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.

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.

[Effect of recombinant human thrombopoietin on platelets in rats with D-galactosamine salt-induced acute liver failure].

OBJECTIVE: To evaluate the effects of recombinant human thrombopoietin (rhTPO) on platelet count (PLT) and liver function in acute liver failure (ALF) rats by observing the dynamic changes of PLT, thrombopoietin (TPO) and liver function during ALF. METHODS: Twenty-four male Sprague-Dawley (SD) rats were divided into model group, TPO group and interleukin-11 (IL-11) group using a random number table method, with eight rats in each group. All rats were intraperitoneally injected with D-galactosamine (D-GalN, 1 500 mg/kg, dosed within 72 hours) to induce the ALF model. After modeling, rats in TPO group was received subcutaneous injection of 15 µg/kg of rhTPO for 5 days, and rats in IL-11 group was received subcutaneous injection of 0.45 mg/kg of IL-11 for 5 days. Venous blood samples were collected before and at 1, 3, 5, 7 and 12 days after molding for whole blood cell detection. The level of TPO in serum was detected by enzyme-linked immunosorbent assay (ELISA). Liver function indexes including serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBil) and albumin (ALB) were measured before and at 1, 3 and 5 days after modeling. The rats were sacrificed 12 days after the modeling, and the pathological changes of liver tissue were observed by hematoxylin-eosin (HE) staining. RESULTS: Two rats in each group died within 24-48 hours after modeling. HE staining showed that all three groups of ALF rats showed large flake necrosis of hepatocytes, disorder of hepatic lobular structure, mesh scaffold collapse, hepatic sinus congestion and hemorrhage, and flake infiltration of inflammatory cells on day 12 after modeling. The levels of serum ALT, AST and TBil of rats in each group were significantly increased 1 day after modeling and then decreased. The level of ALB decreased significantly on the first day after modeling and then increased, but there was no significant difference in the trend of liver function indexes among the three groups. PLT in the three groups decreased rapidly on day 1 after modeling, and then recovered gradually with the improvement of liver function. The PLT of the TPO group rose to the peak value 7 days after molding and was significantly higher than that of the model group [PLT (×109/L): 1 673.3±347.5 vs. 855.3±447.0, P < 0.05], while there was no significant difference between the IL-11 group and the model group [PLT (×109/L): 1 350.3±386.6 vs. 855.3±447.0, P > 0.05]. The level of serum TPO of the three groups increased significantly on day 1 after modeling, then decreased, and dropped to the lowest value on day 5, but there was no significant difference in the trend of serum TPO level among the three groups. CONCLUSIONS: PLT in ALF rats decreased rapidly in the early stage and recovered gradually with the improvement of liver function, and the serum TPO level increased first and then decreased. Injection of rhTPO can significantly increase PLT in ALF rats, but has no significant effect on liver function and survival rate.

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.

[Activation of Yes-associated protein (YAP) improves mouse acute liver failure by alleviating ferroptosis].

Objective To investigate the effects of YAP on the occurrence and progression of acute liver failure by regulating the ferroptosis pathway and its underlying mechanism. Methods A total of 20 8-week-old C57BL/6 mice were randomly divided into four groups: a control group, an acute liver failure model group, a YAP agonist XMU-MP-1 treatment group and a YAP inhibitor verteporfin treatment group, five mice for each group. HE staining was used to observe the pathological changes of hepatic inflammation and necrosis. Plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were detected by liver biochemistry. Iron (Fe), malondialdehyde (MDA), glutathione (GSH) determination kits were used to measure their levels in liver tissues of each group. The changes of hepatocyte mitochondrial in each group were observed by electron microscopy. Real time PCR and Western blot analysis were used to detect the mRNA and protein expressions of YAP, glutathione peroxidase 4 (GPX4) and 5-lipoxygenase (5-LOX). Results Compared with the control group, mice in the acute liver failure model group and the YAP inhibitor verteporfin treatment group showed severe liver tissue congestion with inflammatory cell infiltration and structural damage to hepatic lobules. Liver injury was alleviated in the XMU-MP-1 treatment group. With the occurrence of liver failure, plasma ALT and AST levels significantly increased, and liver function was improved in XMU-MP-1 treatment group. Electron microscopy showed that mitochondria in hepatocytes of mice with liver failure became smaller and bilayer membrane density increased, while mitochondria changes in the XMU-MP-1 group were alleviated. In addition, the acute liver failure model group showed an increase in Fe and MDA contents, decreased protein expressions of GPX4, and enhanced expression of 5-LOX, suggesting that ferroptosis was involved in acute liver failure in C57BL/6 mice. Ferroptosis was inhibited by activation of YAP. Conclusion Activation of YAP may ameliorate liver injury by inhibiting ferroptosis.

Sulforaphane, an NRF2 agonist, alleviates ferroptosis in acute liver failure by regulating HDAC6 activity.

OBJECTIVE: Acute liver failure (ALF) is characterized by severe liver dysfunction, rapid progression and high mortality and is difficult to treat. Studies have found that sulforaphane (SFN), a nuclear factor E2-related factor 2 (NRF2) agonist, has anti-inflammatory, antioxidant and anticancer effects, and has certain protective effects on neurodegenerative diseases, cancer and liver fibrosis. This paper aimed to explore the protective effect of SFN in ALF and it possible mechanisms of action. METHODS: Lipopolysaccharide and D-galactosamine were used to induce liver injury in vitro and in vivo. NRF2 agonist SFN and histone deacetylase 6 (HDAC6) inhibitor ACY1215 were used to observe the protective effect and possible mechanisms of SFN in ALF, respectively. Cell viability, lactate dehydrogenase (LDH), Fe2+, glutathione (GSH) and malondialdehyde (MDA) were detected. The expression of HDAC6, NRF2, glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long-chain family member 4 (ACSL4) and solute carrier family 7 member 11 (SLC7A11) were detected by Western blotting and immunofluorescence. RESULTS: Our results show that NRF2 was activated by SFN. LDH, Fe2+, MDA and ACSL4 were downregulated, while GSH, GPX4 and SLC7A11 were upregulated by SFN in vitro and in vivo, indicating the inhibitory effect of SFN on ferroptosis. Additionally, HDAC6 expression was decreased in the SFN group, indicating that SFN could downregulate the expression of HDAC6 in ALF. After using the HDAC6 inhibitor, ACY1215, SFN further reduced HDAC6 expression and inhibited ferroptosis, indicating that SFN may inhibit ferroptosis by regulating HDAC6 activity. CONCLUSION: SFN has a protective effect on ALF, and the mechanism may include reduction of ferroptosis through the regulation of HDAC6. Please cite this article as: Zhang YQ, Shi CX, Zhang DM, Zhang LY, Wang LW, Gong ZJ. Sulforaphane, an NRF2 agonist, alleviates ferroptosis in acute liver failure by regulating HDAC6 activity. J Integr Med. 2023; 21(5): 464-473.

Artificial cells delivering itaconic acid induce anti-inflammatory memory-like macrophages to reverse acute liver failure and prevent reinjury.

Hepatic macrophages represent a key cellular component of the liver and are essential for the progression of acute liver failure (ALF). We construct artificial apoptotic cells loaded with itaconic acid (AI-Cells), wherein the compositions of the synthetic plasma membrane and surface topology are rationally engineered. AI-Cells are predominantly localized to the liver and further transport to hepatic macrophages. Intravenous administration of AI-Cells modulates macrophage inflammation to protect the liver from acetaminophen-induced ALF. Mechanistically, AI-Cells act on caspase-1 to suppress NLRP3 inflammasome-mediated cleavage of pro-IL-1ß into its active form in macrophages. Notably, AI-Cells specifically induce anti-inflammatory memory-like hepatic macrophages in ALF mice, which prevent constitutive overproduction of IL-1ß when liver reinjury occurs. In light of AI-Cells' precise delivery and training of memory-like hepatic macrophages, they offer promising therapeutic potential in reversing ALF by finely controlling inflammatory responses and orchestrating liver homeostasis, which potentially affect the treatment of various types of liver failure.

Long-term outcomes following ABO-incompatible living donor liver transplantation for acute liver failure: a single-center experience of over 20 years.

PURPOSE: Acute liver failure is a life-threatening condition for which ABO-incompatible living donor liver transplantation (ABOi-LDLT) is sometimes the only life-saving treatment option. We reviewed a single-center experience of adult ABOi-LDLT treatment for acute liver failure (ALF). METHODS: Preoperative treatment, immune indices (B cell marker, anti-donor blood-type antibody), and postoperative outcomes were compared between ALF and non-ALF groups. RESULTS: There were 5 and 33 patients in the ALF and non-ALF groups, respectively. The ALF group received higher doses of steroids, underwent more rounds of plasma exchange (PE), and underwent transplantation for ALF with a shorter interval following preoperative rituximab (RTx) administration (median: 2 vs 13 days; P < 0.05) than the non-ALF group. Preoperatively, CD19-positive lymphocytes in the peripheral blood were sufficiently depleted in all of the non-ALF group patients, whereas they were poorly depleted in the ALF group. Postoperatively, neither group suffered anti-donor blood-type antibody titer rebound or antibody-mediated rejection. The ALF group had a comparable 5-year survival rate to the non-ALF group (80.0% vs 77.9%). CONCLUSIONS: Despite the delayed preoperative administration of RTx, the ALF group showed an uneventful immunological response and acceptable long-term survival rate. Thus, ABOi-LDLT seems a viable treatment option for ALF.

Swertia cincta Burkill alleviates LPS/D-GalN-induced acute liver failure by modulating apoptosis and oxidative stress signaling pathways.

Swertia cincta Burkill is widely distributed along the southwestern region of China. It is known as "Dida" in Tibetan and "Qingyedan" in Chinese medicine. It was used in folk medicine to treat hepatitis and other liver diseases. To understand how Swertia cincta Burkill extract (ESC) protects against acute liver failure (ALF), firstly, the active ingredients of ESC were identified using liquid chromatography-mass spectrometry (LC-MS), and further screening. Next, network pharmacology analyses were performed to identify the core targets of ESC against ALF and further determine the potential mechanisms. Finally, in vivo experiments as well as in vitro experiments were conducted for further validation. The results revealed that 72 potential targets of ESC were identified using target prediction. The core targets were ALB, ERBB2, AKT1, MMP9, EGFR, PTPRC, MTOR, ESR1, VEGFA, and HIF1A. Next, KEGG pathway analysis showed that EGFR and PI3K-AKT signaling pathways could have been involved in ESC against ALF. ESC exhibits hepatic protective functions via anti-inflammatory, antioxidant, and anti-apoptotic effects. Therefore, the EGFR-ERK, PI3K-AKT, and NRF2/HO-1 signaling pathways could participate in the therapeutic effects of ESC on ALF.

Role of N-acetylcysteine in liver injury due to dengue fever.

Dengue fever (DF) is a common mosquito-borne viral infection which is endemic in Southeast Asia. Liver involvement may vary from asymptomatic elevation of liver enzymes to fulminant hepatitis. Although the valuable effects of N-acetylcysteine (NAC) in paracetamol toxicity and non-paracetamol liver failure have been extensively studied, its use in DF-associated hepatitis remains unclear. We made a literature search in an online format from libraries such as PubMed, Google Scholar, and EMBASE, and selected 33 articles including original research articles, case reports, and systemic analyses. The majority of the articles reviewed had a positive outcome but treatment strategies involved NAC together with supportive care. Hence, data on sole use of NAC from large randomised control trials remain unclear.

A Biomimetic Nanoparticle Exerting Protection against Acute Liver Failure by Suppressing CYP2E1 Activity and Scavenging Excessive ROS.

Acute liver failure (ALF) is a severe liver disease caused by many reasons. One of them is the overdosed acetaminophen (APAP), which is metabolized into N-acetyl-p-benzoquinone imine (NAPQI), an excessive toxic metabolite, by CYP2E1, resulting in excessive reactive oxygen species (ROS), exhausted glutathione (GSH), and thereafter hepatocyte necrosis. N-acetylcysteine is the Food and Drug Administration-approved drug for detoxification of APAP, but it has limited clinical application due to the short therapeutic time window and concentration-related adverse effects. In this study, a carrier-free and bilirubin dotted nanoparticle (B/BG@N) is developed, which is formed using bilirubin and 18ß-Glycyrrhetinic acid, and bovine serum albumin (BSA) is then adsorbed to mimic the in vivo behavior of the conjugated bilirubin for hitchhiking. The results demonstrate that B/BG@N can effectively reduce the production of NAPQI as well as exhibit antioxidant effects against intracellular oxidative stress via regulating the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 signal axis and reducing the production of inflammatory factors. In vivo study shows that B/BG@N can effectively improve the clinical symptom of the mice model. This study suggests that B/BG@N own increases circulation half-life, improves accumulation in the liver, and dual detoxification, providing a promising strategy for clinical ALF treatment.

Fluorofenidone protects against acute liver failure in mice by regulating MKK4/JNK pathway.

AIMS: Acute liver failure (ALF) is a life-threatening disease characterized by abrupt and extensive hepatic necrosis and apoptosis, resulting in high mortality. The approved drug, N-acetylcysteine (NAC), is only effective for acetaminophen (APAP)-associated ALF at the early stage. Thus, we investigate whether fluorofenidone (AKF-PD), a novel antifibrosis pyridone agent, protects against ALF in mice and explore its underlying mechanisms. METHODS: ALF mouse models were established using APAP or lipopolysaccharide/D-galactosamine (LPS/D-Gal). Anisomycin and SP600125 were used as JNK activator and inhibitor, respectively, and NAC served as a positive control. Mouse hepatic cell line AML12 and primary mouse hepatocytes were used for in vitro studies. RESULTS: AKF-PD pretreatment alleviated APAP-induced ALF with decreased necrosis, apoptosis, reactive oxygen species (ROS) markers, and mitochondrial permeability transition in liver. Additionally, AKF-PD alleviated mitochondrial ROS stimulated by APAP in AML12 cells. RNA-sequencing in the liver and subsequent gene set enrichment analysis showed that AKF-PD significantly impacted MAPK and IL-17 pathway. In vitro and in vivo studies demonstrated that AKF-PD inhibited APAP-induced phosphorylation of MKK4/JNK, while SP600125 only inhibited JNK phosphorylation. The protective effect of AKF-PD was abolished by anisomycin. Similarly, AKF-PD pretreatment abolished hepatotoxicity caused by LPS/D-Gal, decreased ROS levels, and diminished inflammation. Furthermore, unlike NAC, AKF-PD, inhibited the phosphorylation of MKK4 and JNK upon pretreatment, and improved survival in cases of LPS/D-Gal-induced mortality with delayed dosing. CONCLUSIONS: In summary, AKF-PD can protect against ALF caused by APAP or LPS/D-Gal, in part, via regulating MKK4/JNK pathway. AKF-PD might be a novel candidate drug for ALF.

Mortality associated with the development of acute liver failure after a single dose of nivolumab.

AIM: Immune-related adverse events (irAEs) caused by immune checkpoint inhibitors are reported in all organs; however, the frequency of liver injury is low compared to irAEs in other organs. We describe a case of fulminant hepatitis after administration of the first dose of nivolumab for the management of esophageal cancer. METHODS: A man in his 80s was treated with nivolumab as a second-line therapy after his overall health worsened during preoperative chemotherapy for esophageal cancer. He was admitted to the hospital as an emergency case 30 days later with complaints of vomiting, following which acute liver failure was diagnosed. RESULTS: The patient developed hepatic encephalopathy on the third day after admission and died on the seventh day. The pathological results showed sub-extensive spread hepatocellular necrosis throughout the liver, and immunostaining confirmed the presence of CD8-positive cells, which is consistent with irAEs. CONCLUSIONS: Immune checkpoint inhibitors have proven to be effective for the treatment of malignant tumors, and although fatalities due to acute liver failure are extremely rare, such cases have been reported previously. Among the immune checkpoint inhibitors, anti-programmed death-1 receptor is associated with less hepatotoxicity. However, even a single dose of this treatment can cause acute liver failure, which could be fatal.

Geraniol ameliorates acute liver failure induced by lipopolysaccharide/D-galactosamine via regulating macrophage polarization and NLRP3 inflammasome activation by PPAR-γ methylation Geraniol alleviates acute liver failure.

Geraniol (Ger), a natural acyclic monoterpene alcohol, has been reported to exert protective effects through anti-inflammation in Acute liver failure (ALF). However, its specific roles and precise mechanisms underlying anti-inflammatory effects in ALF have not yet fully explored. We aimed to investigated the hepatoprotective effects and mechanisms of Ger against ALF induced by lipopolysaccharide (LPS)/D-galactosamine (GaIN). In this study, the liver tissue and serum of LPS/D-GaIN-induced mice were collected. The degree of liver tissue injury was evaluated by HE and TUNEL staining. Serum levels of liver injury markers (ALT and AST) and inflammatory factors were measured by ELISA assays. PCR and western blotting were conducted to determine the expression of inflammatory cytokines, NLRP3 inflammasome-related proteins, PPAR-γ pathway-related proteins, DNA Methyltransferases and M1/M2 polarization cytokines. Immunofluorescence staining was used to assess the localization and expression of macrophage markers (F4/80 and CD86), NLRP3 and PPAR-γ. In vitro experiments were performed in macrophages stimulated with LPS with or without IFN-γ. Purification of macrophages and cell apoptosis was analyzed using flow cytometry. We found that Ger effectively alleviated ALF in mice, specified by the attenuation of liver tissue pathological damage, inhibition of ALT, AST and inflammatory factor levels, and inactivation of NLRP3 inflammasome. Meanwhile, downregulation M1 macrophage polarization may involve in the protective effects of Ger. In vitro, Ger reduced the activation of NLRP3 inflammasome and apoptosis through regulating PPAR-γ methylation by inhibiting M1 macrophage polarization. In conclusion, Ger protects against ALF through suppressing NLRP3 inflammasome-mediated inflammation and LPS-induced macrophage M1 polarization via modulating PPAR-γ methylation.

Pharmacokinetic profile of acyclovir in a child receiving continuous kidney replacement therapy for acute liver failure.

BACKGROUND: Continuous venovenous hemodiafiltration (CVVHDF) is one of the treatments of critically ill children presenting severe acute liver failure. This affliction might be induced by HSV infection requiring a treatment by acyclovir. Continuous kidney replacement therapy (CKRT) can alter its pharmacokinetics, according to its physicochemical properties and CVVHDF settings. CASE-DIAGNOSIS/TREATMENT: The patient was a 21-month-old female presenting liver failure with hyperammonemia treated by acyclovir with presumed HSV infection. CKRT was initiated on day 1 with substantial replacement and dialysate flow rates (respectively 75 and 220 mL/kg/h). Acyclovir was intravenously administered every 8 h with a 1-h infusion of 500 mg/m2. Plasma and effluent concentrations were measured by liquid chromatography-tandem mass spectrometry assay to estimate the area under a curve (AUC) and CKRT clearance by 2 methods (one based on pre- and post-filter concentrations and the other one on dialysate flow rates). Clearance was estimated between 19.2 and 26.3 mL/min with the first method and between 27.6 and 44.3 mL/min with the second one. Concentrations were highly above the therapeutic index (peak concentration was measured at 28 mg/L), but AUC was appropriate. CONCLUSIONS: This case describes acyclovir pharmacokinetics during CKRT in a pediatric patient treated by acyclovir. The patient was treated with adapted exposure with the usual dosing, but lower dosing should be investigated with complementary studies. TRIAL REGISTRATION: ClinicalTrials.gov NCT02539407.

CB2R agonist GW405833 alleviates acute liver failure in mice via inhibiting HIF-1α-mediated reprogramming of glycometabolism and macrophage proliferation.

The inflammatory responses involving infiltration and activation of liver macrophages play a vital role in acute liver failure (ALF). In the liver of ALF mice, cannabinoid receptor 2 (CB2R) is significantly upregulated on macrophages, while CB2R agonist GW405833 (GW) could protect against cell death in acute liver damage. In this study, we investigated the molecular mechanisms underlying the protective effects of GW against ALF in vivo and in vitro from a perspective of macrophage glycometabolism. Mice were pretreated with GW (10 mg/kg, i.p.), then were injected with D-GalN (750 mg/kg, i.p.) and LPS (10 mg/kg, i.p.) to induce ALF. We verified the protective effects of GW pretreatment in ALF mice. Furthermore, GW pretreatment significantly reduced liver macrophage infiltration and M1 polarization, and inhibited the release of inflammatory factors TNF-α and IL-1ß in ALF mice. These protective effects were eliminated by CB2R antagonist SR144528 or in CB2R-/- ALF mice. We used LPS-stimulated RAW264.7 cells as an in vitro M1 macrophage-centered model of inflammatory response, and demonstrated that pretreatment with GW (10 µM) significantly reduced glucose metabolism by inhibiting glycolysis, which inhibited LPS-induced macrophage proliferation and inflammatory cytokines release. We verified these results in a stable CB2R-/- RAW264.7 cell line. Moreover, we found that GW significantly inhibited the expression of hypoxia inducible factor 1α (HIF-1α). Using a stable HIF-1α-/- RAW264.7 cell line, we confirmed that GW reduced the release of inflammatory cytokines from macrophages and inhibited glycolysis by downregulating HIF-1α expression. In conclusion, activation of CB2Rs inhibits the proliferation of hepatic macrophages and release of inflammatory factors in ALF mice through downregulating HIF-1α to inhibit glycolysis.

Genotypic and phenotypic spectrum of infantile liver failure due to pathogenic TRMU variants.

PURPOSE: This study aimed to define the genotypic and phenotypic spectrum of reversible acute liver failure (ALF) of infancy resulting from biallelic pathogenic TRMU variants and determine the role of cysteine supplementation in its treatment. METHODS: Individuals with biallelic (likely) pathogenic variants in TRMU were studied within an international retrospective collection of de-identified patient data. RESULTS: In 62 individuals, including 30 previously unreported cases, we described 47 (likely) pathogenic TRMU variants, of which 17 were novel, and 1 intragenic deletion. Of these 62 individuals, 42 were alive at a median age of 6.8 (0.6-22) years after a median follow-up of 3.6 (0.1-22) years. The most frequent finding, occurring in all but 2 individuals, was liver involvement. ALF occurred only in the first year of life and was reported in 43 of 62 individuals; 11 of whom received liver transplantation. Loss-of-function TRMU variants were associated with poor survival. Supplementation with at least 1 cysteine source, typically N-acetylcysteine, improved survival significantly. Neurodevelopmental delay was observed in 11 individuals and persisted in 4 of the survivors, but we were unable to determine whether this was a primary or a secondary consequence of TRMU deficiency. CONCLUSION: In most patients, TRMU-associated ALF was a transient, reversible disease and cysteine supplementation improved survival.

Use of N-Acetylcysteine for Clozapine-Induced Acute Liver Injury: A Case Report and Literature Review.

Purpose: To report a case of clozapine-induced hepatotoxicity managed with intravenous (IV) N-acetylcysteine (NAC) and summarize the available literature. Summary: A 46-year-old woman with history of bipolar disorder with psychotic features presented to the intensive care unit with asterixis and elevations in liver enzymes. The patient had been initiated on risperidone, clozapine, and lithium approximately 1 month prior to admission. After ruling out other possible non-drug etiologies, clozapine was suspected as the likeliest cause of the acute liver injury. Her acute liver injury was managed with the discontinuation of all antipsychotics, administration of IV NAC, and other standard of care supportive measures. Conclusion: Although clozapine has been associated with hepatitis and acute liver failure, there are no reports of NAC used in the management of clozapine-induced hepatotoxicity. NAC was used in our patient after considering the potential benefit and limited adverse effects. The role of NAC in non-acetaminophen-induced acute liver failure remains promising, but more research is warranted.

Prospective Application of Tannic Acid in Acetaminophen (APAP)-Induced Acute Liver Failure.

This study investigated the effect of tannic acid (TA), a natural plant-derived polyphenol, on hepatocyte viability and function, focusing on both hepatoprotective and hepatocurative aspects within liver failure models. In an in vitro prevention model, the TA-containing group exhibited 1.5-fold and 59-fold higher relative cell viability and albumin synthesis, respectively, in injured mature hepatocytes (MHs) and 1.14-fold and 1.10-fold higher values in injured small hepatocytes (SHs), compared with the TA-free group. In the in vitro curative model, the TA-containing group exhibited 3.25-fold and 113-fold higher relative cell viability and albumin synthesis, respectively, in injured MHs and 0.36-fold and 3.55-fold higher values in injured SHs, compared with the TA-free group. In the in vivo disease model, the administration of 300 µL of 1 µg/mL TA significantly mitigated acute liver failure damage and post-APAP toxicity in mice. This was evident in serum analysis, where the levels of alanine transaminase, aspartate aminotransferase, and total bilirubin notably decreased, in agreement with histological observations. The study findings reveal that TA can enhance hepatic function at specific additive concentrations. Furthermore, even when injured by APAP, hepatocytes could revert to their preinjury state after additional TA supplementation. Additionally, pretreating hepatocytes with TA can alleviate subsequent damage. Thus, TA holds clinical potential in the treatment of APAP-induced liver failure.

Therapeutic Management of Idiosyncratic Drug-Induced Liver Injury and Acetaminophen Hepatotoxicity in the Paediatric Population: A Systematic Review.

INTRODUCTION: Drug-induced liver injury (DILI) is a rare but serious adverse event that can progress to acute liver failure (ALF). The evidence for treatment of DILI in children is scarce. OBJECTIVE: We aimed to comprehensively review the available literature on the therapies for both acetaminophen overdose (APAP) and idiosyncratic DILI in the paediatric population. METHODS: We included original articles conducted in a paediatric population (< 18 years) in which a therapeutic intervention was described to manage APAP or idiosyncratic DILI. Findings were summarized based on age groups (preterm newborn neonates, term and post-term neonates, infants, children and adolescents). RESULTS: Overall, 25 publications (fifteen case reports, six case series and four retrospective cohort studies) were included, including a total of 140 paediatric DILI cases, from preterm newborn neonates to adolescents. N-acetylcysteine was used to treat 19 APAP cases. N-acetylcysteine (n = 14), ursodeoxycholic acid (n = 3), corticosteroids (n = 31), carnitine (n = 16) and the combination of glycyrrhizin, reduced glutathione, polyene phosphatidylcholine and S-adenosylmethionine (n = 31) were the therapeutic options for treating idiosyncratic DILI. The molecular adsorbent recirculating system was used in the management of either APAP (n = 4) or idiosyncratic DILI (n = 2), while 20 paediatric ALF cases received continuous renal replacement therapy. CONCLUSIONS: This systematic review identified DILI in the paediatric population who have received specific treatment. These interventions appear to be mainly extrapolated from low-quality evidence from the adult population. Thus, there is a need for high-quality studies to test the efficacy of known and novel therapies to treat DILI specifically addressed to the paediatric population. PROSPERO registration number CRD42021214702.