Liver Ischemia-reperfusion Injury Research Articles

Gastrodin Pretreatment Protects Liver Against Ischemia-Reperfusion Injury via Activation of the Nrf2/HO-1 Pathway.

Hepatic ischemia-reperfusion (IR) injury remains the major cause of liver damage post-liver surgery or transplantation. Diminishing oxidative stress and inflammatory responses is a powerful channel to reduce the rate of morbidity and mortality. Gastrodin (GSTD), a bioactive compound extracted from the traditional Chinese herbal agent with a long history of clinical application in nervous system diseases, is suggested to possess anti-oxidative effects on liver diseases, such as nonalcoholic fatty liver disease. However, the therapeutic potential of GSTD in liver IR injury remains unclear. In this paper, we performed surgery to set up the 70% hepatic IR injury models in mice after a three-day pretreatment of GSTD. We found the administration of GSTD reduced liver damage, which correlated with lower histological Suzuki's score, lower serum alanine transaminase (AST) and alanine transaminase (ALT) levels, less oxidative stress, and cell apoptosis in a dose-responsive manner, as compared to the parallel control. Meanwhile, we observed a great induction of heme oxygenase-1 (HO-1) and an activation of the p38 mitogen-activated protein kinases/nuclear factor erythroid 2-related factor 2 (p38MAPK/Nrf2) pathway in response to the GSTD pretreatment, while the protective effects upon GSTD diminished in mice with HO-1 heterozygous mutation. In addition, GSTD inhibited IR induced toll-like receptor (TLR) 4, but not TLR2 in a HO-1 dependent manner, leading to a down-regulation of cytokines, such as interleukin (IL)-6 and TNF-[Formula: see text]. Collectively, our findings revealed GSTD attenuated liver IR injury via activation of the HO-1 pathway, providing a novel therapeutic strategy to minimize the IR induced oxidative stress in the process of liver transplantation.

A combination of levosimendan and N-Acetylcysteine shows significant favorable efficacy on experimental liver ischemia/reperfusion injury.

Ischemia-reperfusion injury (IRI) is cellular damage that emerges from re-oxygenation of a hypoxic organ. In the present study, we aimed to examine the effects of a combination of levosimendan, an inotropic agent, and N-Acetylcysteine, the precursor of antioxidants and glutathione, in an experimental liver IRI model. In this study, 38 rats were randomly divided into five groups. Before the ischemia, study arms were given physiological saline solution, N-Acetylcysteine (NAS), levosimendan or a combination of NAS+levosimendan in a predetermined amount and duration, and the infusion was continued until the end of this study. The hepatic pedicle was occluded using an atraumatic vein clamp, and 60 minutes of ischemia was achieved. The clamp was then opened and 60 minutes of reperfusion was ensured. Liver tissue samples were obtained after sacrifice, and tissue malondialdehyde (MDA) and myeloperoxidase (MPO) levels were determined. Serum Tumor Necrosis Factor (TNF)-α, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and MPO levels of blood samples were also measured. Among the histopathological changes in the liver tissue after IRI, differences between groups were statistically significant in the injury scoring system based on congestion, vacuolization and necrosis levels. Histopathological injury score, plasma MPO, AST, ALT, tissue MPO and tissue MDA values were statistically significantly lower in the treatment groups, prominently in the levosimendan and NAS combination group concerning liver histopathological damage. The use of a levosimendan plus NAS combination in liver IRI markedly suppressed inflammation and oxidative stress and significantly reduced liver ischemia-reperfusion injury and can be recommended for decreasing IRI instead of single agent use of levosimendan or NAS.

Hypothermic oxygenated machine perfusion enables 24-hour Ex situ preservation of porcine donation after circulatory death livers

Background: End-ischemic hypothermic oxygenated machine perfusion reduces ischemia-reperfusion injury of donor livers during storage and transplantation. However, it is unknown whether this technique also supports an extension of the ex situ preservation time. We aimed to determine whether liver grafts from donation after circulatory death (DCD) porcine donors can be effectively preserved up to 24-hours using dual hypothermic oxygenated machine perfusion (DHOPE). Methods Porcine DCD livers were subjected to 2h static cold storage (SCS), followed by 2, 6, or 24 hours DHOPE (n=6 per group), using Belzer UW solution. Hepatocellular and bile duct viability were tested during 4h normothermic ex situ reperfusion with autologous blood. DCD livers preserved by 24h SCS (n=2) served as controls. Results: In all three study groups, portal venous and arterial flows remained stable during DHOPE. After normothermic reperfusion, there were no significant differences in lactate clearance, blood pH, glucose, and alanine aminotransferase levels among the DHOPE-preserved levels. All DHOPE-preserved livers produced bile and there were no significant differences in biliary pH, HCO3-, and LDH between the groups at 4h after reperfusion. Moreover, levels of malondialdehyde and HMGB-1 (markers for oxidative stress) in serum and liver parenchyma were similar for all DHOPE-preserved livers. Levels of cell-free DNA, a marker of cell death, were similar between the groups. Histological analysis of bile ducts and liver parenchyma also revealed no differences. In contrast, liver preserved by 24h SCS did not produce bile after reperfusion and turned bluish with reducing portal and arterial flows, representative for a non-viable liver. Histology revealed massive cellular necrosis. Conclusion: While 24h SCS preservation of DCD liver grafts lead to non-viable livers after warm reperfusion, DHOPE enabled successful ex situ preservation of donor livers up to 24h. If confirmed with human liver grafts, this technique can facilitate logistics of allocation and transplantation. Illustrative example of a porcine liver at the end of 24-hour DHOPE (A), and at the end of reperfusion after 24-hour DHOPE (B) or 24-hourSCS (C)

Pathophysiological Changes During Ischemia-reperfusion Injury in Rodent Hepatic Steatosis.

Ischemia and reperfusion injuries may produce deleterious effects on hepatic tissue after liver surgery and transplantation. The impact of ischemia-reperfusion injury (IRI) on the liver depends on its substrate, the percentage of liver ischemic tissue subjected to IRI and the ischemia time. The consequences of IRI are more evident in pathologic liver substrates, such as steatotic livers. This review is the result of an extended bibliographic PubMed search focused on the last 20 years. It highlights basic differences encountered during IRI in lean and steatotic livers based on studies using rodent experimental models. The main difference in cell death between lean and steatotic livers is the prevalence of apoptosis in the former and necrosis in the latter. There are also major changes in the effect of intracellular mediators, such as TNFα and IL-1β. Further experimental studies are needed in order to increase current knowledge of IRI effects and relevant mechanisms in both lean and steatotic livers, so that new preventive and therapeutic strategies maybe developed.

Protective effects of hydrogen on oxidative stress and liver function during CO2 pneumoperitoneum in dogs

The purpose of this study was to investigate the protective effects of hydrogen reducing ischemia-reperfusion injury during CO2 pneumoperitoneum on oxidative stress and liver function. Eighteen healthy Beagle dogs were divided into three groups. Dogs in the control group were subjected only to anesthesia for 90 min. The pneumoperitoneum group was subjected to the pressure of CO2 pneumoperitoneum with 12 mmHg intraabdominal pressure for 90 min. The hydrogen group was subjected to the pressure of CO2 pneumoperitoneum with 12 mmHg intra-abdominal pressure for 90 min after a subcutaneous injection of hydrogen gas (0.2 mL/kg) for 10 min. Blood samples were collected before the induction of pneumoperitoneum, as well as 2 h and 6 h after deflation, to evaluate oxidative stress and liver function in serum. Liver tissue samples were taken 6 h after deflation for histopathological examination. In comparison with group P, a milder histopathological change was found in group H2, and the levels of hepatic function and anti-oxidation in group H2 were higher. Hydrogen gas reduced liver ischemia-reperfusion injury due to CO2 pneumoperitoneum by reducing oxidative stress and improving liver function. Hydrogen gas therapy can be considered as a way to reduce liver ischemiareperfusion injury in laparoscopic surgery.

Serum Irisin Predicts Posthepatectomy Complications in Patients with Hepatocellular Carcinoma.

Background Hepatectomy remains one of the most effective treatments for patients with hepatocellular carcinoma (HCC); however, it can lead to serious complications. Irisin, a key regulator of energy metabolism, is secreted into the circulation by shedding of the extracellular portion of the fibronectin type III domain-containing 5 (FNDC5). We have shown that irisin administration alleviates liver ischemia-reperfusion injury in mice. However, the role of preoperative irisin levels in HCC patients who underwent hepatectomy remained unknown. The purpose of this study was to determine how irisin expression changes in HCC and to explore the relationship between preoperative serum irisin levels and complications after hepatectomy. Methods FNDC5/irisin expression data in HCC were extracted from The Cancer Genome Atlas (TCGA) dataset. A total of 219 participants, including 102 healthy controls and 117 HCC patients, were recruited in this study. All HCC patients underwent hepatectomy at the First Affiliated Hospital of the Xi'an Jiaotong University. Preoperative serum irisin levels were measured by ELISA. Postoperative complications were assessed using the comprehensive complication index (CCI) score. The Pearson rank correlation coefficient was computed to assess the correlation between preoperative serum irisin levels and postoperative CCI scores. Results In TCGA dataset, FNDC5/irisin expression was downregulated in HCC tissues (P < 0.001). Similarly, serum irisin levels were decreased in HCC patients (P < 0.001). Low preoperative serum irisin levels were significantly correlated with high CCI scores after hepatectomy. Conclusions Irisin may be a novel serum biomarker in the diagnosis of HCC and a predictor of complications after hepatectomy.

Effect of sevoflurane maintenance anesthesia on liver ischemia-reperfusion injury in patients undergoing partial hepatectomy

Objective To investigate the effect of sevoflurane anesthesia on hepatic ischemia-reperfusion injury in patients undergoing partial hepatectomy. Methods A total of 86 patients undergoing partial hepatectomy were divided into sevoflurane group and isoflurane group according to random number table with 43 patients in each group. Both groups received continuous epidural block combined with general anesthesia, sevoflurane group took sevoflurane combined with remifentanil to maintain anesthesia, while isoflurane group took isoflurane remifentanil to maintain anesthesia. The mean arterial pressure (MAP) and heart rate(HR) of different moments, awakening (open-eye time, extubation time, listening to instruction time, orientation recovery time, time of Aldrete score up to 9 minutes), the serum levels of tumor necrosis factor alpha (TNF-α), interleukin 1 (IL-1), aspartate aminotransferase (AST), alanine aminotransferase (ALT), glutamate dehydrogenase (GLDH), alpha glutathione S transferase (α-GST) levels at different moments were compared between the two groups. Results The MAP and HR at T1, T2, T3 and T4 in both groups were significantly lower than those at T0 (P<0.05). The HR at T1 and T4 in sevoflurane group were significantly higher than those in isoflurane group (P<0.05). The open-eye time, extubation time, listening to instruction time, orientation recovery time in sevoflurane group were significantly shorter than the isoflurane group (P<0.05). The levels of serum TNF-α, IL-1, AST, ALT, GLDH and α-GST in the two groups at T2 and T3 were significantly higher than those at T0 (P<0.05), and began to fall back to T4. The levels of serum TNF-α, IL-1, AST, ALT, GLDH and α-GST in the sevoflurane group at T2 and T3 were significantly lower than those in the isoflurane group (P<0.05). Conclusions The hepatic hemodynamics in patients undergoing partial hepatectomy with sevoflurane is more stable better than isoflurane during operation, which has faster postoperative recovery and relieved hepatic ischemia-reperfusion injury. Key words: Hepatectomy; Sevoflurane; Reperfusion injury; Hemodynamics

Renalase Attenuates Mouse Fatty Liver Ischemia/Reperfusion Injury through Mitigating Oxidative Stress and Mitochondrial Damage via Activating SIRT1.

Liver ischemia/reperfusion (IR) injury is a severe complication of liver surgery. Moreover, nonalcoholic fatty liver disease (NAFLD) patients are particularly vulnerable to IR injury, with higher rates of postoperative morbidity and mortality after liver surgeries. Our previous study found that renalase (RNLS) was highly sensitive and responsive to oxidative stress, which may be a promising biomarker for the evaluation of the severity of liver IR injury. However, the role of RNLS in liver IR injury remains unclear. In the present study, we intensively explored the role and mechanism of RNLS in fatty liver IR injury in vivo and in vitro. C57BL/6 mice were divided into 2 groups feeding with high-fat diet (HFD) and control diet (CD), respectively. After 20 weeks' feeding, they were suffered from portal triad blockage and reflow to induce liver IR injury. Additionally, oleic acid (OA) and tert-butyl hydroperoxide (t-BHP) were used in vitro to induce steatotic hepatocytes and to simulate ROS burst and mimic cellular oxidative stress following portal triad blockage and reflow, respectively. Our data showed that RNLS was downregulated in fatty livers, and RNLS administration effectively attenuated IR injury by reducing ROS production and improving mitochondrial function through activating SIRT1. Additionally, the downregulation of RNLS in the fatty liver was mediated by a decrease of signal transduction and activator of transcription 3 (STAT3) expression under HFD conditions. These findings make RNLS a promising therapeutic strategy for the attenuation of liver IR injury.

Ischemia reperfusion injury promotes recurrence of hepatocellular carcinoma in fatty liver via ALOX12-12HETE-GPR31 signaling axis

BackgroundIschemia reperfusion injury (IRI) has been shown to increase the risk of tumor recurrence after liver surgery. Also, nonalcoholic fatty liver disease (NAFLD) is associated with increased HCC recurrence. ALOX12–12-HETE pathway is activated both in liver IRI and NASH. Also, ALOX12–12-HETE has been shown to mediate tumorigenesis and progression. Therefore, our study aims to investigate whether the ALOX12–12-HETE-GPR31 pathway involved in IRI induced HCC recurrence in NAFLD.MethodsHCC mouse model was used to mimic the HCC recurrence in NAFLD. Western Blot, qPCR, Elisa and Immunofluorescence analysis were conducted to evaluate the changes of multiple signaling pathways during HCC recurrence, including ALOX12–12-HETE axis, EMT, MMPs and PI3K/AKT/NF-κB signaling pathway. We also measured the expression and functional changes of GPR31 by siRNA.ResultsALOX12–12-HETE pathway was activated in liver IRI and its activation was further enhanced in NAFLD, which induced more severe HCC recurrence in fatty livers than normal livers. Inhibition of ALOX12–12-HETE by ML355 reduced the HCC recurrence in fatty livers. In vitro studies showed that 12-HETE increased the expression of GPR31 and induced epithelial-mesenchymal transition (EMT) and matrix metalloprotein (MMPs) by activating PI3K/AKT/NF-κB pathway. Furthermore, knockdown of GPR31 in cancer cells inhibited the HCC recurrence in NAFLD.ConclusionsALOX12–12-HETE-GPR31 played an important role in HCC recurrence and might be a potential therapeutic target to reduce HCC recurrence after surgery in fatty livers.

RNA interference therapeutics in organ transplantation: The dawn of a new era.

RNA interference (RNAi) is a natural process through which double-stranded RNA molecules can silence the gene carrying the same code as the particular RNA of interest. In 2006, the discovery of RNAi was awarded the Nobel Prize in Medicine and its success has accumulated since. Gene silencing through RNAi has been used successfully in a broad range of diseases, and, more recently, this technique has gained interest in the field of organ transplantation. Here, genes related to ischemia-reperfusion injury (IRI) or graft rejection may be silenced to improve organ quality after transplantation. Several strategies have been used to deliver siRNA, and pretransplant machine perfusion presents a unique opportunity to deliver siRNA to the target organ during ex situ preservation. In this review, the potential of RNAi in the field of organ transplantation will be discussed. A brief overview on the discovery of RNAi, its mechanism, and limitations are included. In addition, studies using RNAi to target genes related to IRI in liver, kidney, lung, and heart transplantation are discussed.

Advances in intervention measures for hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury is an inevitable clinical phenomenon during the liver transplantation. The mechanism of hepatic ischemia-reperfusion injury is complex, with reactive oxygen species, inflammatory factors, calcium overload, neutrophils and Kupffer cells involved. If injury continues to getting worsen, liver cells will undergo necrosis, apoptosis, and autophagy. Interventions for hepatic ischemia-reperfusion injury mainly include ischemic preconditioning, drug pretreatment, chemical pretreatment, mild hypothermia pretreatment, and machine perfusion and gene-targeted therapy in recent years. With the indepth research of injury mechanism, new intervention methods continue to emerge, which will bring new ideas for clinical prevention and treatment of liver ischemia-reperfusion injury. Key words: Liver; Reperfusion injury; Intervention

Pan-caspase inhibitor F573 mitigates liver ischemia reperfusion injury in a murine model.

BackgroundLiver ischemia reperfusion injury (IRI) remains a challenge in liver transplantation. A number of compounds have previously demonstrated efficacy in mitigating IRI. Herein, we applied three specific additive strategies to a mouse IRI screening model to determine their relative potencies in reducing such injury, with a view to future testing in a large animal and clinical ex situ normothermic perfusion setting: 1) F573, a pan-caspase inhibitor, 2) anti-inflammatory anakinra and etanrecept and 3) BMX-001, a mimetic of superoxide dismutase.MethodsA non-lethal liver ischemia model in mice was used. Additives in the treatment groups were given at fixed time points before induction of injury, compared to a vehicle group that received no therapeutic treatment. Mice were recovered for 6 hours following the ischemic insult, at which point blood and tissue samples were obtained. Plasma was processed for transaminase levels. Whole liver tissue samples were processed for histology, markers of apoptosis, oxidative stress, and cytokine levels.ResultsIn an in vivo murine IRI model, the F573 treatment group demonstrated statistically lower alanine aminotransferase (ALT) levels (p = 0.01), less evidence of apoptosis (p = 0.03), and lower cytokine levels compared to vehicle. The etanercept with anakinra treatment group demonstrated significantly lower cytokine levels. The BMX-001 group demonstrated significantly decreased apoptosis (p = 0.01) evident on TUNEL staining.ConclusionsThe administration of pan-caspase inhibitor F573 in a murine in vivo model likely mitigates liver IRI based on decreased markers of cellular injury, decreased evidence of apoptosis, and improved cytokine profiles. Anakinra with etanercept, and BMX-001 did not demonstrate convincing efficacy at reducing IRI in this model, and likely need further optimization. The positive findings set rational groundwork for future translational studies of applying F573 during normothermic ex situ liver perfusion, with the aim of improving the quality of marginal grafts.

Tissue Inhibitor of Metalloproteinase 3 Deficiency Disrupts the Hepatocyte E-Cadherin/β-Catenin Complex and Induces Cell Death in Liver Ischemia/Reperfusion Injury.

Tissue inhibitor of metalloproteinase (TIMP) 3 is a naturally occurring inhibitor of a broad range of proteases, with key roles in extracellular matrix turnover and in the pathogenesis of various diseases. In this study, we investigated the response of mice lacking TIMP3 (TIMP3-/-) to hepatic ischemia/reperfusion injury (IRI). We report here that TIMP3-/- mice showed an enhanced inflammatory response, exacerbated organ damage, and further impaired liver function after IRI when compared with their wild-type littermates. Loss of TIMP3 led to the cleavage and shedding of E-cadherin during hepatic IRI; the full-length 120-kDa E-cadherin and the ratio of 38-kDa C-terminal fragment/120-kDa E-cadherin were decreased and increased, respectively, in TIMP3-/- livers after IRI. Moreover, GI254023X, a potent inhibitor of a disintegrin and metalloprotease (ADAM) 10, was capable of partially rescuing the expression of E-cadherin in the TIMP3-null hepatocytes. The proteolysis of E-cadherin in the TIMP3-/- livers was also linked to the loss of β-catenin from the hepatocyte membranes and to an increased susceptibility to apoptosis after liver IRI. In a similar fashion, depression of the E-cadherin/β-catenin complex mediated by TIMP3 deletion and knockdown of β-catenin by small interfering RNA were both capable of inducing caspase activation in isolated hepatocytes subjected to H2 O2 oxidative stress. Hence, these results support a protective role for TIMP3 expression in sheltering the hepatocyte E-cadherin/β-catenin complex from proteolytic processing and inhibiting apoptosis after hepatic IRI.

Hepatocellular HO-1 mediated iNOS-induced hepatoprotection against liver ischemia reperfusion injury

Hepatocyte-derived inducible nitric oxide synthase (iNOS) was proved to impart protection against liver ischemia reperfusion (I/R) injury in our prior analysis. However, the mechanism for this hepatoprotection remains incompletely understood. Bone marrow chimeric mice were generated using expression of iNOS in a hepatocyte-selective manner against an iNOS-knockout background. The function of heme oxygenase 1 (HO-1) in iNOS-stimulated hepatoprotection and the molecular mechanisms were explored in vitro and in vivo, respectively. Hepatocyte-derived iNOS conferred protection from I/R injury and anoxia/reoxygenation stimulation. Mechanistically, iNOS activated nuclear factor erythroid 2-related factor 2 (Nrf-2) and subsequently, stimulated the transcription of HO-1. Results from our study led to the conclusion that HO-1 is another potent mediator of iNOS-mediated protection after liver I/R.

Protective Role of mTOR in Liver Ischemia/Reperfusion Injury: Involvement of Inflammation and Autophagy.

Liver ischemia/reperfusion (IR) injury is a common phenomenon after liver resection and transplantation, which often results in liver graft dysfunction such as delayed graft function and primary nonfunction. The mammalian target of rapamycin (mTOR) is an evolutionarily highly conserved serine/threonine protein kinase, which coordinates cell growth and metabolism through sensing environmental inputs under physiological or pathological conditions, involved in the pathophysiological process of IR injury. In this review, we mainly present current evidence of the beneficial role of mTOR in modulating inflammation and autophagy under liver IR to provide some evidence for the potential therapies for liver IR injury.

Jagged1-mediated myeloid Notch1 signaling activates HSF1/Snail and controls NLRP3 inflammasome activation in liver inflammatory injury

Notch signaling plays important roles in the regulation of immune cell functioning during the inflammatory response. Activation of the innate immune signaling receptor NLRP3 promotes inflammation in injured tissue. However, it remains unknown whether Jagged1 (JAG1)-mediated myeloid Notch1 signaling regulates NLRP3 function in acute liver injury. Here, we report that myeloid Notch1 signaling regulates the NLRP3-driven inflammatory response in ischemia/reperfusion (IR)-induced liver injury. In a mouse model of liver IR injury, Notch1-proficient (Notch1FL/FL) mice receiving recombinant JAG1 showed a reduction in IR-induced liver injury and increased Notch intracellular domain (NICD) and heat shock transcription factor 1 (HSF1) expression, whereas myeloid-specific Notch1 knockout (Notch1M-KO) aggravated hepatocellular damage even with concomitant JAG1 treatment. Compared to JAG1-treated Notch1FL/FL controls, Notch1M-KO mice showed diminished HSF1 and Snail activity but augmented NLRP3/caspase-1 activity in ischemic liver. The disruption of HSF1 reduced Snail activation and enhanced NLRP3 activation, while the adoptive transfer of HSF1-expressing macrophages to Notch1M-KO mice augmented Snail activation and mitigated IR-triggered liver inflammation. Moreover, the knockdown of Snail in JAG1-treated Notch1FL/FL livers worsened hepatocellular functioning, reduced TRX1 expression and increased TXNIP/NLRP3 expression. Ablation of myeloid Notch1 or Snail increased ASK1 activation and hepatocellular apoptosis, whereas the activation of Snail increased TRX1 expression and reduced TXNIP, NLRP3/caspase-1, and ROS production. Our findings demonstrated that JAG1-mediated myeloid Notch1 signaling promotes HSF1 and Snail activation, which in turn inhibits NLRP3 function and hepatocellular apoptosis leading to the alleviation of IR-induced liver injury. Hence, the Notch1/HSF1/Snail signaling axis represents a novel regulator of and a potential therapeutic target for liver inflammatory injury.

Dual roles of immune cells and cytokines in hepatic ischemia reperfusion injury

Ischemia-reperfusion injury is one of the main causes of complications related to liver transplantation, hepatectomy, trauma and hemorrhagic shock. The cells of ischemia and hypoxic injury release of injury-related molecular patterns, lead to the activation of immune cells and cytokine, which further aggravates the inflammatory response and enlarges the injury. It’s indicated that injury-related molecular patterns, liver resident immune cells and cytokines play a key role in promoting inflammation and liver ischemia-reperfusion injury. However, recent studies suggested that the ischemia cells and cytokines played acomplex role in this process. Relevant progresses were reviewed in this article. Key words: Reperfusion injury; Liver; Cytokines; High mobility group protein B1; Dendritic cells

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.

Gadolinium chloride alleviates partial warm ischemia-reperfusion injury of liver by suppressing kupffer cell function in mice

Objective To investigate the effect and mechanism of gadolinium chloride alleviates partial warm ischemia-reperfusion injury of liver by suppressing kupffer cell function in mice. Methods Forty-eight male C57BL/6 mice were randomly divided into sham-operated group (Sham), Hepatic ischemia-reperfusion injury (HIRI) group, gdolinium chloride groups (Gd+ IRI), and cobalt protoporphyrin (CoPP+ IRI) group (n=12). The rats were injected with the same dose of normal saline in Sham group and IRI group. Gd+ IRI group were intraperitoneally injected with GdCl3 (20 mg/kg) 24 hours before operation. At the same time, CoPP+ IRI group were intraperitoneally injected with CoPP (5 mg/kg). Except for Sham group, an 70% volume HIRI model was established by means of 60 minutes ischemia and then 6 hours reperfusion in the other groups. The levels of serum aspartate transaminase (AST) and alanine aminotransferase (ALT) in each group were compared. Enzyme-linked immunosorbent assay were used to test the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in the liver tissue. The level of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, heme oxygenase-1 (HO-1), and protective factor IL-10 mRNA level were detected by real time quantitative polymerase Chain Reaction (RT-PCR). Immunohistochemical staining was used to measure Fas, FasL protein expression level of extrahepatic biliary epithelial cells. Results Respectively, the serum ALT level in the HIRI, Gd+ IRI and CoPP+ IRI groups was (1 236.7±62.4), (638.9±50.9), (740.3±53.1) U/L, and the AST level was (1 107.8±68.3), (568.5±42.7), (679.1±49.9) U/L, the serum level of ALT and AST in Gd+ IRI and CoPP+ IRI groups was lower than IRI group (t=6.721, P<0.01; t=4.732, P<0.05; t=5.984, P<0.01; t=2.691, P<0.05). Compared with IRI group, the activity of SOD and GSH-Px was promoted (t=7.301, P<0.01; t=1.937, P<0.05), whereas the levels of MDA was reduced (t=9.519, P<0.01; t=8.635, P<0.01). Simultaneously, the TNF-α, IL-1β and IL-6 mRNA level in Gd+ IRI and CoPP+ IRI groups were decreased (t=6.721, P<0.01; t=2.316, P<0.05), and the levels of IL-10 and HO-1 mRNA were increased (t=2.973, P<0.05; t=7.921, P<0.01). After hepatic artery reflow 6 h, the Fas expression levels on bile ducts epithelial cells in Gd+ IRI and CoPP+ IRI groups respectively was 22.4%, 29.7%, which was lower than IRI group (38.9%) (χ2=6.561, P<0.01; χ2=2.547, P<0.05). The FasL expression levels in Gd+ IRI and CoPP+ IRI groups respectively was 21.2%, 25.1%, which was lower than IRI group (36.5%) (χ2=5.982, P<0.05; χ2=3.188, P<0.05). Conclusion Gdolinium chloride shows an protective function aganist liver ischemia-reperfusion iniury in mice by Oxidative stress, inhibiting inflammation and cell apoptosis. The up-regulation of HO-1 by gdolinium chloride may be the possible mechanism. The up-regulation of HO-1 and inhibiting the Fas/FasL protein expression by gdolinium chloride may be the possible mechanism. Key words: Gdolinium chloride; Liver; Ischemia-reperfusion injury; Heme oxygenase-l

Ex Situ Liver Machine Perfusion as an Emerging Graft Protective Strategy in Clinical Liver Transplantation: the Dawn of a New Era.

The disparity between the number of available donor livers and patients awaiting a liver transplant has led transplant centers to accept suboptimal livers. There has been no universally accepted tool to predict the posttransplant function of these organs to safely increase the donor pool, protect these livers against ischemia-reperfusion injury, or improve their quality before implantation. Ex situ liver machine preservation has emerged as a promising novel graft protective strategy in the field of liver transplantation, with remarkable ongoing research and evolving clinical trials within Europe and the United States. This technology has been shown to be safe and feasible in the clinical liver transplantation field, has shown to reduce liver ischemia-reperfusion injury, and has shown to decrease the graft discard rate compared with conventional static cold storage. This review focuses on the current status of ex situ machine preservation in clinical liver transplantation, describing the most important technical aspects with the emphasis on the findings of the most recent clinical studies.