Acute Liver Failure Mice Research Articles

Carfilzomib Mitigates Lipopolysaccharide/D-Galactosamine/Dimethylsulfoxide-Induced Acute Liver Failure in Mice.

Acute liver failure (ALF) is a disease accompanied by severe liver inflammation. No effective therapy is available yet apart from liver transplantation; therefore, developing novel treatments for ALF is urgently required. Inflammatory mediators released by NF-кB activation play an essential role in ALF. Proteasome inhibitors have many medical uses, such as reducing inflammation and NF-кB inhibition, which are believed to account for most of their repurposing effects. This study was undertaken to explore the possible protective effects and the underlying mechanisms of carfilzomib, a proteasome inhibitor, in a mouse model of ALF induced by lipopolysaccharide/D-galactosamine/dimethylsulfoxide (LPS/GalN/DMSO). Carfilzomib dose-dependently protected mice from LPS/GalN/DMSO-induced liver injury, as indicated by the decrease in serum alanine aminotransferase and aspartate aminotransferase levels. LPS/GalN/DMSO increased TNF-α, NF-кB, lipid peroxidation, NO, iNOS, cyclooxygenase-II, myeloperoxidase, and caspase-3 levels. Carfilzomib administration mitigated LPS/GalN/DMSO-induced liver damage by decreasing the elevated levels of TNF-α, NF-кB, lipid peroxidation, nitric oxide, iNOS, cyclooxygenase-II, myeloperoxidase, caspase-3, and histopathological changes. A restored glutathione level was also observed in the carfilzomib-treated LPS/GalN/DMSO mice. Our results demonstrate that carfilzomib protects against LPS/GalN/DMSO-induced ALF by inhibiting NF-кB, decreasing inflammatory mediators, oxidative/nitrosative stress, neutrophil recruitment, and apoptosis, suggesting that carfilzomib may be a potential therapeutic agent for ALF.

Protective effect of recombinant Schistosoma japonicum cystatin against acute kidney injury associated with acute liver failure in mice

To evaluate the protective effect of recombinant Schistosoma japonicum cystatin (rSj-Cys) against acute kidney injury induced by acute liver failure and unravel the underlying mechanism, so as to provide insights into the clinical therapy of acute kidney injury. Twenty-four male C57BL/6J mice at ages of 6 to 8 weeks were randomly divided into the normal control group, rSj-Cys control group, lipopolysaccharide (LPS)/D-galactosamine (D-GaIN) model group and LPS/D-GaIN + rSj-Cys treatment group, of 6 mice each group. Mice in the LPS/D-GaIN group and LPS/D-GaIN + rSj-Cys group were intraperitoneally injected with LPS (10 μg/kg) and D-GaIN (700 mg/kg), and mice in the LPS/D-GaIN + rSj-Cys group were additionally administered with rSj-Cys (1.25 mg/kg) by intraperitoneal injection 30 min post-modeling, while mice in the rSj-Cys group were intraperitoneally injected with rSj-Cys (1.25 mg/kg), and mice in the normal control group were injected with the normal volume of PBS. All mice were sacrificed 6 h post-modeling, and mouse serum and kidney samples were collected. Serum creatinine (Cr) and urea nitrogen (BUN) levels were measured, and the pathological changes of mouse kidney specimens were examined using hematoxylin-eosin (HE) staining. Serum tumor necrosis factor (TNF)-α and interleukin (IL)-6 levels were detected using enzyme-linked immunosorbent assay (ELISA), and the expression of inflammatory factors and pyroptosis-related proteins was quantified in mouse kidney specimens using immunohistochemistry. In addition, the expression of pyroptosis-related proteins and nuclear factor-kappa B (NF-κB) signaling pathway-associated proteins was determined in mouse kidney specimens using Western blotting assay. HE staining showed no remarkable abnormality in the mouse kidney structure in the normal control group and the rSj-Cys control group, and renal tubular injury was found in LPS/D-GaIN group, while the renal tubular injury was alleviated in LPS/D-GaIN+rSj-Cys treatment group. There were significant differences in serum levels of Cr (F = 46.33, P < 0.001), BUN (F = 128.60, P < 0.001), TNF-α (F = 102.00, P < 0.001) and IL-6 (F = 202.10, P < 0.001) among the four groups, and lower serum Cr [(85.35 ± 32.05) μmol/L], BUN [(11.90 ± 2.76) mmol/L], TNF-α [(158.27 ± 15.83) pg/mL] and IL-6 levels [(56.72 ± 4.37) pg/mL] were detected in the in LPS/D-GaIN + rSj-Cys group than in the LPS/D-GaIN group (all P values < 0.01). Immunohistochemical staining detected significant differences in TNF-α (F = 24.16, P < 0.001) and IL-10 (F = 15.07, P < 0.01) expression among the four groups, and lower TNF-α [(106.50 ± 16.57)%] and higher IL-10 expression [(91.83 ± 5.23)%] was detected in the LPS/D-GaIN + rSj-Cys group than in the LPS/D-GaIN group (both P values < 0.01). Western blotting and immunohistochemistry detected significant differences in the protein expression of pyroptosis-related proteins NOD-like receptor thermal protein domain associated protein 3 (NLRP3) (F = 24.57 and 30.72, both P values < 0.001), IL-1β (F = 19.24 and 22.59, both P values < 0.001) and IL-18 (F = 16.60 and 19.30, both P values < 0.001) in kidney samples among the four groups, and lower NLRP3, IL-1β and IL-18 expression was quantified in the LPS/D-GaIN + rSj-Cys treatment group than in the LPS/D-GaIN group (P values < 0.05). In addition, there were significant differences in the protein expression of NF-κB signaling pathway-associated proteins p-NF-κB p-P65/NF-κB p65 (F = 71.88, P < 0.001), Toll-like receptor (TLR)-4 (F = 45.49, P < 0.001) and p-IκB/IκB (F = 60.87, P < 0.001) in mouse kidney samples among the four groups, and lower expression of three NF-κB signaling pathway-associated proteins was determined in the LPS/D-GaIN + rSj-Cys treatment group than in the LPS/D-GaIN group (all P values < 0.01). rSj-Cys may present a protective effect against acute kidney injury caused by acute liver failure through inhibiting inflammation and pyroptosis and downregulating the NF-κB signaling pathway.

Essential oil extracted from Quzhou Aurantii Fructus prevents acute liver failure through inhibiting lipopolysaccharide-mediated inflammatory response

Quzhou Aurantii Fructus (QAF) has a long history as a folk medicine and food for the treatment of liver diseases. While our earlier study provided evidence of hepatoprotective properties contained within the flavonoids and limonins constituents in QAF, the potential preventative effects afforded by essential oil components present within QAF remains enigmatic. In this study, we prepared Quzhou Aurantii Fructus essential oil (QAFEO) and confirmed its anti-inflammatory effects on liver inflammation through experimentation on lipopolysaccharide and D-galactosamine (LPS/D-GalN) induced acute liver failure (ALF) mouse models. Using RNA-sequence (RNA-seq) analysis, we found that QAFEO prevented ALF by systematically blunting the pathways involved in response to LPS and toll-like receptor signaling pathways. QAFEO effectively suppressed the phosphorylation of tank-binding kinase 1 (TBK1), TGF-beta activated kinase 1 (TAK1), interferon regulatory factor 3 (IRF3), and the activation of mitogen activated kinase-like protein (MAPK) and nuclear factor-kappa B (NF-κB) pathways in vivo and in vitro. Importantly, QAFEO substantially reduced myeloid differentiation primary response gene 88 (MyD88)- toll-like receptor 4 (TLR4) interaction levels. Moreover, 8 compounds from QAFEO could directly bind to REAL, TAK1, MyD88, TBK1, and IRF3. Taken together, the results of our study support the notion that QAFEO exerts a hepatoprotective effect through inhibiting LPS-mediated inflammatory response.Graphical abstract

MicroRNA-181a-5p alleviates acute liver failure in mice by inhibiting HMGB1.

MicroRNAs (miRNAs) control liver diseases, but the role of microRNA-181a-5p in acute liver failure (ALF) is unclear. In this study, the ALF model was generated by injection of D-galactosamine (D-GalN) and lipopolysaccharide (LPS). The levels of miRNAs were assessed by microarray and qRT-PCR. The expression of caspase 3 was detected as the marker of cell apoptosis in ALF by immunohistochemistry and western blot. The targeting of microRNA-181a-5p on the high mobility group box 1 (HMGB1) was verified by dual luciferase assay. The impact of microRNA-181a-5p and HMGB1 was explored by flow cytometry. Results showed that microRNA-181a-5p was significantly down-regulated by D-GalN/LPS in vivo and in vitro, while the level of HMGB1 was up-regulated after the challenge. Furthermore, microRNA-181a-5p overexpression attenuated cell apoptosis in D-GalN/TNF-treated BNLCL2 cells. MicroRNA-181a-5p could directly target HMGB1 mRNA and repress its expressions, in further HMGB1 is involved in microRNA-181a-5p effect on cell apoptosis of ALF. In conclusion, these findings demonstrate that microRNA-181a-5p regulates hepatocyte apoptosis via HMGB1 in the development of ALF, which may provide potential therapeutic targets for ALF. However, the precise underlying mechanism that connects microRNA-181a-5p and HMGB1 remains to be explored.

Garlic-derived exosome-like nanovesicles as a hepatoprotective agent alleviating acute liver failure by inhibiting CCR2/CCR5 signaling and inflammation

Acute liver failure (ALF) is a life-threatening clinical syndrome mostly induced by viral infections or drug abuse. As a novel therapeutic adjuvant or delivery vehicle, plant-derived exosome-like nanovesicles (PELNVs) have been extensively studied in recent years. This study aimed to develop garlic-derived exosome-like nanovesicles (GaELNVs) in order to ameliorate liver injury induced by LPS/D-GalN in mice, inhibit inflammatory eruption and reduce inflammatory cells infiltration. The results showed that treatment with GaELNVs improved liver pathology and reduced the levels of soluble inflammatory mediators IL-6, IL-1β and TNF-α in the serum of ALF mice. GaELNVs reversed the upregulation of Cleaved Caspase-9, Cleaved Caspase-3, p53 and Bax expression and decreased Bcl2 activation caused by D-GalN/LPS, and inhibited NF-κB p65 expression and translocation to the nucleus. Meanwhile, treatment with GaELNVs resulted significant reduction in NLRP3 activation and Caspase-1 maturation, as well as decrease in the release of the inflammatory mediator IL-18. Additionally, an upregulation of the expression of proteins related to energy metabolism and autophagy occurrence including Foxo3a, Sirt1, and LC3-II was detected in the liver. Oral administration of GaELNVs also led to significant alteration in the expression of F4/80 and CD11b in the liver. Furthermore, the detection of chemokines in mouse liver tissue revealed that GaELNVs exhibited minimal reduction in the expression of CCL2, CCL3, CCL5 and CCL8. The decreased expression of CCR2 and CCR5 in the liver suggests that GaELNVs have the ability to decrease the recruitment of monocytes from the circulation to the liver. A reduction in the infiltration of F4/80loCD11bhi monocyte-derived macrophages into the liver was also observed. This study provides novel evidence that GaELNVs can ameliorate inflammatory eruptions and hinder the migration of circulating monocytes to the liver, as well as decrease macrophage infiltration by inhibiting CCR2/CCR5 signaling. Consequently, GaELNVs hold promise as a novel therapeutic agent for clinical management of liver disease.

HIF-1α inhibition in macrophages preserves acute liver failure by reducing IL-1β production.

The development of acute liver failure (ALF) is dependent on its local inducer. Inflammation is a high-frequency and critical factor that accelerates hepatocyte death and liver failure. In response to injury stress, the expression of the transcription factor hypoxia-inducible factor-1α (HIF-1α) in macrophages is promoted by both oxygen-dependent and oxygen-independent mechanisms, thus promoting the expression and secretion of the cytokine interleukin-1β (IL-1β). IL-1β further induces hepatocyte apoptosis or necrosis by signaling through the receptor (IL-1R) on hepatocyte. HIF-1α knockout in macrophages or IL-1R knockout in hepatocytes protects against liver failure. However, whether HIF-1α inhibition in macrophages has a protective role in ALF is unclear. In this study, we revealed that the small molecule HIF-1α inhibitor PX-478 inhibits the expression and secretion of IL-1β, but not tumor necrosis factor α (TNFα), in bone marrow-derived macrophages (BMDMs). PX-478 pretreatment alleviates liver injury in LPS/D-GalN-induced ALF mice by decreasing the hepatic inflammatory response. In addition, preventive or therapeutic administration of PX-478 combined with TNFα neutralizing antibody markedly improved LPS/D-GalN-induced ALF. Taken together, our data suggest that PX-478 administration leads to HIF-1α inhibition and decreased IL-1β secretion in macrophages, which represents a promising therapeutic strategy for inflammation-induced ALF.

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-1β 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-1β 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.

Single-cell transcriptomics reveals intestinal cell heterogeneity and identifies Ep300 as a potential therapeutic target in mice with acute liver failure

Acute liver failure (ALF) is a severe life-threatening disease associated with the disorder of the gut-liver axis. However, the cellular characteristics of ALF in the gut and related therapeutic targets remain unexplored. Here, we utilized the D-GALN/LPS (D/L)-induced ALF model to characterize 33,216 single-cell transcriptomes and define a mouse ALF intestinal cellular atlas. We found that unique, previously uncharacterized intestinal immune cells, including T cells, B cells, macrophages, and neutrophils, are responsive to ALF, and we identified the transcriptional profiles of these subsets during ALF. We also delineated the heterogeneity of intestinal epithelial cells (IECs) and found that ALF-induced cell cycle arrest in intestinal stem cells and activated specific enterocyte and goblet cell clusters. Notably, the most significantly altered IECs, including enterocytes, intestinal stem cells and goblet cells, had similar activation patterns closely associated with inflammation from intestinal immune activation. Furthermore, our results unveiled a common Ep300-dependent transcriptional program that coordinates IEC activation during ALF, which was confirmed to be universal in different ALF models. Pharmacological inhibition of Ep300 with an inhibitor (SGC-CBP30) inhibited this cell-specific program, confirming that Ep300 is an effective target for alleviating ALF. Mechanistically, Ep300 inhibition restrained inflammation and oxidative stress in the dysregulated cluster of IECs through the P38-JNK pathway and corrected intestinal ecology by regulating intestinal microbial composition and metabolism, thereby protecting IECs and attenuating ALF. These findings confirm that Ep300 is a novel therapeutic target in ALF and pave the way for future pathophysiological studies on ALF.

A simple and efficient strategy for cell-based and cell-free-based therapies in acute liver failure: hUCMSCs bioartificial liver.

Acute liver failure (ALF) is a life-threatening condition. Cell-based and cell-free-based therapies have proven to be effective in treating ALF; however, their clinical application is limited by cell tumorigenicity and extracellular vesicle (EV) isolation in large doses. Here, we explored the effectiveness and mechanism of umbilical cord mesenchymal stem cells (hUCMSCs)-based bioartificial liver (hUCMSC-BAL), which is a simple and efficient strategy for ALF. D-galactosamine-based pig and mouse ALF models were used to explore the effectiveness of hUCMSC-BAL and hUCMSC-sEV therapies. Furthermore, high-throughput sequencing, miRNA transcriptome analysis, and western blot were performed to clarify whether the miR-139-5p/PDE4D axis plays a critical role in the ALF model in vivo and in vitro. hUCMSC-BAL significantly reduced inflammatory responses and cell apoptosis. hUCMSC-sEV significantly improved liver function in ALF mice and enhanced the regeneration of liver cells. Furthermore, hUCMSC-sEV miRNA transcriptome analysis showed that miR-139-5p had the highest expression and that PDE4D was one of its main target genes. The sEV miR-139-5p/PDE4D axis played a role in the treatment of ALF by inhibiting cell apoptosis. Our data indicate that hUCMSC-BAL can inhibit cytokine storms and cell apoptosis through the sEV miR-139-5p/PDE4D axis. Therefore, we propose hUCMSC-BAL as a therapeutic strategy for patients with early ALF.

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

AimsAcute 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. MethodsALF 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. ResultsAKF-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. ConclusionsIn 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.

Stem cell-derived hepatocyte therapy using versatile biomimetic nanozyme incorporated nanofiber-reinforced decellularized extracellular matrix hydrogels for the treatment of acute liver failure

Reactive oxygen species (ROS)-associated oxidative stress, inflammation storm, and massive hepatocyte necrosis are the typical manifestations of acute liver failure (ALF), therefore specific therapeutic interventions are essential for the devastating disease. Here, we developed a platform consisting of versatile biomimetic copper oxide nanozymes (Cu NZs)-loaded PLGA nanofibers (Cu NZs@PLGA nanofibers) and decellularized extracellular matrix (dECM) hydrogels for delivery of human adipose-derived mesenchymal stem/stromal cells-derived hepatocyte-like cells (hADMSCs-derived HLCs) (HLCs/Cu NZs@fiber/dECM). Cu NZs@PLGA nanofibers could conspicuously scavenge excessive ROS at the early stage of ALF, and reduce the massive accumulation of pro-inflammatory cytokines, herein efficiently preventing the deterioration of hepatocytes necrosis. Moreover, Cu NZs@PLGA nanofibers also exhibited a cytoprotection effect on the transplanted HLCs. Meanwhile, HLCs with hepatic-specific biofunctions and anti-inflammatory activity acted as a promising alternative cell source for ALF therapy. The dECM hydrogels further provided the desirable 3D environment and favorably improved the hepatic functions of HLCs. In addition, the pro-angiogenesis activity of Cu NZs@PLGA nanofibers also facilitated the integration of the whole implant with the host liver. Hence, HLCs/Cu NZs@fiber/dECM performed excellent synergistic therapeutic efficacy on ALF mice. This strategy using Cu NZs@PLGA nanofiber-reinforced dECM hydrogels for HLCs in situ delivery is a promising approach for ALF therapy and shows great potential for clinical translation.

Retracted] Inhibition of RKIP aggravates thioacetamide‑induced acute liver failure in mice.

[This retracts the article DOI: 10.3892/etm.2018.6542.].

Identification of key immune-related genes associated with LPS/D-GalN-induced acute liver failure in mice based on transcriptome sequencing.

The aim of this study was to identify key immune-related genes in acute liver failure (ALF) by constructing an ALF mouse model for transcriptome sequencing. The C57BL/6 mouse with ALF model was induced by lipopolysaccharide (LPS)/ D-galactosamine (D-GalN). After successful modelling, the liver tissues of all mice were obtained for transcriptome sequencing. The key immune-related genes in mice with ALF were identified by differential expression analysis, immune infiltration analysis, weighted gene co-expression network analysis (WGCNA), enrichment analysis, and protein-protein interaction (PPI) analysis. An LPS/D-GalN-induced ALF mouse model was successfully constructed, and transcriptome sequencing was performed. Significant differences in the proportions of monocytes, macrophages M0, macrophages M1 and neutrophils were shown by immune infiltration analysis, and 5255 genes highly associated with these four immune cells were identified by WGCNA. These immune genes were found to be significantly enriched in the TNF signalling pathway by enrichment analysis. Finally, PPI analysis was performed on genes enriched in this pathway and three key genes (CXCL1, CXCL10 and IL1B) were screened out and revealed to be significantly upregulated in ALF. Key immune-related genes in ALF were identified in this study, which may provide not only potential therapeutic targets for treating ALF and improving its prognosis, but also a reliable scientific basis for the immunotherapy of the disease.

Effect of astragaloside on expression of smac, cytochrome C and caspase-3 in hepatic tissue of acute hepatic failure induced by D-Gal NLPS

This study assessed astragaloside IV’s effect on liver Smac, Cytochrome C (Cyt-C) and Caspase-3 expression in acute liver failure in mice. Mice were randomly assigned into normal group, model group, model+astragaloside (1%) group and model+astragaloside (5%) group. Mice were given by gavage of astragaloside (50 mg/kg/d, 250 mg/kg/d) for 2 d before making the model in model + astragaloside group and model+astragaloside group. Equal dose of normal saline was administrated to the other groups. Except for the normal group, mice in the other groups were intraperitoneally injected with D-GalN/LPS for 48 h. The mice were at the end killed after the final intraperitoneal injection for 2 hours. Hepatic apoptosis and expressions of hepatic Smac, Cyt-C and caspase-3 were then analyzed. Mice exhibited less hepatocyte apoptosis and lower content of hepatic Cyt-C expression in both the model+astragaloside and model+astragaloside groups (P &lt;0.01). D-GalN/LPS significantly enhanced Caspase-3 and Smac mRNA. Moreover, astragaloside suppressed the activity of Caspase-3 and decreased hepatic Smac mRNA expression in mice (P &lt;0.01). Astragaloside IV can reduce the content of Cyt-C and down-regulate the expression of Smac and caspase-3, thereby protecting acute liver failure.

VX-765 inhibits pyroptosis and reduces inflammation to prevent acute liver failure by upregulating PPARα expression

Introduction and ObjectivesAs a fatal clinical syndrome, acute liver failure (ALF) is characterized by overwhelming liver inflammation and hepatic cell death. Finding new therapeutic methods has been a challenge in ALF research. VX-765 is a known pyroptosis inhibitor and has been reported to prevent damage in a variety of diseases by reducing inflammation. However, the role of VX-765 in ALF is still unclear. Materials and MethodsALF model mice were treated with D-galactosamine (D-GalN) and lipopolysaccharide (LPS). LO2 cells were stimulated with LPS. Thirty subjects were enrolled in clinical experiments. The levels of inflammatory cytokines, pyroptosis-associated proteins and peroxisome proliferator-activated receptor α (PPARα) were detected using quantitative reverse transcription-polymerase chain reaction (qRT‒PCR), western blotting and immunohistochemistry. An automatic biochemical analyzer was used to determine the serum aminotransferase enzyme levels. Hematoxylin and eosin (HE) staining was used to observe the pathological features of the liver. ResultsWith the progression of ALF, the expression levels of interleukin (IL) -1β, IL-18, caspase-1, and serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were increased. VX-765 could reduce the mortality rate of ALF mice, relieve liver pathological damage, and reduce inflammatory responses to protect against ALF. Further experiments showed that VX-765 could protect against ALF through PPARα, and this protective effect against ALF was reduced in the context of PPARα inhibition. ConclusionsAs ALF progresses, inflammatory responses and pyroptosis deteriorate gradually. VX-765 can inhibit pyroptosis and reduce inflammatory responses to protect against ALF by upregulating PPARα expression, thus providing a possible therapeutic strategy for ALF.

Stress granules inhibit endoplasmic reticulum stress-mediated apoptosis during hypoxia-induced injury in acute liver failure.

Stress granules (SGs) could be formed under different stimulation to inhibit cell injury. To investigate whether SGs could protect hepatocytes from hypoxia-induced damage during acute liver failure (ALF) by reducing endoplasmic reticulum stress (ERS) mediated apoptosis. The agonist of SGs, arsenite (Ars) was used to intervene hypoxia-induced hepatocyte injury cellular model and ALF mice models. Further, the siRNA of activating transcription factor 4 (ATF4) and SGs inhibitor anisomycin was then used to intervene in cell models. With the increase of hypoxia time from 4 h to 12 h, the levels of HIF-1α, ERS and apoptosis gradually increased, and the expression of SGs marker G3BP1 and TIA-1 was increased and then decreased. Compared with the hypoxia cell model group and ALF mice model, the levels of HIF-1α, apoptosis and ERS were increased in the Ars intervention group. After siRNA-ATF4 intervention, the level of SGs in cells increased, and the levels of HIF-1α, ERS and apoptosis decreased. Compared with the siRNA-ATF4 group, the levels of G3BP1 in the siRNA-ATF4+anisomycin group were decreased, and the levels of HIF-1α, ERS and apoptosis were increased. Moreover, compared with the ALF group, the degree of liver injury and liver function, the levels of HIF-1α, ERS and apoptosis in the Ars intervention group were decreased, the level of SGs was increased. SGs could protect hepatocytes from hypoxia-induced damage during ALF by reducing ERS-mediated apoptosis.

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.

Exploration and verification of COVID-19-related hub genes in liver physiological and pathological regeneration.

Objectives An acute injury is often accompanied by tissue regeneration. In this process, epithelial cells show a tendency of cell proliferation under the induction of injury stress, inflammatory factors, and other factors, accompanied by a temporary decline of cellular function. Regulating this regenerative process and avoiding chronic injury is a concern of regenerative medicine. The severe coronavirus disease 2019 (COVID-19) has posed a significant threat to people's health caused by the coronavirus. Acute liver failure (ALF) is a clinical syndrome resulting from rapid liver dysfunction with a fatal outcome. We hope to analyze the two diseases together to find a way for acute failure treatment. Methods COVID-19 dataset (GSE180226) and ALF dataset (GSE38941) were downloaded from the Gene Expression Omnibus (GEO) database, and the "Deseq2" package and "limma" package were used to identify differentially expressed genes (DEGs). Common DEGs were used for hub genes exploration, Protein-Protein Interaction (PPI) network construction, Gene Ontology (GO) functional enrichment, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment. The real-time reverse transcriptase-polymerase chain reaction (RT-qPCR) was used to verify the role of hub genes in liver regeneration during in vitro expansion of liver cells and a CCl4-induced ALF mice model. Results: The common gene analysis of the COVID-19 and ALF databases revealed 15 hub genes from 418 common DEGs. These hub genes, including CDC20, were related to cell proliferation and mitosis regulation, reflecting the consistent tissue regeneration change after the injury. Furthermore, hub genes were verified in vitro expansion of liver cells and in vivo ALF model. On this basis, the potential therapeutic small molecule of ALF was found by targeting the hub gene CDC20. Conclusion We have identified hub genes for epithelial cell regeneration under acute injury conditions and explored a new small molecule Apcin for liver function maintenance and ALF treatment. These findings may provide new approaches and ideas for treating COVID-19 patients with ALF.

Upregulated microRNA-450b-5p represses the development of acute liver failure via modulation of liver function, inflammatory response, and hepatocyte apoptosis.

It has been evidenced that microRNAs (miRs) exert crucial effects on acute liver failure (ALF), while the detailed function of miR-450b-5p in ALF progression remained obscure. The purpose of this research was to unravel the regulatory mechanism of miR-450b-5p in ALF via modulating Mouse Double Minute 2 protein (MDM2). ALF was induced in mice by intraperitoneal injection of d-galactosamine ( d-GalN) and lipopolysaccharide (LPS). Adenoviruses containing overexpressed miR-450b-5p, MDM2 shRNA, and overexpressed MDM2 sequences were utilized to manipulate miR-450b-5p and MDM2 expression in the liver before the mice were treated with d-GalN/LPS-induced ALF. Subsequently, miR-450b-5p and MDM2 expression levels in liver tissues of ALF mice were examined. Serum biochemical parameters of liver function were tested, serum inflammatory factors were assessed, and the histopathological changes and hepatocyte apoptosis in liver tissues were observed. The relation between miR-450b-5p and MDM2 was verified. In ALF mice, miR-450b-5p was low-expressed while MDM2 was high-expressed. The upregulation of miR-450b-5p or downregulation of MDM2 could alleviate liver function, mitigate the serum inflammatory response and pathological changes in liver tissues, as well as inhibit the apoptosis of hepatocytes. MiR-450b-5p targeted MDM2. MDM2 overexpression reversed the repressive effects of elevated miR-450b-5p on ALF. The upregulated miR-450b-5p blocks the progression of ALF via targeting MDM2. This study contributes to affording novel therapeutic targets for ALF treatment.

Cathelicidin promotes liver repair after acetaminophen-induced liver injury in mice

Acetaminophen (APAP)-induced acute liver injury (AILI) is a leading cause of acute liver failure (ALF). N-acetylcysteine (NAC) is only effective within 24h after APAP intoxication, raising an urgent need for alternative approaches to treat this disease. This study aimed to test whether cathelicidin (Camp), which is a protective factor in chronic liver diseases, protects mice against APAP-induced liver injury and ALF. A clinically relevant AILI model and an APAP-induced ALF model were generated in mice. Genetic and pharmacological approaches were used to interfere with the levels of cathelicidin invivo. An increase in hepatic pro-CRAMP/CRAMP (the precursor and mature forms of mouse cathelicidin) was observed in APAP-intoxicated mice. Upregulated cathelicidin was derived from liver-infiltrating neutrophils. Compared with wild-type littermates, Camp knockout had no effect on hepatic injury but dampened hepatic repair in AILI and reduced survival in APAP-induced ALF. CRAMP administration reversed impaired liver recovery observed in APAP-challenged Camp knockout mice. Delayed CRAMP, CRAMP(1-39) (the extended form of CRAMP), or LL-37 (the mature form of human cathelicidin) treatment exhibited a therapeutic benefit for AILI. Co-treatment of cathelicidin and NAC in AILI displayed a stronger hepatoprotective effect than NAC alone. A similar additive effect of CRAMP(1-39)/LL-37 and NAC was observed in APAP-induced ALF. The pro-reparative role of cathelicidin in the APAP-damaged liver was attributed to an accelerated resolution of inflammation at the onset of liver repair, possibly through enhanced neutrophil phagocytosis of necrotic cell debris in an autocrine manner. Cathelicidin reduces APAP-induced liver injury and ALF in mice by promoting liver recovery via facilitating inflammation resolution, suggesting a therapeutic potential for late-presenting patients with AILI with or without ALF. Acetaminophen-induced acute liver injury is a leading cause of acute liver failure. The efficacy of N-acetylcysteine, the only clinically approved drug against acetaminophen-induced acute liver injury, is significantly reduced for late-presenting patients. We found that cathelicidin exhibits a great therapeutic potential in mice with acetaminophen-induced liver injury or acute liver failure, which makes up for the limitation of N-acetylcysteine therapy by specifically promoting liver repair after acetaminophen intoxication. The pro-reparative role of cathelicidin, as a key effector molecule of neutrophils, in the APAP-injured liver is attributed to an accelerated resolution of inflammation at the onset of liver repair, possibly through enhanced phagocytic function of neutrophils in an autocrine manner.