Hepatic ischemia and reperfusion injury: effects on the liver sinusoidal milieu

A biomimetic nanomedicine alleviates liver transplant-related biliary injury by sequentially inhibiting oxidative stress and regulating macrophage polarization via Nrf-2/HO-1 and JNK pathways

Liver transplantation is an effective method for treating end-stage liver disease. However, 10-20 % of liver transplantation patients develop biliary injury, the main cause of which is ischemia-reperfusion injury (IRI), which consists of oxidative stress injury in the early stage and inflammatory injury in the advanced stage. Biliary injury seriously affects patient outcomes and even leads to mortality, and there are few effective treatments for IRI. Herein, nanoparticles containing quercetin (QR) and rapamycin (RP) coated with poly (lactic-co-glycolic acid) (PLGA) and encapsulated by platelet membrane (PM) were designed to treat IRI in the liver transplantation. The specific binding of ICAM-1 expressed on the PM to integrins (e.g., LFA-1 and Mac-1) in damaged vascular endothelial cells, as well as the interaction between P-selectin on the platelet surface and PSGL-1 on the macrophage surface, allows the accumulation of these biomimetic cell membrane-encapsulated nanoparticles, and subsequently, the delivery of both drugs, to ischemia-reperfusion sites in the liver. The encapsulated QR alleviated oxidative stress injury by activating the Nrf-2/HO-1 signaling pathway in the early stage in model rats with IRI and liver transplantation models. Moreover, RP alleviated inflammatory damage in the advanced stage by suppressing the JNK signaling pathway in M1 macrophages. Thus, these biomimetic nanoparticles that intervene in IRI to alleviate both the early oxidative stress and the advanced inflammatory response constitute a novel delivery system for managing biliary injury after liver transplantation.

Dexmedetomidine Cannot Attenuate Liver Injury and Improve Outcomes Following Laparoscopic Living Donor Hepatectomy: A Randomised Controlled Trial

Purpose

To determine the effects of intraoperative dexmedetomidine (DEX) administration on postoperative ischaemia/reperfusion injury (HIRI) and clinical outcomes of patients undergoing the laparoscopic living donor hepatectomy (LLDH).

Patients and Methods

Fifty-five patients who underwent the LLDH were randomly assigned to the DEX or control group. The DEX group received an intravenous infusion of DEX with an bolus dose of 1 µg/kg for 15 min before anaesthesia induction, followed by a continuous infusion at a rate of 0.4 µg/kg/h until the portal branch was disconnected. The control group was given an intravenous infusion of 0.9% saline at same volume and rate. The primary outcome was peak serum aspartate aminotransferase (AST) level during the first 72 h postoperatively. The secondary outcomes included other variables of postoperative liver and kidney function, intraoperative hemodynamic changes, postoperative recovery outcomes and the occurrence of complications.

Results

The peak serum AST level during the first 72 h postoperatively was not significantly different between groups (DEX vs control: 288 [194-466] vs 324 [194-437] IU/L; difference, -1.2 IU/L; 95% CI, -86.9 to 88.0; P=0.973). The intraoperative mean artery pressure was not significantly different, but intraoperative heart rate was significantly decreased in the DEX group. There were no significant differences between groups in other secondary outcomes.

Conclusion

This study demonstrates that intraoperative DEX administration at the studied dosage regimens cannot attenuate postoperative HIRI and does not improve clinical outcomes in patients undergoing the LLDH.

Clinical Trial Registration

www.chictr.org.cn, ChiCTR2000040629.

SLP65/SLP76 Csk-interacting membrane protein promotes hepatic ischemia-reperfusion injury by activating TLR4/Erk1/2-mediated macrophages M1 polarization

BACKGROUND

SLP65/SLP76, Csk-interacting membrane protein (SCIMP), is a membrane protein plays a crucial role in the regulation of macrophage polarization. This study aimed to investigate the mechanism of SCIMP-mediated M1 polarization in liver macrophages and ischemia-reperfusion injury (IRI) in liver transplantation.

METHODS

Mice underwent orthotopic liver transplantation. In in vivo experiments, mice were divided into the Sham group, LT group, LT+Scramble group, LT+SCIMP (-) group, and LT+ERK1/2 (-) group, and SCIMP or ERK1/2 knockdown was performed using AAV-Erk1/2-RNAi-F4/80-EGFP and AAV-SCIMP-RNAi-F4/80-EGFP. In the subsequent in vitro experiments with primary cells, macrophages were divided into the Ctrl group, H/R group, H/R+Scramble group, H/R+SCIMP (-) group, and H/R+ERK1/2 (-) group, with SCIMP knockdown achieved using siRNA. Immunoprecipitation (IP) was used to detect the interaction between TLR4 and Erk1/2. Liver damage was detected by Hematoxylin and eosin (HE) staining. Polarization was detected by western blot (WB), RT-PCR, immunohistochemistry (IHC), immunofluorescence technique (IF), enzyme-linked immunosorbent assay (ELISA) and flow cytometry (FC).

RESULTS

Knockdown of SCIMP ameliorated hepatic IRI and liver macrophages M1 polarization. Mechanically, SCIMP promoted the interaction between Erk1/2 and TLR4 in hypoxia/reoxygenation (H/R)-induced liver macrophages, while the inhibition of Erk1/2 reduced liver macrophages M1 polarization and liver IRI.

CONCLUSION

SCIMP promotes hepatic ischemia-reperfusion injury by activating TLR4/Erk1/2-mediated liver macrophages M1 polarization, which might become a potential therapeutic target in clinic.

G-LERP/miR-374i-b Attenuates IRI and Suppresses Hepatocellular Carcinoma Progression

BACKGROUND

Liver transplantation (LT) is the most effective therapeutic strategy for late-stage hepatocellular carcinoma (HCC), but it is prone to ischemia-reperfusion injury (IRI), leading to poor prognosis. Previous articles have reported that miR-374b-5p expression is increased in HCC tissues, and its relationship with IRI and HCC carcinoma progression is unclear.

METHODS

Previous reports have shown that miR-374b-5p expression is significantly upregulated in HCC tissues. The effect of miR-374b-5p on patient symptoms and prognosis were analyzed from The Cancer Genome Atlas database and liver specimens from LT patients. To further explore its therapeutic potential, a liver-targeted esterase-responsive gene delivery system (G-LERP/miR-374i-b) was developed to downregulate miR-374b-5p expression in the mouse hepatic IRI (HIRI) model. An orthotopic HCC model was further established to mimic the postoperative recurrence of HCC.

RESULTS

In this study, we found that miR-374b-5p expression correlates with tumor size and microvascular invasion based on patients' clinical information. Patients with low miR-374b-5p expression had a higher Milan criteria score and a lower Model for End-stage Liver Disease score. We verified the positive correlation between miR-374b-5p expression and the proliferation and invasion of HCC cells. Effective downregulation of miR-374b-5p simultaneously alleviated HIRI and reduced tumor burden by 56%, whereas miR-374b-5p upregulation promoted HCC progression. Furthermore, we found G-LERP/miR-374i-b attenuated hepatic inflammation by downregulating the nuclear factor kappa-B pathway, thereby reducing HIRI and the risk of HCC recurrence.

CONCLUSIONS

This research is the first to demonstrate miR-374b-5p as a dual therapeutic target during LT and postoperative recurrence of HCC. Preintervention of miR-374b-5p using an esterase-responsive gene delivery system during the preoperative period simultaneously alleviates IRI and suppresses HCC progression.

Mechanism of Reactive Oxygen/Nitrogen Species in Liver Ischemia-Reperfusion Injury and Preventive Effect of Chinese Medicine

Liver ischemia-reperfusion injury (LIRI) is a pathological process involving multiple injury factors and cell types, with different stages. Currently, protective drugs targeting a single condition are limited in efficacy, and interventions on immune cells will also be accompanied by a series of side effects. In the current bottleneck research stage, the multi-target and obvious clinical efficacy of Chinese medicine (CM) is expected to become a breakthrough point in the research and development of new drugs. In this review, we summarize the roles of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in various stages of hepatic ischemia-reperfusion and on various types of cells. Combined with the current research progress in reducing ROS/RNS with CM, new therapies and mechanisms for the treatment of hepatic ischemia-reperfusion are discussed.

Remimazolam alleviates hepatic ischemia-reperfusion injury by activating FOXO1/3 signaling : Remimazolam alleviates hepatic ischemia reperfusion injury

BACKGROUND

Hepatic ischemia reperfusion injury (HIRI) frequently gives rise to aggravated liver damage. Currently, there exists a diverse range of anesthetic drugs that possess protective capabilities against ischemia-reperfusion injury (IRI). Nevertheless, the specific functions and underlying mechanisms of remimazolam (RMZL) in HIRI have not been fully elucidated.

METHODS

HIRI models of both hepatocytes and mice were successfully established. To evaluate liver function and injury, ELISA, HE and TUNEL staining were employed. The levels of oxidative stress markers and inflammatory factors were measured using commercial kits. Cell viability and apoptosis were measured by CCK-8 and flow cytometry, respectively. The abundance of genes and proteins was determined utilizing RT-qPCR and western blot.

RESULTS

It was observed that RMZL administration greatly alleviated liver damage and repressed oxidative stress and inflammation in HIRI mouse models. In vitro experiments demonstrated that RMZL strongly protected LO2 cells from H/R-induced cell damage, oxidative stress, and inflammatory responses. Moreover, FOXO1 and FOXO3, which function as classic cell protection and anti-oxidative stress factors, were observed to be downregulated in liver tissue from HIRI mouse models and H/R-challenged LO2 cells. Notably, this downregulation could be reversed by the administration of RMZL. Furthermore, FOXO1 or FOXO3 knockdown abolished the protective effects of RMZL, including promoted cell survival and inhibited oxidative stress and inflammation in LO2 cells upon H/R exposure.

CONCLUSION

These data provided robust support for the notion that RMZL attenuated oxidative stress and inflammation to alleviate HIRI through enhancing FOXO1 and FOXO3 expressions, suggesting that RMZL holds great promise as a potential candidate anesthetic for HIRI treatment.

Protein modifications in hepatic ischemia-reperfusion injury: molecular mechanisms and targeted therapy

Ischemia-reperfusion injury refers to the damage that occurs when blood supply is restored to organs or tissues after a period of ischemia. This phenomenon is commonly observed in clinical contexts such as organ transplantation and cardiac arrest resuscitation. Among these, hepatic ischemia-reperfusion injury is a prevalent complication in liver transplantation, significantly impacting the functional recovery of the transplanted liver and potentially leading to primary graft dysfunction. With the growing demand for organ transplants and the limited availability of donor organs, effectively addressing hepatic ischemia-reperfusion injury is essential for enhancing transplantation success rates, minimizing complications, and improving graft survival. The pathogenesis of hepatic ischemia-reperfusion injury is multifaceted, involving factors such as oxidative stress and inflammatory responses. This article focuses on the role of protein post-translational modifications in hepatic ischemia-reperfusion injury, including phosphorylation, ubiquitination, acetylation, ADP-ribosylation, SUMOylation, crotonylation, palmitoylation, and S-nitrosylation. Initially, we examined the historical discovery of these protein post-translational modifications and subsequently investigated their impact on cellular signal transduction, enzymatic activity, protein stability, and protein-protein interactions. The emphasis of this study is on the pivotal role of protein post-translational modifications in the progression of hepatic ischemia-reperfusion injury and their potential as therapeutic targets. This study aims to conduct a comprehensive analysis of recent advancements in research on protein modifications in hepatic ischemia-reperfusion injury, investigate the underlying molecular mechanisms, and explore future research trajectories. Additionally, future research directions are proposed, including the exploration of interactions between various protein modifications, the identification of specific modification sites, and the development of drugs targeting these modifications. These efforts aim to deepen our understanding of protein post-translational modifications in hepatic ischemia-reperfusion injury and pave the way for innovative therapeutic interventions.

MAFF alleviates hepatic ischemia-reperfusion injury by regulating the CLCF1/STAT3 signaling pathway

BACKGROUND

Although hepatic ischemia-reperfusion injury (IRI) frequently occurs during liver resection and transplantation, the underlying mechanisms remain incompletely understood. Through high-throughput sequencing, we found that v-maf musculoaponeurotic fibrosarcoma oncogene homolog F (MAFF) expression was significantly increased after hepatic IRI. The specific role of MAFF, a basic leucine zipper (bZIP) transcription factor, in hepatic IRI is unknown. In the present study, we aimed to explore the effect of MAFF on hepatic IRI injury.

APPROACH AND RESULTS

Adenovirus vectors carrying the MAFF gene were administered to mice to explore the potential significance of MAFF. After ischemia-reperfusion, MAFF expression was significantly upregulated, suggesting a potential association between MAFF expression and hepatocyte apoptosis. A reduction in MAFF expression was demonstrated to worsen hepatic impairment and enhance the expression of proinflammatory cytokines in mice following ischemia-reperfusion. Conversely, MAFF overexpression had the opposite effect. Mechanistically, the combination of CUT&Tag and RNA sequencing technologies identified cardiotrophic factor-like cytokine 1 (CLCF1) as a direct transcriptional target for MAFF and BTB and CNC homology 1 (BACH1) heterodimers. This interaction subsequently triggers signal transducer and activator of transcription 3 (STAT3) signaling.

CONCLUSIONS

MAFF alleviates hepatic ischemia-reperfusion injury by reducing hepatocyte apoptosis and the inflammatory response through the activation of the CLCF1/STAT3 signaling pathway, offering valuable insights into the impact of MAFF on liver protection and potential therapeutic targets for liver treatment.

The liver as a central "hub" of the immune system: pathophysiological implications

The purpose of this review is to describe the immune function of the liver, guiding the reader from the homeostatic tolerogenic status to the aberrant activation demonstrated in chronic liver disease. An extensive description of the pathways behind the inflammatory modulation of the healthy liver will be provided focusing on the complex immune cell network residing within the liver. The limit of tolerance will be presented in the context of organ transplantation, seizing the limits of homeostatic mechanisms that fail in accepting the graft, progressing eventually toward rejection. The triggers and mechanisms behind chronic activation in metabolic liver conditions and viral hepatitis will be discussed. The last part of the review will be dedicated to one of the greatest paradoxes for a tolerogenic organ, developing autoimmunity. Through the description of the three most common autoimmune liver diseases, the autoimmune reaction against hepatocytes and biliary epithelial cells will be dissected.

Diagnostic value and immune infiltration characterization of WTAP as a critical m6A regulator in liver transplantation

BACKGROUND

RNA N6-methyladenosine (m6A) regulators are essential for numerous biological processes and are implicated in various diseases. However, the comprehensive role of m6A regulators in the context of liver transplantation (LT) remains poorly understood. This study aimed to illustrate the relationship between m6A regulators and ischemia-reperfusion injury (IRI) following LT.

METHODS

Datasets were acquired from the Gene Expression Omnibus database. Differential analysis of the merged data identified the differentially expressed m6A regulators. Random forest (RF) models and nomograms were used to forecast the incidence and assess the IRI risk following LT. m6A regulators were classified into distinct subgroups using cluster analysis. The differential gene expression was validated using immunohistochemistry, immunofluorescence, and Western blotting.

RESULTS

We found significant disparities in the gene expression levels of the three m6A regulators between patients with and without LT. Wilms' tumor 1-associating protein (WTAP) expression was upregulated following LT. The RF models exhibited a high degree of accuracy in predicting IRI risk. Immune infiltration analysis showed that WTAP was an immune-associated m6A regulator that was closely associated with T and B cells. WTAP expression in the rat LT model was upregulated after 24 h of reperfusion, which was consistent with the results of the bioinformatics analysis.

CONCLUSIONS

WTAP has a high diagnostic value for IRI in LT and influences the immune status of patients. Hence, WTAP, as a significant regulator of m6A, is a potential biomarker for the detection and implementation of immunotherapy for IRI following LT.

Biomimetic gene delivery system coupled with extracellular vesicle-encapsulated AAV for improving diabetic wound through promoting vascularization and remodeling of inflammatory microenvironment

Adeno-associated virus (AAV)-mediated gene transfer has demonstrated potential in effectively promoting re-epithelialization and angiogenesis. AAV vector has a safety profile; however, the relatively low delivery efficacy in chronic wound with an inflammatory microenvironment and external exposure has limited its prospective clinical translation. Here, we generated AAV-containing EVs (EV-AAVs) from cultured HEK 293T cells and confirmed that the gene transfer efficiency of VEGF-EV-AAV significantly surpassed that of free AAV. Subsequently, a biomimetic gene delivery system VEGF-EV-AAV/MSC-Exo@FHCCgel developing, and synergistically enhances anti-inflammation and transfection efficiency in the combination of human umbilical cord mesenchymal stem cell-derived exosomes (hUC-MSC-Exo). Upon reaching physiological temperature, this hydrogel system transitions to a gel state, maintaining AAV bioactivity and facilitating a sustained release of the encapsulated vesicles. The encapsulation strategy enables the vesicles to rapidly fuse with endothelial cell membranes, ensuring controlled expression of endogenous VEGF. Results revealed that VEGF-EV-AAV/MSC-Exo@FHCCgel alleviates mitochondrial function in endotheliocyte under oxidative stress. Furthermore, it eliminates senescent macrophages by inhabitation of cyclic GMP-AMP (cGAMP) synthase (cGAS)-stimulator of interferon genes (STING) pathway to promote efferocytosis. The system increases Treg cells accumulation, leading to a reduction of inflammatory cytokines. Collectively, the biomimetic gene delivery system represents a promising multi-faceted strategy for chronic wound healing.

10 degree C static storage of porcine donation after circulatory death livers improves biliary viability and mitigates ischemia-reperfusion injury

Optimized static cold storage has the potential to improve the preservation of organs most vulnerable to ischemia-reperfusion injury. Data from lung transplantation suggest that storage at 10 °C improves mitochondrial preservation and subsequent allograft function compared with conventional storage on ice. Using a porcine model of donation after circulatory death, we compared static storage of livers at 10 °C to ice. Livers (N = 5 per group) underwent 10 hours of storage followed by 4 hours of normothermic machine perfusion (NMP) for real-time allograft assessment. Allografts were compared using established NMP viability criteria, tissue immunostaining, and tissue metabolomics. Livers stored at 10 °C demonstrated lower portal venous vascular resistance and greater hepatic artery vasoresponsiveness. Lactate clearance during NMP was similar between the groups. Livers stored at 10 °C showed favorable biochemical parameters of biliary viability, including greater bile volume, pH, and bicarbonate. Metabolomics analysis revealed increased aerobic respiration, improved electron transport chain function, and less DNA damage after reperfusion of livers stored at 10 °C. Static storage of donation after circulatory death livers with extended cold ischemic time at 10 °C demonstrates superior allograft function with evidence of improved biliary viability and mitochondrial function compared with ice. These data suggest that storage at 10 °C should be considered for translation to clinical practice.

One-step engineered mesenchymal stem cell-derived exosomes against hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury (IRI) is an important factor affecting the prognosis of patients undergoing surgery. Exosomes derived from mesenchymal stem cells (MSC-EXOs) are widely used and play a therapeutic role in hepatic IRI. However, natural exosomes lack liver-targeting ability and have low bioavailability. In this study, MSC-EXOs were simply modified with OPDEA-PCL or liver-targeting DSPE-PEG2000-Galactose, forming OPDEA-PCL-modified MSC-EXOs (OP-EXOs) or DSPE-PEG2000-Galactose-modified MSC-EXOs (GPEG-EXOs). In mouse hepatic IRI model, OP-EXOs and GPEG-EXOs both significantly reduced alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) levels in serum after hepatic IRI, alleviating liver injury. Transcriptomic and proteomic analyses showed that OP-EXOs and GPEG-EXOs reduced hepatic IRI by downregulating the expression of S100A8, S100A9, SELP, and ANXA2 in the liver following IRI. This study opens a new paradigm for the treatment of hepatic IRI using engineered MSC-EXOs with the potential to improve the prognosis of liver surgery.

Identification of biomarkers associated with programmed cell death in liver ischemia-reperfusion injury: insights from machine learning frameworks and molecular docking in multiple cohorts

Introduction

Liver ischemia-reperfusion injury (LIRI) is a major reason for liver injury that occurs during surgical procedures such as hepatectomy and liver transplantation and is a major cause of graft dysfunction after transplantation. Programmed cell death (PCD) has been found to correlate with the degree of LIRI injury and plays an important role in the treatment of LIRI. We aim to comprehensively explore the expression patterns and mechanism of action of PCD-related genes in LIRI and to find novel molecular targets for early prevention and treatment of LIRI.

Methods

We first compared the expression profiles, immune profiles, and biological function profiles of LIRI and control samples. Then, the potential mechanisms of PCD-related differentially expressed genes in LIRI were explored by functional enrichment analysis. The hub genes for LIRI were further screened by applying multiple machine learning methods and Cytoscape. GSEA, GSVA, immune correlation analysis, transcription factor prediction, ceRNA network analysis, and single-cell analysis further revealed the mechanisms and regulatory network of the hub gene in LIRI. Finally, potential therapeutic agents for LIRI were explored based on the CMap database and molecular docking technology.

Results

Forty-seven differentially expressed genes associated with PCD were identified in LIRI, and functional enrichment analysis showed that they were involved in the regulation of the TNF signaling pathway as well as the regulation of hydrolase activity. By utilizing machine learning methods, 11 model genes were identified. ROC curves and confusion matrix from the six cohorts illustrate the superior diagnostic value of our model. MYC was identified as a hub PCD-related target in LIRI by Cytoscape. Finally, BMS-536924 and PF-431396 were identified as potential therapeutic agents for LIRI.

Conclusion

This study comprehensively characterizes PCD in LIRI and identifies one core molecule, providing a new strategy for early prevention and treatment of LIRI.

Ischemia-Reperfusion Injury at Time-Zero Biopsy as a Prognostic Factor in Predicting Liver Graft Outcome in Egyptian Living Donor Liver Transplanted Patients

Background and Aims: Ischemia-reperfusion injury (IRI) is believed to contribute to the early dysfunction of the graft as well as the survival of the patients following liver transplantation (LT). This study is aimed at ascertaining the role of time-zero biopsies in predicting early graft dysfunction and 5-year patient survival after living donor liver transplantation (LDLT). Patients and Methods: From February 2012 to August 2017, time-zero biopsies were obtained from 60 patients. Histological grading of time-zero biopsies was performed to identify the severity of IRI. Patients were divided into two groups: no or minimal to mild IRI versus moderate to severe IRI. Results: Time-zero biopsies of 60 liver allografts revealed no or minimal to mild IRI (n = 38, 63.3%) (Group 1) versus moderate to severe IRI (n = 22, 36.7%) (Group 2). Group 2 recipients indicated a significant increase in serum bilirubin and a higher incidence of early graft dysfunction. There were significant survival differences between the two groups (p = 0.033), and the rate of death was higher in the moderate to severe IRI group. Recipient age, steatosis, and longer CIT were identified as independent predictors of moderate to severe IRI. Conclusion: Time-zero biopsies with moderate to severe IRI upon biopsy can predict adverse clinical outcomes following LT.

The Role of Yes-Associated Protein in Inflammatory Diseases and Cancer

Yes-associated protein (YAP) plays a central role in the Hippo pathway, primarily governing cell proliferation, differentiation, and apoptosis. Its significance extends to tumorigenesis and inflammatory conditions, impacting disease initiation and progression. Given the increasing relevance of YAP in inflammatory disorders and cancer, this study aims to elucidate its pathological regulatory functions in these contexts. Specifically, we aim to investigate the involvement and molecular mechanisms of YAP in various inflammatory diseases and cancers. We particularly focus on how YAP activation, whether through Hippo-dependent or independent pathways, triggers the release of inflammation and inflammatory mediators in respiratory, cardiovascular, and digestive inflammatory conditions. In cancer, YAP not only promotes tumor cell proliferation and differentiation but also modulates the tumor immune microenvironment, thereby fostering tumor metastasis and progression. Additionally, we provide an overview of current YAP-targeted therapies. By emphasizing YAP's role in inflammatory diseases and cancer, this study aims to enhance our understanding of the protein's pivotal involvement in disease processes, elucidate the intricate pathological mechanisms of related diseases, and contribute to future drug development strategies targeting YAP.

Co-exposure to F-53B and nanoplastics induced hepatic glucolipid metabolism disorders by the PI3K-AKT signaling pathway

Recent investigations suggest that the chemical compound F-53B (6:2 chlorinated polyfluorinated ether sulfonate) may pose risks of liver toxicity. Within environmental settings, F-53B attaches to microplastics and nanoplastics, which are capable of being consumed by diverse species. To investigate the synergistic effects on hepatotoxicity, adult male mice were subjected to F-53B at daily doses of 1, 10, and 100 μg/kg, NPs at 100 mg/kg per day, or a combination of both treatments for a duration of 2 months. The results indicated that NPs moderately increased the buildup of F-53B within both the liver and plasma. Co-exposure to F-53B (100 μg/kg/day) and NPs induced hepatocellular edema and elevated plasma ALT levels, which were rarely observed in groups exposed to F-53B or NPs alone. Additionally, we found that co-exposure decreased the concentrations of total cholesterol (TC) and triglycerides (TG) in both plasma and liver tissues, while increasing fasting plasma glucose and insulin levels. Transcriptomic analysis revealed that the PI3K-AKT signaling pathway is potentially involved in mediating hepatic metabolic disorders. Further experiments demonstrated that the combined treatment significantly suppressed the expression of FGF21, an upstream regulator of the PI3K-AKT pathway. This alteration resulted in the suppression of PI3K-regulated gene expression associated with glucose and lipid metabolism. The findings suggest that F-53B impairs hepatic glucolipid metabolism in mice by suppressing of the PI3K-AKT signaling cascade, with NPs amplifying its toxicity.

MLKL as an emerging machinery for modulating organelle dynamics: regulatory mechanisms, pathophysiological significance, and targeted therapeutics

Mixed lineage kinase domain-like protein (MLKL) is a pseudokinase featured by a protein kinase-like domain without catalytic activity. MLKL was originally discovered to be phosphorylated by receptor-interacting protein kinase 1/3, typically increase plasma membrane permeabilization, and disrupt the membrane integrity, ultimately executing necroptosis. Recent evidence uncovers the association of MLKL with diverse cellular organelles, including the mitochondrion, lysosome, endosome, endoplasmic reticulum, and nucleus. Thus, this review mainly focuses on the regulatory functions, mechanisms, and targets of MLKL in organelles rather than necroptosis and summarize the medical significance in multiple diseases. On this basis, we conclude and analyze the current progress and prospect for the development of MLKL-related drugs, from natural products, small-molecule chemical compounds, to proteolysis-targeting chimera. This review is aimed to propel the development of MLKL as a valid drug target and the discovery of novel MLKL-related drugs, and promote their further applications.

Genome-wide KAS-Seq mapping of leukocytes in ischemia-reperfusion model reveals IL7R as a potential therapeutic target for ischemia-reperfusion injury

Ischemia-reperfusion injury (IRI) is one of the leading causes of mortality and disability worldwide. Owing to its complex pathogenesis, there is still a lack of effective therapeutic targets in clinical practice, and exploring the mechanism and targets of IRI is still a major clinical challenge. This study aimed to explore the genetic alterations in leukocytes in peripheral blood after ischemia-reperfusion, aiming to discover new biomarkers and potential therapeutic targets. KAS-Seq (Kethoxal-assisted single-strand DNA sequencing) was used to obtain gene expression profiles of circulating leukocytes in a porcine ischemia-reperfusion model at 24, 48, and 72 h post-ischemia‒reperfusion. This method integrated genes that exhibited regular changes over time. In this study, we thoroughly analyzed the dynamic changes in gene expression post-IRI, revealing significant enrichment in key signaling pathways that regulate immune responses and T-cell activation over time. Our identification of the interleukin-7 receptor (IL7R) was particularly striking, as it plays a crucial molecular role in IRI. Additionally, using database mining technology, we confirmed the close relationship between IL7R and IRI, explored the interaction between interferon-γ (IFNG) and IL7R in T-cell activation, and clarified their joint influence on ischemia-reperfusion injury. Using KAS-Seq analysis of leukocytes from peripheral blood, we successfully delineated the temporal patterns of gene expression and changes in signal transduction pathways in porcine models of ischemia-reperfusion. Subsequent in-depth analysis identified IL7R as a potential novel therapeutic target for IRI. The pivotal role of this gene in modulating immune responses provides innovative avenues for the development of IRI treatments.

Comprehensive analysis of immunogenic cell death-related genes in liver ischemia-reperfusion injury

Background

Liver ischemia-reperfusion injury (LIRI) is a critical condition after liver transplantation. Understanding the role of immunogenic cell death (ICD) may provide insights into its diagnosis and potential therapeutic targets.

Methods

Differentially expressed genes (DEGs) between LIRI and normal samples were identified, and pathway enrichment analyses were performed, followed by immune infiltration assessment through the CIBERSORT method. The consensus clustering analysis was conducted to separate LIRI clusters and single-sample Gene Set Enrichment Analysis (ssGSEA) was used to analyze the distinct immune states between clusters. Weighted Gene Co-Expression Network Analysis (WGCNA) was employed to identify hub genes associated with ICD. To establish diagnostic models, four machine learning techniques, including Random Forest (RF), XGBoost (XGB), Support Vector Machine (SVM), and Generalized Linear Models (GLM), were applied to filter gene sets. The receiver operating characteristic (ROC) curves were utilized to assess the performance of the models.

Results

Pathway enrichment results revealed significant involvement of cytokines and chemokines among DEGs of LIRI. Immune infiltration analysis indicated higher levels of specific immune functions in Cluster 2 compared to Cluster 1. WGCNA identified significant modules linked to LIRI with strong correlations between module membership and gene significance. The RF and SVM machine learning algorithms were finally chosen to construct the models. Both demonstrated high predictive accuracy for diagnosing LIRI not only in training cohort GSE151648 but also in validation cohorts GSE23649 and GSE15480.

Conclusions

The study highlights the pivotal roles of ICD-related genes in LIRI, providing diagnosis models with potential clinical applications for early detection and intervention strategies against LIRI.

Suppression of Hepatocyte Ferroptosis via USP19-Mediated Deubiquitination of SLC7A11 in Ischemia-Free Liver Transplantation

Ischemia-free liver transplantation (IFLT) is developed as a novel clinical approach to avoid ischemia-reperfusion injury (IRI). This study aims to identify the most distinguished programmed cell death pathway in grafts undergoing IFLT versus conventional liver transplantation (CLT) and to explore the underlying mechanism. Ferroptosis is the most distinct programmed cell death form between IFLT and CLT grafts. Among various cell death inhibitors, the ferroptosis inhibitor (Ferrostain-1) is the most effective one to prevent hepatocytes from damage induced by oxygen deprivation/reoxygenation (OGD/R). Hepatocyte ferroptosis is significantly alleviated in IFLT versus CLT grafts in both human beings and pigs. Ubiquitination enzyme screening identifies augmented amounts of ubiquitin-specific protease 19 (USP19) in IFLT versus CLT grafts. The upregulation of USP19 in the grafts is correlated with reduced pathological Suzuki's score, lower post-transplant peak liver enzyme level, and less early allograft dysfunction in liver transplant recipients. USP19 overexpression mitigates post-transplant liver injury in mice. Mechanistically, USP19 inhibits the degradation of solute carrier family 7 member 11 (SLC7A11) by removing its K63-linked ubiquitin chains. Notably, USP19 overexpression reduces ferroptosis and IRI in a SLC7A11-dependent manner in mice. Collectively, USP19-mediated suppression of hepatocyte ferroptosis via deubiquitinating SLC7A11 is a key mechanism by which IFLT abrogates graft IRI.

Milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 (MOP3) attenuates inflammation and improves survival in hepatic ischemia/reperfusion injury

INTRODUCTION

Hepatic ischemia/reperfusion injury is a severe clinical condition leading to high mortality as the result of excessive inflammation, partially triggered by released damage-associated molecular patterns. Extracellular cold-inducible RNA-binding protein is a new damage-associated molecular pattern. Current clinical management of hepatic ischemia/reperfusion injury is limited to supportive therapy, necessitating the development of novel and effective treatment strategies. Milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 is a newly invented oligopeptide originating from milk fat globule-epidermal growth factor-VIII. This peptide acts as an opsonic compound that specifically binds to extracellular cold-inducible RNA-binding protein to facilitate its clearance by phagocytes, thereby attenuating inflammation. In this study, we hypothesized that milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 attenuated hepatic ischemia/reperfusion injury by inhibiting extracellular cold-inducible RNA-binding protein-induced inflammation in Kupffer cells.

METHODS

We treated Kupffer cells isolated from male C57BL/6 mice with extracellular cold-inducible RNA-binding protein and various doses of milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 for 4 hours, then measured cytokines in the culture supernatants. In addition, mice underwent 70% hepatic ischemia for 60 minutes immediately followed by the intravenous administration of either vehicle or milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3. Blood and ischemic liver tissues were collected 24 hours later, and inflammatory markers including cytokines, liver enzymes, chemokines, myeloperoxidase activity, and Z-DNA-binding protein 1 were measured. Hepatic tissue damage and cell death were evaluated histologically. Survival rates were monitored for 10 days posthepatic ischemia/reperfusion.

RESULTS

The release of interleukin-6 and tumor necrosis factor-α from extracellular cold-inducible RNA-binding protein-challenged Kupffer cells was significantly reduced by milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 in a dose-dependent manner. In hepatic ischemia/reperfusion mice, milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 treatment significantly decreased serum levels of extracellular cold-inducible RNA-binding protein, interleukin-6, tumor necrosis factor-α, aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase. Milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 treatment also significantly reduced mRNA levels of interleukin-6, tumor necrosis factor-α, interleukin-1β, Z-DNA-binding protein 1, and chemokine macrophage inflammatory protein-2, as well as myeloperoxidase activity in hepatic tissues. Histologic evaluation demonstrated that treatment with milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 significantly attenuated tissue damage and cell death in the liver of hepatic ischemia/reperfusion mice. Milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 treatment significantly improved the survival rate of hepatic ischemia/reperfusion mice.

CONCLUSION

Milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 significantly attenuated inflammation and liver tissue damage and improved survival after hepatic ischemia/reperfusion. Thus, milk fat globule-epidermal growth factor-VIII-derived oligopeptide 3 holds promise as a potential future therapeutic strategy for hepatic ischemia/reperfusion injury.

Purinergic signaling by TCRαβ+ double-negative T regulatory cells ameliorates liver ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury (HIRI) is an important cause of liver injury following liver transplantation and major resections, and neutrophils are the key effector cells in HIRI. Double-negative T regulatory cells (DNT) are increasingly recognized as having critical regulatory functions in the immune system. Whether DNT expresses distinct immunoregulatory mechanisms to modulate neutrophils, as in HIRI, remains largely unknown. In this study, we found that murine and human DNT highly expressed CD39 that protected DNT from extracellular ATP-induced apoptosis and generated adenosine in tandem with CD73, to induce high levels of neutrophil apoptosis. Furthermore, extracellular adenosine enhanced DNT survival and suppressive function by upregulating survivin and NKG2D expression via the A2AR/pAKT/FOXO1 signaling pathway. Adoptive transfer of DNT ameliorated HIRI in mice through the inhibition of neutrophils in a CD39-dependent manner. Lastly, the adoptive transfer of A2ar-/- DNT validated the importance of adenosine/A2AR signaling, in promoting DNT survival and immunomodulatory function to protect against HIRI in vivo. In conclusion, purinergic signaling is crucial for DNT homeostasis in HIRI. Augmentation of CD39 or activation of A2AR signaling in DNT may provide novel therapeutic strategies to target innate immune disorders.

PLK2 inhibited oxidative stress and ameliorated hepatic ischemia-reperfusion injury through phosphorylating GSK3β

BACKGROUND AND AIM

Hepatic ischemia-reperfusion (I/R) injury is the primary cause of liver dysfunction and liver failure, commonly occurring in liver transplantation, hepatectomy, and hemorrhagic shock. Polo-like kinase 2 (PLK2), a pivotal regulator of centriole duplication, plays a crucial role in cell proliferation and injury repair. However, the function of PLK2 in hepatic I/R remains unclear.

METHODS

The effect of PLK2 was investigated in the mouse hepatic I/R model and the hepatocyte hypoxia-reoxygenation (H/R) model. Liver injury was assessed by serum transaminase and hematoxylin and eosin staining. Cell apoptosis was analyzed using TUNEL analysis and immunoblotting. Inflammatory factors were evaluated by reverse transcription-quantitative polymerase chain reaction. Mice or cultured cells during the I/R or H/R were treated by overexpressing PLK2. ROS fluorescence staining was used to assess oxidative stress injury.

RESULTS

PLK2 was upregulated after hepatic I/R injury. Overexpressed PLK2 significantly improved liver enzyme levels and alleviated liver histological injury. Moreover, PLK2 decreased hepatocyte apoptosis and inhibited the expression of inflammatory factors in liver. Mechanistically, PLK2 increased the phosphorylation of GSK3β and enhanced expression of the antioxidant enzyme HO-1, leading to less ROS production. Inhibition of the HO-1 aggravated ROS generation and abolished the protective effect of PLK2.

CONCLUSION

Overall, these findings revealed that PLK2 enhanced HO-1 expression and reduced oxidative stress damage in hepatic I/R injury, and this protective effect related to GSK3β activity.

Emerging Roles of High-mobility Group Box-1 in Liver Disease

High-mobility group box-1 (HMGB1) is an architectural chromosomal protein with various roles depending on its cellular localization. Extracellular HMGB1 functions as a prototypical damage-associated molecular pattern that triggers inflammation and adaptive immune responses, mediated by specific cell surface receptors, including receptors for advanced glycation end products and toll-like receptors. Post-translational modifications of HMGB1 significantly impact various cellular processes that contribute to the pathogenesis of liver diseases. Recent studies have highlighted the close relationship between HMGB1 and the pathogenesis of acute liver injuries, including acetaminophen-induced liver injury, hepatic ischemia-reperfusion injury, and acute liver failure. In chronic liver diseases, HMGB1 plays a role in nonalcoholic fatty liver disease, alcohol-associated liver disease, liver fibrosis, and hepatocellular carcinoma. Targeting HMGB1 as a therapeutic approach, either by inhibiting its release or blocking its extracellular function, is a promising strategy for treating liver diseases. This review aimed to summarize the available evidence on HMGB1's role in liver disease, focusing on its multifaceted signaling pathways, impact on disease progression, and the translation of these findings into clinical interventions.

Taxifolin attenuates hepatic ischemia-reperfusion injury by enhancing PINK1/Parkin-mediated mitophagy

BACKGROUND

Hepatic ischemia-reperfusion (I/R) injury stands as a recurring clinical challenge in liver transplantation, leading to mitochondrial dysfunction and cellular imbalance. Mitochondria, crucial for hepatocyte metabolism, are significantly damaged during hepatic I/R and the extent of mitochondrial damage correlates with hepatocyte injury. PINK1/Parkin-mediated mitophagy, is a specialized form of cellular autophagy, that maintains mitochondrial quality by identifying and removing damaged mitochondria, thereby restoring cellular homeostasis. Taxifolin (TAX), a natural flavonoid, possesses antioxidant, anti-inflammatory and anticancer properties. This study aimed at investigating the effects of TAX on hepatic I/R and the underlying mechanisms.

METHODS

C57BL/6 mice were pretreated with TAX or vehicle control, followed by 60 min of 70% hepatic ischemia. After 6 h of reperfusion, the mice were euthanized. In vitro, TAX-pretreated primary hepatocytes were subjected to oxygen glucose deprivation/reperfusion (OGD/R).

RESULTS

Hepatic I/R caused mitochondrial damage and apoptosis in hepatocytes, but TAX pretreatment mitigated these effects by normalizing mitochondrial membrane potential and inhibiting reducing apoptotic protein expression. TAX exerted its protective effects by enhancing mitophagy via the PINK1/Parkin pathway. Moreover, silencing the PINK1 gene in primary hepatocytes reversed the beneficial effects of TAX.

CONCLUSION

The results of the study demonstrate that promoting mitophagy through the PINK1/Parkin pathway restores mitochondrial function and protects the liver from I/R, suggesting that it may have therapeutic potential for the treatment of hepatic I/R.

Redox-sensitive epigenetic activation of SUV39H1 contributes to liver ischemia-reperfusion injury

Liver ischemia-reperfusion (I/R) injury is a clinically relevant pathophysiological process that determines the effectiveness of life-saving liver transplantation, to which aberrant ROS accumulation plays a key role. In the present study we investigated the role of SUV39H1, a lysine methyltransferases, in this process focusing on regulatory mechanism and translational potential. We report that SUV39H1 expression was up-regulated in the liver tissues of mice subjected to ischemia-reperfusion and in hepatocytes exposed to hypoxia-reoxygenation (H/R) in a redox-sensitive manner. Mechanistically, coactivator associated arginine methyltransferases 1 (CARM1) mediated redox-sensitive Suv39h1 trans-activation by promoting histone H3R17 methylation. Consistently, pharmaceutical CARM1 inhibition attenuated liver I/R injury. In addition, global or hepatocyte conditional Suv39h1 KO mice were protected from liver I/R injury. RNA-seq revealed that aldehyde dehydrogenase 1 family 1a (Aldh1a1) as a novel target for SUV39H1. SUV39H1 directly bound to the Aldh1a1 promoter and repressed Aldh1a1 transcription in H/R-challenged hepatocytes. ALDH1A1 silencing abrogated the protective effects of SUV39H1 deficiency on H/R-inflicted injuries whereas ALDH1A1 over-expression mitigated liver I/R injury in mice. Importantly, administration of a small-molecule SUV39H1 inhibitor achieved similar hepatoprotective effects as SUV39H1 deletion. Finally, increased Suv39h1 expression and decreased Aldh1a1 expression were observed in liver I/R specimens in humans. In conclusion, our data uncover a regulatory role for SUV39H1 in liver I/R injury and serve as proof-of-concept that targeting the SUV39H1-ALDH1A1 axis might be considered as a reasonable approach for the intervention of liver I/R injury.

Corynoline alleviates hepatic ischemia-reperfusion injury by inhibiting NLRP3 inflammasome activation through enhancing Nrf2/HO-1 signaling

OBJECTIVE

Corynoline has displayed pharmacological effects in reducing oxidative stress and inflammatory responses in many disorders. However, its effects on hepatic ischemia-reperfusion (I/R) injury remain unclear. This study aimed to investigate the protective effects of corynoline against hepatic I/R injury and the underlying mechanisms.

METHODS

Rat models with hepatic I/R injury and BRL-3A cell models with hypoxia/reoxygenation (H/R) insult were constructed. Models were pretreated with corynoline and/or other inhibitors for functional and mechanistic examination.

RESULTS

Corynoline pretreatment effectively mitigated hepatic I/R injury verified by reduced serum transaminase levels, improved histological damage scores, and decreased apoptosis rates. Additionally, corynoline pretreatment significantly inhibited I/R-triggered oxidative stress and inflammatory responses, as indicated by enhanced mitochondrial function, reduced levels of ROS and MDA, reduced neutrophil infiltration and suppressed proinflammatory cytokine release. In vitro experiments further showed that corynoline pretreatment increased cellular viability, decreased LDH activity, reduced cellular apoptosis, and inhibited oxidative stress and inflammatory injury in H/R-induced BRL-3A cells. Mechanistically, corynoline significantly increased Nrf2 nuclear translocation and expression levels of its target gene, HO-1. It also blocked NLRP3 inflammasome activation both in vivo and in vitro. Furthermore, pretreatment with Nrf2 inhibitor ML-385 counteracted the protective effect of corynoline on hepatic I/R injury. Ultimately, in vitro studies revealed that the NLRP3 activator nigericin could also nullified the protective effects of corynoline in BRL-3A cells, but had minimal impact on Nrf2 nuclear translocation.

CONCLUSIONS

Corynoline can exert protective effects against hepatic I/R injury by inhibiting oxidative stress, inflammatory responses, and apoptosis. These effects may be associated with inhibiting ROS-induced NLRP3 inflammasome activation by enhancing Nrf2/HO-1 signaling. These data provide new understanding about the mechanism of corynoline action, suggesting it is a potential drug applied for the treatment and prevention of hepatic I/R injury.

Intraoperative Anesthetic Strategies to Mitigate Early Allograft Dysfunction After Orthotopic Liver Transplantation: A Narrative Review

Orthotopic liver transplantation (OLT) is the most effective treatment for patients with end-stage liver disease (ESLD). Hepatic insufficiency within a week of OLT, termed early allograft dysfunction (EAD), occurs in 20% to 25% of deceased donor OLT recipients and is associated with morbidity and mortality. Primary nonfunction (PNF), the most severe form of EAD, leads to death or retransplantation within 7 days. The etiology of EAD is multifactorial, including donor, recipient, and surgery-related factors, and largely driven by ischemia-reperfusion injury (IRI). IRI is an immunologic phenomenon characterized by dysregulation of cellular oxygen homeostasis and innate immune defenses in the allograft after temporary cessation (ischemia) and later restoration (reperfusion) of oxygen-rich blood flow. The rising global demand for OLT may lead to the use of marginal allografts, which are more susceptible to IRI, and thus lead to an increased incidence of EAD. It is thus imperative the anesthesiologist is knowledgeable about EAD, namely its pathophysiology and intraoperative strategies to mitigate its impact. Intraoperative strategies can be classified by 3 phases, specifically donor allograft procurement, storage, and recipient reperfusion. During procurement, the anesthesiologist can use pharmacologic preconditioning with volatile anesthetics, consider preharvest hyperoxemia, and attenuate the use of norepinephrine as able. The anesthesiologist can advocate for normothermic regional perfusion (NRP) and machine perfusion during allograft storage at their institution. During recipient reperfusion, the anesthesiologist can optimize oxygen exposure, consider adjunct anesthetics with antioxidant-like properties, and administer supplemental magnesium. Unfortunately, there is either mixed, little, or no data to support the routine use of many free radical scavengers. Given the sparse, limited, or at times conflicting evidence supporting some of these strategies, there are ample opportunities for more research to find intraoperative anesthetic strategies to mitigate the impact of EAD and improve postoperative outcomes in OLT recipients.

Innovative hydrogel-based therapies for ischemia-reperfusion injury： bridging the gap between pathophysiology and treatment

Ischemia-reperfusion injury (IRI) commonly occurs in clinical settings, particularly in medical practices such as organ transplantation, cardiopulmonary resuscitation, and recovery from acute trauma, posing substantial challenges in clinical therapies. Current systemic therapies for IRI are limited by poor drug targeting, short efficacy, and significant side effects. Owing to their exceptional biocompatibility, biodegradability, excellent mechanical properties, targeting capabilities, controlled release potential, and properties mimicking the extracellular matrix (ECM), hydrogels not only serve as superior platforms for therapeutic substance delivery and retention, but also facilitate bioenvironment cultivation and cell recruitment, demonstrating significant potential in IRI treatment. This review explores the pathological processes of IRI and discusses the roles and therapeutic outcomes of various hydrogel systems. By categorizing hydrogel systems into depots delivering therapeutic agents, scaffolds encapsulating mesenchymal stem cells (MSCs), and ECM-mimicking hydrogels, this article emphasizes the selection of polymers and therapeutic substances, and details special crosslinking mechanisms and physicochemical properties, as well as summarizes the application of hydrogel systems for IRI treatment. Furthermore, it evaluates the limitations of current hydrogel treatments and suggests directions for future clinical applications.

Fangchinoline protects hepatic ischemia/reperfusion liver injury in rats through anti-oxidative stress and anti-inflammation properties: an in silico study

Liver ischemia-reperfusion (I/R) injury is a common cause of organ failure, developed by a sudden block in the blood and oxygen supply and subsequent restoration. I/R damage is responsible for acute and chronic rejection after organ transplantation, accounting for 10% of early graft failure. The study investigated the therapeutic properties of fangchinoline in liver injury-induced rats. The rats were divided into three groups: Sham, I/R without pretreatment, and I/R + 10 mg/kg fangchinoline pretreatment. Blood and liver samples were collected for assays, and an in silico docking analysis was conducted to determine fangchinoline's inhibitory effect. The pretreatment with 10 mg/kg of fangchinoline effectively reduced hepatic marker enzymes such as AST, LDH, and ALT in the serum of rats with liver I/R damage. Fangchinoline treatment significantly reduced interleukin-8 (IL-8), IL-6, and tumor necrosis factor-α (TNF-α) in I/R-induced rats, boosting antioxidants and decreasing MDA. Histopathological studies showed liver injury protection, and fangchinoline inhibited TNF-α and IL-6 with improved binding affinity. Fangchinoline has hepatoprotective properties by reducing inflammation in rats with liver I/R damage, as demonstrated in the current study. Hence, it can be an effective salutary agent in preventing liver damage caused by I/R.

Biological and clinical role of TREM2 in liver diseases

Liver diseases constitute a major health burden worldwide, accounting for more than 4% of all disease-related mortalities. While the incidence of viral hepatitis is expected to decrease, metabolic liver disorders are increasingly diagnosed. Liver pathology is diverse, with functional and molecular alterations in both parenchymal and mesenchymal cells, including immune cells. Triggering receptor expressed on myeloid cells 2 (TREM2) is a transmembrane receptor of the immunoglobulin superfamily and mainly expressed on myeloid cells. Several studies have demonstrated that TREM2 plays a critical role in tissue physiology and various pathological conditions. TREM2 is recognized as being associated with the development of liver diseases by regulating tissue homeostasis and the immune microenvironment. The biological and clinical impact of TREM2 is complex, given its diverse context-dependent functions. This review aims to summarize recent progress in understanding the association between TREM2 and different liver disorders and shed light on the clinical significance of targeting TREM2.

Exploring the effects of hypoxia and reoxygenation time on hepatocyte apoptosis and inflammation

Hepatic Ischemia-Reperfusion Injury (HIRI) is an unavoidable pathological process during liver surgeries such as liver transplantation and hepatic resection, which involves a complex set of molecular and cellular mechanisms. The mechanisms of HIRI may involve a variety of biological processes in which inflammation and apoptosis play a central role. Therefore, it is crucial to deeply investigate the effects of different hypoxia and reoxygenation times on the construction of an in vitro model of hepatic ischemia-reperfusion injury. The human normal liver cell line HL-7702 IRI model was constructed by hypoxia chamber, and the inflammation and apoptosis focal levels of cells were detected by enzyme-linked immunosorbent assay, western blot and quantitative reverse transcription polymerase chain reaction. When 12-hour reoxygenation time was fixed, the inflammation and apoptosis indexes of HIRI model increased with the prolongation of hypoxia time (6, 12 and 24 hours). These indices reached highest level in the model group of 24-hour fixed hypoxia and 12-hour reoxygenation. Inflammation and apoptosis indices were significantly higher in the model group of 24-hours fixed hypoxia and 12-hours reoxygenation than in the group of 6 and 24 hours of reoxygenation. Taken together, the findings from this research demonstrated that during hypoxia phase, cells exhibited a clear time-dependent response of inflammation and cell death; on the contrary, during the reoxygenation phase, the cellular damage was not monotonically incremental, but showed an inverted U-shaped dynamic pattern. The present study reveals in depth the dynamic changes of cellular responses under hypoxia and reoxygenation conditions, providing us with an important theoretical basis to guide the selection and optimization of in vitro experimental models.

Chemical approaches targeting the hurdles of hepatocyte transplantation: mechanisms, applications, and advances

Hepatocyte transplantation (HTx) has been a novel cell-based therapy for severe liver diseases, as the donor livers for orthotopic liver transplantation are of great shortage. However, HTx has been confronted with two main hurdles: limited high-quality hepatocyte sources and low cell engraftment and repopulation rate. To cope with, researchers have investigated on various strategies, including small molecule drugs with unique advantages. Small molecules are promising chemical tools to modulate cell fate and function for generating high quality hepatocyte sources. In addition, endothelial barrier, immune responses, and low proliferative efficiency of donor hepatocytes mainly contributes to low cell engraftment and repopulation rate. Interfering these biological processes with small molecules is beneficial for improving cell engraftment and repopulation. In this review, we will discuss the applications and advances of small molecules in modulating cell differentiation and reprogramming for hepatocyte resources and in improving cell engraftment and repopulation as well as its underlying mechanisms.

Current status and perspective on molecular targets and therapeutic intervention strategy in hepatic ischemia-reperfusion injury

Hepatic ischemia‒reperfusion injury (HIRI) is a common and inevitable complication of hepatic trauma, liver resection, or liver transplantation. It contributes to postoperative organ failure or tissue rejection, eventually affecting patient prognosis and overall survival. The pathological mechanism of HIRI is highly complex and has not yet been fully elucidated. The proposed underlying mechanisms include mitochondrial damage, oxidative stress imbalance, abnormal cell death, immune cell hyperactivation, intracellular inflammatory disorders and other complex events. In addition to serious clinical limitations, available antagonistic drugs and specific treatment regimens are still lacking. Therefore, there is an urgent need to not only clarify the exact etiology of HIRI but also reveal the possible reactions and bottlenecks of existing drugs, helping to reduce morbidity and shorten hospitalizations. We analyzed the possible underlying mechanism of HIRI, discussed various outcomes among different animal models and explored neglected potential therapeutic strategies for HIRI treatment. By thoroughly reviewing and analyzing the literature on HIRI, we gained a comprehensive understanding of the current research status in related fields and identified valuable references for future clinical and scientific investigations.

Innovative Strategies for Liver Transplantation: The Role of Mesenchymal Stem Cells and Their Cell-Free Derivatives

Despite being the standard treatment for end-stage liver disease, liver transplantation has limitations like donor scarcity, high surgical costs, and immune rejection risks. Mesenchymal stem cells (MSCs) and their derivatives offer potential for liver regeneration and transplantation. MSCs, known for their multipotency, low immunogenicity, and ease of obtainability, can differentiate into hepatocyte-like cells and secrete bioactive factors that promote liver repair and reduce immune rejection. However, the clinical application of MSCs is limited by risks such as aberrant differentiation and low engraftment rates. As a safer alternative, MSC-derived secretomes and extracellular vesicles (EVs) offer promising therapeutic benefits, including enhanced graft survival, immunomodulation, and reduced ischemia-reperfusion injury. Current research highlights the efficacy of MSC-derived therapies in improving liver transplant outcomes, but further studies are necessary to standardize clinical applications. This review highlights the potential of MSCs and EVs to address key challenges in liver transplantation, paving the way for innovative therapeutic strategies.

Rethinking Immune Check Point Inhibitors Use in Liver Transplantation: Implications and Resistance

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy, including the two most common liver tumors, hepatocellular carcinoma and cholangiocarcinoma, but their use in the peri-transplantation period is controversial. ICI therapy aims to heighten cytotoxic T lymphocytes response against tumors. However, tumor recurrence is common owing to tumor immune response escape involving ablation of CTL response by interfering with antigen presentation, triggering CLT apoptosis and inducing epigenetic changes that promote ICI therapy resistance. ICI can also affect tissue resident memory T cell population, impact tolerance in the post-transplant period, and induce acute inflammation risking graft survival post-transplant. Their interaction with immunosuppression may be key in reducing tumor burden and may thus, require multimodal therapy to treat these tumors. This review summarizes ICI use in the liver transplantation period, their impact on tolerance and resistance, and new potential therapies for combination or sequential treatments for liver tumors.

Oleanolic acid alleviating ischemia-reperfusion injury in rat severe steatotic liver via KEAP1/NRF2/ARE

Severe steatosis in donor livers is contraindicated for transplantation due to the high risk of ischemia-reperfusion injury (IRI). Although Ho-1 gene-modified bone marrow mesenchymal stem cells (HO-1/BMMSCs) can mitigate IRI, the role of gut microbiota and metabolites in this protection remains unclear. This study aimed to explore how gut microbiota and metabolites contribute to HO-1/BMMSCs-mediated protection against IRI in severe steatotic livers. Using rat models and cellular models (IAR20 and THLE-2 cells) of steatotic liver IRI, this study revealed that ischemia-reperfusion led to significant liver and intestinal damage, heightened immune responses, impaired liver function, and altered gut microbiota and metabolite profiles in rats with severe steatosis, which were partially reversed by HO-1/BMMSCs transplantation. Integrated microbiome and metabolome analyses identified gut microbial metabolite oleanolic acid as a potential protective agent against IRI. Experimental validation showed that oleanolic acid administration alone alleviated IRI and inhibited ferroptosis in both rat and cellular models. Network pharmacology and molecular docking implicated KEAP1/NRF2 pathway as a potential target of oleanolic acid. Indeed, OA experimentally upregulated NRF2 activity, which underlies its inhibition of ferroptosis and protection against IRI. The gut microbial metabolite OA protects against IRI in severe steatotic liver by promoting NRF2 expression and activity, thereby inhibiting ferroptosis.

Leukocyte cell-derived chemotaxin 2 (LECT2) regulates liver ischemia-reperfusion injury

Background and aim

Hepatic ischemia-reperfusion injury (IRI) is a significant challenge in liver transplantation, trauma, hypovolemic shock, and hepatectomy, with limited effective interventions available. This study aimed to investigate the role of leukocyte cell-derived chemotaxin 2 (LECT2) in hepatic IRI and assess the therapeutic potential of Lect2-short hairpin RNA (shRNA) delivered through adeno-associated virus (AAV) vectors.

Materials and methods

This study analyzed human liver and serum samples from five patients undergoing the Pringle maneuver. Lect2-knockout and C57BL/6J mice were used. Hepatic IRI was induced by clamping the hepatic pedicle. Treatments included recombinant human LECT2 (rLECT2) and AAV-Lect2-shRNA. LECT2 expression levels and serum biomarkers including alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, and blood urea nitrogen (BUN) were measured. Histological analysis of liver necrosis and quantitative reverse-transcription polymerase chain reaction were performed.

Results

Serum and liver LECT2 levels were elevated during hepatic IRI. Serum LECT2 protein and mRNA levels increased post reperfusion. Lect2-knockout mice had reduced weight loss; hepatic necrosis; and serum ALT, AST, creatinine, and BUN levels. rLECT2 treatment exacerbated weight loss, hepatic necrosis, and serum biomarkers (ALT, AST, creatinine, and BUN). AAV-Lect2-shRNA treatment significantly reduced weight loss, hepatic necrosis, and serum biomarkers (ALT, AST, creatinine, and BUN), indicating therapeutic potential.

Conclusions

Elevated LECT2 levels during hepatic IRI increased liver damage. Genetic knockout or shRNA-mediated knockdown of Lect2 reduced liver damage, indicating its therapeutic potential. AAV-mediated Lect2-shRNA delivery mitigated hepatic IRI, offering a potential new treatment strategy to enhance clinical outcomes for patients undergoing liver-related surgeries or trauma.

ZLN005, a PGC-1α Activator, Protects the Liver against Ischemia-Reperfusion Injury and the Progression of Hepatic Metastases

BACKGROUND

Exercise can promote sustainable protection against cold and warm liver ischemia-reperfusion injury (IRI) and tumor metastases. We have shown that this protection is by the induction of hepatic mitochondrial biogenesis pathway. In this study, we hypothesize that ZLN005, a PGC-1α activator, can be utilized as an alternative therapeutic strategy.

METHODS

Eight-week-old mice were pretreated with ZLN005 and subjected to liver warm IRI. To establish a liver metastatic model, MC38 cancer cells (1 × 106) were injected into the spleen, followed by splenectomy and liver IRI.

RESULTS

ZLN005-pretreated mice showed a significant decrease in IRI-induced tissue injury as measured by serum ALT/AST/LDH levels and tissue necrosis. ZLN005 pretreatment decreased ROS generation and cell apoptosis at the site of injury, with a significant decrease in serum pro-inflammatory cytokines, innate immune cells infiltration, and intrahepatic neutrophil extracellular trap (NET) formation. Moreover, mitochondrial mass was significantly upregulated in hepatocytes and maintained after IRI. This was confirmed in murine and human hepatocytes treated with ZLN005 in vitro under normoxic and hypoxic conditions. Additionally, ZLN005 preconditioning significantly attenuated tumor burden and increased the percentage of intratumoral cytotoxic T cells.

CONCLUSIONS

Our study highlights the effective protection of ZLN005 pretreatment as a therapeutic alternative in terms of acute liver injury and tumor metastases.

Pathogenesis and interaction of neutrophils and extracellular vesicles in noncancer liver diseases

Liver disease ranks as the eleventh leading cause of mortality, leading to approximately 2 million deaths annually worldwide. Neutrophils are a type of immune cell that are abundant in peripheral blood and play a vital role in innate immunity by quickly reaching the site of liver injury. They exert their influence on liver diseases through autocrine, paracrine, and immunomodulatory mechanisms. Extracellular vesicles, phospholipid bilayer vesicles, transport a variety of substances, such as proteins, nucleic acids, lipids, and pathogenic factors, for intercellular communication. They regulate cell communication and perform their functions by delivering biological information. Current research has revealed the involvement of the interaction between neutrophils and extracellular vesicles in the pathogenesis of liver disease. Moreover, more research has focused on targeting neutrophils as a therapeutic strategy to attenuate disease progression. Therefore, this article summarizes the roles of neutrophils, extracellular vesicles, and their interactions in noncancerous liver diseases.

Graft repair during machine perfusion: a current overview of strategies

PURPOSE OF REVIEW

With changing donor characteristics (advanced age, obesity), an increase in the use of extended criteria donor (ECD) livers in liver transplantation is seen. Machine perfusion allows graft viability assessment, but still many donor livers are considered nontransplantable. Besides being used as graft viability assessment tool, ex situ machine perfusion offers a platform for therapeutic strategies to ameliorate grafts prior to transplantation. This review describes the current landscape of graft repair during machine perfusion.

RECENT FINDINGS

Explored anti-inflammatory therapies, including inflammasome inhibitors, hemoabsorption, and cellular therapies mitigate the inflammatory response and improve hepatic function. Cholangiocyte organoids show promise in repairing the damaged biliary tree. Defatting during normothermic machine perfusion shows a reduction of steatosis and improved hepatobiliary function compared to nontreated livers. Uptake of RNA interference therapies during machine perfusion paves the way for an additional treatment modality.

SUMMARY

The possibility to repair injured donor livers during ex situ machine perfusion might increase the utilization of ECD-livers. Application of defatting agents is currently explored in clinical trials, whereas other therapeutics require further research or optimization before entering clinical research.

Nanotechnology-based Strategies for Molecular Imaging, Diagnosis, and Therapy of Organ Transplantation

Organ transplantation is the preferred paradigm for patients with end-stage organ failures. Despite unprecedented successes, complications such as immune rejection, ischemia-reperfusion injury, and graft dysfunction remain significant barriers to long-term recipient survival after transplantation. Conventional immunosuppressive drugs have limited efficacy because of significant drug toxicities, high systemic immune burden, and emergence of transplant infectious disease, leading to poor quality of life for patients. Nanoparticle-based drug delivery has emerged as a promising medical technology and offers several advantages by enhancing the delivery of drug payloads to their target sites, reducing systemic toxicity, and facilitating patient compliance over free drug administration. In addition, nanotechnology-based imaging approaches provide exciting diagnostic methods for monitoring molecular and cellular changes in transplanted organs, visualizing immune responses, and assessing the severity of rejection. These noninvasive technologies are expected to help enhance the posttransplantation patient survival through real time and early diagnosis of disease progression. Here, we present a comprehensive review of nanotechnology-assisted strategies in various aspects of organ transplantation, including organ protection before transplantation, mitigation of ischemia-reperfusion injury, counteraction of immune rejection, early detection of organ dysfunction posttransplantation, and molecular imaging and diagnosis of immune rejection.

TMEM79 Ameliorates Cerebral Ischemia/Reperfusion Injury Through Regulating Inflammation and Oxidative Stress via the Nrf2/NLRP3 Pathway

BACKGROUND

Cerebral ischemia/reperfusion injury (CIRI) is still a complicated disease with high fatality rates worldwide. Transmembrane Protein 79 (TMEM79) regulates inflammation and oxidative stress in some other diseases.

METHODS

CIRI mouse model was established using C57BL/6J mice through middle cerebral artery occlusion-reperfusion (MCAO/R), and BV2 cells were subjected to oxygen and glucose deprivation/reoxygenation (OGD/R) to simulate CIRI. Brain tissue or BV2 cells were transfected or injected with lentivirus-carried TMEM79 overexpression vector. The impact of TMEM79 on CIRI-triggered oxidative stress was ascertained by dihydroethidium (DHE) staining and examination of oxidative stress indicators. Regulation of TMEM79 in neuronal apoptosis and inflammation was determined using TUNEL staining and ELISA.

RESULTS

TMEM79 overexpression mitigated neurological deficit induced by MCAO/R and decreased the extent of cerebral infarct. TMEM79 prevented neuronal death in brain tissue of MCAO/R mouse model and suppressed inflammatory response by reducing inflammatory cytokines levels. Moreover, TMEM79 significantly attenuated inflammation and oxidative stress caused by OGD/R in BV2 cells. TMEM79 facilitated the activation of Nrf2 and inhibited NLRP3 and caspase-1 expressions. Rescue experiments indicated that the Nrf2/NLRP3 signaling pathway mediated the mitigative effect of TMEM79 on CIRI in vivo and in vitro.

CONCLUSION

Overall, TMEM79 was confirmed to attenuate CIRI via regulating the Nrf2/NLRP3 signaling pathway.

SEA Alleviates Hepatic Ischaemia-Reperfusion Injury by Promoting M2 Macrophage Polarisation

Hepatic ischaemia-reperfusion (I/R) injury is a frequent and nearly inevitable pathophysiological process without widely accepted effective therapy. Soluble egg antigen (SEA) of Schistosoma japonicum (S. japonicum) is the main mediators capable of regulating immunological activities and has received increased attention in immune-mediated diseases. But its role in hepatic I/R injury has not been well defined. This study aimed to elucidate whether SEA protects liver against hepatic I/R injury and explore underlying mechanism. After intraperitoneal injecting SEA three times a week for 4 weeks, mice underwent 70% hepatic I/R injury. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), haematoxylin-eosin (HE) and TdT-mediated dUTP nick-end labelling (TUNEL) staining were used to evaluate liver injury. The severity related to the inflammatory response was also investigated. Furthermore, immunofluorescence was used to detect macrophage polarisation. Compared with the hepatic I/R injury group, SEA pretreatment significantly alleviated hepatic I/R injury induced liver damage, apoptosis and inflammatory. Interestingly, SEA enhanced the polarisation of macrophages towards M2 macrophages in vivo. We are the first to investigate the therapeutic efficacy of S. japonicum SEA in a hepatic I/R injury model in mice. We provided the first direct evidence that SEA attenuated hepatic I/R injury by promoting M2 macrophage polarisation.

Systemic mechanisms of necrotic cell debris clearance

Necrosis is an overarching term that describes cell death modalities caused by (extreme) adverse conditions in which cells lose structural integrity. A guaranteed consequence of necrosis is the production of necrotic cell remnants, or debris. Necrotic cell debris is a strong trigger of inflammation, and although inflammatory responses are required for tissue healing, necrotic debris may lead to uncontrolled immune responses and collateral damage. Besides local phagocytosis by recruited leukocytes, there is accumulating evidence that extracellular mechanisms are also involved in necrotic debris clearance. In this review, we focused on systemic clearance mechanisms present in the bloodstream and vasculature that often cooperate to drive the clearance of cell debris. We reviewed the contribution and cooperation of extracellular DNases, the actin-scavenger system, the fibrinolytic system and reticuloendothelial cells in performing clearance of necrotic debris. Moreover, associations of the (mis)functioning of these clearance systems with a variety of diseases were provided, illustrating the importance of the mechanisms of clearance of dead cells in the organism.

Mid1 aggravates hepatic ischemia-reperfusion injury by inducing immune cell infiltration

Hepatic ischemia-reperfusion injury (HIRI) represents a major risk factor in liver transplantation and resection surgeries. Kupffer cells (KCs) produce proinflammatory cytokines and lead to hepatic neutrophil infiltration in the liver, which is one of the leading causes of HIRI. Mid1 is involved in immune infiltration, but the role of Mid1 remains poorly understood. Herin, our study aimed to investigate the effect of Mid1 on HIRI progression. Male C57BL/6 mice aged 6 weeks were used for the HIRI model established. The function of Mid1 on liver injury and hepatic inflammation was evaluated. In vitro, KCs were used to investigate the function and mechanism of Mid1 in modulating KC inflammation upon lipopolysaccharide (LPS) stimulation. We found that Mid1 expression was up-regulated upon HIRI. Mid1 inhibition alleviated liver damage, as evidenced by neutrophil infiltration, intrahepatic inflammation, and hepatocyte apoptosis. In vitro experiments further revealed that Mid1 knockdown reduced the secretion of proinflammatory cytokines and chemokines in KCs. Moreover, silenced-Mid1 suppressed proinflammatory responses by the inhibition of NF-κB, JNK, and p38 signaling pathways. Taken together, Mid1 contributes to HIRI via regulating the proinflammatory response of KCs and inducing neutrophil infiltration. Targeting Mid1 may be a promising strategy to protect against HIRI.

Hepatic microcirculatory disturbance in liver diseases: intervention with traditional Chinese medicine

The liver, a complex parenchymal organ, possesses a distinctive microcirculatory system crucial for its physiological functions. An intricate interplay exists between hepatic microcirculatory disturbance and the manifestation of pathological features in diverse liver diseases. This review updates the main characteristics of hepatic microcirculatory disturbance, including hepatic sinusoidal capillarization, narrowing of sinusoidal space, portal hypertension, and pathological angiogenesis, as well as their formation mechanisms. It also summarized the detection methods for hepatic microcirculation. Simultaneously, we have also reviewed the characteristics of microcirculatory disturbance in diverse liver diseases such as acute liver failure, hepatic ischemia-reperfusion injury, viral hepatitis, non-alcoholic fatty liver disease, hepatic fibrosis, hepatic cirrhosis, and hepatocellular carcinoma. Finally, this review also summarizes the advancement in hepatic microcirculation attributed to traditional Chinese medicine (TCM) and its active metabolites, providing novel insights into the application of TCM in treating liver diseases.

Pim-1 kinase protects the liver from ischemia reperfusion injury by regulating dynamics-related protein 1

Hepatic ischemia-reperfusion (IR) injury significantly impacts liver transplantation success, yet current treatments remain inadequate. This study explores the role of Proto-oncogene serine/threonine-protein kinase (Pim-1) in liver IR, an area previously unexplored. Utilizing a mouse liver IR in vivo model and a MIHA cell hypoxia-reoxygenation in vitro model, we observed that Pim-1 expression increases following IR, inversely correlating with serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Increased Pim-1 expression stabilizes mitochondrial membranes by modifying Drp1 phosphorylation, reducing mitochondrial fission and apoptosis, thereby mitigating liver damage. Additionally, we discovered that elevated Pim-1 expression is dependent on the trimethylation of histone H3 lysine 9 during liver IR. These findings underscore the importance and potential clinical application of targeting Pim-1 in treating hepatic IR, presenting a novel therapeutic avenue.

Programmed cell death, from liver Ischemia-Reperfusion injury perspective: An overview

Liver ischemia-reperfusion injury (LIRI) commonly occurs in liver resection, liver transplantation, shock, and other hemorrhagic conditions, resulting in profound local and systemic effects via associated inflammatory responses and hepatic cell death. Hepatocyte death is a significant component of LIRI and its mechanism was previously thought to be limited to apoptosis and necrosis. With the discovery of novel types of programmed cell death (PCD), necroptosis, ferroptosis, pyroptosis, autophagy, NETosis, and parthanatos have been shown to be involved in LIRI. Understanding the mechanisms underlying cell death following LIRI is indispensable to mitigating the widespread effects of LIRI. Here, we review the roles of different PCD and discuss potential therapy in LIRI.