Protective effect of recombinant human IL-1Ra on CCl4-induced acute liver injury in mice

Pituitary-derived small extracellular vesicles promote liver repair by its cargo miR-143-3p

The small Extracellular vesicles (sEV) has been recognized to be significant for intercellular communication due to their ability to transfer important cellular cargoes like miRNAs through circulation. The pituitary gland has not been clearly known about the role of its secreted sEV under normal physiological conditions. And Liver disease is a global public health burden. The present study is the first to investigate the effect of pituitary sEV on the liver. Sequencing and qRT-PCR revealed miR-143-3p is one of the richest in the pituitary sEV. MiR-143 Knockout (KO) mice resulted in a remarkable decrease in insulin-like growth factor 1 (IGF-1) levels and a significant increase in insulin-like growth factor binding protein 5 (IGFBP5) levels along with a reduction in liver primary cell growth. More importantly, compared with miR-143-KO-sEV, WT-sEV possesses a more robust capacity to improve miR-143 KO mice liver repair through the Wnt/β-catenin pathway after an acute injury caused by carbon tetrachloride (CCl4). Our results indicate that pituitary-derived sEV promotes hepatocyte proliferation and liver repair by its cargo miR-143-3p and provides new insight into the regulation mechanism of the pituitary-liver axis, and open a new window for endocrine regulation by using sEV.

Hepatocytes-derived Prdx1 regulates macrophage phenotypes via TLR4 activation in acute liver injury

Acute liver injury (ALI) is a significant causative factor for multiple hepatic diseases. The excessive inflammatory response triggers proinflammatory immune cells recruitment, infiltration and differentiation, further contributing to inflammatory injuries in liver. As a proinflammatory factor, circulating Peroxiredoxin 1 (Prdx1) is elevated in ALI patients and mice. In this study, through carbon tetrachloride (CCl4) and cecal puncture and ligation (CLP)-induced liver injury mice model, we found hepatocytes-derived Prdx1 expression was increased in ALI. After AAV8-Prdx1-mediated Prdx1 knockdown, CCl4 and CLP-induced ALI was alleviated, along with the reduced proinflammatory cytokines, suppressed myeloid cells recruitment, decreased proportions of hepatic macrophages and neutrophils, restrained proinflammatory macrophage differentiation and infiltration. Mechanistically, hepatocyte-derived Prdx1 regulated macrophages through paracrine activation of the TLR4 signal. Our data support the immune and inflammatory regulatory role of Prdx1 in ALI pathological process to suggest its potential therapeutic application and clinical value.

Protective and immunomodulatory effects of mesenchymal stem cells on multiorgan injury in male rats with heatstroke

Heatstroke (HS) causes multiple organ dysfunction syndrome (MODS) with a mortality rate of 60% after hospitalization. Currently, there is no effective and targeted approach for the treatment of HS. Despite growing evidence that mesenchymal stem cells (MSCs) may reduce multiorgan damage and improve survival through immunomodulatory effects in several diseases, no one has tested whether MSCs have immunomodulatory effects in heatstroke. The present study focused on pathological changes and levels of the cytokines and immunoglobulins to investigate the mechanisms underlying the protective effect and the anti-inflammatory effects of MSCs. We found that MSCs treatment significantly reduced the 28-day mortality rate (P < 0.05), the levels of hepatic and renal function markers on day 1 (P < 0.01) and the pathological lesion scores of multiple organs in HS rats. The levels of IgG1, IgM, and IgA of the HS + MSC group was significantly higher than that in HS group on days 3 and 28(P < 0.05). In conclusion, MSCs contribute to protecting against multiorgan injury, reducing pro-inflammatory cytokines, stabilizing immunoglobulins, and reducing the mortality rate of HS rats.

Castanopsis sieboldii Extract Alleviates Acute Liver Injury by Antagonizing Inflammasome-Mediated Pyroptosis

Castanopsis sieboldii (CS), a subtropical species, was reported to have antioxidant and antibacterial effects. However, the anti-inflammatory effects of CS have not been studied. This study aimed to investigate whether the 70% ethanol extract of the CS leaf (CSL3) inhibited lipopolysaccharide (LPS)-induced inflammatory responses and LPS and ATP-induced pyroptosis in macrophages. CSL3 treatment inhibited NO release and iNOS expression in LPS-stimulated cells. CSL3 antagonized NF-κB and AP-1 activation, which was due to MAPK (p38, ERK, and JNK) inhibition. CSL3 successfully decreased NLRP3 inflammasome activation and increased IL-1β expression. CSL3 treatment diminished LPS and ATP-induced pore formation in GSDMD. The in vivo effect of CSL3 on acute liver injury was evaluated in a CCl4-treated mouse model. CCl4 treatment increased the activity of serum alanine aminotransferase and aspartate aminotransferase, which decreased by CSL3. In addition, CCl4-induced an increase in TNF-α, and IL-6 levels decreased by CSL3 treatment. Furthermore, we verified that the CCl4-induced inflammasome and pyroptosis-related gene expression in liver tissue and release of IL-1β into serum were suppressed by CSL3 treatment. Our results suggest that CSL3 protects against acute liver injury by inhibiting inflammasome formation and pyroptosis.

Biofabricated Palladium Nanoparticle-Decorated Reduced Graphene Oxide Nanocomposite Using the Punica granatum (Pomegranate) Peel Extract: Investigation of Potent In Vivo Hepatoprotective Activity against Acetaminophen-Induced Liver Injury in Wistar Albino Rats

Acute acetaminophen (APAP) toxicity is a predominant clinical problem, which causes serious liver injury in both humans and experimental animals. This study presents the histological and biochemical factor and antioxidant enzyme level changes induced by an acute acetaminophen overdose in Wistar albino rat livers to elucidate the effective hepatoprotective potential of biofabricated palladium nanoparticle-decorated reduced graphene oxide nanocomposites (rGO/PdNPs-NC) compared to silymarin. After detailed characterization of the hepatoprotective potential of the synthesized rGO/PdNPs-NC, the rats were divided into eight groups (n = 6): control group (normal saline, 1 mL/kg b.w.), silymarin, Punica granatum (pomegranate) peel extract, PdNPs, reduced graphene oxide (rGO-PG), and reduced graphene oxide palladium nanocomposites (rGO/PdNPs-NC, low and high doses) for 7 successive days. The acetaminophen (APAP)-treated group was administered a single dose of acetaminophen (2 g/kg b.w.) on the 8th day. The histopathological results showed that the acetaminophen overdose group exhibited massive intrahepatic hemorrhagic necrosis around the centrilobular region with hepatocytes with vacuolization and swollen cytoplasm found in the liver architecture. This hepatopotential was further assessed by various biochemical parameters such as SGOT, SGPT, ALB, ALP, LDH, direct bilirubin, total bilirubin, and total protein. Also, the antioxidant parameters such as SOD, CAT, MDA, GSH, GRD, and GST were assayed. Rats of groups 7 and 8 showed a significant decrease in SGOT, SGPT, ALP, LDH, direct bilirubin, and total bilirubin (p < 0.001), while a significant increase in the final total protein and ALB as compared to group 2 rats (p < 0.001) was observed. The antioxidant parameters exhibited that rats of groups 7 and 8 showed a significant (p < 0.001) increase in the level of SOD, CAT, GSH, GRD, and GST without affecting the MDA as compared to group 2 rats. Also, the hepatoprotective potential of rGO/PdNPs-NC (low and high doses) was comparable to that of the standard reference drug silymarin. The present study reveals that the rGO/PdNPs-NC possesses significant hepatoprotective activity and acts as an effective and promising curative agent against acetaminophen-induced hepatotoxicity.

Protective Effects of Sophorae tonkinensis Gagnep. (Fabaceae) Radix et Rhizoma Water Extract on Carbon Tetrachloride-Induced Acute Liver Injury

Sophorae tonkinensis Radix et Rhizoma (STR) is a traditional Chinese herbal medicine. STR can reduce aminotransferase activity; however, the specific mechanism remains unclear. Here, we explored the potential therapeutic effects and hepatoprotective mechanism of STR on liver damage in mice. The chemical characteristics of the extract were characterized using ultra-high-performance liquid chromatography-tandem mass spectrometry fingerprinting, and its antioxidant capacity was verified using free radical scavenging tests. Forty-eight Kunming mice were randomly assigned into six groups. The model was made after the corresponding drug was given. The results showed that the STR water extract pretreatment significantly reduced serum aminotransferase and related liver function indicators compared with that in the model group. Furthermore, the STR water extract pretreatment significantly inhibited the apoptosis of liver cells, the level of liver high-mobility group box 1 (HMGB1), and inflammatory factors in hepatic tissue compared with that in the model group, and significantly downregulated the levels of toll-like receptor 4 (TLR4), Myeloid differentiation factor 88 (MyD88), and nuclear factor kappa B (NF-κB) compared with those in the model group. Overall, the STR water extract exerted a significant protective effect on CCL₄-induced acute liver injury in this study, and the accurate active ingredients of the STR water extract will be explored in the near future.

Riboflavin ameliorates mitochondrial dysfunction via the AMPK/PGC1α/HO‑1 signaling pathway and attenuates carbon tetrachloride‑induced liver fibrosis in rats

Hepatic fibrosis is a global health problem, with increasing evidence demonstrating that oxidative stress serves a pivotal role in fibrogenesis. Riboflavin is a vital nutrient in the human and animal diet, which enhances the activity of antioxidant enzymes and ameliorates oxidative stress. The present study evaluated the effect of riboflavin on liver fibrosis and the mechanisms underlying this process. Rats were subcutaneously injected with carbon tetrachloride (CCl₄) dissolved in sterile olive oil twice per week to induce hepatic fibrosis. The effect of riboflavin on CCl₄-induced liver fibrosis was then assessed. Blood samples and liver tissues were collected and analyzed. The liver tissue morphological changes, immunohistochemical analysis, levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in the mitochondria, and the protein expression levels of α-smooth muscle actin (α-SMA), transforming growth factor-β1 (TGF-β1), extracellular signal-regulated kinase (ERK), p38, c-Jun N-terminal kinase (JNK), AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and heme oxygenase 1 (HO-1) in the liver were also analyzed. The results demonstrated that riboflavin treatment significantly decreased the levels of alanine transaminase and aspartate transaminase in the serum, increased SOD activity and modulated the MDA level in the mitochondria. Furthermore, riboflavin significantly inhibited the CCl₄-induced, upregulated protein expression levels of phosphorylated (p)-ERK, p-p38, p-JNK, TGF-β1 and α-SMA. Moreover, riboflavin significantly increased the expression of p-AMPK, PGC-1α and HO-1 in the liver tissue. These results suggested that riboflavin delays CCl₄-induced hepatic fibrosis by enhancing the mitochondrial function via the AMPK/PGC-1α/HO-1 and mitogen-activated protein kinase signaling pathways.

Multi-faceted role of pyroptosis mediated by inflammasome in liver fibrosis

Liver fibrosis is a reversible pathological overreaction during the self-repair of liver injuries, and it is the common period of chronic liver diseases induced by different pathogenesis progress into cirrhosis and even hepatocellular carcinoma. Pyroptosis, a novel form of programmed cell death, is reported to take part in the pathogenesis and progression of acute or chronic liver diseases and liver fibrosis. Caspase-1 dependent canonical pathway and caspase-4/-5/-11 mediated noncanonical pathway are the two signalling pathways to induce pyroptosis. The activation of inflammasomes under the stimulation of pathogenic microorganisms and danger signals can initiate the pyroptotic pathway and release large amounts of proinflammatory and profibrotic cytokines. This article comprehensively summarizes recent researches focused on the mechanism of pyroptosis and its role in major hepatic cells, which can provide potential therapeutic strategies for liver fibrosis.

Role of the Inflammasome in Liver Disease

The involvement of inflammasomes in the proinflammatory response observed in chronic liver diseases, such as alcohol-associated liver disease (ALD) and nonalcoholic fatty liver disease (NAFLD), is widely recognized. Although there are different types of inflammasomes, most studies to date have given attention to NLRP3 (nucleotide-binding oligomerization domain-like receptor family, pyrin domain containing 3) in the pathogenesis of ALD, NAFLD/nonalcoholic steatohepatitis, and fibrosis. Canonical inflammasomes are intracellular multiprotein complexes that are assembled after the sensing of danger signals and activate caspase-1, which matures interleukin (IL)-1β, IL-18, and IL-37 and also induces a form of cell death called pyroptosis. Noncanonical inflammasomes activate caspase-11 to induce pyroptosis. We discuss the different types of inflammasomes involved in liver diseases with a focus on (a) signals and mechanisms of inflammasome activation, (b) the role of different types of inflammasomes and their products in the pathogenesis of liver diseases, and (c) potential therapeutic strategies targeting components of the inflammasomes or cytokines produced upon inflammasome activation.

A study on setting standards for near-infrared fluorescence-image guided surgery (NIRFGS) time lapse monitoring based on preoperative liver function assessment

Background

This study aimed to explore the relationship between the fluorescence intensity of indocyanine green (ICG) in near-infrared fluorescence guided surgery (NIRFGS) and preoperative liver function indicators.

Methods

A total of 12 4T1 tumor-bearing mice were used for model establishment. Intraperitoneal injection (i.p.) of 20% carbon tetrachloride (CCl₄) corn oil solution (50 µL) was given to mice in the liver injury model group, 24 hours after injection, the model was established, while the control group received 0% CCl₄ corn oil solution (50 µL) (n=6 for each group). Additionally, doses of 8 mg/kg and 1 mg/kg of free ICG were injected intravenously (i.v.) (n=3 in each group). Fluorescence was imaged in vivo using an NIR fluorescence imaging system at different time points (1, 2, 4, 8, 12, 24, 48, and 72 h) after injection.

Results

The absolute fluorescence intensity of mice in the liver injury model group was stronger than that in the control group. Mice in the liver injury model group had the same clearance rate of ICG from the tumor as normal mice. However, the background clearance rate was slower than that of normal mice, which prolonged the optimal tumor to background ratio (TBR) time. Correlation analysis was also used to determine which preoperative liver function parameters were most correlated with hepatic ICG clearance.

Conclusions

Liver injury does not significantly affect the maximum TBR, but prolongs the optimal TBR time, and at the same time, a wider and more stable surgical window will appear. This study showed that a prolonged surgical start time is feasible according to preoperative liver function testing using NIR fluorescence imaging technology.

Orphan nuclear receptor ERRγ regulates hepatic TGF-β2 expression and fibrogenic response in CCl4-induced acute liver injury

Acute liver injury results from the complex interactions of various pathological processes. The TGF-β superfamily plays a crucial role in orchestrating fibrogenic response. In contrast to TGF-β1, a role of TGF-β2 in hepatic fibrogenic response has not been fully investigated. In this study, we showed that TGF-β2 gene expression and secretion are induced in the liver of CCl₄ (1 ml/kg)-treated WT mice. Studies with hepatocyte specific ERRγ knockout mice or treatment with an ERRγ-specific inverse agonist, GSK5182 (40 mg/kg), indicated that CCl₄-induced hepatic TGF-β2 production is ERRγ dependent. Moreover, IL6 was found as upstream signal to induce hepatic ERRγ and TGF-β2 gene expression in CCl₄-mediated acute toxicity model. Over-expression of ERRγ was sufficient to induce hepatic TGF-β2 expression, whereas ERRγ depletion markedly reduces IL6-induced TGF-β2 gene expression and secretion in vitro and in vivo. Promoter assays showed that ERRγ directly binds to an ERR response element in the TGF-β2 promoter to induce TGF-β2 transcription. Finally, GSK5182 diminished CCl₄-induced fibrogenic response through inhibition of ERRγ-mediated TGF-β2 production. Taken together, these results firstly demonstrate that ERRγ can regulate the TGF-β2-mediated fibrogenic response in a mouse model of CC1₄-induced acute liver injury.

Govaniadine Ameliorates Oxidative Stress, Inflammation, and Kupffer Cell Activation in Carbon Tetrachloride-Induced Hepatotoxicity in Rats

Liver diseases such as hepatic carcinoma are one of the main health problems worldwide. Herbal drugs are largely used to treat liver injury in the indigenous system of medicine and may provide lead compounds for hepatoprotective drug discovery. The present study is investigated to test the Corydalis govaniana Wall. extract, fraction, and isolate therapeutically active constituents to explore their hepatoprotective, anti-inflammatory, and antioxidant activities. For this purpose, the antioxidant activity of govaniadine, caseadine, caseamine, and protopine was performed by assessing the scavenging events of the stable 2,2-diphenyl-1-picrylhydrazyl. Hepatoprotection of govaniadine was assessed in terms of reduction in serum enzymes (alanine aminotransferase, aspartate transaminase, and alkaline phosphatase) caused by CCl₄-induced liver injury in rats and by histopathological techniques. All the compounds showed significant antioxidant activity with a percentage inhibition of 92.2, 86.7, 85.3, and 79.7, respectively, compared to propyl gallate 90.3%. Treatment with govaniadine reduced the serum enzyme level down to normal levels in the CCl₄-treated group while inhibiting the increase of malondialdehyde, and the induction of superoxide dismutase and the glutathione level was upregulated. Histopathology showed ∼47% damage to the liver cells in the CCl₄-treated group; reduction in this damaged area was found to be better upon using govaniadine. Immunohistochemistry results showed that govaniadine as compared to silymarin has exceedingly decreased the inflammation by halting the CCl₄-induced activation of hepatic macrophages. In carrageenan-induced paw edema assay, govaniadine significantly alleviated the edema after 1-5 h at a dose of 20 mg/kg (26.00 and 28.5%), 50 mg/kg (22.05 and 27.0%), and 100 mg/kg (20.02 and 25.30%), respectively. The results of our experiments suggest that govaniadine showed antioxidant and hepatoprotective activity in liver injury. The hepatoprotective function of govaniadine may be associated to the scavenging of the free radical and attenuation of oxidative stress as well as inflammatory responses in the liver. Hence, govaniadine may be a lead compound for the hepatoprotective drug discovery process and further research is needed to find out their molecular mechanism of protection.

Bone Marrow Plasma Cytokine Signature Profiles in Severe Aplastic Anemia

OBJECTIVE

We studied bone marrow plasma (BMP) cytokines in severe aplastic anemia (SAA) patients and healthy volunteers to investigate differences in the cytokine profiles between them and propose a cytokine signature of SAA.

METHODS

A Bio-Plex suspension array system was used to measure 27 analytes in BMP samples from 47 SAA patients and 30 healthy donors.

RESULTS

Compared to healthy people, SAA patients had higher levels of tumor necrosis factor α (TNF-α (TNF-γ (IFN-γ (IFN-β (MIP-1β (MIP-1α (TNF-α (TNF-β (MIP-1β (MIP-1β (MIP-1γ (IFN-α (TNF.

CONCLUSIONS

The current study demonstrated distinct cytokine profiles among untreated SAA patients, recovering SAA (RSAA) patients, and healthy people. The cytokines of RSAA patients showed similar characteristics to those of untreated SAA patients and healthy people, respectively, which may reflect that the immune status of RSAA patients is in different stages of recovery after IST; thus, it may provide an important tool in diagnosing and evaluating or predicting curative effects in clinics.

Pelargonidin ameliorates acetaminophen-induced hepatotoxicity in mice by inhibiting the ROS-induced inflammatory apoptotic response

The common analgesic acetaminophen (N-acetyl-p-aminophenol, APAP) is non-toxic to the liver at therapeutic doses. However, an overdose of APAP can lead to APAP-induced liver failure, which has emerged as a serious issue in the US and Europe. Pelargonidin is an anthocyanidin found in pomegranates, plums, and various berries. Pelargonidin has strong antioxidant effects, directly scavenging superoxide radicals and inhibiting H₂O₂-induced lipid peroxidation. Focusing on these effects, we studied the preventative effect of pelargonidin on APAP-induced hepatotoxicity and its underlying mechanisms in vivo. We observed that pelargonidin mitigates serum alanine aminotransferase and aspartate aminotransferase activity, which are strongly associated with APAP-induced hepatotoxicity. We also found that pelargonidin reduced APAP-induced hepatic necrosis by removing excessive ROS. Hepatic necrosis stimulates the release of molecular pathogens that induce inflammation, which increases cell stress and can lead to apoptosis. Therefore, pelargonidin was able to reduce levels of necrosis, inflammation, and hepatocyte apoptosis. These results indicate that the administration of pelargonidin protects against APAP-induced hepatotoxicity and that it could be a novel protective strategy against APAP-induced liver failure.

Dietary zerumbone, a sesquiterpene, ameliorates hepatotoxin-mediated acute and chronic liver injury in mice

Acute liver injury (ALI) is a life-threatening clinical syndrome. Long-lasting liver injury can lead to chronic hepatic inflammation and fibrogenic responses. Zerumbone (ZER), the main constituent of rhizomes of Zingiber zerumbet Smith, has a variety of functions including anticancer activity. We investigated the role of ZER on the progression of hepatotoxin-induced liver injury. Single or repeated injection of CCl₄ was used to induce acute or chronic liver injury, respectively. Mice were orally administered with ZER (10, 50 mg/kg) during the experimental period. Histopathologic analysis and serum biochemical levels revealed that ZER had hepatoprotective activities against ALI. Similar effects of ZER on injured livers were confirmed by analyses of inflammation and apoptosis-related genes. Western blot analysis showed that protein levels of apoptotic molecules were decreased, whereas antiapoptotic protein levels were conversely increased in injured livers treated with ZER. Furthermore, chronic liver injury and its associated fibrogenesis in mice were reduced by ZER treatment. These findings from our in vivo experiments further indicate that ZER could alleviate hepatocellular toxicity and inhibit activation of primary hepatic stellate cells. Our results suggest that ZER might have potential as a safe and prophylactic alternative to prevent acute and chronic liver injury.

Interleukin-1 Receptor Antagonist Modulates Liver Inflammation and Fibrosis in Mice in a Model-Dependent Manner

Background: Interleukin-1 (IL-1)β and IL-1 receptor antagonist (IL-1Ra) have been proposed as important mediators during chronic liver diseases. We aimed to determine whether the modulation of IL-1β signaling with IL-1Ra impacts on liver fibrosis. Methods: We assessed the effects of IL-1β on human hepatic stellate cells (HSC) and in mouse models of liver fibrosis induced by bile duct ligation (BDL) or carbon tetrachloride treatment (CCl-4). Results: Human HSCs treated with IL-1β had increased IL-1β, IL-1Ra, and MMP-9 expressions in vitro. HSCs treated with IL-1β had reduced α-smooth muscle actin expression. These effects were all prevented by IL-1Ra treatment. In the BDL model, liver fibrosis and Kuppfer cell numbers were increased in IL-1Ra KO mice compared to wild type mice and wild type mice treated with IL-1Ra. In contrast, after CCl-4 treatment, fibrosis, HSC and Kupffer cell numbers were decreased in IL-1Ra KO mice compared to the other groups. IL-1Ra treatment provided a modest protective effect in the BDL model and was pro-fibrotic in the CCl-4 model. Conclusions: We demonstrated bivalent effects of IL-1Ra during liver fibrosis in mice. IL-1Ra was detrimental in the CCl-4 model, whereas it was protective in the BDL model. Altogether these data suggest that blocking IL-1-mediated inflammation may be beneficial only in selective liver fibrotic disease.

Hepatic cell sheets engineered from human mesenchymal stem cells with a single small molecule compound IC-2 ameliorate acute liver injury in mice

INTRODUCTION

We previously reported that transplantation of hepatic cell sheets from human bone marrow-derived mesenchymal stem cells (BM-MSCs) with hexachlorophene, a Wnt/β-catenin signaling inhibitor, ameliorated acute liver injury. In a further previous report, we identified IC-2, a newly synthesized derivative of the Wnt/β-catenin signaling inhibitor ICG-001, as a potent inducer of hepatic differentiation of BM-MSCs.

METHODS

We manufactured hepatic cell sheets by engineering from human BM-MSCs using the single small molecule IC-2. The therapeutic potential of IC-2-induced hepatic cell sheets was assessed by transplantation of IC-2- and hexachlorophene-treated hepatic cell sheets using a mouse model of acute liver injury.

RESULTS

Significant improvement of liver injury was elicited by the IC-2-treated hepatic cell sheets. The expression of complement C3 was enhanced by IC-2, followed by prominent hepatocyte proliferation stimulated through the activation of NF-κB and its downstream molecule STAT-3. Indeed, IC-2 also enhanced the expression of amphiregulin, resulting in the activation of the EGFR pathway and further stimulation of hepatocyte proliferation. As another important therapeutic mechanism, we revealed prominent reduction of oxidative stress mediated through upregulation of the thioredoxin (TRX) system by IC-2-treated hepatic cell sheets. The effects mediated by IC-2-treated sheets were superior compared with those mediated by hexachlorophene-treated sheets.

CONCLUSION

The single compound IC-2 induced hepatic cell sheets that possess potent regeneration capacity and ameliorate acute liver injury.

Chloroquine ameliorates carbon tetrachloride-induced acute liver injury in mice via the concomitant inhibition of inflammation and induction of apoptosis

This is the first study to investigate the hepatoprotective effect of CQ on acute liver injury caused by carbon tetrachloride (CCl₄) in a murine model and the underlying molecular mechanisms. Ninety-six mice were randomly divided into the control (n = 8), CQ (n = 8), CCl₄ (n = 40), and CCl₄ + CQ (n = 40) treatment groups. In the CCl₄ group, mice were intraperitoneally (i.p) injected with 0.3% CCl₄ (10 mL/kg, dissolved in olive oil); in the CCl₄ + CQ group, mice were i.p injected with CQ at 50 mg/kg at 2, 24, and 48 h before CCl₄ administration. The mice in the control and CQ groups were administered with an equal vehicle or CQ (50 mg/kg). Mice were killed at 2, 6, 12, 24, 48 h post CCl₄ treatment and their livers were harvested for analysis. The results showed that CQ pre-treatment markedly inhibited CCl₄-induced acute liver injury, which was evidenced by decreased serum transaminase, aspartate transaminase and lower histological scores of liver injury. CQ pretreatment downregulated the CCl₄-induced hepatic tissue expression of high-mobility group box 1 (HMGB1) and the levels of serum HMGB1 as well as IL-6 and TNF-α. Furthermore, CQ pre-treatment inhibited autophagy, downregulated NF-kB expression, upregulated p53 expression, increased the ratio of Bax/Bcl-2, and increased the activation of caspase-3 in hepatic tissue. This is the first study to demonstrate that CQ ameliorates CCl₄-induced acute liver injury via the inhibition of HMGB1-mediated inflammatory responses and the stimulation of pro-apoptotic pathways to modulate the apoptotic and inflammatory responses associated with progress of liver damage.

Effects of microRNA-217 on proliferation, apoptosis, and autophagy of hepatocytes in rat models of CCL4-induced liver injury by targeting NAT2

Liver injury is an important cause of serious liver disease. This study aims to explore the effects of miR-217 targeting NAT2 on hepatocyte proliferation, apoptosis, and autophagy following carbon tetrachloride (CCL4)-induced liver injury. Rat models of CCL4-induced liver injury were established. Healthy Wistar rats were randomized into the normal, blank, negative control (NC), microRNA-217 (miR-217) mimic, miR-217 inhibitor, small interfering RNA (siRNA)-N-acetyltransferase 2 (NAT2), and miR-217 inhibitor + siRNA-NAT2 groups. NAT2 activity was evaluated with reversed-phase high-performance liquid chromatographic method. Immunohistochemistry was used to detect NAT2 protein positive rate. Reverse transcription quantitative polymerase chain reaction and western blot analysis were used to examine expressions of miR-217, NAT2, Bcl-2, Bax, p35, LC3-II, Becline-1, and the ratio of caspase-3/cleaved caspase-3. Autophagy, proliferation, and cell cycle distribution were determined by electron microscope, CCK-8, and flow cytometry. NAT2 protein positive rate and miR-217, NAT2, Bcl-2, and p35 expressions were higher and Bax, LC3-II, and Becline-1 expressions and the ratio of caspase-3/cleaved caspase-3 lower in the normal group than the other six groups. Compared with the blank and NC groups, in the miR-217 mimic and siRNA-NAT2 groups, Bax, LC3-II, and Becline-1 expressions and the ratio of caspase-3/cleaved caspase-3, and hepatocyte apoptosis and autophagy increased, while NAT2, Bcl-2, and p35 expressions and hepatocyte proliferation decreased; opposite results were observed in the miR-217 inhibitor group. Collectively, miR-217 targeting NAT2 inhibits proliferation and promotes apoptosis and autophagy of hepatocytes in CCL4-induced liver injury.

In vivo multiphoton kinetic imaging of the toxic effect of carbon tetrachloride on hepatobiliary metabolism

We used intravital multiphoton microscopy to study the recovery of hepatobiliary metabolism following carbon tetrachloride (CCl4) induced hepatotoxicity in mice. The acquired images were processed by a first order kinetic model to generate rate constant resolved images of the mouse liver. We found that with progression of hepatotoxicity, the spatial gradient of hepatic function disappeared. A CCl4-induced damage mechanism involves the compromise of membrane functions, resulting in accumulation of processed 6-carboxyfluorescein molecules. At day 14 following induction, a restoration of the mouse hepatobiliary function was found. Our approach allows the study of the response of hepatic functions to chemical agents in real time and is useful for studying pharmacokinetics of drug molecules through optical microscopic imaging.

The hepatoprotective effect of the probiotic Clostridium butyricum against carbon tetrachloride-induced acute liver damage in mice

Previous studies have revealed that the probiotic Clostridium butyricum (C. butyricum) can attenuate cirrhosis in chronic non-alcoholic liver disease. However, the effects of C. butyricum on acute liver injury (ALI) remain unclear. Therefore, the present study aims to examine the hepatoprotective effects and the underlying mechanisms employed by C. butyricum in a carbon tetrachloride (CCl₄)-induced ALI murine model. Here, we evaluated the survival rate and the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), anti-oxidants, cytokines and the gut microbiota to elucidate the potential mechanisms by which C. butyricum is hepatoprotective. Our results show that five days of prophylactic C. butyricum treatment significantly reduced mortality by 40% and decreased the CCl₄-induced levels of ALT and AST in the serum of these mice. Additionally, prophylactic treatment with C. butyricum increased the activity of both superoxide dismutase (SOD) and catalase (CAT), and substantially reduced malondialdehyde (MDA) levels, which were deteriorated in the untreated ALI mice compared to normal control mice. Furthermore, C. butyricum up-regulated the nuclear factor (erythroid-derived 2)-like 2 (NRF2) content. CCl₄-induced mice also exhibited considerable increases of phosphorylation of nuclear factor-kappa B (NF-κB) p65 and pro-inflammatory cytokines, including interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). However, the inflammatory responses of the liver induced by CCl₄ were significantly alleviated by C. butyricum pretreatment. Additionally, we found that interleukin-10 (IL-10), an anti-inflammatory mediator, was increased in the C. butyricum-pretreated group. Microbiota analysis in these mice revealed crosstalk between the gut microbial metabolites and ALI. The intestinal flora was changed by CCl₄ administration and was shifted by the probiotic C. butyricum toward more beneficial bacteria, particularly the Clostridia orders, which are the known producers of the anti-inflammatory and anti-oxidative metabolite butyrate. In conclusion, we found that the intestinal flora changes after the intraperitoneal injection of CCl₄. We also offer novel insights into the mechanism by which probiotic C. butyricum pretreatment alleviates the CCl₄-induced inflammation and oxidative stress of the liver via the modulation of NRF2, NF-κB p65, IL-10 and the intestinal microbiota in mice.

Modulation of immune responses in lentiviral vector-mediated gene transfer

Lentiviral vectors (LV) are widely used vehicles for gene transfer and therapy in pre-clinical animal models and clinical trials with promising safety and efficacy results. However, host immune responses against vector- and/or transgene-derived antigens remain a major obstacle to the success and broad applicability of gene therapy. Here we review the innate and adaptive immunological barriers to successful gene therapy, both in the context of ex vivo and in vivo LV gene therapy, mostly concerning systemic LV delivery and discuss possible means to overcome them, including vector design and production and immune modulatory strategies.

Curcumin Attenuates on Carbon Tetrachloride-Induced Acute Liver Injury in Mice via Modulation of the Nrf2/HO-1 and TGF-β1/Smad3 Pathway

This study aimed to investigate the protective effect of curcumin against carbon tetrachloride (CCl₄)-induced acute liver injury in a mouse model, and to explain the underlying mechanism. Curcumin at doses of 50, 100 and 200 mg/kg/day were administered orally once daily for seven days prior to CCl₄ exposure. At 24 h, curcumin-attenuated CCl₄ induced elevated serum transaminase activities and histopathological damage in the mouse's liver. Curcumin pre-treatment at 50, 100 and 200 mg/kg significantly ameliorated CCl₄-induced oxidative stress, characterized by decreased malondialdehyde (MDA) formations, and increased superoxide dismutase (SOD), catalase (CAT) activities and glutathione (GSH) content, followed by a decrease in caspase-9 and -3 activities. Curcumin pre-treatment significantly decreased CCl₄-induced inflammation. Furthermore, curcumin pre-treatment significantly down-regulated the expression of TGF-β1 and Smad3 mRNAs (both p < 0.01), and up-regulated the expression of nuclear-factor erythroid 2-related factor 2 (Nrf2) and HO-1 mRNA (both p < 0.01) in the liver. Inhibition of HO-1 attenuated the protective effect of curcumin on CCl₄-induced acute liver injury. Given these outcomes, curcumin could protect against CCl₄-induced acute liver injury by inhibiting oxidative stress and inflammation, which may partly involve the activation of Nrf2/HO-1 and inhibition of TGF-β1/Smad3 pathways.

Astilbin from Smilax glabra Roxb. Attenuates Inflammatory Responses in Complete Freund's Adjuvant-Induced Arthritis Rats

Astilbin, a flavonoid compound, was isolated from the rhizome of Smilax glabra Roxb. (with red cross-section) grown in Guizhou Province, China. We accessed its effect and potential mechanism on attenuation of the inflammatory response in CFA-induced AA rats. Our results showed that daily oral administration of astilbin at 5.3 mg/kg reduced joint damage in the hind paw of AA rats. Accordingly, astilbin exhibited remarkable inhibitory effects on TNF-α, IL-1β, and IL-6 mRNA expression. Significant decrease of serum cytokine levels of TNF-α, IL-1β, and IL-6 was also observed in astilbin-treated AA rats compared to the vehicle-treated AA rats. The reduced expression of these cytokines was associated with protein activity suppression of three key molecular targets in the pathogenesis of RA, including IKKβ, NF-κB p65 subunit, and TLR adaptor MyD88. Furthermore, the therapeutic effects of astilbin on the inhibition of cytokines production as well as the reduction of inflammatory response in AA rats are close to a commonly used antirheumatic drug, leflunomide. Collectively, our data suggest that the action mechanism of astilbin, as an anti-inflammatory agent for RA treatment, is associated with modulating the production of proinflammatory cytokines and inhibiting the expression of key elements in NF-κB signaling pathway mediated by TLR.

Effects of exogenous thymosin β4 on carbon tetrachloride-induced liver injury and fibrosis

The present study investigated the effects of exogenous thymosin β4 (TB4) on carbon tetrachloride (CCl₄)-induced acute liver injury and fibrosis in rodent animals. Results showed that both in mice and rats CCl₄ rendered significant increases in serum alanine aminotransferase and aspartate aminotransferase, hepatic malondialdehyde formation, decreases in antioxidants including superoxide dismutase and glutathione, and up-regulated expressions of transforming growth factor-β1, α-smooth muscle actin, tumor necrosis factor-α and interleukin-1β in the liver tissues. Hydroxyproline contents in the rat livers were increased by CCl₄. Histopathological examinations indicated that CCl₄ induced extensive necrosis in mice livers and pseudo-lobule formations, collagen deposition in rats livers. However, all these changes in mice and rats were significantly attenuated by exogenous TB4 treatment. Furthermore, up-regulations of nuclear factor-κB p65 protein expression by CCl₄ treatment in mice and rats livers were also remarkably reduced by exogenous TB4 administration. Taken together, findings in this study suggested that exogenous TB4 might prevent CCl₄-induced acute liver injury and subsequent fibrosis through alleviating oxidative stress and inflammation.

Proliferation‑inhibiting pathways in liver regeneration (Review)

Liver regeneration, an orchestrated process, is the primary compensatory mechanism following liver injury caused by various factors. The process of liver regeneration consists of three stages: Initiation, proliferation and termination. Proliferation‑promoting factors, which stimulate the recovery of mitosis in quiescent hepatocytes, are essential in the initiation and proliferation steps of liver regeneration. Proliferation‑promoting factors act as the 'motor' of liver regeneration, whereas proliferation inhibitors arrest cell proliferation when the remnant liver reaches a suitable size. Certain proliferation inhibitors are also expressed and activated in the first two steps of liver regeneration. Anti‑proliferation factors, acting as a 'brake', control the speed of proliferation and determine the terminal point of liver regeneration. Furthermore, anti‑proliferation factors function as a 'steering‑wheel', ensuring that the regeneration process proceeds in the right direction by preventing proliferation in the wrong direction, as occurs in oncogenesis. Therefore, proliferation inhibitors to ensure safe and stable liver regeneration are as important as proliferation‑promoting factors. Cytokines, including transforming growth factor‑β and interleukin‑1, and tumor suppressor genes, including p53 and p21, are important members of the proliferation inhibitor family in liver regeneration. Certain anti‑proliferation factors are involved in the process of gene expression and protein modification. The suppression of liver regeneration led by metabolism, hormone activity and pathological performance have been reviewed previously. However, less is known regarding the proliferation inhibitors of liver regeneration and further investigations are required. Detailed information regarding the majority of known anti‑proliferation signaling pathways also remains fragmented. The present review aimed to understand the signalling pathways that inhbit proliferation in the process of liver regeneration.

Protective effect of Xuebijing injection on D-galactosamine- and lipopolysaccharide-induced acute liver injury in rats through the regulation of p38 MAPK, MMP-9 and HO-1 expression by increasing TIPE2 expression

Xuebijing injection (XBJ) has long been used to treat infectious diseases in China. The therapeutic effect of XBJ is probably associated with anti-inflammatory effects. However, the precise mechanisms responsible for the effects of XBJ remain unknown. The present study was conducted in order to evaluate the protective effects of XBJ in a rat model of D-galactosamine (D-Gal)- and lipopolysaccharide (LPS)-induced acute liver injury. In the present study, the rats were injected with D-Gal and LPS intraperitoneally to induce acute liver injury. Two hours prior to D-Gal and LPS administration, the treatment group was administered XBJ by intravenous infusion. The effects of XBJ on D-Gal- and LPS-induced expression of tumor necrosis factor (TNF)-alpha-induced protein 8-like 2 (TIPE2), nuclear factor-κB (NF-κB), matrix metalloproteinase-9 (MMP-9) and heme oxygenase-1 (HO-1) as well as mitogen-activated protein kinase (MAPK) signaling was examined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blot analysis, immunofluorescence, as well as by analysing the serum levels of pro-inflammatory cytokines and the transaminases, alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Myeloperoxidase (MPO), malondialdehyde (MDA) and superoxide dismutase (SOD) levels in the rat liver tissues were also measured. For histological analysis, hematoxylin and eosin (H&E)-stained liver samples were evaluated. The results showed that XBJ upregulated TIPE2 and HO-1 expression, reduced the expression of NF-κB65 and MMP-9, inhibited the LPS-induced gene expression of c-jun N-terminal kinase (JNK) and p38 MAPK, decreased the generation of pro-inflammatory cytokines [interleukin (IL)-6, IL-13 and TNF-α], inhibited ALT and AST activity, and ameliorated D-Gal- and LPS-induced liver injury. The histological results also demonstrated that XBJ attenuated D-Gal- and LPS-induced liver inflammation. It was found that XBJ may prevent LPS-induced pro-inflammatory gene expression through inhibiting the NF-κB and MAPK signaling pathways by upregulating TIPE2 expression, thereby attenuating LPS-induced liver injury in rats. The marked protective effects of XBJ suggest that it has the potential to be used in the treatment of LPS-induced liver injury.

Involvement of matrix metalloproteinases (MMPs) and inflammasome pathway in molecular mechanisms of fibrosis

Fibrosis is a basic connective tissue lesion defined by the increase in the fibrillar extracellular matrix (ECM) components in tissue or organ. Matrix metalloproteinases (MMPs) are a major group of proteases known to regulate the turn-over of ECM and so they are suggested to be important in tissue remodelling observed during fibrogenic process associated with chronic inflammation. Tissue remodelling is the result of an imbalance in the equilibrium of the normal processes of synthesis and degradation of ECM components markedly controlled by the MMPs/TIMP imbalance. We previously showed an association of the differences in collagen deposition in the lungs of bleomycin-treated mice with a reduced molar pro-MMP-9/TIMP-1 ratio. Using the carbon tetrachloride (CCl₄) preclinical model of liver fibrosis in mice, we observed a significant increase in collagen deposition with increased expression and release of tissue inhibitors of metalloproteinase (TIMP)-1 both at 24 h and 3 weeks later. This suggests an early altered regulation of matrix turnover involved in the development of fibrosis. We also demonstrated an activation of NLRP3-inflammasome pathway associated with the IL-1R/MyD88 signalling in the development of experimental fibrosis both in lung and liver. This was also associated with an increased expression of purinergic receptors mainly P2X₇. Finally, these observations emphasize those effective therapies for these disorders must be given early in the natural history of the disease, prior to the development of tissue remodelling and fibrosis.

The Role of IL-1 Family Members and Kupffer Cells in Liver Regeneration

Interleukin-1 (IL-1) family and Kupffer cells are linked with liver regeneration, but their precise roles remain unclear. IL-1 family members are pleiotropic factors with a range of biological roles in liver diseases, inducing hepatitis, cirrhosis, and hepatocellular carcinoma, as well as liver regeneration. Kupffer cells are the main source of IL-1 and IL-1 receptor antagonist (IL-1Ra), the key members of IL-1 family. This systemic review highlights a close association of IL-1 family members and Kupffer cells with liver regeneration, although their specific roles are inconclusive. Moreover, IL-1 members are proposed to induce effects on liver regeneration through Kupffer cells.

Establishment of a new animal model of azithromycin-induced liver injury and study the molecular pathological change during the process

The purpose of the present study is to establish a new animal model of azithromycin (AZ)-induced liver injury and study the molecular pathological change during the process. First, mice were respectively injected intraperitoneally with AZ of different high doses. Our results showed that 800 mg/kg AZ injection significantly induced liver injury in the mice, which reflected an ideal process of liver injury and repair. In this study, we analyzed the molecular pathological changes during the process by hematoxylin and eosin staining, immunohistochemistry, Western blot, and quantitative real-time reverse transcription polymerase chain reaction in the liver of mice at 0, 12, 24, 48, and 72 h after 800 mg/kg injection. Our results showed that the expression of heat shock protein 70, proliferating cell nuclear antigen, vascular endothelial growth factor, caspase 3, and cytochrome P450 2E1 were significantly differently expressed during liver injury induced by 800 mg/kg AZ in mice. Our results will be conducive for further study of the pathogenesis and prevention of drug-induced liver injury.

Dihydromyricetin alleviates carbon tetrachloride-induced acute liver injury via JNK-dependent mechanism in mice

AIM: To assess the effects of dihydromyricetin (DHM) as a hepatoprotective candidate in reducing hepatic injury and accelerating hepatocyte proliferation after carbon tetrachloride (CCl₄) treatment.

METHODS: C57 BL/6 mice were used in this study. Mice were orally administered with DHM (150 mg/kg) for 4 d after CCl₄ treatment. Serum and liver tissue samples were collected on days 1, 2, 3, 5 and 7 after CCl₄ treatment. The anti-inflammatory effect of DHM was assessed directly by hepatic histology detection and indirectly by serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin, and superoxide dismutase (SOD). Inflammatory cytokines, such as interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α), were detected using ELISA kits. Proliferating cell nuclear antigen (PCNA) staining was used to evaluate the role of DHM in promoting hepatocyte proliferation. Hepatocyte apoptosis was measured by TUNEL assay. Furthermore, apoptosis proteins Caspases-3, 6, 8, and 9 were detected by Western blot. SP600125 were used to confirm whether DHM regulated liver regeneration through JNK/TNF-α pathways.

RESULTS: DHM showed a strong anti-inflammatory effect on CCl₄-induced liver injury in mice. DHM could significantly decrease serum ALT, AST, IL-1β, IL-6 and TNF-α and increase serum albumin, SOD and liver SOD compared to the control group after CCl₄ treatment (P < 0.05). PCNA results indicated that DHM could significantly increase the number of PCNA positive cells compared to the control (348.9 ± 56.0 vs 107.1 ± 31.4, P < 0.01). TUNEL assay showed that DHM dramatically reduced the number of apoptotic cells after CCl₄ treatment compared to the control (365.4 ± 99.4 vs 90.5±13.8, P < 0.01). Caspase activity detection showed that DHM could reduce the activities of Caspases- 8, 3, 6 and 9 compared to the control (P < 0.05). The results of Western blot showed that DHM increased the expression of JNK and decreased TNF-α expression. However, DHM could not affect TNF-α expression after SP600125 treatment. Furthermore, DHM could significantly improve the survival rate of acute liver failure (ALF) mice (73.3% vs 20.0%, P < 0.0001), and SP600125 could inhibit the effect of DHM.

CONCLUSION: These findings demonstrate that DHM alleviates CCl₄-induced liver injury, suggesting that DHM is a promising candidate for reversing liver injury and ALF.

Role of the sympathetic nervous system in carbon tetrachloride-induced hepatotoxicity and systemic inflammation

Carbon tetrachloride (CCl₄) is widely used as an animal model of hepatotoxicity and the mechanisms have been arduously studied, however, the contribution of the sympathetic nervous system (SNS) in CCl₄-induced acute hepatotoxicity remains controversial. It is also known that either CCl₄ or SNS can affect systemic inflammatory responses. The aim of this study was to establish the effect of chemical sympathectomy with 6-hydroxydopamine (6-OHDA) in a mouse model of CCl₄-induced acute hepatotoxicity and systemic inflammatory response. Mice exposed to CCl₄ or vehicle were pretreated with 6-OHDA or saline. The serum levels of aminotransferases and alkaline phosphatase in the CCl₄-poisoning mice with sympathetic denervation were significantly lower than those without sympathetic denervation. With sympathetic denervation, hepatocellular necrosis and fat infiltration induced by CCl₄ were greatly decreased. Sympathetic denervation significantly attenuated CCl₄-induced lipid peroxidation in liver and serum. Acute CCl₄ intoxication showed increased expression of inflammatory cytokines/chemokines [eotaxin-2/CCL24, Fas ligand, interleukin (IL)-1α, IL-6, IL-12p40p70, monocyte chemoattractant protein-1 (MCP-1/CCL2), and tumor necrosis factor-α (TNF-α)], as well as decreased expression of granulocyte colony-stimulating factor and keratinocyte-derived chemokine. The overexpressed levels of IL-1α, IL-6, IL-12p40p70, MCP-1/CCL2, and TNF-α were attenuated by sympathetic denervation. Pretreatment with dexamethasone significantly reduced CCl₄-induced hepatic injury. Collectively, this study demonstrates that the SNS plays an important role in CCl₄-induced acute hepatotoxicity and systemic inflammation and the effect may be connected with chemical- or drug-induced hepatotoxicity and circulating immune response.

Hepatoprotective and urease inhibitory activities of garlic conjugated gold nanoparticles

Garlic conjugated gold nanoparticles were successfully synthesized and their hepatoprotective potential was determined in a CCl₄-induced acute hepatic injury model.

Neutralization of ADAM8 ameliorates liver injury and accelerates liver repair in carbon tetrachloride-induced acute liver injury

Although some studies have described the function of ADAM8 (a disintegrin and metalloprotease 8) related with rheumatoid arthritis, cancer and asthma, etc., the concrete role of ADAM8 in acute liver injury is still unknown. So mice respectively received anti-ADAM8 monoclonal antibody (mAb) of 100 μg/100 μl, 200 μg/100 μl or 300 μg/100 μl in PBS or PBS pre-injection. Then acute liver injury was induced in the mice by intraperitoneal (i.p.) injection of carbon tetrachloride (CCl₄). Serum AST and ALT level, Haematoxylin-eosin (H&E) staining, the expression level of vascular endothelial growth factor (VEGF), cytochrome P450 1A2 (CYP1A2) and proliferating cell nuclear antigen (PCNA) were detected in the mice after CCl4 administration. Our results showed that anti-ADAM8 mAb pre-injection could effectively lower AST and ALT levels (P < 0.05 or P < 0.01) and reduce liver injury (P < 0.05 or P <0.01), induce the expression of VEGF, CYP1A2 and PCNA (P <0.05 or P < 0.01) in dose-dependent manner compared with the control mice which received PBS pre-injection. In summary, our study suggested that ADAM8 might promote liver injury by inhibiting the proliferation of hepatocytes, angiogenesis and affecting the metabolism function of liver during acute liver injury induced by CCl₄. Anti-ADAM8 mAb injection might be suitable as a potential method for acute liver injury therapy.

High-sensitivity C-reactive protein and interleukin-6-dominant inflammation and ischemic stroke risk: the northern Manhattan study

BACKGROUND AND PURPOSE

Interleukin-6 (IL-6) is a proinflammatory cytokine with known autoregulatory feedback mechanisms. We hypothesized that elevated high-sensitivity C-reactive protein (hsCRP) relative to IL-6 confers an increased risk of ischemic stroke (IS), and low hsCRP relative to IL-6 a decreased risk, for individuals in the prospective, multiethnic, population-based Northern Manhattan Study (NOMAS).

METHODS

Serum hsCRP and IL-6 were measured in NOMAS participants at baseline. We created a trichotomized predictor based on the dominant biomarker in terms of quartiles: hsCRP-dominant, IL-6-dominant, and codominant groups. Cox proportional hazards models were used to calculate hazard ratios and 95% confidence intervals for the association between inflammatory biomarker group status and risk of incident IS.

RESULTS

Of 3298 participants, both hsCRP and IL-6 were available in 1656 participants (mean follow-up, 7.8 years; 113 incident IS). The hsCRP-dominant group had increased risk of IS (adjusted hazard ratio, 2.62; 95% confidence interval, 1.56-4.41) and the IL-6-dominant group had decreased risk (adjusted hazard ratio, 0.38; 95% confidence interval, 0.18-0.82) when compared with the referent group, after adjusting for potential confounders. Model fit was improved using the inflammation-dominant construct, over either biomarker alone.

CONCLUSIONS

In this multiethnic cohort, when hsCRP-quartile was higher than IL-6 quartile, IS risk was increased, and conversely when IL-6 quartiles were elevated relative to hsCRP, IS risk was decreased. Construct validity requires confirmation in other cohorts.

Proper heat shock pretreatment reduces acute liver injury induced by carbon tetrachloride and accelerates liver repair in mice

Whether proper heat shock preconditioning can reduce liver injury and accelerate liver repair after acute liver injury is worth study. So mice received heat shock preconditioning at 40°C for 10 minutes (min), 20 min or 30 min and recovered at room temperature for 8 hours (h) under normal feeding conditions. Then acute liver injury was induced in the heat shock-pretreated mice and unheated control mice by intraperitoneal (i.p.) injection of carbon tetrachloride (CCl₄). Hematoxylin and eosin (H&E) staining, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and the expression levels of heat shock protein 70 (HSP70), cytochrome P450 1A2 (CYP1A2) and proliferating cell nuclear antigen (PCNA) were detected in the unheated control mice and heat shock-pretreated mice after CCl₄ administration. Our results showed that heat shock preconditioning at 40°C for 20 min remarkably improved the mice’s survival rate (P<0.05), lowered the levels of serum AST and ALT (P<0.05), induced HSP70 (P<0.01), CYP1A2 (P<0.01) and PCNA (P<0.05) expression, effectively reduced liver injury (P<0.05) and accelerated the liver repair (P<0.05) compared with heat shock preconditioning at 40°C for 10 min or 30 min in the mice after acute liver injury induced by CCl₄ when compared with the control mice. Our results may be helpful in further investigation of heat shock pretreatment as a potential clinical approach to target liver injury

mTOR signaling in liver regeneration: Rapamycin combined with growth factor treatment

AIM: To investigate the effects of mammalian target of rapamycin (mTOR) inhibition on liver regeneration and autophagy in a surgical resection model.

METHODS: C57BL/6 mice were subjected to a 70% partial hepatectomy (PH) and treated intraperitoneally every 24 h with a combination of the mTOR inhibitor rapamycin (2.5 mg/kg per day) and the steroid dexamethasone (2.0 mg/kg per day) in phosphate buffered saline (PBS) or with PBS alone as vehicle control. In the immunosuppressant group, part of the group was treated subcutaneously 4 h prior to and 24 h after PH with a combination of human recombinant interleukin 6 (IL-6; 500 μg/kg per day) and hepatocyte growth factor (HGF; 100 μg/kg per day) in PBS. Animals were sacrificed 2, 3 or 5 d after PH and liver tissue and blood were collected for further analysis. Immunohistochemical staining for 5-Bromo-2’-deoxyuridine (BrdU) was used to quantify hepatocyte proliferation. Western blotting was used to detect hepatic microtubule-associated protein 1 light chain 3 (LC3)-II protein expression as a marker for autophagy. Hepatic gene expression levels of proliferation-, inflammation- and angiogenesis-related genes were examined by real-time reverse transcription-polymerase chain reaction and serum bilirubin and transaminase levels were analyzed at the clinical chemical core facility of the Erasmus MC-University Medical Center.

RESULTS: mTOR inhibition significantly suppressed regeneration, shown by decreased hepatocyte proliferation (2% vs 12% BrdU positive hepatocyte nuclei at day 2, P < 0.01; 0.8% vs 1.4% at day 5, P = 0.02) and liver weight reconstitution (63% vs 76% of initial total liver weight at day 3, P = 0.04), and furthermore increased serum transaminase levels (aspartate aminotransferase 641 U/L vs 185 U/L at day 2, P = 0.02). Expression of the autophagy marker LC3-II, which was reduced during normal liver regeneration, increased after mTOR inhibition (46% increase at day 2, P = 0.04). Hepatic gene expression showed an increased inflammation-related response [tumor necrosis factor (TNF)-α 3.2-fold upregulation at day 2, P = 0.03; IL-1Ra 6.0-fold upregulation at day 2 and 42.3-fold upregulation at day 5, P < 0.01] and a reduced expression of cell cycle progression and angiogenesis-related factors (HGF 40% reduction at day 2; vascular endothelial growth factor receptor 2 50% reduction at days 2 and 5; angiopoietin 1 60% reduction at day 2, all P≤ 0.01). Treatment with the regeneration stimulating cytokine IL-6 and growth factor HGF could overcome the inhibitory effect on liver weight (75% of initial total liver weight at day 3, P = 0.02 vs immunosuppression alone and P = 0.90 vs controls) and partially reversed gene expression changes caused by rapamycin (TNF-α and IL-1Ra levels at day 2 were restored to control levels). However, no significant changes in hepatocyte proliferation, serum injury markers or autophagy were found.

CONCLUSION: mTOR inhibition severely impairs liver regeneration and increases autophagy after PH. These effects are partly reversed by stimulation of the IL-6 and HGF pathways.

Oroxylin A accelerates liver regeneration in CCl₄-induced acute liver injury mice

Introduction

Based on the previous research that oroxylin A can suppress inflammation, we investigated the hepatoprotective role of oroxylin A against CCl₄-induced liver damage in mice and then studied the possible alteration of the activities of cytokine signaling participating in liver regeneration. Wild type (WT) mice were orally administrated with oroxylin A (60 mg/kg) for 4 days after CCl₄ injection, the anti-inflammatory effects of oroxylin A were assessed directly by hepatic histology and indirectly by measuring serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and Albumin. Proliferating cell nuclear antigen (PCNA) staining was performed to evaluate the role of oroxylin A in promoting hepatocyte proliferation. Serum IL-1β, TNF-α, IL-6 and IL-1Ra levels were measured by enzyme-linked immunosorbent assay (ELISA) and liver HGF, EGF, TNF-α, IL-6, IL-1Ra and IL-1β gene expression was determined by quantitative real-time PCR. The data indicated that the IL-6 and TNF-α mRNA of oroxylin A administered group significantly increased higher than the control within 12 hours after CCl₄ treatment. Meanwhile, oroxylin A significantly enhanced the expression of IL-1Ra at the early phase, which indicated that oroxylin A could facilitate the initiating events in liver regeneration by increasing IL-1Ra which acts as an Acute-Phase Protein (APP). In addition, a lethal CCl₄-induced acute liver failure model offers a survival benefit in oroxylin A treated WT mice. However, oroxylin A could not significantly improve the percent survival of IL-1RI^−/− mice with a lethal CCl₄-induced acute liver failure.

Conclusions

Our study confirmed that oroxylin A could strongly promote liver structural remodeling and functional recovery through IL-1Ra/IL-1RI signaling pathway. All these results support the possibility of oroxylin A being a therapeutic candidate for acute liver injury.

Administration of IL-1Ra chitosan nanoparticles enhances the therapeutic efficacy of mesenchymal stem cell transplantation in acute liver failure

BACKGROUND AND AIMS

To investigate the synergistic effect of IL-1Ra administration and stem cell transplantation in swine suffering from acute liver failure (ALF), to elucidate the mechanism of IL-1Ra activity and to demonstrate mesenchymal stem cell (MSC) transplantation as a potential treatment for ALF.

METHODS

Thirty-five Chinese experimental mini-swine were divided into five groups randomly. Group A (n = 7) is the control group and all swine were injected with saline via portal veins. Group B (n = 7) received IL-1Ra via ear veins 6 h before receiving saline. Group C (n = 7) received MSC transplantation and all swine were injected with 8 × 10⁷ MSCs via portal veins. Group D (n = 7) swine were treated with a combination of IL-1Ra and MSC transplantation E (n = 7) also received a combined treatment of both IL-1Ra and bone marrow (BM-MSC) transplantation, except that the IL-1Ra was in the form of chitosan nanoparticles. Liver function, level of cytokines and liver pathological changes were measured in the following 4 weeks.

RESULTS

IL-1Ra chitosan nanoparticles exhibited controlled-release ability in PBS. Swine in Group E showed a significant improvement in inflammation environment, liver function and hepatocyte proliferation. Levels of hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) in Group E were elevated compared to other groups.

CONCLUSIONS

IL-1Ra chitosan nanoparticles showed significant liver targeting ability and controlled-release characteristics. Combined therapy with IL-1Ra chitosan nanoparticles and MCS transplantation exhibits great synergistic effects through paracrine function and suppression of inflammation.

Hepatoprotective effects of baicalein against CCl4-induced acute liver injury in mice

AIM: To investigate the hepatoprotective effect of baicalein against carbon tetrachloride (CCl₄)-induced liver damage in mice.

METHODS: Mice were orally administered with baicalein after CCl₄ injection, and therapeutic baicalein was given twice a day for 4 d. The anti-inflammation effects of baicalein were assessed directly by hepatic histology and serum alanine aminotranferease and aspartate aminotransferase measurement. Proliferating cell nuclear antigen was used to evaluate the effect of baicalein in promoting hepatocyte proliferation. Serum interleukin (IL)-6, IL-1β and tumor necrosis factor-α (TNF-α) levels were measured by enzyme-linked immunosorbent assay and liver IL-6, TNF-α, transforming growth factor-α (TGF-α), hepatocyte growth factor (HGF) and epidermal growth factor (EGF) genes expression were determined by quantitative real-time polymerase chain reaction.

RESULTS: CCl₄-induced acute liver failure model offers a survival benefit in baicalein-treated mice. The data indicated that the mRNA levels of IL-6 and TNF-α significantly increased within 12 h after CCl₄ treatment in baicalein administration groups, but at 24, 48 and 72 h, the expression of IL-6 and TNF-α was kept at lower levels compared with the control. The expression of TGF-α, HGF and EGF was enhanced dramatically in baicalein administration group at 12, 24, 48 and 72 h. Furthermore, we found that baicalein significantly elevated the serum level of TNF-α and IL-6 at the early phase, which indicated that baicalein could facilitate the initiating events in liver regeneration.

CONCLUSION: Baicalein may be a therapeutic candidate for acute liver injury. Baicalein accelerates liver regeneration by regulating TNF-α and IL-6 mediated pathways.

Impairment of α(2)-macroglobulin synthesis in experimental hepatopathic rats treated with turpentine oil

The aim of this study was to investigate the synthesis of α(2)-macroglobulin (α2M) in hepatopathic rats injected with turpentine oil to induce acute inflammation. Hepatopathy was induced by oral administration of acetaminophen at a dose of 1 g/kg daily for 2 weeks or a 25% solution of carbon tetrachloride (CCl(4)) at 2 ml/kg body weight three times per week for 7 weeks. Acute inflammation was induced by intramuscular injection of turpentine oil at a dose of 1.0 ml/kg body weight. Serum concentrations of α2M were measured by enzyme-linked immunosorbent assay. Aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and total protein differed significantly between acetaminophen or CCl(4)-induced hepatopathic rats and acetaminophen control (AA-control) or CCl(4) control (CC-control) rats. Furthermore, pathological examination confirmed hepatopathy in rat livers. Peak serum concentrations and area under the time-concentration curve for α2M showed significant differences between hepatopathic rats and AA-control or CC-control rats. Thus, serum concentrations of α2M did not increase when compared with nontreated rats.

Inflammasomes in liver diseases

Inflammation is a common element in the pathogenesis of most chronic liver diseases that lead to fibrosis and cirrhosis. Inflammation is characterized by activation of innate immune cells and production of pro-inflammatory cytokines IL-1α, IL-1β, and TNFα. Inflammasomes are intracellular multiprotein complexes expressed in both parenchymal and non-parenchymal cells of the liver that in response to cellular danger signals activate caspase-1, and release IL-1β and IL-18. The importance of inflammasome activation in various forms of liver diseases in relation to liver damage, steatosis, inflammation and fibrosis is discussed in this review.

Amniotic-fluid-derived mesenchymal stem cells overexpressing interleukin-1 receptor antagonist improve fulminant hepatic failure

Uncontrolled hepatic immunoactivation is regarded as the primary pathological mechanism of fulminant hepatic failure (FHF). The major acute-phase mediators associated with FHF, including IL-1β, IL-6, and TNF-α, impair the regeneration of liver cells and stem cell grafts. Amniotic-fluid–derived mesenchymal stem cells (AF-MSCs) have the capacity, under specific conditions, to differentiate into hepatocytes. Interleukin-1–receptor antagonist (IL-1Ra) plays an anti-inflammatory and anti-apoptotic role in acute and chronic inflammation, and has been used in many experimental and clinical applications. In the present study, we implanted IL-1Ra–expressing AF-MSCs into injured liver via the portal vein, using D-galactosamine–induced FHF in a rat model. IL-1Ra expression, hepatic injury, liver regeneration, cytokines (IL-1β, IL-6), and animal survival were assessed after cell transplantation. Our results showed that AF-MSCs over-expressing IL-1Ra prevented liver failure and reduced mortality in rats with FHF. These animals also exhibited improved liver function and increased survival rates after injection with these cells. Using green fluorescent protein as a marker, we demonstrated that the engrafted cells and their progeny were incorporated into injured livers and produced albumin. This study suggests that AF-MSCs genetically modified to over-express IL-1Ra can be implanted into the injured liver to provide a novel therapeutic approach to the treatment of FHF.

Plasma from patients with liver failure inhibits the proliferation of HepG2 cells

AIM: To explore the mechanisms by which plasma from patients with liver failure inhibits the proliferation of HepG2 cells and to evaluate whether epidermal growth factor (EGF) can reverse this inhibitory effect.

METHODS: Plasma samples were collected from three patients with acute-on-chronic liver failure during plasma exchange therapy and treated with heparin. After HepG2 cells were cultured in medium containing 50% plasma from patients with liver failure with or without EGF stimulation, cell proliferation and apoptosis were detected by methyl thiazolyl tetrazolium (MTT) assay and Hoechst staining, respectively. The expression of intracellular cyclin D1 and cyclin-dependent kinase 4 (CDK4) in HepG2 cells was examined by Western blotting.

RESULTS: Treatment with 50% plasma from patients with liver failure for 12 to 72 hours significantly inhibited the proliferation of HepG2 cells in a time-dependent manner when compared to cells cultured with 50% normal control plasma (NCP). EGF at a concentration of 5, 10 or 20 μg/L significantly induced the proliferation of HepG2 cells cultured with NCP, while only high-dose EGF (20 μg/L) showed a transient promotion to the proliferation of HepG2 cells cultured with plasma from patients with liver failure. After stimulation with 20 μg/L EGF, the proliferation was still significantly inhibited in cells cultured with patient plasma compared to those cultured with NCP. The presence of 50% patient plasma did not significantly alter apoptosis index of HepG2 cells (P > 0.05). The expression of intracellular cyclin D1 and CDK4 in HepG2 cells was obviously inhibited after treatment with patient plasma for 12 to 72 hours.

CONCLUSION: Plasma from patients with liver failure inhibits the proliferation of HepG2 cells possibly by down-regulating the expression of intracellular cyclin D1 and CDK4. EGF can not reverse this inhibitory effect.

Serum interleukin 1 receptor antagonist as an independent marker of non-alcoholic steatohepatitis in humans

BACKGROUND & AIMS

Mechanisms leading to non-alcoholic steatohepatitis (NASH) have remained unclear, and non-invasive diagnosis of NASH is challenging. In this study, we investigated the benefits of measuring serum interleukin 1 receptor antagonist (IL-1RA) levels.

METHODS

Liver biopsies from 119 morbidly obese individuals (47.5 ± 9.0 years, BMI 44.9 ± 5.9 kg/m(2)) were used for histological and gene expression assessment. In a cross-sectional population-based cohort of 6447 men (58 ± 7 years, BMI 27.0 ± 3.9 kg/m(2)) the association of serum IL1-RA with serum alanine aminotransferase (ALT) levels was investigated.

RESULTS

Serum levels of IL-1RA, and liver mRNA expression of IL1RN are associated with NASH and the degree of lobular inflammation in liver (p<0.05). The decrease in serum IL-1RA level and expression of IL1RN after obesity surgery correlated with the improvement of lobular inflammation (p<0.05). We developed a novel NAFLD Liver Inflammation Score, including serum Il-1RA concentration, which performed better to diagnose NASH than did previously published scores. Results from the population study confirmed the potential of measuring serum IL-1RA level. The strongest determinants of the ALT concentration at the population level were Matsuda insulin sensitivity index (r(2)=0.130, p=7 × 10(-197)) and serum IL-1RA concentration (r(2)=0.074, p=1 × 10(-110)). IL-1RA concentrations associated significantly with ALT levels even after adjusting for BMI, alcohol consumption and insulin sensitivity (p=2 × 10(-21)).

CONCLUSIONS

IL-1RA serum levels associate with liver inflammation and serum ALT independently of obesity, alcohol consumption and insulin resistance, suggesting a potential use of IL-1RA as a non-invasive inflammatory marker for NASH.

Expression of human glucocorticoid receptor in T lymphocytes in acute-on-chronic hepatitis B liver failure

BACKGROUND

Glucocorticoid receptor (GR) participates in the pathogenesis of liver inflammation. However, the potential role of GR in acute-on-chronic hepatitis B liver failure (ACHBLF) is still obscure.

AIM

This present study was aimed to determine peripheral GR expression in ACHBLF patients.

METHODS

Forty patients with ACHBLF, 20 patients with chronic hepatitis B (CHB) and 16 healthy controls were included in this retrospectively study. Flow cytometry was used to determine the peripheral expression of GR + T lymphocytes. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) was performed for assessing relative mRNA levels of GR alpha and beta isoforms in peripheral blood mononuclear cells. Serum cortisol level was evaluated using radioimmunoassay.

RESULTS

The serum cortisol level and the percentage of GR + T lymphocytes in ACHBLF patients were significantly decreased compared with CHB patients and healthy controls. However, there were no significant differences in mean fluorescence intensity (MFI) of GR + T lymphocytes within three groups. The relative GR alpha mRNA expression in ACHBLF patients was significant decreased compared with healthy controls. However, the relative GR beta mRNA expression in ACHBLF patients was significantly increased compared with CHB patients and healthy controls. In ACHBLF patients, the percentage of GR + T lymphocyte was significantly positively associated with relative GR alpha expression, prothrombin activity, and HBV DNA level, but negatively correlated with serum cortisol level and MELD score. Furthermore, the percentage of GR + T lymphocytes was also obviously elevated in survivors than non-survivors.

CONCLUSIONS

It was strongly suggested that GR play an important role in the pathogenesis of ACHBLF.

Role of early growth response 1 in liver injury

Liver injury is a sophisticated pathophysiological process caused by many factors. Currently, the role of early growth response 1 (EGR1) in liver injury is still controversial. Some studies show that EGR1 can amplify the systemic inflammatory response and promote apoptosis in galactosamine/lipopolysaccharide-induced acute liver injury and alpha-naphthylisothiocyanate (ANIT)-induced intrahepatic cholestasis as well as other non-liver injuries, while some other studies indicate that EGR1 protects the liver from CCl₄ exposure by regulating the expression of inducible nitric oxide synthase, cyclooxygenase-2, and tumor necrosis factor-α-regulated genes that have hepatoprotective function.