The Pathology of Acute Liver Failure

Inflammatory Bowel Disease Therapies and Acute Liver Injury

Drug-induced liver disease (DILI) represents one of the main problems in the therapeutic field. There are several non-modifiable risk factors, such as age and sex, and all drugs can cause hepatotoxicity of varying degrees, including those for the treatment of inflammatory bowel diseases (IBD). The aim of this review is to illustrate the adverse effects on the liver of the various drugs used in the treatment of IBD, highlighting which drugs are safest to use based on current knowledge. The mechanism by which drugs cause hepatotoxicity is not fully understood. A possible cause is represented by the formation of toxic metabolites, which in some patients may be increased due to alterations in the enzymatic apparatus involved in drug metabolism. Various studies have shown that the drugs that can most frequently cause hepatotoxicity are immunosuppressants, while mesalazine and biological drugs are, for the most part, less associated with such complications. Therefore, it is possible to assume that in the future, biological therapies could become the first line for the treatment of IBD.

Severe acute liver disease in adults: Contemporary role of histopathology

Liver biopsies have consistently contributed to our understanding of the pathogenesis and aetiologies of acute liver disease. As other diagnostic modalities have been developed and refined, the role of biopsy in the management of patients with acute liver failure (ALF), acute-on-chronic liver failure (ACLF) and acute hepatitis, including acute liver injury (ALI), has changed. Liver biopsy remains particularly valuable when first-line diagnostic algorithms fail to determine aetiology. Despite not being identified as a mandatory diagnostic tool in recent clinical guidelines for the management of ALF or ACLF, many centres continue to undertake biopsies given the relative safety of transjugular biopsy in this setting. Several studies have demonstrated that liver biopsy can provide prognostic information, particularly in the context of so-called indeterminate hepatitis, and is extremely useful in excluding conditions such as metastatic tumours that would preclude transplantation. In addition, its widespread use of percutaneous biopsies in cases of less severe acute liver injury, for example in the establishment of a diagnosis of acute presentation of autoimmune hepatitis or confirmation of a probable or definite drug-induced liver injury (DILI), has meant that many centres have seen a shift in the ratio of specimens they are receiving from patients with chronic to acute liver disease. Histopathologists therefore need to be equipped to deal with these challenging specimens. This overview provides an insight into the contemporary role of biopsies (as well as explant and autopsy material) in diagnosing acute liver disease. It outlines up-to-date clinical definitions of liver injury and considers recent recommendations for the diagnosis of AIH and drug-induced, autoimmune-like hepatitis (DI-AIH).

Treatment with β-Adrenoceptor Agonist Isoproterenol Reduces Non-parenchymal Cell Responses in LPS/D-GalN-Induced Liver Injury

There is an increasing evidence indicating the involvement of the sympathetic nervous system (SNS) in liver disease development. To achieve an extensive comprehension of the obscure process by which the SNS alleviates inflammatory damage in non-parenchymal liver cells (NPCs) during acute liver failure (ALF), we employ isoproterenol (ISO), a beta-adrenoceptor agonist, to mimic SNS signaling. ISO was administered to C57BL/6J mice to establish an acute liver failure (ALF) model using LPS/D-GalN, which was defined as ISO + ALF. Non-parenchymal cells (NPCs) were isolated from liver tissues and digested for tandem mass tag (TMT) labeled proteomics to identify differentially expressed proteins (DEPs). The administration of ISO resulted in a decreased serum levels of pro-inflammatory cytokines, e.g., TNF-α, IL-1β, and IL-6 in ALF mice, which alleviated liver damage. By using TMT analysis, it was possible to identify 1587 differentially expressed proteins (DEPs) in isolated NPCs. Notably, over 60% of the DEPs in the ISO + ALF vs. ALF comparison were shared in the Con vs. ALF comparison. According to enrichment analysis, the DEPs influenced by ISO in ALF mice were linked to biological functions of heme and fatty acid metabolism, interferon gamma response, TNFA signaling pathway, and mitochondrial oxidation function. Protein-protein interaction network analysis indicated Mapk14 and Caspase3 may serve as potentially valuable indicators of ISO intervention. In addition, the markers on activated macrophages, such as Mapk14, Casp1, Casp8, and Mrc1, were identified downregulated after ISO initiation. ISO treatment increased the abundance of anti-inflammatory markers in mouse macrophages, as evidenced by the immunohistochemistry (IHC) slides showing an increase in Arg + staining and a reduction in iNOS + staining. Furthermore, pretreatment with ISO also resulted in a reduction of LPS-stimulated inflammation signaling markers, Mapk14 and NF-κB, in human THP-1 cells. Prior treatment with ISO may have the potential to modify the biological functions of NPCs and could serve as an innovative pharmacotherapy for delaying the pathogenesis and progression of ALF.

Drug induced liver injury - a 2023 update

Drug-Induced Liver Injury (DILI) constitutes hepatic damage attributed to drug exposure. DILI may be categorized as hepatocellular, cholestatic or mixed and might also involve immune responses. When DILI occurs in dose-dependent manner, it is referred to as intrinsic, while if the injury occurs spontaneously, it is termed as idiosyncratic. This review predominately focused on idiosyncratic liver injury. The established molecular mechanisms for DILI include (1) mitochondria dysfunction, (2) increased reactive oxygen species levels, (3) presence of elevated apoptosis and necrosis, (4) and bile duct injuries associated with immune mediated pathways. However, it should be emphasized that the underlying mechanisms responsible for DILI are still unknown. Prevention strategies are critical as incidences occur frequently, and treatment options are limited once the injury has developed. The aim of this review was to utilize retrospective cohort studies from across the globe to gain insight into epidemiological patterns. This review considers (1) what is currently known regarding the mechanisms underlying DILI, (2) discusses potential risk factors and (3) implications of the coronavirus pandemic on DILI presentation and research. Future perspectives are also considered and discussed and include potential new biomarkers, causality assessment and reporting methods.

Combined Age with Mean Decrease Rates of Total Bilirubin and MELD Score as a Novel and Simple Clinical Predictor on 90-Day Transplant-Free Mortality in Adult Patients with Acute Liver Failure Undergoing Plasma Exchange: A Single-Center Retrospective Study

Background

Acute liver failure (ALF), previously known as fulminant hepatic failure, has become a common, rapidly progressive, and life-threatening catastrophic hepatic disease in intensive care unit (ICU) due to the continuous increase in drug abuse, viral infection, metabolic insult, and auto-immune cause. At present, plasma exchange (PE) is the main effective alternative treatment for ALF in ICU clinical practice, and high-volume plasma exchange (HVP) has been listed as a grade I recommendation for ALF management in the American Society for Apheresis (ASFA) guidelines. However, no existing models can provide a satisfactory performance for clinical prediction on 90-day transplant-free mortality in adult patients with ALF undergoing PE. Our study aims to identify a novel and simple clinical predictor of 90-day transplant-free mortality in adult patients with ALF undergoing PE.

Methods

This retrospective study contained adult patients with ALF undergoing PE from the Medical ICU (MICU) in the Second Affiliated Hospital of Harbin Medical University between January 2017 and December 2020. Baseline and clinical data were collected and calculated on admission to ICU before PE, including gender, age, height, weight, body mass index (BMI), etiology, total bilirubin, direct bilirubin, indirect bilirubin, prothrombin activity, model for end-stage liver disease (MELD) score, and sequential organ failure assessment (SOFA) score. Enrolled adult patients with ALF undergoing PE were divided into a survival group and a death group at discharge and 90 days on account of medical records and telephone follow-up. After each PE, decreased rates of total bilirubin and MELD score and increased rates of prothrombin activity were calculated according to the clinical parameters. In clinical practice, different patients underwent different times of PE, and thus, mean decrease rates of total bilirubin and MELD score and mean increase rate of prothrombin activity were obtained for further statistical analysis.

Results

A total of 73 adult patients with ALF undergoing 204 PE were included in our retrospective study, and their transplant-free mortality at discharge and 90 days was 6.85% (5/73) and 31.51% (23/73), respectively. All deaths could be attributed to ALF-induced severe and life-threatening complications or even multiple organ dysfunction syndrome (MODS). Most of the enrolled adult patients with ALF were men (76.71%, 56/73), with a median age of 48.77 years. Various hepatitis virus infections, unknown etiology, auto-immune liver disease, drug-induced liver injury, and acute pancreatitis (AP) accounted for 75.34%, 12.33%, 6.85%, 4.11%, and 1.37% of the etiologies in adult patients with ALF, respectively. Univariate analysis showed a significant difference in age, mean decrease rates of total bilirubin and MELD score mean increase rate of prothrombin activity, decrease rates of total bilirubin and MELD score, and increase rate of prothrombin activity after the first PE between the death group and survival group. Multivariate analysis showed that age and mean decrease rates of total bilirubin and MELD score were closely associated with 90-day transplant-free mortality in adult patients with ALF undergoing PE. The 90-day transplant-free mortality was 1.081, 0.908, and 0.893 times of the original value with each one-unit increase in age and mean decrease rates of total bilirubin and MELD score, respectively. The areas under the receiver operatingcharacteristic (ROC) curve of age, mean decrease rates of total bilirubin and MELD score, and the three combined were 0.689, 0.225, 0.123, and 0.912, respectively. The cut-off values of age, mean decrease rates of total bilirubin and MELD score, and the three combined were 61.50, 3.12, 1.21, and 0.33, respectively. The specificity and sensitivity of combined age with mean decrease rates of total bilirubin and MELD score for predicting 90-day transplant-free mortality in adult patients with ALF undergoing PE were 87% and 14%.

Conclusion

Combined age with mean decrease rates of total bilirubin and MELD score as a novel and simple clinical predictor can accurately predict 90-day transplant-free mortality in adult patients with ALF undergoing PE, which is worthy of application and promotion in clinical practice, especially in the identification of potential transplant candidates.

Pathology of Acute and Acute-on-Chronic Liver Failure

Liver failure can develop as either acute liver failure in the absence of preexisting liver disease, or as acute-on-chronic liver failure in a patient with underlying chronic liver disease or cirrhosis. A timely liver biopsy is helpful to distinguish acute and chronic liver disease, identify precipitating factors, provide prognostic information based on pathologic changes, and aid in making appropriate decisions for patient management. This article will discuss the pathologic features of acute and acute-on-chronic liver failure. Developing an appreciation for the histopathologic patterns of injury observed in these entities is essential for a practical understanding of the diagnostic process.

Calycosin inhibits hepatocyte apoptosis in acute liver failure by suppressing the TLR4/NF-κB pathway: An in vitro study

BACKGROUND

Acute liver failure (ALF) is a serious liver disease that is difficult to treat owing to its unclear pathogenesis. This study aimed to investigate the roles and molecular mechanisms of calycosin (CA) in ALF.

METHODS

In this study, the roles and mechanism of CA in ALF were explored using an in vitro lipopolysaccharide (LPS)-induced ALF cell model. Additionally, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide assay was used to assess the effect of CA on the activity of LPS-induced L02 human liver epithelial cells, and flow cytometry was used to detect apoptosis in L02 cells. Expression levels of apoptosis-related genes, Bax and Bcl-2, were measured using reverse transcription-quantitative polymerase chain reaction and Western blot analysis. Expression levels of inflammatory factors in LPS-induced L02 cells were measured using an enzyme-linked immunosorbent assay. Additionally, the effect of CA on ALF was inhibited via transfection of a toll-like receptor 4 (TLR4)-plasmid to elucidate the relationship between CA and TLR4/nuclear factor (NF)-κB signaling pathway in ALF.

RESULTS

CA had no toxic effects on L02 cells, but enhanced the activity of LPS-induced L02 cells in a dose-dependent manner. Apoptosis and inflammatory factor release was increased in ALF, activating the TLR4/NF-κB signaling pathway. However, CA treatment inhibited the apoptosis and release of inflammatory factors. Further mechanistic studies revealed that the upregulation of TLR4 expression reversed the alleviating effects of CA on inflammation and apoptosis in LPS-induced L02 cells.

CONCLUSION

CA alleviates inflammatory damage in LPS-induced L02 cells by inhibiting the TLR4/NF-κB pathway and may be a promising therapeutic agent for ALF treatment.

Human embryonic stem cell-derived immunity-and-matrix regulatory cells promote intrahepatic cell renewal to rescue acute liver failure

Acute liver failure (ALF) is a clinical syndrome characterized by the accelerated development of hepatocyte necrosis and significant mortality. Given that liver transplantation is now the only curative treatment available for ALF, there is an urgent need to explore innovative therapies. Mesenchymal stem cells (MSCs) have been applied in preclinical studies for ALF. It had been demonstrated that human embryonic stem cell-derived immunity-and-matrix regulatory cells (IMRCs) met the properties of MSCs and had been employed in a wide range of conditions. In this study, we conducted a preclinical evaluation of IMRCs in the treatment of ALF and investigated the mechanism involved. ALF was induced in C57BL/6 mice via intraperitoneal administration of 50% CCl₄ (6 mL/kg) mixed with corn oil, followed by intravenous injection of IMRCs (3 × 10⁶ cells/each). IMRCs improved histopathological changes in the liver and reduced alanine transaminase (ALT) or aspartate transaminase (AST) levels in serum. IMRCs also promoted cell renewal in the liver and protected it from CCl₄ damage. Furthermore, our data indicated that IMRCs protected against CCl₄-induced ALF by regulating the IGFBP2-mTOR-PTEN signaling pathway, which is associated with the repopulation of intrahepatic cells. Overall, IMRCs offered protection against CCl₄-induced ALF and were capable of preventing apoptosis and necrosis in hepatocytes, which provided a new perspective for treating and improving the prognosis of ALF.

Inhibition of inflammatory liver injury by the HMGB1-A box through HMGB1/TLR-4/NF-κB signaling in an acute liver failure mouse model

We aimed to investigate the preventive effect of high mobility group box 1 (HMGB1)-A box and the mechanism by which it alleviates inflammatory injury in acute liver failure (ALF) by inhibiting the extracellular release of HMGB1. BALB/c mice were intraperitoneally (i.p.) administered LPS/D-GalN to establish an ALF mouse model. HMGB1-A box was administered (i.p.) 1 h before establishing the ALF mouse model. The levels of extracellularly released HMGB1, TLR-4/NF-κB signaling molecules, the proinflammatory cytokines TNF-α, IL-1β, and IL-6 and COX-2 were measured in the liver tissue and/or serum by Immunohistochemistry, Western blotting and Enzyme-linked immunosorbent assay (ELISA). The levels of extracellularly released HMGB1, TLR-4/NF-κB signaling molecules and proinflammatory cytokines were measured in Huh7 cells as well as LPS- and/or HMGB1-A box treatment by confocal microscopy, Western blotting and ELISA. In the ALF mouse model, the levels of HMGB1 were significantly increased both in the liver and serum, TLR-4/NF-κB signaling molecules and proinflammatory cytokines also was upregulated. Notably, HMGB1-A box could reverse these changes. HMGB1-A box could also cause these changes in LPS-induced Huh7 cells. HMGB1-A box played a protective role by inhibiting inflammatory liver injury via the regulation of HMGB1/TLR-4/NF-κB signaling in the LPS/D-GaIN-induced ALF mouse model, which may be related to inhibiting the extracellular release of HMGB1.

NOD2-mediated HDAC6/NF-κb signalling pathway regulates ferroptosis induced by extracellular histone H3 in acute liver failure

Acute liver failure (ALF) is life-threatening and often associated with high mortality rates. The aim of the present study was to investigate whether extracellular histone H3 could induce ferroptosis in hepatic macrophages in ALF and explore its potential mechanism. RAW264.7 macrophages and C57BL/6 mice were used in this study. LPS, D-galactosamine (D-Gal), histone H3, histone H3 antibody, NOD2 agonist Muramyl Dipeptide (MDP) and HDAC6-siRNA were administered in this study. The key molecules of ferroptosis, NOD2, HDAC6 and the NF-κb pathway, were detected. In vitro, histone H3 was released into the extracellular environment from cell nucleus after LPS exposure. In addition, histone H3 could induce ferroptosis in RAW264.7 macrophages with increased level of Fe²⁺ and ROS and decreased levels of GPX4 and GSH. MDP further aggravated ferroptosis in RAW264.7 macrophages stimulated by histone H3, which was accompanied by elevated NOD2, HDAC6, p-P65 and IκBα. HDAC6-siRNA ameliorated ferroptosis in RAW264.7 macrophages induced by histone H3, which was accompanied by decreased levels of HDAC6, p-P65 and IκBα. However, HDAC6-siRNA did not alter NOD2 levels in RAW264.7 macrophages administered histone H3. In vivo, the levels of NOD2, HDAC6 the NF-κb pathway and ferroptosis were increased in ALF mice, which were downregulated by histone H3 antibody and upregulated by histone H3. Extracellular histone H3 could induce ferroptosis in hepatic macrophages in ALF by regulating theNOD2-mediated HDAC6/NF-κb signalling pathway.

Prognostic Role of Liver Biopsy in Patients With Severe Indeterminate Acute Hepatitis

BACKGROUND AND AIMS

Severe indeterminate acute hepatitis (sIAH) is a poorly understood rare disease with no specific therapy. This study aims to define the clinicopathological characteristics of sIAH and the role of liver biopsy in determining prognosis.

METHODS

Patients with sIAH admitted to a single center between 2010 and 2019 were included. Histopathological patterns of liver biopsies were reviewed by 2 histopathologists, and key findings further were specified by multiplex immunofluorescence. Patients that died or underwent liver transplantation were analyzed as nonsurvivors.

RESULTS

Of 294 patients with acute hepatitis, 43 with sIAH were included. Seventeen (39.5%) underwent liver transplantation and 7 (16.2%) died within 3 months. Multilobular necrosis was the predominant histopathological feature, being significantly more frequent in nonsurvivors (62.5% vs 21.1%; P = .016). Necrotic areas showed low HNF4α and Ki67 expression but high expression of CK19 and cell death markers identifying areas of severe tissue injury and inadequate regenerative response. Patients with multilobular necrosis had higher international normalized ratio, Model for End-Stage Liver Disease, and Model for End-Stage Liver Disease-Sodium scores compared with those without (P values for all markers <.05). Multivariate Cox analysis revealed that multilobular necrosis (hazard ratio, 3.675; 95% confidence interval, 1.322-10.211) and lower body mass index (hazard ratio, 0.916; 95% confidence interval, 0.848-0.991) independently predicted death or transplantation.

CONCLUSIONS

The results of this study provide novel insights into the important role of liver biopsy in sIAH patients, suggesting that the presence of multilobular necrosis is an early indicator of poor prognosis.

Sensitive Activatable Nanoprobes for Real-Time Ratiometric Magnetic Resonance Imaging of Reactive Oxygen Species and Ameliorating Inflammation In Vivo

Imaging-guided real-time monitoring of the treatment process of inflammatory diseases is important for the timely adjustment of treatment planning to lower unnecessary side effects and improve treatment outcomes. However, it is difficult to reflect the dynamic changes of inflammation in vivo with enough tissue penetration depth. Here a novel nanotheranostic agent (denominated TMSN@PM) with platelet membrane (PM)-coated, tempol-grafted, manganese-doped, mesoporous silica nanoparticles is developed. The PM endows the TMSN@PM with the ability to target inflammation sites, which are verified by fluorescence imaging with Cyanine5 carboxylic acid (Cy5)-labeled TMSN@PM. Under the inflammatory environment (mild acidity and excess reactive oxygen species (ROS)), TMSN@PM can scavenge the excess ROS, thereby alleviating inflammation, degrade, and release manganese ions for enhanced magnetic resonance imaging (MRI). The relaxation changes (ΔR₁ ) are almost linearly correlated with the concentration of H₂ O₂ , which can reflect the degree of inflammation. This method offers a non-invasive imaging-based strategy for early prediction of the therapeutic outcomes in inflammatory therapy, which may contribute to precision medicine in terms of prognostic stratification and therapeutic planning in future.

Krill oil prevents lipopolysaccharide-evoked acute liver injury in mice through inhibition of oxidative stress and inflammation

Acute liver injury is a life-threatening syndrome that often results from the actions of viruses, drugs and toxins. Herein, the protective effect and potential mechanism of krill oil (KO), a novel natural product rich in long-chain n-3 polyunsaturated fatty acids bound to phospholipids and astaxanthin, on lipopolysaccharide (LPS)-evoked acute liver injury in mice were investigated. Male C57BL/6J mice were administered intragastrically with 400 mg kg^-1 KO or fish oil (FO) once per day for 28 consecutive days prior to LPS exposure (10 mg kg^-1, intraperitoneally injected). The results revealed that KO pretreatment significantly ameliorated LPS-evoked hepatic dysfunction indicated by reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and attenuated hepatic histopathological damage. KO pretreatment also mitigated LPS-induced hepatic oxidative stress, as evidenced by decreased malondialdehyde (MDA) contents, elevated glutathione (GSH) levels, and elevated catalase (CAT) and superoxide dismutase (SOD) activities. Additionally, LPS-evoked overproduction of pro-inflammatory mediators in serum and the liver was inhibited by KO pretreatment. Furthermore, KO pretreatment suppressed LPS-induced activation of the hepatic toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB)/NOD-like receptor family pyrin domain containing 3 (NLRP3) signaling pathway. Interestingly, the hepatoprotective effect of KO was superior to that of FO. Collectively, the current findings suggest that KO protects against LPS-evoked acute liver injury via inhibition of oxidative stress and inflammation.

Targeted Therapy for Inflammatory Diseases with Mesenchymal Stem Cells and Their Derived Exosomes: From Basic to Clinics

Inflammation is a beneficial and physiological process, but there are a number of inflammatory diseases which have detrimental effects on the body. In addition, the drugs used to treat inflammation have toxic side effects when used over a long period of time. Mesenchymal stem cells (MSCs) are pluripotent stem cells that can be isolated from a variety of tissues and can be differentiate into diverse cell types under appropriate conditions. They also exhibit noteworthy anti-inflammatory properties, providing new options for the treatment of inflammatory diseases. The therapeutic potential of MSCs is currently being investigated for various inflammatory diseases, such as kidney injury, lung injury, osteoarthritis (OA), rheumatoid arthritis (RA), and inflammatory bowel disease (IBD). MSCs can perform multiple functions, including immunomodulation, homing, and differentiation, to enable damaged tissues to form a balanced inflammatory and regenerative microenvironment under severe inflammatory conditions. In addition, accumulated evidence indicates that exosomes from extracellular vesicles of MSCs (MSC-Exos) play an extraordinary role, mainly by transferring their components to recipient cells. In this review, we summarize the mechanism and clinical trials of MSCs and MSC-Exos in various inflammatory diseases in detail, with a view to contributing to the treatment of MSCs and MSC-Exos in inflammatory diseases.

Fibroblast growth factor 9 attenuates sepsis-induced fulminant hepatitis in mice

Sepsis-induced fulminant hepatitis (FH) is a fatal syndrome that has a worse prognosis in clinical practice. Hence, seeking effective agents for sepsis-induced FH treatment is urgently needed. Fibroblast growth factors (FGFs) are vital for tissue homeostasis and damage repair in various organs including the liver. Our study aims to investigate the protective effects and potential mechanisms of FGF9 on lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced FH in mice. We found that pre-treatment with FGF9 exhibited remarkable hepaprotective effects on liver damage caused by LPS/D-Gal, as manifested by the concomitant decrease in mortality and serum aminotransferase activities, and the attenuation of hepatocellular apoptosis and hepatic histopathological abnormalities in LPS/D-Gal-intoxicated mice. We further found that FGF9 alleviated the infiltration of neutrophils into the liver, and decreased the serum levels of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in LPS/D-Gal-challenged mice. These effects can be explained at least in part by the inhibition of NF-κB signaling pathway. Meanwhile, FGF9 enhanced the antioxidative defense system in mice livers by upregulating the expression of NRF-2-related antioxidative enzymes, including glutamate-cysteine ligase catalytic subunit (GCLC), NAD(P)H: quinone oxidoreductase 1 (NQO-1), and heme oxygenase-1 (HO-1). These data indicate that FGF9 represents a promising therapeutic drug for ameliorating sepsis-induced FH via its anti-apoptotic and anti-inflammatory capacities.

Transjugular liver biopsy and hepatic venous pressure gradient measurement in patients with and without liver cirrhosis

BACKGROUND

Transjugular liver biopsy (TJLB) and hepatic venous pressure gradient (HVPG) measurement are diagnostic procedures for patients with acute and chronic liver diseases. Technical execution of TJLB and HVPG may be challenging in patients with advanced liver disease.

OBJECTIVE

We studied consecutive TJLB and HVPG procedures and investigated technical success, complications, quality of biopsies, indications and treatment changes in patients with and without liver cirrhosis.

METHODS

In the study period from 2010 to 2018, 575 consecutive TJLB and HVPG procedures were analyzed. Demographic characteristics, procedure-related and follow-up data were extracted from medical records.

RESULTS

In total, 259 (45%) patients were diagnosed with liver cirrhosis whereas 316 (55%) patients had no evidence of advanced chronic liver disease. Technical success of TJLB was significantly higher in patients without liver cirrhosis (287; 92%) compared to patients with liver cirrhosis [184; 76.7% (P = 0.001)]. Technical success of HVPG measurement was not different between both groups (P = 0.553). Liver biopsy specimens were significantly shorter in patients with liver cirrhosis (P = 0.001). Medical therapy was adjusted in 163 (28.4%) patients. In patients with liver cirrhosis, results of TJLB led less frequently to therapy initiation or adjustment compared to patients without liver cirrhosis (P = 0.001). In multivariate analysis, liver cirrhosis (Exp(B) 1.866; P = 0.012), alanine aminotransferase (Exp(B) 0.248; P < 0.001) and INR (Exp(B) 0.583; P = 0.027) were independently associated with treatment change.

CONCLUSION

Technical success and therapeutic decisions of TJLB are directly linked to presence or absence of liver cirrhosis.

[Histological features of paediatric acute liver failure : Experiences from a tertiary referral centre for paediatric liver disease in the UK]

Paediatric acute liver failure (PALF; also fulminant hepatic failure, fulminant hepatitis) is a critical clinical syndrome that is characterised by a sudden, rapid deterioration and disease progression in a usually previously healthy child. The pathogenesis is an advanced degree of hepatocellular necrosis that exceeds the rate of hepatocyte regeneration. The diagnostic criteria of PALF (modelled on adult criteria) were developed by the "Pediatric Acute Liver Failure (PALF) Study Group" (NIH). The rule of the liver biopsy in PALF is controversial and in some cases contraindicated (coagulopathic state). In addition, extensive necrosis is a common finding in PALFs but may not be predictive of the overall outcome (transplantation versus continuous treatment) due to sampling issues. There are, however, some histological patterns that offer a degree of specificity that can be carefully considered in the overall clinical picture. The histopathologists will be part of a multidisciplinary team and can contribute to the diagnostic and prognostic pathway.The aetiologies of PALF are numerous and depend on age and geographical region. For all age groups the main causes can be divided into infectious, immunological, metabolic and toxin drug related. Rarer causes include circulatory disorders and malignancies. In the paediatric group, up to 30-50% of causes leading to PALF remain unknown.

Preventive Effect of Flavonoid Extract from the Peel of Gonggan (Citrus reticulata Blanco Var. Gonggan) on CCl4-Induced Acute Liver Injury in Mice

Objective

Citrus peel, a waste product of citrus consumption and processing, is rich in flavonoids. This study aimed to study the protective effect of flavonoid extract from the peel of gonggan (Citrus reticulata Blanco var. gonggan) on acute chemical liver injury.

Materials and Methods

We established a chemical liver injury model induced by carbon tetrachloride (CCl₄) in mice. The flavonoid composition in gonggan (Citrus reticulata Blanco var. gonggan) peel was detected by HPLC. The histopathological sections of liver, related biochemical indicators in serum and liver, and related genes were examined to evaluate the protective effect of gonggan peel flavonoid extract (GPFE).

Results

The results showed that GPFE contained narirutin, hesperidin, nobiletin, tangeretin, and 5-demethylnobiletin. After 14 days of intragastric administration of GPFE, the result showed GPFE could reduce the increase in liver index, serum alanine aminotransferase (ALT), and aspartate transaminase (AST) levels caused by CCl₄. At the same time, pathological sections of liver confirmed that GPFE alleviated the damage to liver tissue. Moreover, biochemical indicator results showed that GPFE increased the activities of superoxide dismutase (SOD) and catalase (CAT) in liver tissue and reduced the content of malondialdehyde (MDA). Also, it reduced the levels of inflammation factors: tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin (IL)-1β, and IL-6. In addition, q-PCR results showed that GPFE upregulated mRNA expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2), copper/zinc superoxide dismutase (SOD1), manganese superoxide dismutase (SOD2), glutathione peroxidase (GSH-Px), γ-glutamylcysteine synthetase (γ-GCS), CAT, and downregulated IL-6 and TNF-α mRNA expression levels. The mechanism of GPFE may be related to the inhibition of oxidative stress and inflammation.

Conclusion

The experiment indicates GPFE has a good protective effect on acute chemical liver injury in mice induced by CCl₄ via antioxidant and anti-inflammatory pathways.

Gensenoside Rg1 protects against lipopolysaccharide- and d-galactose-induced acute liver failure via suppressing HMGB1-mediated TLR4-NF-κB pathway

AIM

Acute liver failure (ALF) is a life-threatening acute liver injury (ALI) with high mortality. Gensenoside Rg1 (G-Rg1) effects on Lipopolysaccharide- (LPS-) and d-galactose-(D-gal-) induced ALI, but its effects on ALF remained unclear. This paper aimed to validate its possible efficacy on ALF prevention.

METHODS

For in vivo studies, histological examination was performed using hematoxylin-eosin (H&E) staining, and alanine aminotransferase (ALT), aspartate aminotransminase (AST), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) contents were measured. Levels of inflammatory cytokines tumor necrosis factor-α (TNF-α) and Interleukin-6 (IL-6) were quantified via enzyme-linked immunosorbent assay (ELISA). Human bronchial epithelial cell line BEAS-2B was used for ALF model in vitro and its viability was measured by MTT assay. Expressions of high mobility group box 1 (HMGB1) and toll-like receptor 4-Nuclear Factor-κB (TLR4-NF-κB) pathway-related proteins were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot as needed.

RESULTS

G-Rg1 relieved LPS- and D-gal-induced hepatic injury, and reduced ALT, AST and MDA levels but upregulated SOD and GSH levels, with downregulation on TNF-α and IL-6 levels. Expressions of HMGB1, TLR4 and NF-κB pathway-related proteins were also down-regulated after G-Rg1 treatment both in vivo and in vitro, while BEAS-2B cell viability was increased. However, overexpressed HMGB1 reversed the effects of G-Rg1 treatment in vitro.

CONCLUSION

G-Rg1 had a protective effect against LPS- and D-gal-induced ALF both in vitro and in vivo, which might be related to inhibited HMGB1-mediated TLR4-NF-κB Pathway. These discoveries suggested that G-Rg1 could be a potential agent for prevention against ALF.

Bioinformatic and biochemical studies of formononetin against liver injure

Formononetin is a promising bioactive phytoestrogen with evident pharmacological properties. However, the potential hepatoprotective benefit is evidenced limitedly in experiments. This study was designed to investigate the hepatoprotective mechanism and benefit of formononetin against liver injury via network pharmacology combined with biochemical determination. The computational data from network pharmacology identified the crucial genes of formononetin against liver injury, listed as TNF-α, NFκB-p65, TLR3, RELA, TRAF6, IKBKG, IKBKB, TNFRSF1A. And the anti-liver injury of formononetin were mainly involved in suppression of inflammatory pathways, including TNF signaling pathway, NF-κB signaling pathway, Toll-like receptor signaling pathway. In animal investigation, formononetin-dosed mice showed reduced body weight loss and hepatomegaly, meliorated liver function, suppressed hepatotoxicity and inflammatory reaction. Furthermore, the down-regulated expressions of TNF-α, NFκB-p65, TLR3 mRNAs and proteins in the livers of formononetin-dosed mice were detected accordingly. Therefore, we concluded that computational findings based on network pharmacology reveal the pharmacological targets, biological processes, and molecular mechanisms of formononetin against liver injury before some of findings were partially certified in vivo. Overall, formononetin may be a potential active component to prevent or treat liver injury.

Sex-linked differences in the course of thioacetamide-induced acute liver failure in Lewis rats

Acute liver failure (ALF) is a clinical syndrome with high mortality rate, resulting from widespread hepatocyte damage. Its pathophysiological background is still poorly understood and preclinical studies evaluating pathophysiology and new potential therapeutic measures are needed. The model of ALF induced by administration of thioacetamide (TAA) in Lewis rats is recommended as optimal; however, the limitation of previous studies was that they were performed predominantly in male rats. In view of the growing recognition that sex as a biological variable should be taken into consideration in preclinical research, we examined its role in the development of TAA-induced ALF in Lewis rats. We found that, first, intact male Lewis rats showed lower survival rate than their female counterparts, due to augmented liver injury documented by higher plasma ammonia, and bilirubin levels and alanine aminotransferase activity. Second, in female rats castration did not alter the course of TAA-induced ALF whereas in the male gonadectomy improved the survival rate and attenuated liver injury, reducing it to levels observed in their female counterparts. In conclusion, we found that Lewis rats show a remarkable sexual dimorphism with respect to TAA-induced ALF, and male rats display dramatically poorer prognosis as compared with the females. We showed that testosterone is responsible for the deterioration of the course of TAA-induced ALF in male rats. In most general terms, our findings indicate that in the preclinical studies of the pathophysiology and treatment of ALF (at least of the TAA-induced form) the sex-linked differences should be seriously considered.

Amphiregulin alleviated concanavalin A-induced acute liver injury via IL-22

OBJECTIVES

Amphiregulin (Areg), a glycoprotein from the epidermal growth factor receptor (EGFR) ligand family, has a well-documented protective role against tissue injury; however, its effects on immune-mediated liver injury are still unclear. Here, we used a concanavalin A (ConA)-induced acute liver hepatitis model to explore the effects of Areg on immune-mediated acute liver injury.

MATERIALS AND METHODS

Some C57BL/6 mice were administered ConA at a dose of 20 mg/kg (model mice), and some received 5 µg of Areg (treated mice). Then, their survival rates over 36 h were analyzed. After 5 h of treatment, liver function, hepatic histology, and apoptosis in liver tissue were investigated, and cytokine expression and neutrophil infiltration and activity in the liver were detected. Moreover, the protective effects of Areg were also evaluated without IL-22 in vivo.

RESULTS

Our results showed that Areg administration increased acute liver failure (ALF) mouse survival, restored liver function, and alleviated liver damage. Interestingly, Areg administration increased IL-22 production in hepatic T cells and upregulated IL-22 concentrations in the serum and liver, whereas IL-22 neutralization completely abolished the therapeutic effect of Areg. Meanwhile, Areg administration was concomitant with increased expression of the anti-apoptotic proteins Bcl-2 and Bcl-xL, which are important in the hepatoprotective mechanism of IL-22.

CONCLUSIONS

Areg showed direct protective effects against ConA-induced acute liver injury, which suggests the potential therapeutic application of Areg in immune-mediated ALF.

Current concepts in acute liver failure

Acute liver failure (ALF) is a severe condition secondary to a myriad of causes associated with poor outcomes. The prompt diagnosis and identification of the aetiology allow the administration of specific treatments plus supportive strategies and to define the overall prognosis, the probability of developing complications and the need for liver transplantation. Pivotal issues are adequate monitoring and the institution of prophylactic strategies to reduce the risk of complications, such as progressive liver failure, cerebral oedema, renal failure, coagulopathies or infections. In this article, we review the main aspects of ALF, including the definition, diagnosis and complications. Also, we describe the standard-of-care strategies and recent advances in the treatment of ALF. Finally, we include our experience of care patients with ALF.

Enhanced Keap1-Nrf2/Trx-1 axis by daphnetin protects against oxidative stress-driven hepatotoxicity via inhibiting ASK1/JNK and Txnip/NLRP3 inflammasome activation

BACKGROUND

Oxidative stress-triggered fatal hepatotoxicity is an essential pathogenic factor in acute liver failure (ALF).

AIMS

To investigate the protective effect of daphnetin (Daph) on tert-butyl hydroperoxide (t-BHP) and acetaminophen (APAP)-induced hepatotoxicity through altering Nrf2/Trx-1 pathway activation.

MATERIALS AND METHODS

In vivo, male C57BL/6 mice with Wild-type (WT) and Nrf2^-/- were divided into five groups and acute liver injury model were established by APAP or LPS/GalN after injection with Daph (20, 40, or 80 mg/kg), seperately. Then, liver tissue and serum were collected for biochemical determination, TUNEL and H & E staining, and western blot analysis. In vitro, HepG2 cells were used to investigate the protective effect and mechanism of daphnetin against ROS and apoptosis induced by t-BHP via apoptosis detection, western blot, immunofluorescence analysis, and sgRNA transfection.

RESULTS

Our results indicated that Daph efficiently inhibited t-BHP-stimulated hepatotoxicity, and modulated Trx-1 expression and Nrf2 activation which decreased Keap1-overexpression in HepG2 cells. Moreover, Daph inhibited t-BHP-excited hepatotoxicity and enhanced Trx-1 expression, which was reversed in Nrf2^-/- HepG2 cells. In vivo, a survival rate analysis first suggested that Daph significantly reduced the lethality induced by APAP or GalN/LPS in a Nrf2-dependent or -independent manner by using Nrf2^-/- mice, respectively. Next, further results implicated that Daph not only effectively alleviated APAP-induced an increase of ALT and AST levels, histopathological changes, ROS overproduction, malondialdehyde (MDA) formation and GSH/GSSG reduction, but it also relieved hepatic apoptosis by strengthening the suppression of cleaved-caspase-3 and expression of P53 protein. Additionally, Daph attenuated mitochondrial dysfunction by suppressing ASK1/JNK activation and decreasing apoptosis-inducing factor (AIF) and Cytochrome c release and Bax mitochondrial translocation. Daph inhibited inflammatory responses by inactivating the thioredoxin-interacting protein (Txnip)/NLRP3 inflammasome. Furthermore, Daph efficiently enhanced Nrf2 nuclear translocation and Trx-1 expression. However, these effects in WT mice were eliminated in Nrf2^-/- mice.

CONCLUSIONS

These investigations demonstrated that Daph treatment has protective potential against oxidative stress-driven hepatotoxicity by inhibition of ASK1/JNK and Txnip/NLRP3 activation, which may be strongly related to the Nrf2/Trx-1 upregulation.

Human liver regeneration following massive hepatic necrosis: Two distinct patterns

BACKGROUND AND AIM

Massive hepatic necrosis is a rare but often fatal complication of various liver injuries. Nevertheless, some patients can survive by spontaneous hepatic regeneration. It is known that surviving hepatocytes and/or progenitor cells can participate in this process but the mechanism of hepatic recovery is vague.

METHODS

We examined 13 explanted human livers removed for acute liver failure. Combined immunohistochemistry, digital image analysis, and three-dimensional reconstruction of serial sections were applied.

RESULTS

Two patterns of regeneration could be distinguished. In livers with centrilobular necrosis, the surviving injured periportal hepatocytes started to proliferate and arrange into acinar structures and expressed α-fetoprotein. If the injury wiped out almost all hepatocytes, large areas of parenchymal loss were invaded by an intense ductular reaction. The cells at the distal pole of the ductules differentiated into hepatocytes and formed foci organized by the branches of the portal vein. The expanding foci often containing complete portal triads were arranged around surviving central veins. Their fusion eventually could be an attempt to re-establish the hepatic lobules.

CONCLUSIONS

Regeneration of human livers following massive hepatic necrosis can occur in two ways-either through proliferation of α-fetoprotein-positive acinary-arranged hepatocytes or through ductular progenitor cells, with the latter being less efficient. Further investigation of these regenerative pathways may help identify biomarkers for likelihood of complete regeneration and hence have therapeutic implications.

Pharmacological stimulation of Wnt/beta-catenin signaling pathway attenuates the course of thioacetamide-induced acute liver failure

Acute liver failure (ALF) is known for extremely high mortality rate, the result of widespread damage of hepatocytes. Orthotopic liver transplantation is the only effective therapy but its application is limited by the scarcity of donor organs. Given the importance in the liver biology of Wnt/beta-catenin signaling pathway, we hypothesized that its stimulation could enhance hepatocyte regeneration and attenuate the course of thioacetamide (TAA)-induced ALF in Lewis rats. Chronic treatment with Wnt agonist was started either immediately after hepatotoxic insult ("early treatment") or when signs of ALF had developed ("late treatment"). Only 23 % of untreated Lewis rats survived till the end of experiment. They showed marked increases in plasma alanine aminotransferase (ALT) activity and bilirubin and ammonia (NH3) levels; plasma albumin decreased significantly. "Early" and "late" Wnt agonist treatment raised the final survival rate to 69 % and 63 %, respectively, and normalized ALT, NH3, bilirubin and albumin levels. In conclusion, the results show that treatment with Wnt agonist attenuates the course of TAA-induced ALF in Lewis rats, both with treatment initiated immediately after hepatotoxic insult and in the phase when ALF has already developed. Thus, the pharmacological stimulation of Wnt/beta-catenin signaling pathway can present a new approach to ALF treatment.

Acute hepatitis and acute liver failure: Pathologic diagnosis and differential diagnosis

Acute hepatitis and acute liver failure are severe medical conditions that require early clinical intervention. Histopathologic findings on a liver biopsy or a liver explant may help identify the underlying etiology or provide an important direction for further clinical, laboratory and radiographical investigation. This review is divided into two main portions. The first portion concentrates on various etiologies and discusses unique histologic features that can be associated with specific etiologies. The second portion describes the general morphologic features based on which the diagnosis of acute hepatitis and acute liver failure are made. Histopathologic distinction between collapse and cirrhosis and limitations of histopathologic assessment for underlying etiologies are addressed in this portion. Another focus of this review is non-necrotic acute liver failure, which typically features diffuse microvesicular steatosis secondary to various etiologies causing mitochondrial dysfunction. Molecular testing serves an increasingly important role in the diagnosis and management of this group of disorders.