Factor In Ischemia-reperfusion Injury Research Articles

MCU inhibition protects against intestinal ischemia‒reperfusion by inhibiting Drp1-dependent mitochondrial fission

Intestinal ischemia‒reperfusion (IIR) injury is a common complication of surgery, but clear molecular insights and valuable therapeutic targets are lacking. Mitochondrial calcium overload is an early sign of various diseases and is considered a vital factor in ischemia‒reperfusion injury. The mitochondrial calcium uniporter (MCU), which is located on the inner mitochondrial membrane, is the primary mediator of calcium ion entry into the mitochondria. However, the specific mechanism of MCU in IIR injury remains to be clarified. In this study, we generated an IIR model using C57BL/6 mice and Caco-2 cells and found increases in the calcium levels and MCU expression following IIR injury. The specific inhibition of MCU markedly attenuated IIR injury. Moreover, MCU knockdown alleviates mitochondrial dysfunction by reducing oxidative stress and apoptosis. Mechanistically, MCU knockdown substantially reduced the translocation of Drp1 and thus its binding to Fis1 receptors, resulting in decreased mitochondrial fission. Taken together, our findings demonstrated that MCU is a novel upstream regulator of Drp1 in ischemia‒reperfusion and represents a predictive and therapeutic target for IIR.

Evaluation of the efficacy of HEMO2life®, a marine OXYgen carrier for Organ Preservation (OxyOp2) in renal transplantation: study protocol for a multicenter randomized trial

BackgroundPreventing ischemia‒reperfusion injury (IRI) is a major issue in kidney transplantation, particularly for transplant recipients receiving a kidney from extended criteria donors (ECD). The main consequence of IRI is delayed graft function (DGF). Hypoxia is one of the key factors in IRI, suggesting that the use of an oxygen carrier as an additive to preservation solution may be useful. In the OxyOp trial, we showed that the organs preserved using the oxygen carrier HEMO2life® displayed significantly less DGF. In the OxyOp2 trial, we aim to definitively test and quantify the efficacy of HEMO2life® for organ preservation in a large population of kidney grafts.MethodsOxyOp2 is a prospective, multicenter, randomized, comparative, single-blinded, parallel-group study versus standard of care in renal transplantation. After the selection of a suitable donor according to the inclusion/exclusion criteria, both kidneys will be used in the study. Depending on the characteristics of the donor, both kidneys will be preserved either in static cold storage (standard donors) or on machine perfusion (for ECD and deceased-after-cardiac-death donors (DCD)). The kidneys resulting from one donor will be randomized: one to the standard-of-care arm (organ preserved in preservation solution routinely used according to the local practice) and the other to the active treatment arm (HEMO2life® on top of routinely used preservation solution). HEMO2life® will be used for ex vivo graft preservation at a dose of 1 g/l preservation solution. The primary outcome is the occurrence of DGF, defined as the need for renal replacement therapy during the first week after transplantation.DiscussionThe use of HEMO2life® in preservation solutions is a novel approach allowing, for the first time, the delivery of oxygen to organs. Improving graft survival by limiting ischemic lesions is a major public-health goal in the field of organ transplantation.Trial registrationClinicalTrials.gov, ID: NCT04181710. registered on November 29, 2019.

Risk Factors of Ischemia Reperfusion Injury After PCI in Patients with Acute ST-Segment Elevation Myocardial Infarction and its Influence on Prognosis.

PurposeTo explore the risk factors of ischemia reperfusion injury (IRI) after percutaneous coronary intervention (PCI) in patients with acute ST-segment elevation myocardial infarction (STEMI) and its influence on prognosis.MethodsThe clinical data of 80 patients with STMEI undergoing PCI in our hospital from June 2020 to June 2021 were collected. According to whether IRI occurred after PCI, STMEI patients were divided into IRI group and non-IRI group. The basic information, clinical characteristics, examination parameters and other data of all patients were collected, and the prognosis of the two groups was observed. Risk factors were analyzed by fitting binary Logistic regression model. The survival prognosis was analyzed by Kaplan-Meier survival curve.ResultsLogistic regression analysis showed that type 2 diabetes mellitus (T2DM), pre-hospital delay time (PHD) and door-to-balloon expansion time (DTB) were the influencing factors of IRI in patients with STMEI (p < 0.05). MACE occurred in 11 cases (32.35%) in the IRI group and 13 cases (28.26%) in the non-IRI group. Log-rank test showed p = 0.503, indicating no statistically significant difference.ConclusionT2DM, PHD and DTB were the influencing factors of IRI in patients with STMEI, and IRI will not reduce the prognosis of patients.

Protective Effect of Epigallocatechin Gallate in Ischemia-Reperfusion Injury of Rat Skeletal Muscle

BackgroundReactive oxygen species–induced cell injury has been considered to be one of the main etiologic factors in ischemia-reperfusion injury (IRI). As a potential antioxidant agent, epigallocatechin gallate (EGCG) was examined in skeletal muscle of the rats after IRI with or without treatment. Materials and methodsTourniquet application applied to the rats’ hind limbs was selected as the appropriate IRI method. Animals were randomly distributed to one of the following groups: (1) sham control + SF (saline) (10 mg/kg/i.p.) (SC-SF), (2) IRI (4 + 2 h) + SF (10 mg/kg/i.p.) (IRI-SF), (3) IRI and EGCG (25 mg/kg/i.p.) (IRI-EG25), and (4) IRI and EGCG (50 mg/kg/i.p) (IRI-EG50). In another set of experiments with identical groups, the only difference was that the reperfusion period was 24 h. A number of different parameters relating to the damage seen in the skeletal muscles, lungs, kidneys, and liver and particular cytokines were measured by proper analytical methods. ResultsIn comparison with the SC-SF group, IRI (4 + 2 h) induced an increase in the total oxidative status of skeletal muscle (10.17 ± 0.61 versus 15.74 ± 1.10) and blood creatine phosphokinase (CPK) (669.88 ± 50.23 versus 7202.38 ± 766.13) and lactate dehydrogenase levels (686.00 ± 67.48 versus 1343.00 ± 113.01). Although 25 mg/kg EGCG could not reverse these parameters to their normal levels, the higher dose of EGCG, that is, 50 mg/kg, was sufficient to prevent the increases seen in total oxidative status (8.55 ± 0.85) and CPK levels (4741.63 ± 339.40). In addition, reduced total antioxidant status of skeletal muscle in the IRI-SF group (0.50 ± 0.06) was elevated by the administration of EGCG (50 mg/kg) (0.85 ± 0.04). Regarding remote organ injury, only alanine transaminase (ALT) and aspartate transaminase (AST) levels were found to be increased, showing a slight damage in liver tissue. However, neither dose of EGCG was able to prevent this deleterious effect. As for cytokines (interleukin-1β, IL-6, IL-8, tumor necrosis factor-α, and monocyte chemotactic protein-1), there were no differences between the study groups. In regard to long-term IRI (i.e., 4 + 24 h), statistically significantly elevated parameters in the IRI-SF group were as follows: CPK, lactate dehydrogenase, creatinine (Cr), and blood urea nitrogen. On the other hand, none of them were influenced by either dose of EGCG. According to the results, EGCG demonstrates a considerable protective effect toward IRI (4 + 2 h) of skeletal muscle. ConclusionsAlthough oxidative stress seems to play a significant role both in the pathogenesis of IRI and in the mechanism of action of EGCG, there is no evidence that inflammatory cytokines are, at least in our model, crucial mediators regarding the former events.

Effect of Aliskiren on Renal Cortical Ischemia/Reperfusion Injury in Albino Rats: A Histological and Immunohistochemical Study

Background: Ischemia/reperfusion injury (IRI) is a foremost reason for acute kidney injury, which is a common clinical complication having high morbidity rate and lacks effective therapy. Renin-angiotensin system (RAS) activation and angiotensin II level elevation are important risk factors in IRI. Aliskiren (ALS) is the first oral direct rennin inhibitor that blocks the first step in RAS and has been approved for treating hypertension.Aim of work: Investigating whether ALS pretreatment protects the renal cortex of adult male albino rats subjected to IRI.Material and Methods: Thirty adult male albino rats were divided into 3 groups: group I (control group), group II (IRI group): were subjected to IRI procedure, group III (ALS group): rats were pretreated with aliskiren (ALS, 100 mg/kg) twice orally 24h and 1h before IRI and left for 24h of reperfusion before scarification. Blood samples were taken to estimate the levels of blood urea nitrogen (BUN), serum creatinine (SCr) and superoxide dismutase enzyme (SOD). Kidneys sections were stained with HandE and PAS stains and immunohistochemical staining against COX-2 and caspase-3. This was followed by morphometric and statistical analysis.Results: IRI group showed deterioration in renal function tests with massive histological alterations in the Malpighian renal corpuscles and the convoluted tubules. There was significant decrease in optical density of PAS reaction, with significant increase in the mean area% of COX-2 and caspase-3 immunoexpression. ALS group showed significant improvement in renal function tests with preserved normal histology of the renal cortex. There was significant increase in the optical density of PAS reaction, with significant decrease in the mean area% of COX-2 and caspase-3 immunoexpression.Conclusion: A protective effect of ALS was detected in IRI-induced renal cortical damage in adult male albino rats. This was evidenced by laboratory results, histological and immunohistochemical evaluation.

The role of vascular endothelial growth factor in ischemia-reperfusion injury of testis

OBJECTIVE: Testicular torsion causes ischemia-reperfusion injury of testis and leads to male factor infertility. Its injury initiates a pathophysiologic cascade. In recent studies, protective effect of VEGF has been shown in various forms of ischemia- reperfusion injury. However, no study has investigated the role of VEGF in testicular ischemia-reperfusion injury. The aim of our study was to investigate the time course expression of VEGF, VEGF-receptor (R)1, VEGF-R2, inducible and endothelial nitric oxide synthase (iNOS and eNOS) and to evaluate the effect of VEGF in ischemia-reperfusion injury of testis. DESIGN: Animal study. MATERIALS AND METHODS: Using 8-week-old SD rat, surgery for making unilateral experimental torsion was performed. After 1 hour of torsion, the testis was counter-rotated back to the natural position and reinserted into the scrotum. Bilateral castrations were performed in various time courses after reperfusion. Western bolt analysis and immunohistochemical evaluation were used to determine the activation of VEGF, iNOS, and eNOS. VEGF, VEGF-R1 and -R2 mRNAs were measured by reverse transcription PCR (RT-PCR) and quantitative real-time PCR (QRT-PCR) analysis. RESULTS: In torsion side testis, the expression of VEGF protein and mRNA significantly increased in a time dependent manner since 3 to 120 hour after reperfusion. Although the expression of VEGF-R1 mRNA was increased in a similar way, which of VEGF-R2 mRNA could not be detected. The increase of VEGF protein expression was observed in testicular vascular endothelial cells and seminiferous tubular endothelial cells. Significant activation of iNOS and eNOS were investigated at 12 and 24 hours after reperfusion. CONCLUSIONS: Our study is the first report in the literature to show the time course expression of VEGF in torsion caused ischemia-reperfusion injury testis. Further investigations, such as VEGF infusion study, may lead to a novel approach for the therapy of ischemia-reperfusion injury of the testis.

Research progress in regulatory factors of ischemia reperfusion injury induced by diabetic retinopathy

糖尿病视网膜病变(DR)是一种常见的缺血性眼病.DR视网膜缺血再灌注(RIR)损伤的缺血过程、再灌注损伤过程及其结局3个阶段中氧化应激、钙超载、一氧化氮(NO)、兴奋性氨基酸(EAA)等因素引起多种炎性介质和基因过度表达,进而造成炎症反应、损伤、凋亡和坏死等组织改变和功能障碍.这些过程受凋亡基因、促红细胞生成素、单核细胞趋化蛋白1、血管内皮生长因子(VEGF)、碱性成纤维细胞生长因子(bFGF)、基质细胞衍生因子 1、NO、一氧化氮合酶(NOS)等多种相关因子的调控.就其中主要调控因子的特点及临床应用方面的研究进展进行综述。

Role of Nitric Oxide in Ischemia-Reperfusion Injury and Acute Rejection in Rat Intestinal Transplantation

Objective This study was designed to evaluate the role of nitric oxide (NO) in ischemia-reperfusion injury (IRI) and acute rejection (AR) in rat intestinal transplantation, using administration of the NO inhibitor N G-nitro-L-arginine methyl ester (L-NAME). Materials and Methods Rats that underwent orthotopic allogeneic intestinal transplantation were assigned to 2 groups. In the normal allograft group (Wistar to Sprague-Dawley rats), L-NAME 0 mg/kg/d (group 1-1), 4 mg/kg/d (group 1-2), 8 mg/kg/d (group 1-3), or 12 mg/kg/d (group 1-4) was injected intraperitoneally. In the high responder allograft group (Dark Agouti to Lewis rats), L-NAME 0 mg/kg/d (group 2-1) or 8 mg/kg/d (group 2-2) was injected intraperitoneally. Survival times were observed and maltose absorption tests performed as well as light microscopic examination of the grafts. Results The mean survival time of group 1-3 was significantly prolonged compared with group 1-1 ( P < .01). In group 2, the survival time of group 2-2 was significantly prolonged compared with group 2-1 ( P < .01). Histological changes showed IRI was attenuated in group 1–2 compared with group 1-1, whereas it was aggravated in groups 1-3 and 1-4. Treatment with L-NAME (8 mg/kg/d) attenuated the graft damage of AR in groups 1 and 2. Maltose absorption tests showed that inhibition of NO impaired maltose absorption. Conclusion This study suggested that NO plays a dual role as both a cytotoxic and a cytoprotective factor in IRI, and may serve as a kind of cytotoxic medium in AR in rat intestinal allotransplantation.

Very early alloantigen-independent trafficking of lymphocytes during ischemic acute kidney injury

Lymphocytes play an important role during ischemia-reperfusion injury (IRI). Lai et al. have demonstrated, for the first time, an increase in kidney lymphocytes 1 hour after IRI, a newly identified kidney lymphocyte reservoir, and have confirmed the pathogenic role of lymphocytes by manipulating the sphingosine-1-phosphate (SIP)-sphingosine-1-phosphate type 1 (S1P1) receptor pathway.

Interleukin-8 Expression in Lung Tissue During Ischemia-Reperfusion

Local cytokine production is a pathogenic factor in ischemia-reperfusion injury in early graft dysfunction. This study analyzed interleukin 8 (IL-8) messenger RNA (mRNA) expression in lung tissue and the association between IL-8 mRNA levels and interstitial lung changes in an experimental model of warm lung ischemia-reperfusion. We studied 16 New Zealand rabbits divided into 3 groups: control, ischemia (tissue taken from right lower lobe after 1, 2, or 3 hours of ischemia), and reperfusion (tissue taken from right upper and middle lobes after 1 hour of ischemia and 1, 2, or 3 hours of reperfusion). Expression of IL-8 mRNA was determined by reverse transcription and polymerase chain reaction. Interstitial infiltration by polymorphonuclear neutrophils was determined. The Mann-Whitney U-test was used for statistical comparisons, with P< .05 considered to indicate a significant result. During ischemia, IL-8 mRNA levels were elevated at the end of hour 1 (P=.009) with respect to the control group, but not thereafter. Interstitial changes were minimal. IL-8 mRNA levels during reperfusion were similar to those observed during ischemia, with a slight increase at the end of hour 2. There were no significant differences between hours 1, 2, and 3. Polymorphonuclear neutrophil recruitment occurred at the beginning of reperfusion (P=.014), but no significant differences were observed at hours 2 or 3. Progressive thickening of alveolar septa and edema was documented. Changes in IL-8 mRNA expression during ischemia precede interstitial infiltration by polymorphonuclear neutrophils during reperfusion, suggesting that the 2 processes are related. Quantification of IL-8 mRNA expression could facilitate early diagnosis of graft dysfunction.

Decreased complex III activity in mitochondria isolated from rat heart subjected to ischemia and reperfusion: role of reactive oxygen species and cardiolipin.

Reactive oxygen species (ROS) are considered an important factor in ischemia-reperfusion injury to cardiac myocites. We have examined the effects of ischemia (30 min) and ischemia followed by reperfusion (15 min) of rat hearts on the activity of complex III and on the cardiolipin content in isolated mitochondria. Mitochondrial production of H2O2 and lipid peroxidation was also measured. The capacity of mitochondria to produce both H2O2 and lipid peroxidation increased upon reperfusion. The activity of complex III was 22% and 46% lower in ischemic and reperfused rat heart mitochondria, respectively, than that of controls. These changes in complex III activity were associated to parallel changes in state 3 respiration. The mitochondrial content of cardiolipin, which is required for optimal activity of complex III, decreased by 28% and by 50% as a function of ischemia and reperfusion, respectively. The lower complex III activity in mitochondria from reperfused rat hearts could be completely restored to the level of normal hearts by exogenously added cardiolipin. It is proposed that the loss of complex III activity in reperfused rat hearts can be mainly ascribed to a loss of cardiolipin content, due to oxidative attack by oxygen free radicals.

Effect of Lazaroid U-74389G on Pulmonary Ischemia - Reperfusion Injury in Dogs

Lipid peroxidation induced by oxygen free radicals is a contributing factor in ischemia-reperfusion injury. Lazaroid U-74389G (LAZ-G) is a group of new synthetic 21-aminosteroids and inhibits irondependent lipid peroxidation. We investigated the effects of LAZ-G on pulmonary ischemia-reperfusion injury in dogs. Twenty dogs were divided into three groups. In the LAZ-G group (

Ionic and metabolic imbalance as potential factors of ischemia reperfusion injury

This study examined the influence of metabolic substrates on the effects of trimetazidine on functional and metabolic aspects of the ischemic reperfused heart. Isovolumic rat hearts were submitted to a 30-minute period of global mild ischemia (coronary flow decreased by an average of 70%) and then reperfused at constant preischemic coronary flow rate. Either glucose (11 m M) or glucose and palmitic acid (0.1 m M) were used as metabolic substrates. Trimetazidine (6 × 10 −7 M) markedly reduced the increase in diastolic pressure that occurred on reperfusion after the ischemic episode, whatever the exogenous substrate used. However, in those hearts that received fatty acid, the postischemic increase in diastolic pressure was abolished. Ischemia-induced increase in acyl carnitine levels—determined as indicators of fatty acid utilization by myocardial cells—was significantly decreased by trimetazidine in those hearts receiving fatty acid. Also, similar effects to those of trimetazidine on the postischemic increase in diastolic pressure and on tissue levels of acyl carnitine were obtained in the presence of dichloroacetate. Moreover, the presence of trimetazidine was associated with a reduction in the intracellular pH decrease during ischemia in those hearts receiving fatty acid. Combined with previous studies, these results suggest that an improved metabolic balance by trimetazidine may well consequently decrease the ionic imbalance after a transient period of ischemia.

Role of Endogenous Nitric Oxide in Ischemia-Reperfusion Injury in Rat Liver

Evidence has accumulated that oxygen-derived free radicals contribute to the cellular damage induced by ischemia-reperfusion. It has been suggested that nitric oxide (NO) may act as a protective factor in ischemia-reperfusion injury since NO increases blood flow and may scavenge oxyradicals. Nevertheless, controversy exists as to the role of NO. This study was designed to clarify the role of endogenous NO in ischemia-reperfusion-induced liver injury in rats in vivo. Wistar rats weighing 250-300g were divided into three groups: (1) untreated group (Control); (2) N -G nitro- l-arginine, a specific inhibitor of NO production (LNNA); and (3) l-arginine-pretreated L-NNA group (AR+L-NNA). Occlusion of all vessels to the median and left hepatic lobes (60 min) was followed by reperfusion for 1 or 24 hr. L-NNA was administered before ischemia as a 10 mg/kg bolus. l-Arginine was given just before L-NNA administration as a 100 mg/kg bolus. Administration of L-NNA resulted in endothelial cell injury characterized by the elevation of serum hyaluronic acid as well as the reduction of hepatic tissue blood flow, and the recovery of hepatic adenosine triphosphate was depressed compared with the control after both 1 and 24 hr of reperfusion. Furthermore, the leakages of various liver enzymes and lipid peroxide were also increased, associated with histological damage. This effect of L-NNA was completely abolished by pretreatment with l -arginine. These results suggest that endogenous NO provides a protective effect against ischemia-reperfusion injury in rat liver.

Clastogenic factor in ischemia-reperfusion injury during open-heart surgery: Protective effect of allopurinol

The hypothesis tested was that free radicals generated following ischemia and reperfusion in cardiac operations can produce clastogenic factor that results in chromosomal aberration.Fourteen randomized patients undergoing coronary artery bypass grafting were divided into two groups. In Group 1 (7 patients), myocardial protection was achieved using a cardioplegic solution without allopurinol. In Group 2 (7 patients), 100 mg of allopurinol (xanthine oxidase inhibitor) was added to the solution. In both groups, blood samples were taken from the coronary sinus before the aorta was clamped and 20 minutes after myocardial reperfusion was achieved. The blood samples were used to study the patients' chromosomes. The results were given as the percentage of chromosomal aberrations observed in 100 mitoses. There were no significant differences between the preischemic values in both groups and the postischemic values in Group 2. On the other hand, there was a significant difference between the postischemic values in Groups 1 and 2 (p < 0.01).In conclusion, reperfusion following myocardial ischemia in cardiac operations can produce clastogenic aberrations. This clastogenic activity can be reduced by adding allopurinol to the cardioplegic solution.

Changes in calcium content of the liver during hepatic ischemia-reperfusion in dogs

Alteration of calcium metabolism in cells has been thought to be one of the main factors in ischemia-reperfusion injury. Serial changes in the tissue calcium content of the liver and the correlation between calcium level and liver injury were investigated. Experimental dogs were divided into two groups and subjected to hepatic ischemia of different duration: 60 min in Group A and 120 min in Group B, followed by reperfusion. Serum alanine aminotransferase, as an indicator of liver injury, was more elevated in Group B than in Group A. There was no change in hepatic calcium content during ischemia in either group. Immediately after reperfusion, there was no change in hepatic calcium level in Group A, whereas in Group B it was markedly elevated. The peak value occurred 30 min after reperfusion and gradually decreased thereafter, but did not return to pre-ischemic levels during the observation time. Plasma calcium concentrations in hepatic venous blood were markedly decreased in Group B 30 min and 60 min after reperfusion. These results suggest that calcium accumulation in the liver during the early reperfusion period may be one of the mediators of hepatic injury. To elucidate the mechanisms for elevation of calcium in hepatic tissue, serum malondialdehyde, a product of lipid peroxidation, was measured in hepatic venous blood. No elevation of serum malondialdehyde was observed in either group, indicating that the increases in calcium may not be due to oxidative stress. Serum mitochondrial aspartate aminotransferase and electron microscopic findings were used as indicators of mitochondrial injury.(ABSTRACT TRUNCATED AT 250 WORDS)