Macrophage Phenotypes and Hepatitis B Virus Infection

Activation of the cGAS-STING pathway by viral dsDNA leading to M1 polarization of macrophages mediates antiviral activity against hepatitis B virus

BACKGROUND AND AIMS

Activation of the cGAS-STING pathway induces the production of type I interferons, initiating the antiviral immune response, which contributes to the clearance of pathogens. Previous studies have shown that STING agonists promote hepatitis B virus (HBV) clearance; however, few studies have investigated the effect of activating the cGAS-STING pathway in macrophages on HBV.

METHODS

The polarization status of HBV particle-stimulated RAW264.7 macrophages was analyzed. After stimulation with HBV particles, the analysis focused on determining whether the DNA sensors in RAW264.7 macrophages recognized the viral double-stranded DNA (dsDNA) and evaluating the activation of the cGAS-STING pathway. Coculture of mouse macrophages and hepatocytes harboring HBV was used to study the antiviral activity of HBV-stimulated RAW264.7 macrophages.

RESULTS

After stimulation with HBV particles, HBV relaxed circular DNA (rcDNA) was detected in RAW264.7 macrophages, and the protein expression of phospho-STING, phospho-TBK1, and phospho-IRF3 in the STING pathway was increased, as shown by Western blot analysis, which revealed that M1 polarization of macrophages was caused by increased expression of CD86. RT-PCR analyses revealed elevated expression of M1 macrophage polarization-associated cytokines such as TNFα, IL-1β, iNOS, and IFNα/β. In the coculture experiment, both HBsAg and HBeAg expression levels were significantly decreased in AML12-HBV1.3 cells cocultured with the supernatants of HBV-stimulated RAW264.7 macrophages.

CONCLUSION

The results suggest that macrophages can endocytose HBV particles. Additionally, viral dsDNA can be recognized by DNA pattern recognition receptors, which in turn activate the cGAS-STING pathway, promoting the M1 polarization of macrophages, while no significant M2 polarization is observed. Macrophages stimulated with HBV particles exhibit enhanced antiviral activity against HBV.

Single-cell RNA sequencing reveals the immunoregulatory roles of PegIFN-α in patients with chronic hepatitis B

BACKGROUND AND AIMS

Chronic hepatitis B (CHB) is caused by HBV infection and affects the lives of millions of people worldwide by causing liver inflammation, cirrhosis, and liver cancer. Interferon-alpha (IFN-α) therapy is a conventional immunotherapy that has been widely used in CHB treatment and achieved promising therapeutic outcomes by activating viral sensors and interferon-stimulated genes (ISGs) suppressed by HBV. However, the longitudinal landscape of immune cells of CHB patients and the effect of IFN-α on the immune system are not fully understood.

APPROACH AND RESULTS

Here, we applied single-cell RNA sequencing (scRNA-seq) to delineate the transcriptomic landscape of peripheral immune cells in CHB patients before and after PegIFN-α therapy. Notably, we identified three CHB-specific cell subsets, pro-inflammatory (Pro-infla) CD14+ monocytes, Pro-infla CD16+ monocytes and IFNG+ CX3CR1- NK cells, which highly expressed proinflammatory genes and positively correlated with HBsAg. Furthermore, PegIFN-α treatment attenuated percentages of hyperactivated monocytes, increased ratios of long-lived naive/memory T cells and enhanced effector T cell cytotoxicity. Finally, PegIFN-α treatment switched the transcriptional profiles of entire immune cells from TNF-driven to IFN-α-driven pattern and enhanced innate antiviral response, including virus sensing and antigen presentation.

CONCLUSIONS

Collectively, our study expands the understanding of the pathological characteristics of CHB and the immunoregulatory roles of PegIFN-α, which provides a new powerful reference for the clinical diagnosis and treatment of CHB.

Regulation of Mitochondrial Metabolism by Hepatitis B Virus

Mitochondria play important roles in the synthesis of ATP, the production of reactive oxygen species, and the regulation of innate immune response and apoptosis. Many viruses perturb mitochondrial activities to promote their replication and cause cell damage. Hepatitis B virus (HBV) is a hepatotropic virus that can cause severe liver diseases, including cirrhosis and hepatocellular carcinoma (HCC). This virus can also alter mitochondrial functions and metabolism to promote its replication and persistence. In this report, we summarize recent research progress on the interaction between HBV and mitochondrial metabolism, as well as the effect this interaction has on HBV replication and persistence.

Single-cell RNA sequencing of liver fine-needle aspirates captures immune diversity in the blood and liver in chronic hepatitis B patients

BACKGROUND AND AIMS

HBV infection is restricted to the liver, where it drives exhaustion of virus-specific T and B cells and pathogenesis through dysregulation of intrahepatic immunity. Our understanding of liver-specific events related to viral control and liver damage has relied almost solely on animal models, and we lack useable peripheral biomarkers to quantify intrahepatic immune activation beyond cytokine measurement. Our objective was to overcome the practical obstacles of liver sampling using fine-needle aspiration and develop an optimized workflow to comprehensively compare the blood and liver compartments within patients with chronic hepatitis B using single-cell RNA sequencing.

APPROACH AND RESULTS

We developed a workflow that enabled multi-site international studies and centralized single-cell RNA sequencing. Blood and liver fine-needle aspirations were collected, and cellular and molecular captures were compared between the Seq-Well S 3 picowell-based and the 10× Chromium reverse-emulsion droplet-based single-cell RNA sequencing technologies. Both technologies captured the cellular diversity of the liver, but Seq-Well S 3 effectively captured neutrophils, which were absent in the 10× dataset. CD8 T cells and neutrophils displayed distinct transcriptional profiles between blood and liver. In addition, liver fine-needle aspirations captured a heterogeneous liver macrophage population. Comparison between untreated patients with chronic hepatitis B and patients treated with nucleoside analogs showed that myeloid cells were highly sensitive to environmental changes while lymphocytes displayed minimal differences.

CONCLUSIONS

The ability to electively sample and intensively profile the immune landscape of the liver, and generate high-resolution data, will enable multi-site clinical studies to identify biomarkers for intrahepatic immune activity in HBV and beyond.

HBV suppresses macrophage immune responses by impairing the TCA cycle through the induction of CS/PDHC hyperacetylation

BACKGROUND

It is now understood that HBV can induce innate and adaptive immune response disorders by affecting immunosuppressive macrophages, resulting in chronic HBV infection. However, the underlying mechanism is not fully understood. Dysregulated protein acetylation can reportedly influence the differentiation and functions of innate immune cells by coordinating metabolic signaling. This study aims to assess whether HBV suppresses macrophage-mediated innate immune responses by affecting protein acetylation and to elucidate the underlying mechanisms of HBV immune escape.

METHODS

We investigated the effect of HBV on the acetylation levels of human THP-1 macrophages and identified potential targets of acetylation that play a role in glucose metabolism. Metabolic and immune phenotypes of macrophages were analyzed using metabolomic and flow cytometry techniques. Western blot, immunoprecipitation, and immunofluorescence were performed to measure the interactions between deacetylase and acetylated targets. Chronic HBV persistent infected mice were established to evaluate the role of activating the tricarboxylic acid (TCA) cycle in macrophages for HBV clearance.

RESULTS

Citrate synthase/pyruvate dehydrogenase complex hyperacetylation in macrophages after HBV stimulation inhibited their enzymatic activities and was associated with impaired TCA cycle and M2-like polarization. HBV downregulated Sirtuin 3 (SIRT3) expression in macrophages by means of the toll-like receptor 2 (TLR2)-NF-κB- peroxisome proliferatoractivated receptor γ coactivator 1α (PGC-1α) axis, resulting in citrate synthase/pyruvate dehydrogenase complex hyperacetylation. In vivo administration of the TCA cycle agonist dichloroacetate inhibited macrophage M2-like polarization and effectively reduced the number of serum HBV DNA copies.

CONCLUSIONS

HBV-induced citrate synthase/pyruvate dehydrogenase complex hyperacetylation negatively modulates the innate immune response by impairing the TCA cycle of macrophages. This mechanism represents a potential therapeutic target for controlling HBV infection.

Immunomodulatory and Antiviral Therapy Improved Functional Cure Rate in CHB Patients with High HBsAg Level Experienced NA

Background and Aims

A functional cure, or hepatitis B virus (HBV) surface antigen (HBsAg) loss, is difficult to achieve in patients with hepatitis B virus e antigen (HBeAg)-positive chronic hepatitis B. The HBV vaccine and granulocyte-macrophage colony-stimulating factor (GM-CSF) have been reported to help reduce HBsAg levels and promote HBsAg loss. In this prospective randomized trial, we evaluated HBsAg loss in patients receiving pegylated interferon-α2b (PEGIFN-α2b) and tenofovir disoproxil fumarate (TDF), with and without GM-CSF and HBV vaccination.

Methods

A total of 287 patients with HBeAg positive chronic hepatitis B and seroconversion after nucleot(s)ide analog treatment were assigned randomly to three treatment groups for 48 weeks, TDF alone (control), PEGIFN-α2b + TDF, and PEGIFN-α2b + TDF + GM-CSF + HBV vaccine. The primary endpoints were the proportions of patients with HBsAg loss and seroconversion at 48 and 72 weeks.

Results

The cumulative HBsAg loss rates in the control, PEGIFN-α2b + TDF, and PEGIFN-α2b + TDF + GM-CSF + HBV vaccine groups at week 48 were 0.0%, 28.3%, and 41.1%, respectively. The cumulative HBsAg seroconversion rates in these groups at week 48 were 0.0%, 21.7%, and 33.9%, respectively. Multivariate regression analysis showed that GM-CSF use plus HBV vaccination was significantly associated with HBsAg loss (p=0.017) and seroconversion (p=0.030).

Conclusions

In patients with HBeAg-positive chronic hepatitis B and seroconversion after nucleot(s)ide analog treatment, immunomodulatory/antiviral treatment regimens effectively improved HBsAg loss, and the regimen including GM-CSF and HBV vaccination was most effective.

Multi-omics profiling of primary hepatic stellate cells from advanced liver fibrosis patients reveals distinctive molecular signatures

BACKGROUND AND AIM

Hepatic fibrosis is a common pathogenic outcome of almost all chronic liver diseases and a growing public health problem globally. However, the key genes or proteins driving liver fibrosis and cirrhosis are not well understood. We aimed to identify novel hepatic fibrosis genes of human primary hepatic stellate cells (HSCs).

METHODS

Human primary HSCs were isolated from surgically resected advanced fibrosis liver tissues (n = 6) and surgical resection of normal liver tissue around hemangioma (n = 5). Differences in the expression levels of mRNA and proteins from HSCs in advanced fibrosis group and the control group were analyzed using RNA sequencing and mass spectrometry as transcriptomic and proteomic approaches. The obtained biomarkers were further validated through real-time quantitative polymerase chain reaction (RT-qPCR), immunofluorescence, and Western blot.

RESULTS

A total of 2156 transcripts and 711 proteins were found to be differently expressed between the advanced fibrosis group and the control group patients. The Venn diagram shows that a total of 96 upregulated molecules are overlapped in both the transcriptomic and proteomic datasets. Gene Ontology enrichment analysis and Kyoto Encyclopedia of Genes and Genomes analysis indicated that those overlapped genes were mainly involved in wound healing, cell adhesion regulation, and actin binding, which reflects the major biological conversions in liver cirrhosis process. Pyruvate kinase M2 and EH domain-containing 2 were identified as potential new markers for advanced liver cirrhosis, which have been validated in primary human HSCs and in vitro cellular hepatic fibrosis model Lieming Xu-2 (LX-2) cells.

CONCLUSIONS

Our results revealed the major transcriptomic and proteomic changes during liver cirrhosis process and identified new biomarkers and potential therapeutic targets for advanced liver fibrosis.

Traditional Chinese medicine invigorating the spleen and kidney promotes HBsAg seroclearance in the mouse model

Traditional Chinese medicine (TCM) is often used as an adjuvant or alternative therapy for abnormal liver biochemistry or liver fibrosis associated with chronic hepatitis B (CHB). However, the role of TCM in HBsAg seroclearance remains unclear. We aimed at exploring the role and possible mechanisms of TCM in HBsAg seroclearance. Fifteen widely used TCM granules invigorating the spleen and kidneys were screened. C57BL/6J mice were administered daily with TCM granules by gavage for 1 week. The effect of TCM on the M1 polarization of macrophages was measured using a CD86 assay. According to the principles of formulating prescriptions, three single TCM with the most noticeable effect on M1 polarization, accompanied by two other TCM granules, were used to develop a TCM formula. The hepatitis B virus-expressing mouse model was constructed by hydrodynamic injection of the pAAV/HBV1.2 plasmid. Hepatitis B virus-expressing mice were gavaged daily with phosphate-buffered saline (PBS), TCM formula, or Codonopsis Radix, for 1 week. HBsAg, HBeAg, and hepatitis B virus DNA levels were measured. In addition, gut microbiota was profiled using 16S rDNA sequencing. Several TCM granules showed significant effects on M1 polarization. The TCM formula accelerated HBsAg seroclearance compared with the Codonopsis Radix and PBS groups. Intrahepatic M1 polarization, as indicated by flow cytometry and immunohistochemistry, was induced in the TCM formula and Codonopsis Radix groups. The abundance of Alloprevotella significantly increased in the TCM formula and Codonopsis Radix groups. These results demonstrate that the TCM formula for invigorating the spleen and kidney can accelerate HBsAg seroclearance. This effect can be attributed, at least in part, to M1 polarization of intrahepatic macrophages.

Activation of Kupffer cells in NAFLD and NASH: mechanisms and therapeutic interventions

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are emerging as the leading causes of liver disease worldwide. These conditions can lead to cirrhosis, liver cancer, liver failure, and other related ailments. At present, liver transplantation remains the sole treatment option for end-stage NASH, leading to a rapidly growing socioeconomic burden. Kupffer cells (KCs) are a dominant population of macrophages that reside in the liver, playing a crucial role in innate immunity. Their primary function includes phagocytosing exogenous substances, presenting antigens, and triggering immune responses. Moreover, they interact with other liver cells during the pathogenesis of NAFLD, and this crosstalk may either delay or exacerbate disease progression. Stimulation by endogenous signals triggers the activation of KCs, resulting in the expression of various inflammatory factors and chemokines, such as NLRP3, TNF-α, IL-1B, and IL-6, and contributing to the inflammatory cascade. In the past 5 years, significant advances have been made in understanding the biological properties and immune functions of KCs in NAFLD, including their interactions with tissue molecules, underlying molecular mechanisms, signaling pathways, and relevant therapeutic interventions. Having a comprehensive understanding of these mechanisms and characteristics can have enormous potential in guiding future strategies for the prevention and treatment of NAFLD.

Insights into the impact of hepatitis B virus on hepatic stellate cell activation

During chronic hepatitis B virus (HBV) infection, hepatic fibrosis is a serious pathological condition caused by virus-induced liver damage. The activation of hepatic stellate cells (HSCs) is a central event in the occurrence and progression of liver fibrosis. Although accumulating evidence has shown that HBV directly stimulates HSC activation, whether the virus infects and replicates in HSCs remains controversial. Inflammation is one of the obvious characteristics of chronic HBV infection, and it has been demonstrated that persistent inflammation has a predominant role in triggering and maintaining liver fibrosis. In particular, the regulation of HSC activation by HBV-related hepatocytes via various inflammatory modulators, including TGF-β and CTGF, in a paracrine manner has been reported. In addition to these inflammation-related molecules, several inflammatory cells are essential for the progression of HBV-associated liver fibrosis. Monocytes, macrophages, Th17 cells, NK cells, as well as NKT cells, participate in the modulation of HBV-related liver fibrosis by interacting with HSCs. This review summarizes current findings on the effects of HBV and the relevant molecular mechanisms involved in HSC activation. Because HSC activation is essential for liver fibrosis, targeting HSCs is an attractive therapeutic strategy to prevent and reverse hepatic fibrosis induced by HBV infection. Video abstract.

New insights into hepatitis B virus lymphotropism: Implications for HBV-related lymphomagenesis

HBV is one of the most widespread hepatitis viruses worldwide, and a correlation between chronic infection and liver cancer has been clearly reported. The carcinogenic capacity of HBV has been reported for other solid tumors, but the largest number of studies focus on its possible lymphomagenic role. To update the correlation between HBV infection and the occurrence of lymphatic or hematologic malignancies, the most recent evidence from epidemiological and in vitro studies has been reported. In the context of hematological malignancies, the strongest epidemiological correlations are with the emergence of lymphomas, in particular non-Hodgkin’s lymphoma (NHL) (HR 2.10 [95% CI 1.34-3.31], p=0.001) and, more specifically, all NHL B subtypes (HR 2.14 [95% CI 1.61-2.07], p<0.001). Questionable and unconfirmed associations are reported between HBV and NHL T subtypes (HR 1.11 [95% CI 0.88-1.40], p=0.40) and leukemia. The presence of HBV DNA in peripheral blood mononuclear cells has been reported by numerous studies, and its integration in the exonic regions of some genes is considered a possible source of carcinogenesis. Some in vitro studies have shown the ability of HBV to infect, albeit not productively, both lymphomonocytes and bone marrow stem cells, whose differentiation is halted by the virus. As demonstrated in animal models, HBV infection of blood cells and the persistence of HBV DNA in peripheral lymphomonocytes and bone marrow stem cells suggests that these cellular compartments may act as HBV reservoirs, allowing replication to resume later in the immunocompromised patients (such as liver transplant recipients) or in subjects discontinuing effective antiviral therapy. The pathogenetic mechanisms at the basis of HBV carcinogenic potential are not known, and more in-depth studies are needed, considering that a clear correlation between chronic HBV infection and hematological malignancies could benefit both antiviral drugs and vaccines.

Overview of the development of HBV small molecule inhibitors

Like tuberculosis and Acquired Immune Deficiency Syndrome (AIDS), hepatitis B is a globally recognized major public health threat. Although there are many small-molecule drugs for the treatment of hepatitis B, the approved drugs cannot eradicate the pathogenic culprit covalently closed circular DNA in patients, so the patients need long-term medication to control HBV amplification. Driven by a high unmet medical need, many pharmaceutical companies and research institutions have been engaged in the development of anti-HBV drugs to achieve a functional cure for chronic hepatitis B as soon as possible. This review summarizes the pathogenesis of hepatitis B virus and the research progress in the development of anti-HBV small molecule drugs, and introduces the cccDNA formation and transcription inhibitors and core inhibitors in detail, especially emphasizes the role of chinese herbal medicine in the treatment of chronic hepatitis B. Furthermore, this review proposes three potential strategies for cccDNA eradication in the future. We believe this review will provide meaningful guidance to achieve a functional cure for viral hepatitis B in the future.

MiR-155 regulates M2 polarization of hepatitis B virus-infected tumour-associated macrophages which in turn regulates the malignant progression of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) initiated by hepatitis B virus (HBV) infection is a complicated process. MiR-155 can alter the immune microenvironment to affect the host's anti-infective ability. This study investigated the mechanism by which miR-155 affects tumour-associated macrophage (TAM) polarization at a molecular level, thus affecting the malignant progression of HBV⁺ HCC. MiR-155 and TAM-related cytokine expression were analysed by qRT-PCR. The distribution of TAMs was detected by immunohistochemistry. The effect of the aberrant miR-155 expression on macrophage polarization was examined by flow cytometry. The targeted relationship was verified by dual-luciferase assay, and the protein level of src homology 2 domain-containing inositol polyphosphate 5-phosphatase 1 (SHIP1) was detected by western blot. The proliferation of HCC cells was examined by CCK-8 and colony formation assays. Invasion and migration of HCC cells were detected by transwell assay. In HBV⁺ HCC tissues, miR-155 was significantly highly expressed and the number of CD206-positive TAM (CD206⁺ TAM) and CD68-positive TAM (CD68⁺ TAM) were higher than those in HBV^- HCC tissues. In addition, miR-155 overexpression significantly promoted M2-type macrophage polarization, whilst miR-155 silencing expression significantly promoted M1-type macrophage polarization. Besides, the miR-155/SHIP1 axis accelerated HCC cell invasion, proliferation and migration by inducing M2-type macrophage polarization. MiR-155 accelerates HCC cell proliferation, migration and invasion by targeting SHIP1 expression and inducing macrophage M2 polarization. This finding provides new insights into the development of novel therapeutic strategies for combatting HBV⁺ HCC and a new reference for exploring anti-tumour immunotherapy.

Hepatocyte-Derived Prostaglandin E2-Modulated Macrophage M1-Type Polarization via mTOR-NPC1 Axis-Regulated Cholesterol Transport from Lysosomes to the Endoplasmic Reticulum in Hepatitis B Virus x Protein-Related Nonalcoholic Steatohepatitis

Lipid metabolic dysregulation and liver inflammation have been reported to be associated with nonalcoholic steatohepatitis (NASH), but the underlying mechanisms remain unclear. Hepatitis B virus x protein (HBx) is a risk factor for NASH. Based on metabolomic and transcriptomic screens and public database analysis, we found that HBx-expressing hepatocyte-derived prostaglandin E2 (PGE2) induced macrophage polarization imbalance via prostaglandin E2 receptor 4 (EP4) through in vitro, ex vivo, and in vivo models. Here, we revealed that the M1-type polarization of macrophages induced by endoplasmic reticulum oxidoreductase-1-like protein α (ERO1α)-dependent endoplasmic reticulum stress was associated with the HBx-related hepatic NASH phenotype. Mechanistically, HBx promoted Niemann-Pick type C1 (NPC1)/oxysterol-binding protein-related protein 5 (ORP5)-mediated cholesterol transport from the lysosome to the endoplasmic reticulum via mammalian target of rapamycin (mTOR) activation. This study provides a novel basis for screening potential biomarkers in the macrophage mTOR-cholesterol homeostasis-polarization regulatory signaling pathway and evaluating targeted interventions for HBx-associated NASH.

Codelivery of HBx-siRNA and Plasmid Encoding IL-12 for Inhibition of Hepatitis B Virus and Reactivation of Antiviral Immunity

Chronic hepatitis B is a critical cause of many serious liver diseases such as hepatocellular carcinoma (HCC). The main challenges in hepatitis B treatment include the rebound of hepatitis B virus (HBV)-related antigen levels after drug withdrawal and the immunosuppression caused by the virus. Herein, we demonstrate that the HBV-related antigen can be effectively inhibited and antiviral immunity can be successfully reactivated through codelivery of the small interfering RNA (siRNA) targeting HBV X protein (HBx) and the plasmid encoding interleukin 12 (pIL-12) to hepatocytes and immune cells. After being treated by the siRNA/pIL-12 codelivery system, HBx mRNA and hepatitis B surface antigen (HBsAg) are dramatically reduced in HepG2.215 cells. More importantly, the downregulated CD47 and programmed death ligand 1 (PD-L1) and the upregulated interferon-β promoter stimulator-1 (IPS-1), retinoic acid-inducible gene-1 (RIG-1), CD80, and human leukocyte antigen-1 (HLA-1) in treated HepG2.215 cells indicate that the immunosuppression is reversed by the codelivery system. Furthermore, the codelivery system results in inhibition of extracellular regulated protein kinases (ERK) and phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt) pathways, as well as downregulation of B-cell lymphoma-2 (Bcl-2) and upregulation of p53, implying its potential in preventing the progression of HBV-induced HCC. In addition, J774A.1 macrophages treated by the codelivery system were successfully differentiated into the M1 phenotype and expressed enhanced cytokines with anti-hepatitis B effects such as interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α). Therefore, we believe that codelivery of siRNA and pIL-12 can effectively inhibit hepatitis B virus, reverse virus-induced immunosuppression, reactivate antiviral immunity, and hinder the progression of HBV-induced hepatocellular carcinoma. This investigation provides a promising approach for the synergistic treatment of HBV infection.

Proliferation of CD11b+ myeloid cells induced by TLR4 signaling promotes hepatitis B virus clearance

BACKGROUNDS AND AIMS

Effective immune response plays a key role in the clearance of hepatitis B virus (HBV). However, the specific role of innate immune response in the clearance of virus is still unclear. Here we investigated the effect of TLR4 signaling on the proliferation and differentiation of CD11b+ myeloid cells, which contributes to virus clearance.

METHODS

C57BL/6 mice were pretreated with TLR4 ligand lipopolysaccharide by intraperitoneal injection. Hydrodynamic injection (HI) was performed to establish HBV-replicated mice. The viremia was monitored. The immune cells were isolated from liver and spleen of the mice. The proliferation and differentiation of CD11b+ myeloid cells were analyzed by flow cytometry. The changes of CD11b+ myeloid cells and its role in virus clearance during HBV infection after LPS stimulation were analyzed.

RESULTS

LPS stimulation induced the proliferation of CD11b+ myeloid cells which differentiated into neutrophils and inflammatory mononuclear macrophages. The expression of F4/80 protein on the surface of mononuclear macrophages in the liver of LPS-stimulated mice was significantly lower than that of control. It indicated that intrahepatic Kupffer cells were significantly decreased in the LPS-stimulated mice, which promoted the clearance of virus.

CONCLUSION

LPS stimulation induces the proliferation of CD11b+ myeloid cells that differentiate into inflammatory neutrophils and monocytes, which inhibits HBV replication. And the decrease of intrahepatic Kupffer cells also contributes to the clearance of HBV during HBV infection.

Interplay between chronic hepatitis B and atherosclerosis: Innovative perspectives and theories

Elaboration of carotid atherosclerosis in the setting of hepatitis B virus (HBV) infection should emphasize the significance of extrahepatic manifestations of the infection pathogenesis. Diverse processes comprise the pathoevolution of HBV infection, rendering it a multi-systemic disease in its essence. Our work not only exemplified atherosclerosis as an often-underestimated contributor to the severity of HBV infection but has also highlighted the bidirectional relationship between the two. Therefore, it is suggested that HBV-induced inflammation is one of the root causes of atherosclerosis, which in turn has a consequent effect on the severity of the chronic infection disease state, creating a vicious cycle. Additionally, we coupled prior data with the current concepts of HBV infection to postulate intriguing perspectives and theories.

Macrophage Polarization and Its Role in Liver Disease

Macrophages are important immune cells in innate immunity, and have remarkable heterogeneity and polarization. Under pathological conditions, in addition to the resident macrophages, other macrophages are also recruited to the diseased tissues, and polarize to various phenotypes (mainly M1 and M2) under the stimulation of various factors in the microenvironment, thus playing different roles and functions. Liver diseases are hepatic pathological changes caused by a variety of pathogenic factors (viruses, alcohol, drugs, etc.), including acute liver injury, viral hepatitis, alcoholic liver disease, metabolic-associated fatty liver disease, liver fibrosis, and hepatocellular carcinoma. Recent studies have shown that macrophage polarization plays an important role in the initiation and development of liver diseases. However, because both macrophage polarization and the pathogenesis of liver diseases are complex, the role and mechanism of macrophage polarization in liver diseases need to be further clarified. Therefore, the origin of hepatic macrophages, and the phenotypes and mechanisms of macrophage polarization are reviewed first in this paper. It is found that macrophage polarization involves several molecular mechanisms, mainly including TLR4/NF-κB, JAK/STATs, TGF-β/Smads, PPARγ, Notch, and miRNA signaling pathways. In addition, this paper also expounds the role and mechanism of macrophage polarization in various liver diseases, which aims to provide references for further research of macrophage polarization in liver diseases, contributing to the therapeutic strategy of ameliorating liver diseases by modulating macrophage polarization.

Study on mechanism of matrine in treatment of COVID-19 combined with liver injury by network pharmacology and molecular docking technology

The aim of the present study was to investigate the pharmacological mechanism of matrine in treatment of COVID-19 combined with liver injury. Potential targets related to matrine, COVID-19 and liver injury were identified from several databases. We constructed PPI network and screened the core targets according to the degree value. Then, GO and KEGG enrichment were carried out. Molecular docking technology was used to verify the affinity between matrine and the crystal structure of core target protein. Finally, real-time RT-PCR was used to detect the effects of matrine on hub gene expression in liver tissue of liver injury mice and lung tissue of lung injury mice to further confirm the results of network pharmacological analysis. The results show that six core targets including AKT1, TP53, TNF, IL6, BCL2L1 and ATM were identified. The potential therapeutic mechanism of matrine on COVID-19 combined with liver injury is closely related to regulate antiviral process, improve immune system and regulate the level of inflammatory factors. Molecular docking showed that matrine could spontaneously bind to the receptor protein and had strong binding force. Real-time RT-PCR demonstrated that matrine could significantly reduce the expression of AKT1, TP53, TNF, IL6 and ATM in mice with liver injury or lung injury (P < 0.05), and increase the expression of BCL2L1 to a certain extent (P > 0.05). Our results indicate that matrine can achieve simultaneous intervention of COVID-19 combined with liver injury by multi-dimensional pharmacological mechanism.

Progression on the Roles and Mechanisms of Tumor-Infiltrating T Lymphocytes in Patients With Hepatocellular Carcinoma

Primary liver cancer (PLC) is one of the most common malignancies in China, where it ranks second in mortality and fifth in morbidity. Currently, liver transplantation, hepatic tumor resection, radiofrequency ablation, and molecular-targeted agents are the major treatments for hepatocellular carcinoma (HCC). Overall, HCC has a poor survival rate and a high recurrence rate. Tumor-infiltrating lymphocytes (TILs) have been discovered to play essential roles in the development, prognosis, and immunotherapy treatment of HCC. As the major component cells of TILs, T cells are also proved to show antitumor and protumor effects in HCC. Foxp3+, CD8+, CD3+, and CD4+ T lymphocytes are the broadly studied subgroups of TILs. This article reviews the roles and mechanisms of different tumor-infiltrating T lymphocyte subtypes in HCC.

Antioxidant Role of Kaempferol in Prevention of Hepatocellular Carcinoma

Reactive oxygen species (ROS) are noxious to cells because their increased level interacts with the body's defense mechanism. These species also cause mutations and uncontrolled cell division, resulting in oxidative stress (OS). Prolonged oxidative stress is responsible for incorrect protein folding in the endoplasmic reticulum (ER), causing a stressful condition, ER stress. These cellular stresses (oxidative stress and ER stress) are well-recognized biological factors that play a prominent role in the progression of hepatocellular carcinoma (HCC). HCC is a critical global health problem and the third leading cause of cancer-related mortality. The application of anti-oxidants from herbal sources significantly reduces oxidative stress. Kaempferol (KP) is a naturally occurring, aglycone dietary flavonoid that is present in various plants (Crocus sativus, Coccinia grandis, Euphorbia pekinensis, varieties of Aloe vera, etc.) It is capable of interacting with pleiotropic proteins of the human body. Efforts are in progress to develop KP as a potential candidate to prevent HCC with no adverse effects. This review emphasizes the molecular mechanism of KP for treating HCC, targeting oxidative stress.

Liver transplantation for post-COVID-19 sclerosing cholangitis

Since identified in December 2019, COVID-19 has remained a pandemic across the globe. Although primarily a respiratory illness, the impact of COVID-19 on other end organs has been increasingly identified. The effect of COVID-19 on the liver has yet to be completely understood. We describe a case of COVID-19 leading to end-stage cholangiopathy and deceased donor liver transplantation (LT). A 64-year-old man with no underlying respiratory or liver disease presented with acute respiratory distress secondary to COVID-19 pneumonia requiring intubation. Several months after resolution of his respiratory symptoms, he developed transaminitis, worsening jaundice, abdominal pain and dark-coloured urine. Hepatic function remained severely impaired warranting LT 259 days following his initial COVID-19 diagnosis. Explant pathology demonstrated diffuse hepatic injury, onion skinning of the bile ducts and bile duct loss in scattered portal tracts. As more patients develop COVID-19-related complications, we suggest LT as an option for COVID-19-related end-stage liver disease.

Hepatitis B virus infection modeling using multi-cellular organoids derived from human induced pluripotent stem cells

Chronic infection with hepatitis B virus (HBV) remains a global health concern despite the availability of vaccines. To date, the development of effective treatments has been severely hampered by the lack of reliable, reproducible, and scalable in vitro modeling systems that precisely recapitulate the virus life cycle and represent virus-host interactions. With the progressive understanding of liver organogenesis mechanisms, the development of human induced pluripotent stem cell (iPSC)-derived hepatic sources and stromal cellular compositions provides novel strategies for personalized modeling and treatment of liver disease. Further, advancements in three-dimensional culture of self-organized liver-like organoids considerably promote in vitro modeling of intact human liver tissue, in terms of both hepatic function and other physiological characteristics. Combined with our experiences in the investigation of HBV infections using liver organoids, we have summarized the advances in modeling reported thus far and discussed the limitations and ongoing challenges in the application of liver organoids, particularly those with multi-cellular components derived from human iPSCs. This review provides general guidelines for establishing clinical-grade iPSC-derived multi-cellular organoids in modeling personalized hepatitis virus infection and other liver diseases, as well as drug testing and transplantation therapy.

The peripheral and core regions of virus-host network of COVID-19

Two thousand nineteen novel coronavirus SARS-CoV-2, the pathogen of COVID-19, has caused a catastrophic pandemic, which has a profound and widespread impact on human lives and social economy globally. However, the molecular perturbations induced by the SARS-CoV-2 infection remain unknown. In this paper, from the perspective of omnigenic, we analyze the properties of the neighborhood perturbed by SARS-CoV-2 in the human interactome and disclose the peripheral and core regions of virus-host network (VHN). We find that the virus-host proteins (VHPs) form a significantly connected VHN, among which highly perturbed proteins aggregate into an observable core region. The non-core region of VHN forms a large scale but relatively low perturbed periphery. We further validate that the periphery is non-negligible and conducive to identifying comorbidities and detecting drug repurposing candidates for COVID-19. We particularly put forward a flower model for COVID-19, SARS and H1N1 based on their peripheral regions, and the flower model shows more correlations between COVID-19 and other two similar diseases in common functional pathways and candidate drugs. Overall, our periphery-core pattern can not only offer insights into interconnectivity of SARS-CoV-2 VHPs but also facilitate the research on therapeutic drugs.

COVID 19 and liver: An A-Z literature review

The coronavirus pandemic has changed the priorities of the whole medical society. During the clinical course of COVID-19, it has been observed that hepatic injury occurs in a significant proportion of patients, particularly in those with severe or critical illness. In this literature review, we summarize the most recent studies, which covered the pathophysiology of COVID-19 induced liver injury including; hepatic pathological findings, therapy related liver damage, and the effects of the viral infection on pre-existing liver diseasesin context of the most recent recommendations. Conclusions: This review sheds light on the impact of COVID-19 infection on the liver, as well as the prognostic effect of liver laboratory markers on disease outcome. Temporal variations in liver parameters during disease course as well as different patterns of derangement are depicted. More intensive surveillance and individualized therapeutic approaches should be tailored for immunocompromised patients with advanced liver disease, hepatocellular carcinoma, and liver transplant patients. Despite the limited studies on COVID-19 infected patients with preexisting liver disease, this comprehensive overview provides a perspective on the management of liver disease during COVID-19.

Incidence, pattern and severity of abnormal liver blood tests among hospitalised patients with SARS-COV2 (COVID-19) in South Wales

INTRODUCTION

SARS-CoV-2 (COVID-19) is a novel coronavirus that emerged in Wuhan, China in late 2019 and since become a global pandemic. As such, its clinical behaviour is a subject of much interest. Initial reports suggested a significant proportion of patients have abnormal liver blood tests. Gwent has experienced one of the highest incidences of COVID-19 infection in the UK, which itself has among the highest COVID-19 impacts worldwide.

METHOD

We set out to report the incidence, clinical pattern and severity of liver blood test abnormalities in hospitalised patients with confirmed COVID-19 in our institution over a 3-week period. Data on clinical outcomes such as admission to intensive therapy unit (ITU), hospital discharge and mortality were recorded.

RESULTS

318 hospitalised COVID-19 positive had liver blood tests available for analysis. Ninety-seven patients (31%) had one or more abnormal liver blood tests and were abnormal admission in 64%. Liver tests were predominantly cholestatic (72%) in contrast to other studies to date. Male gender and abnormal liver blood tests were associated with ITU admission.

CONCLUSIONS

Almost one-third of admissions with COVID-19 have abnormal LBTs which are typically mild and are associated with male gender. Importantly, we have identified that cholestatic patterns dominate but were not clearly associated with ITU admission or death.