人参皂苷Rg1预处理对大鼠离体心缺血/再灌注损伤的保护作用

目的:探讨人参皂苷Rg1对离体大鼠心缺血/再灌注(I/R)损伤的保护作用。方法:选取SPF级SD大鼠随机分为正常对照组、I/R组、人参皂苷Rg1(1、5、10、20μmol/L)处理组。利用Langendorff灌流系统建立大鼠离体心I/R损伤模型。IabOhart电生理系统实时监测心功能指标,血清生化检测心流出液中心肌酶含量,TTC染色法测定心肌梗死面积。结果:不同浓度人参皂苷Rg1均可改善心肌I/R损伤引起的左室发展压(LVDP)和左室内上升/下降最大速率(±dp/dt_(max))的下降,并降低流出液巾乳酸脱氢酶(LDH)、肌酸激酶同工酶(CK MB)、肌红蛋白(MYO)和肌钙蛋白I(TroI)的含量,显著减少心肌梗死面积。其中5μmol/L和10μmol/L浓度的人参皂苷Rg1对心的保护作用最显著。结论:人参皂苷Rg1具有药物预适应作用,改善心肌I/R损伤后的心肌生理功能,减少流出液中心肌酶的释放和心肌梗死面积,从而发挥抗心肌I/R损伤的保护作用。     

Annexin 1 mimetic peptide protects against renal ischemia/reperfusion injury in rats

Inflammation is currently recognized as a key mechanism in the pathogenesis of renal ischemia–reperfusion (I/R) injury. The importance of infiltrating neutrophil, lymphocytes, and macrophage in this kind of injury has been assessed with conflicting results. Annexin 1 is a protein with potent neutrophil anti-migratory activity. In order to evaluate the effects of annexin A1 on renal I/R injury, uninephrectomized rats received annexin A1 mimetic peptide Ac2-26 (100 μg) or vehicle before 30 min of renal artery clamping and were compared to sham surgery animals. Annexin A1 mimetic peptide granted a remarkable protection against I/R injury, preventing glomerular filtration rate and urinary osmolality decreases and acute tubular necrosis development. Annexin A1 infusion aborted neutrophil extravasation and attenuated macrophage infiltration but did not prevent tissue lymphocyte traffic. I/R increased annexin A1 expression (assessed by transmission electron microscopy) in renal epithelial cells, which was attenuated by exogenous annexin A1 infusion. Additionally, annexin A1 reduced I/R injury in isolated proximal tubules suspension. Annexin A1 protein afforded striking functional and structural protection against renal I/R. These results point to an important role of annexin A1 in the epithelial cells defense against I/R injury and indicate that neutrophils are key mediators for the development of tissue injury after renal I/R. If these results were confirmed in clinical studies, annexin A1 might emerge as an important tool to protect against I/R injury in renal transplantation and in vascular surgery.     

Relaxin protects against myocardial injury caused by ischemia and reperfusion in rat heart.

Myocardial injury caused by ischemia and reperfusion comes from multiple pathogenic events, including endothelial damage, neutrophil extravasation into tissue, platelet and mast cell activation, and peroxidation of cell membrane lipids, which are followed by myocardial cell alterations resulting eventually in cell necrosis. The current study was designed to test the possible cardioprotective effect of the hormone relaxin, which has been found to cause coronary vessel dilation and to inhibit platelet and mast cell activation. Ischemia (for 30 minutes) was induced in rat hearts in vivo by ligature of the left anterior descending coronary artery; reperfusion (for 60 minutes or less if the rats died before this predetermined time) was induced by removal of the ligature. Relaxin (100 ng) was given intravenously 30 minutes before ischemia. The results obtained showed that relaxin strongly reduces 1) the extension of the myocardial areas affected by ischemia-reperfusion-induced damage, 2) ventricular arrhythmias, 3) mortality, 4) myocardial neutrophil number, 5) myeloperoxidase activity, a marker of neutrophil accumulation, 6) production of malonyldialdehyde, an end product of lipid peroxidation, 7) mast cell granule release, 8) calcium overload, and 9) morphological signs of myocardial cell injury. This study shows that relaxin can be regarded as an agent with a marked cardioprotective action against ischemia-reperfusion-induced myocardial injury.     

MiR-183-5p overexpression in bone mesenchymal stem cell-derived exosomes protects against myocardial ischemia/reperfusion injury by targeting FOXO1

ObjectiveExosomes have been suggested to serve as possible drug delivery vehicles due to their nanometer-size range and capability of transferring biological materials to recipient cells. Thus, whether miR-183-5p-overexpressing bone marrow mesenchymal stem cell-derived exosomes (BMSC-Exos) could protect against myocardial ischemia/reperfusion (MI/R) injury by targeting FOXO1 was investigated.MethodsExosomes were isolated from rat BMSCs, and ischemia/reperfusion (I/R) rat models were established. I/R rats were treated with Exo/NC-Exo/miR-183-5p-Exo/anti-miR-183-5p-Exo. Cardiac function, serum biochemical indices, apoptosis, myocardial infarction size, and the expression of miR-183-5p, FOXO1 and cleaved caspase 3 were assessed. Primary cardiomyocytes were isolated to establish hypoxia/reoxygenation (H/R) models to observe the function of miR-183-5p-Exo in vitro.ResultsRats in the I/R group exhibited a decreased left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS) and left ventricular systolic pressure (LVSP) but an increased left ventricular end-diastolic pressure (LVEDP), myocardial infarct size and apoptosis index (AI). In addition, in I/R rats, miR-183-5p expression was decreased, but FOXO1 and cleaved caspase 3 expression was increased. Both Exo and miR-183-5p-Exo improved the above indices in I/R rats, but miR-183-5p-Exo showed better effects. However, anti-miR-183-5p-Exo reversed the protective effect of Exo. FOXO1 was a target gene of miR-183-5p. Experiments in vitro revealed that Exo and miR-183-5p-Exo suppressed apoptosis and oxidative stress injury in H/R-induced cardiomyocytes, whereas overexpressed FOXO1 reversed the protective role of miR-183-5p-Exo.ConclusionBMSC-derived exosomal miR-183-5p could target FOXO1 to reduce apoptosis and oxidative stress in I/R cardiomyocytes and improve cardiac function, thereby protecting against MI/R injury.     

莫诺苷通过AMPKα/PGC-1α/GLUT4通路对糖尿病大鼠缺血再灌注损伤的保护作用

目的：心血管并发症是糖尿病患者发病和死亡的主要原因。本文旨在探索莫诺苷对糖尿病大鼠缺血再灌注损伤的影响及其机制。方法：利用高糖饮食联合链脲佐菌素(STZ)诱导糖尿病大鼠模型。冠状动脉结扎术建立缺血再灌注模型。糖尿病大鼠随机分为4组：对照组(DM);对照加药组(DM+莫诺苷);模型组(I/R+DM);加药组(I/R+DM+莫诺苷)。苏木素伊红(HE)染色分析组织病理学变化。ELISA检测炎症因子TNF-α、IL-6、IL-10水平和氧化应激指标SOD和MDA水平。蛋白印迹检测肌红蛋白（Mb）、肌酸激酶同工酶(CK-MB)、肌钙蛋白I(cTn I)、AMPKα1、PGC-1α和GLUT4的表达。结果：与对照组相比,模型组平均动脉压(MAP)、心率(HR)和左心室收缩压(LVSP)明显降低,心肌梗死面积增大(P<0.05)。与模型组相比,加药组MAP、HR和LVSP明显升高,心肌梗死面积明显变小(P<0.05)。同时,莫诺苷可改善糖尿病大鼠缺血再灌注导致的心肌组织病变。模型组Mb、CK-MB和 cTn I 表达明显高于对照组(P<0.05)。加药组Mb,CK-MB和 cTn I 表达明显低于模型组(P<0.05)。与对照组相比,模型组TNF-α和 IL-6水平明显升高,IL-10水平明显下降(P<0.05)。与模型组相比,加药组TNF-α和 IL-6水平明显降低,IL-10水平明显上升(P<0.05)。而且,模型组SOD水平明显低于对照组,MDA水平明显高于对照组(P<0.05)。与模型组相比,加药组SOD水平升高,MDA水平降低(P<0.05)。另外,模型组AMPKα1、PGC-1α和GLUT4的表达明显低于对照组(P<0.05)。加药组AMPKα1、PGC-1α和GLUT4的表达明显高于模型组(P<0.05)。结论：莫诺苷通过激活AMPKα/PGC-1α/GLUT4通路减轻糖尿病大鼠缺血再灌注损伤。     

Engeletin protects against cerebral ischemia/reperfusion injury by modulating the VEGF/vasohibin and Ang-1/Tie-2 pathways

Engeletin is a natural derivative of Smilax glabra rhizomilax that exhibits anti-inflammatory activity and suppresses lipid peroxidation. In the present study, we sought to elucidate the mechanistic basis for the neuroprotective and pro-angiogenic activity of engeltin in a human umbilical vein endothelial cells (HUVECs) oxygen-glucose deprivation and reoxygenation (OGD/R) model system and a middle cerebral artery occlusion (MCAO) rat model of cerebral ischemia and reperfusion injury. These analyses revealed that engeletin (10, 20, or 40 mg/kg) was able to reduce the infarct volume, increase cerebral blood flow, improve neurological function, and bolster the expression of vascular endothelial growth factor (VEGF), vasohibin-2 (Vash-2), angiopoietin-1 (Ang-1), phosphorylated human angiopoietin receptor tyrosine kinase 2 (p-Tie2), and platelet endothelial cell adhesion molecule-1 (PECAM-1/CD31) in MCAO rats. Similarly, engeletin (100, 200, or 400 nM) markedly enhanced the migration, tube formation, and VEGF expression of HUVECs in an OGD/R model system, while the VEGF receptor (R) inhibitor axitinib reversed the observed changes in HUVEC tube formation activity and Vash-2, VEGF, and CD31 expression. These data suggested that engeletin exhibited significant neuroprotective effects against cerebral ischemia and reperfusion injury in rats, and improved cerebrovascular angiogenesis by modulating the VEGF/vasohibin and Ang-1/Tie-2 pathways.     

Polymerized human placenta hemoglobin given before ischemia protects rat heart from ischemia reperfusion injury

This study was to investigate whether polymerized human placenta hemoglobin (PolyPHb) given before ischemia protects in vivo rat heart function against ischemia/reperfusion (I/R) injury. Forty-five male Sprague-Dawley rats were randomly divided (n = 15 per group) into a sham group, control group (pretreatment with Lactated Ringer's solution), or PolyPHb group (pretreatment with 0.1 gHb/kg PolyPHb). Rat hearts were subjected to 30-min ischemia by occlusion of left anterior descending, followed by 2-hr reperfusion. As compared to the control group, PolyPHb preserved cardiac function and reduced cardiac troponin-I release and histopathological changes. Therefore, PolyPHb pretreatment provided a profound cardioprotective effect on the in vivo rat heart.     

Lutein protects against ischemia/reperfusion injury in rat skeletal muscle by modulating oxidative stress and inflammation

Abstract

Background: Lutein is an antioxidant compound with potential biological effects. The present study investigated the protective role of Lutein against I/R injury in skeletal muscle.

Methods: Animals were divided into three groups. Group I – sham operated; Group II- IR injury- Hind limb ischemia was induced by clamping the common femoral artery and vein. After 4?h of ischemia, the clamp was removed and the animals underwent 2?h of reperfusion. Group III-Lutein?+?IR injury- Rats with Lutein treatment received intraperitoneal injection 1?h before reperfusion. The skeletal tissues were analyzed for oxidative stress parameters (reactive oxygen species, protein carbonylation and sulfhydryls, lipid peroxidation). Antioxidant status was determined by evaluating Nrf-2 levels and antioxidant enzyme activities. The inflammatory mechanism was determined through NF-κB and COX-2 expressions. Pro-inflammatory cytokines were determined by ELISA.

Results: The results showed that Lutein treatment significantly decreased the oxidative stress by reducing reactive oxygen species, protein carbonylation and sulphydryls, lipid peroxidation. Further, the levels of Nrf-2 and antioxidant status was significantly declined during IR injury compared to sham operated rats. Lutein treatment reduced the oxidative stress by enhancing Nrf-2 levels and antioxidant status. Skeletal IR injury enhanced the inflammatory signaling by up regulating NF-κB, COX-2 and various pro-inflammatory cytokines. NF-κB, COX-2 expressions were down regulated by Lutein treatment.

Conclusion: The study shows that Lutein protects against skeletal IR injury by down regulating oxidative stress and inflammatory mechanisms.     

Vascular endothelial growth factor antagonist modulates leukocyte trafficking and protects mouse livers against ischemia/reperfusion injury

Although hypoxia stimulates the expression of vascular endothelial growth factor (VEGF), little is known of the role or mechanism by which VEGF functions after ischemia and reperfusion (I/R) injury. In this report, we first evaluated the expression of VEGF in a mouse model of liver warm ischemia. We found that the expression of VEGF increased after ischemia but peaked between 2 and 6 hours after reperfusion. Mice were treated with a neutralizing anti-mouse VEGF antiserum (anti-VEGF) or control serum daily from day -1 (1 day before the initiation of ischemia). Treatment with anti-VEGF significantly reduced serum glutaminic pyruvic transaminase levels and reduced histological evidence of hepatocellular damage compared with controls. Anti-VEGF also markedly decreased T-cell, macrophage, and neutrophil accumulation within livers and reduced the frequency of intrahepatic apoptotic terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling-positive cells. Moreover, there was a reduction in the expression of pro-inflammatory cytokines (tumor necrosis factor-alpha and interferon-gamma), chemokines (interferon-inducible protein-10 and monocyte chemoattractant protein-1) and adhesion molecules (E-selectin) in parallel with enhanced expression of anti-apoptotic genes (Bcl-2/Bcl-xl and heme oxygenase-1) in anti-VEGF-treated animals. In conclusion, hypoxia-inducible VEGF expression by hepatocytes modulates leukocyte trafficking and leukocyte-induced injury in a mouse liver model of warm I/R injury, demonstrating the importance of endogenous VEGF production in the pathophysiology of hepatic I/R injury.     

Carbon monoxide inhalation protects rat intestinal grafts from ischemia/reperfusion injury

Carbon monoxide (CO), a byproduct of heme catalysis by heme oxygenases, has been shown to exert anti-inflammatory effects. This study examines the cytoprotective efficacy of inhaled CO during intestinal cold ischemia/reperfusion injury associated with small intestinal transplantation. Orthotopic syngenic intestinal transplantation was performed in Lewis rats after 6 hours of cold preservation in University of Wisconsin solution. Three groups were examined: normal untreated controls, control intestinal transplant recipients kept in room air, and recipients exposed to CO (250 ppm) for 1 hour before and 24 hours after surgery. In air grafts, mRNA levels for interleukin-6, cyclooxygenase-2, intracellular adhesion molecule (ICAM-1), and inducible nitric oxide synthase rapidly increased after intestinal transplant. Histopathological analysis revealed severe mucosal erosion, villous congestion, and inflammatory infiltrates. CO effectively blocked an early up-regulation of these mediators, showed less severe histopathological changes, and resulted in significantly improved animal survival of 92% from 58% in air-treated controls. CO also significantly reduced mRNA for proapoptotic Bax, while it up-regulated anti-apoptotic Bcl-2. These changes in CO-treated grafts correlated with well-preserved CD31(+) vascular endothelial cells, less frequent apoptosis/necrosis in intestinal epithelial and capillary endothelial cells, and improved graft tissue blood circulation. Protective effects of CO in this study were mediated via soluble guanylyl cyclase, because 1H-(1,2,4)oxadiazole (4,3-alpha) quinoxaline-1-one (soluble guanylyl cyclase inhibitor) completely reversed the beneficial effect conferred by CO. Perioperative CO inhalation at a low concentration resulted in protection against ischemia/reperfusion injury to intestinal grafts with prolonged cold preservation.     

Isorhamnetin protects rat ventricular myocytes from ischemia and reperfusion injury

Ischemia/reperfusion (I/R) has been known to cause damages to ventricular myocytes. Isorhamnetin, one member of flavonoid compounds, has cardioprotective effect, the effect that suggests a possible treatment for I/R damages. In the present investigation, we found that isorhamnetin could significantly promote the viability of neonatal rat ventricular myocytes that were exposed to ischemia/reperfusion (I/R) in vitro. Ventricular myocytes were obtained from neonatal SD rats, and then were divided randomly into three groups, namely I/R?/isor?, I/R+/isor? and I/R+/isor+ group. Before the whole experiment, the most appropriate concentration of isorhamnetin (4 μM) was determined by MTT assay. Our results showed that isorhamnetin could alleviate the damages of I/R to ventricular myocytes through inhibiting lactate dehydrogenase (LDH) activity, and repressing apoptosis. Compared with the counterpart of the I/R+/isor? group, LDH activity in the isorhamnetin-treated group weakened, halving from 24.1±2.3 to 11.4±1.2 U/L. Additionally, flow cytometry showed the apparently increased apoptosis rate induced by I/R, the result that was further confirmed by transmission electron microscope. Administration of isorhamnetin, however, assuaged the apoptosis induced by I/R. Corresponding to the reduced apoptosis rate in the I/R+/isor+ group, western blotting assay showed increased amount of Bcl-2 and p53, decreased amount of Bax, and nuclear accumulation of NF-κB/p65.     

人参皂苷Rb1改善自噬流抗离体大鼠心脏心肌缺血再灌注损伤

目的通过Langendorff系统构建离体大鼠心肌缺血/再灌注(I/R)损伤模型,探讨人参皂苷Rb1对心肌I/R损伤的保护作用及机制。方法选取健康成年雄性SD大鼠60只,随机分为假手术组、I/R组和人参皂苷Rb1(1、5、10和20μmol/L)预处理组,每组10只。大鼠开胸、结扎主动脉后,取出心脏置于Langendorff系统进行灌流,按照分组情况构建相应模型。采用Lab Chart电生理系统检测心率(HR)、左心室发展压(LVDP)、左室压上升/下降最大速率(±dp/dtmax)等相关心功能指标;采用TTC染色法检测心肌梗死面积;采用Western blotting检测Beclin 1、LC3、p62和Lamp 2表达情况;采用免疫组织化学法检测Beclin 1表达情况。结果人参皂苷Rb1(1、5、10和20μmol/L)改善由I/R损伤导致的LVDP和±dp/dtmax的下降,减少心肌梗死面积,其中10μmol/L浓度人参皂苷Rb1对心功能保护作用最显著(P<0.05)。Beclin 1在I/R组心肌细胞胞质中阳性表达率显著增高,加入人参皂苷Rb1(10μmol/L)后表达量减少(P<0.05)。与sham组相比,在I/R组发现自噬流受损:自噬相关蛋白Beclin 1、LC3和p62表达水平升高,Lamp 2表达水平下调(P<0.05)。加入人参皂苷Rb1(10μmol/L)后上述蛋白的调控作用被反转,自噬流通畅(P<0.05)。结论人参皂苷Rb1预处理通过改善自噬流受损发挥抗大鼠离体心肌I/R损伤的保护作用,其中以10μmol/L浓度的人参皂苷Rb1保护作用最好。     

Administration of dexamethasone protects mice against ischemia/reperfusion induced renal injury by suppressing PI3K/AKT signaling

Dexamethasone (DEX), a ligand for glucocorticoid receptor (GR), has long been used in the clinical practice due to its anti-inflammatory and immunosuppressive properties. Given that ischemia/reperfusion (IR)-induced renal injury is featured by the excessive immune response; the current study is therefore designed to address the impact of dexamethasone on IR-induced renal injury, a common disorder in the clinical settings. Precondition of mice with 4 mg/kg of dexamethasone significantly attenuated IR-induced injury as manifested by the improved renal function along with ameliorated pathological changes and suppressed inflammatory infiltration. Mechanistic studies revealed that dexamethasone promotes GR activation, and by which it attenuates the signals for PI3K/AKT activation. Attenuated PI3K/AKT signaling thus suppresses inflammatory response which then protects kidneys from IR-induced injury. All together, our data support that dexamethasone could be a good alternative therapy for prevention and treatment of IR-induced renal injury in the clinical practice.     

Magnesium isoglycyrrhizinate protects hepatic L02 cells from ischemia/reperfusion induced injury

Human liver ischemia/reperfusion injury (IRI) is a common and major clinical problem complicating liver surgery and transplantation. The pathogenesis underlying IRI is complex, involving a series of signaling mediators and mechanisms. This study aimed to investigate the effects of Magnesium Isoglycyrrhizinate (MgIG) on the changes of oxidant stress and apoptosis induced by IRI in human hepatic L02 cells. L02 cells with IRI were treated with or without MgIG and mitoKATP (Mitochondrial adenosine triphosphate-dependent potassium) channel modulators. Cell viability was assessed using CCK-8 assay. Cell apoptosis was quantified by flow cytometry. The activity of the antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were measured. Effects of MgIG on the expression of Bax, Bcl-2, Caspase 3, PARP (poly ADP-ribose polymerase), Akt, and ERK in L02 cells with IRI were examined. Our results showed that MgIG treatment significantly reduced the population of apoptotic cells and the expression of apoptosis-related proteins in hepatic L02 cells with IRI. MgIG also counteract ischemia reperfusion induced oxidative challenge as it effectively reduced malondialdehyde (MDA) and increased the activities of SOD and GSH-Px. L02 cells treated with MgIG showed increased expression of p-Akt and p-ERK, indicating that the protective effect of MgIG might be associated with the activation of Akt and ERK pathways. Moreover, the addition of Diazoxide (DE), a mitoKATP channel opener, enhanced the cytoprotective activity of MgIG, while the mitoKATP blocker 5-hydroxydecanoate (5-HD) reduced the cytoprotective activity of MgIG.     

血红素氧合酶-1在大鼠供肝中的表达及其对供肝缺血再灌注损伤的防护作用

目的探讨血红素氧合酶-1（HO—1）在大鼠同种异体移植肝脏中的表达及其对供肝缺血再灌注损伤的防护作用。方法96只WiS1ar大鼠随机分为正常对照组（c组）、生理盐水预处理组（S1组）、钴原卟啉预处理组（S2组）和锌原卟啉预处理组（S3组）。C组6只，各预处理组分别为30只。各预处理组随机取出24只分为供受体，供体于预处理后24h行原位肝移植，分别于门静脉复流后1h和3h各取6只取血及肝组织；余6只仅行预处理，于供体预处理后24h取血及肝组织，分别检测血清ALT、AST、TNF—α水平、肝组织形态学变化及HO—1蛋白表达水平。结果①血清转氨酶水平：与C组相比，供肝预处理后24h，各组血清转氨酶水平无显著性差异（P〉0．05），门静脉复流后各时间点，S2组血清转氨酶水平均低于S1组和S组（P〈0．05），S1组低于S组（P〈0．05）；②HO—1表达水平：C组基本无表达；预处理后24h，S组肝脏HO—1mRNA及其蛋白即有较高表达，S1组和S3组只有极少量表达；门静脉复流后各时间点，S2组均高于S1组和S组（P〈0．05），S1组高于％组（P〈0．05）；③肝脏形态学变化：与C组相比，移植肝门静脉复流后3h，＆组肝脏损伤轻于S1组和S3组，S1组轻于S组。结论HO—1在同种异体肝移植大鼠肝脏中的过表达可显著改善移植后的肝脏功能，减轻供肝的缺血再灌注损伤。     

GYY4137 protects against myocardial ischemia and reperfusion injury by attenuating oxidative stress and apoptosis in rats

Hydrogen sulfide（H₂S） is a gasotransmitter that regulates cardiovascular functions.The present study aimed to determine the protective effect of slow-releasing H₂S donor GYY4137 on myocardial ischemia and reperfusion（I/R） injury and to investigate the possible signaling mechanisms involved.Male Sprague-Dawley rats were treated with GYY4137 at 12.5 mg/（kg·day）,25 mg/（kg·day） or 50 mg/（kg·day） intraperitoneally for7 days.Then,rats were subjected to 30 minutes of left anterior descending coronary artery occlusion followed by reperfusion for 24 hours.We found that GYY4137 increased the cardiac ejection fraction and fractional shortening,reduced the ischemia area,alleviated histological injury and decreased plasma creatine kinase after myocardial I/R.Both H₂S concentration in plasma and cystathionine-γ-lyase（CSE） activity in the myocardium were enhanced in the GYY4137 treated groups.GYY4137 also decreased malondialdehyde and myeloperoxidase levels in serum,attenuated superoxide anion level and suppressed phosphorylation of mitogen activated protein kinases in the myocardium after I/R.Meanwhile,GYY4137 increased the expression of Bcl-2 but decreased the expression of Bax,caspase-3 activity and apoptosis in the myocardium.The data suggest that GYY4137 protects against myocardial ischemia and reperfusion injury by attenuating oxidative stress and apoptosis.     

Fibronectin-alpha 4 beta 1 integrin-mediated blockade protects genetically fat Zucker rat livers from ischemia/reperfusion injury

We tested a hypothesis that interactions between fibronectin (FN), the major extracellular matrix component, and its integrin alpha 4 beta 1 receptor is important in the development of ischemia/reperfusion injury of steatotic liver transplants. We examined the effect of connecting segment-1 (CS1) peptide-facilitated blockade of FN-alpha 4 beta 1 interaction in a well-established steatotic rat liver model of ex vivo cold ischemia followed by iso-transplantation. In this model, CS1 peptides were administered through the portal vein of steatotic Zucker rat livers before and after cold ischemic storage. Lean Zucker recipients of fatty liver transplants received an additional 3-day course of CS1 peptides after transplant. CS1 peptide therapy significantly inhibited the recruitment of T lymphocytes, neutrophil activation/infiltration, and repressed the expression of proinflammatory tumor necrosis factor-alpha and interferon-gamma. Moreover, it resulted in selective inhibition of inducible nitric oxide synthase expression, peroxynitrite formation, and hepatic necrosis. Importantly, CS1 peptide therapy improved function/histological preservation of steatotic liver grafts, and extended their 14-day survival in lean recipients from 40% in untreated to 100% in CS1-treated OLTs. Thus, CS1 peptide-mediated blockade of FN-alpha 4 beta 1 interaction protects against severe ischemia/reperfusion injury experienced otherwise by steatotic OLTs. These novel findings document the potential of targeting FN-alpha 4 beta 1 in vivo interaction to increase the transplant donor pool through modulation of marginal steatotic livers.