Polydatin ameliorates hepatic ischemia-reperfusion injury by modulating macrophage polarization

Background:Polydatin,a glucoside of resveratrol,has shown protective effects against various diseases.However,little is known about its effect on hepatic ischemia-reperfusion(I/R)injury.This study aimed to elucidate whether polydatin protects liver against I/R-induced injury and to explore the underlying mechanism.Methods:After gavage feeding polydatin once daily for a week,mice underwent a partial hepatic I/R procedure.Serum alanine aminotransferase(ALT)/aspartate aminotransferase(AST),hematoxylin-eosin(H&E)and TdT-mediated dUTP nick-end labeling(TUNEL)staining were used to evaluate liver injury.The severity related to the inflammatory response and reactive oxygen species(ROS)production was also investigated.Furthermore,immunofluorescence and Western blotting were used to detect macrophage polarization and the NF-κB signaling pathway in macrophages.Results:Compared with the I/R group,polydatin pretreatment significantly attenuated I/R-induced liver damage and apoptosis.The oxidative stress marker(dihydroethidium fluorescence,malondialdehyde,superoxide dismutase and glutathione peroxidase)and I/R related inflammatory cytokines(interleukin1β,interleukin-10 and tumor necrosis factor-α)were significantly suppressed after polydatin treatment.In addition,the result of immunofluorescence indicated that polydatin reduced the polarization of macrophages toward M1 macrophages both in vivo and in vitro.Western blotting showed that polydatin inhibited the pro-inflammatory function of RAW264.7 via down-regulating the NF-κB signaling pathway.Conclusions:Polydatin protects the liver from I/R injury by remodeling macrophage polarization via NFκB signaling.

Dynamics of glutamine synthetase expression in hepatic ischemiareperfusion injury: Implications for therapeutic interventions

BACKGROUND Hepatic ischemia-reperfusion injury(IRI)poses a great challenge in liver surgery and transplantation because of oxidative stress and inflammatory responses.The changes in glutamine synthetase(GS)expression during hepatic IRI remain unclear.AIM To investigate the dynamic expression of GS during hepatic IRI.METHODS Following hepatic ischemia for 1 h and reperfusion,liver tissue samples were collected at 0.5,6,and 24 hours postreperfusion for fixation,embedding,section-ing.Hematoxylin and eosin staining and GS staining were performed.RESULTS GS expression rapidly decreases in hepatocytes around the central vein after IRI,reaching its lowest point at 6 hours postreperfusion,and then gradually recovers.CONCLUSION GS is highly sensitive to IRI,highlighting its potential role as an indicator of liver injury states and a target for therapeutic intervention.

Surgical management in biliary restricture after Roux-en-Y hepaticojejunostomy for bile duct injury

AIM: To discuss the surgical method and skill of biliary restricture after Roux-en-Y hepaticojejunostomy for bile duct injury. METHODS: From November 2005 to December 2006, eight patients with biliary restricture after Roux-en-Y hepaticojejunostomy for bile duct injury were admitted to our hospital. Their clinical data were analyzed retrospectively. RESULTS: Bile duct injury was caused by cholecys- tectomy in the eight cases, including seven cases with laparoscopic cholecystectomy and one with mini- incision choleystectomy. According to the classification of Strasberg, type E1 injury was found in one patient, type E2 injury in three, type E3 injury in two and type E4 injury in two patients. Both of the type E4 injury patients also had a vascular lesion of the hepatic artery. Six patients received Roux-en-Y hepaticojejunostomy for the second time, and one of them who had type E4 injury with the right hepatic artery disruption received right hepatectomy afterward. One patient who had type E4 injury with the proper hepatic artery lesion underwent liver transplantation, and the remaining one with type E3 injury received external biliary drainage. All the patients recovered fairly well postoperatively. CONCLUSION: Roux-en-Y hepaticojejunostomy is still the main approach for such failed surgical cases with bile duct injury. Special attention should be paid to concomitant vascular injury in these cases. The optimal timing and meticulous and excellent skills are essential to the success in this surgery.

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.

Effect of naked eukaryotic expression plasmid encoding rat augmenter of liver regeneration on acute hepatic injury and hepatic failure in rats

AIM: To study the protective effect of eukaryotic expression plasmid encoding augmenter of liver regeneration (ALR) on acute hepatic injury and hepatic failure in rats. METHODS: The PCR-amplified ALR gene was recombined with pcDNA3 plasmid, and used to treat rats with acute hepatic injury. The rats with acute hepatic injury induced by intraperitoneal injection of 2 mL/kg 50% carbon tetrachloride (CCl4) were randomly divided into saline control group and recombinant pcDNA3-ALR plasmid treatment groups. Recombinant pcDNA3-ALR plasmid DNA (50 or 200 μg/kg) was injected into the rats with acute hepatic injury intravenously, intraperitoneally, or intravenously and intraperitoneally in combination 4 h after CCl4 administration, respectively. The recombinant plasmid was injected once per 12 h into all treatment groups four times, and the rats were decapitated 12 h after the last injection. Hepatic histopathological alterations were observed after HE staining, the expression of proliferating cell nuclear antigen (PCNA) in liver tissue was detected by immunohistochemical staining, and the level of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was determined by biochemical method. The recombinant plasmid DNA (200 μg/kg) and saline were intraperitoneally injected into the rats with acute hepatic failure induced by intraperitoneal injection of 4 mL/kg 50% CCl4 after 4 h of CCl4 administration, respectively. Rats living over 96 h were considered as survivals.RESULTS: The sequence of ALR cDNA of recombinant pcDNA3-ALR plasmid was accordant with the reported sequence of rat ALR cDNA. After the rats with acute hepatic injury were treated with recombinant pcDNA3-ALR plasmid, the degree of liver histopathological injury markedly decreased. The pathologic liver tissues, in which hepatic degeneration and necrosis of a small amount of hepatocytes and a large amount of infiltrating inflammatory cells were observed, and they became basically normal in the most effective group after four times of injection of recombinant pcDNA3-ALR plasmid. The indexes of PCNA significantly increased in the recombinant pcDNA3-ALR plasmid treatment groups compared to model group. The level of serum AST and ALT remarkably reduced in recombinant pcDNA3-ALR plasmid treatment groups compared to model group. The results showed that the effect of 200 μg/kg recombinant pcDNA3-ALR plasmid in the rats with acute liver injury was stronger than that of 50μg/kg pcDNA3-ALR DNA.The effect of intravenous injection of recombinant pcDNA3ALR plasmid was better. After the rats with acute hepatic failure were treated with recombinant pcDNA3-ALR plasmid,the survival rate (40%) significantly increased in treatment groups compared to control group (15%, P＜0.01).CONCLUSION: The ALR gene may play an important role in relieving acute hepatic injury and hepatic failure by promoting hepatic cell proliferation and reducing level ofAST and ALT in CCl4-intoxicated rats.

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.

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.

Molecular therapy for hepatic injury and fibrosis:Where are we?

Hepatic fibrosis is a wound healing response, involving pathways of inflammation and fibrogenesis. In response to various insults, such as alcohol, ischemia, viral agents, and medications or hepatotoxins, hepatocyte damage will cause the release of cytokines and other soluble factors by Kupffer cells and other cell types in the liver. These factors lead to activation of hepatic stellate cells, which synthesize large amounts of extracellular matrix components. With chronic injury and fibrosis, liver architecture and metabolism are disrupted, eventually manifesting as cirrhosis and its complications. In addition to eliminating etiology, such as antiviral therapy and pharmacological intervention, it is encouraging that novel strategies are being developed to directly address hepatic injury and fibrosis at the subcellular and molecular levels. With improvement in understanding these mechanisms and pathways, key steps in injury, signaling, activation, and gene expression are being targeted by molecular modalities and other molecular or gene therapy approaches. This article intends to provide an update in terms of the current status of molecular therapy for hepatic injury and fibrosis and how far we are from clinical utilization of these new therapeutic modalities.

Ex vivo-expanded bone marrow stem cells home to the liver and ameliorate functional recovery in a mouse model of acute hepatic injury

BACKGROUND:Stem cell transplantation provides a theoretical approach for liver regeneration medicine;it may promote liver regeneration and self-repair.However,the transplantation of bone marrow-mesenchymal stem cells expanded ex vivo as a therapy for liver disease has rarely been investigated.This study aimed to explore whether bone marrow stem cells expanded ex vivo home to the liver and foster hepatic recovery after CCl 4 injury.METHODS:Bone marrow cells from BALB/c mice were expanded ex vivo by multiple-passage cultivation,characterized by cytoflow immunofluorescence,and pre-labeled with PKH26 before intravenous infusion into animals treated with CCl 4.The integration of bone marrow cells into the liver was examined microscopically,and plasma hepatic enzymes were determined biochemically.RESULTS:Cultured bone marrow cells exhibited antigenic profiles comparable to those of primary medullary stem cells.Double immunofluorescence showed colocalization of these cells with proliferative activity and albumin expression in the liver of CCl 4 -treated mice.Densitometry showed increased in situ cell proliferation (50±14 vs 20±3 cells/high-power field,P<0.05) and albumin expression (149±25 vs 20±5 cells/high-power field,P<0.05) in the liver,as well as reduced serum aminotransferase levels (P<0.05) and better survival rates (P<0.05) in animals receiving cultured bone marrow cells relative to controls.CONCLUSIONS:Ex vivo-expanded bone marrow cells are capable of relocating to and proliferating in the chemically- injured liver.Transplantation of these pluripotent stem cells appears to improve serum indices of liver function and survival rate in mice after CCl4-induced hepatic damage.

Curcumin protects against acetaminophen-induced apoptosis in hepatic injury

AIM:To explore the effects of curcumin(CMN)on hepatic injury induced by acetaminophen(APAP)in vivo.METHODS:Male mice were randomly divided into three groups:groupⅠ(control)mice received the equivalent volumes of phosphate-buffered saline(PBS)intraperitoneally(ip);GroupⅡ[APAP+carboxymethylcellulose(CMC)]mice received 1%CMC(vehicle)2h before APAP injection;GroupⅢ(APAP+CMN)mice received curcumin(10 or 20 mg/kg,ip)2 h before before or after APAP challenge.In GroupsⅡandⅢ,APAP was dissolved in pyrogen-free PBS and injected at a single dose of 300 mg/kg.CMN was dissolved in 1%CMC.Mice were sacrificed 16 h after the APAP injection to determine alanine aminotransferase(ALT)levels in serum and malondialdehyde(MDA)accumulation,superoxide dismutase(SOD)activity and hepatocyte apoptosis in liver tissues.RESULTS:Both pre-and post-treatment with curcumin resulted in a significant decrease in serum ALT compared with APAP treatment group(10 mg/kg:801.46±661.34 U/L;20 mg/kg:99.68±86.48 U/L vs 5406.80±1785.75 U/L,P<0.001,respectively).The incidence of liver necrosis was significantly lowered in CMN treated animals.MDA contents were significantly reduced in 20 mg/kg CMN pretreatment group,but increased in APAP treated group(10.96±0.87 nmol/mg protein vs 16.03±2.58 nmol/mg protein,P<0.05).The decrease of SOD activity in APAP treatment group and the increase of SOD in 20 mg/kg CMN pretreatment group were also detected(24.54±4.95 U/mg protein vs 50.21±1.93 U/mg protein,P<0.05).Furthermore,CMN treatment efficiently protected against APAPinduced apoptosis via increasing Bcl-2/Bax ratio.CONCLUSION:CMN has significant therapeutic potential in both APAP-induced hepatotoxicity and other types of liver diseases.

Naringenin protects against isoniazid- and rifampicininduced apoptosis in hepatic injury

AIM To explore the protective effects and mechanisms of naringenin(NRG) on hepatic injury induced by isoniazid(INH) and rifampicin(RIF).METHODS Male mice were randomly divided into four groups and treated for 14 d as follows: normal control group was administered intragastrically with normal saline solution alone; model group was administered intragastrically with INH(100 mg/kg) and RIF(100 mg/kg); lowand high-dosage NRG pretreatment groups were administered intragastrically with different doses of NRG(50 or 100 mg/kg) 2 h before INH and RIF challenge. Mice were killed 16 h after the last dose of drug treatment to determine activity of serum transaminases. Oxidative stress was evaluated by measuring hepatic glutathione(GSH) and superoxide dismutase(SOD) and malondialdehyde(MDA) levels. Histopathological changes in hepatic tissue were observed under the optical microscope. Hepatocyte apoptosis was measured by TUNEL assay and caspase-3 activation. Expression of Bcl-2 and Bax in liver was determined by western blot.RESULTS Both low- and high-dosage NRG pretreatment obviously alleviated serum levels of alanine aminotransferase and aspartate aminotransferase, liver index, hepatic MDA content, and increased hepatic GSH content and SOD activity compared with the INH and RIF-treated group(44.71 ± 8.15 U/L, 38.22 ± 6.64 U/L vs 58.15 ± 10.54 U/L; 98.36 ± 14.78 U/L, 92.41 ± 13.59 U/L vs 133.05 ± 19.36 U/L; 5.34% ± 0.26%, 4.93% ± 0.25% vs 5.71% ± 0.28%; 2.76 ± 0.67 nmol/mgprot, 2.64 ± 0.64 nmol/mgprot vs 4.49 ± 1.12 nmol/mgprot; 5.91 ± 1.31 mg/gprot, 6.42 ± 1.42 mg/gprot vs 3.11 ± 0.73 mg/gprot; 137.31 ± 24.62 U/mgprot, 148.83 ± 26.75 U/mgprot vs 102.34 ± 19.22 U/mgprot; all P < 0.01 or 0.05). Histopathological evaluation showed obvious necrosis and inflammatory cell infiltration in liver of mice administered INH and RIF; however, mice pretreated with NRG showed minor hepatic injury. In addition, INH and RIF resulted in hepatocyte apoptosis, and NRG pretreatment dramatically suppressed INHand RIF-induced hepatocytes apoptosis. Furthermore, NRG-mediated anti-apoptotic effects seemed to be in connection with its regulation of Bax and Bcl-2 protein expression in hepatic tissue.CONCLUSION NRG might attenuate INH- and RIF-induced hepatic injury via suppression of oxidative stress and hepatocyte apoptosis.

Study on protecting effects of Baicalin and Octreotide on hepatic injury in rats with severe acute pancreatitis

AIM: To investigate the protective effects and mechanisms of Baicalin and Octreotide on hepatic injury in rats with severe acute pancreatitis (SAP). METHODS: The SAP rat models were prepared and randomly assigned to the model control group, Baicalin treated group, and Octreotide treated group while other healthy rats were assigned to the sham-operated group. Rat mortality, levels of ALT, AST, liver and pancreas pathological changes in all groups were observed at 3, 6 and 12 h after operation. Tissue microarray (TMA) sections of hepatic tissue were prepared to observe expression levels of Bax, Bcl-2 protein and Caspase-3, and changes of apoptotic indexes.RESULTS: Rat survival at 12 h, expression levels of Bax, Caspase-3 protein and apoptotic indexes of liver were all significantly higher in treated groups than in model control group. While the liver and pancreas pathological scores, contents of ALT, AST, and expression levels of Bcl-2 protein were all lower in treated groups than in the model control group. CONCLUSION: Both Baicalin and Octreotide can protect rats with SAP by decreasing the contents of ALT, AST and expression levels of Bcl-2 protein, and improving the expression levels of Bax protein, Caspase-3 protein, and inducing apoptosis.

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.

Study progress on mechanism of severe acute pancreatitis complicated with hepatic injury

Study on the action mechanism of inflammatory mediators generated by the severe acute pancreatitis （SAP） in multiple organ injury is a hotspot in the surgical field. In clinical practice, the main complicated organ dysfunctions are shock, respiratory failure, renal failure, encephalopathy, with the rate of hepatic diseases being closely next to them. The hepatic injury caused by SAP cannot only aggravate the state of pancreatitis, but also develop into hepatic failure and cause patient death, lts complicated pathogenic mechanism is an obstacle in clinical treatment. Among many pathogenic factors, the changes of vasoactive substances, participation of inflammatory mediators as well as OFR （oxygen free radical）, endotoxin, etc. may play important roles in its progression.

Two clinically relevant pressures of carbon dioxide pneumoperitoneum cause hepatic injury in a rabbit model

AIM:To observe the hepatic injury induced by carbon dioxide pneumoperitoneum(CDP) in rabbits,compare the eects olow-and high-pressure pneumoperitoneum,and to determine the degree o hepatic injury induced by these two clinically relevant CDP pressures.METHODS:Thirty healthy male New Zealand rabbits weighing 3.0 to 3.5 kg were randomly divided into three groups(n = 10 for each group) and subjected to the ollowing to CDP pressures:no gas control,10 mmHg,or 15 mmHg.Histological changes in liver tissues were observed with hematoxylin and eosin staining and transmission electron microscopy.Liver unction was evaluated using an automatic biochemical analyzer.Adenine nucleotide translocator(ANT) activity in liver tissue was detected with the atractyloside-inhibitor stop technique.Bax and Bcl-2 expression levels were detected bywestern blotting.RESULTS:Liver Functions in the 10 mmHg and 15 mmHg experimental groups were significantly disturbed compared with the control group.After CDP,the levels or alanine transaminase and aspartate transaminase were 77.3 ± 14.5 IU/L and 60.1 ± 11.4 IU/L,respectively,in the 10 mmHg experimental group and 165.1 ± 19.4 IU/L and 103.8 ± 12.3 IU/L,respectively,in the 15 mmHg experimental group,which were all higher than those of the control group(p < 0.05).There was no difference in pre-albumin concentration between the 10 mmHg experimental group and the control group,but the prealbumin level of the 15 mmHg experimental group was significantly lower than that of the control group(p < 0.05).No significant differences were observed in the levels of total bilirubin or albumin among the three groups.After 30 and 60 min of CDP,pH was reduced(p < 0.05) and fa CO2 was elevated(p < 0.05) in the 10 mmHg group compared with controls,and these changes were more pronounced in the 15 mmHg group.Hematoxylin and eosin staining showed no significant change in liver morphology,except for mild hyperemia in the two experimental groups.Transmission electron microscopy showed mild mitochondrial swelling in hepatocytes of the 10 mmHg group,and this was more pronounced in the 15 mmHg group.No significant difference in ANT levels was found between the control and 10 mmHg groups.However,ANT concentration was significantly lower in the 15 mmHg group compared with the control group.The expression of hepatic Bax was significantly increased in the two experimental groups compared with the controls,but there were no differences in Bcl-2 levels among the three groups.Twelve hours after CDP induction,the expression of hepatic Bax was more significant in the 15 mmHg group than in the 10 mmHg group.CONCLUSION:A CDP pressure of 15 mmHg caused more substantial hepatic injury,such as increased levels of acidosis,mitochondrial damage,and apoptosis;therefore,10 mmHg CDP is preferable for laparoscopic operations.

Hepatic injury induced by carbon dioxide pneumoperitoneum in experimental rats

AIM： To observe the hepatic injury induced by carbon dioxide pneumoperitoneum in rats and to explore its potential mechanism.METHODS： Thirty healthy male SD rats were randomly divided into control group （n = 10）, 0 h experimental group （n = 10） and 1 h experimental group （n = 10） after sham operation with carbon dioxide pneumoperitoneum. Histological changes in liver tissue were observed with hematoxylineosin staining. Liver function was assayed with an automatic biochemical analyzer. Concentration of malonyldialdehyde （MDA） and activity of superoxide dismutase （SOD） were assayed by colorimetry. Activity of adenine nucleotide translocator in liver tissue was detected with the atractyloside-inhibitor stop technique. Expression of hypoxia inducible factor-1 （HIF-1） mRNA in liver tissue was detected with in situ hybridization.RESULTS： Carbon dioxide 60 min could induce liver pneumoperitoneum for injury in rats. Alanine aminotransferase and aspartate aminotransferase were 95.7 ± 7.8 U/L and 86.8 ± 6.9 U/L in 0 h experimental group, and 101.4 ± 9.3 U/L and 106.6 ±8.7 U/L in 1 h experimental group. However, no significant difference was found in total billirubin, albumin, and pre-albumin in the three groups. In 0 h experimental group, the concentration of MDA was 9.83 ±2.53 μmol/g in liver homogenate and 7.64 ± 2.19 μmol/g in serum respectively, the activity of SOD was 67.58±9.75 nu/mg in liver and 64.47 ± 10.23 nu/mg in serum respectively. In 1 h experimental group, the concentration of MDA was 16.57±3.45 μmol/g in liver tissue and 12.49 ±4.21 μmol/g in serum respectively, the activity of SOD was 54.29 ±7.96 nu/mg in liver tissue and 56.31 ±9.85 nu/mg in serum respectively. The activity of ANT in liver tissue was 9.52 ± 1.56 in control group, 6.37± 1.33 in 0 h experimental group and 7.2 8±1.45 （10^-9 mol/min per gram protein） in 1 h experimental group, respectively. The expression of HIF-1 mRNA in liver tissue was not detected in control group, and its optical density difference value was 6.14±1.03 in 0 h experimental group and 9.51 ± 1.74 in 1 h experimental group, respectively. CONCLUSION： Carbon dioxide pneumoperitoneum during the sham operation can induce hepatic injury in rats. The probable mechanisms of liver injury include anoxia, ischemia reperfusion and oxidative stress. Liver injury should be avoided during clinical laparoscopic operation with carbon dioxide pneumoperitoneum.

Fisetin mitigates hepatic ischemia-reperfusion injury by regulating GSK3β/AMPK/NLRP3 inflammasome pathway

Background: Hepatic ischemia-reperfusion(I/R) injury(IRI) represents a crucial challenge in liver transplantation. Fisetin has anti-inflammatory, anti-aging and anti-oxidative properties. This study aimed to examine whether fisetin mitigates hepatic IRI and examine its underlying mechanisms. Methods: Sham or warm hepatic I/R operated mice were pretreated with fisetin(5, 10 or 20 mg/kg). Hepatic histological assessments, TUNEL assays and serum aminotransferase measurements were performed. An in vitro hypoxia/reoxygenation(H/R) model using RAW264.7 macrophages pretreated with fisetin(2.5, 5 or 10 μmol/L) was also used. Serum and cell supernatant concentrations of interleukin-1 β(IL-1 β), IL-18 and tumor necrosis factor-α(TNF-α) were determined by enzyme-linked immunosorbent assay(ELISA). Protein levels of p-GSK3 β, p-AMPK and NLR family pyrin domain-containing 3(NLRP3)-associated proteins were detected by Western blotting. Results: Compared with the I/R group, fisetin pretreatment reduced pathological liver damage, serum aminotransferase levels, serum concentrations of IL-1 β, IL-18 and TNF-α in the murine IRI model. Fisetin also reduced the expression of NLRP3 inflammasome-associated proteins(NLRP3, cleaved caspase-1, IL-1 β and IL-18) in I/R-operated liver. The experiments in vitro showed that fisetin decreased the release of IL-1 β, IL-18 and TNF-α, and reduced the expression of NLRP3 inflammasome-associated proteins in H/R-treated RAW264.7 cells. Moreover, fisetin increased the expressions of p-GSK3 β and p-AMPK in both models, indicating that its anti-inflammatory effects were dependent on GSK3 β/AMPK signaling. The antiinflammatory effects of fisetin were partially inhibited by the AMPK specific inhibitor compound C. Conclusions: Fisetin showed protective effects against hepatic IRI, countering inflammatory responses through mediating the GSK3 β/AMPK/NLRP3 inflammasome pathway.

Hepatic injury in rats with obstructive jaundice: roles of the protein kinase C signal pathway and cytoprotection of fructose

BACKGROUND: Fructose is cytoprotective during bile salt-induced apoptosis of hepatocytes by regulating protein kinase C (PKC). This study was undertaken to explore the regulating mechanism of hepatic injury in rats with obstructive jaundice, and to detect the PKC signal pathway. METHODS: Rat hepatocytes were isolated by in situ colla-genase perfusion and primary culture, and pretreated with various concentrations of PKC agonist phorbol myristate acetale (PMA) and inhibitor chelerythrine for 20 minutes. After pretreatment, 50 μmol/L glycochenodeoxycholate (GCDC) was added for additional 24 hours. Subsequently, the cells were detected by FCM and TUNEL. After adding with different concentrations of fructose and 100 μmol GCDC , the hepatocytes were evaluated by FCM and TUNEL. Experimental obstructive jaundice was induced with fructose and without fructose via double ligation of the bile duct for 3, 7, 14, and 21 days. Apoptotic status in the liver of all rats was detected with TUNEL, and PKC protein in the liver of obstructive jaundice ( OJ) with the immunohisto-chemistry method. RESULTS: PMA increased GCDC-induced apoptosis and chelerythrine decreased GCDC-induced apoptosis in a concentration-dependent manner. Adding with different concentration of fructose and 100 μmol GCDC, the decreased apoptotic rate was related to the concentration of fructose. The apoptotic rate of the liver was related to times of OJ. PKC and apoptosis index (AI) were the highest after a 14-day ligation of the bile duct without use of fructose. AI and PKC were decreasing from a 14-day ligation of the bile duct with fructose. CONCLUSIONS: PKC takes part in the regulation, occurrence , and progression of hepatic injury in OJ. Fructose is cytoprotective during bile salt-induced apoptosis of hepato-cytes by regulating PKC.

Early activated hepatic stellate cell-derived molecules reverse acute hepatic injury

AIM: To test whether hepatic stellate cells(HSCs) at different activation stages play different roles in acetaminophen(APAP)-induced acute liver injury(ALI).METHODS: HSCs were isolated from mouse liver and cultured in vitro.Morphological changes of initiation HSCs [HSCs(5d)] and perpetuation HSCs [HSCs(p3)] were observed by immunofluorescence and transmission electron microscopy.The protective effects of HSCderived molecules, cell lysates and HSC-conditioned medium(HSC-CM) were tested in vivo by survival and histopathological analyses.Liver injury was determined by measuring aminotransferase levels in the serum and by histologic examination of tissue sections under a light microscope.Additionally, to determine the molecular mediators of the observed protective effects of initiation HSCs, we examined HSC-CM using a highdensity protein array.RESULTS: HSCs(5d) and HSCs(p3) had different morphological and phenotypic traits.HSCs(5d) presented a star-shaped appearance with expressing α-SMA at non-uniform levels between cells.However, HSCs(p3) evolved into myofibroblast-like cells without lipid droplets and expressed a uniform and higher level of α-SMA.HSC-CM(5d), but not HSC-CM(p3), provided a significant survival benefit and showed a dramatic reduction of hepatocellular necrosis and panlobular leukocyte infiltrates in mice exposed to APAP.However, this protective effect was abrogated at higher cell masses, indicating a therapeutic window of effectiveness.Furthermore, the protein array screenrevealed that HSC-CM(5d) was composed of many chemokines and growth factors that correlated with inflammatory inhibition and therapeutic activity.When compared with HSC-CM(p3), higher levels of monocyte chemoattractant protein-1, macrophage inflammatory protein-1γ, hepatocyte growth factor, interleukin-10, and matrix metalloproteinase-2, but lower levels of stem cell factor and Fas-Ligand were observed in HSCCM(5d).CONCLUSION: These data indicated that initiation HSCs and perpetuation HSCs were different in morphology and protein expression, and provided the first experimental evidence of the potential medical value of initiation HSC-derived molecules in the treatment of ALI.

Role of adhesion molecules and dendritic cells in rat hepatic/renal ischemia-reperfusion injury and anti-adhesive intervention with anti-P-selectin lectin-EGF domain monoclonal antibody

AIM: To investigate the role of P-selectin, intercellular adhesion molecule-1 (ICAM-1) and dendritic cells (DCs)in liver/kidney of rats with hepatic/renal ischemiareperfusion injury and the preventive effect of anti-Pselectin lectin-EGF domain monoclonal antibody (anti-PsLEGFmAb) on the injury.METHODS: Rat models of hepatic and renal ischemiareperfusion were established. The rats were then divided into two groups, one group treated with anti-PsL-EGFmAb(n = 20) and control treated with saline (n = 20). Both groups were subdivided into four groups according to reperfusion time (1, 3, 6 and 24 h). The sham-operated group (n = 5) served as a control group. DCs were observed by the microscopic image method, while P-selectin and ICAM-1 were analyzed by immunohistochemistry.RESULTS: P-selectin increased significantly in hepatic sinusoidal endothelial cells and renal tubular epithelial cells 1 h after ischemia-reperfusion, and the expression of ICAM-1 was up-regulated in hepatic sinusoid and renal vessels after 6 h. CD1a+CD80+DCs gradually increased in hepatic sinusoidal endothelium and renal tubules and interstitium 1 h after ischemia-reperfusion, and there was the most number of DCs in 24-h group. The localization of DCs was associated with rat hepatic/renal function.These changes became less significant in rats treated with anti-PsL-EGFmAb.CONCLUSION: DCs play an important role in immune pathogenesis of hepatic/renal ischemia-reperfusion injury.Anti-PsL-EGFmAb may regulate and inhibit local DC immigration and accumulation in liver/kidney.