Inhibition of the cGAS–STING pathway:contributing to the treatment of cerebral ischemia-reperfusion injury

The cGAS–STING pathway plays an important role in ischemia-reperfusion injury in the heart,liver,brain,and kidney,but its role and mechanisms in cerebral ischemia-reperfusion injury have not been systematically reviewed.Here,we outline the components of the cGAS–STING pathway and then analyze its role in autophagy,ferroptosis,cellular pyroptosis,disequilibrium of calcium homeostasis,inflammatory responses,disruption of the blood–brain barrier,microglia transformation,and complement system activation following cerebral ischemia-reperfusion injury.We further analyze the value of cGAS–STING pathway inhibitors in the treatment of cerebral ischemia-reperfusion injury and conclude that the pathway can regulate cerebral ischemia-reperfusion injury through multiple mechanisms.Inhibition of the cGAS–STING pathway may be helpful in the treatment of cerebral ischemia-reperfusion injury.

HSP110 aggravates ischemia-reperfusion injury after liver transplantation by promoting NF-κB pathway

Background:Ischemia-reperfusion injury(IRI)poses a significant challenge to liver transplantation(LT).The underlying mechanism primarily involves overactivation of the immune system.Heat shock protein 110(HSP110)functions as a molecular chaperone that helps stabilize protein structures.Methods:An IRI model was established by performing LT on Sprague-Dawley rats,and HSP110 was silenced using siRNA.Hematoxylin-eosin staining,TUNEL,immunohistochemistry,ELISA and liver enzyme analysis were performed to assess IRI following LT.Western blotting and quantitative reverse transcription-polymerase chain reaction were conducted to investigate the pertinent molecular changes.Results:Our findings revealed a significant increase in the expression of HSP110 at both the mRNA and protein levels in the rat liver following LT(P<0.05).However,when rats were injected with siRNAHSP110,IRI subsequent to LT was notably reduced(P<0.05).Additionally,the levels of liver enzymes and inflammatory chemokines in rat serum were significantly reduced(P<0.05).Silencing HSP110 with siRNA resulted in a marked decrease in M1-type polarization of Kupffer cells in the liver and downregulated the NF-κB pathway in the liver(P<0.05).Conclusions:HSP110 in the liver promotes IRI after LT in rats by activating the NF-κB pathway and inducing M1-type polarization of Kupffer cells.Targeting HSP110 to prevent IRI after LT may represent a promising new approach for the treatment of LT-associated IRI.

Gut-liver axis in sepsis-associated liver injury:Epidemiology,challenges and clinical practice

Although the liver has a remarkable regenerative capacity,sepsis-associated liver injury(SLI)is a complication often seen in intensive care units.Due to its role in immune and inflammatory regulation,the liver is particularly vulnerable during severe infections.Understanding the global prevalence,causes,and management of SLI is essential to improve outcomes and reduce healthcare costs.This paper aims to explore these factors,with an emphasis on identifying effective strategies for clinical management.Zhang et al’s bibliometric analysis of 787 publications(745 original articles and 42 reviews,mostly in animal models)from 2000 to 2023 highlights the growing interest in SLI,focusing on oxidative stress,gut microbiota,and inflammatory processes.Key components such as nuclear factor-kappa B and the NOD-like receptor thermal protein domain associated protein 3 inflammasome pathway,along with their links to gut microbiota imbalance and oxidative stress,are crucial for understanding SLI pathogenesis.The gut-liver axis,particularly the role of intestinal permeability and bacterial translocation in liver inflammation,is emphasized.In this context,bacterial translocation is especially relevant for critically ill patients,as it can exacerbate liver inflammation.The findings underscore the need for integrated care in intensive care units,prioritizing gut health and careful antibiotic use to prevent dysbiosis.Despite extensive research,there remains a lack of clinical trials to validate therapeutic approaches.The abundance of experimental studies highlights potential therapeutic targets,stressing the need for high-quality randomized clinical trials to translate these findings into clinical practice.

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.

Gamma-aminobutyric acid enhances miR-21-5p loading into adipose-derived stem cell extracellular vesicles to alleviate myocardial ischemia-reperfusion injury via TXNIP regulation

BACKGROUND Myocardial ischemia-reperfusion injury(MIRI)poses a prevalent challenge in current reperfusion therapies,with an absence of efficacious interventions to address the underlying causes.AIM To investigate whether the extracellular vesicles(EVs)secreted by adipose mesenchymal stem cells(ADSCs)derived from subcutaneous inguinal adipose tissue(IAT)underγ-aminobutyric acid(GABA)induction(GABA-EVs^(IAT))demonstrate a more pronounced inhibitory effect on mitochondrial oxidative stress and elucidate the underlying mechanisms.METHODS We investigated the potential protective effects of EVs derived from mouse ADSCs pretreated with GABA.We assessed cardiomyocyte injury using terminal deoxynucleotidyl transferase dUTP nick end-labeling and Annexin V/propidium iodide assays.The integrity of cardiomyocyte mitochondria morphology was assessed using electron microscopy across various intervention backgrounds.To explore the functional RNA diversity between EVs^(IAT)and GABA-EVs^(IAT),we employed microRNA(miR)sequencing.Through a dual-luciferase reporter assay,we confirmed the molecular mechanism by which EVs mediate thioredoxin-interacting protein(TXNIP).Western blotting and immunofluorescence were conducted to determine how TXNIP is involved in mediation of oxidative stress and mitochondrial dysfunction.RESULTS Our study demonstrates that,under the influence of GABA,ADSCs exhibit an increased capacity to encapsulate a higher abundance of miR-21-5p within EVs.Consequently,this leads to a more pronounced inhibitory effect on mitochondrial oxidative stress compared to EVs from ADSCs without GABA intervention,ultimately resulting in myocardial protection.On a molecular mechanism level,EVs regulate the expression of TXNIP and mitigating excessive oxidative stress in mitochondria during MIRI process to rescue cardiomyocytes.CONCLUSION Administration of GABA leads to the specific loading of miR-21-5p into EVs by ADSCs,thereby regulating the expression of TXNIP.The EVs derived from ADSCs treated with GABA effectively ameliorates mitochondrial oxidative stress and mitigates cardiomyocytes damage in the pathological process of MIRI.

Network pharmacology investigation of the mechanism underlying the therapeutic action of Shikang granules in retinal ischemia-reperfusion injuries

Background:Retinal ischemia/reperfusion(I/R)injury often results in vision loss,and effective clinical management options are currently lacking.Shikang granules(SKG)are traditional Chinese medicine-based preparations commonly used in clinical practice for treating optic atrophy.Methods:Despite decades of clinical use,the precise mechanism of action(MoA)of SKG remains elusive.Here,we employ a network pharmacological approach to elucidate its MoA by identifying active ingredients and relevant targets using the Traditional Chinese Medicine System Pharmacology Database and Analytical Platform.Targets associated with retinal I/R injury were sourced from GeneCards,Online Mendelian Inheritance in Man,and DisGeNET.Venny software facilitated the identification of intersecting targets,which were then subjected to gene ontology functional analysis and Kyoto Encyclopedia of Genes and Genomes pathway analysis.To validate the protective effect and explore the MoA of SKG in retinal I/R injuries,we conducted experiments using rat models.Results:Our animal experiments demonstrated that SKG mitigated apoptosis following retinal I/R injury by upregulating the expression of the anti-apoptotic protein Bcl-2 and downregulating the expression of BAX,Caspase-9,Caspase-3,PARP,and cytochrome C.Additionally,SKG was found to increase the expression of PI3K and AKT.Conclusions:SKG may exert its protective effects by inhibiting apoptosis through modulation of pro-apoptotic and anti-apoptotic protein expression,as well as activation of the PI3K/AKT pathway.

Preliminary study on the protective effect of electroacupuncture Neiguan acupoint pretreatment on rats with myocardial ischemia-reperfusion injury:role of the miR-214-3p/NCX1 axis

Background:Ischemia-reperfusion can worsen myocardial damage and increase the risk of death.Studies have revealed that ischemic preconditioning provides the best endogenous protection against myocardial ischemia-reperfusion injury(MIRI),and the principle of electroacupuncture(EA)preconditioning is comparable to that of myocardial ischemic preconditioning adaption.Our earlier research demonstrated that EA pretreatment inhibits the expression of calmodulin-dependent protein kinase IIδ(CaMKIIδ),sodium/calcium exchanger 1(NCX1),and cyclophilin D,hence providing protection against MIRI.However,the exact mechanism is still unknown.The expression of NCX1 mRNA is directly regulated by microRNA-214(miR-214).Moreover,it suppresses the levels of CaMKIIδand cyclophilin D.Whether these variables contribute to EA preconditioning to improve MIRI needs to be investigated,though.This study aimed to preliminarily determine whether EA pretreatment ameliorates MIRI by modulating the miR-214-3p/NCX1 axis.Methods:We used a rat MIRI model to investigate the effect of EA pretreatment on MIRI and the expression of miR-214-3p.In addition,adenovirus injection inhibited miR-214-3p expression in the rat MIRI model,and the influence of EA pretreatment towards MIRI was observed in the context of blocked miR-214-3p expression.Both the myocardial histological abnormalities and the alterations in the ST segment of the rat electrocardiogram were analyzed.NCX1 mRNA,cyclophilin D,and CaMKIIδexpression levels were also analyzed.Results:EA pretreatment improved MIRI.In rats with MIRI,EA administration increased miR-214-3p expression while decreasing NCX1 mRNA,cyclophilin D,and CaMKIIδproteins in cardiac tissues.The beneficial effect of EA pretreatment against MIRI was reversed,coupled with elevated levels of NCX1 mRNA,cyclophilin D,and CaMKIIδprotein expression,when an adenovirus injection disrupted the expression of miR-214-3p.Conclusions:Our findings preliminarily show that EA pretreatment inhibits the expression of NCX1 mRNA,cyclophilin D,and CaMKIIδproteins via miR-214-3p,hence exerting MIRI protection.

The mechanisms that regulate neuronal pyroptosis in cerebral ischemia-reperfusion injury:current theories and recent advances

Early or ultra-early pharmacological thrombolysis together with mechanical thrombectomy are key treatments for ischemic stroke,and both are aimed at vascular recanalization and improved collateral circulation.While these methods enhance tissue perfusion in the ischemic penumbra,they also trigger complex neurotoxic reactions,including apoptosis,acidosis,ion imbalance,oxidative stress,and pyroptosis,exacerbating cerebral ischemia-reperfusion injury(CIRI).Pyroptosis,a recently discovered form of programmed cell death driven by inflammation,plays a significant role in neuronal death during CIRI.This study reviews the regulatory mechanisms of pyroptosis in CIRI.

Hepatic ischemia-reperfusion injury in liver transplant setting:mechanisms and protective strategies

Hepatic ischemia-reperfusion injury is a major cause of liver transplant failure,and is of increasing significance due to increased use of expanded criteria livers for transplantation.This review summarizes the mechanisms and protective strategies for hepatic ischemia-reperfusion injury in the context of liver transplantation.Pharmacological therapies,the use of pre-and post-conditioning and machine perfusion are discussed as protective strategies.The use of machine perfusion offers significant potential in the reconditioning of liver grafts and the prevention of hepatic ischemia-reperfusion injury,and is an exciting and active area of research,which needs more study clinically.

Protective effects of L-arginine against ischemia-reperfusion injury in non-heart beating rat liver graft

BACKGROUND: Although the use of non-heart beating donors (NHBDs) could bridge the widening gap between organ demand and supply, its application to liver transplantation is limited due to the high incidence of primary graft loss. Prevention of liver injury in NHBDs will benefit the results of transplantation. This study was conducted to evaluate the protective effects of L-arginine on liver grafts from NHBDs. METHODS: One hundred and four Wistar rats were randomly divided into 7 groups: normal control (n=8) controls 1, 2 and 3 (C-1, C-2, C-3, n=16), and experimental 1, 2 and 3 (E-1, E-2, E-3, n=16). For groups C-1 and E-1, C-2 and E-2, and C-3 and E-3, the warm ischemia time was 0, 30, and 45 minutes, respectively. Liver grafts were flushed with and preserved in 4 degrees C Euro-collins solution containing 1 mmol/L L-arginine for 1 hour in each experimental group. Recipients of each experimental group were injected with L-arginine (10 mg/kg body weight) by tail vein 10 minutes before portal vein reperfusion. Donors and recipients of each experimental control group were treated with normal saline. Then transplantation was performed. At 1, 3, and 24 hours after portal vein reperfusion, blood samples were obtained to determine the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), nitric oxide (NO) and plasma endothelin (ET). At 3 hours after portal vein reperfusion, grafts samples were fixed in 2.5% glutaraldehyde for electron microscopic observation. RESULTS: At I hour after portal vein reperfusion, the levels of NO in groups E-1, E-2, E-3 and C-1, C-2, C-3 were lower, while the levels of plasma ET, serum ALT and AST were higher than those in the normal control group (P<0.05). At 1, 3, and 24 hours, the levels of NO in groups E-1, E-2, E-3 were higher, while the levels of plasma ET, serum ALT and AST were lower than those in the corresponding control groups (C-1, C-2, C-3) (P<0.05). The levels of NO in groups C-2 and C-3 were lower than in group C-1 (P<0.05), and the level of NO in group C-3 was lower than in group C-2 (P<0.05). At 1, 3 and 24 hours, the levels of plasma ET, serum ALT, and AST in groups E-1, E-2, E-3 were lower than those in the corresponding control groups (C-1, C-2, C-3) (P<0.05). The levels of plasma ET, serum ALT, and AST were lower in group C-3 than in groups C-1 and C-2 (P<0.05). Pathological changes in groups E-1, E-2, E-3 were milder than those in the corresponding experimental control groups (C-1, C-2, C-3). CONCLUSIONS: The imbalance between NO and ET plays an important role in the development of ischemia-reperfusion injury of liver grafts from NHBDs. L-arginine can attenuate injury in liver grafts from NHBDs by improving the balance between NO and ET.

N-acetylcysteine inhibits activation of toll-like receptor 2 and 4 gene expression in the liver and lung after partial hepatic ischemia-reperfusion injury in mice

BACKGROUND: Toll-like receptor 2 and 4 (TLR2/4) may play important roles in ischemia-reperfusion (I/R) injury, and N-acetylcysteine (NAC) can prevent the generation of reactive oxygen species (ROS) induced by I/R injury. This study aimed to investigate the changes in TLR2/4 gene expression in the liver and lung after I/R injury with or without NAC pretreatment. METHODS: BALB/c mice were used in a model of partial hepatic I/R injury and randomly assigned to a sham-operated control group (SH), a hepatic ischemia/reperfusion group (I/R) or a NAC pretreated, hepatic I/R group (I/R-NAC). The levels of TNF-alpha in the portal vein and plasma alanine aminotransferase (ALT) were measured at 1 and 3 hours after reperfusion. The lung wet-to-dry ratio was measured, and the expression of TLR2/4 mRNA and protein in the liver and lung were assessed with RT-PCR and Western blotting at the same time points. RESULTS: Compared with the I/R group, the expression of TLR2/4 mRNA and protein in the liver and lung in the I/R-NAC group was decreased at the same time point (P<0.05). The levels of portal vein TNF-a and plasma ALT increased continuously in the l/R group at I and 3 hours of reperfusion compared with the SH group; however, they declined significantly in the group pretreated with NAC (P<0.05). The extent of lung edema was relieved in the I/R-NAC group compared with the I/R group (P<0.05). CONCLUSIONS: TLR2/4 was activated in the liver and lung in the process of partial hepatic I/R injury. NAC inhibited the activation of TLR2/4 and the induction of TNF-alpha resulting from I/R injury via modulating the redox state, thus it may mitigate liver and lung injury following partial hepatic I/R in mice.

N-acetylcysteine attenuates reactive-oxygen-speciesmediated endoplasmic reticulum stress during liver ischemia-reperfusion injury

AIM: To investigate the effects of N-acetylcysteine (NAC) on endoplasmic reticulum (ER) stress and tissue injury during liver ischemia reperfusion injury (IRI).

Protective effect of pyrrolidine dithiocarbamate on liver injury induced by intestinal ischemia-reperfusion in rats

BACKGROUND: The nuclear translocation of transcription factors may be a critical factor in the intracellular pathway involved in ischemia/reperfusion(I/R) injury. The aim of the study was to evaluate the role of nuclear factor-kappa B (NF-κB) in the pathogenesis of liver injury induced by intestinal ischemia/reperfusion (IIR) and to investigate the effect of pyrrolidine dithiocarbamate (PDTC) on this liver injury. METHODS: Male Wistar rats were divided randomly into three experimental groups (8 rats in each): sham operation group (control group); intestinal/reperfusion group(I/R group): animals received 1-hour of intestinal ischemia and 2-hour reperfusion; and PDTC treatment group (PDTC group): animals that received I/R subject to PDTC treatment (100 mg/kg). The histological changes in the liver and intestine were observed, and the serum levels of tumor necrosis factor-α (TNF-α), alanine aminotransferase (ALT), aspartate aminotransferase (AST), liver superoxide dismutase (SOD), and nitrite/nitrate (NO) were measured. The immunohistochemical expression and Western blot analysis of liver NF-κB and intercellular adhesion molecule-1(ICAM-1) were observed. RESULTS: IIR induced liver injury characterized by the histological changes of liver edema, hemorrhage, polymorphonuclear neutrophil (PMN) infiltration, and elevated serum levels of AST and ALT. The serum TNF-α level was significantly higher than that of the control group(P<0.01) and a high level of liver oxidant product was observed (P<0.01). These changes were parallel to the positive expression of NF-κB and ICAM-1. After the administration of PDTC, the histological changes after liver injury were improved; the levels of SOD and NO in the liver were elevated and reduced, respectively (P<0.01). The expressions of ICAM-1 and NF-κB in the liver were weakened (P<0.01). CONCLUSION: NF-κB plays an important role in the pathogenesis of liver injury induced by HR. PDTC, an agent known to inhibit the activation of NF-κB, can reduce and prevent this injury.

Influence of Kupffer cells and platelets on ischemia-reperfusion injury in mild steatotic liver

AIM: To investigate the effect of mild steatotic liver on ischemia-reperfusion injury by focusing on Kupffer cells (KCs) and platelets. METHODS: Wistar rats were divided into a normal liver group (N group) and a mild steatotic liver group (S group) induced by feeding a choline-deficient diet for 2 wk. Both groups were subjected to 20 min of warm ischemia followed by 120 min of reperfusion. The number of labeled KCs and platelets in sinusoids and the blood perfusion in sinusoids were observed by intravital microscopy (IVM), which was performed at 30, 60 and 120 min after reperfusion. To evaluate serum alanine aminotransferase as a marker of liver deterioration, blood samples were taken at the same time as IVM.RESULTS: In the S group, the number of platelets adhering to KCs decreased significantly compared with the N group (120 after reperfusion; 2.9±1.1 cells/acinus vs 4.8±1.2 cells/acinus, P<0.01). The number of KCs in sinusoids was significantly less in the S group than in the N group throughout the observation periods (before ischemia, 19.6±3.3 cells/acinus vs 28.2±4.1 cells/acinus, P<0.01 and 120 min after reperfusion, 29.0±4.3 cells/acinus vs 40.2±3.3 cells/acinus, P<0.01). The blood perfusion of sinusoids 120 min after reperfusion was maintained in the S group more than in the N group. Furthermore, elevation of serum alanine aminotransferase was lower in the S group than in the N group 120 min after reperfusion (99.7±19.8 IU/L vs 166.3±61.1 IU/L, P=0.041), and histological impairment of hepatocyte structure was prevented in the S group. CONCLUSION: Ischemia-reperfusion injury in mild steatotic liver was attenuated compared with normal liver due to the decreased number of KCs and the reduction of the KC-platelet interaction.

Recombinant adenovirus vector Ad-hIL-10 protects grafts from cold ischemia-reperfusion injury following orthotopic liver transplantation in rats

BACKGROUND: Interleukin 10 (IL-10), a Th2 type cytokine, modulates inflammatory responses by inhibiting the production of proinflammatory cytokines. This study was designed to investigate the protective effects of adenovirus-mediated human IL-10 (Ad-hIL-10) gene transfer on protecting grafts from cold ischemia-reperfusion injury following orthotopic liver transplantation in rats. METHODS: Adenoviruses encoding hIL-10 or beta-galactosidase (Ad-lacZ) were injected via the superior mesenteric vein into prospective donor animals. The donor liver was harvested 48 hours after transduction, and stored for 12 hours at 4 degrees C in lactated Ringer's solution prior to transplantation. The rats were divided into saline, Ad-lacZ, and Ad-hIL-10 groups. Liver function test, histopathological examination, reverse transcriptase-polymerase chain reaction (RT-PCR), and Western blotting were performed at 24 hours after transplantation in the three groups. RESULTS: Liver function (ALT and AST) was significantly improved, and the Suzuki score was significantly decreased in the Ad-hIL-10 group. The levels of hepatic TNF-alpha, MIP-2, ICAM-1 mRNA, and NF-kappa B protein in the Ad-hIL-10 group were significantly decreased. The expression of hIL-10 mRNA was detected by RT-PCR in Ad-hIL-10-treated grafts but not in controls treated with saline or Ad-lacZ. CONCLUSIONS: Donor pretreatment with Ad-hIL-10 down-regulates the expression of proinflammatory cytokines TNF-alpha, MIP-2, and ICAM-1 mRNA. hIL-10 protects against hepatic cold ischemia-reperfusion injury, at least in part, by suppressing NF-kappa B activation and subsequent expression of proinflammatory mediators. (Hepatobiliary Pancreat Dis Int 2010; 9: 144-148)

Neutrophil-mediated liver injury during hepatic ischemia-reperfusion in rats

BACKGROUND: Neutrophil plays an important role in hepatic ischemia-reperfusion injury. We investigated neutrophil infiltration in liver tissue, Kupffer cells' role in neutrophil accumulation, and apoptosis and regeneration of hepatocytes in liver ischemia-reperfusion injury. METHODS: Vascular microclamps were placed across the pedicles of the median and left lateral lobes for 90 minutes after 30% hepatectomy with the resection of caudate, right lateral and quadrate lobes and papillary process. Gadolinium chloride (GdCl3) was used to destroy Kupffer cells. Neutrophil activity was inhibited with Urge-8, a monoclonal antibody against neutrophil produced in our laboratory. GdCl3 (10 mg/kg) and Urge-8 (50 mg/kg) were given intravenously in respective groups. Ischemia control, GdCl3 and Urge-8 groups were compared. RESULTS: Following hepatic reperfusion, serum interleukin-8 (IL-8) levels and hepatic neutrophil counts peaked at 3 hours, and peak concentrations of alanine aminotransferase (ALT) occurred at 6 hours. Animals of the control group showed increases in neutrophil infiltration in liver tissue, liver enzyme levels, and apoptosis index of hepatocytes and decreases in overall survival rate and proliferating cell nuclear antigen (PCNA) expression of hepatocytes. The survival rates and PCNA proportion of hepatocytes were higher and the levels of hepatic neutrophil infiltration, liver enzymes, and hepatocyte apoptosis after reperfusion were lower in the GdCl3 and Urge-8 groups than those in the ischemia control group. CONCLUSIONS: Blockades of Kupffer cells' activity and neutrophil infiltration by GdCl3 and Urge-8 eliminate neutrophil-mediated hepatic injury and enhance subsequent hepatic regeneration during liver ischemiareperfusion.

Failure of P-selectin blockade alone to protect the liver from ischemia-reperfusion injury in the isolated blood-perfused rat liver

AIM： To determine if blockade of P-selectin in the isolated blood-perfused cold ex vivo rat liver model protects the liver from ischemia-reperfusion injury. METHODS： The effect of P-selectin blockade was assessed by employing an isolated blood-perfused cold ex vivo rat liver with or without P-selectin antibody treatment before and after 6 h of cold storage in University of Wisconsin solution. RESULTS： In our isolated blood-perfused rat liver model, pre-treatment with P-selectin antibody failed to protect the liver from ischemia-reperfusion injury, as judged by the elevated aspartate aminotransferase activity. In addition, P-selectin antibody treatment did not significantly reduced hepatic polymorphonuclear leukocyte accumulation after 120 min of perfusion. Histological evaluation of liver sections obtained at 120 min of perfusion showed significant oncotic necrosis in liver sections of both ischemic control and P-selectin antibody-treated groups. However, total bile production after 120 rain of perfusion was significantly greater in P-selectin antibody-treated livers, compared to control livers. No significant difference in P-selectin and ICAM-1 mRNAs and proteins, GSH, GSSG, and nuclear NF-kB was found between control and P-selectin antibody-treated livers. CONCLUSION： In conclusion, we have shown that blockade of P-selectin alone failed to reduced polymorphonuclear leukocyte accumulation in the liver and protect hepatocytes from ischemia-reperfusion injury in the isolated blood-perfused cold-ex vivo rat liver model.

Remote ischemic preconditioning protects liver ischemia-reperfusion injury by regulating eNOS-NO pathway and liver microRNA expressions in fatty liver rats

BACKGROUND: Ischemic preconditioning (IPC) is a strategy to reduce ischemia-reperfusion (I/R) injury. The protective effect of remote ischemic preconditioning (RIPC) on liver I/R injury is not clear. This study aimed to investigate the roles of RIPC in liver I/R in fatty liver rats and the involvement of endothelial nitric oxide synthase-nitric oxide (eNOS-NO) pathway and microRNA expressions in this process. METHODS: A total of 32 fatty rats were randomly divided into the sham group, I/R group, RIPC group and RIPC+I/R group. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and nitric oxide (NO) were measured. Hematoxylin-eosin staining was used to observe histological changes of liver tissues, TUNEL to detect hepatocyte apoptosis, and immunohistochemistry assay to detect heat shock protein 70 (HSP70) expression. Western blotting was used to detect liver inducible NOS (iNOS) and eNOS protein levels and realtime quantitative polymerase chain reaction to detect miR-34a, miR-122 and miR-27b expressions. RESULTS: Compared with the sham and RIPC groups, serum ALT, AST and iNOS in liver tissue were significantly higher in other two groups, while serum NO and eNOS in liver tissue were lower, and varying degrees of edema, degeneration and inflammatory cell infiltration were found. Cell apoptosis number was slightly lower in the RIPC+I/R group than that in I/R group. Compared with the sham group, HSP70 expressions were significantly increased in other three groups (all P<0.05). Compared with the sham and RIPC groups, elevated miR-34a expressions were found in I/R and RIPC+I/R groups (P<0.05). MiR-122 and miR-27b were found significantly decreased in I/R and RIPC+I/R groups compared with the sham and RIPC groups (all P<0.05). CONCLUSION: RIPC can reduce fatty liver I/R injury by affecting the eNOS-NO pathway and liver microRNA expressions.

Effect of Shenfu injection on ischemia-reperfusion injury of rat liver graft

BACKGROUND: It is reported that Shenfu injection (an injection prepared from traditional Chinese medicines red ginseng and aconite root) can decrease the extent of ischemia-reperfusion injury to many organs, such as the heart and kidney. We therefore investigated the effect of Shenfu injection on ischemia-reperfusion injury of rat liver graft and its mechanism. METHODS: Male Sprague Dawley (SD) rats were used as a model for isogeneic orthotopic liver transplantation. Sixty rats were randomly devided into two groups (30 in each group). The recipient was given intravenous Shenfu injection immediately before the removal of the liver in the Shenfu group and normal saline of the same volume in the control group. At 3, 6 and 24 hours after the reperfusion, blood and hepatic tissue were taken for examination. RESULTS: The levels of superoxide dismutase (SOD) and nitric oxide (NO) increased more significantly in the Shenfu group than in the control group (P <0.05). The levels of serum liver enzymes, hyaluronic acid (HA), malondialde-hyde (MDA), tumor necrosis factor-alpha(TNF-α), inter-leukin-1 (IL-1), endothelin -1 (ET-1) and liver cell apopto-sis index were lower in the Shenfu group than in the control group (P <0. 05). Microscopic examination revealed that the morphological changes of hepatic tissue were more severe in the control group than in the Shenfu group. CONCLUSIONS: Shenfu injection has protective effect on ischemia-reperfusion injury of rat liver graft. It inhibits the production of oxygen free radical and the activation of Kupffer cells, decreases apoptosis of liver cell, and improves microcirculation.

Effect of ONO-4057 and tacrolimus on ischemia-reperfusion injury of the liver

AIM: To investigate the effects of a novel Leukotriene B4 receptor antagonist and/or tacrolimus on ischemia-reperfusion in a rat liver model. METHODS: Male Lewis rats were pretreated with ONO-4057 (100 mg/kg) and/or tacrolimus (1 mg/kg) orally, and divided into four experimental groups; group 1 (control), group 2 (ONO-4057), group 3 (tacrolimus), group 4 (ONO-4057 + tacrolimus). RESULTS: There was a tendency for long survival in the groups treated with tacrolimus alone and ONO-4057 plus tacrolimus. Post-reperfusion serum aspartate aminotransferase levels decreased more signif icantly in ONO-4057 plus tacrolimus group (P < 0.01), than in the tacrolimus alone group (P < 0.05), compared to controls. CONCLUSION: This study demonstrated that pretreat-ment with ONO-4057 in combination with tacrolimus produced additive effects in a rat model of liver isch-emia-reperfusion injury.