A Mouse Model of Non-Alcoholic Steatohepatitis and Hepatocellular Carcinoma Induced by Western Diet and Carbon Tetrachloride.

Non-alcoholic steatohepatitis (NASH) is a severe form of non-alcoholic fatty liver disease (NAFLD). Obesity is a known risk factor of NASH, which, in turn, increases the risk of developing cirrhosis (liver scarring) and hepatocellular carcinoma (HCC). In addition to being a potentially life-threatening condition, public health concerns surrounding NASH are amplified by the lack of FDA-approved treatments. Although various preclinical models reflecting both the histopathology and the pathophysiological progression of human NASH exist, most of these models are diet-based and require 6-13 months for NASH symptom manifestation. Here, we describe a simple and rapid-progression model of NASH and NASH-driven HCC in mice. Mice received a western diet equivalent (WD; i.e., a high-fat, high-fructose, and high-cholesterol diet), high-sugar water (23.1 g/L fructose and 18.9 g/L glucose), and weekly intraperitoneal injections of carbon tetrachloride (CCl4) at a dose of 0.2 µL/g of body weight. The resulting phenotype, consisting in liver fibrosis and HCC, appeared within 24 weeks of diet/treatment initiation and presented similar histological and transcriptomic features as human NASH and NASH-driven HCC, thereby supporting the adequacy of this preclinical model for the development and evaluation of drugs that can prevent or reverse these diseases.

Hepatic stellate cell-intrinsic role of SOCS1 in controlling hepatic fibrogenic response and the pro-inflammatory macrophage compartment during liver fibrosis.

Introduction: Hepatic stellate cells (HSC) become activated, differentiate to myofibroblasts and produce extracellular fibrillar matrix during liver fibrosis. The hepatic fibrogenic response is orchestrated by reciprocal interactions between HSCs and macrophages and their secreted products. SOCS1 can regulate several cytokines and growth factors implicated in liver fibrosis. Here we investigated the role of SOCS1 in regulating HSC activation. Methods: Mice lacking SOCS1 in HSCs (Socs1ΔHSC) were generated by crossing Socs1fl/fl and LratCre mice. Liver fibrosis was induced by carbon tetrachloride and evaluated by Sirius red staining, hydroxyproline content and immunostaining of myofibroblasts. Gene expression of pro-fibrogenic factors, cytokines, growth factors and chemokines were quantified by RT-qPCR. The phenotype and the numbers of intrahepatic leukocyte subsets were studied by flow cytometry. The impact of fibrosis on the development of diethyl nitrosamine-induced hepatocellular carcinoma was evaluated. Results: Socs1ΔHSC mice developed more severe liver fibrosis than control Socs1fl/fl mice that was characterized by increased collagen deposition and myofibroblast differentiation. Socs1ΔHSC mice showed a significant increase in the expression of smooth muscle actin, collagens, matrix metalloproteases, cytokines, growth factors and chemokines in the liver following fibrosis induction. The fibrotic livers of Socs1ΔHSC mice displayed heightened inflammatory cell infiltration with increased proportion and numbers of Ly6ChiCCR2+ pro-inflammatory macrophages. This macrophage population contained elevated numbers of CCR2+CX3CR1+ cells, suggesting impaired transition towards restorative macrophages. Fibrosis induction following exposure to diethyl nitrosamine resulted in more numerous and larger liver tumor nodules in Socs1ΔHSC mice than in Socs1fl/fl mice. Discussion: Our findings indicate that (i) SOCS1 expression in HSCs is a critical to control liver fibrosis and development of hepatocaellular carcinoma, and (ii) attenuation of HSC activation by SOCS1 regulates pro-inflammatory macrophage recruitment and differentiation during liver fibrosis.

Activated Natural Killer Cell Inoculation Alleviates Fibrotic Liver Pathology in a Carbon Tetrachloride-Induced Liver Cirrhosis Mouse Model.

Activated hepatic stellate cells (HSCs) play a detrimental role in liver fibrosis progression. Natural killer (NK) cells are known to selectively recognize abnormal or transformed cells via their receptor activation and induce target cell apoptosis and, therefore, can be used as a potential therapeutic strategy for liver cirrhosis. In this study, we examined the therapeutic effects of NK cells in the carbon tetrachloride (CCl4)-induced liver cirrhosis mouse model. NK cells were isolated from the mouse spleen and expanded in the cytokine-stimulated culture medium. Natural killer group 2, member D (NKG2D)-positive NK cells were significantly increased after a week of expansion in culture. The intravenous injection of NK cells significantly alleviated liver cirrhosis by reducing collagen deposition, HSC marker activation, and macrophage infiltration. For in vivo imaging, NK cells were isolated from codon-optimized luciferase-expressing transgenic mice. Luciferase-expressing NK cells were expanded, activated and administrated to the mouse model to track them. Bioluminescence images showed increased accumulation of the intravenously inoculated NK cells in the cirrhotic liver of the recipient mouse. In addition, we conducted QuantSeq 3' mRNA sequencing-based transcriptomic analysis. From the transcriptomic analysis, 33 downregulated genes in the extracellular matrix (ECM) and 41 downregulated genes involved in the inflammatory response were observed in the NK cell-treated cirrhotic liver tissues from the 1532 differentially expressed genes (DEGs). This result indicated that the repetitive administration of NK cells alleviated the pathology of liver fibrosis in the CCl4-induced liver cirrhosis mouse model via anti-fibrotic and anti-inflammatory mechanisms. Taken together, our research demonstrated that NK cells could have therapeutic effects in a CCl4-induced liver cirrhosis mouse model. In particular, it was elucidated that extracellular matrix genes and inflammatory response genes, which were mainly affected after NK cell treatment, could be potential targets.

Carbon tetrachloride exposure induces ovarian damage through oxidative stress and inflammatory mediated ovarian fibrosis.

Carbon tetrachloride (CCL4) is widely used as a chemical intermediate and as a feedstock in the production of chlorofluorocarbons. CCL4 is highly toxic in the liver, kidney, testicle, brain and other tissues. However, the effect of CCL4 on ovarian function has not been reported. In this study, we found that the mice treated with CCL4 showed decreased ovarian function with disturbed estrus cycle, decreased serum level of 17ß-estradiol and the reduced number of healthy follicles. Ovarian damage was accompanied by oxidative stress and the production of proinflammatory cytokines, especially interleukins. The indicators of oxidative stress, 4-Hydroxynonenal (4-HNE), 8-hydroxy-2´-deoxyguanosine (8-OHdG), 3-Nitrotyrosine (3-NT) and malondialdehyde (MDA), and the levels of proinflammatory cytokines IL-1α, IL-1ß, IL-6 and IL-11 were increased, while the antioxidants, including superoxide dismutase (SOD), nuclear factor erythroid2-related factor 2 (NRF2) and heme oxygenase-1 (HO-1), were decreased in the CCL4 group. In the CCL4 treated group, the results of Sirius Red staining, immunohistochemistry and qPCR indicated that proinflammatory cytokines caused further ovarian fibrosis. And CCL4 could also promote ovarian thecal cells to secrete inflammatory cytokines, resulting in fibrosis in vitro. In addition, CCL4 inhibited oocyte development and triggered oocyte apoptosis. In conclusion, CCL4 exposure causes ovarian damage by strong oxidative stress and the high expression of the proinflammatory cytokine mediated ovarian fibrosis.

Atmospheric CCl4 degradation in Antarctic tundra soils and the evaluation on its partial atmospheric lifetime with respect to soil.

Carbon tetrachloride (CCl4) is an anthropogenic gas with a long atmospheric lifetime and can catalyze the destruction of stratospheric ozone. Natural soils are believed to be important and widespread sinks of atmospheric CCl4, although poorly characterized due to a limited number of measurements. In this study, for the first time in situ static-chamber measurements and laboratory-based incubations for CCl4 fluxes were conducted at coastal Antarctic tundra. Results showed that soil in remote Antarctica is also acting as a CCl4 sink, with an average uptake rate of -2.2 ± 0.6 nmol m-2 d-1, which is comparable to the reported soil sinks in other regions of the world. No significant difference (p > 0.05) was found across different types of tundra, such normal upland tundra, coastal marsh tundra, and tundra in the sea animal colonies. Soil CCl4 fluxes did not show significant correlations (p > 0.05) with soil moisture, pH, TOC, TN, TP and Cl contents. Laboratory-based anoxic incubations showed that the uptake rates of CCl4 in tundra soil were suppressed; post-thermal sterilization incubations showed that soil CCl4 sink was enhanced; these results suggested that CCl4 degradation in tundra soil was likely an abiotic process preferring oxic environments. A rough extrapolation suggested that Antarctic tundra may degrade about 2.4 metric tons of atmospheric CCl4 each year. Combining soil CCl4 fluxes from this study and other literature reports, CCl4 partial lifetime with respect to the soil sink was evaluated to be 354 (235-474) years, which supported the recent viewpoint that the soil sink of CCl4 is smaller than previously thought.

Liver regeneration and ethanol detoxification: A new link in YAP regulation of ALDH1A1 during alcohol-related hepatocyte damage.

Yes-associated protein (YAP), a central effector in the Hippo pathway, is involved in the regulation of organ size, stem cell self-renewal, and tissue regeneration. In this study, we observed YAP activation in patients with alcoholic steatosis, hepatitis, and cirrhosis. Accumulation of this protein in the nucleus was also observed in murine livers that were damaged after chronic-plus-single binge or moderate ethanol ingestion combined with carbon tetrachloride intoxication (ethanol/CCl4 ). To understand the role of this transcriptional coactivator in alcohol-related liver injury, we knocked out the Yap1 gene in hepatocytes of floxed homozygotes through adeno-associated virus (AAV8)-mediated deletion utilizing Cre recombinase. Yap1 hepatocyte-specific knockouts (KO) exhibited hemorrhage, massive hepatic necrosis, enhanced oxidative stress, elevated hypoxia, and extensive infiltration of CD11b+ inflammatory cells into hepatic microenvironments rich for connective tissue growth factor (Ctgf) during ethanol/CCl4 -induced liver damage. Analysis of whole-genome transcriptomics indicated upregulation of genes involved in hypoxia and extracellular matrix (ECM) remodeling, whereas genes related to hepatocyte proliferation, progenitor cell activation, and ethanol detoxification were downregulated in the damaged livers of Yap1 KO. Acetaldehyde dehydrogenase (Aldh)1a1, a gene that encodes a detoxification enzyme for aldehyde substrates, was identified as a potential YAP target because this gene could be transcriptionally activated by a hyperactive YAP mutant. The ectopic expression of the human ALDH1A1 gene caused increase in hepatocyte proliferation and decrease in hepatic necrosis, oxidative stress, ECM remodeling, and inflammation during ethanol/CCl4 -induced liver damage. Taken together, these observations indicated that YAP was crucial for liver repair during alcohol-associated injury. Its regulation of ALDH1A1 represents a new link in liver regeneration and detoxification.

Effect of Acute Liver Injury on Pharmacokinetics and Tissue Distribution of Baicalin Magnesium in Rats / 中国实验方剂学杂志

ObjectiveTo establish a high performance liquid chromatography （HPLC） for simultaneous determination of baicalin magnesium and baicalein in rat plasma and tissues， and to investigate the effect of acute liver injury on pharmacokinetics and tissue distribution of baicalin magnesium in rats. MethodAcute liver injury rat model was induced by carbon tetrachloride （CCl4）. Normal rats and acute liver injury model rats were given an equal dose （287.31 mg·kg-1） of baicalin magnesium aqueous solution by intragastric administration， the orbital blood was collected at different time points， and HPLC was used to simultaneously determine the concentrations of baicalin magnesium and baicalein in rat plasma at each time point， the concentration-time curves were drawn， the pharmacokinetic parameters were calculated with DAS 3.0， and SPSS 23.0 was used for statistical analysis. After oral administration of baicalin magnesium aqueous solution， HPLC was used to simultaneously determine the contents of baicalin magnesium and baicalein in rat liver， lung， kidney， stomach， brain and small intestine at different time points， the mobile phase was 0.1% phosphoric acid aqueous solution-methanol， and the detection wavelength was 278 nm. ResultIn the acute liver injury model group， the peak concentration （Cmax） of baicalin magnesium was 0.58 times that of the normal group， the area under concentration-time curve （AUC0-t） was 0.5 times that of the normal group （P<0.05）， the apparent volume of distribution （Vd） was 2.3 times that of the normal group （P<0.05）， and baicalein is almost undetectable in plasma. The content of baicalin magnesium in liver， stomach and brain of the acute liver injury model group was higher than that of the normal group at each time point， while the content of baicalin magnesium in the samples of lung at 8 h， kidney at 8 h and 12 h， and small intestine at 0.333 h was lower than that of the normal group. The content of baicalein in lung， stomach and small intestine of the model group was higher than that of the normal group at each time point， while the content of baicalein in the tissue samples of liver at 6， 8 h and kidney at 0.333， 4， 6 h was lower than that in the normal group， and baicalein could hardly be detected in the brain. ConclusionAfter intragastric administration of the same dose of baicalin magnesium aqueous solution， acute liver injury induced by CCl4 can affect the pharmacokinetics and tissue distribution characteristics of baicalin magnesium in rats， and there is biotransformation of baicalin magnesium and baicalein in liver， lung， kidney， stomach and small intestine.

Mechanism of Zhizi Prescription in Protection of CCl4-induced Acute and Subacute Liver Injury in Mice / 中国实验方剂学杂志

ObjectiveTo investigate the protective effect of Zhizi prescription （ZZP） on carbon tetrachloride （CCl4）-induced acute and subacute liver injury and its mechanism. MethodAcute and subacute liver injury animal models were induced. C57 mice were randomly divided into a normal group， model group， obeccholic acid group， ZZP high-dose （0.5 g·kg-1） group， and ZZP low-dose （0.25 g·kg-1） group. According to the experiment design， the serum and liver tissue of mice were collected after the last administration. Hematoxylin-eosin （HE） and Sirius staining was used to observe the liver pathological changes. Serum alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， total bilirubin （TBIL）， liver homogenate hydroxyproline （Hyp）， malondialdehyde （MDA）， and superoxide dismutase （SOD） levels were determined by kit. The levels of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in the liver tissue were determined by enzyme-linked immunosorbent assay （ELISA）. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the mRNA expressions of collagen 1A1 （Col1a1）， collagen 3A1 （Col3a1）， fibronectin （FN）， transforming growth factor β receptor Ⅱ （Tgfbr2） and α-smooth muscle actin （α-SMA） in the liver tissue. ResultIn terms of the acute liver injury， as compared with the normal group， the levels of ALT， AST， TBIL and MDA in the model group were significantly increased （P<0.01）， while the activity of liver SOD was significantly decreased （P<0.01）. Compared with model group， the ZZP high-dose and low-dose groups both significantly reduced the degree of liver cell injury， and protected the acute liver injury induced by CCl4. The ZZP high-dose group had a better effect than the ZZP low-dose group. In terms of the subacute liver injury， the levels of ALT， AST， MDA，TNF-α and IL-6 in the model group were significantly increased （P<0.01）， while the activity of liver SOD was significantly decreased （P<0.01）. As compared with the model group， liver Hyp content in the ZZP high-dose and low-dose groups was significantly decreased （P<0.01）， and the collagen deposition in liver of both groups was significantly reduced. The ZZP high-dose group also significantly down-regulated the mRNA expressions of α-SMA， Col1a1， Col3a1， FN， and Tgfbr2 in the liver of mice （P<0.05， P<0.01）. ConclusionZZP effectively protects the acute and subacute liver injury induced by CCl4， and the protective effect is proportional to its concentration. The mechanism may be related to the increase of the activity of antioxidant enzymes in the liver tissue， the decrease of the level of lipid peroxidation， and the inhibition of inflammatory response， thus reducing collagen deposition and improving early liver fibrosis.

Mechanism of Zhizi Prescription in Protection of CCl4-induced Acute and Subacute Liver Injury in Mice / 中国实验方剂学杂志

ObjectiveTo investigate the protective effect of Zhizi prescription （ZZP） on carbon tetrachloride （CCl4）-induced acute and subacute liver injury and its mechanism. MethodAcute and subacute liver injury animal models were induced. C57 mice were randomly divided into a normal group， model group， obeccholic acid group， ZZP high-dose （0.5 g·kg-1） group， and ZZP low-dose （0.25 g·kg-1） group. According to the experiment design， the serum and liver tissue of mice were collected after the last administration. Hematoxylin-eosin （HE） and Sirius staining was used to observe the liver pathological changes. Serum alanine aminotransferase （ALT）， aspartate aminotransferase （AST）， total bilirubin （TBIL）， liver homogenate hydroxyproline （Hyp）， malondialdehyde （MDA）， and superoxide dismutase （SOD） levels were determined by kit. The levels of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in the liver tissue were determined by enzyme-linked immunosorbent assay （ELISA）. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the mRNA expressions of collagen 1A1 （Col1a1）， collagen 3A1 （Col3a1）， fibronectin （FN）， transforming growth factor β receptor Ⅱ （Tgfbr2） and α-smooth muscle actin （α-SMA） in the liver tissue. ResultIn terms of the acute liver injury， as compared with the normal group， the levels of ALT， AST， TBIL and MDA in the model group were significantly increased （P<0.01）， while the activity of liver SOD was significantly decreased （P<0.01）. Compared with model group， the ZZP high-dose and low-dose groups both significantly reduced the degree of liver cell injury， and protected the acute liver injury induced by CCl4. The ZZP high-dose group had a better effect than the ZZP low-dose group. In terms of the subacute liver injury， the levels of ALT， AST， MDA，TNF-α and IL-6 in the model group were significantly increased （P<0.01）， while the activity of liver SOD was significantly decreased （P<0.01）. As compared with the model group， liver Hyp content in the ZZP high-dose and low-dose groups was significantly decreased （P<0.01）， and the collagen deposition in liver of both groups was significantly reduced. The ZZP high-dose group also significantly down-regulated the mRNA expressions of α-SMA， Col1a1， Col3a1， FN， and Tgfbr2 in the liver of mice （P<0.05， P<0.01）. ConclusionZZP effectively protects the acute and subacute liver injury induced by CCl4， and the protective effect is proportional to its concentration. The mechanism may be related to the increase of the activity of antioxidant enzymes in the liver tissue， the decrease of the level of lipid peroxidation， and the inhibition of inflammatory response， thus reducing collagen deposition and improving early liver fibrosis.

Suppression of insulin-induced gene 1 (INSIG1) function promotes hepatic lipid remodelling and restrains NASH progression.

OBJECTIVE: Non-alcoholic fatty liver disease (NAFLD) is a silent pandemic associated with obesity and the metabolic syndrome, and also increases cardiovascular- and cirrhosis-related morbidity and mortality. A complete understanding of adaptive compensatory metabolic programmes that modulate non-alcoholic steatohepatitis (NASH) progression is lacking. METHODS AND RESULTS: Transcriptomic analysis of liver biopsies in patients with NASH revealed that NASH progression is associated with rewiring of metabolic pathways, including upregulation of de novo lipid/cholesterol synthesis and fatty acid remodelling. The modulation of these metabolic programmes was achieved by activating sterol regulatory element-binding protein (SREBP) transcriptional networks; however, it is still debated whether, in the context of NASH, activation of SREBPs acts as a pathogenic driver of lipotoxicity, or rather promotes the biosynthesis of protective lipids that buffer excessive lipid accumulation, preventing inflammation and fibrosis. To elucidate the pathophysiological role of SCAP/SREBP in NASH and wound-healing response, we used an Insig1 deficient (with hyper-efficient SREBPs) murine model challenged with a NASH-inducing diet. Despite enhanced lipid and cholesterol biosynthesis, Insig1 KO mice had similar systemic metabolism and insulin sensitivity to Het/WT littermates. Moreover, activating SREBPs resulted in remodelling the lipidome, decreased hepatocellular damage, and improved wound-healing responses. CONCLUSIONS: Our study provides actionable knowledge about the pathways and mechanisms involved in NAFLD pathogenesis, which may prove useful for developing new therapeutic strategies. Our results also suggest that the SCAP/SREBP/INSIG1 trio governs transcriptional programmes aimed at protecting the liver from lipotoxic insults in NASH.

AMPK-mTOR-ULK1-mediated autophagy protects carbon tetrachloride-induced acute hepatic failure by inhibiting p21 in rats.

Autophagy is a lysosomal-dependent degradation pathway in eukaryotic cells. Recent studies have reported that autophagy can facilitate the activation of hepatic stellate cells (HSCs) and fibrogenesis of the liver during long-term carbon tetrachloride (CCl4) exposure. However, little is known about the role of autophagy in CCl4-induced acute hepatic failure (AHF). This study aimed to identify whether modulation of autophagy can affect CCl4-induced AHF and evaluate the upstream signaling pathways mediated by CCl4-induced autophagy in rats. The accumulation of specific punctate distribution of endogenous LC3-II, increased expression of LC3-II, Atg5, and Atg7 genes/proteins, and decreased expression of p62 gene were observed after acute liver injury was induced by CCl4 in rats, indicating that CCl4 resulted in a high level of autophagy. Moreover, loss of autophagic function by using chloroquine (CQ, an autophagic inhibitor) aggravated liver function, leading to increased expression of p21 (a cyclin-dependent kinase inhibitor) in CCl4-treated rats. Furthermore, the AMPK-mTORC1-ULK1 axis was found to serve a function in CCl4-induced autophagy. These results reveal that AMPK-mTORC1-ULK1 signaling-induced autophagy has a protective role in CCl4-induced hepatotoxicity by inhibiting the p21 pathway. This study suggests a useful strategy aimed at ameliorating CCl4-induced acute hepatotoxicity by autophagy.

Lack of Mof reduces acute liver injury by enhancing transcriptional activation of Igf1.

Acute liver injury (ALI) is a rapid pathological process that may cause severe liver disease and may even be life-threatening. During ALI, the function of males absent on the first (MOF) has not yet been elucidated. In this study, we unveiled the expression pattern of MOF during carbon tetrachloride (CCl4 )-induced ALI and role of MOF in the regulation of liver regeneration. In the process of ALI, MOF is significantly overexpressed in the liver injury area. Knockdown of Mof attenuated CCl4 -induced ALI, and promoted liver cell proliferation, hepatic stellate cell activation and aggregation to the injured area, and liver fibrosis. Simultaneously, overexpression of Mof aggravated liver dysfunction caused by ALI. By directly binding to the promoter, MOF suppressed the transcriptional activation of Igf1. Knockdown of Mof promotes the expression of Igf1 and activates the Insulin-like growth factor 1 signaling pathway in the liver. Through this pathway, Knockdown of Mof reduces CCl4 -induced ALI and promotes liver regeneration. Our results provide the first demonstration for MOF contributing to ALI. Further understanding of the role of MOF in ALI may lead to new therapeutic strategies for ALI.

Carbon tetrachloride suppresses ER-Golgi transport by inhibiting COPII vesicle formation on the ER membrane in the RLC-16 hepatocyte cell line.

Carbon tetrachloride (CCl4 ) causes hepatotoxicity in mammals, with its hepatocytic metabolism producing radicals that attack the intracellular membrane system and destabilize intracellular vesicle transport. Inhibition of intracellular transport causes lipid droplet retention and abnormal protein distribution. The intracellular transport of synthesized lipids and proteins from the endoplasmic reticulum (ER) to the Golgi apparatus is performed by coat complex II (COPII) vesicle transport, but how CCl4 inhibits COPII vesicle transport has not been elucidated. COPII vesicle formation on the ER membrane is initiated by the recruitment of Sar1 protein from the cytoplasm to the ER membrane, followed by that of the COPII coat constituent proteins (Sec23, Sec24, Sec13, and Sec31). In this study, we evaluated the effect of CCl4 on COPII vesicle formation using the RLC-16 rat hepatocyte cell line. Our results showed that CCl4 suppressed ER-Golgi transport in RLC-16 cells. Using a reconstituted system of rat liver tissue-derived cytoplasm and RLC-16 cell-derived ER membranes, CCl4 treatment inhibited the recruitment of Sar1 and Sec13 from the cytosolic fraction to ER membranes. CCl4 -induced changes in the ER membrane accordingly inhibited the accumulation of COPII vesicle-coated constituent proteins on the ER membrane, as well as the formation of COPII vesicles, which suppressed lipid and protein transport between the ER and Golgi apparatus. Our data suggest that CCl4 inhibits ER-Golgi intracellular transport by inhibiting COPII vesicle formation on the ER membrane in hepatocytes.

Protective effects of honey and bee venom against lipopolysaccharide and carbon tetrachloride-induced hepatoxicity and lipid peroxidation in rats.

In the present study, the protective effects of honey and bee venom (BV) either independently or in combination against lipopolysaccharide (LPS) and carbon tetrachloride (CCl4)-induced hepatoxicity, lipid peroxidation, and hematological alterations in male albino rats were investigated. In addition, histopathological alterations of hepatic tissues induced by LPS/CCL4 were recorded. Sixty-four of male albino rats of average weight 120-150 g were included in this study. Rats were divided into eight equal groups of eight. The obtained results demonstrated that treatment with LPS/CCl4 caused an increase in the levels of alpha-fetoprotein, which was accompanied by changes in the hepatic function biomarkers that characterized by the increased levels of transaminases (AST, ALT). The results showed oxidative stress as assigned by the increase in lipid peroxide. Meantime detraction in the antioxidants, including glutathione peroxidase was observed. Interruptions in biochemical parameters accompanied by disturbances in hematological parameters and liver histopathology were resulted due to exposure to LPS/CCl4. This study showed the use of honey and BV provided a protective effect on hepatotoxicity induced by LPS/CCl4. This might have been occurred through the reduction of hepatic transaminases and the "Alpha-fetoprotein" in serum and the equilibration of the antioxidation system, thereby, inhibiting the reactive oxygen species accumulation. Honey and BV administration reestablish disturbed hematological parameters and liver histopathology persuaded by LPS/CCl4. More interesting, we demonstrated that using a combination of the honey and BV showed promising enhancement in their protective effects over the use of just one of the two reagents.

Novel hepatotoxicity biomarkers of extracellular vesicle (EV)-associated miRNAs induced by CCl4.

Recent findings have revealed that extracellular vesicles (EVs) are secreted from cells and circulate in the blood. EVs are classified as exosomes (40-100 nm), microvesicles (50-1,000 nm) or apoptotic bodies (500-2,000 nm). EVs contain mRNAs, microRNAs, and DNAs and have the ability to transfer them from cell to cell. Recently, especially in humans, the diagnostic accuracy of tumor cell type-specific EV-associated miRNAs as biomarkers has been found to be more than 90 %. In addition, microRNAs contained in EVs in blood are being identified as specific biomarkers of chemical-induced inflammation and organ damage. Therefore, microRNAs contained in the EVs released into the blood from tissues and organs in response to adverse events such as exposure to chemical substances and drugs are expected to be useful as novel biomarkers for toxicity assessment. In this study, C57BL/6 J male mice orally dosed with carbon tetrachloride (CCl4) were used as a hepatotoxicity animal model. Here, we report that not only the known hepatotoxicity biomarkers miR-122 and miR-192 but also 42 novel EV-associated biomarkers were upregulated in mice dosed with CCl4. Some of these novel biomarkers may be expected to be able to use for better understanding the mechanism of toxicity. These results suggest that our newly developed protocol using EV-associated miRNAs as a biomarker would accelerate the rapid evaluation of toxicity caused by chemical substances and/or drugs.

Indole-3-Carbinol Derivative DIM Mitigates Carbon Tetrachloride-Induced Acute Liver Injury in Mice by Inhibiting Inflammatory Response, Apoptosis and Regulating Oxidative Stress.

3,3'-Diindolylmethane (DIM), a metabolic product of indole-3-carbinol extracted from cruciferous vegetables exhibits anti-inflammatory and anti-cancer properties. Earlier, the product has been demonstrated to possess anti-fibrotic properties; however, its protective effects on liver injury have not been clearly elucidated. In this study, we postulated the effects and molecular mechanisms of action of DIM on carbon tetrachloride (CCl4)-induced liver injury in mice. Acute liver injury was induced by a single intraperitoneal administration of CCl4 (1 ml/kg) into mice. DIM was injected via subcutaneous route for three days at various doses (2.5, 5 and 10 mg/kg) before CCl4 injection. Mice were sacrificed and serum was collected for quantification of serum transaminases. The liver was collected and weighed. Treatment with DIM significantly reduced serum transaminases levels (AST and ALT), tumor necrosis factor-α (TNF-α) and reactive oxygen species (ROS). CCl4- induced apoptosis was inhibited by DIM treatment by the reduction in the levels of cleaved caspase-3 and Bcl2 associated X protein (Bax). DIM treated mice significantly restored Cytochrome P450 2E1, nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression in CCl4 treated mice. In addition, DIM downregulated overexpression of hepatic nuclear factor kappa B (NF-κB) and inhibited CCl4 mediated apoptosis. Our results suggest that the protective effects of DIM against CCl4- induced liver injury are due to the inhibition of ROS, reduction of pro-inflammatory mediators and apoptosis.

Establishment of non-alcoholic steatohepatitis mouse model induced by Western diet combined with low-dose carbon tetrachloride / 上海交通大学学报（医学版）

Objective • To construct a non-alcoholic steatohepatitis (NASH) mouse model by the combination of Western diet (WD) and low-dose carbon tetrachloride (CCl4), and explore the time nodes of typical NASH pathological changes. Methods • Male 8-week C57BL/6 mice were fed WD and intraperitoneally injected with CCl4 at a dose of 2 μL/g of body weight per week to construct NASH models. At different time points, the fasting blood glucose, and the levels of triacylglyceride, glutamic-pyruvic transaminase and glutamic-oxaloacetic transaminase were tested; glucose tolerance was tested at the 24th week. Besides, the liver index was calculated and oil red O staining, Sirius red staining, hematoxylin-eosin staining and TUNEL test were conducted to evaluate liver pathological changes after liver sampling. Results • Between the control group and model group, there was no significant difference in fasting blood glucose and glucose tolerance test result, while the significant differences of liver index were observed at the 8th, 12th and 24th week (P<0.05). And at the 24th week, the levels of triacylglyceride, glutamic-pyruvic transaminase and glutamic-oxaloacetic transaminase were higher in the model group than those in the control group (P<0.05). According to the results of oil red O staining, Sirius red staining, hematoxylin-eosin staining and TUNEL test, in the model group, a large amount of small lipid droplets accumulation in the liver tissues was detected and hepatocytes were mainly in apoptotic state at the 8th week; large lipid droplets, hepatocellular ballooning and spot-like necrosis were observed, and hepatocyte apoptosis persisted at the 16th week; stage 3 fibrosis of liver was observed, and the number of spot-like necrosis increased but lipid droplets decreased, while hepatocytes were mainly in a proliferative state at the 24th week. Conclusion • The mouse model of NASH can be established successfully by WD combined with low-dose CCl4, which can simulate the pathologic features of NASH in a short time.

Diallyl sulfide ameliorates carbon tetrachloride-induced hepatotoxicity in rats via suppressing stress-activated MAPK signaling pathways.

The underlined effects of diallyl sulfide (DAS) against CCL4 -induced oxidative, inflammatory, and apoptotic acute hepatic damage were assessed. Administration of DAS (50, 100, and 200 mg/kg) along with CCL 4 effectively mitigated serum aspartate aminotransferase, alanine aminotransferase activities, MDA, TNF-α, IL-1ß, and MCP-1 levels, as well as significantly restored HO-1, GSH levels and SOD activity in liver tissues compared with those in rats treated with CCL 4 . Moreover, DAS inhibited CCL 4 -induced increase of liver NF-κB (p65), Bax, p38 MAPK, and JNK protein expression. In addition, DAS accelerated protein expression of Nrf2 and Bcl-2. The hepatoprotective properties of DAS were further confirmed by the reduced severity of hepatic damage as demonstrated by histopathological findings. In conclusion, DAS achieved its protective potential against CCL4-induced hepatotoxicity through antiapoptotic activity, as well as the synchronized modulation of NF-κB and Nrf2 for the favor of antioxidant/anti-inflammatory effects via suppression of the upstream stress-activated MAPKs pathways.

Sirtuin3 deficiency exacerbates carbon tetrachloride-induced hepatic injury in mice.

Sirtuin3 (SIRT3) plays an important role in maintaining normal mitochondrial function and alleviating oxidative stress. After carbon tetrachloride (CCl4 ) administration, the expression of SIRT3 decreased in the liver of mice, which indicated that the SIRT3 might play a crucial role during chemical-induced acute hepatic injury. To verify the hypothesis, CCl 4 was given to induce acute hepatic injury in SIRT3 knockout (KO) mice and wild-type (WT) mice. CCl 4 -induced liver injury was more severe in SIRT3 KO mice compared with the WT mice. In addition, the oxidative stress induced by CCl 4 was enhanced in the SIRT3 KO mice. Furthermore, the increased expression of dynamin-related protein 1 was also aggravated in SIRT3 KO mice after CCl 4 administration. In conclusion, our study demonstrated that SIRT3 deficiency exacerbated CCl 4 -induced impairment of the liver in mice, and the mechanism might be related to enhanced oxidative stress.

Changes of CCl4-induced of Liver Injury in Rats for 24 Hours / 中国实验方剂学杂志

Objective:To replicate the animal model of liver injury in rats by using carbon tetrachloride (CCl4), investigate the dynamic changes of early biomarkers of liver injury, namely glutamate dehydrogenase (GLDH), purine nucleotide phosphorylase(PNP), α-dynamic changes of glutathione-S-transferase (α-GST) and arginase 1(Arg1), and provide experimental evidence for early detection of acute liver injury. Method:Forty-eight Wistar rats were randomly divided into a blank group and a model group. The model group was intraperitoneally injected with 10 mL·kg-1 10% CCl4 olive oil solution, fasting but except water. Animals were sacrificed at 3, 6, 12, and 24 h. The serum liver function alanine aminotransferase(ALT), aspartate aminotransferase (AST), bilirubin (TBIL), alkaline phosphatase (ALP) levels, α-GST, Arg1, GLDH, PNP levels, and liver homogenate superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA) levels were then detected. Result:As compared with blank group, the levels of ALT, AST, TBIL, α-GST, Arg1, GLDH, PNP and MDA were increased significantly 3 h after administration, and SOD was decreased significantly(Pα-GST, ARG-, GLDH, TBIL, ALP and MDA were increased significantly, while GSH and SOD were decreased significantly (PPα-GST, Arg1, TBIL, ALP and MDA were significantly increased, while GSH and SOD were significantly decreased (PConclusion:α-GST, Arg1, GLDH and PNP have better sensitivity than traditional liver function test indicators, and can be used for early detection of liver injury induced by CCl4 in rats.