D-galactosamine/lipopolysaccharide Research Articles

MiRNA‑21 promotes the progression of acute liver failure via the KLF6/autophagy/IL‑23 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 miR‑21 was analyzed in patients with ALF and healthy controls. In addition, miR‑21 antagomir was injected via the tail vein into C57BL/6 mice, and lipopolysaccharide/D‑galactosamine (LPS/GalN) was injected into mice after 48 h. The expression levels of miR‑21, Krüppel‑like‑factor‑6 (KLF6), autophagy‑related proteins and interleukin (IL)‑23, and hepatic pathology were then assessed in the liver tissue. Furthermore, THP‑1‑derived macrophages were transfected with a miRNA negative control, miR‑21 inhibitor, miR‑21 mimics or KLF6 overexpression plasmid, followed by treatment with or without rapamycin, and the expression levels of miR‑21, KLF6, autophagy‑related proteins and IL‑23 were evaluated. The results revealed that baseline serum miR‑21 levels were significantly upregulated in patients with ALF. In addition, LPS/GalN‑induced ALF was attenuated in the antagomir‑21 mouse group. KLF6 was identified as a target of miR‑21‑5p with one putative seed match site identified by TargetScan. A subsequent luciferase activity assay demonstrated a direct interaction between miR‑21‑5p and the 3'‑UTR of KLF6 mRNA. Further experiments suggested that miR‑21 promoted the expression of IL‑23 via inhibiting KLF6, which regulated autophagy. In conclusion, in the present study, baseline serum miR‑21 levels were highly upregulated in patients with ALF, antagomir‑21 attenuated LPS/GalN‑induced ALF in a mouse model, and miR‑21 could promote the expression of IL‑23 via inhibiting KLF6.

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.

Janus kinase inhibitor Tofacitinib alleviated acute hepatitis induced by lipopolysaccharide/D-galactosamine in mice.

The Janus kinase (JAK) is a crucial intracellular signaling hub for numerous cytokines, which is extensively involved in the activation of inflammatory cascade and the induction of inflammatory injury. JAK inhibition provides protective effects in several inflammation-based disorders, but the potential effects of JAK inhibitor in inflammation-based acute hepatitis remain to be investigated. Acute hepatitis is induced by Lipopolysaccharide/D-galactosamine (LPS/D-Gal) in mice with or without the JAK inhibitor Tofacitinib administration. The degree of liver injury, the production of pro-inflammatory cytokines and induction of hepatocytes apoptosis were determined. The results indicated that treatment with Tofacitinib decreased the levels of aminotransferases, attenuated the histological abnormalities in liver and decreased the plasma levels of TNF-α and IL-6 in LPS/D-Gal-insulted mice. In addition, Tofacitinib suppressed the activation of the caspase cascade, decreased the level of cleaved caspase-3, and reduced the count of TUNEL-positive cells. Treatment with Tofacitinib alleviated LPS/D-Gal-induced acute hepatitis. JAK maybe become a promising target for the control of inflammation-based liver disorders.

Liver fibrosis inhibits lethal injury through D-galactosamine/lipopolysaccharide-induced necroptosis

Objective: To explore the new mechanism of liver fibrosis through D-galactosamine/lipopolysaccharide (D-GalN/LPS)-induced necroptosis as an entry point to inhibit lethal injury. Methods: The carbon tetrachloride (CCl4)-induced mouse model of liver fibrosis was established. At 6 weeks of fibrosis, the mice were challenged with a lethal dose of D-GalN/LPS, and the normal mice treated with the same treatment were used as the control. The experiment was divided into four groups: control group (Control), acute injury group (D-GalN/LPS), liver fibrosis group (Fib), and liver fibrosis + acute challenge group (Fib + D-GalN/LPS). Quantitative PCR and immunofluorescence were used to analyze the expression of necroptosis key signal molecules RIPK1, RIPK3, MLKL and/or P-MLKL in each group. Normal mice were treated with inhibitors targeting key signaling molecules of necroptosis, and then given an acute challenge. The inhibitory effect of D-GalN/LPS-induced-necroptosis on acute liver injury was evaluated according to the changes in transaminase levels and liver histology. Liver fibrosis spontaneous ablation model was established, and then acute challenge was given. Necroptosis key signal molecules expression was analyzed in liver tissue of mice in each group and compared by immunohistochemistry. The differences between groups were compared with t-test or analysis of variance. Results: Quantitative PCR and immunofluorescence assays result showed that D-GalN/LPS-induced significant upregulation of RIPK1, RIPK3, MLKL and/or P-MLKL. Necroptosis key signal molecules inhibition had significantly reduced D-GalN/LPS-induced liver injury, as manifested by markedly reduced serum ALT and AST levels with improvement in liver histology. Necroptosis signaling molecules expression was significantly inhibited in fibrotic livers even under acute challenge conditions. Additionally, liver fibrosis with gradual attenuation of fibrotic ablation had inhibited D-GalN/LPS-induced necroptosis. Conclusion: Liver fibrosis may protect mice from acute lethal challenge injury by inhibiting D-GalN/LPS-induced necroptosis.

Maresin1 Protect Against Ferroptosis-Induced Liver Injury Through ROS Inhibition and Nrf2/HO-1/GPX4 Activation.

Drugs, viruses, and chemical poisons stimulating live in a short period of time can cause acute liver injury (ALI). ALI can further develop into serious liver diseases such as cirrhosis and liver cancer. Therefore, how to effectively prevent and treat ALI has become the focus of research. Numerous studies have reported Maresin1 (MaR1) has anti-inflammatory effect and protective functions on organs. In the present study, we used d-galactosamine/lipopolysaccharide (D-GalN/LPS) to establish an ALI model, explored the mechanism of liver cells death caused by D-GalN/LPS, and determined the effect of MaR1 on D-GalN/LPS-induced ALI. In vivo experiments, we found that MaR1 and ferrostatin-1 significantly alleviated D-GalN/LPS-induced ALI, reduced serum alanine transaminase and aspartate transaminase levels, and improved the survival rate of mice. Meanwhile, MaR1 inhibited hepatocyte death, inhibited tissue reactive oxygen species (ROS) expression, reduced malondialdehyde (MDA), reduced glutathione (GSH), GSH/oxidized glutathione (GSSG), and iron content induced by D-GalN/LPS in mice. In addition, MaR1 inhibited ferroptosis-induced liver injury through inhibiting the release of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and IL-6. Subsequently, western blot showed that MaR1 improved the expression of nuclear factor E2-related factor 2(Nrf2)/heme oxygenase-1 (HO-1)/glutathione peroxidase 4 (GPX4). In vitro experiments, we found that MaR1 inhibited LPS-induced and erastin-induced cell viability reduction. Meanwhile, we found that MaR1 increased the MDA and GSH levels in cells. Western blot showed that MaR1 increased the expression level of Nrf2/HO-1/GPX4. Next, the Nrf2 was knocked down in HepG2 cells, and the results showed that the protective effect of MaR1 significantly decreased. Finally, flow cytometry revealed that MaR1 inhibited ROS production and apoptosis. Overall, our study showed MaR1 inhibited ferroptosis-induced liver injury by inhibiting ROS production and Nrf2/HO-1/GPX4 activation.

Vitexin attenuates autoimmune hepatitis in mouse induced by syngeneic liver cytosolic proteins via activation of AMPK/AKT/GSK-3β/Nrf2 pathway

Autoimmune hepatitis (AIH) is a chronic progressive liver disease that currently does not have a successful therapeutic option. Vitexin, a bioflavonoid isolated from various medicinal plants, possesses a variety of activities; however, whether vitexin protects against AIH remains unclear. Therefore, the current study aims to investigate the hepatoprotective effects and mechanism of action of vitexin in both an experimental autoimmune hepatitis (EAH) mouse model and in D-galactosamine/lipopolysaccharide (D-GalN/LPS)-induced hepatocyte injury. Syngeneic liver antigen S100 was used to establish EAH. Vitexin treatment significantly decreased the infiltration of inflammatory and CD4+ T cells in the liver, reduced ALT and AST levels in the serum and attenuated hepatic injury due to oxidative stress. Moreover, vitexin mitigated the upregulation of Bax and cleaved caspase-3 and the downregulation of Bcl-2 in the livers of AIH mice. These regulations were accompanied by not only increased phosphorylation of AMPK, AKT and GSK-3β but also activation of Nrf2. Furthermore, vitexin inhibited apoptosis and the overexpression of inflammatory cytokines in D-GalN/LPS-treated AML12 cells. In addition, vitexin enhanced the phosphorylation of AMPK, AKT and GSK-3β. When AML12 cells were treated with an inhibitor of AMPK/AKT or specific siRNA targeting Nrf2, vitexin did not further induce the activation of Nrf2/HO-1. A molecular docking study confirmed that vitexin could interact with AMPK through hydrogen bonding interactions. In conclusion, vitexin ameliorated hepatic injury in EAH mice through activation of the AMPK/AKT/GSK-3β pathway and upregulation of the Nrf2 gene.

Protective role of Saikosaponin d in d-galactosamine and lipopolysaccharide-induced liver injury in hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀)

Abuse of antibiotics and chemical drugs will lead to environmental contaminants in the aquatic system posing a threat to fish growth and survival. The goal of this study to evaluate the hepatoprotective and immunopotentiation of saikosaponin d (SSd) on the D-GalN/LPS (D-galactosamine/lipopolysaccharide) induced liver injury of hybrid grouper (E. fuscoguttatus♀ × E. lanceolatus♂) in vivo and in vitro. Saikosaponin d was given in vivo in the diet at dosages ranging from 100 to 800 mg/kg for fifty-six days before D-galactosamine/lipopolysaccharide intoxication. At 24 h post-injection, liver samples were taken for enzyme activity and molecular level analyses. Results showed that SSd at 200 and 400 mg/kg substantially decreased IL-6, TNF-α, and IL-1β levels in liver tissue, and markedly immune inflammatory response and down-regulated apoptosis (P < 0.05). In order to further study the liver protection mechanism of SSd, we used an in vitro experiment. The hepatocytes were treated with various doses of SSd (100, 200 and 400 ng/mL) before (pre-treatment) incubation with LPS (1 μg/mL) and D-GalN (20 mM) in the culture medium. Then the morphology of liver cells was observed by microscope, hepatocyte viability was investigated by the CCK-8, mRNA expression of immune related genes (caspase-9, caspase-3, and caspase-8), and pro-inflammatory cytokines (IL-8, IL-1β, and IL-6) in the hepatocytes were studied by qRT-PCR. The results showed that at concentrations of 100 and 200 ng/mL, SSd enhanced viability of cell, inhibited the level of apoptosis rate (P < 0.05). The observation of morphology also showed that SSd effectively inhibited mortality of the hepatocytes. Furthermore, the pro-inflammatory cytokines mRNA and expression of immune related genes was improved in 200 ng/mL SSd treatments (P < 0.05). In brief, SSd can protect D-galactosamine/lipopolysaccharide-induced hepatocytes harm through the prevention of immune inflammatory response and apoptosis. These results provide new perspective for improving fish health.

Activation of PKM2 metabolically controls fulminant liver injury via restoration of pyruvate and reactivation of CDK1

Accumulating evidence indicates that metabolic events profoundly modulate the progression of various diseases. Pyruvate is a central metabolic intermediate in glucose metabolism. In the present study, the metabolic status of pyruvate and its pharmacological significance has been investigated in mice with lipopolysaccharide/D-galactosamine (LPS/D-Gal)-induced fulminant liver injury. Our results indicated that LPS/D-Gal exposure decreased the activity of pyruvate kinase and the content of pyruvate, which were reversed by the PKM2 activator TEPP-46. Pretreatment with TEPP-46 or supplementation with the cell-permeable pyruvate derivate ethyl pyruvate (EP) attenuated LPS/D-Gal-induced liver damage. Interestingly, post-insult intervention of pyruvate metabolism also resulted in beneficial outcomes. The phospho-antibody microarray analysis and immunoblot analysis found that the inhibitory phosphorylation of cyclin dependent kinase 1 (CDK1) was reversed by TEPP-46, DASA-58 or EP. In addition, the therapeutic benefits of PKM2 activator or EP were blunted by the CDK1 inhibitor Ro 3306. Our data suggests that LPS/D-Gal exposure-induced decline of pyruvate might be a novel metabolic mechanism underlies the development of LPS/D-Gal-induced fulminant liver injury, PKM2 activator or pyruvate derivate might have potential value for the pharmacological intervention of fulminant liver injury.

Niujiaodihuang Detoxify Decoction inhibits ferroptosis by enhancing glutathione synthesis in acute liver failure models

Ethnopharmacological relevanceNiujiaodihuang Detoxify Decoction (NDD) is an integrated traditional Chinese medicine prescription that has been used as a therapeutic agent for the treatment of acute liver failure (ALF). However, the mechanisms underlying its action remain unclear.Aim of the study: To determine the protective effect of NDD on D-galactosamine/lipopolysaccharide (D-GalN/LPS)-induced ALF and explore the underlying mechanisms. Materials and methodsWe characterized the NDD fingerprint by HPLC and established D-GalN/LPS-induced ALF models in Sprague–Dawley rats and LO2 cells. Next, we measured the protective and antiferroptotic effects of NDD in vivo and in vitro. To further investigate the molecular mechanisms underlying the effects of NDD, we performed metabolomic analysis of the liver tissue using LC-MS/MS. ResultsResults of serum biochemical analysis, liver histopathology, and cell viability showed that NDD effectively relieved the liver injury. It reduced the accumulation of labile iron and alleviated lipid peroxidation by enhancing GPX4 activity. The mitochondrial morphology indicated that NDD exerted its hepatoprotective effect through an antiferroptotic activity. Metabolomic analysis showed that NDD treatment increased the levels of cysteine, decreased those of glutamate, and ameliorated the D-GalN/LPS-induced reduction in the levels of glutathione (GSH). The results for intracellular levels of reduced (GSH) and oxidized (GSSG) glutathione were consistent with those of metabolomic analysis. ConclusionOur findings indicate that NDD exerts hepatoprotective activity by evoking the reprogramming of GSH metabolism, and thereby, inhibiting ferroptosis.

Silencing long noncoding RNA NEAT1 alleviates acute liver failure via the EZH2-mediated microRNA-139/PUMA axis.

This study aimed to investigate the role of long noncoding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1) in the development of ALF. We collected blood samples from patients with acute liver failure (ALF) and established an ALF mouse model induced by D-galactosamine/Lipopolysaccharide (D-GalN/LPS) for in vivo studies. Peripheral blood mononuclear cells (PMBCs) induced with LPS were isolated for in vitro experiments. Survival tests, histological analysis, and biochemical indicator assays were conducted. Luciferase assay was performed to determine the binding affinity between microRNA-139 (miR-139) and p53-upregulated modulator of apoptosis (PUMA). Expression of lncRNA NEAT1, enhancer of zeste homolog 2 (EZH2), and PUMA was upregulated, while the expression of miR-139 was downregulated in clinical samples and D-GalN/LPS induced ALF mouse model. LncRNA NEAT1 promoted the enrichment of H3K27me3 on the promoter region of miR-139 via EZH2, which led to suppression of miR-139. The inhibition of miR-139 resulted in the upregulation of its downstream target PUMA. The NEAT1/miR-139/PUMA pathway upregulated the production of pro-inflammatory cytokines, tumor necrosis factor alpha, interleukin (IL)-6, and IL-1β, thereby mediating the progression of ALF. In conclusion, silencing lncRNA NEAT1 upregulated the expression of miR-139 through EZH2, leading to the downregulation of PUMA, which alleviated the development of ALF.

Accumulation of Nuclear PKM2 Promotes LPS/D-Gal-Induced Fulminant Liver Injury via Reduction of Pyruvate and Inactivation of CDK1

Background: Accumulating evidence indicates that metabolic events profoundly modulate the progression of various diseases. The pyruvate kinases catalyze the production of pyruvate and pyruvate kinase M2 (PKM2) is a unique isoform involved in the development of tumors. In the present study, the pathological significance of PKM2 has been investigated in mice with lipopolysaccharide/D-galactosamine (LPS/D-Gal)-induced fulminant liver injury. Methods: Fulminant liver injury was induced in mice by intraperitoneal injection of LPS/D-Gal, the level of nuclear PKM2, the activity of pyruvate kinase and the content of pyruvate were determined. To investigated the significance of PKM2/ pyruvate, the PKM2 modulator TEPP-46, DASA-58 or the cell permeable ethyl pyruvate (EP) was administered and the degree of hepatocyte apoptosis and liver damage were evaluated. In addition, phospho-antibody microarray was used to identify the underlying signaling pathways. Findings: LPS/D-Gal exposure increased the nuclear level of PKM2 but decreased the activity of pyruvate kinase and the content of pyruvate. Treatment with the PKM2 modulator TEPP-46 or supplementation with ethyl pyruvate (EP) suppressed LPS/D-Gal-induced liver damage. Interestingly, post-insult administration of TEPP-46, another PKM2 modulator DASA-58 or EP also resulted in beneficial outcomes. The phospho-antibody microarray analysis found that LPS/D-Gal induced inhibitory phosphorylation of cyclin dependent kinase 1 (CDK1), which was reversed by TEPP-46, DASA-58 or EP. In addition, the therapeutic benefits of TEPP-46 or EP were blunted by the CDK1 inhibitor Ro 3306. Interpretation: Our data suggests that LPS/D-Gal exposure-induced accumulation of nuclear PKM2, decline of pyruvate and inactivation of CDK1 might be a novel metabolic mechanism underlies the development of LPS/D-Gal-induced fulminant liver injury, PKM2/pyruvate might be a promising target for the pharmacological intervention of fulminant hepatocyte damage. Funding: This work was supported by the grants from the National Natural Science Foundation of China (No. 81871606) and the grant from Science and Technology Research Program of Chongqing Municipal Education Commission (No. KJQN201900435). Declaration of Interest: None to declare. Ethical Approval: The Ethics Committee of Chongqing Medical University approved all mouse experiments.

Pterostilbene Exerts Hepatoprotective Effects through Ameliorating LPS/D-Gal-Induced Acute Liver Injury in Mice.

Acute liver injury (ALI) refers to abnormalities in liver function caused by various causes and accompanied by poor prognosis and high mortality. Common predisposing factors for the disease are viral hepatitis, bacteria, alcohol, and certain hepatotoxic drugs. Inflammatory response and oxidative stress are critical for the pathogenesis of ALI. Pterostilbene (Pte), a natural polyphenol product extracted from blueberries and grapes, has been reported that exerted multiple biological activities, including antioxidative, anti-inflammatory, anti-carcinogenic, and anti-apoptotic properties. However, there is very little data showing the hepatoprotective effect of Pte on lipopolysaccharide/D-galactosamine (LPS/D-Gal)-induced ALI in mice. In this study, the possible protective effect and potential mechanisms of Pte on ALI are being investigated. It has been found that Pte markedly ameliorates LPS/D-Gal-induced inflammatory infiltration, hemorrhage, and dissociation of the hepatic cord, reducing the myeloperoxidase (MPO) activity in liver tissues and serum levels of alanine transaminase (ALT) and aspartate aminotransferase (AST) in ALI. Pte also inhibits LPS/D-Gal-induced secretion of pro-inflammatory cytokine tumor necrosis factor-a (TNF-α), interleukin 6 (IL-6), and interleukin 1β (IL-1β) in liver tissues. Furthermore, the western blot analysis reveals that LPS/D-Gal-activated nuclear factor-kappa B (NF-κB) is significantly inhibited by Pte, and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and heme oxygenase-1 (HO-1) are upregulated by Pte. In conclusion, our results suggest that Pte exerts anti-inflammatory and antioxidative effects, which might contribute to ameliorating LPS/D-Gal-induced ALI in mice. Pte has the potential to be a preventive hepatoprotective agent.

Polyphenols from Morchella angusticepes Peck attenuate D-galactosamine/lipopolysaccharide-induced acute hepatic failture in mice

Abstract We investigated the effect of polyphenols extracted from M. angusticepes Peck (PMP) on D-galactosamine/lipopolysaccharide (D-GalN/LPS) induced acute hepatic failure (AHF) in mice. Results indicated that administration of PMP relieved the leakage of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The level of serum ALT was reduced in groups of P-H (800 mg PMP/kg BW) and P-L (400 mg PMP/kg BW) by 44.6% and 31.8%, respectively. RT-PCR and Western blot analyses showed that NF-E2-related factor 2 (Nrf2), PPARα, PPARγ gene and protein were up-regulated after injection D-GalN/LPS. In contrast, PMP pretreatment noticeably prevented D-GalN/LPS-induced hepatocyte apoptosis and steatosis. It suggested that PMP attenuated D-GalN/LPS-induced AHF in mice, which was likely attributed to the co-activation of Nrf2, PPARα, PPARγ and alleviating the oxidative stress reaction, reducing the body inflammatory response and regulating the lipid metabolism.

LGR4 protects hepatocytes from injury in mouse.

Leucine-rich repeat G protein-coupled receptors (LGRs) and their endogenous ligands R-spondin1-4 (Rspo) are critical in embryonic development and in maintenance of stem cells. The functions of the Rspo-LGR system in differentiated cells remain uncharacterized. In this study, the expression profiles of LGRs and Rspos were characterized in mature hepatocytes. A liver-specific knockout of LGR4 in mouse was generated and used to study hepatic ischemia/reperfusion-induced injury (HIRI) as well as lipopolysaccharide/ D- galactosamine (LPS/D-Gal)-induced liver injury. We have demonstrated that, in adult liver, LGR4 is expressed in hepatocytes and responds to Rspo1 with internalization. Rspo1 is responsive to various nutritional states and to mTOR signaling. Activation of LGR4 by Rspo1 significantly reduced tumor necrosis factor-α (TNFα)-induced cell death, and levels of NF-κB-p65 and caspase-3 in cultured hepatocytes. Knockdown of hepatic LGR4 rendered hepatocytes more vulnerable to TNFα-induced damage in cultured primary cells and in the setting of HIRI and LPS/D-Gal-induced liver injury. Rspo1 potentiated both basal and Wnt3a-induced stabilization of β-catenin. Disruption of β-catenin signaling reversed the protective effects of Rspo1 on TNFα-induced hepatocyte toxicity. LGR4 knockdown increased nuclear translocation of NF-κB-p65 in response to acute injury. Overexpression of IKKβ attenuated the protective effects of Rspo1 on TNFα-induced cell death. In conclusion, the Rspo1-LGR4 system represents a novel pathway for cytoprotection and modulation of stress-induced tissue damage. NEW & NOTEWORTHY Functional LGR4 is present in mature hepatocytes. R-spodin1 protects hepatocytes from tumor necrosis factor-α-induced cell death. Liver-specific knockdown of LGR4 renders liver more susceptible to acute injury. LGR4 protects hepatocytes from injury by inhibition of NF-κB signaling.

Esculin prevents Lipopolysaccharide/D-Galactosamine-induced acute liver injury in mice

Liver injury is an important cause of serious liver disease and is characterized by inflammatory and oxidative responses. Esculin, a coumarinic derivative found in Aesculus hippocastanum L., has been shown to exhibit anti-inflammatory and anti-oxidative effects. Here, we investigated the effects and molecular mechanism of esculin on Lipopolysaccharide/D-Galactosamine (LPS/D-Gal)-induced acute liver injury. A mouse model for acute liver injury was induced by intraperitoneal injection with D-Gal and LPS, and was assessed by histology, and serum transaminase analyses. The results showed that esculin significantly reduced the pathological symptoms of acute liver injury, as well as serum AST and ALT levels. LPS/D-Gal-induced liver myeloperoxidase (MPO) activity and malondialdehyde (MDA) content were also suppressed by esculin. Furthermore, LPS/D-Gal-induced liver tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) production were attenuated by esculin. Our data demonstrate that esculin can inhibit nuclear factor kappa B (NF-κB) activation as well as increase nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression. In conclusion, this paper demonstrates that esculin protects liver injury induced by LPS/D-Gal via inhibiting inflammatory and oxidative responses.

The hepatoprotective effects of Radix Bupleuri extracts against D-galactosamine/lipopolysaccharide induced liver injury in hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀)

The present study is aiming at evaluating the hepatoprotective of Radix Bupleuri extracts (RBE) on the d-galactosamine/lipopolysaccharide (D-GalN/LPS) induced liver injury of hybrid grouper in vitro and in vivo. In vitro, RBE (0, 200, 400 and 800 μg/ml) was added to the hybrid grouper primary hepatocytes before (pretreatment) the incubation of the hepatocytes with D-GalN (20 mM) plus LPS (1 μg/ml) in the culture medium. RBE at concentrations of 200, 400 and 800 μg/ml significantly improved cell viability and inhibited the elevation of TNF-α, IL-1β and IL-6 and significantly down-regulated the caspase-3, caspase-9 and P53 mRNA levels. In vivo administration of RBE at the doses of 0, 200, 400, 800 and 1600 mg/kg in the diet for 8 weeks prior to D-GalN (500 mg/kg) and LPS (20 μg/kg) intoxication. The study indicated that the RBE not only ameliorated liver injury, as evidenced by well-preserved liver architecture, but also significantly increased hepatic antioxidant enzymes activities in the D-GalN/LPS-induced liver injury animal model. Further demonstrating the protective effects of the RBE, we found that pretreatment with the RBE up-regulated the expression of antioxidant genes (GPx and MnSOD), while down-regulated apoptosis-related genes (caspase-3, caspase-9 and P53), immune related genes (MHC2 and TLR3) and pro-inflammatory cytokines (TOR and IKKα) mRNA expression in the liver of hybrid grouper. In brief, the present study showed that RBE can protect hepatocyte injury induced by D-GalN/LPS through elevating antioxidant enzyme activity and suppressing apoptosis and immune inflammatory responses. The results support the use of RBE as a hepatoprotective in fish.

Betulin inhibits lipopolysaccharide/D-galactosamine-induced acute liver injury in mice through activating PPAR-γ

Betulin is a phenolic flavonoid which has been reported to possess a mass of pharmacological properties, especially anti-inflammatory activity. The purpose of this study was to explore the protective effects and possible mechanism of betulin against lipopolysaccharide/D-galactosamine (LPS/D-Gal)-induced acute liver injury. D-Gal and LPS were intraperitoneally injected to develop acute liver injury animal model. Betulin (2, 4 or 8 mg/kg) were given 1 h before LPS/D-Gal instillation. Liver tissues and plasma samples were collected 9 h after LPS/D-Gal were given. The results indicated that betulin dramatically decreased liver pathologic changes, myeloperoxidase (MPO) activity, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. Simultaneously, the levels of interleukin (IL-1β) and tumor necrosis factor (TNF-α) in serum and liver tissues were both attenuated by betulin. Besides, betulin suppressed NF-κB pathway activation in a dose-dependently manner. Betulin increased the expression of PPAR-γ in a dose-dependent manner. In conclusion, all these results revealed that betulin could possess potential therapeutic effect for LPS/D-Gal-induced acute liver injury.

Costunolide protects lipopolysaccharide/d-galactosamine–induced acute liver injury in mice by inhibiting NF-κB signaling pathway

BackgroundCostunolide, a well-known sesquiterpene lactone, has been reported to have anti-inflammatory and anti-oxidative effects. MethodsIn this study, we aim to investigate the protective effects and mechanism of costunolide on lipopolysaccharide/d-galactosamine (LPS/D-Gal)–induced acute liver injury. Acute liver injury animal model was induced by intraperitoneal injection with D-Gal and LPS. Costunolide (10, 20, and 30 mg/kg) was injected intraperitoneally 1 h before or after LPS/D-Gal treatment. ResultsThe results showed that costunolide significantly attenuated liver pathologic changes, as well as alanine aminotransferase and aspartate aminotransferase levels in serum. Meanwhile, costunolide inhibited the expressions of interleukin (IL-1β) and tumor necrosis factor (TNF-α) in liver tissues in a dose-dependent manner. Furthermore, costunolide dose dependently inhibited LPS/D-Gal–induced NF-κB activation. ConclusionsIn conclusion, this study suggested that costunolide could attenuate LPS/D-Gal–induced liver injury and might be a potential therapeutic reagent for liver injury.

Protective effect of glycogen synthase kinase 3β inhibition via peroxisome proliferator-activated receptor alpha activation in mice with acute liver failure

Objective: To investigate the role of the glycogen synthase kinase 3β (GSK3β) and the peroxisome proliferator-activated receptor alpha (PPARα) signaling pathway in acute liver failure and related mechanisms in a mouse model of acute liver failure induced by D-galactosamine/lipopolysaccharide (D-GalN/LPS). Methods: C57BL/6 mice were given intraperitoneal injection of D-GalN/LPS to establish a mouse model of acute liver failure. SB216763 was used to inhibit the activity of GSK3β and PPARα siRNA was used to inhibit the expression of PPARα. Western blotting was used to measure the expression of PPARα protein. The changes in liver pathology were observed to evaluate liver injury, and the serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured to assess liver function. Quantitative real-time PCR was used to measure the mRNA expression of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-12p40 (IL-12p40), and PPARα. A one-way analysis of variance was used for comparison of means between multiple groups; the least significant difference test was used for data with homogeneity of variance, and the Games-Howell method was used for data with heterogeneity of variance. Results: In the mice with liver failure induced by D-GalN/LPS, GSK3β inhibition promoted the mRNA and protein expression of PPARα (F = 13.18 and 301.36, P = 0.00 and 0.00). In the mice with acute liver failure induced by D-GalN/LPS, GSK3β inhibition alleviated liver bleeding, inflammation, and necrosis and reduced the serum levels of ALT (F = 25.16, P = 0.000) and AST (F = 12.96, P = 0.001), as well as the mRNA expression of TNF-α (F = 32.17, P = 0.00), IL-1β (F = 11.57, P = 0.005), and IL-12p40 (F = 14.17, P = 0.015) in liver tissue. The inhibition of PPARα expression reversed the liver-protecting effect of GSK3β inhibition, which manifested as aggravation in liver bleeding, inflammation, and necrosis, increases in the serum levels of ALT (F = 25.16, P = 0.001) and AST (F = 12.96, P = 0.000), and an increase in the mRNA expression of TNF-α (F = 32.17, P = 0.00), IL-1β (F = 11.57, P = 0.024), and IL-12p40 (F = 14.17, P = 0.001) in liver tissue. Conclusion: In mice with acute liver failure induced by D-GalN/LPS, the GSK3β-PPARα-inflammatory factor signaling pathway may play an important role. GSK3β inhibition has a protective effect in mice with acute liver failure possibly by activating the inhibitory inflammatory factor of PPARα.

Protective effect of astragaloside IV against acute liver failure in experimental mice

Objective: To investigate the clinical effect of astragaloside IV in the early treatment of mice with acute liver failure and possible mechanisms. Methods: A mouse model of acute liver failure induced by D-galactosamine/lipopolysaccharide (D-GalN/LPS) was established, and the mice were given astragaloside IV at different doses. The survival rate of mice, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, liver histopathological changes, apoptosis of hepatocytes, and the expression of superoxide dismutase (SOD) and malondialdehyde (MDA) were measured in each group. The least significant difference test was used for data with homogeneity of variances, the Dunnett's T3 test was used for data with heterogeneity of variance, and the Kaplan-Meier method was used for survival analysis. Results: Compared with the model group, the high-dose astragaloside IV group had a significant increase in the 48-hour survival rate [60% (9/15) vs 13.3% (2/15), P < 0.05], significant reductions in the serum ALT and AST levels (P < 0.01), and significant reductions in liver histopathological indices and the degree of apoptosis of hepatocytes (P < 0.01), as well as a significant reduction in the content of MDA in liver homogenate (P < 0.01) and a significant increase in the activity of SOD (P < 0.05). Conclusion: High-dose astragaloside IV has a significant protective effect against D-GalN/LPS-induced acute liver injury in mice, and its mechanisms may be associated with its effects against cell apoptosis and oxidative damage.