Chronic Liver Inflammation Research Articles

Nocardia seriolae mediates liver granulomatous chronic inflammation in Micropterus salmoides through pyroptosis.

Granulomatous diseases caused by Nocardia seriously endanger the health of cultured fish. These bacteria are widely distributed, but prevention and treatment methods are very limited. Chronic granulomatous inflammation is an important pathological feature of Nocardia infection. However, the molecular mechanisms of granuloma formation and chronic inflammation are still unclear. Constructing a granuloma infection model of Nocardia is the key to exploring the pathogenesis of the disease. In this study, we established a granuloma model in the liver of largemouth bass (Micropterus salmoides) and assessed the infection process of Nocardia seriolae at different concentrations by analysing relevant pathological features. By measuring the expression of pro-inflammatory cytokines, transcription factors and a pyroptosis-related protein, we revealed the close relationship between pyroptosis and chronic inflammation of granulomas. We further analysed the immunofluorescence results and the expression of pyroptosis-related protein of macrophage infected by N. seriolae and found that N. seriolae infection induced macrophage pyroptosis in vitro. These results were proved by flow cytometry analysis of infection experiment in vivo. Our results indicated that the pyroptosis effect may be the key to inducing chronic inflammation in the fish liver and further mediating granuloma formation. In this study, we explored the molecular mechanism underlying chronic inflammation of granulomas and developed research ideas for understanding the occurrence and development of granulomatous diseases in fish.

Hepatic fibrosis: Targeting peroxisome proliferator-activated receptor alpha from mechanism to medicines.

Liver fibrosis is the result of sustained chronic liver injury and inflammation leading to hepatocyte cell death followed by the formation of fibrous scars, which is the hallmark of NASH and alcoholic steatohepatitis and can lead to cirrhosis, HCC, and liver failure. Although progress has been made in understanding the pathogenesis and clinical consequences of hepatic fibrosis, therapeutic strategies for this disease are limited. Preclinical studies suggest that peroxisome proliferator-activated receptor alpha plays an important role in preventing the development of liver fibrosis by activating genes involved in detoxifying lipotoxicity and toxins, transrepressing genes involved in inflammation, and inhibiting activation of hepatic stellate cells. Given the robust preclinical data, several peroxisome proliferator-activated receptor alpha agonists have been tested in clinical trials for liver fibrosis. Here, we provide an update on recent progress in understanding the mechanisms by which peroxisome proliferator-activated receptor alpha prevents fibrosis and discuss the potential of targeting PPARα for the development of antifibrotic treatments.

Impact of eradication of hepatitis C virus on liver-related and -unrelated diseases: morbidity and mortality of chronic hepatitis C after SVR.

Hepatitis C virus infection is characterized by chronic liver inflammation and fibrogenesis, leading to end-stage liver failure and hepatocellular carcinoma over the course of 20 to 30years. It seems not only the chronicity of hepatitis C but also the presence of the virus in non-hepatic tissues creates a favorable environment for the potential development of pathogenic impacts on extrahepatic systems and organs. Numerous extra-hepatic manifestations have been reported in association with HCV infection, all of which can substantially affect morbidity, mortality, and quality of life. With the recent development of DAAs, antiviral treatment can cure almost all patients with HCV infection, even those intolerant of or unresponsive to IFN treatment, and several large multicenter studies have confirmed the association of DAA-induced SVR with reductions in liver-related and liver-unrelated complications, such as cardiovascular events, end stage renal disease, and so on. Because, in addition to liver-related diseases, extrahepatic lesions are threatening for patients, it is important to eradicate the virus before these progress and affect life prognosis; in other words, patients should be treated before reaching the point of no return. Tailored surveillance with biomarkers such as M2BPGi and Ang-2, which can be used to identify patients with an elevated risk of EHM, and early prevention or treatment for these patients could improve the morbidity, mortality and QOL. Advancement of both basic and clinical research in this field including the development of more precise biomarkers is highly anticipated.

HBsAg Pozitif Hastaların Trombosit İndekslerinin Değerlendirilmesi /Evaluation of Platelet Indexes of HBsAg Positive Patients

OBJECTIVE: Hepatitis B virus is the most important cause of chronic liver inflammation. Studies showing that platelets have important functions as an inflammatory trigger in cases of chronic inflammation have increased in recent years. Expressed as platelet (PLT) indices; platelet volume (MPV), platelet distribution width (PDW), and platelet percentage (PCT) values; it is one of the important markers that provide information about the function and activation of platelets. In this study, in HBsAg positive and HBsAg negative patients, it is aimed to evaluate the parameters of PLT, MPV, PDW and PCT. MATERIALS AND METHODS: In this retrospective study, the results of 193 HBsAg positive and 193 HBsAg negative patients who applied to Infectious Diseases Outpatient Clinic of Uşak University Faculty of Medicine Training and Research Hospital were evaluated. The values of PLT, PDW, PCT and MPV parameters were determined using a hemogram device. Student t-test and one- way ANOVA test were used for comparison between the groups. A value of P<0.05 was considered as statistically significant. RESULTS: In our study, while PLT, PDW, PCT and MPV values were determined as 227.36±69.98 103/mm3, 16.34±1.52%, 0.22±0.62% and 9.74±1.10 fl, respectively, in the HBsAg positive patient group, the same values were determined as 224.95±67.48 103/mm3, 16.16±1.08%, 0.22±0.62%, 9.82±1.20 fl, respectively, (p>0.05, p>0.05, p>0.05 and p>0.05, respectively) in the HBsAg negative patient group. In terms of these values, no statistically significant difference was found between the HBsAg positive patient group and the HBsAg negative patient group. In the correlation analysis performed in all cases (n=386), it can be said that there is a very strong negative correlation between PLT and age, MPV, and PDW (respectively, r=-0.156 p=0.06, r=-0.394 p<0.01, r=-0.467 p< 0.01). It was also determined that there was a strong positive correlation (r=0.915 p<0.01) between PLT and PCT. CONCLUSION: In this study, there was no significant difference between HBsAg positive patients and HBsAg negative patients in terms of platelet indices. We recommend that studies on this subject be conducted by grouping hepatitis B patients according to different clinical stages.

SARS-CoV-2-mediated liver injury: pathophysiology and mechanisms of disease.

SARS-CoV-2-induced severe inflammatory response can be associated with severe medical consequences leading to multi-organ failure, including the liver. The main mechanism behind this assault is the aggressive cytokine storm that induces cytotoxicity in various organs. Of interest, hepatic stellate cells (HSC) respond acutely to liver injury through several molecular mechanisms, hence furthering the perpetuation of the cytokine storm and its resultant tissue damage. In addition, hepatocytes undergo apoptosis or necrosis resulting in the release of pro-inflammatory and pro-fibrogenic mediators that lead to chronic liver inflammation. The aim of this review is to summarize available data on SARS-CoV-2-induced liver inflammation in addition to evaluate the potential effect of anti-inflammatory drugs in attenuating SARS-CoV-2-induced liver inflammation. Thorough PubMed search was done to gather and summarize published data on SARS-CoV-2-induced liver inflammation. Additionally, various anti-inflammatory potential treatments were also documented. Published data documented SARS-CoV-2 infection of liver tissues and is prominent in most liver cells. Also, histological analysis showed various features of tissues damage, e.g., hepatocellular necrosis, mitosis, cellular infiltration, and fatty degeneration in addition to microvesicular steatosis and inflammation. Finally, the efficacy of the different drugs used to treat SARS-CoV-2-induced liver injury, in particular the anti-inflammatory remedies, are likely to have some beneficial effect to treat liver injury in COVID-19. SARS-CoV-2-induced liver inflammation is a serious condition, and drugs with potent anti-inflammatory effect can play a major role in preventing irreversible liver damage in COVID-19.

Prolonged hypernutrition impairs TREM2-dependent efferocytosis to license chronic liver inflammation and NASH development

Obesity-induced chronic liver inflammation is a hallmark of nonalcoholic steatohepatitis (NASH)-an aggressive form of nonalcoholic fatty liver disease. However, it remains unclear how such a low-grade, yet persistent, inflammation is sustained in the liver. Here, we show that the macrophage phagocytic receptor TREM2, induced by hepatocyte-derived sphingosine-1-phosphate, was required for efferocytosis of lipid-laden apoptotic hepatocytes and thereby maintained liver immune homeostasis. However, prolonged hypernutrition led to the production of proinflammatory cytokines TNF and IL-1β in the liver to induce TREM2 shedding through ADAM17-dependent proteolytic cleavage. Loss of TREM2 resulted in aberrant accumulation of dying hepatocytes, thereby further augmenting proinflammatory cytokine production. This ultimately precipitated a vicious cycle that licensed chronic inflammation to drive simple steatosis transition to NASH. Therefore, impaired macrophage efferocytosis is a previously unrecognized key pathogenic event that enables chronic liver inflammation in obesity. Blocking TREM2 cleavage to restore efferocytosis may represent an effective strategy to treat NASH.

Methylation-sensitive high-resolution melting analysis of the USP44 promoter can detect early-stage hepatocellular carcinoma in blood samples

Hepatocellular carcinoma (HCC) is dangerous cancer that often evades early detection because it is asymptomatic and an effective detection method is lacking. For people with chronic liver inflammation who are at high risk of developing HCC, a sensitive detection method for HCC is needed. In a meta-analysis of The Cancer Genome Atlas pan-cancer methylation database, we identified a CpG island in the USP44 promoter that is methylated specifically in HCC. We developed methylation-sensitive high-resolution melting (MS-HRM) analysis to measure the methylation levels of the USP promoter in cell-free DNA isolated from patients. Our MS-HRM assay correctly identified 40% of patients with early-stage HCC, whereas the α-fetoprotein test, which is currently used to detect HCC, correctly identified only 25% of early-stage HCC patients. These results demonstrate that USP44 MS-HRM analysis is suitable for HCC surveillance. [BMB Reports 2022; 55(11): 553-558].

Innate Immunity, Inflammation, and Intervention in HBV Infection.

Hepatitis B virus (HBV) infection is still one of the most dangerous viral illnesses. HBV infects around 257 million individuals worldwide. Hepatitis B in many individuals ultimately develops hepatocellular carcinoma (HCC), which is the sixth most common cancer and the third leading cause of cancer-related deaths worldwide. The innate immunity acts as the first line of defense against HBV infection through activating antiviral genes. Along with the immune responses, pro-inflammatory cytokines are triggered to enhance the antiviral responses, but this may result in acute or chronic liver inflammation, especially when the clearance of virus is unsuccessful. To a degree, the host innate immune and inflammatory responses dominate the HBV infection and liver pathogenesis. Thus, it is crucial to figure out the signaling pathways involved in the activation of antiviral factors and inflammatory cytokines. Here, we review the interplay between HBV and the signal pathways that mediates innate immune responses and inflammation. In addition, we summarize current therapeutic strategies for HBV infection via modulating innate immunity or inflammation. Characterizing the mechanisms that underlie these HBV-host interplays might provide new approaches for the cure of chronic HBV infection.

Evogliptin Directly Inhibits Inflammatory and Fibrotic Signaling in Isolated Liver Cells.

Chronic liver inflammation can lead to fibrosis, cirrhosis, and hepatocellular carcinoma. Kupffer cells (KC) secrete proinflammatory and fibrogenic cytokines in response to lipopolysaccharide (LPS), and so play an important role in liver inflammation, where they induce hepatocellular damage. LPS also activates hepatic stellate cells and induces extracellular matrix deposition. In this study, we used isolated primary KC, primary hepatocytes, and primary hepatic stellate cells (HSC) to investigate whether evogliptin directly inhibits inflammatory and fibrotic signaling. We found that evogliptin inhibited LPS-induced secretion of inducible nitric oxide synthase and transforming growth factor β (TGF-β) from KC. Moreover, evogliptin inhibited inflammatory mediator release from hepatocytes and hepatic stellate cell activation that were induced by KC-secreted cytokines. In hepatocytes, evogliptin also inhibited LPS-induced expression of proinflammatory cytokines and fibrotic TGF-β. In addition, evogliptin inhibited TGF-β-induced increases in connective tissue growth factor levels and HSC activation. These findings indicate that evogliptin inhibits inflammatory and fibrotic signaling in liver cells. We also showed that the inhibitory effect of evogliptin on inflammatory and fibrotic signaling is associated with the induction of autophagy.

Effects of bifid triple viable on chronic low-grade inflammation in obese mice induced by high fat diet

To explore the effects and possible mechanism of bifid triple viable(BTV) on chronic low-grade inflammation and insulin resistance in obese mice induced by high fat diet(DIO). A total of 18 male C57 BL/6 J mice aged 6 weeks were randomly divided into two groups according to their body weight after adaptive feeding for 2 weeks. Six mice in one group were fed with normal rodent diet as control group. Twelve mice in the other group were fed with high fat diet(60% kcal% fat)(HF). After 8 weeks, it was confirmed that body weight and fasting blood glucose of the mice fed with high fat diet were significantly higher than those of the control group(P<0.001), and then they were randomly divided into HF group and HF+BTV group according to the body weight and fasting blood glucose. Six mice in the HF group continued to be fed with high fat diet. Six mice in the HF+BTV group were fed with high fat diet and administered bifid triple viable suspension by gavage(24 mg/kg body weight), once a day. Mice in the control group and HF group were given equal volume of water as control treatment. After 4 weeks of treatment, blood was collected from tail vein, and the fasting blood glucose was measured by automatic glucose meter. Then the animals were killed and collected blood, distal ileum, liver and epididymal white adipose tissue. The tight junctions between the epithelial cells of ileum mucosa were observed by transmission electron microscopy. Serum endotoxin(also called lipopolysaccharide, LPS) levels were determined by limulus amebocyte lysate assay. Immunohistochemical staining was used to observe the macrophage marker F4/80 in liver and epididymal white adipose tissue. Serum fasting insulin levels, tumor necrosis factor-α(TNF-α), interlukin-6(IL-6) and monocyte chemotactic protein-1(MCP-1) in liver and/or epididymal white adipose tissue were detected by ELISA. The index of homeostasis model assessment of insulin resistance(HOMA-IR) was calculated by formula. Compared with the mice fed with normal rodents diet, the tight junctions between the epithelial cells of ileum mucosa were loose, the levels of serum endotoxin, live TNF-α and IL-6, epididymal white adipose tissue TNF-α, IL-6, MCP-1 were significantly elevated(P<0.05), the number of macrophages increased in liver and epididymal white adipose tissue, fasting glucose, fasting insulin levels and HOMA-IR were significantly up-regulated(P<0.01) in the HF group. In comparison with the HF group, the structures of tight junctions between the epithelial cells of ileum mucosa were normalized, the levels of serum endotoxin, liver TNF-α, IL-6 and epididymal white adipose tissue TNF-α, IL-6, MCP-1 were obviously decreased(P<0.05), the number of macrophages reduced in liver and epididymal white adipocytes, fasting insulin levels and HOMA-IR were significantly down-regulated(P<0.05), but had no effect on fasting blood glucose levels in HF+BTV group. Bifid triple viable may protect intestinal mucosa barrier, alleviate metabolic endotoxemia, thus improve chronic low-grade inflammation in liver and adipose tissue, and partially restore insulin sensitivity in DIO mice by regulating gut microbiota.

Optimized Cationic Lipid-assisted Nanoparticle for Delivering CpG Oligodeoxynucleotides to Treat Hepatitis B Virus Infection.

Hepatitis B virus (HBV) infection is such a global health problem that hundreds of millions of people are HBV carriers. Current anti-viral agents can inhibit HBV replication, but can hardly eradicate HBV. Cytosine-phosphate-guanosine (CpG) oligodeoxynucleotides (ODNs) are an adjuvant that can activate plasmacytoid dendritic cells (pDCs) and conventional dendritic cells (cDCs) to induce therapeutic immunity for HBV eradication. However, efficient delivery of CpG ODNs into pDCs and cDCs remains a challenge. In this study, we constructed a series of cationic lipid-assisted nanoparticles (CLANs) using different cationic lipids to screen an optimal nanoparticle for delivering CpG ODNs into pDCs and cDCs. We constructed different CLANCpG using six cationic lipids and analyzed the cellular uptake of different CLANCpG by pDCs and cDCs in vitro and in vivo, and further analyzed the efficiency of different CLANCpG for activating pDCs and cDCs in both wild type mice and HBV-carrier mice. We found that CLAN fabricated with 1,2-Dioleoyl-3-trimethylammonium propane (DOTAP) showed the highest efficiency for delivering CpG ODNs into pDCs and cDCs, resulting in strong therapeutic immunity in HBV-carrier mice. By using CLANCpG as an immune adjuvant in combination with the injection of recombinant hepatitis B surface antigen (rHBsAg), HBV was successfully eradicated and the chronic liver inflammation in HBV-carrier mice was reduced. We screened an optimized CLAN fabricated with DOTAP for efficient delivery of CpG ODNs to pDCs and cDCs, which can act as a therapeutic vaccine adjuvant for treating HBV infection.

Effect of Chlorogenic Acid via Upregulating Resolvin D1 Inhibiting the NF-κB Pathway on Chronic Restraint Stress-Induced Liver Inflammation.

Chronic stress can cause chronic inflammatory injury to the liver. Chlorogenic acid (CGA) is known to have a wide range of biological activities and anti-inflammatory effects. Resolvin D1 (RvD1) is a polyunsaturated fatty acid derivative that has inhibitory effects on a variety of inflammatory diseases. However, whether CGA can inhibit liver inflammation in chronic stress through RvD1 remains unclear. In this work, male rats were subjected to restraint stress for 6 h every day and built a chronic stress model for 21 days. CGA (100 mg/kg) was administered intragastrically 1 h before restraint, with intraperitoneal injection of RvD1 inhibitor WRW4 (antagonist of FPR2, 0.1 mg/kg) or WRW4 solution every 2 days for 30 min before CGA administration. CGA reduced hepatic hemorrhage and inflammatory cell infiltration, alleviated hepatic injury, decreased the activation of the NF-κB pathway and the expression of interleukin 1β, interleukin 6, and tumor necrosis factor α in the liver, and increased RvD1 in the serum and liver. The therapeutic effect of CGA was blocked after WRW4 intervention. These results suggest that the protective effects of CGA mediate the NF-κB pathway by upregulating the generation of RvD1. Above all, this research demonstrates the liver protective effect of CGA and provides a potential treatment strategy for chronic inflammatory disease.

Nanostructured Lipid Carriers Loaded with Dexamethasone Prevent Inflammatory Responses in Primary Non-Parenchymal Liver Cells.

Liver inflammation represents a major clinical problem in a wide range of pathologies. Among the strategies to prevent liver failure, dexamethasone (DXM) has been widely used to suppress inflammatory responses. The use of nanocarriers for encapsulation and sustained release of glucocorticoids to liver cells could provide a solution to prevent severe side effects associated with systemic delivery as the conventional treatment regime. Here we describe a nanostructured lipid carrier developed to efficiently encapsulate and release DXM. This nano-formulation proved to be stable over time, did not interact in vitro with plasma opsonins, and was well tolerated by primary non-parenchymal liver cells (NPCs). Released DXM preserved its pharmacological activity, as evidenced by inducing robust anti-inflammatory responses in NPCs. Taken together, nanostructured lipid carriers may constitute a reliable platform for the delivery of DXM to treat pathologies associated with chronic liver inflammation.

Exendin-4 Attenuates Hepatic Steatosis by Promoting the Autophagy-Lysosomal Pathway.

Dysregulated hepatic steatosis may lead to chronic liver inflammation and nonalcoholic steatohepatitis (NASH). Recent studies have suggested that exendin-4, a glucagon-like peptide-1 agonist, may be a promising therapeutic for hepatic steatosis and NASH. However, the molecular mechanisms underlying the antihepatic steatosis actions of exendin-4 are not fully clear. Here, we demonstrate that autophagy is activated by either palmitic acid (PA) or oleic acid (OA) in HepG2 cells, and exendin-4 further enhances the autophagy-lysosomal pathway. We show that inhibition of autophagy by shLC3 attenuates exendin-4-mediated antisteatotic activity. Furthermore, expression of a key lysosomal marker, lysosome associated membrane protein 1 (LAMP1), is upregulated in OA + exendin-4-treated cells. The colocalization of LAMP1 and LC3 puncta further suggests that autophagic flux was enhanced by the cotreatment. Based on these findings, we conclude that autophagic flux might play an important role in the antisteatotic action of exendin-4.

T cells and liver fibrosis

AbstractLiver fibrosis develops from the excessive deposition of extracellular matrix in the liver caused by chronic liver inflammation or various chronic injuries, and it eventually develops into liver cirrhosis. The process of liver fibrosis is closely related to the immune response, and increasing evidence reveals the role of T lymphocytes, including Th1, Th2, Th17, regulatory T cells, and mucosa‐associated invariant T cells, in liver fibrosis. These immune cells play antifibrotic or profibrotic roles during fibrosis, and the reversal of fibrosis by targeting immune cells has attracted widespread attention. Activation of hepatic stellate cells, which form the core of fibrosis, is regulated by various immune mediators, including various immune cells and their associated cytokines. Therefore, the mechanism of action elicited by each cell type must be further elucidated to provide a basis for the design of new therapeutic targets. The purpose of this review is to summarize the roles and mechanisms of T lymphocytes and their subsets in liver fibrosis and highlight the biomarkers and potential therapeutic targets associated with these cells.

Abstract 1654: Mouse models of hepatocellular carcinoma: A comprehensive and functional preclinical platform for immunotherapy research

Abstract Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related death and accounts for over 80% of primary liver cancer worldwide. Early stage HCC can be treated by local ablation, surgical resection or liver transplantation. Systemic pharmacological options are limited (kinase and immune-checkpoint inhibitors). Most cases of liver cancer occur in the setting of chronic liver diseases. Risk factors include chronic Hepatitis B and C, alcohol addiction and metabolic diseases. HCC is a multistep process comprising chronic liver injury, inflammation, fibrosis/cirrhosis and cancer formation. Therefore, providing palliative and curative options remains a high medical need. And with the recent success of immunotherapies in HCC, mouse models that better recapitulate the human disease and antitumor immune response are needed. In order to better evaluate new preventive and curative treatments of liver cancers we developed complementary and integrated strategies to mimic the liver cancer initiation and progression steps in mouse models. These models involve chemotoxic agents, diet-induced disorders and syngeneic or xenogeneic tumor implantation strategies. We established an orthotopic syngeneic model using Hepa1.6 mouse liver hepatoma cells, characterized through liver index, alpha-fetoprotein measurement in serum and liver, and MRI. The response to chemotherapy (sorafenib) and immunotherapy (anti PD-1, anti-TLR) was also assessed and show moderate to high efficiency. Moreover, a panel of xenograft models including Patient-Derived Xenograft models (PDXs) are available to assess new treatment options in human HCC with regards of the genetic mutations and the variety of etiologies seen in human. But as xenograft models are not completely mimicking the human situation of both immune and liver microenvironment, we have recently initiated the development of a double humanized (immune and liver) transgenic mouse as a better host for human tumor engraftment. During the course of HCC formation, the liver undergoes cycles of inflammation, necrosis with regeneration, fibrosis, cell dysplasia and ultimately HCC. Thus, we developed a model induced by a low dose of streptozotocin and high fat diet regimen. In this model, mice develop metabolic syndrome NASH and fibrosis within 12 weeks and HCC within 16 weeks. Of interest, 100% of male mice develop HCC within 16 weeks, in accordance with studies showing that men had a 2-to 7-fold higher risk of developing HCC in human. Treatment of mice with lenvatinib alone or in combination with anti-PD1 increases survival and reduces tumor burden as shown with reduced liver weight/body weight ratio at 16 weeks. Altogether, these results demonstrate the usefulness of this comprehensive platform of preclinical in vivo HCC models to discover and identify novel therapeutic strategies that could circumvent the progression of liver cancers. Citation Format: Olivier Duchamp, Gael Krysa, Loic Morgand, Hugo Quillery, Robin Artus, Maxime Ramelet, Jeremy Odillard, Peggy Provent, Sylvie Maubant, Caroline Mignard, Fabrice Viviani, Samira Benhamouche-Trouillet. Mouse models of hepatocellular carcinoma: A comprehensive and functional preclinical platform for immunotherapy research [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1654.

Hepatocyte nuclear factor 1A suppresses innate immune response by inducing degradation of TBK1 to inhibit steatohepatitis

Non-alcoholic steatohepatitis (NASH), a progressive form of non-alcoholic fatty liver disease (NAFLD), is characterised by chronic liver inflammation, which can further progress into complications such as liver cirrhosis and NASH-associated hepatocellular carcinoma (HCC) and therefore has become a growing health problem worldwide. The type I interferon (IFN) signaling pathway plays a pivotal role in chronic inflammation; however, the molecular mechanisms underlying NAFLD/NASH from the perspective of innate immune response has not yet been fully explored. In this study, we elucidated the mechanisms of how innate immune response modulates NAFLD/NASH pathogenesis, and demonstrated that hepatocyte nuclear factor-1alpha (HNF1A) was suppressed and the type I IFN production pathway was activated in liver tissues of patients with NAFLD/NASH. Further experiments suggested that HNF1A negatively regulates the TBK1-IRF3 signaling pathway by promoting autophagic degradation of phosphorylated-TBK1, which constrains IFN production, thereby inhibiting the activation of type I IFN signaling. Mechanistically, HNF1A interacts with the phagophore membrane protein LC3 through its LIR-docking sites, and mutations of LIRs (LIR2, LIR3, LIR4, and LIRs) block the HNF1A-LC3 interaction. In addition, HNF1A was identified not only as a novel autophagic cargo receptor but also to specifically induce K33-linked ubiquitin chains on TBK1 at Lys670, thereby resulting in autophagic degradation of TBK1. Collectively, our study illustrates the crucial function of the HNF1A-TBK1 signaling axis in NAFLD/NASH pathogenesis via cross-talk between autophagy and innate immunity.

Hyaluronan synthase 2, a target of miR-200c, promotes carbon tetrachloride-induced acute and chronic liver inflammation via regulation of CCL3 and CCL4

Liver fibrosis occurs during wound healing after repeated liver injury and is characterized by extensive extracellular matrix deposition. We previously identified hyaluronan synthase 2 (HAS2) as a driver of liver fibrosis and hepatic stellate cell (HSC) activation. Developing strategies to suppress HSC activation is key to alleviating liver fibrosis, and HAS2 is an attractive candidate for intervention. To gain insight into the molecular function of HAS2, we investigated its posttranscriptional regulation. We found that miR-200c directly targets the 3’ untranslated regions of HAS2. Moreover, miR-200c and HAS2 were inversely expressed in fibrotic human and mouse livers. After establishing the direct interaction between miR-200c and HAS2, we investigated the functional outcome of regulating HAS2 expression in three murine models: CCl4-induced acute liver injury, CCl4-induced chronic liver fibrosis, and bile duct ligation-induced liver fibrosis. Hepatic Has2 expression was induced by acute and chronic CCl4 treatment. In contrast, miR-200c expression was decreased after CCl4 treatment. HSC-specific Has2 deletion reduced the expression of inflammatory markers and infiltration of macrophages in the models. Importantly, hyaluronidase-2 (HYAL2) but not HYAL1 was overexpressed in fibrotic human and murine livers. HYAL2 is an enzyme that can cleave the extracellular matrix component hyaluronan. We found that low-molecular-weight hyaluronan stimulated the expression of inflammatory genes. Treatment with the HA synthesis inhibitor 4-methylumbelliferone alleviated bile duct ligation-induced expression of these inflammatory markers. Collectively, our results suggest that HAS2 is negatively regulated by miR-200c and contributes to the development of acute liver injury and chronic liver inflammation via hyaluronan-mediated immune signaling.

Discovery of Novel 3-Hydroxyquinazoline-2,4(1H,3H)-Dione Derivatives: A Series of Metal Ion Chelators with Potent Anti-HCV Activities.

Millions of people worldwide suffer from acute or chronic liver inflammation caused by the hepatitis C virus (HCV). Metal ion chelators have achieved widespread success in the development of antiviral drugs. Some inhibitors with metal ion chelating structures have been proven to have good inhibitory activities on non-structural protein 5B (NS5B) polymerase. However, most of the reported metal ion chelators showed poor anti-HCV potency at the cellular level. Hence, we designed and synthesized a series of 3-hydroxyquinazoline-2,4(1H,3H)-dione derivatives with novel metal ion chelating structures. Typical compounds such as 21h, 21k, and 21t showed better anti-HCV activities than ribavirin with EC50 values less than 10 μM. 21t is currently known as one of the metal ion chelators with the best anti-HCV potency (EC50 = 2.0 μM) at the cellular level and has a better therapeutic index (TI > 25) as compared to ribavirin and the reported compound 6. In the thermal shift assay, the representative compounds 21e and 21k increased the melting temperature (Tm) of NS5B protein solution by 1.6 °C and 2.1 °C, respectively, at the test concentration, indicating that these compounds may exert an anti-HCV effect by targeting NS5B. This speculation was also supported by our molecular docking studies and ultraviolet-visible (UV-Vis) spectrophotometry assay, in which the possibility of binding of 3-hydroxyquinazoline-2,4(1H,3H)-diones with Mg2+ in the NS5B catalytic center was observed.

Ethanol extract of Pharbitis nil ameliorates liver fibrosis through regulation of the TGFβ1-SMAD2/3 pathway

Ethnopharmacological relevancePharbitis nil (L.) Choisy is a medicinal herb, and herbal remedies based on its seeds have been used to treat of obesity and liver diseases, including fatty liver and liver cirrhosis in East Asia. Aim of the studyLiver fibrosis is a major cause of morbidity and mortality in patients with chronic liver inflammation such as that caused by non-alcoholic steatohepatitis. However, no effective pharmaceutical treatment for liver fibrosis has been approved. In this study, we aimed to investigate that ethanol extract of pharbitis nil (PNE) alleviates the liver fibrosis. Materials and methodsWe studied the effects of PNE on two preclinical models. Six-week-old male C57BL/6 mice were intraperitoneally injected with CCl4 twice weekly for 6 weeks and then treated with 5 or 10 mg/kg PNE daily from week 3 for weeks. Secondly, mice were fed HFD for 41 weeks and at 35 weeks treated with 5 mg/kg PNE daily for the remaining 6 weeks. In addition, we examined the antifibrotic effects of PNE in primary mouse hepatic stellate cells and LX-2 cells. ResultsPNE treatment ameliorated hepatocyte necrosis, inflammation, and liver fibrosis in CCl4-treated mice and inhibited the progression of liver fibrosis in mice with HFD-induced fibrosis. PNE reduced the expressions of fibrosis markers and SMAD2/3 activations in mouse livers and in TGFβ1-treated primary mouse hepatic stellate and LX-2 cells ConclusionsThis study demonstrates that PNE attenuates liver fibrosis by downregulating TGFβ1-induced SMAD2/3 activation.