Reduce Ischemia-reperfusion Injury Research Articles

Abstract 355: Effect of Poloxamer 188 on Rat Brain Isolated Mitochondria After Exposure to Hydrogen Peroxide

Introduction: In a pig model of myocardial infarction (MI), intracoronary delivered Poloxamer (P) 188 significantly reduces ischemia/reperfusion (IR) injury when given immediately upon reperfusion, with improved mitochondrial function as a predominant effect. As mitochondria are heavily damaged during IR, a direct effect of P188 on mitochondria may lead to better therapy options during reperfusion. To show not only a similar reduction of IR injury by P188 in the brain, but also a direct P188 effect on mitochondria, we established an in-vitro model of IR that consists of damaging isolated rat brain mitochondria with hydrogen peroxide (H 2 O 2 ), one component of ischemia, then applying P188, and analyzing mitochondrial function. Methods: Male Sprague-Dawley rat brains were removed, and the mitochondria isolated by differential centrifugation and Percoll gradients, then kept on ice to slow their bioenergetics prior to any experimental treatments. Mitochondria were exposed to 200 μM H 2 O 2 for 10 min at room temperature with slight agitation; controls received no H 2 O 2 . Samples were then diluted ½ with buffer ± P188 (250 μM after dilution) to simulate reperfusion and treatment, and kept at room temperature for 10 further minutes. ATP synthesis was measured in a luminometer using a luciferase enzymatic assay. Oxygen consumption was measured by closed cell respirometry with an oxygen meter. In both assays, Complex I and Complex II were examined; Complex I substrates glutamate and malate, Complex II substrate succinate plus the Complex I inhibitor rotenone. Statistics: Data are expressed as mean ± SEM. One-Way ANOVA, SNK-Test; Kruskal-Wallis-Test; α=0.05, * vs control. Results: In both Complex I and II, mitochondrial function was significantly impaired by H 2 O 2 , with ATP synthesis affected more at Complex I and oxygen consumption affected more at Complex II. Addition of P188 did not provide any significant improvement in mitochondrial function. Conclusions: Although P188 significantly reduced IR injury when given during reperfusion in a pig model of MI, it does not appear to provide direct protection to mitochondria in this in-vitro model. Whether the exposure to H 2 O 2 causes the appropriate injury for P188 to become effective remains to be elucidated.

Augmenter of Liver Regeneration Reduces Ischemia Reperfusion Injury by Less Chemokine Expression, Gr-1 Infiltration and Oxidative Stress.

Hepatic ischemia reperfusion injury (IRI) is a major complication in liver resection and transplantation. Here, we analyzed the impact of recombinant human augmenter of liver regeneration (rALR), an anti-oxidative and anti-apoptotic protein, on the deleterious process induced by ischemia reperfusion (IR). Application of rALR reduced tissue damage (necrosis), levels of lipid peroxidation (oxidative stress) and expression of anti-oxidative genes in a mouse IRI model. Damage associated molecule pattern (DAMP) and inflammatory cytokines such as HMGB1 and TNFα, were not affected by rALR. Furthermore, we evaluated infiltration of inflammatory cells into liver tissue after IRI and found no change in CD3 or γδTCR positive cells, or expression of IL17/IFNγ by γδTCR cells. The quantity of Gr-1 positive cells (neutrophils), and therefore, myeloperoxidase activity, was lower in rALR-treated mice. Moreover, we found under hypoxic conditions attenuated ROS levels after ALR treatment in RAW264.7 cells and in primary mouse hepatocytes. Application of rALR also led to reduced expression of chemo-attractants like CXCL1, CXCL2 and CCl2 in hepatocytes. In addition, ALR expression was increased in IR mouse livers after 3 h and in biopsies from human liver transplants with minimal signs of tissue damage. Therefore, ALR attenuates IRI through reduced neutrophil tissue infiltration mediated by lower expression of key hepatic chemokines and reduction of ROS generation.

Investigation of the underlying hub genes and mechanisms of reperfusion injury in patients undergoing coronary artery bypass graft surgery by integrated bioinformatic analyses.

Although coronary artery bypass graft (CABG) surgery is the main method to revascularize the occluded coronary vessels in coronary artery diseases, the full benefits of the operation are mitigated by ischemia-reperfusion (IR) injury. Although many studies have been devoted to reducing IR injury in animal models, the translation of this research into the clinical field has been disappointing. Our study aimed to explore the underlying hub genes and mechanisms of IR injury. A weighted gene co-expression network analysis (WGCNA) was executed based on the expression profiles in patients undergoing CABG surgery (GSE29396). Functional annotation and protein-protein interaction (PPI) network construction were executed within the modules of interest. Potential hub genes were predicted, combining both intramodular connectivity (IC) and degrees. Meanwhile, potential transcription factors (TFs) and microRNAs (miRNAs) were predicted by corresponding bioinformatics tools. A total of 336 differentially expressed genes (DEGs) were identified. DEGs were mainly enriched in neutrophil activity and immune response. Within the modules of interest, 5 upregulated hub genes (IL-6, CXCL8, IL-1β, MYC, PTGS-2) and 6 downregulated hub genes (C3, TIMP1, VSIG4, SERPING1, CD163, and HP) were predicted. Predicted miRNAs (hsa-miR-333-5p, hsa-miR-26b-5p, hsa-miR-124-3p, hsa-miR-16-5p, hsa-miR-98-5p, hsa-miR-17-5p, hsa-miR-93-5p) and TF (STAT1) might have regulated gene expression in the most positively related module, while hsa-miR-333-5p and HSF-1 were predicted to regulate the genes within the most negatively related module. Our study illustrates an overview of gene expression changes in human atrial samples from patients undergoing CABG surgery and might help translate future research into clinical work.

An evaluation of rivaroxaban and clopidogrel in a rat lower extremity ischemia-reperfusion model: An experimental study.

This study aims to compare clopidogrel and rivaroxaban against ischemia-reperfusion injury after a long reperfusion time and to investigate its effects on various tissues. A total of 40 Wistar rats were included in the study and were randomly divided into four groups (n=10 per group). Groups were defined as follows: control (Group 1), sham (Group 2), clopidogrel pre-treatment (Group 3), and rivaroxaban pre-treatment (Group 4). Ischemia (6 h) and reperfusion (8 h) were induced at the lower hind limb in Groups 2, 3, and 4. The ischemic muscle, heart, kidney, liver, and plasma tissues of the subjects were obtained to test for the oxidant (malondialdehyde) and antioxidants (glutathione, superoxide dismutase, and nitric oxide). Malondialdehyde levels were significantly higher in the sham group, compared to the controls in all tissues. Clopidogrel and rivaroxaban pre-treatment significantly decreased malondialdehyde levels, compared to the heart, ischemic muscle, liver, and blood tissues of the sham group. Kidney malondialdehyde levels were reduced only by rivaroxaban. Group 4 had significantly decreased malondialdehyde levels, compared to Group 3 in ischemic muscle (p<0.010). The glutathione reduction, compared to sham group, in the kidney was only significant for Group 4 (p<0.050). With clopidogrel and rivaroxaban pretreatment, nitric oxide levels significantly decreased only in the heart tissue, compared to sham group (p<0.001 and p<0.050, respectively). The study results suggest that rivaroxaban and clopidogrel are effective in reducing ischemia-reperfusion injury in the heart, ischemic muscle, liver, and blood. Rivaroxaban also protects the kidneys and is superior to clopidogrel in ischemic muscle protection.

Protective effect and mechanism of alpha-lipoic acid on partial hepatic ischemia-reperfusion injury in adult male rats.

In order to reduce tissue damage caused by ischemia-reperfusion injury, this study aims to investigate the protective effect and mechanism of ?-lipoic acid on hepatic ischemia-reperfusion injury in rats. The bloodstream of rats was blocked in the left middle and left lateral liver lobes of the liver. Forty rats were randomly divided into two groups: treatment group and injury group. Rats were injected with either 25 mg/1 ml of alpha-lipoic acid (treatment group) or 1 ml of saline (injury group) into the caudal vein 15 min before hepatic ischemia-reperfusion. Rat serum alanine aminotransferase (GPT), glutathione (GSH) and superoxide dismutase (SOD) levels were examined at various time points (1, 3, 6 and 12 h) in both groups. Changes in nuclear factor kappa B P65 (NF-kappaB P65) expression in ischemia-reperfusion liver at various time points after reperfusion (1, 3, 6 and 12 h) were evaluated through immunohistochemistry assay. Changes in macrophage inflammatory protein-2 (MIP-2) mRNA and inducible nitric oxide synthase (iNOS) mRNA expression in ischemic reperfused rat livers were detected by RT-PCR. Serum GPT level was significantly higher in the injury group than in the treatment group (P<0.01). NF-kappaB P65, MIP-2 mRNA and iNOS mRNA expression in ischemic reperfused rat livers were significantly higher in the injury group than in the treatment group (P<0.01). Serum GSH and SOD levels were higher in the treatment group than in the injury group (P<0.01). Alpha-lipoic acid significantly reduced ischemia-reperfusion injury in rat livers. This may be associated to the direct scavenging of oxygen-free radicals, increased GSH production, and the activation of downstream media due to decreased NF-kappaB and GSH consumption.

Carthamin Yellow Protects the Heart Against Ischemia/Reperfusion Injury With Reduced Reactive Oxygen Species Release and Inflammatory Response.

Carthamin yellow (CY) is a flavonoid compound isolated from safflower, which is widely used clinically in China. It has various pharmacological effects including promoting blood circulation to remove blood stasis and alleviating pain. Ischemic heart disease is one of the main culprits of illness and death. Here, in this study, ex vivo and in vivo models were used to investigate whether CY reduces ischemia/reperfusion injury. In vitro experiments further verify and explain the potential mechanisms of CY cardioprotective function. Isolated hearts from male rats with or without CY pretreatment before ischemia which underwent 30-minute ischemia followed by 60-minute reperfusion showed that CY pretreatment significantly reduced the infarct size and lactate dehydrogenase release. The in vivo experiments also indicated CY preadministration (i.v.) reduced infarct size and improved the heart function, which was impaired by myocardial ischemia/reperfusion injury. The in vitro model on myocardial cell also showed that CY reduced ischemia/reperfusion injury by reducing the lactate dehydrogenase and reactive oxygen species (ROS) releasing. Eliminating ROS with N-acetylcysteine or preinject CY into rat jugular vein reduces the expression of IL-6, TNF-a, and, especially, IL-1b in an in vivo I/R model. Also, CY pretreatment strongly reduces ischemia/reperfusion-induced NLRP3 up-expression and caspase-1 activation. Our results indicated CY reduced ischemia-reperfusion injury when administered before reperfusion. The reduction in injury is accompanied by a reduced ROS release and decreased inflammatory response.

Roles of pyroptosis in myocardial ischemia/reperfusion injury diseases

Ischemia-reperfusion injury (IRI) occurred when an organ lost its blood supply in a short . After that, the perfusion the perfusion was restored automatically or iatrogenically, leading to a burst of reactive oxygen species (ROS) from mitochondria. It is common in the clinic, resulting in lead to deterioration, even death, so an exploratory examination of the mechanism of ischemia-reperfusion injury is of great significance. Among the most common and fatal types of IR in myocardial tissue, myocardial IRI is one of the most fatal diseases in the modern world. The cellular and molecular mechanisms of IRI mainly include calcium overload, oxidative stress, endoplasmic reticulum (ER) stress, mitochondrial dysfunction, energy metabolic disorders, neutrophil infiltration, cardiomyocyte autophagy, and apoptosis, etc. The main pathogenesis of IRI is programmed cell death, of which apoptosis is the most deeply studied processes. pyroptosis is a highly inflammatory form of programmed cell death (PCD), which depends on the activation of the caspase cascade and inflammatory mediators, which have been thought to be involved in the processes of IRI. Ptosis has been referred to as a pattern. PCD with apoptosis characteristics Necrosis. It’s stimulated by molecular signaling pathways similar to apoptosis, mainly including Caspase. The research progress in recent years is presented in this review. Among them, myocardial tissue and so on provide a theoretical basis for the burning organ system in I/R injury and provide theoretical practice for the clinical research of reducing ischemia-reperfusion injury.

Safety and Efficacy of Treprostinil (Remodulin®) In Reducing Ischemia-Reperfusion Injury During Kidney Transplantation

Safety and Efficacy of Treprostinil (Remodulin®) In Reducing Ischemia-Reperfusion Injury During Kidney Transplantation

The efficacy of ketamine supplementation on pain management for knee arthroscopy: A meta-analysis of randomized controlled trials.

Introduction:The efficacy of ketamine supplementation on pain management for knee arthroscopy remains controversial. We conduct a systematic review and meta-analysis to explore the influence of ketamine supplementation for knee arthroscopy.Methods:We search PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through October 2018 for randomized controlled trials (RCTs) assessing the effect of ketamine supplementation on pain control for knee arthroscopy. This meta-analysis is performed using the random-effect model.Results:Seven RCTs involving 300 patients are included in the meta-analysis. Overall, compared with control group for knee arthroscopy, ketamine supplementation reveals favorable impact on pain scores (mean difference [MD] = –2.95; 95% confidence interval [CI] = –3.36 to –2.54; P < .00001), analgesic consumption (standard mean difference [Std. MD] = –1.03; 95% CI = –1.70 to –0.36; P = .002), time to first analgesic requirement (Std. MD = 1.21; 95% CI = 0.45–1.96; P = .002) and malondialdehyde (Std. MD = –0.63; 95% CI = –1.05 to 3.10; P = –.20), and shows no increase in nausea and vomiting (RR = 1.87; 95% CI = 0.65–3.10; P = .003).Conclusions:Ketamine supplementation benefits to pain management and may reduce ischemia reperfusion injury in patients with knee arthroscopy.

Ischemic Preconditioning and Iloprost Reduces Ischemia-Reperfusion Injury in Jejunal Flaps: An Animal Model.

Free jejunal flaps are among the most commonly used flaps for esophageal reconstruction. However, ischemia-reperfusion injury caused by warm ischemia seen during transfer limits their use. Iloprost, a prostacyclin analogue, has been shown to reduce ischemia-reperfusion injury in various organs. The authors investigated tissue damage in jejunal flaps with iloprost and ischemic preconditioning and compared the effectiveness of these two modalities. Thirty-four Sprague-Dawley rats were randomized into five groups: sham, ischemia-reperfusion (control), ischemic preconditioning, iloprost, and ischemic preconditioning plus iloprost. All flaps, except those in the sham group, underwent ischemia for 60 minutes and reperfusion for 2 hours. Flap perfusion was assessed by laser Doppler perfusion monitoring. Histologic sections were scored using the Chiu scoring system. Superoxide dismutase and myeloperoxidase levels were measured spectrophotometrically. Animals that were administered iloprost and/or underwent ischemic preconditioning had better postischemic recovery of mesenteric perfusion (ischemic preconditioning, 78 percent; iloprost, 83 percent; ischemic preconditioning plus iloprost, 90 percent; versus ischemia-reperfusion, 50 percent; p < 0.05). All intervention groups showed improved histology of jejunal flaps following ischemia-reperfusion injury (ischemic preconditioning, 3; iloprost, 2.3; ischemic preconditioning plus iloprost, 3.2; versus ischemia-reperfusion, 4.7; p < 0.01, p < 0.001, and p < 0.05, respectively). Superoxide dismutase levels were higher in ischemic preconditioning, iloprost plus ischemic preconditioning, and iloprost groups (ischemic preconditioning, 2.7 ± 0.2; ischemic preconditioning plus iloprost, 2.5 ± 0.3; versus ischemia-reperfusion, 1.2 ± 0.1; p < 0.01; iloprost, 2.4 ± 1.1; versus ischemia-reperfusion, 1.2 ± 0.1; p < 0.05). Myeloperoxidase, a marker for neutrophil infiltration, was lower in the iloprost group (iloprost, 222 ± 5; versus ischemia-reperfusion, 291 ± 25; p < 0.05). This study showed that both iloprost and ischemic preconditioning reduced reperfusion injury in jejunal flaps. Based on histologic results, iloprost may be a novel treatment alternative to ischemic preconditioning.

Discussion: Ischemic Preconditioning and Iloprost Reduces Ischemia-Reperfusion Injury in Jejunal Flaps: An Animal Model.

Discussion: Ischemic Preconditioning and Iloprost Reduces Ischemia-Reperfusion Injury in Jejunal Flaps: An Animal Model.

Hypothermic Oxygenated Machine Perfusion of Liver Grafts from Brain-Dead Donors

Hypothermic oxygenated machine perfusion (HOPE) was introduced in liver transplantation (LT) to mitigate ischemia-reperfusion injury. Available clinical data mainly concern LT with donors after circulatory-determined death, whereas data on brain-dead donors (DBD) are scarce. To assess the impact of end-ischemic HOPE in DBD LT, data on primary adult LTs performed between March 2016 and June 2018 were analyzed. HOPE was used in selected cases of donor age >80 years, apparent severe graft steatosis, or ischemia time ≥10 hours. Outcomes of HOPE-treated cases were compared with those after static cold storage. Propensity score matching (1:2) and Bayesian model averaging were used to overcome selection bias. During the study period, 25 (8.5%) out of 294 grafts were treated with HOPE. After matching, HOPE was associated with a lower severe post-reperfusion syndrome (PRS) rate (4% versus 20%, p = 0.13) and stage 2–3 acute kidney injury (AKI) (16% versus 42%, p = 0.046). Furthermore, Bayesian model averaging showed lower transaminases peak and a lower early allograft dysfunction (EAD) rate after HOPE. A steeper decline in arterial graft resistance throughout perfusion was associated with lower EAD rate. HOPE determines a significant reduction of ischemia reperfusion injury in DBD LT.

Which agent should be used to reduce ischemia-reperfusion injury after testicular torsion: a comparative animal experiment

Testicular torsion is an acute urological emergency that causes severe damage of testis. In order to prevent testicular damage, early diagnosis and surgical intervention is essential. Also pain management in both pre-operative and postoperative periods remains a challenging entity. In this study, we aimed to determine the possible positive effects of three different analgesics (ibuprofen, metamizole, and paracetamol), which are widely used in clinical practice on testicular tissue, in addition to pain control. Forty prepubertal rats (180-210g) were divided into five experimental groups. Group 1 was sham group in which the left testis was brought out through a scrotal incision and then replaced in the scrotum without torsion. Group 2 was control group (only 0.9% NaCl was applied). Also in group 3, paracetamol, in group 4, ibuprofen, and in group 5, metamizole sodium was applied 1h after the torsion. Torsion duration was planned as 4h for all groups. In the biochemical evaluation, malondialdehyde (MDA), myeloperoxidase (MPO), and total nitrate (NO) levels were measured in the testicular tissue. All groups were compared with group 2 (control group). In group 3, although the MDA level was lowerand the MPO level was found to be higher, these were not statistically significant. In group 4, the NO level was low but statistically significant. Histological findings were evaluated due to Cosentino's classification, and the scores of group 4 were better than all groups. In this study, severe damage was observed at the end of torsion period of 4h. This is in line with previous published data. The beneficial effects of all three drugs have been observed. Biochemical results did not clearly highlight any agents. According to pathology results, metamizole was better than paracetamol and the most ideal analgesic preparation was observed as ibuprofen.

Serp-2, a virus-derived apoptosis and inflammasome inhibitor, attenuates liver ischemia-reperfusion injury in mice

BackgroundIschemia-reperfusion injury (IRI) is an antigen-independent, innate immune response to arterial occlusion and ischemia with subsequent paradoxical exacerbation after reperfusion. IRI remains a critical problem after vessel occlusion and infarction or during harvest and surgery in transplants. After transplant, liver IRI (LIRI) contributes to increased acute and chronic rejection and graft loss. Tissue loss during LIRI has been attributed to local macrophage activation and invasion with excessive inflammation together with hepatocyte apoptosis and necrosis. Inflammatory and apoptotic signaling are key targets for reducing post-ischemic liver injury.Myxomavirus is a rabbit-specific leporipoxvirus that encodes a suite of immune suppressing proteins, often with extensive function in other mammalian species. Serp-2 is a cross-class serine protease inhibitor (serpin) which inhibits the inflammasome effector protease caspase-1 as well as the apoptotic proteases granzyme B and caspases 8 and 10. In prior work, Serp-2 reduced inflammatory cell invasion after angioplasty injury and after aortic transplantation in rodents. In this report, we explore the potential for therapeutic treatment with Serp-2 in a mouse model of LIRI.MethodsWildtype (C57BL/6 J) mice were subjected to warm, partial (70%) hepatic ischemia for 90 min followed by treatment with saline or Serp-2 or M-T7, 100 ng/g/day given by intraperitoneal injection on alternate days for 5 days. M-T7 is a Myxomavirus-derived inhibitor of chemokine-GAG interactions and was used in this study for comparative analysis of an unrelated viral protein with an alternative immunomodulating mechanism of action. Survival, serum ALT levels and histopathology were assessed 24 h and 10 days post-LIRI.ResultsSerp-2 treatment significantly improved survival to 85.7% percent versus saline-treated wildtype mice (p = 0.0135), while M-T7 treatment did not significantly improve survival (p = 0.2584). Liver viability was preserved by Serp-2 treatment with a significant reduction in serum ALT levels (p = 0.0343) and infarct scar thickness (p = 0.0016), but with no significant improvement with M-T7 treatment. Suzuki scoring by pathologists blinded with respect to treatment group indicated that Serp-2 significantly reduced hepatocyte necrosis (p = 0.0057) and improved overall pathology score (p = 0.0046) compared to saline. Immunohistochemistry revealed that Serp-2 treatment reduced macrophage infiltration into the infarcted liver tissue (p = 0.0197).ConclusionsTreatment with Serp-2, a virus-derived inflammasome and apoptotic pathway inhibitor, improves survival after liver ischemia-reperfusion injury in mouse models. Treatment with a cross-class immune modulator provides a promising new approach designed to reduce ischemia-reperfusion injury, improving survival and reducing chronic transplant damage.

Attenuation of Cardiac Ischaemia-reperfusion Injury by Treatment with Hydrogen-rich Water.

Background: Hydrogen has been shown to exert a bioactive effect on the myocardium. This study examined the signalling pathways for hydrogen attenuating ischaemia-reperfusion injury.Methods: In total, 20 male Wistar rats were evaluated for the effects of hydrogen-rich water on ischaemia-reperfusion in hearts. Left ventricular tissue was taken for screening and analysis of active protein factors by protein chip technology. The enrichment of the KEGG pathway was obtained by using the Gene Ontology (GO) enrichment principle. The expression of JAK2, STAT1, STAT3, p-STAT1, p-JAK2, p-STAT3 in rat myocardium was detected by Western blot analysis and immunohistochemistry. The apoptosis rates of the control and hydrogen-rich water groups were detected by TUNEL staining.Results: The expression levels of 25 proteins, including five transduction pathways, were downregulated in the hydrogen-rich water group. The expression levels of p-JAK2/JAK2, p-STAT3/STAT3 were upregulated in the hydrogen-rich water group compared with the control group, and p-STAT1/STAT1 was downregulated in the hydrogen-rich water group compared with the control group. Furthermore, the apoptosis rate was significantly decreased in the hydrogen-rich water group, as well.Conclusion: Hydrogen-rich water may inhibit the apoptosis of cardiomyocytes after ischaemia-reperfusion by upregulating the expression of the JAK2-STAT3 signalling pathway, which reduces ischaemia-reperfusion injury.

Cardioplegia and myocardial protection: time for a reassessment?

Since the beginnings of open cardiac surgery many different strategies have been introduced to clinical practice in order to provide a motion- and bloodless operation field. Arresting the heart with cardioplegic solutions was described by Melrose and colleagues for the first time (1). Since then cardioplegic solutions have been widely accepted as feasible and safe for the majority of cardiac operations (2). In 1981 Hearse formulated the axioms of myocardial protection during cardiac surgery: firstly cardiac arrest for the conservation of cellular energy storages; secondly hypothermia for the reduction of cellular energy demands; and thirdly application of substances to prevent or reduce ischemia-reperfusion injury (3). These axioms form the foundation for most cardioplegic solutions today.

Study protocol for a multicenter randomized controlled trial to compare the efficacy of end-ischemic dual hypothermic oxygenated machine perfusion with static cold storage in preventing non-anastomotic biliary strictures after transplantation of liver grafts donated after circulatory death: DHOPE-DCD trial

BackgroundThe major concern in liver transplantation of grafts from donation after circulatory death (DCD) donors remains the high incidence of non-anastomotic biliary strictures (NAS). Machine perfusion has been proposed as an alternative strategy for organ preservation which reduces ischemia-reperfusion injury (IRI). Experimental studies have shown that dual hypothermic oxygenated machine perfusion (DHOPE) is associated with less IRI, improved hepatocellular function, and better preserved mitochondrial and endothelial function compared to conventional static cold storage (SCS). Moreover, DHOPE was safely applied with promising results in a recently performed phase-1 study. The aim of the current study is to determine the efficacy of DHOPE in reducing the incidence of NAS after DCD liver transplantation.MethodsThis is an international multicenter randomized controlled trial. Adult patients (≥18 yrs. old) undergoing transplantation of a DCD donor liver (Maastricht category III) will be randomized between the intervention and control group. In the intervention group, livers will be subjected to two hours of end-ischemic DHOPE after SCS and before implantation. In the control group, livers will be subjected to care as usual with conventional SCS only. Primary outcome is the incidence of symptomatic NAS diagnosed by a blinded adjudication committee. In all patients, magnetic resonance cholangiography will be obtained at six months after transplantation.DiscussionDHOPE is associated with reduced IRI of the bile ducts. Whether reduced IRI of the bile ducts leads to lower incidence of NAS after DCD liver transplantation can only be examined in a randomized controlled trial.Trial registrationThe trial was registered in Clinicaltrials.gov in September 2015 with the identifier NCT02584283.

MAP4K4 Inhibition Promotes Survival of Human Stem Cell-Derived Cardiomyocytes and Reduces Infarct Size InVivo.

SummaryHeart disease is a paramount cause of global death and disability. Although cardiomyocyte death plays a causal role and its suppression would be logical, no clinical counter-measures target the responsible intracellular pathways. Therapeutic progress has been hampered by lack of preclinical human validation. Mitogen-activated protein kinase kinase kinase kinase-4 (MAP4K4) is activated in failing human hearts and relevant rodent models. Using human induced-pluripotent-stem-cell-derived cardiomyocytes (hiPSC-CMs) and MAP4K4 gene silencing, we demonstrate that death induced by oxidative stress requires MAP4K4. Consequently, we devised a small-molecule inhibitor, DMX-5804, that rescues cell survival, mitochondrial function, and calcium cycling in hiPSC-CMs. As proof of principle that drug discovery in hiPSC-CMs may predict efficacy in vivo, DMX-5804 reduces ischemia-reperfusion injury in mice by more than 50%. We implicate MAP4K4 as a well-posed target toward suppressing human cardiac cell death and highlight the utility of hiPSC-CMs in drug discovery to enhance cardiomyocyte survival.

Aryl hydrocarbon receptor pathway participates in myocardial ischemia reperfusion injury by regulating mitochondrial apoptosis

Reducing ischemia reperfusion (I/R) injury has been a major challenge in the treatment of cardiovascular disease. It is widely accepted that mitochondrial apoptosis is an important link in myocardial infarction induced by I/R damage. Studies suggested that aryl hydrocarbon receptor (AhR) pathway plays an important role in the development and function of the cardiovascular system and regulating the mitochondrial homeostasis. AhR played a critical role in regulating mitochondrial homeostasis in response to TCDD-induced stress through translocation of AhR from the cytoplasm into the cell nucleus. And a portion of AhR was found in the mitochondrial inter membrane space. Moreover, there were abundant AhR expression in myocardial cells induced by I/R, and ischaemic post-conditioning reversed apoptotic reperfusion injury involving the AhR signaling pathway. Additionally, AhR is involved in the mechanism of cardiac toxicity of many chemotherapeutic agents. Given the discovery mentioned above, we hypothesize that AhR pathway participates in myocardial ischemia reperfusion injury by regulating mitochondrial apoptosis. Meanwhile, how the AhR pathway is involved in I/R damage and regulating mitochondrial apoptosis is needed to further verified. To evaluate our hypothesis, we will measure the expression of AhR in mitochondria and cytoplasm after myocardial ischemia and reperfusion in vitro and in vivo. And then study the AhR pathway in regulating mitochondrial apoptosis to participate in myocardial I/R injury using mitochondrial protein mass spectrometry analysis and RNA interference technique. If our hypothesis is correct, AhR will be a key target in myocardial I/R injury and myocardial infarction, which could provide important agents.

Nicotinamide riboside has protective effects in a rat model of mesenteric ischaemia-reperfusion.

Acute mesenteric ischaemia is a syndrome caused by inadequate blood flow through the mesenteric vessels, resulting in ischaemia and eventual gangrene of the bowel wall. Although relatively rare, it is a potentially life-threatening condition. The maintenance of haemodynamic stability, along with adequate oxygen saturation, and the correction of any electrolyte imbalance, are of the utmost importance. However, nicotinamide adenine dinucleotide (NAD) biosynthesis modulation by precursor introduction can also be a powerful tool for preventing injury. Nicotinamide riboside is a pyridine-nucleoside form of vitamin B3 that functions as a precursor to NAD+ . The present study investigated nicotinamide riboside's effect on endothelium functional state, microcirculation and intestinal morphology in acute mesenteric ischaemia and reperfusion. Mesenteric ischaemia was simulated after the adaptation period (15minutes) by occluding the superior mesenteric artery for 60minutes, followed by a reperfusion period of 30minutes. The functional state of intestinal microcirculation was evaluated by laser Doppler flowmetry. Endothelial functional activity was studied by using wire myography. Intestinal samples were stained with haematoxylin and eosin for histological analysis. The results revealed that nicotinamide riboside protects the intestinal wall from ischaemia-reperfusion injury, as well as improving the relaxation function of mesenteric vessels. Nicotinamide riboside's protective effect in small intestine ischaemia-reperfusion can be used to reduce ischaemia-reperfusion injury, as well as to preserve intestinal grafts until transplant.