Toxin-induced Liver Injury Research Articles

A Case of Ratol Poisoning Review of Literature

We report a case of a 17 year old lady who presented with severe abdominal pain for 4 days. Patient developed fulminant hepatitis and disseminated intravascular coagulation during her hospital stay. History of Ratol (3% yellow phosphorus) ingestion was revealed on the second day of admission. She was managed with NAC infusion for 3 days along with supportive treatment and was discharged on the 10th day of admission. Accidental ingestion of Ratol is common in rural India. Early diagnosis and management of yellow phosphorus can improve the outcome of the patient. It is important to identify predictors of outcome of patients with toxin-induced liver injury.

Resveratrol Alleviated T-2 Toxin-Induced Liver Injury via Preservation of Nrf2 Pathway and GSH Synthesis.

T-2 toxin is a trichothecene mycotoxin and is considered as an extremely inevitable pollutant with potent hepatotoxicity. However, the approach to alleviation of T-2 toxin-triggered hepatotoxicity has been recognized as a serious challenge. Resveratrol (Res) is a polyphenol natural product isolated from various plant species, but its protective effect against T-2 toxin hepatotoxicity and detailed mechanism remains obscure. In the present study, the effect of Res against the hepatotoxicity was evaluated, and the underlying mechanisms were further revealed in mice. Functionally, Res inhibited liver injury, oxidative damage, and mitochondrial dysfunction induced by T-2 toxin. Mechanistically, Res modulated Nrf2-mediated antioxidant pathway and glutathione synthesis inhibition. Collectively, our findings first showed beyond doubt that Res ameliorated T-2 toxin-triggered liver injury by regulating Nrf2 pathways in mice.

Inhibition of Macrophage Pyroptosis─A New Therapeutic Strategy to Alleviate T-2 Toxin-Induced Subacute Liver Injury by Directly Competing with the Key Target.

Multiple compounds are related to the development of liver injury, such as toxins, drugs, and environmental pollutants. Although there are reports that the T-2 toxin can cause liver injury, its toxic mechanism remains unclear, which further impedes the development of effective antidotes. In this study, CRISPR-Cas9 genome-wide screening technology was used to identify transformation-related protein 53 inducible nuclear protein 1 (trp53inp1) as a toxic target of the T-2 toxin. Mechanism studies have shown that the T-2 toxin induced pyroptosis of macrophages (J774A.1 cells) by activating the trp53inp1/NF-κB/NLRP3/GSDMD-N pathway, leading to a subacute liver injury. Also, the new drug berberine (BER) identified through virtual screening significantly alleviated the subacute liver injury by competitively binding trp53inp1 via His224; the effect was better than those of the positive control drugs N-acetylcysteine (NAC) and disulfiram (DSF). In summary, the above results indicate that trp53inp1 is a key target for T-2 toxin to induce subacute liver injury and that inhibiting macrophage pyroptosis is a new method for treating liver injury. In addition, this study provides a new method and strategy for the discovery of key disease targets and the search for effective drugs.

Toxin-Induced Liver Injury and Extracorporeal Treatment of Liver Failure.

Poisoning with a large variety of drugs and naturally occurring toxins may result in acute liver injury and failure. Drug-induced liver injury is a major cause of liver failure nationwide, and it is likely that nephrologists will be involved in treating patients with these conditions. A number of xenobiotics resulting in liver toxicity may cause acute kidney injury or other organ injury as well. Most agents causing drug- or toxin-induced liver failure lack specific therapies, although a few xenobiotics such as acetaminophen have effective antidotal therapies if administered prior to development of hepatotoxicity. The nephrologist should be aware that extracorporeal treatment of liver failure associated with drugs and toxins may be indicated, including therapies conventionally performed by nephrologists (hemodialysis, continuous kidney replacement therapy), therapies occasionally performed by nephrologists and other specialists (plasma exchange, albumin dialysis, hemadsorption), and therapies performed by other specialists (extracorporeal membrane oxygenation). An overview of the role of these therapies in liver failure is provided, as well as a review of their limitations and potential complications.

Clinico-etiological profile of chronic liver disease in females: A cross-sectional observational study in Eastern Indian set-up

Abstract Background: There are notable distinctions in the epidemiology, progression, symptoms, and treatment responses observed between males and females with chronic liver disease (CLD). Women tend to exhibit a higher prevalence of acute liver failure, autoimmune hepatitis, benign liver lesions, primary biliary cirrhosis, and toxin-induced liver injury compared with men. This study investigated the clinical and pathological characteristics of CLD in female patients admitted to a tertiary healthcare facility in eastern India. Materials and Methods: An observational cross-sectional study was conducted involving adult female patients meeting the criteria for CLD. Comprehensive medical histories were obtained, physical examinations were conducted, and various investigations were performed, including complete blood count, liver function tests, urea, creatinine, and electrolyte levels. Additionally, all cases underwent whole abdomen ultrasound, with selected cases undergoing further viral profiling and upper gastrointestinal workups. The collected data underwent statistical analysis. Results: Among the 80 cases of CLD examined in our study, 62.5% fell within the age range of 41–60 years. Metabolic dysfunction associated with steatohepatitis (MASH) and hepatitis C were identified as the primary causes of CLD, collectively accounting for 50% of all cases. Specifically, 25% of cases were attributed solely to hepatitis C, whereas another 25% were attributed solely to MASH. Additionally, two cases presented with a combination of MASH and hepatitis C. Pallor and jaundice were the most frequently observed clinical findings. Notably, autoimmune hepatitis tended to occur in younger females, whereas MASH was more prevalent in those aged over 51 years. Conclusion: There are distinctions based on gender concerning the causes, advancement, natural course, complications, and outlook of CLD cases. Therefore, it is essential to consider gender-specific traits when diagnosing and treating CLD in females.

Liver infiltration of multiple immune cells during the process of acute liver injury and repair.

Immune cells, including neutrophils, natural killer (NK) cells, T cells, NKT cells and macrophages, participate in the progression of acute liver injury and hepatic recovery. To date, there has been no systematic study on the quantitative changes in these different immune cells from initial injury to subsequent recovery. To investigate the infiltration changes of various immune cells in acute liver injury models over time, and to study the relationship between the changes in leukocyte cell-derived chemotaxin 2 (LECT2) and the infiltration of several immune cells. Carbon tetrachloride- and concanavalin A-induced acute liver injury models were employed to mimic toxin-induced and autoimmune-mediated liver injury respectively. The quantitative changes in various immune cells were monitored at different time points. Serum samples were collected, and liver tissues were harvested. Ly6G, CD161, CD4, CD8 and F4/80 staining were used to indicate neutrophils, NK/NKT cells, CD4+ T cells, CD8+ T cells and macrophages, respectively. Lect2-KO mice were used to detect the function of LECT2. During the injury and repair process, different types of immune cells began to increase, reached their peaks and fell into decline at different time points. Furthermore, when the serum alanine transaminase (ALT) and aspartate transaminase (AST) indices reverted to normal levels 7 d after the injury, the infiltration of immune cells still existed even 14 d after the injury, showing an obvious lag effect. We found that the expression of LECT2 was upregulated in acute liver injury mouse models, and the liver injuries of Lect2-KO mice were less severe than those of wild-type mice. Compared with wild-type mice, Lect2-KO mice had different immune cell infiltration. The recovery time of immune cells was far behind that of serum ALT and AST during the process of liver repair. LECT2 could regulate monocyte/macrophage chemotaxis and might be used as a therapeutic target for acute liver injury.

S3333 Aloe Vera: A Boon or Bane

Introduction: Aloe Vera is derived from a cactus-like plant, a member of the Lily family that grows best in arid climates. Aloe Vera products are derived from the leaf and contain over 75 identified substances including anthraquinones, vitamins (A, C, E), enzymes, minerals, sugars, fatty acids, amino acids, salicylic acid and hormones. Aloe has been widely used in phytomedicine and is described as a herb which has anti-inflammatory, anti-proliferative, anti-aging effects. Case Description/Methods: 54-year-old male with a history of Hashimoto's thyroiditis, Gilbert's syndrome, came to ER with RUQ abdominal pain. He used to drink 4-5 glasses of wine everyday and quit 3 months ago. Also reported dark urine and a 4 pound weight loss over a month. He has been taking Aloe Vera supplements for gut motility for 4 months. Had scleral icterus and hepatosplenomegaly on exam. Labs showed elevated total bilirubin of 8.1 with direct hyperbilirubinemia(5.3) , ALP of 163, ALT 2790, AST 1892. Work up ruled out acetaminophen toxicity, viral and autoimmune hepatitis. Abdominal US showed hepatic cyst and small amount of sludge in the gallbladder without biliary ductal dilation. Liver biopsy showed an acute hepatitis pattern of injury with no fibrosis/cirrhosis. Aloe Vera supplements were discontinued and LFTs started trending down and repeat values after 10 days showed total bilirubin of 3.4, ALP 133, ALT 1308, AST 506. LFTs have almost normalized after 1 month. Discussion: Cases of Aloe Vera-induced hepatotoxicity have been reported since 2005 but its pharmacokinetics and toxicity are poorly described in literature. It has been reported in multiple countries with the most in Switzerland. Injury typically arises between 3 and 24 weeks after starting oral Aloe Vera. Typical pattern of injury is hepatocellular and the clinical course resembles acute viral hepatitis. Injury is rarely severe and fatal cases have not been reported. Most cases of hepatotoxicity from Aloe Vera have been self-limiting upon discontinuing it. Few cases have been severe or prolonged, but no instances leading to liver transplantation, chronic hepatitis, or vanishing bile duct syndrome. Rechallenge has led to recurrence of injury in at least one published case report and should be avoided. Our case was one of the examples of rare cases of acute toxin induced liver injury secondary to herbal products. Though Aloe Vera has its benefits, patients should be discouraged from using OTC supplements containing this product as the data on the safety is scarce.

Notch-Regulated c-Kit-Positive Liver Sinusoidal Endothelial Cells Contribute to Liver Zonation and Regeneration.

Background & AimsLiver sinusoidal endothelial cells (SECs) promote the proliferation of hepatocytes during liver regeneration. However, the specific subset of SECs and its mechanisms during the process remain unclear. In this study, we investigated the potential role of c-kit+ SECs, a newly identified subset of SECs in liver regeneration.MethodsPartial hepatectomy mice models were established to induce liver regeneration. Hepatic c-kit expression was detected by quantitative reverse-transcription polymerase chain reaction, immunofluorescent staining, and fluorescence-activated cell sorting. VE-cadherin-cyclization recombinase-estrogen receptor (Cdh5-Cre-ERT) Notch intracellular domain and Cdh5-Cre recombination signal binding protein Jκfloxp mice were introduced to mutate Notch signaling. c-Kit+ SECs were isolated by magnetic beads. Single-cell RNA sequencing was performed on isolated SECs. Liver injuries were induced by CCl4 or quantitative polymerase chain reaction injection.ResultsHepatic c-kit is expressed predominantly in SECs. Liver resident SECs contribute to the increase of c-kit during partial hepatectomy–induced liver regeneration. Isolated c-kit+ SECs promote hepatocyte proliferation in vivo and in vitro by facilitating angiocrine. The distribution of c-kit shows distinct spatial differences that are highly coincident with the liver zonation marker wingless-type MMTV integration site family, member2 (Wnt2). Notch mutation reshapes the c-kit distribution and liver zonation, resulting in altered hepatocyte proliferation. c-Kit+ SECs were shown to regulate hepatocyte regeneration through angiocrine in a Wnt2-dependent manner. Activation of the Notch signaling pathway weakens liver regeneration by inhibiting positive regulatory effects of c-kit+ SECs on hepatocytes. Furthermore, c-kit+ SEC infusion attenuates toxin-induced liver injuries in mice.ConclusionsOur results suggest that c-kit+ SECs contributes to liver zonation and regeneration through Wnt2 and is regulated by Notch signaling, providing opportunities for novel therapeutic approaches to liver injury in the future. Transcript profiling: GEO (accession number: GSE134037).

Fibroblast growth factor receptor 3 in hepatocytes protects from toxin-induced liver injury and fibrosis

SummaryThe liver's remarkable regenerative capacity is orchestrated by several growth factors and cytokines. Fibroblast growth factor receptor 3 (Fgfr3) is frequently overexpressed in hepatocellular carcinoma and promotes cancer aggressiveness, whereas its role in liver homeostasis, repair and regeneration is unknown. We show here that Fgfr3 is expressed by hepatocytes in the healthy liver. Its major ligand, Fgf9, is mainly expressed by non-parenchymal cells and upregulated upon injury. Mice lacking Fgfr3 in hepatocytes exhibit increased tissue necrosis after acute toxin treatment and more excessive fibrosis after long-term injury. This was not a consequence of immunological alterations in the non-injured liver as revealed by comprehensive flow cytometry analysis. Rather, loss of Fgfr3 altered the expression of metabolic and pro-fibrotic genes in hepatocytes. These results identify a paracrine Fgf9-Fgfr3 signaling pathway that protects from toxin-induced cell death and the resulting liver fibrosis and suggests a potential use of FGFR3 ligands for therapeutic purposes.

Protective effect of selenomethionine on T-2 toxin-induced liver injury in New Zealand rabbits

BackgroundT-2 toxin is a mycotoxin produced by Fusarium species that is highly toxic to animals. Recent studies have indicated that Selenomethionine (SeMet) have protective effect against mycotoxins-induced toxicity. The aim of the present study was to investigate the protective effect of SeMet on T-2-toxin-induced liver injury in rabbit and explore its molecular mechanism. Fifty rabbits (30 d, 0.5 ± 0.1 kg) were randomly divided into 5 groups: control group, T-2 toxin group, low, medium and high dose SeMet treatment group. The SeMet-treated group was orally pretreated with SeMet (containing selenium 0.2 mg/kg, 0.4 mg/kg and 0.6 mg/kg) for 21 days. On the 17th day, T-2 toxin group and SeMet-treated group were orally administered with T-2 toxin (0.4 mg/kg body weight) for 5 consecutive days.ResultsThe results showed that low-dose SeMet significantly improved T-2 toxin-induced liver injury. We found that low-dose SeMet can reduce the level of oxidative stress and the number of hepatocyte apoptosis. Moreover, the levels of Bax, caspase-3 and caspase-9 were significantly reduced and the levels of Bcl-2 were increased.ConclusionsTherefore, we confirmed that low-dose SeMet may protect rabbit hepatocytes from T-2 toxin by inhibiting the mitochondrial-caspase apoptosis pathway.

Etiology and Outcome of Acute Liver Failure in Children—The Experience of a Single Tertiary Care Hospital from Romania

Background: Acute liver failure (ALF) is a rare disease, associated with high mortality, despite optimal medical therapy without emergency liver transplantation. Knowing the possible cause of ALF plays a vital role in the management, as the child could benefit from effective specific therapies in emergencies. Methods: We have analyzed the etiology and outcome of ALF in children followed-up in a tertiary care hospital between January 2012–December 2018. The patients were grouped into different age categories: neonates (0–1 month), infants (1–12 months), children (1–14 years), and teenagers (14–18 years). Results: 97 children (46 males, 47.42%, the mean age of 7.66 ± 8.18 years) were admitted with ALF. The most important causes of ALF were in neonates and infants, infections (72.72%), and metabolic disorders (43.47%), in children and adolescents were the toxic causes (60% and 79.41%). The mortality rate was 31.95% (31 patients), mainly in ALF due to infections or metabolic disorders. Conclusions: In neonates and infants, the main causes of ALF were infections and metabolic diseases, while in older children and teenagers, were toxin-induced liver injuries. The mortality among neonates and infants was significantly higher than in other ages. Early recognition and immediate therapeutic intervention could improve the outcome of these patients.

Mechanisms of wolfberry in the treatment of liver diseases

<p indent=0mm>The fruit of <italic>Lycium barbarum</italic> (the wolfberry or goji berry) has been widely used as a drug and functional food in many traditional Chinese medicine literature. However, only in recent years has its specific health-promoting mechanism been investigated. Modern technology of pharmacology has identified a variety of bioactive ingredients from the Goji berry, such as polysaccharide, pigments, and lycibarbarspermidines, with properties of anti-inflammation, antioxidant, anti-apoptosis, anti-fibrosis, and anti-tumor. Acute and chronic liver diseases represent a major world public health problem. The clinical curative rate for some liver diseases, such as chronic hepatitis B, cirrhosis, and liver cancer remains unsatisfactorily low. In the current review, we summarized the updated mechanisms of bioactive ingredients derived from the Goji berry in liver diseases, which may pave the way for their future clinical application. The hepatoprotective properties of <italic>Lycium barbarum</italic> polysaccharide (LBP) have been characterized in several liver disease models, including acute liver injury, liver failure, non-alcoholic liver disease, alcoholic liver disease, liver fibrosis, and liver cancer. However, delineating the active ingredient(s) from LBP in different types of liver diseases is a challenge. Wolfberry also contains the highest concentration of the antioxidant xanthophyll carotenoid zeaxanthin dipalmitate (ZD). ZD is a zeaxanthin diester formed from zeaxanthin (ZE) and palmitic acid. Inducing non-alcoholic in the transgenic HBV mice model reactivated HBV replication, while ZD administration reduced HBV DNA replication and serum HBsAg levels. The immediate hepatocyte membrane receptors of ZD during alcoholic liver injury have also be identified. Treating human adipose-derived mesenchymal stem cells (hADMSC) with ZD before transplantation increased stem cell survival and improved the therapeutic outcome in acute liver disease/failure models. Betaine is a natural amino acid and one of the major constituents of <italic>Lycium barbarum</italic>. It is shown to play antioxidant and anti-inflammatory roles in toxin-induced liver injury and fatty liver disease model. Recently, we identified fifteen new dicaffeoylspermidine derivatives, lycibarbarspermidines A-O, from wolfberry. The oxygen radical absorbance capacity assay revealed that A-O all displayed antioxidant capacity and are related to the effects of wolfberry. Our pilot study results also revealed their potential hepatoprotective properties in alcoholic and non-alcoholic liver diseases. Of note, all published papers reported no side effects from LBP, ZD, betaine, or lycibarbarspermidines. Nonetheless, since the investigation of the properties of herbal active compounds is on the rise and with wolfberry’s increasing popularity and commercialization as a food supplement, those major ingredients will likely get more attention from the scientific community, and its effect on liver disease might be studied further.

HYPERGLYCEMIA AGGRAVATES ACUTE LIVER INJURY BY PROMOTING LIVER-RESIDENT MACROPHAGE NLRP3 INFLAMMASOME ACTIVATION VIA THE INHIBITION OF AMPK/MTOR-MEDIATED AUTOPHAGY INDUCTION

Key Laboratory of Liver Transplantation, Chinese Academy of Medical Sciences, Nanjing, China. NHC Key Laboratory of Living Donor Liver Transplantation, Nanjing, China Although the detrimental effects of diabetes mellitus/hyperglycemia have been observed in many liver disease models, the function and mechanism of hyperglycemia regulating liver-resident macrophages, Kupffer cells (KCs), in thioacetamide (TAA)-induced liver injury remain largely unknown. In this study, we evaluated the role of hyperglycemia in regulating NOD-like receptor family pyrin domain-containing 3 protein (NLRP3) inflammasome activation by inhibiting autophagy induction in KCs in the TAA-induced liver injury model. Type I diabetes/hyperglycemia was induced by streptozotocin treatment. Compared with the control group, hyperglycemic mice exhibited a significant increase in intrahepatic inflammation and liver injury. Enhanced NLRP3 inflammasome activation was detected in KCs from hyperglycemic mice, as shown by increased gene induction and protein levels of NLRP3, cleaved caspase-1, apoptosis-associated speck-like protein containing a caspase recruitment domain and interleukin-1β, compared with control mice. NLRP3 inhibition by its antagonist CY-09 effectively suppressed inflammasome activation in KCs and attenuated liver injury in hyperglycemic mice. Furthermore, inhibited autophagy activation was revealed by transmission electron microscope detection, decreased LC3B protein expression and p-62 protein degradation in KCs isolated from TAA-stressed hyperglycemic mice. Interestingly, inhibited 5’ AMP-activated protein kinase (AMPK) but enhanced mammalian target of rapamycin (mTOR) activation was found in KCs from TAA-stressed hyperglycemic mice. AMPK activation by its agonist 5- aminoimidazole-4-carboxamide ribonucleotide (AICAR) or mTOR signaling knockdown by small interfering RNA restored autophagy activation, and subsequently, inhibited NLRP3 inflammasome activation in KCs, leading to ultimately reduced TAA-induced liver injury in the hyperglycemic mice. Our findings demonstrated that hyperglycemia aggravated TAA-induced acute liver injury by promoting liver-resident macrophage NLRP3 inflammasome activation via inhibiting AMPK/mTOR-mediated autophagy. This study provided a novel target for prevention of toxin-induced acute liver injury under hyperglycemia. National Natural Science Foundation of China (81571564). CAMS Innovation Fund for Medical Sciences (No.2019-I2M-5-035). The Foundation of Jiangsu Collaborative Innovation Center of Biomedical Functional Materials. The 863 Young Scientists Special Fund (SS2015AA0209322).

Attenuated fibrosis in specific pathogen-free microbiota in experimental cholestasis- and toxin-induced liver injury.

In advanced chronic liver disease (CLD), the translocation of intestinal bacteria and the resultant increase of proinflammatory cytokines in the splanchnic and systemic circulation may contribute to the progression of fibrosis. We therefore speculated that fibrosis and portal hypertension (PHT) would be attenuated in a mouse model of limited intestinal colonization with altered Schaedler flora (ASF) compared to a more complex colonization with specific pathogen-free (SPF) flora. We induced liver fibrosis in ASF and SPF mice by common bile duct ligation (BDL) or by carbon tetrachloride (CCl4) treatment. We then measured portal pressure (PP), portosystemic shunts (PSSs), and harvested tissues for further analyses. There were no differences in PP between sham-treated ASF or SPF mice. After BDL or CCl4 treatment, PP, PSSs, and hepatic collagen deposition increased in both groups. However, the increase in PP and the degree of fibrosis was significantly higher in ASF than SPF mice. Expression of fibrotic markers α-smooth muscle actin, desmin, and platelet-derived growth factor receptor β were significantly higher in ASF than SPF mice. This was associated with higher activation of hepatic immune cells (macrophages, neutrophils) and decreased expression of the intestinal epithelial tight junction proteins (claudin-1, occludin-1). In 2 models of advanced CLD, SPF mice presented significantly attenuated liver injury, fibrosis, and PHT compared to ASF mice. In contrast to our hypothesis, these findings suggest that a complex intestinal microbiota may play a "hepato-protective" role.-Moghadamrad, S., Hassan, M., McCoy, K. D., Kirundi, J., Kellmann, P., De Gottardi, A. Attenuated fibrosis in specific pathogen-free microbiota in experimental cholestasis- and toxin-induced liver injury.

Epidemiology and outcomes of acute liver failure in Australia.

BACKGROUNDAcute liver failure (ALF) is a life-threatening syndrome with varying aetiologies requiring complex care and multidisciplinary management. Its changing incidence, aetiology and outcomes over the last 16 years in the Australian context remain uncertain.AIMTo describe the changing incidence, aetiology and outcomes of ALF in South Eastern Australia.METHODSThe database of the Victorian Liver Transplant Unit was interrogated to identify all cases of ALF in adults (> 16 years) in adults hospitalised between January 2002 and December 2017. Overall, 169 patients meeting criteria for ALF were identified. Demographics, aetiology of ALF, rates of transplantation and outcomes were collected for all patients. Transplant free survival and overall survival (OS) were assessed based on survival to discharge from hospital. Results were compared to data from a historical cohort from the same unit from 1988-2001.RESULTSParacetamol was the most common aetiology of acute liver failure, accounting for 50% of cases, with an increased incidence compared with the historical cohort (P = 0.046). Viral hepatitis and non-paracetamol drug or toxin induced liver injury accounted for 15% and 10% of cases respectively. Transplant free survival (TFS) improved significantly compared to the historical cohort (52% vs 38%, P = 0.032). TFS was highest in paracetamol toxicity with spontaneous recovery in 72% of cases compared to 31% of non-paracetamol ALF (P < 0.001). Fifty-nine patients were waitlisted for emergency liver transplantation. Nine of these died while waiting for an organ to become available. Forty-two patients (25%) underwent emergency liver transplantation with a 1, 3 and 5 year survival of 81%, 78% and 72% respectively.CONCLUSIONParacetamol toxicity is the most common aetiology of ALF in South-Eastern Australia with a rising incidence over 30 years. TFS has improved, however it remains low in non-paracetamol ALF.

Hyperglycemia exacerbates acetaminophen-induced acute liver injury by promoting liver-resident macrophage proinflammatory response via AMPK/PI3K/AKT-mediated oxidative stress

Although diabetes mellitus/hyperglycemia is a risk factor for acute liver injury, the underlying mechanism remains largely unknown. Liver-resident macrophages (Kupffer cells, KCs) and oxidative stress play critical roles in the pathogenesis of toxin-induced liver injury. Here, we evaluated the role of oxidative stress in regulating KC polarization against acetaminophen (APAP)-mediated acute liver injury in a streptozotocin-induced hyperglycemic murine model. Compared to the controls, hyperglycemic mice exhibited a significant increase in liver injury and intrahepatic inflammation. KCs obtained from hyperglycemic mice secreted higher levels of the proinflammatory factors, such as TNF-α and IL-6, lower levels of the anti-inflammatory factor IL-10. Furthermore, enhanced oxidative stress was revealed by increased levels of reactive oxygen species (ROS) in KCs from hyperglycemic mice post APAP treatment. In addition, ROS inhibitor NAC resulted in a significant decrease of ROS production in hyperglycemic KCs from mice posttreated with APAP. We also analyzed the role of hyperglycemia in macrophage M1/M2 polarization. Interestingly, we found that hyperglycemia promoted M1 polarization, but inhibited M2 polarization of KCs obtained from APAP-exposed livers, as evidenced by increased MCP-1 and inducible NO synthase (iNOS) gene induction but decreased Arg-1 and CD206 gene induction accompanied by increased STAT1 activation and decreased STAT6 activation. NAC restored Arg-1, CD206 gene induction, and STAT6 activation. To explore the mechanism how hyperglycemia regulates KCs polarization against APAP-induced acute liver injury, we examined the AMPK/PI3K/AKT signaling pathway and found decreased AMPK activation and increased AKT activation in liver and KCs from hyperglycemic mice post APAP treatment. AMPK activation by its agonist AICAR or PI3K inhibition by its antagonist LY294002 inhibited ROS production in KCs from hyperglycemic mice post APAP treatment and significantly attenuated APAP-induced liver injury in the hyperglycemic mice, compared to the control mice. Our results demonstrated that hyperglycemia exacerbated APAP-induced acute liver injury by promoting liver-resident macrophage proinflammatory response via AMPK/PI3K/AKT-mediated oxidative stress.

DNA methylation is involved in pro-inflammatory cytokines expression in T-2 toxin-induced liver injury

Currently, T-2 toxin has been reported to cause liver toxicity with the effects of oxidative stress and inflammation; however, the underlying mechanism of T-2 toxin-induced liver injury is not fully understood. Increasing lines of evidence show that DNA methylation affects the expression of inflammatory cytokine, and plays a crucial role in autoimmune diseases. Nevertheless, the potential role of DNA methylation in the hepatotoxicity of T-2 toxin has not been explored. In this study, female Wistar rats were given a single dose of T-2 toxin at 2 mg/kg b.w. and were sacrificed at 1, 3 and 7 days post-exposure. In vitro, a normal rat liver cell line (BRL) was exposed to different concentrations of T-2 toxin. Histopathological analysis was used to investigate damage to the liver, which was detected at the molecular level by RT-PCR, Western blot and immunohistochemical assays, methylation-specific PCR (MSP), bisulfite sequencing (BSP), and flow cytometry. The results showed that T-2 toxin significantly increased the levels of DNA methyltransferases (DNMT1, DNMT3A), which were mainly concentrated at the site of liver injury. The 5-methylcytosine (5-mC) level of genomic DNA was also raised in T-2 toxin-treated rat livers. The expression of inflammatory cytokines (IL-6, IL-1β, IL-11, IL-1α, and TNF-α) increased both in vivo and in vitro under T-2 toxin treatment. Notably, DNA demethylation directly increased the expression of cytokines IL-11, IL-6, IL-α, and TNF-α under T-2 toxin exposure. DNA methylation inhibitors combined with T-2 toxin directly or indirectly induced the production of inflammatory cytokines and aggravate cell apoptosis. Our study uncovered for the first time that DNA methylation is related to the expression of inflammatory cytokines in T-2 toxin-induced liver injury. These findings suggested that DNA methylation is a potential mechanism of T-2 toxin-induced hepatotoxicity.

Human amnion epithelial cells and their soluble factors reduce liver fibrosis in murine non-alcoholic steatohepatitis.

Non-alcoholic steatohepatitis (NASH) can lead to cirrhosis and hepatocellular carcinoma. Currently, lifestyle modification is the only effective treatment. We have shown that human amnion epithelial cells (hAECs) reduce inflammation and fibrosis in toxin-induced liver injury models. We examined the effect of these cells and the soluble factors released by the cells into culture medium (hAEC conditioned medium [hAEC-CM]) in a diet-induced murine NASH model. C57BL/6J male mice received a Western "fast food diet" for 42weeks. Group 1 received an intraperitoneal injection of 2×106 hAECs at week 34, group 2 received an additional hAEC dose at week 38, and group 3 received thrice weekly hAEC-CM injections intraperitoneal for 8weeks from week 34. Liver fibrosis area, inflammation, and fibrosis regulators were measured by immunohistochemistry, qPCR, and gelatin zymography. Metabolic parameters were also assessed. Fast food diet-fed mice demonstrated peri-cellular hepatic fibrosis, inflammation, and steatosis typical of NASH. Liver fibrosis area was reduced by 40% in hAEC-treated and hAEC-CM-treated mice. hAEC treatment significantly reduced pSMAD 2/3 signaling and the number of activated hepatic stellate cells and liver macrophages. Matrix metalloproteinase 2 and 9 gene and protein expression were variably affected. hAEC treatment did not alter the NASH activity score or metabolic parameters such as bodyweight, total cholesterol, or glucose tolerance. Human amnion epithelial cell and hAEC-CM significantly reduced hepatic inflammation and fibrosis in a diet-induced non-alcoholic fatty liver disease model. Although hAEC and hAEC-CM did not affect the metabolic components of NASH, their therapeutic potential is promising and warrants further investigation.

Spermine Alleviates Acute Liver Injury by Inhibiting Liver-Resident Macrophage Pro-Inflammatory Response Through ATG5-Dependent Autophagy.

Liver-resident macrophages (Kupffer cells, KCs) and autophagy play critical roles in the pathogenesis of toxin-induced liver injury. Recent evidence indicates that autophagy can regulate macrophage M1/M2 polarization under different inflammatory conditions. Polyamines, including putrescine, spermidine, and spermine (SPM), are polycations with anti-oxidative, anti-aging, and cell autophagy induction properties. This study aimed to determine the mechanisms by which SPM protects against thioacetamide (TAA)-induced acute liver injury in a mouse model. Pretreatment with SPM significantly alleviated liver injury and reduced intrahepatic inflammation in TAA-induced liver injury compared to controls. SPM markedly inhibited M1 polarization, but promoted M2 polarization of KCs obtained from TAA-exposed livers, as evidenced by decreased IL-1β and iNOS gene induction but increased Arg-1 and Mrc-1 gene induction accompanied by decreased STAT1 activation and increased STAT6 activation. Furthermore, pretreatment with SPM enhanced autophagy, as revealed by increased LC3B-II levels, decreased p62 protein expression, and increased ATG5 protein expression in TAA-treated KCs. Knockdown of ATG5 in SPM-pretreated KCs by siRNA resulted in a significant increase in pro-inflammatory TNF-α and IL-6 secretion and decreased anti-inflammatory IL-10 secretion after TAA treatment, while no significant changes were observed in cytokine production in the TAA treatment alone. Additionally, the effect of SPM on regulation of KC M1/M2 polarization was abolished by ATG5 knockdown in TAA-exposed KCs. Finally, in vivo ATG5 knockdown in KCs abrogated the protective effect of SPM against TAA-induced acute liver injury. Our results indicate that SPM-mediated autophagy inhibits M1 polarization, while promoting M2 polarization of KCs in TAA-treated livers via upregulation of ATG5 expression, leading to attenuated liver injury. This study provides a novel target for the prevention of acute liver injury.

Mkp-1 protects mice against toxin-induced liver damage by promoting the Nrf2 cytoprotective response.

The present study was undertaken to investigate the possible protective effect of mitogen-activated protein kinase phosphatase 1 (Mkp-1) on toxin-induced hepatic injury. Here, we uncovered a positive feedback loop between Mkp-1, a dual threonine/tyrosine phosphatase, and nuclear factor erythroid 2-related factor 2 (Nrf2), a crucial regulator of the defense system in the liver. Mkp-1-/- mice exhibited decreased protein levels of Nrf2, phase II gene products, and reduced glutathione (GSH) in the liver. Induction of detoxifying enzymes by the Nrf2 activator butylated hydroxyanisole (BHA) or sulforaphane, was attenuated in the liver and small intestines of Mkp-1-/- mice, indicating that the Nrf2 signaling pathway is impaired as a result of Mkp-1 deficiency. Mkp-1-/- mice suffered more severe liver injury after a single exposure to hepatotoxin carbon tetrachloride (CCl4) than their wild-type (WT) counterparts. BHA partially rescued the CCl4-induced liver damage in WT mice, but not in Mkp-1-/- mice, suggesting the requirement of Mkp-1 in the activation of Nrf2 signaling against the liver injury. Mechanistically, Mkp-1 upregulated Nrf2 through a direct interaction with the Neh2 domain in the transcription factor, while Nrf2 enhanced the expression of Mkp-1 mRNA by binding to the ARE site at -1719 to -1710bp in the Mkp-1 promoter. Our results reveal novel role of Mkp-1 in the maintenance of redox homeostasis in the liver. Thus, strategies aimed at augmenting Mkp-1 expression may be beneficial in protecting the liver and may provide novel therapeutic approaches to toxin-induced liver injury.