Hepatitis B virus induces expression of cholesterol metabolism-related genes via TLR2 in HepG2 cells

Prevalence of Non-Alcoholic Fatty Liver Disease and Its Impact on Fibrosis Risk in Inactive Chronic Hepatitis B Patients: Insights from a Cross-Sectional Study

Background: Chronic hepatitis B (CHB) and non-alcoholic fatty liver disease (NAFLD) are significant causes of chronic liver disease, potentially leading to liver cirrhosis and hepatocellular carcinoma. Moreover, the coexistence of CHB and NAFLD is increasingly common, although the relationship between NAFLD and inactive CHB infection remains poorly understood. Objectives: This study aimed to investigate the prevalence of NAFLD among patients with inactive CHB, identify risk factors for NAFLD, and determine predictors of significant fibrosis in these patients. Methods: This single-center cross-sectional study targeted patients with inactive CHB at Sultan Qaboos University Hospital from January 2010 to November 2021. Results: A total of 425 patients with inactive CHB were identified, of which 53.1% were male and 62.6% were aged 40-60 years. The prevalence of NAFLD was 47.8%. Various independent factors were associated with NAFLD, including type 2 diabetes mellitus, elevated low-density lipoprotein levels, high hemoglobin levels, low platelet counts, and normal alpha-fetoprotein levels. Significant associations were noted between NAFLD and significant fibrosis, with 10.5% of CHB patients with NAFLD exhibiting significant fibrosis compared to 1.4% of those without NAFLD. Other significant parameters included male gender, increased age, high alanine transaminase levels, elevated hemoglobin, and decreased platelet levels. Conclusions: The high prevalence of NAFLD in patients with inactive CHB and its associations with increased fibrosis and cirrhosis risk underscore the need for comprehensive management strategies for these patients.

Hepatic macrophage niche: a bridge between HBV-mediated metabolic changes with intrahepatic inflammation

Hepatitis B Virus (HBV) is a stealthy and insidious pathogen capable of inducing chronic necro-inflammatory liver disease and hepatocellular carcinoma (HCC), resulting in over one million deaths worldwide per year. The traditional understanding of Chronic Hepatitis B (CHB) progression has focused on the complex interplay among ongoing virus replication, aberrant immune responses, and liver pathogenesis. However, the dynamic progression and crucial factors involved in the transition from HBV infection to immune activation and intrahepatic inflammation remain elusive. Recent insights have illuminated HBV's exploitation of the sodium taurocholate co-transporting polypeptide (NTCP) and manipulation of the cholesterol transport system shared between macrophages and hepatocytes for viral entry. These discoveries deepen our understanding of HBV as a virus that hijacks hepatocyte metabolism. Moreover, hepatic niche macrophages exhibit significant phenotypic and functional diversity, zonal characteristics, and play essential roles, either in maintaining liver homeostasis or contributing to the pathogenesis of chronic liver diseases. Therefore, we underscore recent revelations concerning the importance of hepatic niche macrophages in the context of viral hepatitis. This review particularly emphasizes the significant role of HBV-induced metabolic changes in hepatic macrophages as a key factor in the transition from viral infection to immune activation, ultimately culminating in liver inflammation. These metabolic alterations in hepatic macrophages offer promising targets for therapeutic interventions and serve as valuable early warning indicators, shedding light on the disease progression.

[Role of cellular metabolism in the control of chronic viral hepatitis]

Hepatitis viruses modify the cellular metabolism of hepatocytes by interacting with specific enzymes such as glucokinase. The metabolic changes induced by viruses can have a direct impact on the innate antiviral response. The complex interactions between viral components, innate immunity, and hepatocyte metabolism explain why chronic hepatitis infections lead to liver inflammation, progressing to cirrhosis, fibrosis, and hepatocellular carcinoma. Metabolic regulators could be used in innovative therapies to deprive viruses of key metabolites and induce an antiviral defense.

Oncogenic viruses and host lipid metabolism: a new perspective

As noncellular organisms, viruses do not have their own metabolism and rely on the metabolism of host cells to provide energy and metabolic substances for their life cycles. Increasing evidence suggests that host cells infected with oncogenic viruses have dramatically altered metabolic requirements and that oncogenic viruses produce substances used for viral replication and virion production by altering host cell metabolism. We focused on the processes by which oncogenic viruses manipulate host lipid metabolism and the lipid metabolism disorders that occur in oncogenic virus-associated diseases. A deeper understanding of viral infections that cause changes in host lipid metabolism could help with the development of new antiviral agents as well as potential new therapeutic targets.

NAFLD and HBV interplay - related mechanisms underlying liver disease progression

Non-alcoholic fatty liver disease (NAFLD) and Hepatitis B virus infection (HBV) constitute common chronic liver diseases with worldwide distribution. NAFLD burden is expected to grow in the coming decade, especially in western countries, considering the increased incidence of diabetes and obesity. Despite the organized HBV vaccinations and use of anti-viral therapies globally, HBV infection remains endemic and challenging public health issue. As both NAFLD and HBV have been associated with the development of progressive fibrosis, cirrhosis and hepatocellular carcinoma (HCC), the co-occurrence of both diseases has gained great research and clinical interest. The causative relationship between NAFLD and HBV infection has not been elucidated so far. Dysregulated fatty acid metabolism and lipotoxicity in NAFLD disease seems to initiate activation of signaling pathways that enhance pro-inflammatory responses and disrupt hepatocyte cell homeostasis, promoting progression of NAFLD disease to NASH, fibrosis and HCC and can affect HBV replication and immune encountering of HBV virus, which may further have impact on liver disease progression. Chronic HBV infection is suggested to have an influence on metabolic changes, which could lead to NAFLD development and the HBV-induced inflammatory responses and molecular pathways may constitute an aggravating factor in hepatic steatosis development. The observed altered immune homeostasis in both HBV infection and NAFLD could be associated with progression to HCC development. Elucidation of the possible mechanisms beyond HBV chronic infection and NAFLD diseases, which could lead to advanced liver disease or increase the risk for severe complications, in the case of HBV-NAFLD co-existence is of high clinical significance in the context of designing effective therapeutic targets.

An Update on the Metabolic Landscape of Oncogenic Viruses

Viruses play an important role in cancer development as about 12% of cancer types are linked to viral infections. Viruses that induce cellular transformation are known as oncoviruses. Although the mechanisms of viral oncogenesis differ between viruses, all oncogenic viruses share the ability to establish persistent chronic infections with no obvious symptoms for years. During these prolonged infections, oncogenic viruses manipulate cell signaling pathways that control cell cycle progression, apoptosis, inflammation, and metabolism. Importantly, it seems that most oncoviruses depend on these changes for their persistence and amplification. Metabolic changes induced by oncoviruses share many common features with cancer metabolism. Indeed, viruses, like proliferating cancer cells, require increased biosynthetic precursors for virion production, need to balance cellular redox homeostasis, and need to ensure host cell survival in a given tissue microenvironment. Thus, like for cancer cells, viral replication and persistence of infected cells frequently depend on metabolic changes. Here, we draw parallels between metabolic changes observed in cancers or induced by oncoviruses, with a focus on pathways involved in the regulation of glucose, lipid, and amino acids. We describe whether and how oncoviruses depend on metabolic changes, with the perspective of targeting them for antiviral and onco-therapeutic approaches in the context of viral infections.

What role for cellular metabolism in the control of hepatitis viruses?

Hepatitis B, C and D viruses (HBV, HCV, HDV, respectively) specifically infect human hepatocytes and often establish chronic viral infections of the liver, thus escaping antiviral immunity for years. Like other viruses, hepatitis viruses rely on the cellular machinery to meet their energy and metabolite requirements for replication. Although this was initially considered passive parasitism, studies have shown that hepatitis viruses actively rewire cellular metabolism through molecular interactions with specific enzymes such as glucokinase, the first rate-limiting enzyme of glycolysis. As part of research efforts in the field of immunometabolism, it has also been shown that metabolic changes induced by viruses could have a direct impact on the innate antiviral response. Conversely, detection of viral components by innate immunity receptors not only triggers the activation of the antiviral defense but also induces in-depth metabolic reprogramming that is essential to support immunological functions. Altogether, these complex triangular interactions between viral components, innate immunity and hepatocyte metabolism may explain why chronic hepatitis infections progressively lead to liver inflammation and progression to cirrhosis, fibrosis and hepatocellular carcinoma (HCC). In this manuscript, we first present a global overview of known connections between the innate antiviral response and cellular metabolism. We then report known molecular mechanisms by which hepatitis viruses interfere with cellular metabolism in hepatocytes and discuss potential consequences on the innate immune response. Finally, we present evidence that drugs targeting hepatocyte metabolism could be used as an innovative strategy not only to deprive viruses of key metabolites, but also to restore the innate antiviral response that is necessary to clear infection.

Atorvastatin Rapidly Reduces Hepatitis B Viral Load in Combination with Tenofovir: A Prospective Clinical Trial

Objective and Aim. Atorvastatin inhibits cholesterol synthesis which is critically important in the formation of the viral envelope and secretion. The efficacy and safety of giving atorvastatin (40 mg/day) as an adjunct to tenofovir in the treatment of hepatitis B (HBV) were assessed. Method. In this single-blind clinical trial, 40 patients with active chronic hepatitis B were randomly allocated to treatment or control groups. The treatment group received the standard treatment for chronic HBV (300 mg tenofovir twice a day) along with 40 mg/day atorvastatin for 12 months, while the control group received a placebo once daily in addition to the standard tenofovir regimen. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and HBV DNA copy numbers were measured at the beginning of the treatment and 1, 3, 6, 9, 12 months later. Results. One month after starting the treatment, the HBV copy number in the atorvastatin + tenofovir-treated group was significantly lower, by 200×, compared with the control group. After three months of the treatment, there was no detectable HBV DNA in 50% of the atorvastatin + tenofovir-treated group compared with 30% in the control group. The half-life of plasma viral load was 2.03 and 3.32 months in the atorvastatin + tenofovir-treated and control groups, respectively. No adverse events due to taking atorvastatin were observed. Conclusions. The combination of atorvastatin with tenofovir increased antiviral activity and led to a faster recovery from viral infection. Therefore, this modality can be recommended as a safe combination therapy for chronic hepatitis B patients.

Viral Hepatitis, Cholesterol Metabolism, and Cholesterol-Lowering Natural Compounds

Hepatitis is defined as inflammation of the liver; it can be acute or chronic. In chronic cases, the prolonged inflammation gradually damages the liver, resulting in liver fibrosis, cirrhosis, and sometimes liver failure or cancer. Hepatitis is often caused by viral infections. The most common causes of viral hepatitis are the five hepatitis viruses—hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV), and hepatitis E virus (HEV). While HAV and HEV rarely (or do not) cause chronic hepatitis, a considerable proportion of acute hepatitis cases caused by HBV (sometimes co-infected with HDV) and HCV infections become chronic. Thus, many medical researchers have focused on the treatment of HBV and HCV. It has been documented that host lipid metabolism, particularly cholesterol metabolism, is required for the hepatitis viral infection and life cycle. Thus, manipulating host cholesterol metabolism-related genes and proteins is a strategy used in fighting the viral infections. Efforts have been made to evaluate the efficacy of cholesterol-lowering drugs, particularly 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, in the treatment of hepatitis viral infections; promising results have been obtained. This review provides information on the relationships between hepatitis viruses and host cholesterol metabolism/homeostasis, as well as the discovery/development of cholesterol-lowering natural phytochemicals that could potentially be applied in the treatment of viral hepatitis.

TLR2, as a Pathogen Recognition Receptor, Plays Critical Roles in Hepatitis B Outcome

The immune system of active and inactive chronic hepatitis B, as prolonged forms of hepatitis B, is unable to eradicate hepatitis B virus (HBV) from the infected hepatocytes completely. Toll-like receptors (TLRs) play key roles in the viral recognition and promotion of appropriate immune responses. The molecules also participate in the alteration of the target cell functions and transformation. TLR2 is the unique molecule that makes either homodimer or heterodimer with TLR1 and 6 and shows variable roles against viral infections. Therefore, it has been hypothesized that TLR2 may participate in both immune response against HBV and induction of the virus-related hepatic complications. The studies confirm the hypothesis and revealed that TLR2 is not only one of the main molecules altering the course of HBV infection, but also plays key roles in induction of hepatocellular carcinoma (HCC) and liver cirrhosis. However, recent studies demonstrated that the molecule can fight against HCC and liver cirrhosis. Collectively, it appears that nutrition habits, TLR2 gene polymorphisms, gut microbiome, HBV antigens, and activation of other receptors may play key roles in the determination of TLR2 functions.

Porcine reproductive and respiratory syndrome virus nsp4 positively regulates cellular cholesterol to inhibit type I interferon production

Cellular cholesterol plays an important role in the life cycles of enveloped viruses. Previous studies by our group and other groups have demonstrated that the depletion of cellular cholesterol by methyl-β-cyclodextrin (MβCD) reduces the proliferation of porcine reproductive and respiratory syndrome virus (PRRSV), a porcine Arterivirus that has been devastating the swine industry worldwide for over two decades. However, how PRRSV infection regulates cholesterol synthesis is not fully understood. In this study, we showed that PRRSV infection upregulated the activity of protein phosphatase 2 (PP2A), which subsequently activated 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), the rate-limiting enzyme in the cholesterol synthesis pathway, to increase the levels of cellular cholesterol. By screening the PRRSV-encoded proteins, we showed that nsp4 dominated the upregulation of cellular cholesterol, independently of the 3C-like protease activity of nsp4. A mutation analysis showed that domain I (amino acids 1–80) of PRRSV nsp4 interacted with PR65 alpha (PR65α), the structural subunit, and PP2Ac, the catalytic subunit, of PP2A. Importantly, domain I of nsp4 inhibited Sendai virus-induced interferon β production, and this inhibitory effect was eliminated by Lovastatin, an HMGCR inhibitor, indicating that the upregulation of cellular cholesterol by nsp4 is a strategy used by PRRSV to suppress the antiviral innate immunity of its host. Collectively, we here demonstrated the mechanism by which PRRSV regulates cellular cholesterol synthesis and reported a novel strategy by which PRRSV evades its host's antiviral innate immune response.

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PRRSV nsp4 up-regulates cellular cholesterol via the PP2A-HMGCR pathway.

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Nsp4 domain I (amino acids 1–80) interacts with A and C subunits of PP2A.

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Nsp4 domain I inhibits IFN-I production by upregulating cellular cholesterol.

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The HMGCR inhibitor Lovastatin inhibits PRRSV proliferation.

Effects of dyslipidemia on E antigen seroconversion of patients with chronic hepatitis B treated by nucleoside (acid) analogs

BACKGROUND

The prevalence of dyslipidemia in China is increasing annually. Current studies suggest that dyslipidemia affects the antiviral efficacy of hepatitis C virus (HCV) therapies, while recent studies suggest that serum lipids influence the response rates of chronic hepatitis B (CHB) patients receiving PEGylated interferon-alpha (Peg IFN-α) treatment. However, the role of dyslipidemia in the efficacy of nucleoside (acid) analogues (NAs) in CHB patients remains unclear.

METHODS

From January 2010 to December 2013, data from 179 treatment-naive patients with CHB who were hepatitis B e antigen (HBeAg)-positive and had visited the first affiliated hospital of Wenzhou Medical University were assessed. Of these patients, 68 were assigned to the dyslipidemia group (diagnosed with CHB complicated with dyslipidemia) and 111 to the normolipidemic group. The following 3 treatment strategies were performed for all CHB patients over a 5-year period: lamivudine (LAM) plus adefovir dipivoxil (ADV) combination therapy, telbivudine (LdT) monotherapy, and entecavir (ETV) monotherapy. Serum assessments, blood biochemistry, HBV serological markers, HBV DNA before treatment and HBeAg serological conversion and virological responses at different timepoints after treatment were compared between the two groups. Measurement data were compared by τ tests and enumeration data by χ2 tests. Correlation analysis was performed using binary logistic regression analysis.

RESULTS

The rates of HBeAg seroconversion in the dyslipidemia group at years 1, 2, 3, and 4 were 10.3, 13.2, 17.6, and 22.1%, respectively, which were not significantly lower than those of the normolipidemic group (11.7, 16.2, 18.0 and 33.3%; χ2 = 0.085, 0.293, 0.004, and 2.601, respectively; Ρ > 0.05). However, the rates of HBeAg seroconversion in the dyslipidemia group were significantly lower than those in the normolipidemic group at year 5 (27.9% vs. 43.2%, χ2 = 4.216, Ρ < 0.05). Univariate logistic regression analysis revealed significant differences in group, gender, PTA, ALT, AST, CR, and LDL-C between groups with and without seroconversion. Multivariate regression analysis demonstrated that dyslipidemia (OR = 1.993, Ρ = 0.038) and male gender (OR = 2.317, Ρ = 0.029) were risk factors associated with HBeAg seroconversion.

CONCLUSIONS

During antiviral therapy, dyslipidemia affects HBeAg seroconversion in CHB patients treated with NAs, but does not affect the virological response.

Autophagy Drives Galectin-1 Secretion From Tumor-Associated Macrophages Facilitating Hepatocellular Carcinoma Progression

Galectin-1 (Gal-1) is a secretory lectin with pro-tumor activities and is associated strongly with hepatocellular carcinoma (HCC) development. Although Gal-1 is a well-known soluble pro-tumor factor in the tumor microenvironment (TME), the secretion mode of Gal-1 is not clearly defined. On the other hand, in addition to cancer cells, Gal-1 is widely expressed in tumor stromal cells, including tumor-associated macrophages (TAMs). TAMs are a significant component of stromal cells in TME; however, their contributions in producing Gal-1 to TME are still not explored. Here we reveal that TAMs can actively secrete Gal-1 in response to stimuli of HCC cells. Gal-1 produced by TAMs leads to an increase of the systemic level of Gal-1 and HCC tumor growth in mice. Mechanistically, TLR2-dependent secretory autophagy is found to be responsible for Gal-1 secretion from TAMs. Gal-1 acts as a cargo of autophagosomes to fuse with multivesicular bodies via Rab11 and VAMP7-mediated vesicle trafficking before being secreted. This autophagy-regulated Gal-1 secretion in TAMs correlates to poor overall survival and progression-free survival rates of HCC patients. Our findings uncover the secretion mode of Gal-1 via secretory autophagy and highlight the pathological role of TAM-produced Gal-1 in HCC progression.

Prevalence and Incidence of Non-alcohol Fatty Liver Disease in Chronic Hepatitis B Population in Southeast China: A Community-Based Study

Background: To investigate the prevalence and incidence of non-alcohol fatty liver disease (NAFLD) in a community-based chronic hepatitis B (CHB) population from Southeast China and evaluate the association between NAFLD and metabolic factors, viral factors, and underlying chronic diseases.

Methods: CHB patients were recruited in 2012 and followed up from 2017 to 2019 in Zhejiang, China. NAFLD prevalence of the last visit and NAFLD incidence were calculated. Potential risk factors, including metabolic and viral factors, were also evaluated using Logistic or Cox regression models.

Results: NAFLD prevalence of the last visit in 2019 was estimated at 26.76%. Waist circumference, body mass index (BMI), triglyceride (TG), low-density lipoprotein (LDL), and diabetes mellitus (DM) were found as associated factors. In subgroups analysis, HBV infection types were also identified as a risk factor in the non-diabetic population. HBeAg-negative hepatitis and immunotolerant had lower NAFLD prevalence than past CHB infection. NAFLD incidence was estimated at 22.63/1,000 person-years after 1,634.74 person-years of follow-up. Waist circumference, TG, LDL, and alkaline phosphatase (ALP) were identified as associated factors.

Conclusion: The NAFLD prevalence and incidence in our study were slightly lower than previous reports from East Asia. Health education and healthy living habits were extremely important in reducing the NAFLD burden. Metabolic factors, history of DM, and viral factors were associated with NAFLD in CHB patients.

Liver Lipids of Patients with Hepatitis B and C and Associated Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) still remains a difficult to cure malignancy. In recent years, the focus has shifted to lipid metabolism for the treatment of HCC. Very little is known about hepatitis B virus (HBV) and C virus (HCV)-related hepatic lipid disturbances in non-malignant and cancer tissues. The present study showed that triacylglycerol and cholesterol concentrations were similar in tumor adjacent HBV and HCV liver, and were not induced in the HCC tissues. Higher levels of free cholesterol, polyunsaturated phospholipids and diacylglycerol species were noted in non-tumorous HBV compared to HCV liver. Moreover, polyunsaturated phospholipids and diacylglycerols, and ceramides declined in tumors of HBV infected patients. All of these lipids remained unchanged in HCV-related HCC. In HCV tumors, polyunsaturated phosphatidylinositol levels were even induced. There were no associations of these lipid classes in non-tumor tissues with hepatic inflammation and fibrosis scores. Moreover, these lipids did not correlate with tumor grade or T-stage in HCC tissues. Lipid reprogramming of the three analysed HBV/HCV related tumors mostly resembled HBV-HCC. Indeed, lipid composition of non-tumorous HCV tissue, HCV tumors, HBV tumors and HBV/HCV tumors was highly similar. The tumor suppressor protein p53 regulates lipid metabolism. The p53 and p53S392 protein levels were induced in the tumors of HBV, HCV and double infected patients, and this was significant in HBV infection. Negative correlation of tumor p53 protein with free cholesterol indicates a role of p53 in cholesterol metabolism. In summary, the current study suggests that therapeutic strategies to target lipid metabolism in chronic viral hepatitis and associated cancers have to consider disease etiology.

Analysis and Classification of Hepatitis Infections Using Raman Spectroscopy and Multiscale Convolutional Neural Networks

Hepatitis infections represent a major health concern worldwide. Numerous computer-aided approaches have been devised for the early detection of hepatitis. In this study, we propose a method for the analysis and classification of cases of hepatitis-B virus ( HBV), hepatitis-C virus (HCV), and healthy subjects using Raman spectroscopy and a multiscale convolutional neural network (MSCNN). In particular, serum samples of HBV-infected patients (435 cases), HCV-infected patients (374 cases), and healthy persons (499 cases) are analyzed via Raman spectroscopy. The differences between Raman peaks in the measured serum spectra indicate specific biomolecular differences among the three classes. The dimensionality of the spectral data is reduced through principal component analysis. Subsequently, features are extracted, and then feature normalization is applied. Next, the extracted features are used to train different classifiers, namely MSCNN, a single-scale convolutional neural network, and other traditional classifiers. Among these classifiers, the MSCNN model achieved the best outcomes with a precision of 98.89%, sensitivity of 97.44%, specificity of 94.54%, and accuracy of 94.92%. Overall, the results demonstrate that Raman spectral analysis and MSCNN can be effectively utilized for rapid screening of hepatitis B and C cases.

Transaminase Elevations during Treatment of Chronic Hepatitis B Infection: Safety Considerations and Role in Achieving Functional Cure

While current therapies for chronic HBV infection work well to control viremia and stop the progression of liver disease, the preferred outcome of therapy is the restoration of immune control of HBV infection, allowing therapy to be removed while maintaining effective suppression of infection and reversal of liver damage. This “functional cure” of chronic HBV infection is characterized by the absence of detectable viremia (HBV DNA) and antigenemia (HBsAg) and normal liver function and is the goal of new therapies in development. Functional cure requires removal of the ability of infected cells in the liver to produce the hepatitis B surface antigen. The increased observation of transaminase elevations with new therapies makes understanding the safety and therapeutic impact of these flares an increasingly important issue. This review examines the factors driving the appearance of transaminase elevations during therapy of chronic HBV infection and the interplay of these factors in assessing the safety and beneficial nature of these flares.

Multifaceted Interaction Between Hepatitis B Virus Infection and Lipid Metabolism in Hepatocytes: A Potential Target of Antiviral Therapy for Chronic Hepatitis B

Hepatitis B virus (HBV) is considered a “metabolic virus” and affects many hepatic metabolic pathways. However, how HBV affects lipid metabolism in hepatocytes remains uncertain yet. Accumulating clinical studies suggested that compared to non-HBV-infected controls, chronic HBV infection was associated with lower levels of serum total cholesterol and triglycerides and a lower prevalence of hepatic steatosis. In patients with chronic HBV infection, high ALT level, high body mass index, male gender, or old age was found to be positively correlated with hepatic steatosis. Furthermore, mechanisms of how HBV infection affected hepatic lipid metabolism had also been explored in a number of studies based on cell lines and mouse models. These results demonstrated that HBV replication or expression induced extensive and diverse changes in hepatic lipid metabolism, by not only activating expression of some critical lipogenesis and cholesterolgenesis-related proteins but also upregulating fatty acid oxidation and bile acid synthesis. Moreover, increasing studies found some potential targets to inhibit HBV replication or expression by decreasing or enhancing certain lipid metabolism-related proteins or metabolites. Therefore, in this article, we comprehensively reviewed these publications and revealed the connections between clinical observations and experimental findings to better understand the interaction between hepatic lipid metabolism and HBV infection. However, the available data are far from conclusive, and there is still a long way to go before clarifying the complex interaction between HBV infection and hepatic lipid metabolism.

Association of serum total cholesterol with pegylated interferon-α treatment in HBeAg-positive chronic hepatitis B patients

BACKGROUND

Recent studies suggest that serum lipids are associated with pegylated interferon-alpha (PEG-IFN-α) treatment response in chronic hepatitis C patients. However, the role of serum lipids in influencing the outcome of HBV treatment is not well understood. This study aims to investigate the association of serum lipids with the response to interferon-alpha treatment for chronic hepatitis B (CHB) patients.

METHODS

We dynamically measured 11 clinical serum lipid parameters of 119 hepatitis B e antigen (HBeAg)-positive CHB patients, including 53 patients who achieved sustained response (SR) and 66 patients who achieved non-response (NR) induced by PEG-IFN-α treatment for 48 weeks.

RESULTS

The dynamic analysis showed that the baseline serum total cholesterol (TCHO) level was higher in the NR group than that in the SR group (P=0.004). Moreover, the correlation analysis demonstrated a significant positive correlation between TCHO and hepatitis B surface antigen (HBsAg) at baseline (P=0.009). In addition, CHB patients with high baseline TCHO levels exhibited higher HBV DNA, HBsAg, HBeAg and hepatitis B e antibody (HBeAb) levels during early treatment periods (weeks 0, 4, 12 and 24) than those with the low TCHO levels. Furthermore, the logistic regression analysis identified that baseline serum TCHO was a risk factor for NR achievement (OR=4.94; P=0.047).

CONCLUSIONS

Our results indicated that serum TCHO was associated with PEG-IFN-α therapeutic response in HBeAg-positive CHB patients which suggested that serum TCHO could be useful as an auxiliary clinical factor to predict poor efficacy of PEG-IFN-α therapy.

Rapid screening of hepatitis B using Raman spectroscopy and long short-term memory neural network

This study presents a rapid method to screen hepatitis B patients using serum Raman spectroscopy combined with long short-term memory neural network (LSTM). The serum samples taken from 435 hepatitis B patients and 699 non-hepatitis B people were measured in this experiment. Specific biomolecular changes in three groups of serum samples could be seen in the tentative assignment of Raman peaks. First, principal component analysis (PCA) was used for extracting key features of spectral data, which reduces the dimension of the multidimensional spectrum. Then, LSTM is used to train the spectral data. Finally, the full connection layer completes the classification of HBV. The diagnostic accuracy of the first LSTM model is 97.32%, and the value of AUC is 0.995. The results from the study demonstrate that the combination of serum Raman spectroscopy technique and LSTM provides an effective technical approach to the screening of hepatitis B.

Chronic hepatitis B and non-alcoholic fatty liver disease: Conspirators or competitors?

Despite the widespread use of vaccines and antiviral drugs, approximately 350-400 million patients with chronic hepatitis B (CHB) remain worldwide, who carry high risk of cirrhosis and liver carcinoma. Moreover, owing to improvements in global living standards and lifestyle changes, non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease. Coexistence of NAFLD and CHB is commonly observed, especially in Asian CHB populations; however, little is known regarding the relationship between these two diseases as comorbidities. In this review, we summarize recent advances in clinical and basic researches related to the underlying mutual interactions, as well as potential animal models to facilitate further investigation.

Anti-ApoA-1 IgGs in Familial Hypercholesterolemia Display Paradoxical Associations with Lipid Profile and Promote Foam Cell Formation

AIMS

Anti-Apolipoprotein A-1 autoantibodies (anti-ApoA-1 IgG) promote atherogenesis via innate immune receptors, and may impair cellular cholesterol homeostasis (CH). We explored the presence of anti-ApoA-1 IgG in children (5-15 years old) with or without familial hypercholesterolemia (FH), analyzing their association with lipid profiles, and studied their in vitro effects on foam cell formation, gene regulation, and their functional impact on cholesterol passive diffusion (PD).

METHODS

Anti-ApoA-1 IgG and lipid profiles were measured on 29 FH and 25 healthy children. The impact of anti-ApoA-1 IgG on key CH regulators (SREBP2, HMGCR, LDL-R, ABCA1, and miR-33a) and foam cell formation detected by Oil Red O staining were assessed using human monocyte-derived macrophages. PD experiments were performed using a validated THP-1 macrophage model.

RESULTS

Prevalence of high anti-ApoA-1 IgG levels (seropositivity) was about 38% in both study groups. FH children seropositive for anti-ApoA-1 IgG had significant lower total cholesterol LDL and miR-33a levels than those who were seronegative. On macrophages, anti-ApoA-1 IgG induced foam cell formation in a toll-like receptor (TLR) 2/4-dependent manner, accompanied by NF-kB- and AP1-dependent increases of SREBP-2, LDL-R, and HMGCR. Despite increased ABCA1 and decreased mature miR-33a expression, the increased ACAT activity decreased membrane free cholesterol, functionally culminating to PD inhibition.

CONCLUSIONS

Anti-ApoA-1 IgG seropositivity is frequent in children, unrelated to FH, and paradoxically associated with a favorable lipid profile. In vitro, anti-ApoA-1 IgG induced foam cell formation through a complex interplay between innate immune receptors and key cholesterol homeostasis regulators, functionally impairing the PD cholesterol efflux capacity of macrophages.

The Effects of Hepatic Steatosis on the Natural History of HBV Infection

Fatty liver prevalence is increasing and becoming a global health burden. Chronic hepatitis B infection (CHB) is one of the most common chronic viral infections. Steatosis in CHB patients increases risk of cirrhosis and hepatocellular carcinoma. Data from studies on the interaction between CHB and nonalcoholic fatty liver disease are not conclusive. Liver biopsy is the gold standard for diagnosis of fatty liver; however, noninvasive diagnostic tests have been developed to diagnose and predict fibrosis in CHB/NAFLD. Treatment guidelines are not clear.

Intracellular hepatitis B virus increases hepatic cholesterol deposition in alcoholic fatty liver via hepatitis B core protein

Hepatitis B virus (HBV) infection is a prevalent infectious disease with serious outcomes like chronic and acute hepatitis, cirrhosis, and hepatocellular carcinoma. However, the metabolic alteration by HBV is rarely taken into consideration. With the high prevalence of alcohol consumption and chronic HBV infection, their overlap is assumed to be an increasing latent hazard; although the extent has not been calculated. Moreover, the impact of chronic alcohol consumption combined with HBV on cholesterol metabolism is unknown. Six-week-old male FVB/Ncrl mice were hydrodynamically injected with a pGEM-4Z-1.3HBV vector and then fed an ethanol diet for 6 weeks. Serum biomarkers and liver histology, liver cholesterol levels, and cholesterol metabolism-related molecules were measured. In vitro assays with HBx, hepatitis B surface (HBs), or hepatitis B core (HBc) protein expression in HepG2 cells costimulated with ethanol were conducted to assess the cholesterol metabolism. HBV expression synergistically increased cholesterol deposition in the setting of alcoholic fatty liver. The increase of intrahepatic cholesterol was due to metabolic alteration in cholesterol metabolism, including increased cholesterol synthesis, decreased cholesterol degradation, and impaired cholesterol uptake. Overexpression of HBV component HBc, but not HBs or HBx, selectively promoted the hepatocellular cholesterol level.

Impact of hepatitis B virus infection on hepatic metabolic signaling pathway

A growing body of epidemiologic research has demonstrated that metabolic derangement exists in patients with hepatitis B virus (HBV) infection, indicating that there are clinical associations between HBV infection and host metabolism. In order to understand the complex interplay between HBV and hepatic metabolism in greater depth, we systematically reviewed these alterations in different metabolic signaling pathways due to HBV infection. HBV infection interfered with most aspects of hepatic metabolic responses, including glucose, lipid, nucleic acid, bile acid and vitamin metabolism. Glucose and lipid metabolism is a particular focus due to the significant promotion of gluconeogenesis, glucose aerobic oxidation, the pentose phosphate pathway, fatty acid synthesis or oxidation, phospholipid and cholesterol biosynthesis affected by HBV. These altered metabolic pathways are involved in the pathological process of not only hepatitis B, but also metabolic disorders, increasing the occurrence of complications, such as hepatocellular carcinoma and liver steatosis. Thus, a clearer understanding of the hepatic metabolic pathways affected by HBV and its pathogenesis is necessary to develop more novel therapeutic strategies targeting viral eradication.

Hepatitis B e antigen-positive and high levels of alanine aminotransferase are associated with prevalence of metabolic syndrome in chronic HBV patients

OBJECTIVE

The interactions between hepatitis B virus (HBV) infection and metabolic syndrome (MS) have not been elucidated. This study was aimed to investigate the relationship between metabolic profile and HBV infection.

METHODS

A retrospective cross-sectional study including patients infected by HBV (HBV group, n=121) and healthy volunteers (control group, n=263) was conducted, serum HBV viral load and markers, serum alanine aminotransferase (ALT) levels and MS were analyzed. Factors associated with prevalence of MS were explored with multivariate adjusted logistic regression analyses.

RESULTS

The prevalence of MS was 9.9% in HBV infected patients and 19.4% in controls (p=0.011). Factors associated with the prevalence of MS were (odds ratio, 95% confidence interval, p value): hepatitis B e antigen (HBeAg) positive (0.368, 0.107-0.653, 0.008) and high levels of ALT (0.183, 0.120-0.268, <0.001) in HBV patients. But clinical and virological factors (including age, HBV DNA level, male gender, BMI, and fatty liver) were not found to be associated with prevalence of MS in HBV patients who were HBeAg positive with high levels of ALT.

CONCLUSION

These findings suggest that HBeAg positive and high levels of ALT are independently associated with lower prevalence of MS in HBV patients. But HBV DNA may not have impact on the lipid metabolism. HBV-related immune reactions may play a certain role in the mechanism of MS.

Clinical and laboratory characteristics associated with dyslipidemia and liver steatosis in chronic HBV carriers

INTRODUCTION

Chronic hepatitis B virus (HBV) infection and liver steatosis (LS) are the most common causes of chronic liver disease, and their coexistence is frequently observed in clinical practice. Although metabolic syndrome is the main cause of LS, it has not been associated with HBV infection. The aims of this study were to describe the lipid profile and prevalence of LS among HBV carriers and to identify the characteristics associated with LS in this group.

METHODS

This retrospective cross-sectional study included hepatitis B surface antigen (HBsAg)-positive patients evaluated during 2011 and 2012.

RESULTS

Of the 83 patients included, the mean age was 46.4±12.5 years, 53% were men, and 9.1% were hepatitis B e antigen (HBeAg) -positive. These patients exhibited the following lipid profile: total cholesterol = 175.4±38.8mg/dL, low-density lipoprotein (LDL) = 113.0±32.7mg/dL, and triglycerides = 91.1±45.2mg/dL. Their fasting glucose was 95.3±14.5g/dL, and fasting insulin was 6.1±5.9µIU/mL. Liver steatosis was observed on abdominal ultrasound in 11.3% of individuals. Factors associated with the presence of LS included higher levels of total cholesterol, prothrombin activity, fasting insulin, and body mass index (BMI) as well as lower levels of aspartate aminotransferase (AST).

CONCLUSIONS

These findings suggest that LS in patients with chronic HBV appears to be a consequence of metabolic alterations and insulin action rather than of viral factors.

Can Toll-Like Receptor (TLR) 2 be considered as a new target for immunotherapy against hepatitis B infection?

The current literature describes pivotal mechanisms in which hepatitis B virus (HBV) induces liver diseases including inflammation, cirrhosis and hepatocellular carcinoma (HCC). It appears that differences in genetic and immunological parameters between patients and controls may be responsible for inducing the prolonged forms of the infection. Previous studies demonstrated that Toll-Like Receptors (TLRs) play key roles in viral recognition and inducing appropriate immune responses. Therefore, TLRs can be considered as key sensors for HBV recognition and subsequent induction of immune responses against this virus. It has also been shown that the TLR2 detects several microbial PAMPs either in its homodimer form or in a heterodimer with TLR1 or TLR6 and subsequently activates NF-κB in a MYD88 dependent manner. Therefore, defective TLR2 expression may result in impaired immune responses against HBV which is reported in long-term forms of hepatitis B. This review presents the recent data regarding the status and important roles played by TLR2 in HBV recognition and induction or suppression of immune responses against HBV as well as its roles in the pathogenesis of cirrhosis and HCC in prolonged hepatitis B forms.

Role of innate immunity in the development of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common form of liver cancer worldwide. It is caused by a variety of risk factors, most common ones being infection with hepatitis viruses, alcohol, and obesity. HCC often develops in the background of underlying cirrhosis, and even though a number of interventional treatment methods are currently in use, recurrence is fairly common among patients who have had a resection. Therefore, whole liver transplantation remains the most practical treatment option for HCC. Due to the growing incidence of HCC, intense research efforts are being made to understand cellular and molecular mechanisms of the disease so that novel therapeutic strategies can be developed to combat liver cancer. In recent years, it has become clear that innate immunity plays a critical role in the development of a number of liver diseases, including HCC. In particular, the activation of Toll-like receptor signaling results in the generation of immune responses that often results in the production of pro-inflammatory cytokines and chemokines, and could cause acute inflammation in the liver. In this review, the current knowledge on the role of innate immune responses in the development and progression of HCC is examined, and emerging therapeutic strategies based on molecular mechanisms of HCC are discussed.