Machine perfusion of the liver: Which is the best technique to mitigate ischaemia-reperfusion injury?

Longstanding research describes the mechanisms whereby the restoration of blood flow and reoxygenation(reperfusion) aggravates the ischaemic injury caused by a period of anoxia to a donor liver. This phenomenon, called ischaemia-reperfusion injury(IRI), leads to parenchymal cell death,microcirculatory failure, and inflammatory immune response. Clinically, IRI is the main factor responsible for the occurrence of posttransplant graft dysfunction and ischaemic-type biliary lesions. While extended criteria donor livers are more vulnerable to IRI, their utilisation is required to address the shortfall in donor organs. Thus, the mitigation of IRI should drive the setting of a new benchmark for marginal organ preservation. Herein, strategies incorporating different modalities of machine perfusion of the liver to alleviate IRI are discussed in conjunction with advantages and disadvantages of individual protocols.Techniques leading to reperfusion of the liver during machine perfusion(in situ normothermic regional perfusion and ex situ normothermic machine perfusion)may mitigate IRI by shortening the ischaemic period of the organs. This benefit potentially escalates from the minimum level, obtained following just partial alleviation of the ischaemic period, to the maximum level, which can be potentially achieved with ischaemia-free organ transplantation. Techniques that do not lead to reperfusion of the liver during machine perfusion(hypothermic,subnormothermic, and controlled-oxygenated rewarming) optimise mitochondrial oxidative function and replenish cellular energy stores, thereby lowering reactive oxygen species production as well as the activation ofdownstream inflammatory pathways during reperfusion. Further mechanistic insights into IRI may guide the development of donor-specific protocols of machine perfusion on the basis of the limitations of individual categories of extended criteria donor organs.

Mechanism of acupuncture in attenuating cerebral ischaemia-reperfusion injury based on nuclear receptor coactivator 4 mediated ferritinophagy

OBJECTIVE:To explore the effect of acupuncture treatment on cerebral ischaemia-reperfusion injury(CIRI)and reveal the underlying mechanism of the effect based on nuclear receptor coactivator 4(NCOA4)mediated ferritinophagy.METHODS:Sprague-Dawley male rats were divided into four groups:the sham group,model group,acupuncture group,and sham acupuncture group.After 2 h of middle cerebral artery occlusion(MCAO),reperfusion was performed for 24 h to induce CIRI.The rats were treated with acupuncture at the Neiguan(PC6)and Shuigou(GV26)acupoints.Their neurological function was evaluated by taking their Bederson scores at 2 h after ischaemia and 24 h after reperfusion.Triphenyltetrazolium chloride staining was applied to assess the cerebral infarct volume at 24 h after reperfusion.The malondialdehyde(MDA)and ferrous iron(Fe^(2+))levels were observed after 24 h of reperfusion using an assay kit.Western blotting was performed to detect the expression of NCOA4 and ferritin heavy chain 1(FTH1)at 24 h after reperfusion.Moreover,the colocalization of ferritin with neurons,NCOA4 with microtubule-associated protein 1 light chain 3(LC3),and NCOA4 with ferritin was visualized using immunofluorescence staining.RESULTS:Acupuncture significantly improved neurological function and decreased cerebral infarct volume in the acupuncture group.Following CIRI,the expression of NCOA4,LC3 and FTH1 was increased,which enhanced ferritinophagy and induced an inappropriate accumulation of Fe^(2+)and MDA in the ischaemic brain.However,acupuncture dramatically downregulated the expression of NCOA4,LC3 and FTH1,inhibited the overactivation of ferritinophagy,and decreased the levels of MDA and Fe^(2+).CONCLUSIONS:Acupuncture can inhibit NCOA4-mediated ferritinophagy and protect neurons against CIRI in a rat model.

Literature review of the mechanisms of acute kidney injury secondary to acute liver injury

People exposed to liver ischaemia reperfusion(IR)injury often develop acute kidney injury and the combination is associated with significant morbidity and mortality.Molecular mediators released by the liver in response to IR injury are the likely cause of acute kidney injury(AKI)in this setting,but the mediators have not yet been identified.Identifying the mechanism of injury will allow the identification of therapeutic targets which may modulate both liver IR injury and AKI following liver IR injury.

Efficacy of electroacupuncture on myocardial protection and postoperative rehabilitation in patients undergoing cardiac surgery with cardiopulmonary bypass:a systematic review and Meta-analysis

OBJECTIVE:To evaluate the efficacy of electroacupuncture(EA)intervention on myocardial protection and postoperative rehabilitation in patients undergoing cardiac surgery with cardiopulmonary bypass(CPB).METHODS:Eight databases,including Pub Med,Embase,the Cochrane Library,Web of Science,Chinese Bio Medical Literature Database,China National Knowledge Infrastructure Database,Wanfang Data,China Science and Technology Journal Database,and two clinical trial registries,were searched.All randomized controlled trials(RCTs)related to EA intervention in cardiac surgery with CPB were collected.Based on the inclusion and exclusion criteria,two researchers independently screened articles and extracted data.After the quality evaluation,RevMan 5.3 software was used for analysis.RESULTS:Fourteen RCTs involving 836 patients were included.Compared with the control treatment,EA significantly increased the incidence of cardiac automatic rebeat after aortic unclamping[relative risk(RR)=1.15,95%confidence interval(CI)(1.01,1.31),P<0.05;moderate].Twenty-four hours after aortic unclamping,EA significantly increased the superoxide dismutase[standardized mean difference(SMD)=0.96,95%CI(0.32,1.61),P<0.05;low],and interleukin(IL)-2[SMD=1.33,95%CI(0.19,2.47),P<0.05;very low]expression levels and decreased the malondialdehyde[SMD=-1.62,95%CI(-2.15,-1.09),P<0.05;moderate],tumour necrosis factor-α[SMD=-1.28,95%CI(-2.37,-0.19),P<0.05;moderate],and cardiac troponin I[SMD=-1.09,95%CI(-1.85,-0.32),P<0.05;low]expression levels as well as the inotrope scores[SMD=-0.77,95%CI(-1.22,-0.31),P<0.05;high].There was no difference in IL-6 and IL-10 expression levels.The amount of intraoperative sedative[SMD=-0.31,95%CI(-0.54,-0.09),P<0.05;moderate]and opioid analgesic[SMD=-0.96,95%CI(-1.53,-0.38),P<0.05;low]medication was significantly lower in the EA group than in the control group.Moreover,the postoperative tracheal intubation time[SMD=-0.92,95%CI(-1.40,-0.45),P<0.05;low]and intensive care unit stay[SMD=-1.71,95%CI(-3.06,-0.36),P<0.05;low]were significantly shorter in the EA group than in the control group.There were no differences in the time to get out of bed for the first time,total days of antibiotic use after surgery,or postoperative hospital stay.No adverse reactions related to EA were reported in any of the included studies.CONCLUSIONS:In cardiac surgery with CPB,EA may be a safe and effective strategy to reduce myocardial ischaemia-reperfusion injury and speed up the recovery of patients after surgery.These findings must be interpreted with caution,as most of the evidence was of low or moderate quality.More RCTs with larger sample sizes and higher quality are needed to provide more convincing evidence.

Neutrophil CC1 plays a protective role in orthotopic liver transplantation: views from the perspective of natural compounds

Orthotopic liver transplantation(OLT)is the mainstay treatment for malignant liver cancer and end-stage liver diseases.Nevertheless,liver ischemia-reperfusion injury(IRI),which is regarded as a major risk factor for primary graft dysfunction,acute or chronic tissue rejection and organ damage[1],greatly limits the indication of liver resection and the application of marginal donor liver,seriously hindering the application of liver transplantation.