Acute Liver Failure Model Research Articles

Model of Acute Liver Failure in an Isolated Perfused Porcine Liver—Challenges and Lessons Learned

Acute liver failure (ALF) is a rare but devastating disease associated with substantial morbidity and a mortality rate of almost 45%. Medical treatments, apart from supportive care, are limited and liver transplantation may be the only rescue option. Large animal models, which most closely represent human disease, can be logistically and technically cumbersome, expensive and pose ethical challenges. The development of isolated organ perfusion technologies, originally intended for preservation before transplantation, offers a new platform for experimental models of liver disease, such as ALF. In this study, female domestic swine underwent hepatectomy, followed by perfusion of the isolated liver on a normothermic machine perfusion device. Five control livers were perfused for 24 h at 37 °C, while receiving supplemental oxygen and nutrition. Six livers received toxic doses of acetaminophen given over 12 h, titrated to methemoglobin levels. Perfusate was sampled every 4 h for measurement of biochemical markers of injury (e.g., aspartate aminotransferase [AST], alanine aminotransferase [ALT]). Liver biopsies were taken at the beginning, middle, and end of perfusion for histological assessment. Acetaminophen-treated livers received a median dose of 8.93 g (8.21–9.75 g) of acetaminophen, achieving a peak acetaminophen level of 3780 µmol/L (3189–3913 µmol/L). Peak values of ALT (76 vs. 105 U/L; p = 0.429) and AST (3576 vs. 4712 U/L; p = 0.429) were not significantly different between groups. However, by the end of perfusion, histology scores were significantly worse in the acetaminophen treated group (p = 0.016). All acetaminophen treated livers developed significant methemoglobinemia, with a peak methemoglobin level of 19.3%, compared to 2.0% for control livers (p = 0.004). The development of a model of ALF in the ex vivo setting was confounded by the development of toxic methemoglobinemia. Further attempts using alternative agents or dosing strategies may be warranted to explore this setting as a model of liver disease.

A non-human primate model of acute liver failure suitable for testing liver support systems.

Acute hepatic failure is associated with high morbidity and mortality for which the only definitive therapy is liver transplantation. Some fraction of those who undergo emergency transplantation have been shown to recover native liver function when transplanted with an auxiliary hepatic graft that leaves part of the native liver intact. Thus, transplantation could have been averted with the development and use of some form of hepatic support. The costs of developing and testing liver support systems could be dramatically reduced by the availability of a reliable large animal model of hepatic failure with a large therapeutic window that allows the assessment of efficacy and timing of intervention. Non-lethal forms of hepatic injury were examined in combination with liver-directed radiation in non-human primates (NHPs) to develop a model of acute hepatic failure that mimics the human condition. Porcine hepatocyte transplantation was then tested as a potential therapy for acute hepatic failure. After liver-directed radiation therapy, delivery of a non-lethal hepatic ischemia-reperfusion injury reliably and rapidly generated liver failure providing conditions that can enable pre-clinical testing of liver support or replacement therapies. Unfortunately, in preliminary studies, low hepatocyte engraftment and over-immune suppression interfered with the ability to assess the efficacy of transplanted porcine hepatocytes in the model. A model of acute liver failure in NHPs was created that recapitulates the pathophysiology and pathology of the clinical condition, does so with reasonably predictable kinetics, and results in 100% mortality. The model allowed preliminary testing of xenogeneic hepatocyte transplantation as a potential therapy.

Deficiency of Ninjurin1 attenuates LPS/D-galactosamine-induced acute liver failure by reducing TNF-α-induced apoptosis in hepatocytes.

Nerve injury‐induced protein 1 (Ninjurin1, Ninj1) is a membrane protein that mediates cell adhesion. The role of Ninj1 during inflammatory response has been widely investigated in macrophages and endothelial cells. Ninj1 is expressed in various tissues, and the liver also expresses high levels of Ninj1. Although the hepatic upregulation of Ninj1 has been reported in human hepatocellular carcinoma and septic mice, little is known of its function during the pathogenesis of liver diseases. In the present study, the role of Ninj1 in liver inflammation was explored using lipopolysaccharide (LPS)/D‐galactosamine (D‐gal)‐induced acute liver failure (ALF) model. When treated with LPS/D‐gal, conventional Ninj1 knock‐out (KO) mice exhibited a mild inflammatory phenotype as compared with wild‐type (WT) mice. Unexpectedly, myeloid‐specific Ninj1 KO mice showed no attenuation of LPS/D‐gal‐induced liver injury. Whereas, Ninj1 KO primary hepatocytes were relatively insensitive to TNF‐α‐induced caspase activation as compared with WT primary hepatocytes. Also, Ninj1 knock‐down in L929 and AML12 cells and Ninj1 KO in HepG2 cells ameliorated TNF‐α‐mediated apoptosis. Consistent with in vitro results, hepatocyte‐specific ablation of Ninj1 in mice alleviated LPS/D‐gal‐induced ALF. Summarizing, our in vivo and in vitro studies show that lack of Ninj1 in hepatocytes diminishes LPS/D‐gal‐induced ALF by alleviating TNF‐α/TNFR1‐induced cell death.

Chrysophanol-8-O-glucoside protects mice against acute liver injury by inhibiting autophagy in hepatic stellate cells and inflammatory response in liver-resident macrophages.

Acute liver failure (ALF) is an unfavorable condition characterized by the rapid loss of liver function and high mortality. Chrysophanol-8-O-glucoside (CPOG) is an anthraquinone derivative isolated from rhubarb. This study aims to evaluate the protective effect of CPOG on lipopolysaccharide (LPS)/D-GalN-induced ALF and its underlying mechanisms. LPS/D-GalN-induced mice ALF model and LPS treatment model in RAW 264.7 and LX2 cells were established. It was found that CPOG ameliorated LPS/D-GalN-induced liver injury and improved mortality as indicated by Hematoxylin-eosin (H&E) staining. Molecularly, qPCR and ELISA results showed that CPOG alleviated LPS/D-GalN-induced release of alanine aminotransferase and aspartate transaminase and the secretion of TNF-α and IL-1β in vivo. LPS/D-GalN-induced intracellular ROS production was also attenuated by CPOG in liver tissue. Further, CPOG attenuated ROS generation and inhibited the expression of p-IκB and p-p65 as well as the expression of TNF-α and IL-1β stimulated by LPS in RAW 264.7 cells. In addition, CPOG alleviated LPS-induced up-regulation of LC3B, p62, ATG5 and Beclin1 by attenuating ROS production and inhibiting MAPK signaling in LX2 cells. Taken together, our data indicated that the CPOG protected against LPS/D-GalN-induced ALF by inhibiting oxidative stress, inflammation response and autophagy. These findings suggest that CPOG could be potential drug for the treatment of ALF in clinic.

Dynamics of Acute Liver Injury in Experimental Models of Hepatotoxicity in the Context of Their Implementation in Preclinical Studies on Stem Cell Therapy.

Experimental models using carbon tetrachloride (CCl4) and D-galactosamine (D-GalN) can be used in preclinical assessment of acute liver failure (ALF) therapies. Unfortunately, these models are characterized by different dynamics of liver injury depending on the animal strain, administered hepatotoxin, and its dose. The aim of this study was to compare known rat and mouse models of ALF with a view to their future introduction into preclinical cell therapy experiments. In particular, based on histopathological and molecular changes, we suggested experimental time cut-off points for an effective stem cell therapeutic intervention. ALF was induced by a single intraperitoneal injection of CCl4 in mice (50 μL/100 g b.w.) and rats (200 μL/100 g b.w.) and D-GalN in mice (150 mg/100 g b.w.) and rats (50 mg/100 g b.w.). Blood and liver samples were collected 12 h, 24 h, 48 h and 7 days after intoxication. Blood morphology, liver function blood tests, histopathological changes, proliferation activity, apoptosis, fibrosis, and gene expression were analysed to assess liver damage. At 12 h, 24 h, and 48 h after CCl4 injection, mouse livers showed moderate inflammatory infiltration and massive pericentral necrosis. In rats treated with CCl4, minor lymphocytic infiltration in the liver parenchyma was seen at 12 h, followed by necrosis that appeared around central veins at 24 h and persisted to 48 h. In D-GalN-injected mice, the first histopathological signs of liver injury appeared at 48 h. In the livers of D-GalN-treated rats, moderate pericentral inflammatory infiltration occurred after 12 h, 24 h, and 48 h, accompanied by increased proliferation and apoptosis. All histological changes were accompanied by decreasing expression of certain genes. In most experimental groups of rats and mice, both histological and molecular parameters returned to the baseline values between 48 h and 7 days after intoxication. In mice and rats with CCl4-induced ALF, signs of liver failure can be seen as early as 12 h and develop to 48 h. In the D-GalN-induced model, mice are more resistant to the hepatotoxic effect than rats (after 12 h), and the early hepatitis phase can be observed much later, after 48 h. These cut-off points seem to be optimal for suppressing inflammation and applying effective stem cell therapy for acute liver injury.

The Key Molecular Mechanisms of Sini Decoction Plus Ginseng Soup to Rescue Acute Liver Failure: Regulating PPARα to Reduce Hepatocyte Necroptosis?

PurposeThis study aimed to investigate the improvement effect of Sini Decoction plus Ginseng Soup (SNRS) on the LPS/D-GalN-induced acute liver failure (ALF) mouse model and the molecular mechanism of the SNRS effect.MethodsTo study the protective effect of SNRS on ALF mice, the ICR mice were firstly divided into 4 groups: Control group (vehicle-treated), Model group (LPS/D-GalN), SNRS group (LPS/D-GalN+SNRS), and Silymarin group (LPS/D-GalN+Silymarin), the therapeutic drug was administered by gavage 48h, 24h before, and 10 min after LPS/D-GalN injection. On this basis, the peroxisome proliferator-activated receptor (PPAR) α agonist (WY14643) and inhibitor (GW6471) were added to verify whether the therapeutic mechanism of SNRS is related to its promoting effect on PPARα. The animals are grouped as follows: Control group (vehicle-treated), Model group (LPS/D-GalN+DMSO), SNRS group (LPS/D-GalN+SNRS+DMSO), Inhibitor group (LPS/D-GalN+GW6471), Agonist group (LPS/D-GalN+WY14643), and Inhibitor+SNRS group (LPS/D-GalN+GW6471+SNRS).ResultsThe protective effect of SNRS on the ALF model is mainly reflected in the reduction of serum alanine aminotransaminase (ALT) and aspartate aminotransaminase (AST) as well as the ameliorated pathology of the liver tissue. The survival rate of ALF mice treated with SNRS was significantly increased. Further mechanism studies showed that SNRS significantly promoted the protein expression of PPARα and decreased the expression of necroptosis proteins (RIP3, MLKL, p-MLKL) in ALF mice. Reduced necroptosis resulted in decreased HMGB1 release, which in turn inhibited the activation of TLR4-JNK and NLRP3 inflammasome signaling pathways and the expression of NF-κB protein induced by LPS/D-GalN. The expression of CPT1A, a key enzyme involved in fatty acid β-oxidation, was found to be significantly up-regulated in the SNRS treated group, accompanied by an increased adenosine-triphosphate (ATP) level, which may be the relevant mechanism by which SNRS reduces necroptosis.ConclusionThe potential therapeutic effect of SNRS on ALF may be through promoting the expression of PPARα and increasing the level of ATP in liver tissue, thereby inhibiting necroptosis of hepatocytes, reducing hepatocyte damage, and improving liver function.

Alanine Aminotransferase and Bilirubin Dynamic Evolution Pattern as a Novel Model for the Prediction of Acute Liver Failure in Drug-Induced Liver Injury.

Aims: To develop, optimize, and validate a novel model using alanine aminotransferase (ALT) and total bilirubin (TB) dynamic evolution patterns in predicting acute liver failure (ALF) in drug-induced liver injury (DILI) patients. Methods: The demographics, clinical data, liver biopsy, and outcomes of DILI patients were collected from two hospitals. According to the dynamic evolution of ALT and TB after DILI onset, the enrolled patients were divided into ALT-mono-peak, TB-mono-peak, double-overlap-peak, and double-separate-peak (DSP) patterns and compared. Logistic regression was used to develop this predictive model in both discovery and validation cohorts. Results: The proportion of ALF was significantly higher in patients with the DSP pattern than in the ALT-mono-peak pattern and DOP pattern (10.0 vs. 0.0% vs. 1.8%,p < 0.05). The area under receiver operating characteristic curve (AUROC) of the DSP pattern model was 0.720 (95% CI: 0.682–0.756) in the discovery cohort and 0.828 (95% CI: 0.788–0.864) in the validation cohort in predicting ALF, being further improved by combining with international normalized ratio (INR) and alkaline phosphatase (ALP) (AUROC in the discovery cohort: 0.899; validation cohort: 0.958). Histopathologically, patients with the DSP pattern exhibited a predominantly cholestatic hepatitis pattern (75.0%, p < 0.05) with a higher degree of necrosis (29.2%, p = 0.084). Conclusion: DILI patients with the DSP pattern are more likely to progress to ALF. The predictive potency of the model for ALF can be improved by incorporating INR and ALP. This novel model allows for better identification of high-risk DILI patients, enabling timely measures to be instituted for better outcome.

SIRT3 inhibitor 3-TYP exacerbates thioacetamide-induced hepatic injury in mice.

The purpose of the study was to explore the effects of SIRT3 inhibitor 3-TYP on acute liver failure (ALF) in mice and its underlying mechanism. The mice were treated with thioacetamide (TAA, 300 mg/kg) for inducing ALF model. 3-TYP (50 mg/kg) was administered 2 h prior to TAA. The liver histological changes were measured by HE staining. Blood samples were collected for analysis of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). MDA and GSH were used to evaluate the oxidative stress of liver. The expression levels of inflammatory cytokines (TNF-α and IL-1β) were measured by ELISA and Western blotting. The cell type expression of IL-1β in liver tissue was detected by immunofluorescent staining. The expression of SIRT3, MnSOD, ALDH2, MAPK, NF-κB, Nrf2/HO-1, p-elF2α/CHOP, and cleaved caspase 3 was determined by Western blotting. TUNEL staining was performed to detect the apoptosis cells of liver tissues. 3-TYP exacerbated the liver injury of ALF mice. 3-TYP increased the inflammatory responses and activation of MAPK and NF-κB pathways. In addition, 3-TYP administration enhanced the damage of oxidative stress, endoplasmic reticulum stress, and promoted hepatocyte apoptosis in ALF mice. 3-TYP exacerbates thioacetamide-induced hepatic injury in mice. Activation of SIRT3 could be a promising target for the treatment of ALF.

Mesenchymal stem cells derived from different perinatal tissues donated by same donors manifest variant performance on the acute liver failure model in mouse

BackgroundMesenchymal stem cells (MSCs) derived from different tissues have variant biological characteristics, which may induce different performances in the treatment of diseases. At present, it is difficult to know which type of MSC is most suitable for acute liver failure (ALF), and there is no parallel study to compare MSCs from different tissues of the same donor.MethodsIn this study, we derived MSCs from three different perinatal tissues of the same donor: cord lining (CL), cord–placenta junction (CPJ) and fetal placenta (FP), respectively, for compared gene expression profiles by transcriptome sequencing, and ability of proliferation and immune regulation in vitro. In addition, the therapeutic effects (e.g., survival rate, histological evaluation, biochemical analysis) of CL-MSCs, FP-MSCs and CPJ-MSCs on ALF mouse model were compared.ResultsThe transcriptome analysis showed that FP-MSCs have significantly high expression of chemokines compared to CPJ-MSCs and CL-MSCs, similar to the q-PCR result. Of note, we found that CPJ-MSCs and FP-MSCs could improve the survival rate of mice with ALF induced by carbon tetrachloride, but CL-MSCs had no difference with Sham group. Moreover, we also found that biomarkers of ALF (e.g., MDA, SOD and GSH-px) significantly improved post-CPJ-MSCs and FP-MSCs treatment, but not CL-MSCs and Sham group. However, CL-MSCs treatment leads to inflammatory reaction in the early stage (day 3) of ALF treatment but not found with other groups.ConclusionsIt is important to select the MSCs derived from different tissues with variant performance for therapeutic purpose, and the CPJ-MSCs and FP-MSCs cells can significantly improve the syndrome of ALF which is highly recommended for a potential therapeutic options for ALF.

Buddleoside inhibits TLR4-related pathway in a mouse model of acute liver failure, promotes autophagy, and inhibits inflammation

Purpose: To study the inhibitory influence of buddleoside on TLR4-associated pathway, autophagy and inflammation in a mouse model of acute liver failure (ALF).Methods: Sixty male C57BL/6 mice were assigned to 5 groups: control, model, and three dose-groups of buddleoside, with 12 mice per group. Levels of interleukin (IL)-1, IL-6, TLR4 pathway-associated proteins, and autophagy-related proteins in each group were determined; cell adhesion in each group was also analyzed.Results: Levels of TLR4, MAPK and NF-кB-related pathways in model mice were significantly upregulated, relative to control mice, but they were more down-regulated in the 3 anthocyanin groups than in model group (p &lt; 0.05). There were significantly higher levels of TNF-α, IL- and IL-6 in model mice than in the control group, but they were down-regulated in high-, medium- and low-dose mice, relative to model mice. The population of adherent cells was significantly higher in ALF mice than in controls, butthere were markedly lower numbers of these cells in the 3 anthocyanin-treated mice than in model mice (p &lt; 0.05).Conclusion: Buddleoside mitigates ALF in mice by down-regulating inflammatory factors, reducing serum levels of ALT and AST, and up-regulating autophagy-related protein expressions by activating TLR4/MAPK/NF-кB signaling pathway. Thus, buddleoside may be useful in the treatment of acute liver failure, but this has to be curtained through clinical trials.

Characterization of Hepatic Injury During the Azoxymethane Model of Acute Liver Failure

IntroductionAcute liver failure (ALF) results from a significant loss of liver function and has few effective treatments and poor clinical outcomes. ALF is associated with neurological dysfunction, called type A hepatic encephalopathy (HE), which greatly increases mortality. One of the commonly used models of type A HE is the azoxymethane (AOM) mouse model, which is associated with hepatocyte necrosis, neuroinflammation and oxidative stress. That being said, there have been no extensive analyses into the hepatic pathology associated with AOM‐induced liver injury. Therefore, the aim of this study was to characterize the hepatic injury during the AOM model of type A HE.MethodsC57Bl/6 mice were administered 100 mg/kg of AOM and were euthanized at various stages of neurological decline and tissue was collected. These stages include normal (vehicle‐treated), prior to neurological decline (pre), minor neurological decline (minor), significant neurological decline (major), and coma. Liver injury was assessed by measuring serum ALT and AST levels as well as liver H&amp;E staining. Serum albumin, bile acids, glutathione (GSH) and ammonia were measured to determine liver function. Various aspects of oxidative stress, inflammation and cell death were assessed by measuring CYP2E1, Nrf2, SOD1, CCL2, IL‐1β, IL‐6, LC3‐II, phosphorylated MLKL, cleaved caspase 3, p21 and TGFβ1 expression using real‐time PCR, immunoblotting, ELISA or immunohistochemistry. All data were analyzed using GraphPad Prism software with results presented as mean +/‐ SEM. Differences between two groups were compared using the Student’s t‐test and differences between three groups were determined using ANOVA.ResultsAOM‐treated mice had significant elevations of serum ALT and AST and hepatic necrosis as neurological decline progressed. CYP2E1 expression decreased throughout the stages of neurological decline, with the greatest suppression in mice at coma. Measures of oxidative stress and signaling had the largest increase when mice were at major neurological decline, which was also associated with the largest increase of inflammatory chemokines and cytokines. Measures of necroptosis, apoptosis and cellular senescence were also dysregulated, with coma mice showing the highest degrees of cell death and increased cellular senescence.ConclusionsThese data demonstrate that AOM‐treated mice have increased oxidative stress and inflammation resulting from the metabolic dysregulation from AOM toxicity. This leads to cell death through multiple different mechanisms and an impairment of regeneration due to increased cellular senescence.

SIRT6 Activator UBCS039 Inhibits Thioacetamide-Induced Hepatic Injury In Vitro and In Vivo.

SIRT6 has been reported to have multiple functions in inflammation and metabolism. In the present study, we explored the regulatory effects and mechanisms of SIRT6 in thioacetamide (TAA)-induced mice acute liver failure (ALF) models. The SIRT6 activator UBCS039 was used in this animal and cell experiments. We observed that UBCS039 ameliorated liver damage, including inflammatory responses and oxidative stress. Further study of mechanisms showed that the upregulation of SIRT6 inhibited the inflammation reaction by suppressing the nuclear factor-κB (NF-κB) pathway in the TAA-induced ALF mice model and lipopolysaccharide-stimulated macrophages. In addition, the upregulation of SIRT6 alleviated oxidative stress damage in hepatocytes by regulating the Nrf2/HO-1 pathway. These findings demonstrate that pharmacologic activator of SIRT6 could be a promising target for ALF.

Development of a prognostic model for pediatric acute liver failure in a Brazilian center

ObjectivePediatric acute liver failure (PALF) is a heterogeneous, rare, and severe condition, which outcome is survival due to liver spontaneous recovery or death. The patients who do not recover may be allocated to liver transplantation, which is the standard treatment. This study aimed to build a prognostic model to support the clinical decision to indicate liver transplantation for patients with PALF in a Brazilian center. MethodsThe authors retrospectively analyzed the clinical variables of 120 patients in the liver transplantation program of the 'Children's Institute of the University of São Paulo, Brazil. The authors conducted a univariate analysis of variables associated with survival in PALF. Logistic multivariate analysis was performed to find a prognostic model for the outcome of patients with pediatric acute liver failure. ResultsRisk factors were analyzed using univariate analysis. Two prognostic models were built using multiple logistic regression, which resulted in 2 models: model 1(INR/ALT) and model 2 (INR/Total bilirubin). Both models showed a high sensitivity (97.9%/96.9%), good positive predictive value (89.5%/90.4%), and accuracy (88.4%/88.5%), respectively. The receiver operating characteristic was calculated for both models, and the area under the curve was 0.87 for model 1 and 0.88 for model 2. The Hosmer-Lemeshow test showed that model 1 was good. ConclusionThe authors built a prognostic model for PALF using INR and ALT that can contribute to the clinical decision to allocate patients to liver transplantation.

Morphology of Acute Liver Failure During Treatment With a Combination of Drug Therapy and Transplanted Cultured Hepatocytes.

We analyzed liver tissue morphology dynamics in experimental animals with acute liver failure during treatment with a combination of transplanted cultured embryonic hepatocytes and the hepatoprotective drug Erbisol. We studied 30 white outbred male rats weighing 250 to 350 g, divided into 6 groups with 5 animals in each group. Acute liver damage was induced by a hepatotoxic model of acute liver failure for which carbon tetrachloride was applied (200 μg CCl4/100 g body weight with toxin-to-oil volume ratio of 1:1). To obtain cultured embryonic hepatocytes, we used an enzymatic-mechanical process that caused only minimal cell damage. This method is known to improve the output of viable cultured embryonic hepatocytes, improve the morphological-functional properties of the hepatocytes, and reduce the process time during procurement, and thereby reduce the overall time from procurement to the subsequent culturing of the obtained cells. Transplant of cultured embryonic hepatocytes was performed intrape-ritoneally at a dose of 50 million (0.5 × 108) cells. Morphological studies were performed on day 7 and day 21 of the experiment. There were significant morphological changes in livers from animals with acute liver failure, caused by widespread necrosis and an elevated inflammatory response. Treatment with injections of cultured embryonic hepatocytes induced regeneration of the liver parenchyma cells and reduced the inflammatory response, both of which were further reduced in rats that received combined treatment of transplant with Erbisol. Combined application of cultured embryonic hepatocytes and Erbisol potentiated the effects of both treatments, which produced intensive proliferation of hepatocytes, hypertrophy and polyploidization of hepatocyte nuclei, and an early restoration of liver structure and organ mass.

Animal models applied to acute-on-chronic liver failure: Are new models required to understand the human condition?

The liver is a multifaceted organ; its location and detoxifying function expose this organ to countless injuries. Acute-on-chronic failure liver (ACLF) is a severe syndrome that affects the liver due to acute decompensation in patients with chronic liver disease. An infection environment, ascites, increased liver enzymes and prothrombin time, encephalopathy and fast-evolving multiorgan failure, leading to death, usually accompany this. The pathophysiology remains poorly understand. In this context, animal models become a very useful tool in this regard, as understanding; the disease may be helpful in developing novel therapeutic methodologies for ACLF. However, although animal models display several similarities to the human condition, they do not represent all ACLF manifestations, resulting in significant challenges. An initial liver cirrhosis framework followed by the induction of an acute decompensation by administering lipopolysaccharide and D-GaIN, potentiating liver damage supports the methodologies applied to induce experimental ACLF. The entire methodology has been described mostly for rats. Nevertheless, a quick PubMed database search indicates about 30 studies concerning ACFL models and over 1000 regarding acute liver failure models. These findings demonstrate the clear need to establish easily reproducible ACFL models to elucidate questions about this quickly established and often fatal syndrome.

3,4-dihydroxyphenylethyl alcohol glycoside reduces acetaminophen-induced acute liver failure in mice by inhibiting hepatocyte ferroptosis and pyroptosis.

APAP is one of the most commonly used antipyretic and pain medications, but excessive use can cause liver toxicity and damage. 3,4-dihydroxyphenylethyl alcohol glycoside (DAG) is a component isolated from Sargentodoxa cuneata known to have anti-apoptotic, anti-oxidation and anti-inflammatory effects. However, the effects of DAG on acute liver failure (ALF) are largely unknown. The purpose of this study is to study the protective effects and mechanism of DAG on APAP-induced ALF in mice. We established an ALF model in adult male pathogen-free C57BL/6 mice treated with APAP (300 mg/kg) by intraperitoneal injection and resolved by 24 h. Hematoxylin and eosin (HE) staining was used to evaluate the pathological changes in mouse liver tissue. The infiltration of neutrophils in liver tissue and reactive oxygen species (ROS) in AML12 cells were analyzed by flow cytometry. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutathione (GSH), malondialdehyde (MDA), catalase (CAT), and superoxide dismutase (SOD) were analyzed using relevant kits. Our results show that DAG reduced APAP-induced serum ALT and AST levels, histopathological changes, liver neutrophil infiltration and proinflammatory cytokines production, also attenuated the accumulation of MDA and the exhaustion of GSH, CAT and SOD. In vitro experiment indicated that DAG dose-dependently inhibited APAP-induced the levels of pro-inflammatory factors (IL-1β and IL18), and reactive oxygen species (ROS) and preventing GSH depletion in mouse AML12 hepatocytes. More interestingly, DAG inhibited the expression of ERK, HO-1, NLRP3, Caspase1 (p20) and Gasdermin-D and upregulated the expression of GPX4 in liver tissues and AML12hepatocytes. Therefore, our results indicate that DAG may act as a potential agent to treat ALF induced by APAP by inhibiting hepatocyte ferroptosis and pyroptosis.

Gasdermin D Inhibitor Necrosulfonamide Alleviates Lipopolysaccharide/D-galactosamine-induced Acute Liver Failure in Mice.

Acute liver failure (ALF) is associated with high mortality. Gasdermin D (GSDMD) is the executioner of pyroptosis and is involved in the pathophysiology of immune dysregulation This study investigated the role of the GSDMD inhibitor necrosulfonamide (NSA) in ALF. An ALF model was established by lipopolysaccharide/D-galactosamine challenge in C57BL/6J mice. Mice were divided into four groups: normal controls (control group), ALF group (ALF group), dimethyl sulfoxide group (DMSO group), and NSA intervention group (NSA group). Survival was monitored, liver damage was determined by hematoxylin and eosin staining, and serum alanine aminotransferase (ALT). Underlying mechanisms were explored by quantitative real-time PCR, western blotting, and enzyme-linked immunosorbent assays. Pyroptosis was activated in ALF model mice. Mice treated with GSDMD inhibitor NSA developed less severe liver failure. NSA reduced the expression of GSDMD, NLRP3, cleaved caspase-1, cleaved caspase-11, and secretion of interleukin-1 beta in ALF mice model. Pyroptosis was activated in ALF. NSA alleviated ALF via the pyroptosis pathway.

The Interplay between Autophagy and Virus Pathogenesis-The Significance of Autophagy in Viral Hepatitis and Viral Hemorrhagic Fevers.

Autophagy is a process focused on maintaining the homeostasis of organisms; nevertheless, the role of this process has also been widely documented in viral infections. Thus, xenophagy is a selective form of autophagy targeting viruses. However, the relation between autophagy and viruses is ambiguous—this process may be used as a strategy to fight with a virus, but is also in favor of the virus’s replication. In this paper, we have gathered data on autophagy in viral hepatitis and viral hemorrhagic fevers and the relations impacting its viral pathogenesis. Thus, autophagy is a potential therapeutic target, but research is needed to fully understand the mechanisms by which the virus interacts with the autophagic machinery. These studies must be performed in specific research models other than the natural host for many reasons. In this paper, we also indicate Lagovirus europaeus virus as a potentially good research model for acute liver failure and viral hemorrhagic disease.

Amygdalin protects against acetaminophen-induced acute liver failure by reducing inflammatory response and inhibiting hepatocyte death

Amygdalin is a natural compound from Bitter Apricot Seed which is reported to have anti-inflammatory activity. Acetaminophen (APAP) resulted in drug-induced liver injury is the main cause of acute liver failure (ALI) worldwide and only N-acetylcysteine is the accepted detoxification drug. However, there is no effective medicine to perfect the hepatocyte death and secondary inflammation injury. In this study, we aim to investigate the protective effect of Amygdalin in the APAP-induced acute liver failure mice model. We establish the ALI model via intraperitoneal APAP injection and mice were treated with Amygdalin with intraperitoneal injection. We detected liver enzyme and histological change to evaluate the liver injury. We measured oxidative damage markers and inflammatory cell infiltration of liver tissues. At last, we investigated the mechanism of Amygdalin on protecting hepatocytes. Results showed that Amygdalin reduced ALT/AST level and decreased necrotic area of liver tissue. In addition, Amygdalin reduced the count of MPO+(neutrophils) and F4/80+(macrophages) of the liver and inhibited IL-6, TNF-a, and IL-1b expression. Amygdalin reduced liver SOD and MDA levels and increased Nrf2/NQO1/HO1 protein expression. Moreover, Amygdalin reduced TUNEL+ and P-MLKL + staining cells in liver tissue. Mechanically, Amygdalin promoted phosphorylation of AKT and suppressed JNK/RIP3/MLKL signaling.

Noncanonical Wnt5a/JNK Signaling Contributes to the Development of D-Gal/LPS-Induced Acute Liver Failure.

Acute liver failure (ALF) is a deadly clinical disorder with few effective treatments and unclear pathogenesis. In our previous study, we demonstrated that aberrant Wnt5a expression was involved in acute-on-chronic liver failure. However, the role of Wnt5a in ALF is unknown. We investigated the expression of Wnt5a and its downstream c-Jun N-terminal kinase (JNK) signaling in a mouse model of ALF established by coinjection of D-galactosamine (D-Gal) and lipopolysaccharide (LPS) in C57BL/6 mice. We also investigated the role of Box5, a Wnt5a antagonist, in vivo. Moreover, the effect of Wnt5a/JNK signaling on downstream inflammatory cytokine expression, phagocytosis, and migration in THP-1 macrophages was studied in vitro. Aberrant Wnt5a expression and JNK activation were detected in D-Gal/LPS-induced ALF mice. Box5 pretreatment reversed JNK activation and eventually decreased the mortality rate of D-Gal/LPS-treated mice, with reduced hepatic necrosis and apoptosis, serum ALT and AST levels, and liver inflammatory cytokine expression, although the latter was not significant. We further demonstrated that recombinant Wnt5a (rWnt5a)-induced tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) mRNA expression and increased THP-1 macrophage phagocytosis in a JNK-dependent manner, which could be restored by Box5. In addition, rWnt5a-induced migration of THP-1 macrophages was also reversed by Box5. Our findings suggested that Wnt5a/JNK signaling plays an important role in the development of ALF and that Box5 could have particular hepatoprotective effects in ALF.