Induced Liver Inflammation Research Articles

Cholesterol Induces Nrf-2- and HIF-1α-Dependent Hepatocyte Proliferation and Liver Regeneration to Ameliorate Bile Acid Toxicity in Mouse Models of NASH and Fibrosis.

Nonalcoholic steatohepatitis (NASH) is currently one of the most common liver diseases worldwide. The toxic effects of lipids and bile acids contribute to NASH. The regenerative pathway in response to damage to the liver includes activation of the inflammatory process and priming of hepatocytes to proliferate to restore tissue homeostasis. However, the effects of cholesterol on bile acid toxicity, inflammation, and fibrosis remain unknown. We have used two mouse models of bile acid toxicity to induce liver inflammation and fibrosis. A three-week study was conducted using wild-type mice receiving an atherogenic diet (1% (w/w) cholesterol and 0.5% (w/w) cholic acid) and its separate constituents. Mdr2-/- mice were fed a high-cholesterol-enriched diet or standard AIN-93 diet for 6 weeks. We measured serum transaminase levels to assess liver tissue necrosis and fibrosis; iNOS, SAA1, SAA2, and F4/80 levels to determine liver inflammation; PCNA and HGF levels to evaluate proliferative response; and Nrf-2, HIF-1α, and downstream gene expression to establish protective responses. In both studies, high bile acid levels increased serum transaminases and liver fibrosis, whereas cholesterol supplementation attenuated these effects. Cholesterol supplementation activated survival and the robustness of HIF-1α and Nrf-2 gene expression in hepatocytes, induced liver inflammation and hepatocyte proliferation, and inhibited stellate cell hyperplasia and fibrosis. In conclusion, our data show for the first time that cholesterol intake protects against bile acid liver toxicity. The balance between hepatic cholesterol and bile acid levels may be of prognostic value in liver disease progression and trajectory.

Cyclocarya paliurus polysaccharide alleviates liver inflammation in mice via beneficial regulation of gut microbiota and TLR4/MAPK signaling pathways

The study was to investigate the anti-inflammatory effect of Cyclocarya paliurus polysaccharides (CP) on carbon tetrachloride (CCl4) induced mice and explore its underlying mechanism. Based on a mouse model of CCl4 induced liver inflammation and pretreatment with CP. Results showed that CP significantly decreased the levels of the proinflammatory cytokines (NO, TNF-α, IL-1β) as well as the proteins expression levels of COX-2 and iNOS in the liver. TLR4 and MAPK pathways were down-regulated after CP administration. Furthermore, 16S rDNA showed that CP increased the Firmicutes/Bacteroidetes ratio and the abundance of probiotics (Unclassified Clostridiales) as well as decreased abundances of pathogenic bacteria (Proteobacteria, Helicobacter and Aerococcus) compared to model group. Moreover, CP treatment increased the SCFAs levels in CCl4 induced mice. These findings suggested that CP act as prebiotics in ameliorating the liver inflammation in mice caused by CCl4 through regulating the gut microbiota composition and increasing the concentration of SCFAs.

NLRP3 inflammasome drives inflammation in high fructose fed diabetic rat liver: Effect of resveratrol and metformin

AimsTo unravel the underlying mechanism of hepatic inflammation during type 2 diabetes (T2DM), we established the diabetic rat model by feeding with high fructose diet for twenty weeks and studied the involvement of inflammasome in the liver of these rats. Materials and methodsMale SD rats weighing 180–200 g were divided in four groups: 1) Control (Con group) rats were fed with corn starch diet, 2) diabetic (Dia group) rats were fed with 65% of fructose, 3) diabetic along with resveratrol (10 mg/kg/day); p.o. (Dia + Resv group) and 4) diabetic along with metformin (300 mg/kg/day); p.o. (Dia + Met group), for twenty weeks. We evaluated the establishment of T2DM in fructose fed rats and the effect of resveratrol and metformin treatment on different diabetic parameters in these rats. Further we investigated the role of NLRP3 inflammasome on T2DM induced liver inflammation and effect of resveratrol and metformin treatment on NLRP3 inflammasome driven inflammatory response. Key findingsRats from Dia group; manifested insulin resistance, hyperinsulinemia, hyperglycemia, elevated uric acid along with hypertriglyceridemia after fructose feeding for twenty weeks. Mostly, above parameters were attenuated in resveratrol and metformin treated groups. Expression of NLRP3 inflammasome components in liver were increased in Dia group rats with elevated transcript levels of pro-inflammatory cytokines. Histopathological examination revealed increase in glycogen content and fibrosis in Dia group rats; which was considerably reduced with resveratrol and metformin treatment. SignificanceOur study suggests that management of inflammation may be considered as an alternative approach to prevent liver tissue injury during chronic diabetic condition.

First person – Sofia de Oliveira

ABSTRACTFirst Person is a series of interviews with the first authors of a selection of papers published in Disease Models & Mechanisms, helping early-career researchers promote themselves alongside their papers. Sofia de Oliveira is first author on ‘DnaJ-PKAc fusion induces liver inflammation in a zebrafish model of fibrolamellar carcinoma’, published in DMM. Sofia conducted the research described in this article while a postdoctoral fellow in Anna Huttenlocher's lab at the University of Wisconsin-Madison, Madison, WI, USA. She is now an assistant professor at Albert Einstein College of Medicine, Bronx, NY, USA, investigating the impact of Western-type diets on inflammation, and how such effect modulates the progression of different human diseases, particularly liver diseases and infectious diseases.

Epigenetic toxicity of PFOA and GenX in HepG2 cells and their role in lipid metabolism

Perfluorooctanoic acid (PFOA), an extremely persistent perfluoroalkyl substance (PFAS), and 2,3,3,3-Tetrafluoro-2-(heptafluoropropoxy) propanoic acid (GenX), its shorter chain alternative, have been implicated in hepatocellular damage with unusual fat deposit and liver enlargement. In this study we explored the underlying mechanisms of PFOA and GenX induced hepatocellular damage. Liver hepatocellular carcinoma cell line HepG2 was used as a model to study induced liver inflammation in vitro at the cellular, genetic, and epigenetic levels. HepG2 cells were exposed to PFOA or GenX for 48 h and the DNA and RNA were extracted and analyzed. mRNA expression analysis of PFOA exposed cells showed that cell cycle homeostasis genes were affected significantly, as well as the ten-eleven translocation methylcytosine dioxygenases (TETs) and the essential lipid metabolism genes. GenX did not have as significant an effect. Global methylation levels of HepG2 cells were found to be inversely proportional to PFOA exposure levels. With GenX, the global methylation level decreased and then increased. Our work points to the fact that PFOA may contribute to higher overall epigenetic toxicity than GenX, and its induced epigenetic changes may play a major role in lipid metabolism gene regulation and fat deposits.

Ochratoxin A induces liver inflammation: involvement of intestinal microbiota

BackgroundOchratoxin A (OTA) is a widespread mycotoxin and induces liver inflammation to human and various species of animals. The intestinal microbiota has critical importance in liver inflammation; however, it remains to know whether intestinal microbiota mediates the liver inflammation induced by OTA. Here, we treated ducklings with oral gavage of OTA (235 μg/kg body weight) for 2 weeks. Then, the microbiota in the cecum and liver were analyzed with 16S rRNA sequencing, and the inflammation in the liver was analyzed. To explore the role of intestinal microbiota in OTA-induced liver inflammation, intestinal microbiota was cleared with antibiotics and fecal microbiota transplantation was conducted.ResultsHere, we find that OTA treatment in ducks altered the intestinal microbiota composition and structure [e.g., increasing the relative abundance of lipopolysaccharides (LPS)-producing Bacteroides], and induced the accumulation of LPS and inflammation in the liver. Intriguingly, in antibiotic-treated ducks, OTA failed to induce these alterations in the liver. Notably, with the fecal microbiota transplantation (FMT) program, in which ducks were colonized with intestinal microbiota from control or OTA-treated ducks, we elucidated the involvement of intestinal microbiota, especially Bacteroides, in liver inflammation induced by OTA.ConclusionsThese results highlight the role of gut microbiota in OTA-induced liver inflammation and open a new window for novel preventative or therapeutic intervention for mycotoxicosis.

Chronic corticosterone exposure induces liver inflammation and fibrosis in association with m6A-linked post-transcriptional suppression of heat shock proteins in chicken.

Our previous study had shown that chronic corticosterone (CORT) exposure causes excessive fat deposition in chicken liver, yet it remains unknown whether it is associated with inflammation and fibrosis. In general, heat shock proteins (HSPs) are activated in response to acute stress to play a cytoprotective role, and this activation is associated with m6A-mediated post-transcriptional regulation. However, changes of HSPs and the m6A methylation on their mRNAs in response to chronic CORT treatment in chicken liver have not been reported. In this study, chronic CORT exposure induced inflammation and fibrosis in chicken liver, associated with significantly modulated expression of HSPs that was significantly upregulated at mRNA level yet downregulated at protein level. Concurrently, m6A methyltransferases METTL3 content was upregulated together with the level of m6A methylation on HSPs transcripts. The m6A-seq analysis revealed 2-6 significantly (P < 0.05) hypermethylated m6A peaks in the mRNA of 4 different species of HSPs in CORT-treated chicken liver. HSP90B1 transcript had 6 differentially methylated m6A peaks among which peaks on exon 16 and exon 17 showed 3.14- and 4.72-fold of increase, respectively. Mutation of the 8 predicted m6A sites on exon 16 and exon 17 resulted in a significant (P < 0.05) increase in eGFP-fused content of HSP90B1 exon 16 and exon 17 fragment in 293 T cells, indicating a possible role of m6A in post-transcriptional regulation of HSPs. In conclusion, chronic CORT exposure induces inflammation and fibrosis in chicken liver along with an increase in the levels and m6A methylation of several HSPs mRNAs; HSPs levels were however reduced under the indicated conditions. Results presented suggest that the reduction in HSPs levels may be associated with m6A methylation in CORT-exposed chickens.

Ability of prebiotic polysaccharides to activate a HIF1\u03b1-antimicrobial peptide axis determines liver injury risk in zebrafish

Natural polysaccharides have received much attention for their ability to ameliorate hepatic steatosis induced by high-fat diet. However, the potential risks of their use have been less investigated. Here, we show that the exopolysaccharides (EPS) from Lactobacillus rhamnosus GG (LGG) and L. casei BL23 reduce hepatic steatosis in zebrafish fed a high-fat diet, while BL23 EPS, but not LGG EPS, induce liver inflammation and injury. This is due to the fact that BL23 EPS induces gut microbial dysbiosis, while LGG EPS promotes microbial homeostasis. We find that LGG EPS, but not BL23 EPS, can directly activate intestinal HIF1α, and increased HIF1α boosts local antimicrobial peptide expression to facilitate microbial homeostasis, explaining the distinct compositions of LGG EPS- and BL23 EPS-associated microbiota. Finally, we find that liver injury risk is not confined to Lactobacillus-derived EPS but extends to other types of commonly used natural polysaccharides, depending on their HIF1α activation efficiency.

B1 cells protect against Schistosoma japonicum-induced liver inflammation and fibrosis by controlling monocyte infiltration.

During Schistosoma infection, lack of B cells results in more severe granulomas, inflammation, and fibrosis in the liver, but the mechanisms underlying this pathology remain unclear. This study was to clarify the mechanisms underpinning the immunomodulation of B cells in mice infected with Schistosoma japonicum (S. japonicum). We found that B cell deficiency led to aggravated liver pathology, as demonstrated by increases in the size of the egg-associated granulomas, alanine transaminase levels, and collagen deposition. Compared with infected wild-type (WT) mice, infected B cell-deficient (μMT) mice showed increased infiltration of Ly6Chi monocytes and higher levels of proinflammatory cytokines and chemokines. Furthermore, B1 cells were increased significantly in the liver of WT mice following S. japonicum infection. Adoptively transferring B1 cells, but not B2 cells, to μMT mice significantly reduced liver pathology and liver infiltration of Ly6Chi monocytes. Additionally, secretion of IL-10 from hepatic B cells increased significantly in infected WT mice and this IL-10 was mainly derived from B1 cells. Adoptively transferring B1 cells purified from WT mice, but not from IL-10-deficient mice, to μMT mice significantly reduced liver pathology and liver infiltration of Ly6Chi monocytes. These reductions were accompanied by decreases in the expression levels of chemokines and inflammatory cytokines. Taken together, these data indicated that after S. japonicum infection, an increased number of hepatic B1 cells secrete IL-10, which inhibits the expression of chemokines and cytokines and suppresses the infiltration of Ly6Chi monocytes into the liver thereby alleviating liver early inflammation and late fibrosis.

The Hepatic Microenvironment and TRAIL-R2 Impact Outgrowth of Liver Metastases in Pancreatic Cancer after Surgical Resection.

Most patients with pancreatic ductal adenocarcinoma (PDAC) undergoing curative resection relapse within months, often with liver metastases. The hepatic microenvironment determines induction and reversal of dormancy during metastasis. Both tumor growth and metastasis depend on the Tumor necrosis factor (TNF)-related apoptosis-inducing ligand-receptor 2 (TRAIL-R2). This study investigated the interplay of TRAIL-R2 and the hepatic microenvironment in liver metastases formation and the impact of surgical resection. Although TRAIL-R2-knockdown (PancTu-I shTR2) decreased local relapses and number of macroscopic liver metastases after primary tumor resection in an orthotopic PDAC model, the number of micrometastases was increased. Moreover, abdominal surgery induced liver inflammation involving activation of hepatic stellate cells (HSCs) into hepatic myofibroblasts (HMFs). In coculture with HSCs, proliferation of PancTu-I shTR2 cells was significantly lower compared to PancTu-I shCtrl cells, an effect still observed after switching coculture from HSC to HMF, mimicking surgery-mediated liver inflammation and enhancing cell proliferation. CXCL-8/IL-8 blockade diminished HSC-mediated growth inhibition in PancTu-I shTR2 cells, while Vascular Endothelial Growth Factor (VEGF) neutralization decreased HMF-mediated proliferation. Overall, this study points to an important role of TRAIL-R2 in PDAC cells in the interplay with the hepatic microenvironment during metastasis. Resection of primary PDAC seems to induce liver inflammation, which might contribute to outgrowth of liver metastases.

Sphingosine kinase inhibitor regulates pro‐inflammatory cytokines to subdue the neoplastic lesions in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), is the most leading cause of cancer‐related death in all over the world (seems to more than 80% of death cases). It is frequently linked with continuous hepatocytes death, inflammatory cell infiltration, and compensatory liver regeneration with higher angiogenic rate. Considering the different signalling process during this tumorogenesis with the involvement of new ‘lead’ identification of different sources, desire to be less toxic and higher bioavailability. The use of live, attenuated or genetically compensated microbes or its cellular component(s) or metabolites has begun to emerge as a potential new approach in medicinal research to deliver bioactive entities. Thus, advancing our knowledge of such microbes‐mediated therapy may suggest new avenues for therapeutic intervention in many fatal diseases.Sphingosine kinase inhibitor (SKI) II has been reported as a dual inhibitor of sphingosine kinases (SKs) 1 and 2 and has been extensively used to prove the involvement of SKs and sphingosine‐1‐phosphate (S1P) in cellular processes and able to induce apoptosis in human HepG2 (Hepatocellular carcinoma cell, human) cells, as characterized by phosphatidylserine serine exposure, activation of series of caspases and cleaved PARP. SKI also modulates the various transcription factors like NF‐kB‐65, p53 through regulation of cell proliferation exerted the death cause. Moreover, this study also focused that SKI effectively suppressed diethylnitrosamine (DEN) induced liver inflammation and hyperplasia in murine, also regulated the lipid peroxidation and enzymic antioxidants (SOD, CAT, GPx, GR and GST) status with an improvement of their survival rate. It reduced the elevated level of cytokines including tumor necrosis factors, interleukins, interferon (alpha and gamma), and transforming growth factors in hepatocytes from liver fibrosis bearing mice. As evident from an immunochemical analysis, DEN‐induced neoplastic lesions may up‐regulate the various growth factors including EGF, HGF, endothelin‐1 regulation with promoting angiogenic activity via modulation of CD34, VEGF, HIF‐1α expression and we found that the alteration of these changes were balanced by SKI treatment in vivo system. So taken together, these finding indicated that, SKI may recover in hyperproliferating cancer cells with tumor growth regulation in carcinogen‐exposed rodent system. In future direction, we will check the p53−/− and cmyc−/− mice that hoe it could regulate cancer metastasis with this SKI. and the involvement of od tumor microenvironment.Support or Funding InformationCSIR and Department of Science and Technology, IndiaThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Natural Killer Cell-Derived Interferon-Gamma Promotes Hepatocellular Carcinoma Through the Epithelial Cell Adhesion Molecule-Epithelial-to-Mesenchymal Transition Axis in Hepatitis B Virus Transgenic Mice.

Hepatitis B virus (HBV) is a major risk factor for development of hepatocellular carcinoma (HCC), at least partially due to dysfunctional anti-HBV adaptive immunity; however, the role of innate immune response to HBV in this process is not well understood. In this study, low-dose polyinosinic:polycytidylic acid (poly [I:C]), a natural killer (NK) cell activator (3 μg/g body weight, twice/week for 8 weeks), induced HCC in HBV transgenic (HBs-Tg) mice, with an incidence of 100% after 6 months, while HBs-Tg mice without treatment only had HCC with an incidence of 16.7%. In HBs-Tg mice, poly (I:C) induced liver inflammation with markedly increased infiltrating lymphocytes, along with the concurrently increased apoptosis and proliferation of hepatocytes, leading to the accelerated epithelial-to-mesenchymal transition (EMT) of hepatocytes shown by increased expression of the typical transcriptional factors (Slug, Twist, and mothers against decapentaplegic-interacting protein 1) and phenotypic proteins (vimentin and chemokine [C-X-C motif] receptor 4). The EMT and tumorigenesis in this model depended on the presence of NK cells because depletion of these cells significantly reduced the HCC rate to 28.6%. Further, intrahepatic NK cells highly expressed interferon-gamma (IFN-γ), anti-IFN-γ neutralizing monoclonal antibody might obviously alleviate the hepatitis, and hepatocyte-specific IFN-γ overexpression promoted HCC. Moreover, IFN-γ deficiency in HBs-Tg mice prevented HCC occurring, though hepatic NK cells existed and could be activated, suggesting the critical role of IFN-γ in NK cell-mediated tumorigenesis. In an in vitro experiment, IFN-γ up-regulated epithelial cell adhesion molecule (EpCAM) expression through phosphorylated signal transducer and activator of transcription (p-STAT1) pathway, which was followed by EMT, and p-STAT1 inhibitor might absolutely abolish the expression of EpCAM and EMT in HBV surface antigen-positive hepatocytes. Conclusion: This work demonstrates that NK cell-derived IFN-γ promotes HCC through the EpCAM-EMT axis in HBs-Tg mice, revealing the importance of innate immunity in pathogenesis of HBV-associated HCC.

Targeting NLRP3 inflammasome via acetylsalicylic acid: Role in suppressing hepatic dysfunction and insulin resistance induced by atorvastatin in naïve versus alcoholic liver in rats

BackgroundNLRP3 inflammasome is described in many pathological conditions and is also involved in drug induced liver injury. Aim of the workTo investigate the role of NLRP3 inflammasome in liver injury induced by chronic alcohol and/or atorvastatin ingestion. Materials and methodsSixty male Wistar rats were used. They were divided into 5 groups: (I) control naïve (II) Alcoholic: given ethanol 8 g/kg/day, p.o (III) Atorvastatin: given atorvastatin 10 mg/kg/day, p.o. (IV) Alcoholic + atorvastatin (V) Acetylsalicylic acid (ASA): given ASA 10 mg/kg/day, p.o together with alcohol and atorvastatin. Isolated perfused liver, biochemical and histological studies were done. ResultsAtorvastatin and alcohol induced liver inflammation with increasing the expression of NLRP3, IL-1β and caspase-8 immune-reaction. Atorvastatin and alcohol decreased the reduced form of glutathione in hepatic tissues and induced insulin resistance. ASA administration alleviated the hepatotoxic effects of alcohol and atorvastatin to a significant extent. ConclusionsAcetylsalicylic acid alleviated the hepatotoxic effects of alcohol and atorvastatin through decreasing the production of NLRP3 inflammasome in rats' liver.

Sodium Butyrate Mitigates iE-DAP Induced Inflammation Caused by High-Concentrate Feeding in Liver of Dairy Goats.

The aim of this study is to explore the impact of sodium butyrate on d-glutamyl- meso-diaminopimelic acid (iE-DAP)-induced liver inflammation in dairy goats during subacute ruminal acidosis (SARA) caused by high-concentrate feed. To achieve this aim, 12 lactating dairy goats were randomly divided into two groups: a high-concentrate feed group ( n = 6, concentrate/forage = 6:4) as the control group and a sodium butyrate (SB) with high-concentrate feed group ( n = 6, concentrate/forage = 6:4, with 1% SB by wt.) as the treatment group. A rumen pH below 5.6 lasted for at least 4 h/d due to long-term HC feeding. The concentration of iE-DAP was significantly lower (11.67 ± 3.85 μg/mL, and 7.74 ± 1.46 μg/mL, at the fourth h and sixth h of feeding, respectively) in the SB-treated group than that in the HC group (51.45 ± 5.71 μg/mL, and 18.31 ± 3.83 μg/mL, at the fourth h and sixth h of feeding, respectively). Meanwhile, SB significantly suppressed the mRNA expression of inflammatory genes (NOD1, RIPK2, TAK1, NF-κB/p65, ERK, JNK2, p38, IL-1β, TNF-α, CCL5, CCL20, CXCL12, FOS, β-defensin/LAP). Moreover, the protein expression of NOD1, p-IκBα, p-NF-κB/p-p65, p-ERK1/2, p-JNK, p-p38, and HDAC3 was significantly downregulated in the HC+SB group. In conclusion, iE-DAP-induced inflammation and liver disruption generated by the HC diet was mitigated by SB treatment.

Abstract 3942: The fraction of garlic protein(s) affect HCC via regulation of angiogenesis

Abstract Cancers are leading cause of human mortality. Most of deaths are due cancer because of its high resistance to the chemotherapeutic drugs. Thus, there is an ongoing demand for generation of new potent and more effective therapies for cancer treatment. Hepatocellular carcinoma (HCC), is the most leading cause of cancer-related death in all over the world (seems to more than 80% of death cases in USA). It is frequently linked with continuous hepatocytes death, inflammatory cell infiltration, and compensatory liver regeneration with higher angiogenic rate. Considering the different signaling process during this tumorigenesis with the involvement of new ‘lead' identification of various sources, desire to be less toxic and higher bioavailability. The use of natural or its active metabolic component(s) has begun to emerge as a potential innovative approach in medicinal research to deliver bioactive entities. Thus, garlic has already proven as the therapeutic implication on immune system and cancer due to presence of sulfur compound. But the role of active protein fraction present in fresh garlic is still not revealed yet. In our study, we are isolated an active garlic protein from fresh garlic aqueous extract with molecular weight about 40-45kD. This Garlic protein (GP) having non-cytotoxic to human/murine normal cells, could induce apoptosis in human HepG2 cells, as characterized by phosphatydylserine serine exposure, DNA fragmentation, alteration with loss of mitochondrial membrane potential and cytochrome C release, activation of series of caspases, other physiochemical changes lead to induce cancer cell death. This study also focused that the GP effectively suppressed DEN induced liver inflammation and hyperplasia in murine also decline in lipid peroxidation and changes in enzymic antioxidants and biochemical parameter with improvement of their survival rate. It reduced the elevated level of cytokines and growth factors in hepatocytes from liver fibrosis bearing mice. Thus, finding indicated that, GP may induce apoptosis and in hyper proliferating cancer cells via altering cytokines-chemokines level with tumor growth regulation in carcinogen exposed rodent system. Future direction, we are proposing to execute the experiments on p53-/- and cMyc-/- deficient mice to find out the role of GP in these circumstances. Citation Format: Nabanita Chatterjee, Subhadip Das, Prajnamoy Pal, Krishna Das Saha. The fraction of garlic protein(s) affect HCC via regulation of angiogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3942.

Short-term treatment with metformin reduces hepatic lipid accumulation but induces liver inflammation in obese mice.

The study aimed to evaluate the metabolic and inflammatory effects of short-term treatments (10days) with metformin (MET) on the NAFLD caused by a high-fat diet (HFD) in C57BL/6 mice. After the treatment, histological liver slices were obtained, hepatocytes and macrophages were extracted and cultured with phosphate buffered saline, LPS (2.5µg/mL) and MET (1µM) for 24h. Cytokine levels were determined by ELISA. NAFLD caused by the HFD was partially reduced by MET. The lipid accumulation induced by the HFD was not associated with liver inflammation; however, MET seemed to promote pro-inflammatory effects in liver, since it increased hepatic concentration of IL-1β, TNF-α, IL-6, MCP-1 and IFN-γ. Similarly, MET increased the concentration of IL-1β, IL-6 in hepatocyte cultures. However, in macrophages culture, MET lowered levels of IL-1β, IL-6 and TNF-α stimulated by LPS. Overall, MET reduced liver NAFLD but promoted hepatocyte increase in pro-inflammatory cytokines, thus, leading to liver inflammation.

Effect of autophagy inhibitor chloroquine on acute alcoholinduced liver disease

To investigate the role of autophagy inhibitor chloroquine (CQ) in acute ethanol-induced liver injury and its mechenism. Twenty-one C57BL/6 male mice were randomly divided into three groups:control group, ethanol group, CQ + ethanol group (n=7). Mice in ethanol group were administered 33% (v/v) ethanol at a dose of 4.5 g/kg body weight. Ethanol-induced liver steatosis in each group was detected by hematoxylin and eosin staining. Hepatic lipid accumulation was detected by staining with Oil red O. Hepatic tissue triglyceride (TG) levels, serum aspartate aminotransferase(AST) and alanine aminotransferase(ALT) were determined by biochemical assays. Protein expression of microtubule-associated protein 1 light chain 3(LC3) and nuclear factorκB p65(NF-κB p65) were measured by Western blot and immunofluorescence. Pro-inflammatory factors tumor necrosis factor-α(TNF-α)、interleukin 6(IL-6) were detected by ELISA. Compared with control group, ethanol induced liver injury proved by accumulation of hepatic lipids, TG levels, AST and ALT activities were significantly increased by ethanol, protein expression of LC3-Ⅱ was also markedly increased by ethanol. Compared with ethanol group, addition of CQ increased furtherthe level of LC3-Ⅱexpression, and TG amount, serum AST and ALT activities, and the expression of NF-κB p65, TNF-αand IL-6. Acute ethanol-intake could induce liver steatosis and inflammation, and autophagy inhibitor CQ exacerbatedethanol-induced liver injury, suggested that autophagy might be protective effect in acute ethanol-induced liver disease.

Silybin inhibits NLRP3 inflammasome assembly through the NAD+/SIRT2 pathway in mice with nonalcoholic fatty liver disease.

Silybin is one of the effective, traditional Chinese medicines used as a hepatoprotective agent in nonalcoholic fatty liver disease (NAFLD) therapy worldwide, and the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome has been recognized as an important factor involved in NAFLD development. However, little is known about the mechanisms of silybin in the regulation of high-fat diet (HFD)-induced liver inflammation. In our study, we found that silybin inhibited endoplasmic reticulum stress and NLRP3 inflammasome activation in the livers of HFD-fed mice and in cultured hepatocytes. Phosphorylation of inositol-requiring enzyme (IRE)1α and eIF2α, expression of thioredoxin-interacting protein and cleaved caspase-1, and release of IL-1β were reduced by silybin. In addition, silybin inhibited the approach of calreticulin and translocase of outer membrane 20 (Tom20), prevented assembly of the NLRP3 inflammasome complex, and suppressed the accumulation of acetylated α-tubulin in the perinuclear region. Both MEC-17 and sirtuin 2 (SIRT2) were influenced by palmitate and silybin, whereas histone deacetylase 6 was not affected. In addition, supplementing NAD+ directly or increasing NAD+ concentration with silybin could maintain the activity of SIRT2. The anti-inflammatory effect of silybin was blocked by SIRT2 silencing or by the SIRT2 inhibitor AGK2, as evidenced by NLRP3/ASC colocalization, AC-α-tubulin expression, and IL-1β release. These findings indicate that the NAD+/SIRT2 pathway is an important mediator through which silybin prevents NLRP3 inflammasome activation during NAFLD.-Zhang, B., Xu, D., She, L., Wang, Z., Yang, N., Sun, R., Zhang, Y., Yan, C., Wei, Q., Aa, J., Liu, B., Wang, G., Xie, Y. Silybin inhibits NLRP3 inflammasome assembly through the NAD+/SIRT2 pathway in mice with nonalcoholic fatty liver disease.

Interactions Between Platelets and Inflammatory Monocytes Affect Sickness Behavior in Mice With Liver Inflammation

Patients with inflammatory liver disease commonly develop debilitating symptoms, called sickness behaviors, which arise via changes in brain function. Monocytes that produce tumor necrosis factor interact with cerebral endothelial cells to activate microglial cells and promote sickness behavior. Platelets regulate inflammation, and aggregates of monocytes and platelets are increased in the circulation of patients with liver disease. We investigated the role of platelets in inducing inflammatory features of circulating monocytes and promoting sickness behaviors in mice with cholestatic liver injury. We performed bile-duct ligations or sham surgeries on C57BL/6 or toll-like receptor 4 (TLR4)-knockout mice to induce liver inflammation. Liver inflammation was also induced in a separate group of mice by administration of concanavalin A. Circulating platelets, aggregates of monocytes and platelets, and activation of microglial cells were measured by flow cytometry. To deplete platelets, mice were given anti-thrombocyte serum or normal rabbit serum (control) 4 days after surgery. Interactions between monocytes and cerebral endothelial cells were analyzed by intravital microscopy. Sickness behaviors were quantified based on time spent by adult mice engaging in social behaviors toward a juvenile mouse, compared with time spent in nonsocial behavior or remaining immobile. Aggregates of monocytes and platelets in circulation of mice increased significantly following bile-duct ligation. Platelet-monocyte interactions were required for activation of inflammatory monocytes and production of tumor necrosis factor. Platelet depletion greatly reduced adhesive interactions between inflammatory monocytes and adhesive interactions with cerebral endothelial cells and activation of the microglia, as well as development of sickness behavior. Furthermore, TLR4 signaling was important for aggregation ofmonocytes and platelets, and development of sickness behavior following bile-duct ligation. These findings were confirmed in mice with concanavalin A-induced liver injury. In mice with liver inflammation, we found TLR4 and aggregates of monocytes and platelets to regulate microglial activation and development of sickness behavior. These findings might lead to new therapeutic strategies for liver disease-associated symptoms.

Gut Microbiome Response to Sucralose and Its Potential Role in Inducing Liver Inflammation in Mice.

Sucralose is the most widely used artificial sweetener, and its health effects have been highly debated over the years. In particular, previous studies have shown that sucralose consumption can alter the gut microbiota. The gut microbiome plays a key role in processes related to host health, such as food digestion and fermentation, immune cell development, and enteric nervous system regulation. Inflammation is one of the most common effects associated with gut microbiome dysbiosis, which has been linked to a series of human diseases, such as diabetes and obesity. The aim of this study was to investigate the structural and functional effects of sucralose on the gut microbiota and associated inflammation in the host. In this study, C57BL/6 male mice received sucralose in their drinking water for 6 months. The difference in gut microbiota composition and metabolites between control and sucralose-treated mice was determined using 16S rRNA gene sequencing, functional gene enrichment analysis and metabolomics. Inflammatory gene expression in tissues was analyzed by RT-PCR. Alterations in bacterial genera showed that sucralose affects the gut microbiota and its developmental dynamics. Enrichment of bacterial pro-inflammatory genes and disruption in fecal metabolites suggest that 6-month sucralose consumption at the human acceptable daily intake (ADI) may increase the risk of developing tissue inflammation by disrupting the gut microbiota, which is supported by elevated pro-inflammatory gene expression in the liver of sucralose-treated mice. Our results highlight the role of sucralose-gut microbiome interaction in regulating host health-related processes, particularly chronic inflammation.