Deficiency of leucine-rich repeat kinase 2 aggravates thioacetamide-induced acute liver failure and hepatic encephalopathy in mice.

BACKGROUND: Hepatic encephalopathy (HE) is closely associated with inflammatory responses. However, as a crucial regulator of the immune and inflammatory responses, the role of leucine-rich repeat kinase 2 (LRRK2) in the pathogenesis of HE remains unraveled. Herein, we investigated this issue in thioacetamide (TAA)-induced HE following acute liver failure (ALF). METHODS: TAA-induced HE mouse models of LRRK2 wild type (WT), LRRK2 G2019S mutation (Lrrk2G2019S) and LRRK2 knockout (Lrrk2-/-) were established. A battery of neurobehavioral experiments was conducted. The biochemical indexes and pro-inflammatory cytokines were detected. The prefrontal cortex (PFC), striatum (STR), hippocampus (HIP), and liver were examined by pathology and electron microscopy. The changes of autophagy-lysosomal pathway and activity of critical Rab GTPases were analyzed. RESULTS: The Lrrk2-/--HE model reported a significantly lower survival rate than the other two models (24% vs. 48%, respectively, p < 0.05), with no difference found between the WT-HE and Lrrk2G2019S-HE groups. Compared with the other groups, after the TAA injection, the Lrrk2-/- group displayed a significant increase in ammonium and pro-inflammatory cytokines, aggravated hepatic inflammation/necrosis, decreased autophagy, and abnormal phosphorylation of lysosomal Rab10. All three models reported microglial activation, neuronal loss, disordered vesicle transmission, and damaged myelin structure. The Lrrk2-/--HE mice presented no severer neuronal injury than the other genotypes. CONCLUSIONS: LRRK2 deficiency may exacerbate TAA-induced ALF and HE in mice, in which inflammatory response is evident in the brain and aggravated in the liver. These novel findings indicate a need of sufficient clinical awareness of the adverse effects of LRRK2 inhibitors on the liver.

Endotoxin tolerance ameliorates lipopolysaccharide/D-galactosamine-induced acute liver failure by negative regulation of the NF-κB/NLRP3 and activation of Nrf2/HO-1 via Sitr1.

Acute liver failure (ALF) is a potentially fatal disorder characterized by extensive hepatocyte necrosis and rapid decline in liver function. Numerous factors, including oxidative stress, cell death, and inflammatory responses, are associated with its pathogenesis. Endotoxin tolerance (ET) refers to the phenomenon in which the body or cells exhibit low or no response to high-dose lipopolysaccharide (LPS) stimulation after pre-stimulation with low-dose LPS. However, the specific mechanism through which ET regulates LPS/D-galactosamine (D-GalN)-induced ALF remains unclear. An ALF mouse model was established by intraperitoneal injection of D-GalN (400 mg/kg) and LPS (10 mg/kg). A low dose of LPS (0.1 mg/kg/d) was continuously administered to mice for 5 d before modeling to assess the protective effect of ET. The data from this study showed that ET alleviated the inflammatory response in mice with LPS/D-GalN-induced ALF. ET inhibited LPS-induced oxidative damage and pyroptosis in macrophages in vitro. RNA sequencing analysis showed that the NF-κB/NLRP3 pathway was linked to the anti-inflammatory and antioxidative effects of ET. Furthermore, using western blot, RT-qPCR, and immunofluorescence, we verified that ET inhibited the NF-κB/NLRP3 pathway and triggered the Nrf2/HO-1 signaling pathway to attenuate oxidative stress and cell pyroptosis. Sirt1 knockdown reversed this protective effect. In summary, our research elucidates that ET prevents ALF advancement by upregulating Sirt1 levels, triggering the Nrf2/HO-1 signaling axis, and suppressing the NF-κB/NLRP3 signaling cascade to inhibit oxidative stress and cell pyroptosis. Our results provide a mechanistic explanation for the protective effect of ET against ALF.

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.

Hepatic Sirt6 activation abrogates acute liver failure.

Acute liver failure (ALF) is a deadly illness due to insufficient detoxification in liver induced by drugs, toxins, and other etiologies, and the effective treatment for ALF is very limited. Among the drug-induced ALF, acetaminophen (APAP) overdose is the most common cause. However, the molecular mechanisms underlying APAP hepatoxicity remain incompletely understood. Sirtuin 6 (Sirt6) is a stress responsive protein deacetylase and plays an important role in regulation of DNA repair, genomic stability, oxidative stress, and inflammation. Here, we report that genetic and pharmacological activation of Sirt6 protects against ALF in mice. We first observed that Sirt6 expression was significantly reduced in the liver tissues of human patients with ALF and mice treated with an overdose of APAP. Then we developed an inducible Sirt6 transgenic mice for Cre-mediated overexpression of the human Sirt6 gene in systemic (Sirt6-Tg) and hepatic-specific (Sirt6-HepTg) manners. Both Sirt6-Tg mice and Sirt6-HepTg mice exhibited the significant protection against APAP hepatoxicity. In contrast, hepatic-specific Sirt6 knockout mice exaggerated APAP-induced liver damages. Mechanistically, Sirt6 attenuated APAP-induced hepatocyte necrosis and apoptosis through downregulation of oxidative stress, inflammation, the stress-activated kinase JNK activation, and apoptotic caspase activation. Moreover, Sirt6 negatively modulated the level and activity of poly (ADP-ribose) polymerase 1 (PARP1) in APAP-treated mouse liver tissues. Importantly, the specific Sirt6 activator MDL-800 exhibited better therapeutic potential for APAP hepatoxicity than the current drug acetylcysteine. Furthermore, in the model of bile duct ligation induced ALF, hepatic Sirt6-KO exacerbated, but Sirt6-HepTg mitigated liver damage. Collectively, our results demonstrate that Sirt6 protects against ALF and suggest that targeting Sirt6 activation could be a new therapeutic strategy to alleviate ALF.

Acute liver failure.

ABSTRACT: Acute liver failure, commonly caused by acetaminophen overdose, is associated with numerous systemic complications including cerebral edema, hypotension, acute kidney injury, and infection. Management is primarily supportive, with an emphasis on excellent neurocritical care. Although some antidotes and targeted treatments exist, the only definitive treatment remains orthotopic liver transplant.

Silent information regulator sirtuin 1 ameliorates acute liver failure via the p53/glutathione peroxidase 4/gasdermin D axis.

BACKGROUND: Acute liver failure (ALF) has a high mortality with widespread hepatocyte death involving ferroptosis and pyroptosis. The silent information regulator sirtuin 1 (SIRT1)-mediated deacetylation affects multiple biological processes, including cellular senescence, apoptosis, sugar and lipid metabolism, oxidative stress, and inflammation. AIM: To investigate the association between ferroptosis and pyroptosis and the upstream regulatory mechanisms. METHODS: This study included 30 patients with ALF and 30 healthy individuals who underwent serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) testing. C57BL/6 mice were also intraperitoneally pretreated with SIRT1, p53, or glutathione peroxidase 4 (GPX4) inducers and inhibitors and injected with lipopolysaccharide (LPS)/D-galactosamine (D-GalN) to induce ALF. Gasdermin D (GSDMD)-/- mice were used as an experimental group. Histological changes in liver tissue were monitored by hematoxylin and eosin staining. ALT, AST, glutathione, reactive oxygen species, and iron levels were measured using commercial kits. Ferroptosis- and pyroptosis-related protein and mRNA expression was detected by western blot and quantitative real-time polymerase chain reaction. SIRT1, p53, and GSDMD were assessed by immunofluorescence analysis. RESULTS: Serum AST and ALT levels were elevated in patients with ALF. SIRT1, solute carrier family 7a member 11 (SLC7A11), and GPX4 protein expression was decreased and acetylated p5, p53, GSDMD, and acyl-CoA synthetase long-chain family member 4 (ACSL4) protein levels were elevated in human ALF liver tissue. In the p53 and ferroptosis inhibitor-treated and GSDMD-/- groups, serum interleukin (IL)-1ß, tumour necrosis factor alpha, IL-6, IL-2 and C-C motif ligand 2 levels were decreased and hepatic impairment was mitigated. In mice with GSDMD knockout, p53 was reduced, GPX4 was increased, and ferroptotic events (depletion of SLC7A11, elevation of ACSL4, and iron accumulation) were detected. In vitro, knockdown of p53 and overexpression of GPX4 reduced AST and ALT levels, the cytostatic rate, and GSDMD expression, restoring SLC7A11 depletion. Moreover, SIRT1 agonist and overexpression of SIRT1 alleviated acute liver injury and decreased iron deposition compared with results in the model group, accompanied by reduced p53, GSDMD, and ACSL4, and increased SLC7A11 and GPX4. Inactivation of SIRT1 exacerbated ferroptotic and pyroptotic cell death and aggravated liver injury in LPS/D-GalN-induced in vitro and in vivo models. CONCLUSION: SIRT1 activation attenuates LPS/D-GalN-induced ferroptosis and pyroptosis by inhibiting the p53/GPX4/GSDMD signaling pathway in ALF.

Unconjugated Hyperbilirubinemia in Acetaminophen-Related Acute Liver Failure.

BACKGROUND In the absence of liver transplantation, the natural history of acetaminophen-induced liver failure is characterized by a progressive increase of liver function tests, including bilirubin mainly as its conjugated form. The presence of high levels of unconjugated bilirubin is more unusual; its etiology is unclear and its prognostic factor has been poorly investigated. CASE REPORT A 52-year-old man with a history of chronic analgesics, alcohol, and illicit drug abuse developed acute liver failure in relationship with the ingestion of largely supra-therapeutic doses of acetaminophen over the days preceding admission. The patient received the classical N-acetylcysteine treatment regimen for acetaminophen overdose. Clinical course was characterized by a progressive worsening of the neurological condition, evolving to grade IV encephalopathy. Coagulation disorders persisted, with factor V level <10%. He fulfilled the criteria for liver transplantation, but this option was rejected after a careful psychiatric evaluation. Laboratory investigations revealed a progressive increase in serum unconjugated bilirubin until his death. As evidence for hemolysis was lacking, acquired deficit in bilirubin glucuronidation appeared likely and diagnosis of Gilbert's syndrome was excluded. CONCLUSIONS After the exclusion of other causes of high unconjugated bilirubin levels, the progressive increase in unconjugated bilirubin can reflect a persistent defect in bilirubin conjugation in relationship with liver centrilobular injury, but the relationship with acetaminophen-glucuronidation is not known and there are insufficient data to affirm that the ratio unconjugated/conjugated bilirubin could be used as a prognostic factor.

Dihydroquercetin improves experimental acute liver failure by targeting ferroptosis and mitochondria-mediated apoptosis through the SIRT1/p53 axis.

BACKGROUND: Ferroptosis and mitochondria-mediated apoptosis are both involved in the pathogenesis of acute liver failure (ALF). Ferroptosis-produced reactive oxygen species (ROS) trigger the chain oxidation of polyunsaturated phospholipids and promote mitochondrial apoptosis. Dihydroquercetin (DHQ) also plays an important protective role against liver injury. PURPOSE: Here, we aimed to investigate the protective effects of DHQ on ALF. We also explored the underlying mechanism. METHODS: We established a Lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced ALF mouse model and tumor necrosis factor-α (TNF-α)/D-Gal-induced ALF LO2 cell model. 2',7'-Dichlorofluorescein diacetate (DCFH-DA) and Dihydroethidium (DHE) were used to detect total ROS levels. Lipid ROS was assessed using C11-BODIPY flow cytometry. Lipid peroxidative products levels were detected using MDA ELISA assay and 4-hydroxynonenal (4-HNE) immunohistochemistry. QRT-PCR and western blots were used to test mRNA and protein expression levels, respectively. Cell viability was evaluated with CCK8 assay, and apoptosis was analyzed using flow cytometry. RESULTS: DHQ treatment improved LPS/D-Gal-induced ALF, as well as TNF-α/D-Gal-induced reductions in LO2 viability and increased sirtuin 1 (SIRT1) expression. DHQ pretreatment also reduced the accumulation of ROS, reduced lipid peroxidation, elevated mitochondrial membrane potentials (ΔΨm), and decreased liver cell apoptosis both in vivo and in vitro. Additionally, the knockdown of SIRT1 and p53 activator (Tenovin-6) treatment reversed DHQ's inhibitory effects on ferroptosis and mitochondria-mediated apoptosis in vitro. DHQ enhanced p53 deacetylation by both up-regulating SIRT1 expression and directly bonding to SIRT1. We also found that Tenovin-6's stimulatory effects on ferroptosis and mitochondria-mediated apoptosis in the DHQ-treated LO2 ALF cell model were partially attenuated by overexpression of solute carrier family 7member 11 (SLC7A11), as well as by apoptotic protease activating factor 1 (Apaf-1) knockdown. CONCLUSION: Our results suggest that DHQ alleviated ALF by inhibiting both ferroptosis and mitochondria-mediated apoptosis by regulating the SIRT1/p53 axis. Thus, DHQ may serve as a novel therapy for ALF.

Hyperactivation of succinate dehydrogenase promotes pyroptosis of macrophage via ROS-induced GSDMD oligomerization in acute liver failure.

Acute liver failure (ALF) is a life-threatening disease with high mortality. Given excessive inflammation is one of the major pathogenesis of ALF, candidates targeting inflammation could be beneficial in the condition. Now the effect of hyperactivated succinate dehydrogenase (SDH) on promoting inflammation in lipopolysaccharide (LPS)-treated macrophages has been studied. However, its role and mechanism in ALF is not well understood. Here intraperitoneal injection of D-galactosamine and LPS was conducted in male C57BL/6 J mice to induce the ALF model. Dimethyl malonate (DMM), which inhibited SDH activity, was injected intraperitoneally 30 min before ALF induction. Macrophage pyroptosis was induced by LPS plus adenosine triphosphate (ATP). Pyroptosis-related molecules and proteins including GSDMD oligomer were examined by ELISA and western blot techniques, respectively. ROS production was assessed by fluorescence staining. The study demonstrated SDH activity was increased in liver macrophages from ALF mice. Importantly, DMM administration inhibited ROS, IL-1ß, and pyroptosis-associated proteins levels (NLRP3, cleaved caspase-1, GSDMD-N, and GSDMD oligomers) both in the ALF model and in macrophages stimulated with LPS plus ATP. In vitro, ROS promoted pyroptosis by facilitating GSDMD oligomerization. Additionally, when ROS levels were increased through the addition of H2O2 to the DMM group, the levels of GSDMD oligomers were reverted. In conclusion, SDH hyperactivation promotes macrophage pyroptosis by ROS-mediated GSDMD oligomerization, suggesting that targeting this pathway holds promise as a strategy for treating ALF and other inflammatory diseases.

miRNA­21 promotes the progression of acute liver failure via the KLF6/autophagy/IL­23 signaling pathway.

Acute liver failure (ALF) is a complex syndrome characterized by overactivation of innate immunity, and the recruitment and differentiation of immune cells at inflammatory sites. The present study aimed to explore the role of microRNA (miRNA/miR)­21 and its potential mechanisms underlying inflammatory responses in ALF. Baseline serum miR­21 was analyzed in patients with ALF and healthy controls. In addition, miR­21 antagomir was injected via the tail vein into C57BL/6 mice, and lipopolysaccharide/D­galactosamine (LPS/GalN) was injected into mice after 48 h. The expression levels of miR­21, Krüppel­like­factor­6 (KLF6), autophagy­related proteins and interleukin (IL)­23, and hepatic pathology were then assessed in the liver tissue. Furthermore, THP­1­derived macrophages were transfected with a miRNA negative control, miR­21 inhibitor, miR­21 mimics or KLF6 overexpression plasmid, followed by treatment with or without rapamycin, and the expression levels of miR­21, KLF6, autophagy­related proteins and IL­23 were evaluated. The results revealed that baseline serum miR­21 levels were significantly upregulated in patients with ALF. In addition, LPS/GalN­induced ALF was attenuated in the antagomir­21 mouse group. KLF6 was identified as a target of miR­21­5p with one putative seed match site identified by TargetScan. A subsequent luciferase activity assay demonstrated a direct interaction between miR­21­5p and the 3'­UTR of KLF6 mRNA. Further experiments suggested that miR­21 promoted the expression of IL­23 via inhibiting KLF6, which regulated autophagy. In conclusion, in the present study, baseline serum miR­21 levels were highly upregulated in patients with ALF, antagomir­21 attenuated LPS/GalN­induced ALF in a mouse model, and miR­21 could promote the expression of IL­23 via inhibiting KLF6.

Preclinical efficacy and safety of encapsulated proliferating human hepatocyte organoids in treating liver failure.

Alginate-encapsulated hepatocyte transplantation is a promising strategy to treat liver failure. However, its clinical application was impeded by the lack of primary human hepatocytes and difficulty in controlling their quality. We previously reported proliferating human hepatocytes (ProliHHs). Here, quality-controlled ProliHHs were produced in mass and engineered as liver organoids to improve their maturity. Encapsulated ProliHHs liver organoids (eLO) were intraperitoneally transplanted to treat liver failure animals. Notably, eLO treatment increased the survival of mice with post-hepatectomy liver failure (PHLF) and ameliorated hyperammonemia and hypoglycemia by providing liver functions. Additionally, eLO treatment protected the gut from PHLF-augmented permeability and normalized the increased serum endotoxin and inflammatory response, which facilitated liver regeneration. The therapeutic effect of eLO was additionally proved in acetaminophen-induced liver failure. Furthermore, we performed assessments of toxicity and biodistribution, demonstrating that eLO had no adverse effects on animals and remained non-tumorigenic.

Unexpected Amanita phalloides-Induced Hematotoxicity-Results from a Retrospective Study.

INTRODUCTION: Amanita phalloides poisoning is a serious health problem with a mortality rate of 10-40%. Poisonings are characterized by severe liver and kidney toxicity. The effect of Amanita phalloides poisonings on hematological parameters has not been systematically evaluated thus far. METHODS: Patients with suspected Amanita phalloides poisonings were retrospectively selected from the hospital database of the University Medical Center Groningen (UMCG). Medical data-including demographics; liver, kidney, and blood parameters; treatment; and outcomes-were collected. The severity of the poisoning was scored using the poison severity score. RESULTS: Twenty-eight patients were identified who were admitted to the UMCG with suspected Amanita phalloides poisoning between 1994 and 2022. A time-dependent decrease was observed for hemoglobin and hematocrit concentrations, leukocytes, and platelets. Six out of twenty-eight patients developed acute liver failure (ALF). Patients with ALF showed a higher increase in liver enzymes, international normalized ratios, and PSS compared to patients without ALF. Conversely, hemoglobin and platelet numbers were decreased even further in these patients. Three out of six patients with ALF died and one patient received a liver transplant. CONCLUSION: Our study shows that Amanita phalloides poisonings may be associated with hematotoxicity in patients. The quantification of hematological parameters is of relevance in intoxicated patients, especially in those with ALF.

Modulation of the crosstalk between Keap1/Nrf2/HO-1 and NF-κB signaling pathways by Tomatidine protects against inflammation/oxidative stress-driven fulminant hepatic failure in mice.

Fulminant hepatic failure (FHF) is the terminal phase of acute liver injury, which is characterized by massive hepatocyte necrosis and rapid hepatic dysfunction in patients without preexisting liver disease. There are currently no therapeutic options for such a life-threatening hepatic failure except liver transplantation; therefore, the terminal phase of the underlying acute liver injury should be avoided. Tomatidine (TOM), asteroidal alkaloid, may have different biological activities, including antioxidant and anti-inflammatory effects. Herein, the lipopolysaccharide (LPS)/D-galactosamine (D-GalN)-induced FHF mouse model was established to explore the protective potential of TOM and the underlying mechanisms of action. TOM pretreatment significantly inhibited hepatocyte necrosis and decreased serum aminotransferase activities in LPS/D-GalN-stimulated mice. TOM further increased the level of different antioxidant enzymes while reducing lipid peroxidation biomarkers in the liver. These beneficial effects of TOM were shown to be associated with targeting of NF-κB signaling pathways, where TOM repressed NF-κB activation and decreased LPS/D-GalN-induced TNF-α, IL-6, IL-1ß, and iNOS production. Moreover, TOM prevented LPS/D-GalN-induced upregulation of Keap1 expression and downregulation of Nrf2 and HO-1 expression, leading to increased Nrf2-binding activity and HO-1 levels. Besides, TOM pretreatment repressed LPS/D-GalN-induced upregulation of proliferating cell nuclear antigen (PCNA) expression, which spared the hepatocytes from damage and subsequent repair following the LPS/D-GalN challenge. Collectively, our findings revealed that TOM has a protective effect on LPS/D-GalN-induced FHF in mice, showing powerful antioxidant and anti-inflammatory effects, primarily mediated via modulating Keap1/Nrf2/HO-1 and NF-κB/TNF-α/IL-6/IL-1ß/iNOS signaling pathways.

Oral administration of grape-derived nanovesicles for protection against LPS/D-GalN-induced acute liver failure.

Although the exploration of the molecular mechanisms of Acute liver failure (ALF) is supported by a growing number of studies, the lack of effective therapeutic agents and measures indicates an urgent clinical need for the development of new drugs and treatment strategies. Herein, we focused on the treatment of ALF with grape-derived nanovesicles (GDNVs), and assessed its protective effects and molecular mechanisms against liver injury. In the mice model of ALF, prophylactic administration for three consecutive days and treatment with GDNVs after successful induction of ALF showed a significant reduction of ALT and AST activity in mouse serum, as well as a blockade of the release of inflammatory cytokines IL6, IL-1ß and TNF-α. Treatment with GDNVs significantly prevented the massive apoptosis of hepatocytes caused by LPS/D-GalN and down-regulated the activation and expression of the mitochondrial apoptosis-related proteins p53, Caspase 9, Caspase 8, Caspase 3 and Bax. GDNVs downregulated the release of chemokines during the inflammatory eruption in mice and inhibited the infiltration of peripheral monocytes into the liver by inhibiting CCR2/CCR5. Moreover, the pro-inflammatory phenotype of macrophages in the liver was reversed by GDNVs. GDNVs further reduced the activation of NLRP3-related pathways, and treatment with GDNVs activated the expression of autophagy-related proteins Foxo3a, Sirt1 and LC3-II in the damaged mouse liver, inducing autophagy to occur. GDNVs could exert hepatoprotective and inflammatory suppressive functions by increasing nuclear translocation of Nrf2 and upregulating HO-1 expression against exogenous toxin-induced oxidative stress in the liver. In conclusion, these results demonstrate that GDNVs alleviate LPS/D-GalN-induced ALF and have the potential to be used as a novel hepatoprotective agent for clinical treatment.

Biomarker discovery in acetaminophen hepatotoxicity: leveraging single-cell transcriptomics and mechanistic insight.

INTRODUCTION: Acetaminophen (APAP) overdose is the leading cause of drug-induced liver injury and can cause a rapid progression to acute liver failure (ALF). Therefore, the identification of prognostic biomarkers to determine which patients will require a liver transplant is critical for APAP-induced ALF. AREAS COVERED: We begin by relating the mechanistic investigations in mouse models of APAP hepatotoxicity to the human APAP overdose pathophysiology. We draw insights from the established sequence of molecular events in mice to understand the progression of events in the APAP overdose patient. Through this mechanistic understanding, several new biomarkers, such as CXCL14, have recently been evaluated. We also explore how single-cell RNA sequencing, spatial transcriptomics, and other omics approaches have been leveraged for identifying novel biomarkers and how these approaches will continue to push the field of biomarker discovery forward. EXPERT OPINION: Recent investigations have elucidated several new biomarkers or combination of markers such as CXCL14, a regenerative miRNA signature, a cell death miRNA signature, hepcidin, LDH, CPS1, and FABP1. While these biomarkers are promising, they all require further validation. Larger cohort studies analyzing these new biomarkers in the same patient samples, while adding these candidate biomarkers to prognostic models will further support their clinical utility.

'Double whammy': An Unusual Co-occurrence of Idiosyncratic phenytoin-induced agranulocytosis and acute liver failure in a child.

Idiosyncratic adverse events to phenytoin therapy, such as agranulocytosis and acute liver failure, though rare, may be life-threatening. Simultaneous occurrence of both adverse events is exceedingly rare; only two cases have been reported in the literature to date. We describe such a case in a 15-year-old girl. Prompt haematological and hepatic recovery occurred after discontinuation of the drug. Given the widespread use of phenytoin in seizure disorders, clinicians prescribing this drug should be aware of its potential complications. Early recognition can considerably improve outcomes.

Human umbilical cord mesenchymal stem cells protect against ferroptosis in acute liver failure through the IGF1-hepcidin-FPN1 axis and inhibiting iron loading.

Acute liver failure (ALF) is a significant global issue with elevated morbidity and mortality rates. There is an urgent and pressing need for secure and effective treatments. Ferroptosis, a novel iron-dependent regulation of cell death, plays a significant role in multiple pathological processes associated with liver diseases, including ALF. Several studies have demonstrated that mesenchymal stem cells (MSCs) have promising therapeutic potential in the treatment of ALF. This study aims to investigate the positive effects of MSCs against ferroptosis in an ALF model and explore the underlying molecular mechanisms of their therapeutic function. Our results show that intravenously injected MSCs protect against ferroptosis in ALF mouse models. MSCs decrease iron deposition in the liver of ALF mice by downregulating hepcidin level and upregulating FPN1 level. MSCs labelled with Dil are mainly observed in the hepatic sinusoid and exhibit colocalization with the macrophage marker CD11b fluorescence. ELISA demonstrates a high level of IGF1 in the CCL 4+MSC group. Suppressing the IGF1 effect by the PPP blocks the therapeutic effect of MSCs against ferroptosis in ALF mice. Furthermore, disruption of IGF1 function results in iron deposition in the liver tissue due to impaired inhibitory effects of MSCs on hepcidin level. Our findings suggest that MSCs alleviate ferroptosis induced by disorders of iron metabolism in ALF mice by elevating IGF1 level. Moreover, MSCs are identified as a promising cell source for ferroptosis treatment in ALF mice.

AGK2 pre-treatment protects against thioacetamide-induced acute liver failure via regulating the MFN2-PERK axis and ferroptosis signaling pathway.

BACKGROUND: Acute liver failure (ALF) is an unpredictable and life-threatening critical illness. The pathological characteristic of ALF is massive necrosis of hepatocytes and lots of inflammatory cells infiltration which may lead to multiple organ failure. METHODS: Animals were divided into 3 groups, normal, thioacetamide (TAA, ALF model) and TAA + AGK2. Cultured L02 cells were divided into 5 groups, normal, TAA, TAA + mitofusin 2 (MFN2)-siRNA, TAA + AGK2, and TAA + AGK2 + MFN2-siRNA groups. The liver histology was evaluated with hematoxylin and eosin staining, inositol-requiring enzyme 1 (IRE1), activating transcription factor 6ß (ATF6ß), protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) and phosphorylated-PERK (p-PERK). C/EBP homologous protein (CHOP), reactive oxygen species (ROS), MFN2 and glutathione peroxidase 4 (GPX4) were measured with Western blotting, and cell viability and liver chemistry were also measured. Mitochondria-associated endoplasmic reticulum membranes (MAMs) were measured by immunofluorescence. RESULTS: The liver tissue in the ALF group had massive inflammatory cell infiltration and hepatocytes necrosis, which were reduced by AGK2 pre-treatment. In comparison to the normal group, apoptosis rate and levels of IRE1, ATF6ß, p-PERK, CHOP, ROS and Fe2+ in the TAA-induced ALF model group were significantly increased, which were decreased by AGK2 pre-treatment. The levels of MFN2 and GPX4 were decreased in TAA-induced mice compared with the normal group, which were enhanced by AGK2 pre-treatment. Compared with the TAA-induced L02 cell, apoptosis rate and levels of IRE1, ATF6ß, p-PERK, CHOP, ROS and Fe2+ were further increased and levels of MFN2 and GPX4 were decreased in the MFN2-siRNA group. AGK2 pre-treatment decreased the apoptosis rate and levels of IRE1, ATF6ß, p-PERK, CHOP, ROS and Fe2+ and enhanced the protein expression of MFN2 and GPX4 in MFN2-siRNA treated L02 cell. Immunofluorescence observation showed that level of MAMs was promoted in the AGK2 pre-treatment group when compared with the TAA-induced group in both mice and L02 cells. CONCLUSIONS: The data suggested that AGK2 pre-treatment had hepatoprotective role in TAA-induced ALF via upregulating the expression of MFN2 and then inhibiting PERK and ferroptosis pathway in ALF.

A retrospective study to evaluate Hy's Law, DrILTox ALF score, Robles-Diaz model, and a new logistic regression model for predicting acute liver failure in Chinese patients with drug-induced liver injury.

OBJECTIVES: To evaluate Hy's law, DrILTox ALF Score, Robles-Diaz Model, and a new logistic regression model for predicting acute liver failure (ALF) in Chinese patients with drug-induced liver injury (DILI). METHODS: We conducted a retrospective study among 514 hospitalized DILI patients from 2011 to 2020. Logistic regression analysis was used to develop a predictive model for ALF. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of these models were compared. Another 304 DILI patients were used for external validation. OUTCOMES: Twenty-six of 514 DILI patients progressed to ALF. Among these models, Hy's law had 84.6% sensitivity, 59.8% specificity, 10.1% PPV, and 98.6% NPV. DrILTox ALF Score had 92.3% sensitivity, 51.8% specificity, 9.3% PPV, and 99.2% NPV, while Robles-Diaz Model had 50.0% sensitivity, 77.7% specificity, 10.7% PPV, and 96.7% NPV. The logistic regression model described as P = 1/(1+e(1.643 - 0.006* × TBIL (µmol/L) -- 1.302* × INR + 0.095* × ALB (g/L))) had 88.5% sensitivity, 73.1% specificity, 16.3% PPV, and 99.1% NPV at the cut-off of 0.04778 and kept 94.4% sensitivity, 66.8% specificity, 15.2% PPV, and 99.5% NPV in external validation. CONCLUSIONS: The logistic regression model provided superior performance than Hy's law, DrILTox ALF Score, and Robles-Diaz Model for predicting DILI -related ALF.