N-acetylcysteine inhibits activation of toll-like receptor 2 and 4 gene expression in the liver and lung after partial hepatic ischemia-reperfusion injury in mice

BACKGROUND: Toll-like receptor 2 and 4 (TLR2/4) may play important roles in ischemia-reperfusion (I/R) injury, and N-acetylcysteine (NAC) can prevent the generation of reactive oxygen species (ROS) induced by I/R injury. This study aimed to investigate the changes in TLR2/4 gene expression in the liver and lung after I/R injury with or without NAC pretreatment. METHODS: BALB/c mice were used in a model of partial hepatic I/R injury and randomly assigned to a sham-operated control group (SH), a hepatic ischemia/reperfusion group (I/R) or a NAC pretreated, hepatic I/R group (I/R-NAC). The levels of TNF-alpha in the portal vein and plasma alanine aminotransferase (ALT) were measured at 1 and 3 hours after reperfusion. The lung wet-to-dry ratio was measured, and the expression of TLR2/4 mRNA and protein in the liver and lung were assessed with RT-PCR and Western blotting at the same time points. RESULTS: Compared with the I/R group, the expression of TLR2/4 mRNA and protein in the liver and lung in the I/R-NAC group was decreased at the same time point (P<0.05). The levels of portal vein TNF-a and plasma ALT increased continuously in the l/R group at I and 3 hours of reperfusion compared with the SH group; however, they declined significantly in the group pretreated with NAC (P<0.05). The extent of lung edema was relieved in the I/R-NAC group compared with the I/R group (P<0.05). CONCLUSIONS: TLR2/4 was activated in the liver and lung in the process of partial hepatic I/R injury. NAC inhibited the activation of TLR2/4 and the induction of TNF-alpha resulting from I/R injury via modulating the redox state, thus it may mitigate liver and lung injury following partial hepatic I/R in mice.

Gene Expression Profile of Pulmonary Tissues in Different Phases of Lung Ischemia-reperfusion Injury in Rats

In order to provide us new clues to induce some endogenous protective molecular mechanisms, the changes in gene expression profile induced by ischemia-reperfusion in pulmonary tissues of rats were investigated and the dynamic mechanism of pulmonary ischemia-reperfusion injury was elucidated. Thirty male Wistar rats were randomly divided into 6 groups： 5 ischemia-reperfusion （I/R） groups （I/R 0-h, I/R 1-h, I/R 3-h, I/R 6-h, I/R 24-h） and control group （n=5 in each）. An in situ ischemia-reperfusion lung injury rat model was established by occluded hilus of lung. The RatRef-12 Expression Beadchip （22 226 gene probes per array） was used to analyze the pattern of gene expression in all groups. The results showed that 648, 340, 711, 1279 and 641 genes were differentially expressed in I/R 0-, 1-, 3-, 6- and 24-h groups respectively. The differentially expressed genes were classified as following 7 functional categories： cytokine, adhesion molecule, growth factor and apoptosis-related factor, oxidation and antioxidation molecule, metabolic enzyme, ion channel and aquaporin, signal transduction molecule. It was suggested that gene chip technology was an effective and quick method for screening differentially expressed genes. Many differentially expressed genes with different functions interacted each other to result in pulmonary ischemia-reperfusion injury.

Benefit of prophylactic bronchodilator withβ2 adrenergic agonist in ischemia-reperfusion-induced lung injury

Primary lung graft dysfunction could significantly attribute to ischemia-reperfusion lung injury(IRLI)during transplantation surgery.β2-adrenergic agonists were one of the bronchodilators that had been well-established in the management of asthma and chronic obstructive pulmonary disease(COPD)with anti-inflammatory potency.By applying the model of isolated rat lung,we evaluated the efficacy of short-actingβ2-agonist inhalation to ameliorate ischemia-reperfusion damage.The experiment protocol was 180 min of global ischemia and then reperfusion for 60 min.In theβ2-agonist inhalation group,aerosolized albuterol was administrated prior ischemia procedure.Increased weight ratios of wet to dry lung and microvascular permeability were characterized in the IRLI group.In contrast,pre-inhaledβ2-agonist significantly mitigated the severity of pulmonary edema.Bronchoalveolar lavage from theβ2-agonist group presented decreased leukocyte counts and cytokines production,including interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α),and macrophage inflammatory protein 2(MIP-2).Devastating oxidative stress was widely recognized during the ischemia-reperfusion process,whileβ2-agonist pretreatment revealed subsided H2O2,myeloperoxidase(MPO),and the cleavage of caspase-3.Western blotting from lung homogenates identified the blockade of NF-κB and MAPK activation in theβ2-agonist inhalation group.Currently,there was no specific pharmacotherapy in IRLI management.Our results elucidated the protective effect ofβ2-agonist bronchodilator against ischemia-reperfusion induced oxidative stress,inflammation reaction,and pulmonary edema.

EFFECT OF PREOPERATIVE GLUTAMINE ADMINISTRATION ON ICAM-1 EXPRESSION IN RAT LUNG INDUCED BY INTESTINAL ISCHEMIA-REPERFUSION

Objective To evaluate the effect of preoperative glutamine administration on intracellular adhesion molecule-1 （1CAM-l） expression in rat lung induced by intestinal ischemia-reperfusion（ I/R）. Methods Sprague-Dawley rats （n = 25） were randomly divided into 5 groups： sham group （sham surgery）, glutamine groups （three different doses） and control group. All groups except sham were subjected to intestinal 1/R injury, and superior mesenteric artery （SMA） occluded for 60 min followed by 90 min of reperfusion. Lung injury was evaluated with Evans blue dye concentration and histopathologic examination. The immunohistochemical expression and mRNA expression of 1CAM-1 were measured with immunohistochemical staining and RT-PCR method respectively. The level of myeloperoxidase （MPO） was also measured with biochemistry method. Results Intestinal 1/R resulted in lung injury characterized by an increase in Evans blue dye concentration, neutrophil sequestration, and obvious staining for expression of pulmonary 1CAM-l, compared with sham group. The expression of 1CAM-1 and the level of MPO in rat lung were lower in glutamine groups compared with control group. Conclusion 1-R injury increases the expression of 1CAM-1 within the lung. This may contribute to the migration, accumulation and activation of polymorphonuclear neutrophils （PAINs） after such injury. Preoperative glutamine administration attenuates rat lung injury induced by intestinal I-R, and inhibiting 1CAM-1 expression maybe one of the potential mechanisms.

Expression of aquaporin-1 and aquaporin-3 in lung tissue of rat model with ischemia-reperfusion injury

End-stage lung diseases are common and frequentlyoccurring diseases which are difficult for clinical treatment. In recent years, lung transplantation has become a widely accepted and effective therapeutic option for patients with the end-stage pulmonary diseases. Early pulmonary edema resulting from ischemia-reperfusion injury accounts for the major part of mortality and morbidity after lung transplantation. The water channel proteins in lung injury have been little studied, and their impact on the formation of pulmonary edema remains unclear. In this study, we established a rat lung ischemia-reperfusion model to study its impact on the expressions of water channel proteins in lung tissue and explore a new approach to lung transplantation in pulmonary edema pathogenesis.

Edaravone attenuates ischemia-reperfusion injury by inhibiting oxidative stress in a canine lung transplantation model

Background Previous reports have confirmed that edaravone has protective effects against ischemia-reperfusion （IR） injury of many organs. In this study, we investigated the effect of edaravone on preventing IR injury of the lung in a canine lung transplantation model. Methods Twelve weight-matched pairs of random-bred dogs were randomized into two groups. Within each pair, one dog served as donor and the other as recipient. In the study group, prostaglandin EI（PGE1）（8 μg/kg） was injected into the donor pulmonary artery （PA） before occlusion and the donor lungs were flushed with 1.0 L of LPD solution containing edaravone （10 mg/kg） and stored in the same LPD solution at a temperature of 1℃for 8 hours. The left single lung transplantation was then performed and recipients received intravenous injection with edaravone （10 mg/kg） at the onset of reperfusion. In the control group, edaravone was substituted by the same volume of sterile saline solution. Another six dogs were obtained as normal control group in which left lungs were dissected after thoracotomy without an IR injury. One hour after reperfusion, or after dissection of the left lung, the right lung was excluded from perfusion and ventilation after which, cardiopulmonary parameters were measured. Wet/dry ratios, malondialdehyde （MDA） and myeloperoxidase （MPO） levels were assessed and histological analysis of lung tissue performed at the same time. Results All animals survived until the end of the experiment. The study group showed significantly decreased wet/dry ratios （treated： （74.1±4.2）% vs control： （86.8±5.2）%, P 〈0.01）, MDA levels （treated： 0.50±0.08 vs control： 0.88±0.15, P 〈0.01） and MPO activity （treated： 0.23±0.05 vs control： 0.43±0.07, P 〈0.01） compared to the control group two hours after occlusion of the right side. In the control group, pulmonary vascular resistance （PVR） was increased markedly and arterial oxygen partial pressure deteriorated significantly after exclusion of the right side compared to those in the treatment group. Conclusions Edaravone attenuates IR-induced lung injury and preserves lung function by inhibiting oxidative stress and decreasing leukocyte extravasation in a canine lung transplantation model.

Biliverdin Protects the Isolated Rat Lungs from Ischemia-reperfusion Injury via Antioxidative, Anti-inflammatory and Anti-apoptotic Effects

Background：Biliverdin （BV） has a protective role against ischemia-reperfusion injury （IRI）.However,the protective role and potential mechanisms of BV on lung IRI （LIRI） remain to be elucidated.Thus,we aimed to investigate the protective role and potential mechanisms of BV on LIRI.Methods：Lungs were isolated from Sprague-Dawley rats to establish an ex vivo LIRI model.After an initial 15 min stabilization period,the isolated lungs were subjected to ischemia for 60 min,followed by 90 min ofreperfusion with or without BV treatment.Results：Lungs in the I/R group exhibited significant decrease in tidal volume （1.44 ± 0.23 ml/min in I/R group vs.2.41 ± 0.31 ml/min in sham group;P 〈 0.001）,lung compliance （0.27 ± 0.06 ml/cmH2O in I/R group vs.0.44 ± 0.09 ml/cmH2O in sham group;P 〈 0.001;1 cmH2O=0.098 kPa）,and oxygen partial pressure （PaO2） levels （64.12 ± 12 mmHg in FR group vs.114 ± 8.0 mmHg in sham group;P 〈 0.001;1 mmHg =0.133 kPa）.In contrast,these parameters in the BV group （2.27 ± 0.37 ml/min of tidal volume,0.41 ± 0.10 ml/ cmH2O of compliance,and 98.7 ± 9.7 mmHg of PaO2） were significantly higher compared with the I/R group （P =0.004,P 〈 0.001,and P 〈 0.001,respectively）.Compared to the I/R group,the contents of superoxide dismutase were significantly higher （47.07 ± 7.91 U/mg protein vs.33.84 ± 10.15 U/mg protein;P =0.005） while the wet/dry weight ratio （P 〈 0.01）,methane dicarboxylic aldehyde （1.92 ± 0.25 nmol/mg protein vs.2.67 ± 0.46 nmol/mg protein;P 〈 0.001）,and adenosine triphosphate contents （297.05 ± 47.45 nmol/mg protein vs.208.09 ± 29.11 nmol/mg protein;P =0.005） were markedly lower in BV-treated lungs.Histological analysis revealed that BV alleviated LIRI.Furthermore,the expression of inflammatory cytokines （interleukin-1 β,interleukin-6,and tumor necrosis factor-α） was downregulated and the expression of cyclooxygenase-2,inducible nitric oxide synthase,and Jun N-terminal kinase was significantly reduced in BV group （all P 〈 0.01 compared to I/R group）.Finally,the apoptosis index in the BV group was significantly decreased （P 〈 0.01 compared to I/R group）.Conclusion：BV protects lung IRI through its antioxidative,anti-inflammatory,and anti-apoptotic effects.

Macrophage-targeting gene silencing orchestrates myocardial microenvironment remodeling toward the anti-inflammatory treatment of ischemia-reperfusion (IR) injury

Ischemia-reperfusion (IR) injury represents a major cause of myocardial dysfunction after infarction and thrombolytic therapy, and it is closely related to the free radical explosion and overwhelming inflammatory responses. Herein, macrophage-targeting nanocomplexes (NCs) are developed to mediate efficient co-delivery of siRNA against MOF (siMOF) and microRNA-21 (miR21) into myocardial macrophages, cooperatively orches-trating the myocardial microenvironment against IR injury. Bioreducible, branched poly(β-amino ester) (BPAE-SS) is designed to co-condense siMOF and miR21 into NCs in a multivalency-reinforced approach, and they are surface-decorated with carboxylated mannan (Man-COOH) to shield the positive surface charges and enhance the serum stability. The final MBSsm NCs are efficiently internalized by myocardial macrophages after systemic administration, wherein BPAE-SS is degraded into small segments by intracellular glutathione to promote the siMOF/miR21 release, finally provoking efficient gene silencing. Thus, cardiomyocyte protection and macro-phage modulation are realized via the combined effects of ROS scavenging, inflammation inhibition, and autophagy attenuation, which ameliorates the myocardial microenvironment and restores the cardiac function via positive cellular crosstalk. This study renders promising solutions to address the multiple systemic barriers against in vivo nucleic acid delivery, and it also offers new options for IR injury by manipulating multiple reciprocal bio-reactions.

Extracorporeal membrane oxygenation in lung transplantation:Indications,techniques and results

The use of extracorporeal membrane oxygenation(ECMO)in the field of lung transplantation has rapidly expanded over the past 30 years.It has become an important tool in an increasing number of specialized centers as a bridge to transplantation and in the intra-operative and/or post-operative setting.ECMO is an extremely versatile tool in the field of lung transplantation as it can be used and adapted in different configurations with several potential cannulation sites according to the specific need of the recipient.For example,patients who need to be bridged to lung transplantation often have hypercapnic respiratory failure that may preferably benefit from veno-venous(VV)ECMO or peripheral veno-arterial(VA)ECMO in the case of hemodynamic instability.Moreover,in an intraoperative setting,VV ECMO can be maintained or switched to a VA ECMO.The routine use of intra-operative ECMO and its eventual prolongation in the postoperative period has been widely investigated in recent years by several important lung transplantation centers in order to assess the graft function and its potential protective role on primary graft dysfunction and on ischemia-reperfusion injury.This review will assess the current evidence on the role of ECMO in the different phases of lung transplantation,while analyzing different studies on pre,intra-and post-operative utilization of this extracorporeal support.

Necroptosis in ischemia-reperfusion injury of lean and steatotic livers

Hepatic ischemia-reperfusion(IR)injury is a major complication during liver transplantation,liver resection,and other clinical situations.Increased hepatic IR injury in steatotic livers is a major reason for rejecting the use of steatotic livers for liver transplantation.Necroptosis is implicated in the pathogenesis of fatty liver diseases,including non-alcoholic fatty liver disease(NAFLD)and alcoholic liver disease(ALD).Necroptosis is one type of regulated cell death and is regulated by three key proteins:receptorinteracting protein 1(RIP1),receptor-interacting protein 3(RIP3),and mixed-lineage kinase domainlike protein(MLKL).In this review,we examine the necroptosis status in the steatotic liver diseases NAFLD and ALD as well as its role in hepatic IR injury of lean and steatotic livers.

肺缺血再灌注损伤时丝裂原活化蛋白激酶(MAPKs)活性的变化及意义

目的探讨肺缺血再灌注损伤时丝裂原活化蛋白激酶(MAPKs)活性的变化规律及意义。方法取健康Sprague-Dawley大鼠建立在体肺缺血再灌注模型,左肺门夹闭30min,复灌0、10、30、60、90、120min,采用蛋白免疫印迹法(Western blot)检测肺组织中3种丝裂原活化蛋白激酶(MAPKs):ERK(extracellular signal regulated protein kinase,ERK1/2)J、NK(c-Jun NH2-terminal protein kinase,JNK)和p38 MAPK在假手术对照(Sham)组、缺血30min和缺血后再灌注不同时间点的活性变化。结果与假手术对照组相比,ERK、JNK的活性随缺血和再灌注时间的延长而逐渐升高直到复灌120min。p38的活性只在缺血及缺血早期激活而在复灌30min后活性恢复至假手术对照组水平。缺血/再灌注各时点组间ERK、P38、JNK蛋白水平差异无统计学意义(P>0.05)。结论3种丝裂原活化蛋白激酶(MAPKs)在肺缺血再灌介导细胞凋亡中发挥不同的作用。

Comparison of Protective Effects of Safflor Injection and Extract of Ginkgo Biloba on Lung Ischemia/Reperfusion Injury in Rabbits

Objective：To observe the protective effects of safflor Injection（SI） and extract of Ginkgo biloba（EGB） on lung ischemia-reperfusion injury（LIRI） and investigate its mechanism.Methods：In vivo rabbit model of LIRI was reconstructed.Forty rabbits were randomly and equally divided into four groups：sham-operation group（sham group）,ischemia-reperfusion group（model group）,ischemia-reperfusion plus SI group（safflor group） and ischemia-reperfusion plus EGB injection group（EGB group）.Malondialdehyde（MDA） content,superoxide dismutase（SOD） and xanthine oxidase（XO） activity in serum were measured.The wet/dry weight ratio（W/D） of the lung tissue and activity of myeloperoxidase（MPO） were also tested.Ultrastructure change of the lung tissue was observed by the electron microscope.The expression of intercellular adhesion molecule-1（ICAM-1） was measured by immunohistochemistry（IHC）.Results：In the model group,MDA and XO increased and SOD decreased in serum compared with the sham group（P〈0.01）.The values of W/D,MPO and ICAM-1 of the model group were higher than those of the sham group（P〈0.01）,but those of the safflor group and EGB group were significantly lower than those of the model group（P〈0.01）.The IHC demonstrated that ICAM-1 expression in lung tissue of the model group was significantly higher than those of the safflor group（P〈0.01）.Compared with safflor group,in the EGB group MDA,XO,MPO decreased,SOD and ICAM-1expression increased（P〈0.05）,but the change of W/D was not statistically significant（P〉0.05）.Conclusions：SI and EGB may attenuate LIRI through antioxidation,inhibition of neutrophil aggregation and down-regulation of ICAM-1expression.But EGB had more effect on the antioxidation,while SI did better on regulating ICAM-1 expression.