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Human APOBEC3G (hA3G) is a cytidine deaminase that restricts replication of certain viruses. We have previously reported that hA3G was a host restriction factor against hepatitis C virus (HCV) replication, and hA3G stabilizers showed a significant inhibitory activity against HCV. However, the molecular mechanism of hA3G against HCV remains unknown. We show in this study that hA3G's C-terminal directly binds HCV non-structural protein NS3 at its C-terminus, which is responsible for NS3's helicase and NTPase activity. Binding of hA3G to the C-terminus of NS3 reduced helicase activity, and therefore inhibited HCV replication. The anti-HCV mechanism of hA3G appeared to be independent of its deamination activity. Although early stage HCV infection resulted in an increase in host hA3G as an intracellular response against HCV replication, hA3G was gradually diminished after a long-term incubation, suggesting an unknown mechanism(s) that protects HCV NS3 from inactivation by hA3G. The process represents, at least partially, a cellular defensive mechanism against HCV and the action is mediated through a direct interaction between host hA3G and HCV NS3. We believe that understanding of the antiviral mechanism of hA3G against HCV might open an interesting avenue to explore hA3G stabilizers as a new class of anti-HCV agents.

Transforming growth factor beta (TGF‐β) plays an important role in the viral liver disease progression via controlling viral propagation and mediating inflammation‐associated responses. However, the antiviral activities and mechanisms of TGF‐β isoforms, including TGF‐β1, TGF‐β2 and TGF‐β3, remain unclear. Here, we demonstrated that all of the three TGF‐β isoforms were increased in Huh7.5 cells infected by hepatitis C virus (HCV), but in turn, the elevated TGF‐β isoforms could inhibit HCV propagation with different potency in infectious HCV cell culture system. TGF‐β isoforms suppressed HCV propagation through interrupting several different stages in the whole HCV life cycle, including virus entry and intracellular replication, in TGF‐β/SMAD signalling pathway–dependent and TGF‐β/SMAD signalling pathway–independent manners. TGF‐β isoforms showed additional anti‐HCV activities when combined with each other. However, the elevated TGF‐β1 and TGF‐β2, not TGF‐β3, could also induce liver fibrosis with a high expression of type I collagen alpha‐1 and α‐smooth muscle actin in LX‐2 cells. Our results showed a new insight into TGF‐β isoforms in the HCV‐related liver disease progression.

Acute pulmonary embolism (APE) with ST-segment elevation and an upward T-wave is rare, and only a few cases have been reported to date. We herein present a case involving a man in his early 70s with an 8-hour history of dyspnea. Serial electrocardiography (ECG) demonstrated ST-segment elevation in leads V1 to V3 with an upward T-wave, laboratory tests revealed a high serum concentration of high-sensitivity cardiac troponin I, and signs of acute myocardial infarction were present. However, emergency coronary angiography revealed normal coronary arteries. A subsequent computed tomography scan of the pulmonary arteries showed findings consistent with APE. The patient’s chest tightness was relieved after catheter-directed thrombolysis. Postoperative ECG showed that the ST-segment in leads V1 to V3 had fallen back and that the T-wave was inverted. The patient was discharged on rivaroxaban therapy. Clinically, the ECG findings of ST-segment elevation and an upward T-wave in APE can be easily misdiagnosed as acute myocardial infarction. Physicians should maintain clinical suspicion through risk stratification to identify APE.

Nonalcoholic fatty liver disease (NAFLD), ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), is a liver disease worldwide without approved therapeutic drugs. Anti-inflammatory and hepatoprotective drug bicyclol and multi-pharmacological active drug berberine, respectively, have shown beneficial effects on NAFLD in murine nutritional models and patients, though the therapeutic mechanisms remain to be illustrated. Here, we investigated the combined effects of bicyclol and berberine on mouse steatosis induced by Western diet (WD), and NASH induced by WD/CCl 4 . The combined use of these was rather safe and better reduced the levels of transaminase in serum and triglycerides and cholesterol in the liver than their respective monotherapy, accompanied with more significantly attenuating hepatic inflammation, steatosis, and ballooning in mice with steatosis and NASH. The combined therapy also significantly inhibited fibrogenesis, characterized by the decreased hepatic collagen deposition and fibrotic surface. As per mechanism, bicyclol enhanced lipolysis and β-oxidation through restoring the p62-Nrf2-CES2 signaling axis and p62-Nrf2-PPARα signaling axis, respectively, while berberine suppressed de novo lipogenesis through downregulating the expression of acetyl-CoA carboxylase and fatty acid synthetase, along with enrichment of lipid metabolism-related Bacteroidaceae (family) and Bacteroides (genus). Of note, the combined use of bicyclol and berberine did not influence each other but enhanced the overall therapeutic role in the amelioration of NAFLD. Conclusion : Combined use of bicyclol and berberine might be a new available strategy to treat NAFLD.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common metabolic disease of the liver, characterized by hepatic steatosis in more than 5% of hepatocytes. However, despite the recent approval of the first drug, resmetirom, for the management of metabolic dysfunction-associated steatohepatitis, decades of target exploration and hundreds of clinical trials have failed, highlighting the urgent need to find new druggable targets for the discovery of innovative drug candidates against MASLD. Here, we found that glutathione S-transferase alpha 1 (GSTA1) expression was negatively associated with lipid droplet accumulation in vitro and in vivo. Overexpression of GSTA1 significantly attenuated oleic acid-induced steatosis in hepatocytes or high-fat diet-induced steatosis in the mouse liver. The hepatoprotective and anti-inflammatory drug bicyclol also attenuated steatosis by upregulating GSTA1 expression. A detailed mechanism showed that GSTA1 directly interacts with fatty acid binding protein 1 (FABP1) and facilitates the degradation of FABP1, thereby inhibiting intracellular triglyceride synthesis by impeding the uptake and transportation of free fatty acids. Conclusion: GSTA1 may be a good target for the discovery of innovative drug candidates as GSTA1 stabilizers or enhancers against MASLD.

Treatment with direct-acting antivirals (DAAs) cures most patients infected with hepatitis C virus (HCV) in the real world. However, some patients, especially those with the underlying advanced liver disease, have a limited reduction of liver injury after achieving a sustained viral response (SVR). Bicyclol was widely used in clinics for the treatment of a variety of liver injuries but with an unknown mechanism for the treatment of hepatitis C. We investigated the anti-inflammatory effects and mechanisms of bicyclol in HCV-infected hepatocytes and further confirmed the putative results in a mouse hepatitis model induced by the coinjection of polyinosinic-polycytidylic acid [poly (I:C)] and D-galactosamine (D-GalN). The results showed that the activation of nuclear factor kappa B (NF-κB) and the subsequent increase of inflammatory factors were directly induced by HCV infection and were persistent after clearance of the virus in Huh7.5 cells. Bicyclol decreased the activation of NF-κB and the levels of inflammatory factors in HCV-infected hepatocytes by inhibiting the activation of the ROS-MAPK-NF-κB pathway, and the effect was synergistic with DAAs in HCV-infected hepatocytes. Bicyclol attenuated the ROS-MAPK-NF-κB axis recovering mitochondrial function without a dependence on dihydronicotinamide adenine dinucleotide phosphate oxidase and superoxide dismutases. The anti-inflammatory effects and mechanism of bicyclol were verified in mouse hepatitis induced by the coinjection of poly(I:C)/D-GalN. Bicyclol directly ameliorates the chronic inflammation caused by HCV infection and might be used with DAAs or after DAA therapy for ultimately curing chronic hepatitis C.

Background: The 2023 Delphi consensus defined metabolic and alcohol-associated liver disease (MetALD), distinguishing between alcohol abuse and moderate consumption. Although alcohol abuse is known to accelerate fatty liver disease progression, the health effects of chronic moderate alcohol intake under different dietary conditions remain unclear. This study aimed to evaluate the impact of moderate alcohol consumption on metabolic phenotypes and gut microbiota/metabolites in lean and obese mice and to propose a model approximating MetALD features. Methods: C57BL/6J mice were fed either a low-fat diet (LFD) or a high-fat diet (HFD) for 12 weeks, with access to 10% (v/v) alcohol in drinking water. Systemic metabolic parameters, liver histopathology, inflammatory and fibrotic markers, gut microbiota composition, and the fecal metabolome were assessed. Results: In LFD-fed mice, 10% alcohol intake induced multiple metabolic alterations, including elevated serum triglycerides, reduced fasting blood glucose, and changes in hepatic lipid metabolism along with steatosis and inflammation—though further studies are required to confirm causality. When combined with HFD, alcohol did not significantly exacerbate most glucose/lipid metabolic disorders but markedly increased hepatic inflammatory cell infiltration and fibrosis progression. Alcohol consistently increased gut microbial α-diversity in both dietary groups, while downregulating beneficial metabolites such as amino acids (e.g., glutamine, histidine), their derivatives, and short-chain fatty acids. Correlation analyses associated these microbial and metabolic changes with altered amino acid/cholesterol metabolism and inflammatory/fibrotic phenotypes, particularly under HFD conditions. Conclusions: These findings suggest that chronic moderate alcohol intake presents distinct risks in lean and obese individuals with different dietary structures.

The cell adhesion between leukocytes and endothelial cells plays an important balanced role in the pathophysiological function, while excessive adhesion caused by etiological agents is associated with the occurrence and development of many acute and chronic diseases. Cell adhesion inhibitors have been shown to have a potential therapeutic effect on these diseases, therefore, efficient and specific inhibitors against cell adhesion are highly desirable. Here, using lipopolysaccharide-induced human umbilical vein endothelial cells (HUVECs) and calcein-AM-labeled human monocytic cell THP-1, we established a high-throughput screening model for cell adhesion inhibitors with excellent model evaluation parameters. Using the drug repurposing strategy, we screened out lifitegrast, a potent cell adhesion inhibitor, which inhibited cell adhesion between HUVEC and THP-1 cells by directly interrupting the adhesion interaction between HUVEC and THP-1 cells and showed a strong therapeutic effect on the mouse acute liver injury induced by poly (I:C)/D-GalN. Therefore, the screening model is suitable for screening and validating cell adhesion inhibitors, which will promote the research and development of inhibitors for the treatment of diseases caused by excessive cell adhesion.

Autophagy and immune response are two defense systems that human-body uses against viral infection. Previous studies documented that some viral mechanisms circumvented host immunity mechanisms and hijacked autophagy for its replication and survival. Here, we focus on interactions between autophagy mechanism and innate-immune-response in HCV-subgenomic replicon cells to find a mechanism linking the two pathways. We report distinct effects of two autophagy-related protein ATG10s on HCV-subgenomic replication. ATG10, a canonical long isoform in autophagy process, can facilitate HCV-subgenomic replicon amplification by promoting autophagosome formation and by combining with and detaining autophagosomes in cellular periphery, causing impaired autophagy flux. ATG10S, a non-canonical short isoform of ATG10 proteins, can activate expression of IL28A/B and immunity genes related to viral ds-RNA including ddx-58 , tlr-3 , tlr- 7, irf-3 and irf-7 , and promote autophagolysosome formation by directly combining and driving autophagosomes to perinuclear region where lysosomes gather, leading to lysosomal degradation of HCV-subgenomic replicon in HepG2 cells. ATG10S also can suppress infectious HCV virion replication in Huh7.5 cells. Another finding is that IL28A protein directly conjugates ATG10S and helps autophagosome docking to lysosomes. ATG10S might be a new host factor against HCV replication, and as a target for screening chemicals with new anti-virus mechanisms.

Interferon lambda-2 (IL28A) has a wide antiviral effect with fewer side-effects. Autophagy is a host mechanism to maintain intracellular homeostasis and defends invasion of pathogenic microorganisms. HCV NS5A can disable host defense systems to support HCV replication. Thus, molecular mechanism of interaction among interferon lambda, autophagy, and HCV was concerned and explored in this study. We report that HCV NS5A activated an incomplete autophagy by promoting the autophagic ubiquitylation-like enzymes ATG3, ATG5, ATG7, ATG10, and autophagosome maker LC3B, but blocked autophagy flux; IL28A bound to NS5A at NS5A-ISDR region, and degraded HCV-NS5A by promoting autolysosome formations in HepG2 cells. A software prediction of IL28A protein conformation indicated a potential structure of IL28A homotetramer; the first α-helix of IL28A locates in the interfaces among the four IL28A chains to maintain IL28A homotetrameric conformation. Co-IP and cell immunofluorescence experiments with sequential deletion mutants demonstrate that IL28A preferred a homotetramer conformation to a monomer in the cells; the IL28A homotetramer is positively correlated with autolysosomal degradation of HCV NS5A and the other HCV proteins. Summarily, the first α-helix of IL28A protein is the key domain for maintaining IL28A homotetramer which is required for promoting formation of autolysosomes and degradation of HCV proteins in vitro.