Role of P-selectin and anti-P-selectin monoclonal antibody in apoptosis during hepatic/renal ischemia-reperfusion injury

AIM To evaluale the potential role of P-selectinand anti-P-selectin monoclonal antibody(mAb)in apoptosis during hepatic/renal ischemia-reperfusion injury.METHODS Plasma P-selectin level,hepatic/renal P-selectin expression and cell apoptosiswere detected in rat model of hepatic/ renalischemia-reperfusion injury.ELISA,immunohist-ochemistry and TUNEL were used.Someischemia-reperfusion rats were treated with anti-P-selectin mAb.RESULTS Hepatic/renal function insuffic-iency,up-regulated expression of P-selectin inplasma and hepatic/renal tissue,hepatic/renalhistopathological damages and cell apoptosiswere found in rats with hepatic/renal ischemia-reperfusion injury,while these changes becameless conspicuous in animals treated with anti-P-selectin mAb.CONCLUSION P-selectin might mediateneutrophil infiltration and cell apoptosis andcontribute to hepatic/renal ischemia-reperfusioninjury,anti-P-selectin mAb might be an efficientapproach for the prevention and treatment ofhepatic/renal ischemia-reperfusion injury.

New progress in roles of nitric oxide during hepatic ischemia reperfusion injury

Hepatic ischemia reperfusion injury (HIRI) is a clinical condition which may lead to cellular injury and organ dysfunction. The role of nitric oxide (NO) in HIRI is complicated and inconclusive. NO produced by endothelial nitric oxide synthase (eNOS) activation plays a protective role during early HIRI. But eNOS overexpression and the resulting excessive NO bioavailability can aggravate liver injury. NO induced by inducible nitric oxide synthase (iNOS) may have either a protective or a deleterious effect during the early phase of HIRI, but it may protect the liver during late HIRI. Here, we reviewed the latest findings on the role of NO during HIRI: (1) NO exerts a protective effect against HIRI by increasing NO bioavailability, downregulating p53 gene expression, decreasing inflammatory chemokines, reducing ROS via inhibiting the mitochondrial respiratory chain, activating sGC-GTP-cGMP signal pathway to reduce liver cell apoptosis, and regulating hepatic immune functions; (2) eNOS protects against HIRI by increasing NO levels, several eNOS/NO signal pathways (such as Akt-eNOS/NO, AMPK-eNOS/NO and HIF-1 alpha-eNOS/NO) participating in the anti-HIRI process, and inhibiting over-expression of eNOS also protects against HIRI; and (3) the inhibition of iNOS prevents HIRI. Thus, the adverse effects of NO should be avoided, but its positive effect in the clinical treatment of diseases associated with HIRI should be recognized.

miR-30b inhibits autophagy to alleviate hepatic ischemiareperfusion injury via decreasing the Atg12-Atg5 conjugate

AIM: To explore the role and potential mechanism of miR-30 b regulation of autophagy in hepatic ischemiareperfusion injury(IRI).METHODS: An animal model of hepatic IRI was generated in C57BL/6 mice. For in vitro studies, AML12 cells were immersed in mineral oil for 1 h and then cultured in complete Dulbecco's Modified Eagle's Medium(DMEM)/F12 to simulate IRI. Mice and cells were transfected with miR-30 b agomir/mimics or antagomir/inhibitor to examine the effect of miR-30 b on autophagy to promote hepatic IRI. The expression of miR-30 b was measured by real-time polymerase chain reaction. Apoptotic cells were detected by terminal uridine nickend labeling(TUNEL) staining, and cell viability was detected by methylthiazole tetrazolium assay. The expression of light chain 3, autophagy-related gene(Atg)12, Atg5, P62, and caspase-3 were detected by western blotting analysis.RESULTS: miR-30 b levels were significantly downregulated after hepatic IRI, and the numbers of autophagosomes were increased in response to IRI both in vivo and in vitro. These findings demonstrate that low levels of miR-30 b could promote hepatic IRI. Furthermore, we found that miR-30 b interacted with Atg12-Atg5 conjugate by binding to Atg12. Overexpression of miR-30 b diminished Atg12 and Atg12-Atg5 conjugate levels, which promoted autophagy in response to IR. In contrast, downregulation of miR-30 b was associated with increased Atg12-Atg5 conjugate levels and increased autophagy.CONCLUSION: miR-30 b inhibited autophagy to alleviate hepatic ischemia-reperfusion injury via decreasing the Atg12-Atg5 conjugate.

Morphological alterations and redox changes associated with hepatic warm ischemia-reperfusion injury

AIM To study the effects of warm ischemia-reperfusion(I/R) injury on hepatic morphology at the ultrastructural level and to analyze the expression of the thioredoxin(TRX)and glutaredoxin(GRX) systems.METHODS Eleven patients undergoing liver resection were subjected to portal triad clamping(PTC). Liver biopsies were collected at three time points; first prior to PTC(baseline), 20 min after PTC(post-ischemia) and 20 min after reperfusion(post-reperfusion). Electron microscopy and morphometry were used to study and quantify ultrastructural changes, respectively. Additionally, gene expression analysis of TRX and GRX isoforms was performed by quantitative PCR. For further validation of redox protein status, immunogold staining was performed for the isoforms GRX1 and TRX1.RESULTS Post-ischemia, a significant loss of the liver sinusoidal endothelial cell(LSEC) lining was observed(P = 0.0003) accompanied by a decrease of hepatocyte microvilli in the space of Disse. Hepatocellular morphology was well preserved apart from the appearance of crystalline mitochondrial inclusions in 7 out of 11 patients. Postreperfusion biopsies had similar features as post-ischemia with the exception of signs of a reactivation of the LSECs. No changes in the expression of redox-regulatory genes could be observed at mR NA level of the isoforms of the TRX family but immunoelectron microscopy indicated a redistribution of TRX1 within the cell.CONCLUSION At the ultrastructural level, the major impact of hepatic warm I/R injury after PTC was borne by the LSECs with detachment and reactivation at ischemia and reperfusion, respectively. Hepatocytes morphology were well preserved. Crystalline inclusions in mitochondria were observed in the hepatocyte after ischemia.

Mechanisms of hepatic ischemia/reperfusion injury and clinical anesthesia-related protections

This review focuses on the mechanisms involved in hepatic ischemia-reperfusion(I/R) injury and effective therapeutic treatments associated with clinical anesthesia. Although hepatocytes are the main target cells in the whole process of I/R injury, Kupffer cells, as an initiator of harmful cascades, may play a vital role by releasing some proinflammatory mediators and reactive oxygen species in the early phase of I/R injury. The subsequent activation and recruitment of neutrophils are also involved in inflammatory response and immune activation. According to the above mechanisms, a number of strategies have been put forward in some experimental and clinical studies. Most of these therapeutic treatments originated from the generation of oxygen radicals and cytokines, the infiltration of neutrophils, the impairment of microcirculation and so on. Furthermore, increasing evidence has suggested that short periods of ischemic preconditioning have protective effects against liver I/R injury. Depending on these investigations, pharmacological preconditioning and clinical anesthesia-related effective methods have been proposed. A better understanding of the present progress on experimental statistics will bring about novel therapeutic treatments for the improvement of liver surgeries and transplantation.

Effects of 2-APB on Store-operated Ca^(2+) Channel Currents of Hepatocytes after Hepatic Ischemia/Reperfusion Injury in Rats

The effects of hepatic ischemia/reperfusion (I/R) injuries on hepatocellular viability and store-operated calcium current (Isoc) in isolated rat hepatocytes and the effects of 2-APB on store-operated calcium current (Isoc) in isolated rat hepatocytes after hepatic ischemia/reperfusion injuries were studied. Hepatic ischemia and reperfusion injury model was established and whole cell patch-clamp techniques were used to investigate the effects of 2-APB on Isoc. The results showed that ischemia/reperfusion injuries could significantly reduce hepatocellular viability and further increase Isoc in hepatocytes and 2-APB (20, 40, 60, 80, 100 μmol/L) produced a concentration-dependent decrease of Isoc with IC 50 value of 64.63±10.56 μmol/L (n=8). It was concluded that ischemia/reperfusion injuries could reduce hepatocellular viability, probably through increased Isoc in hepatocytes and 2-APB had a protective effect on ischemia/reperfusion-induced liver injury, probably though inhibiting Isoc.

Expression of Toll-like Receptor 2/4 on Alveolar Macrophage in the Model of Total Hepatic Ischemia/Reperfusion Injury in Mice

Objective： To explore the expression and meaning of Toll-like receptor 2/4 in alveolar macrophage during the process of total hepatic ischemia in mice. Methods： BALB/c mice were used in a model of total hepatic ischemia/reperfusion. Alveolar Macrophage were collected at the time point of lh, 6h and 12h by the means of bronchoalveolar lavage （BAL）, and its TLR2/4 mRNA and protein were detected with Flow Cytometry and Real-time PCR. The level of TNF in BAL fluid were measured. The concentration of MPO, the ratio of wet/dry and lung histological scores were used to assess the degrees of lung injuries. Results： At the three time points of hepatic ischemia reperfusion, the expression of TLR2/4 protein of and mRNA were up-regulated and the level of TLR2 was on the rise continually. TLR4 at the time of 6 h reached the peak value （P〈0.01）. The level of TNF-2 in BAL fluid reached the highest point at the time of 6 h （P〈0.01）. The ratio of wet/dry rose continually during hepatic ischemia reperfusion. After 1 h, the level of MPO increased rapidly. Then it reached the peak value during the period of 6 h to 12 h. Conclusion： TLR2/4 on the mice of alveolar macrophage were activated in the process of hepatic ischemia/reperfusion and involved in the injury of lung.

The protecting effects and mechanism of betaine hydrochloride on hepatic ischemia-reperfusion injury in rats

Objective To study the protecting effects and mechanism of betaine hydrochloride on hepatic ischemia-reperfusion injury in rats.Methods Fourty SD rats were randomly divided into 5 groups(8 animals in each group):sham-operated control group(A),hepatic ischemia-reperfusion group(B),200 mg·kg-1 400 mg·kg-1 800 mg·kg-1 betaine hydrochloride+hepatic ischemia-reperfusion group(C、D、E).betaine hydrochloride was administered to animals byoral route in group C、D、E for 7 days before ischemia.A、B group was administered with NS.Made the animal model of part hepatic ischemia-reperfusion.Serum alanine aminotransferase(ALT),aspartate aminotransferase(AST)levels in the blood and themalondialdehyde(MDA),superoxide dismutase(SOD),protein content in hepatic tissue were determined after the liver had been reperfused for 24 hours;the hepatic tissue was examined under lightmicroscope and the cell apoptosis was demonstrated with flow cytometry.Results ALT,AST,MDA increased and SOD decreased significantly in B group when compared those in the A group(P<0.05),Hepatic apoptosis was significantly increased;ALT,AST,MDA decreased and SOD increased significantly in betaine hydrochloride 200 mg·kg-1(C)group when compared those in the B group(P<0.05).Hepatic apoptosis was significantly lower,The histologic changes of the liver tissue under lightmicroscope in the C group was more easer than in the I/R group(B).Conclusions Betaine hydrochloride has the ability to scavenge oxygen free radical(OFR),reduce lipid peroxidation and inhibition of apoptosis.So it can protect the rats liver damaged by ischemia-reperfusion.

Effect of notoginsenoside R1 on hepatic microcirculation disturbance induced by gut ischemia and reperfusion

AIM： To assess the effect of notoginsenoside R1 on hepatic microcirculatory disturbance induced by gut ischemia/reperfusion （I/R） in mice. METHODS： The superior mesenteric artery （SMA） of C57/BL mice was ligated for 15 min to induce gut ischemia followed by 30-rain reperfusion. In another set of experiments, R1 was continuously infused （10 mg/kg per hour） from 10 min before I/R until the end of the investigation to study the influence of R1 on hepatic microcirculatory disturbance induced by gut I/R. Hepatic microcirculation was observed by inverted microscopy, and the vascular diameter, red blood cell （RBC） velocity and sinusoid perfusion were estimated. Leukocyte rolling and adhesion were observed under a laser confocal microscope. Thirty and 60 min after reperfusion, lactate dehydrogenase （LDH）, alanine aminotransferase （ALl＇） and aspartate transaminase （AST） in peripheral blood were determined. The expression of adhesion molecules CD11b/CD18 in neutrophils and tumor necrosis factor- alpha （TNF-α）, interleukin-6 （IL-6） and monocyte chemotactic protein-1 （MCP-1） in plasma were evaluated by flow Oltometry. E-selectin and intercellular adhesion molecule-1 （ICAM-1） in hepatic tissue were examined by immunofluorescence.RESULTS： After gut I/R, the diameters of terminal portal venules and central veins, RBC velocity and the number of perfused sinusoids were decreased, while the leukocyte rolling and adhesion, the expression of E-selectin in hepatic vessels and CD18 in neutrophils, IL-6, MCP-1, LDH, ALT and AST were increased. R1 treatment attenuated these alterations except for IL-6 and MCP-1. CONCLUSION： R1 prevents I/R-induced hepatic microcirculation disturbance and hepatocyte injury, The effect of R1 is related to its inhibition of leukocyte rolling and adhesion by inhibiting the expression of E-selectin in endothelium and CD18 in neutrophils.

Nuclear factor-KB decoy oligodeoxynucleotides attenuates ischemia/reperfusion injury in rat liver graft

AIM： To evaluate the protective effect of NF-kB decoy oligodeoxynucleotides （ODNs） on ischemia/reperfusion （I/R） injury in rat liver graft. METHODS： Orthotopic syngeneic rat liver transplantation was performed with 3 h of cold preservation of liver graft in University of Wisconsin solution containing phosphorothioated double-stranded NF-kB decoy ODNs or scrambled ODNs. NF-kB decoy ODNs or scrambled ODNs were injected intravenously into donor and recipient rats 6 and 1 h before operation, respectively. Recipients were killed 0 to 16 h after liver graft reperfusion. NF-kB activity in the liver graft was analyzed by electrophoretic mobility shift assay （EMSA）. Hepatic mRNA expression of TNF-α, IFN-γ and intercellular adhesion molecule-1 （ICAM-1） were determined by semiquantitative RT-PCR. Serum levels of TNF-α and IFN-γ were measured by enzyme-linked immunosorbent assays （ELISA）. Serum level of alanine transaminase （ALT） was measured using a diagnostic kit. Liver graft myeloperoxidase （MPO） content was assessed. RESULTS： NF-kB activation in liver graft was induced in a time-dependent manner, and NF-kB remained activated for 16 h after graft reperfusion. NF-kB activation in liver graft was significant at 2 to 8 h and slightly decreased at 16 h after graft reperfusion. Administration of NF-kB decoy ODNs significantly suppressed NF-kB activation as well as mRNA expression of TNF-α, IFN-γ, and ICAM-1 in the liver graft. The hepatic NF-kB DNA binding activity [presented as integral optical density （IOD） value] in the NF-kB decoy ODNs treatment group rat was significantly lower than that of the I/R group rat （2.16±0.78 vs 36.78 ±6.35 and 3.06±0.84 vs 47.62± 8.71 for IOD value after 4 and 8 h of reperfusion, respectively, P〈0.001）. The hepatic mRNA expression level of TNF-α, IFN-γ and ICAM-1 rpresented as percent of β-actin mRNA （%）] in the NF-kB decoy ODNs treatment group rat was significantly lower than that of the I/R group rat （8.31 ±3.48 vs 46.37±10.65 and 7.46± 3.72 vs 74.82±12.25 for hepatic TNF-α mRNA, 5.58±2.16 vs 50.46±9.35 and 6.47±2.53 vs 69.72±13.41 for hepatic IFN-γ mRNA, 6.79 ±2.83 vs 46.23±8.74 and 5.28±2.46 vs 67.44±10.12 for hepatic ICAM-1 mRNA expression after 4 and 8 h of reperfusion, respectively, P〈0.001）. Administration of NF-kB decoy ODNs almost completely abolished the increase of serum level of TNF-α and IFN-γ induced by hepatic ischemia/reperfusion, the serum level （pg/mL） of TNF-α and in the NF-kB decoy ODNs treatment group rat was significantly lower than that of the I/R group rat （42.7±13.6 vs 176.7±15.8 and 48.4±15.1 vs 216.8±17.6 for TNF-α level, 31.5±12.1 vs 102.1±14.5 and 40.2±13.5 vs 118.6±16.7 for IFN-γ level after 4 and 8 h of reperfusion, respectively, P〈0.001）. Liver graft neutrophil recruitment indicated by MPO content and hepatocellular injury indicated by serum ALT level were significantly reduced by NF-kB decoy ODNs, the hepatic MPO content （A655） and serum ALT level （IU/L） in the NF-kB decoy ODNs treatment group rat was significantly lower than that of the I/R group rat （0.17±0.07 vs 1.12±0.25 and 0.46±0.17 vs 1.46±0.32 for hepatic MPO content, 71.7±33.2 vs 286.1±49.6 and 84.3±39.7 vs 467.8±62.3 for ALT level after 4 and 8 h of reperfusion, respectively, P〈0.001）. CONCLUSION： The data suggest that NF-kB decoy ODNs protects against I/R injury in liver graft by suppressing NF-kB activation and subsequent expression of proinflammatory mediators.

Heat shock pretreatment improves stem cell repair following ischemia-reperfusion injury via autophagy

AIM: To investigate whether heat shock pretreatment(HSP) improves mesenchymal stem cell(MSC) repair via autophagy following hepatic ischemia-reperfusion injury(HIRI).METHODS: Apoptosis of MSCs was induced by 250 m M hydrogen peroxide(H2O2) for 6 h. HSP was carried out using a 42 ℃ water bath for 1, 2 or 3 h. Apoptosis of MSCs was analyzed by flow cytometry, and Western blot was used to detect Bcl-2, Bax and cytochrome C expression. Autophagy of MSCs was analyzed by flow cytometry and transmission electron microscopy, and the expression of beclin Ⅰ?and LC3-Ⅱ was detected by Western blot. MSCs were labeled in vivo with the fluorescent dye, CM-Dil, and subsequently transplanted into the portal veins of rats that had undergone HIRI. Liver levels of proliferating cell nuclear antigen(PCNA) were quantified by fluorescent microscopy. Serum aminotransferase activity and the extent of HIRI were also assessed at each time point.RESULTS: HSP for 2 h reduced apoptosis of MSCs induced by H2O2 as seen by a decrease in apoptotic rate, a decrease in Bax and cytochrome C expression and an increase in Bcl-2 expression(P < 0.001). In addition, HSP for 2 h induced autophagy of MSCs exposed to H2O2 as shown by an increase in acidic vesicular organelle-positive cells, beclin 1 and LC3-Ⅱ expression, and autophagosome formation(P < 0.05). Treatment with 3-methyladenine attenuated HSPinduced autophagy and abolished the protective effects of HSP on the apoptosis of MSCs. Rapamycin failed to have additional effects on either autophagy or apoptosis compared with HSP alone. The phosphorylation of p38 MAPK was significantly elevated and the phosphorylation of m TOR was downregulated in heat shock pretreated MSCs. Treatment with the p38 MAPK inhibitor, SB203580, reduced HSP-induced autophagy in MSCs. In vivo studies showed that the transplantation of HSP-MSCs resulted in lower serum aminotransferase levels, lower Suzuki scores, improved histopathology and an increase in PCNA-positive cells(P < 0.05).CONCLUSION: HSP effectively induces autophagy following exposure to H2O2 via the p38MAPK/m TOR pathway, which leads to enhanced MSC survival and improved MSC repair following HIRI in rats.

Protection of Veratrum nigrum L.var.ussuriense Nakai alkaloids against ischemia-reperfusion injury of the rat liver

AIM： TO investigate the protective effects and possible mechanisms of Veratrum nigrum L. var. ussuriense Nakai alkaloids （VnA） on hepatic ischemia/reperfusion （I/R） injury in rats. METHODS： Forty male Wistar rats were randomly divided into four experimental groups （n = 10 in each）： （A） Control group （the sham operation group）; （8） I/R group （pretreated with normal saline）; （C） Small-dose （10 μg/kg） VnA pretreatment group; （D） Large-dose （20 μg/kg） VnA pretreatment group. Hepatic ischemia/ reperfusion （Hepatic I/R） was induced by occlusion of the portal vein and the hepatic artery for 90 min, followed by reperfusion for 240 min. The pretreatment groups were administered with VnA intraperitoneally, 30 min before surgery, while the control group and I/R group were given equal volumes of normal saline. Superoxide dismutase （SOD） activity, myeloperoxidase （MPO） activity and nitric oxide （NO） content in the liver tissue at the end of reperfusion were determined and liver function was measured. The expression of intercellular adhesion molecule-1 （ICAM-1） and E-selectin （ES） were detected by immunohistochemical examinations and Western blot analyses. RESULTS： The results showed that hepatic I/R elicited a significant increase in the plasma levels of alanine aminotransferase （ALT： 74.53 ± 2.58 IU/L vs 1512.54 ± 200.76 IU/L, P 〈 0.01） and lactic dehydrogenase （LDH： 473.48 ± 52.17 IU/L vs 5821.53 ± 163.69 IU/L, P 〈 0.01）, as well as the levels of MPO （1.97 ± 0.11 U/g vs 2.57 ± 0.13 U/g, P 〈 0.01） and NO （69.37 ± 1.52 μmol/g protein vs 78.39 ± 2.28 μmol/g protein, P 〈 0.01） in the liver tissue, all of which were reduced by pretreatment with VnA, respectively （ALT： 1512.54 ± 200.76 IU/L vs 977.93 ± 89.62 IU/L, 909.81 ± 132.76 IU/L, P 〈 0.01, P 〈 0.01; LDH： 5821.53 ± 163.69 IU/L vs 3015.44 ± 253.01 IU/L, 2448.75 ± 169.4 IU/L, P 〈 0.01, P 〈 0.01; MPO： 2.57 ± 0.13 U/g vs 2.13 ± 0.13 U/g, 2.07 ± 0.05 U/g, P 〈 0.01, P 〈 0.01; NO： 78.39 ± 2.28 μmol/g protein vs 71.11 ± 1.73 μmol/g protein, 68.58 ± 1.95 μmol/g protein, P 〈 0.05, P 〈 0.01）. The activity of SOD （361.75 ± 16.22 U/rag protein vs 263.19 ± 12.10 U/rag protein, P 〈 0.01） in the liver tissue was decreased after I/R, which was enhanced by VnA pretreatment （263.19 ± 12.10 U/rag protein vs 299.40 ± 10.80 U/rag protein, 302.09 ＋ 14.80 U/rag protein, P 〈 0.05, P 〈 0.05）. Simultaneously, the histological evidence of liver hemorrhage, polymorphonuclear neutrophil infiltration and the overexpression of ICAM-1 and E-selectin in the liver tissue were observed, all of which were attenuated in the VnA pretreated groups. CONCLUSION： The results demonstrate that VnA pretreatment exerts significant protection against hepatic I/R injury in rats. The protective effects are possibly associated with enhancement of antioxidant capacity, reduction of inflammatory responses and suppressed expression of ICAM-1 and E-selectin.

Pentoxifylline enhances the protective effects of hypertonic saline solution on liver ischemia reperfusion injury through inhibition of oxidative stress

BACKGROUND：Liver ischemia reperfusion（IR）injury triggers a systemic inflammatory response and is the main cause of organ dysfunction and adverse postoperative outcomes after liver surgery.Pentoxifylline（PTX）and hypertonic saline solution（HTS）have been identified to have beneficial effects against IR injury.This study aimed to investigate if the addition of PTX to HTS is superior to HTS alone for the prevention of liver IR injury.METHODS： Male Wistar rats were allocated into three groups. Control rats underwent 60 minutes of partial liver ischemia, HTS rats were treated with 0.4 mL/kg of intravenous 7.5% NaCl 15 minutes before reperfusion, and HPTX group were treated with 7.5% NaC1 plus 25 mg/kg of PTX 15 minutes before reperfusion. Samples were collected after reperfusion for determination of ALT, AST, TNF-α, IL-6, IL-10, mitochondrial respiration, lipid peroxidation, pulmonary permeability and myeloperoxidase. RESULTS： HPTX significantly decreased TNF-α 30 minutes after reperfusion. HPTX and HTS significantly decreased ALT,AST, IL-6, mitochondrial dysfunction and pulmonary myelo- peroxidase 4 hours after reperfusion. Compared with HTS only, HPTX significantly decreased hepatic oxidative stress 4 hours after reperfusion and pulmonary permeability 4 and 12 hours after reperfusion. CONCLUSION： This study showed that PTX added the beneficial effects of HTS on liver IR injury through decreases of hepatic oxidative stress and pulmonary permeability.

Rehmanniae Radix Praeparata aqueous extract improves hepatic ischemia/reperfusion injury by restoring intracellular iron homeostasis

Hepatic ischemia/reperfusion injury(HIRI)is a common pathophysiological condition occurring during or after liver resection and transplantation,leading to hepatic viability impairment and functional deterioration.Recently,ferroptosis,a newly recognized form of programmed cell death,has been implicated in IRI.Rehmanniae Radix Praeparata(RRP),extensively used in Chinese herbal medicine for its hepatoprotective,anti-inflammatory,and antioxidant properties,presents a potential therapeutic approach.However,the mechanisms by which RRP mitigates HIRI,particularly through the regulation of ferroptosis,remain unclear.In this study,we developed a HIRI mouse model and monocrotaline(MCT)-and erastin-induced in vitro hepatocyte injury models.We conducted whole-genome transcriptome analysis to elucidate the protective effects and mechanisms of RRP on HIRI.The RRP aqueous extract was characterized by the presence of acteoside,rehmannioside D,and 5-hydroxymethylfurfural.Our results demonstrate that the RRP aqueous extract ameliorated oxidative stress,reduced intracellular iron accumulation,and attenuated HIRI-induced liver damage.Additionally,RRP significantly inhibited hepatocyte death by restoring intracellular iron homeostasis both in vivo and in vitro.Mechanistically,the RRP aqueous extract reduced intrahepatocellular iron accumulation by inhibiting ZIP14-mediated iron uptake,promoting hepcidin-and ferroportin-mediated iron efflux,and ameliorating mitochondrial iron aggregation through upregulation of Cisd1 expression.Moreover,siRNA-mediated inhibition of hamp synergistically enhanced the RRP aqueous extract's inhibitory effect on ferroptosis.In conclusion,our study elucidates the mechanisms by which RRP aqueous extracts alleviate HIRI,highlighting the restoration of iron metabolic balance.These findings position RRP as a promising candidate for clinical intervention in HIRI treatment.

The gut microbial metabolite, 3,4-dihydroxyphenylpropionic acid, alleviates hepatic ischemia/reperfusion injury via mitigation of macrophage pro-inflammatory activity in mice

Hepatic ischemia/reperfusion injury(HIRI) is a serious complication that occurs following shock and/or liver surgery. Gut microbiota and their metabolites are key upstream modulators of development of liver injury. Herein, we investigated the potential contribution of gut microbes to HIRI.Ischemia/reperfusion surgery was performed to establish a murine model of HIRI. 16 S r RNA gene sequencing and metabolomics were used for microbial analysis. Transcriptomics and proteomics analysis were employed to study the host cell responses. Our results establish HIRI was significantly increased when surgery occurred in the evening(ZT12, 20:00) when compared with the morning(ZT0, 08:00);however, antibiotic pretreatment reduced this diurnal variation. The abundance of a microbial metabolite3,4-dihydroxyphenylpropionic acid was significantly higher in ZT0 when compared with ZT12 in the gut and this compound significantly protected mice against HIRI. Furthermore, 3,4-dihydroxyphenylpropionic acid suppressed the macrophage pro-inflammatory response in vivo and in vitro. This metabolite inhibits histone deacetylase activity by reducing its phosphorylation. Histone deacetylase inhibition suppressed macrophage pro-inflammatory activation and diminished the diurnal variation of HIRI. Our findings revealed a novel protective microbial metabolite against HIRI in mice. The potential underlying mechanism was at least in part, via 3,4-dihydroxyphenylpropionic acid-dependent immune regulation and histone deacetylase(HDAC) inhibition in macrophages.

Hepatic organ protection:From basic science to clinical practice

Hepatic ischemia and reperfusion (I/R) injury during liver surgery is still the main cause of postoperative liver failure and the subsequent rise of mortality in these patients. During the last few years, a multitude of underlying mechanisms have been extensively characterized and many different protective approaches have been evaluated under experimental conditions. Some of them have already found their way into small sized clinical trials. In this Topic Highlight series of articles, we present recent insights into promising protective concepts including the regulation and optimization of hepatic blood flow, molecular mechanisms of preconditioning and pharmacological approaches with the aim of limiting hepatic I/R injury. Leading international experts present the latest experimental evidence in their fields stressing clinically relevant ideas, which are now on the edge of entering clinical practice.

Endothelial Notch activation promotes neutrophil transmigration via downregulating endomucin to aggravate hepatic ischemia/reperfusion injury

Inflammatory leukocytes infiltration is orchestrated by mechanisms involving chemokines,selectins,addressins and other adhesion molecules derived from endothelial cells(ECs),but how they respond to inflammatory cues and coordinate leukocyte transmigration remain elusive.In this study,using hepatic ischemia/reperfusion injury(HIRI)as a model,we identified that endothelial Notch activation was rapidly and dynamically induced in liver sinusoidal endothelial cells(LSECs)in acute inflammation.In mice with EC-specific Notch activation(NICeCA),HIRI induced exacerbated liver damage.Consistently,endothelial Notch activation enhanced neutrophil infiltration and tumor necrosis factor(TNF)-αexpression in HIRI.Transcriptome analysis and further qRT-PCR as well as immunofluorescence indicated that endomucin(EMCN),a negative regulator of leukocyte adhesion,was downregulated in LSECs from NICeCA mice.EMCN was downregulated during HIRI in wild-type mice and in vitro cultured ECs insulted by hypoxia/re-oxygenation injury.Notch activation in ECs led to increased neutrophil adhesion and transendothelial migration,which was abrogated by EMCN overexpression in vitro.In mice deficient of RBPj,the integrative transcription factor of canonical Notch signaling,although overwhelming sinusoidal malformation aggravated HIRI,the expression of EMCN was upregulated;and pharmaceutical Notch blockade in vitro also upregulated EMCN and inhibited transendothelial migration of neutrophils.The Notch activation-exaggerated HIRI was compromised by blocking LFA-1,which mediated leukocyte adherence by associating with EMCN.Therefore,endothelial Notch signaling controls neutrophil transmigration via EMCN to modulate acute inflammation in HIRI.

Hepatic blood inflow occlusion without hemihepatic artery control in treatment of hepatocellular carcinoma

AIM:To investigate the clinical significance of hepatic blood inflow occlusion without hemihepatic artery control (BIOwHAC) in the treatment of hepatocellular carcinoma (HCC).METHODS:Fifty-nine patients with HCC were divided into 3 groups based on the technique used for achieving hepatic vascular occlusion:group 1,vascular occlusion was achieved by the Pringle maneuver (n=20);group 2,by hemihepatic vascular occlusion (HVO) (n=20);and group 3,by BIOwHAC (n=19).We compared the procedures among the three groups in term of operation time,intraoperative bleeding,postoperative liver function,postoperative complications,and length of hospital stay.RESULTS:There were no statistically significant differences (P > 0.05) in age,sex,pathological diagnosis,preoperative Child's disease grade,hepatic function,and tumor size among the three groups.No intraoperative complications or deaths occurrred,and there were no significant intergroup differences (P > 0.05) in intraoperative bleeding,hepatic function change 3 and 7 d after operation,the incidence of complications,and length of hospital stay.BIOwHAC and Pringle maneuver required a significantly shorter operation time than HVO;the difference in the serum alanine aminotransferase or aspartate aminotransferase levels before and 1 d after operation was more significant in the BIOwHAC and HVO groups than in the Pringle maneuver group (P < 0.05).CONCLUSION:BIOwHAC is convenient and safe;this technique causes slight hepatic ischemia-reperfusion injury similar to HVO.

Tolerance limit of rats to normothermic hepatic inflow occlusion under portal blood bypass

Objective: To evaluate the tolerance limit of rats tonormothermic hepatic inflow occlusion under portalblood bypass.Methods: A new rat model of normothermic hepaticinflow occlusion under portal blood bypass was estab-lished by clamping temporarily the pedicles of all liverlobes while the caudal lobe was kept as a passage ofthe portal blood flow. After hepatic blood flow re-stored, the caudal lobe was cut off. On the 7th postop-erative day, survival rate, hepatic morphological changes,and the severity and reversibility of the injured energymetabolism of the liver were investigated.Results: All rats that had been subjected to 30, 60 and90 minutes of hepatic inflow occlusion under portalblood bypass survived on the 7th postoperativeday. Ischemia-reperfusion injury of the liver was re-versible and compensatory in rats with hepatic inflowocclusion within 90minutes. However, the survivalrates of rats with 100, 110 and 120 minutes of hepaticinflow occlusion were 50%, 30% and 20% respective-ly. Liver injury of rats with 120 minutes of hepatic in-flow occlusion was severe and irreversible.Conclusions: The tolerance limit of rats to normother-mic hepatic inflow occlusion is enhanced significantlyunder portal blood bypass and the upper limit is 90minutes.