injury in the blank group,and slight staining at the top of the microvillus was detected in the sham group.In the I/R group,both the top of villi and the basement membrane were stained for HMGB1 in most areas,and injury in the I/R + D group was less than that in the I/R group.HMGB1 expression in the liver,kidney,and lung of rats in the I/R + D group was significantly lower than the rats in the I/R group(P < 0.05).CONCLUSION:Lymph drainage could block the "gutlymph" pathway,improve intestinal barrier function,and attenuate distant organ injury incurred by intestinal I/R.

Intestinal ischemia-reperfusion of macaques triggers a strong innate immune response

AIM: To investigate inflammatory injury in the intestinal mucosa after intestinal ischemia-reperfusion (IIR) with Toll-like receptor (TLR)-mediated innate immunity. METHODS: Ten macaques were randomized into control and IIR groups. The distribution and expression level of TLR2, TLR4, MD2, nuclear factor (NF)-kappa B p65 and interferon (IFN)-gamma were measured by immunohistochemical stain and western blotting. The mRNA expression of TLR4, TLR2, MD2, interleukin (IL)-1 beta and tumor necrosis factor (TNF)-alpha were measured by reverse transcriptase-polymerase chain reaction. The cytokine levels in blood and intestinal tissues were measured by ELISA. RESULTS: Obvious hemorrhage and erosion of mucosae were seen in the IIR group. Expression of TLR2, TLR4, MD2, NF-kappa B p65 and IFN-gamma. was significantly higher in the IIR group than in the control group (0.13 +/- 0.04, 0.22 +/- 0.04, 0.16 +/- 0.06, 0.65 +/- 0.12, 0.38 +/- 0.10 vs 0.07 +/- 0.04, 0.08 +/- 0.03, 0.04 +/- 0.02, 0.19 +/- 0.06, 0.14 +/- 0.05, P < 0.05). In addition, the expression of TLR2, TLR4, MD2, IL-1 beta and TNF-alpha mRNA in the IIR group were significantly higher than those of control group(1.52 +/- 0.15, 1.39 +/- 0.06, 1.94 +/- 0.12, 1.48 +/- 0.15, 0.66 +/- 0.08 vs 0.31 +/- 0.05, 0.5 +/- 0.04, 0.77 +/- 0.05, 0.35 +/- 0.08, 0.18 +/- 0.04, P < 0.05). Furthermore, IL-1 beta, IL-6 and TNF-alpha levels in the macaques ileum and plasma were significantly higher than in the control group (plasma: 86.3 +/- 15.2, 1129 +/- 248.3, 77.8 +/- 16.2 vs 29.5 +/- 7.3, 19.8 +/- 8.2, 5.6 +/- 1.7; ileum: 273.4. +/- 44.7, 1636 +/- 168.0, 205.5 +/- 30.7 vs 76.8 +/- 20.5, 663.4 +/- 186.9, 49.0 +/- 9.4; P < 0.05). CONCLUSION: After IIR, general inflammatory injury in the intestinal mucosa is correlated with a strong innate immune response, mediated by activation of the TLR-NF-kappa B-cytokine pathway. (C) 2014 Baishideng Publishing Group Inc. All rights reserved.

Influence of cromolyn sodium and compound 48/80 administered prior to and after reperfusion on the third day＇s survival rate in a rat intestinal ischemia model

Intestinal ischemia occurs in a wide variety of clinical manifestations. The gut barrier is broken down by bacterial translocation after small intestinal ischemia reperfusion injury （IIRI）, which can result in many clinical consequences, even death. The intestinal mucosal mast cells （IMMCs） serve as a unique cellular source of large amounts of vasoactive mediators, and they can influence local tissue reactions. We and others have previously shown that IIRI could activate IMMCs, make them degranulate and release a mass of inflammatory mediators, which in turn aggravate IIRI.

Protective effect of electroacupuncture preconditioning at zúsānlǐ(足三里 ST36) on mitochondria in the intestinal ischemia/reperfusion injury

Objective： The study explored the effect of applying electroacupuncture（EA） preconditioning at ST 36 on mitochondria in rats with intestinal ischemia/reperfusion injury.Methods： Forty SD rats were divided into four sets： sham operation group（sham group）; intestinal ischemia/reperfusion group（I/R group）; EA preconditioning at ST 36 followed by intestinal ischemia/reperfusion injury（ST 36 ＋ I/R group）; EA preconditioning at the lateral site away from ST360.5 cm followed by intestinal ischemia/reperfusion injury（N＋I/R group）. For the sham group, the rats were opened abdominal cavity for 3 h and 20 min and their abdominal cavities were covered with wet gauze avoiding drying and kept on the thermostat at 37 0 C. For the ischemia/reperfusion（I/R） group,rats were anaesthetised and their abdominal cavities were opened to expose jejunum segments. The segment＇s collateral blood supply was restricted by bilateral ligation of the intestine. Next, one of the branches of a mesenteric artery was occluded with a thread for 20 min and then the thread was released after such ischemia conditions, keeping reperfusion for 3 h. For the ST36 ＋ I/R group, the electroacupuncture at ST36 was first performed, then the intestinal ischemia/reperfusion model was constructed. For the N ＋ I/R group, electroacupuncture at non ST36 acupoint, which is away from ST36 about 0.5 cm, and then the intestinal ischemia/reperfusion model was performed. Measurements of the levels of inflammatory markers tumour necrosis factor a（TNFa） and interleukin-1 beta（IL-1β）, cytochrome c（CYCS）, and the mitochondrial membrane pro-apoptotic protein（BAX）, anti-apoptotic protein Bcl-2 were performed.Results： Compared to I/R group, the intensity of cytoplasmic CYCS in intestinal tissues was significantly decreased in the ST 36 ＋ I/R group（1.65 vs. 0.18, p〈0.05）. Compared to N ＋ I/R group, the intensity of cytoplasmic CYCS in intestinal tissues was also dramatically declined in the ST 36 ＋ I/R group（1.37 vs. 0.18, p〈0.05）. The level of CYCS in mitochondria in rats in the ST 36 ＋ I/R group were appreciably increased than those of rats in the I/Rgroup（1.42 vs. 0.06, p〈0.05）, and CYCS in mitochondria was also largely expressed in ST36 ＋ I/R group than N ＋ I/R group（1.42 vs. 0.08, p〈0.05）. Bcl-2 was shown to be elevated in the ST 36 ＋ I/R group than I/R group（1.01 vs. 0.10） and N ＋ I/R group（1.01 vs. 0.09, all p〈0.05）, whereas BAX expression was greatly decreased in the ST36 ＋ I/R group than I/R group（0.11 vs.0.78） and N ＋ I/R group（0.11 vs. 0.87, all p〈0.05）.Conclusion： The results suggest the EA intervention has a protective effect upon mitochondria, preventing CYCS release and the subsequent activation of downstream apoptosis pathway. It is proposed that patients due to undergo gastrointestinal surgery get benefit from EA preconditioning at ST 36.