miR-122-induced down-regulation of HO-1 negatively affects miR-122-mediated suppression of HBV

miR-3188 inhibits hepatitis B virus transcription by targeting Bcl-2

Transcription of the covalently closed circular DNA (cccDNA) of hepatitis B virus (HBV) is subject to dual regulation by host factors and viral proteins. MicroRNAs (miRNAs) can regulate the expression of target genes at the post-transcriptional level. Systematic investigation of miRNA expression in HBV infection and the interaction between HBV and miRNAs may deepen our understanding of the transcription mechanisms of HBV cccDNA, thereby providing opportunities for intervention. miRNA sequencing and real-time quantitative PCR (qRT-PCR) were used to analyze miRNA expression after HBV infection of cultured cells. Clinical samples were analyzed for miRNAs and HBV transcription-related indicators, using qRT-PCR, enzyme-linked immunoassay (ELISA), and Western blot. miRNA mimics or inhibitors were used to study their effects on the HBV life cycle. The target genes of miR-3188 and their roles in HBV cccDNA transcription were also identified. The expression of 10 miRNAs, including miR-3188, which was significantly decreased after HBV infection, was measured in clinical samples from patients with chronic HBV infection. Overexpression of miR-3188 inhibited HBV transcription, whereas inhibition of miR-3188 expression promoted HBV transcription. Further investigation confirmed that miR-3188 inhibited HBV transcription by targeting Bcl-2. miR-3188 is a key miRNA that regulates HBV transcription by targeting the host protein Bcl-2. This observation provides insights into the regulation of cccDNA transcription and suggests new targets for anti-HBV treatment.

MicroRNAs participate in the regulation of apoptosis and oxidative stress-related gene expression in rabbits infected with Lagovirus europaeus GI.1 and GI.2 genotypes

MicroRNAs (miRs) are a group of small, 17-25 nucleotide, non-coding RNA that regulate gene expression at the post-transcriptional level. To date, little is known about the molecular signatures of regulatory interactions between miRs and apoptosis and oxidative stress in viral diseases. Lagovirus europaeus is a virus that causes severe disease in rabbits (Oryctolagus cuniculus) called Rabbit Hemorrhagic Disease (RHD) and belongs to the Caliciviridae family, Lagovirus genus. Within Lagovirus europaeus associated with RHD, two genotypes (GI.1 and GI.2) have been distinguished, and the GI.1 genotype includes four variants (GI.1a, GI.1b, GI.1c, and GI.1d). The study aimed to assess the expression of miRs and their target genes involved in apoptosis and oxidative stress, as well as their potential impact on the pathways during Lagovirus europaeus-two genotypes (GI.1 and GI.2) infection of different virulences in four tissues (liver, lung, kidneys, and spleen). The expression of miRs and target genes related to apoptosis and oxidative stress was determined using quantitative real-time PCR (qPCR). In this study, we evaluated the expression of miR-21 (PTEN, PDCD4), miR-16b (Bcl-2, CXCL10), miR-34a (p53, SIRT1), and miRs-related to oxidative stress-miR-122 (Bach1) and miR-132 (Nfr-2). We also examined the biomarkers of both processes (Bax, Bax/Bcl-2 ratio, Caspase-3, PARP) and HO-I as biomarkers of oxidative stress. Our report is the first to present the regulatory effects of miRs on apoptosis and oxidative stress genes in rabbit infection with Lagovirus europaeus-two genotypes (GI.1 and GI.2) in four tissues (liver, lungs, kidneys, and spleen). The regulatory effect of miRs indicates that, on the one hand, miRs can intensify apoptosis (miR-16b, miR-34a) in the examined organs in response to a viral stimulus and, on the other hand, inhibit (miR-21), which in both cases may be a determinant of the pathogenesis of RHD and tissue damage. Biomarkers of the Bax and Bax/Bcl-2 ratio promote more intense apoptosis after infection with the Lagovirus europaeus GI.2 genotype. Our findings demonstrate that miR-122 and miR-132 regulate oxidative stress in the pathogenesis of RHD, which is associated with tissue damage. The HO-1 biomarker in the course of rabbit hemorrhagic disease indicates oxidative tissue damage. Our findings show that miR-21, miR-16b, and miR-34a regulate three apoptosis pathways. Meanwhile, miR-122 and miR-132 are involved in two oxidative stress pathways.

Emerging Therapies for Chronic Hepatitis B and the Potential for a Functional Cure

Worldwide, an estimated 296 million people are living with chronic hepatitis B virus (HBV) infection, with a significant risk of morbidity and mortality. Current therapy with pegylated interferon (Peg-IFN) and indefinite or finite therapy with nucleoside/nucleotide analogues (Nucs) are effective in HBV suppression, hepatitis resolution, and prevention of disease progression. However, few achieve hepatitis B surface antigen (HBsAg) loss (functional cure), and relapse often occurs after the end of therapy (EOT) because these agents have no direct effect on durable template: covalently closed circular DNA (cccDNA) and integrated HBV DNA. Hepatitis B surface antigen loss rate increases slightly by adding or switching to Peg-IFN in Nuc-treated patients and this loss rate greatly increases up to 39% in 5 years with finite Nuc therapy with currently available Nuc(s). For this, great effort has been made to develop novel direct-acting antivirals (DAAs) and immunomodulators. Among the DAAs, entry inhibitors and capsid assembly modulators have little effect on reducing HBsAg levels; small interfering RNA, antisense oligonucleotides, and nucleic acid polymers in combination with Peg-IFN and Nuc may reduce HBsAg levels significantly, even a rate of HBsAg loss sustained for > 24 weeks after EOT up to 40%. Novel immunomodulators, including T-cell receptor agonists, check-point inhibitors, therapeutic vaccines, and monoclonal antibodies may restore HBV-specific T-cell response but not sustained HBsAg loss. The safety issues and the durability of HBsAg loss warrant further investigation. Combining agents of different classes has the potential to enhance HBsAg loss. Compounds directly targeting cccDNA would be more effective but are still in the early stage of development. More effort is required to achieve this goal.

Human Heme Oxygenase-1 Promoter Activity Is Mediated by Z-DNA Formation

In recent years, it has been shown that Z-DNA formation in DNA plays functionally significant roles in nucleic acid metabolism, such as gene expression, chromosome recombination, and epigenetic regulation. The reason for the identification of these effects is mainly due to the advancement of Z-DNA detection methods in target genome regions in living cells.The heme oxygenase-1 (HO-1) gene encodes an enzyme that degrades an essential prosthetic heme, and environmental stimuli, including oxidative stress, lead to robust induction of the HO-1 gene. Many DNA elements and transcription factors are involved in the induction of the HO-1 gene, and Z-DNA formation in the thymine-guanine (TG) repetitive sequence in the human HO-1 gene promoter region is required for maximum gene induction.Here, we describe a detailed protocol for Z-DNA detection in the human HO-1 gene promoter region based on chromatin immunoprecipitation with quantitative PCR. We also provide some control experiments to consider in routine lab procedures.

Fatty hepatocytes-derived exosomal miR-122 reduces immune function and antioxidant defence in Ctenopharyngodon idella kidney (CIK) cells

Exosomes are important for intercellular "cross talk", but the role of exosomes in communication between hepatocytes and C. idella kidney (CIK) cells remains unknown. In this study, we detected the changes in factors related to immune and oxidative stress to investigate the molecular mechanism by which fatty hepatocyte-derived exosomes (OA-Exos) reduced immunity and induced oxidative stress in CIK cells. After incubation of CIK cells by OA-Exos for 24 h, tumor necrosis factor-α (TNF-α), nuclear factor-κB (NF-κB) and interleukin-1β (IL-1β) were significantly upregulated in the OA-Exos group (P < 0.05), and Mn superoxide dismutase (Mn-SOD) and heme oxygenase-1 (HO-1) were significantly downregulated (P < 0.05). Surprisingly, miR-122 expression was also significantly elevated after OA-Exos incubation. We further identified the expression of miR-122 and found that it was notably increased in OA-Exos compared to hepatocyte-derived exosomes (Exos). Then we transfected CIK cells with miR-122 mimic, consistently, the expression of inflammatory cytokines was also significantly elevated (P < 0.05), and the expression of glutathione peroxidase (GPx), HO-1, and Mn-SOD were dramatically decreased (P < 0.05). Furthermore, HO-1 was improved to be a direct target of miR-122, and transfection with HO-1 siRNA indicated that changes in inflammatory cytokines and genes related to oxidative stress were consistent with the above results of CIK cells incubated with OA-Exos and miR-122 mimic. We concluded that OA-Exos may, through the miR-122/HO-1 pathway, reduce immune function and antioxidant defence in CIK cells.

Modes of action and diagnostic value of miRNAs in sepsis

Sepsis is a clinical syndrome defined as a dysregulated host response to infection resulting in life-threatening organ dysfunction. Sepsis is a major public health concern associated with one in five deaths worldwide. Sepsis is characterized by unbalanced inflammation and profound and sustained immunosuppression, increasing patient susceptibility to secondary infections and mortality. microRNAs (miRNAs) play a central role in the control of many biological processes, and deregulation of their expression has been linked to the development of oncological, cardiovascular, neurodegenerative and metabolic diseases. In this review, we discuss the role of miRNAs in sepsis pathophysiology. Overall, miRNAs are seen as promising biomarkers, and it has been proposed to develop miRNA-based therapies for sepsis. Yet, the picture is not so straightforward because of the versatile and dynamic features of miRNAs. Clearly, more research is needed to clarify the expression and role of miRNAs in sepsis, and to promote the use of miRNAs for sepsis management.

ADAR1 Inhibits HBV DNA Replication via Regulating miR-122-5p in Palmitic Acid Treated HepG2.2.15 Cells

BACKGROUND AND AIMS

Changes in living standards and diet structure, non-alcoholic fatty liver disease (NAFLD) is prevalent globally, including in Asia, where chronic hepatitis B (CHB) is endemic. As such, cooccurrence of NAFLD with CHB is common in Asia. However, the pathogenesis underlying the onset of fatty liver in CHB prognosis has not been fully elucidated. Therefore, we aimed to investigate the effects and mechanisms of lipotoxicity on hepatitis B virus (HBV) DNA replication.

METHODS

The expression of adenosine deaminase acting on RNA-1 (ADAR1) and miR-122 was evaluated in liver tissues from patients with CHB concurrent NAFLD. Palmitic acid-treated HepG2.2.15 cells were used as the cell model. The effect of lipotoxicity on HBV DNA replication was evaluated in vitro by transfecting the ADAR1 overexpression or knockdown lentiviral vector into HepG2.2.15 cells, respectively. qRT-PCR, western blotting and immunofluorescence were performed to determine ADAR1 expression.

RESULTS

The expression of ADAR1 in the liver tissues of CHB patients with concurrent NAFLD was significantly down-regulated compared with that in CHB patients. Enforced expression of ADAR1 inhibited the HBV DNA replication, whereas ADAR1 knockdown resulted in increased HBV DNA expression in palmitic acid - treated HepG2.2.15 cells. Additionally, ADAR1 inhibited the HBV DNA replication by upregulating miR-122, which is most abundant in the liver and mainly inhibits HBV DNA replication.

CONCLUSIONS

ADAR1 may act as a suppressor of HBV replication in palmitic acid -treated HepG2.2.15 cells by increasing miR-122 levels. Thus, ADAR1 may serve as a potential biomarker and therapeutic target for CHB with concurrent NAFLD.

Suppression of Interferon-α Treatment Response by Host Negative Factors in Hepatitis B Virus Infection

Chronic hepatitis B virus (CHB) infection remains a major global public health issue for which there is still lacking effective curative treatment. Interferon-α (IFN-α) and its pegylated form have been approved as an anti-HBV drug with the advantage of antiviral activity and host immunity against HBV infection enhancement, however, IFN-α treatment failure in CHB patients is a challenging obstacle with 70% of CHB patients respond poorly to exogenous IFN-α treatment. The IFN-α treatment response is negatively regulated by both viral and host factors, and the role of viral factors has been extensively illustrated, while much less attention has been paid to host negative factors. Here, we summarized evidence of host negative regulators and parameters involved in IFN-α therapy failure, review the mechanisms responsible for these effects, and discuss the possible improvement of IFN-based therapy and the rationale of combining the inhibitors of negative regulators in achieving an HBV cure.

Azoxystrobin increases the infection of spring viraemia of carp virus in fish

Azoxystrobin (AZ) has entered aquatic ecosystems and produced serious damages to fish associated with potentially increasing the susceptibility to pathogens. This study characterized the defense abilities of fish by exposed to AZ on challenging with the infection of spring viraemia of carp virus (SVCV). The results showed that SVCV replication increased significantly in EPC cells and zebrafish that were exposed to up to 50 μg/L of AZ at 3, 5, 7, and 14 d. Intracellular biochemical assays indicated that AZ at 5 and 50 μg/L inhibited the activation of Nrf2-ARE pathway including a decrease in Nrf2 expression, Nrf2 phosphorylation, HO-1 content, and three antioxidant activities. While no significant difference in ERK1/2 and JNK MAPKs in zebrafish was observed, P38 phosphorylation was significantly decreased at 7 and 14 d, and the changes in MAPKs were more evident in EPC cells previously exposed to AZ at 7 d. These results revealed that AZ initially induced low phosphorylation of MAPKs, triggering the attenuation of Nrf2 phosphorylation to weaken Nrf2 translocation into the nucleus in a longer exposure period (more than 5 d). The data in the cells and fish also showed that antioxidant activities were decreased to some extent at 5-7 d for the cells and 7-14 d for the fish. Furthermore, interferon-related factors were decreased in AZ-exposed zebrafish, explaining the reason that fish can't resist the virus infection. Overall, the present study provided a new adverse threat of AZ by amplifying the viral outbreak to endanger ecological safety in aquatic environment.

Emodin resists to Cyprinid herpesvirus 3 replication via the pathways of Nrf2/Keap1-ARE and NF-κB in the ornamental koi carp (Cyprinus carpio haematopterus)

Cyprinid herpesvirus 3 (CyHV-3) causes high mortality in carp. Emodin has been shown of the effects of antioxidant, anti-inflammatory and antiviral. In present study, we investigated the preventive effects and mechanism of emodin on CyHV-3 infection. The ornamental koi carp (Cyprinus carpio haematopterus) were intraperitoneally injected with emodin (10 mg/kg, 20 mg/kg, or 40 mg/kg). 72 h later, an intraperitoneal injection of CyHV-3 was administered, and collected the samples one week later to detect the antioxidant parameters, antioxidant genes, inflammatory genes and to perform histopathology assays. The results showed that emodin significantly suppressed CyHV-3 replication (P < 0.05), improved the koi survival rate and slowed the damage caused by CyHV-3. Emodin treatment increased the antioxidant activity and decreased the lipid peroxidation level of the koi. Compared to the CyHV-3 group, emodin treatment resulted in the same antioxidant parameters after CyHV-3 infection. Emodin treatment activated the Nuclear factorery throid 2-related factor 2/Kelch-like ECH-associated protein 1-antioxidatant response element (Nrf2/Keap1-ARE) pathway and upregulated the expression of heme oxygenase 1 (HO-1), superoxide dismutase (SOD), and catalase (CAT) in the hepatopancreas after CyHV-3 infection. Emodin activated the nuclear factor kappa-B (NF-κB) pathway and decreased the expression of interleukin-6 (IL-6), interleukin-8 (IL-8), and tumour necrosis factor-α (TNF-α) in the koi induced by CyHV-3. In conclusion, emodin treatment can suppress CyHV-3 replication and reduce the mortality of koi caused by CyHV-3. Emodin improves antioxidant function, relieves oxidative stress and inflammation cytokines via Nrf2/Keap1-ARE and NF-κB pathways, and protects against the adverse effects induced by CyHV-3.

Diagnosis and Therapeutic Management of Liver Fibrosis by MicroRNA

Remarkable progress has been made in the treatment and control of hepatitis B and C viral infections. However, fundamental treatments for diseases in which liver fibrosis is a key factor, such as cirrhosis, alcoholic/nonalcoholic steatohepatitis, autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis, are still under development and remain an unmet medical need. To solve this problem, it is essential to elucidate the pathogenesis of liver fibrosis in detail from a molecular and cellular perspective and to develop targeted therapeutic agents based on this information. Recently, microRNAs (miRNAs), functional RNAs of 22 nucleotides, have been shown to be involved in the pathogenesis of liver fibrosis. In addition, extracellular vesicles called “exosomes” have been attracting attention, and research is being conducted to establish noninvasive and extremely sensitive biomarkers using miRNAs in exosomes. In this review, we summarize miRNAs directly involved in liver fibrosis, miRNAs associated with diseases leading to liver fibrosis, and miRNAs related to complications of cirrhosis. We will also discuss the efficacy of each miRNA as a biomarker of liver fibrosis and pathology, and its potential application as a therapeutic agent.

Circulating MicroRNA-21 and MicroRNA-122 as Prognostic Biomarkers in Hepatocellular Carcinoma Patients Treated with Transarterial Chemoembolization

BACKGROUND

MicroRNAs (miRNAs) have been proposed as biomarkers in hepatocellular carcinoma (HCC). We aim at evaluating miR-21 and miR-122 in HCC patients treated with drug-eluting beads transarterial chemoembolization (DEB-TACE) as prognostic biomarkers and investigating their correlation with hypoxia inducible factor-1α (HIF-1α) serum levels.

METHODS

In this retrospective study, 12 healthy subjects, 28 cirrhotics, and 54 HCC patients (tested before and four weeks after DEB-TACE) were included. Whole blood miR-21 and miR-122 levels were measured by quantitative real time (qRT)-PCR, while serum HIF-1α was assessed by an enzyme-linked immunosorbent assay (ELISA) test.

RESULTS

The highest level of miR-21 was found in cirrhotics, while HCC patients had the highest level of miR-122 (which was even higher in "viral" HCC, p = 0.006). miR-21 ratio (after/before DEB-TACE) and miR-122 below their respective cut-offs identified patients with longer progression-free survival (p = 0.0002 and p = 0.02, respectively). The combined assessment of alpha-fetoprotein and miR-21 ratio, both independent prognostic predictors, identified early progressors among patients with complete or partial radiological response. miR-21 levels positively correlated with HIF-1α before (p = 0.045) and after DEB-TACE (p = 0.035).

CONCLUSIONS

miR-21 ratio and miR-122 are useful prognostic markers after DEB-TACE. miR-21 correlates with HIF-1α and probably has a role in modulating angiogenesis in HCC.

Strategies to Inhibit Hepatitis B Virus at the Transcript Level

Approximately 240 million people are chronically infected with hepatitis B virus (HBV), despite four decades of effective HBV vaccination. During chronic infection, HBV forms two distinct templates responsible for viral transcription: (1) episomal covalently closed circular (ccc)DNA and (2) host genome-integrated viral templates. Multiple ubiquitous and liver-specific transcription factors are recruited onto these templates and modulate viral gene transcription. This review details the latest developments in antivirals that inhibit HBV gene transcription or destabilize viral transcripts. Notably, nuclear receptor agonists exhibit potent inhibition of viral gene transcription from cccDNA. Small molecule inhibitors repress HBV X protein-mediated transcription from cccDNA, while small interfering RNAs and single-stranded oligonucleotides result in transcript degradation from both cccDNA and integrated templates. These antivirals mediate their effects by reducing viral transcripts abundance, some leading to a loss of surface antigen expression, and they can potentially be added to the arsenal of drugs with demonstrable anti-HBV activity. Thus, these candidates deserve special attention for future repurposing or further development as anti-HBV therapeutics.

Silencing hepatitis B virus covalently closed circular DNA: The potential of an epigenetic therapy approach

Global prophylactic vaccination programmes have helped to curb new hepatitis B virus (HBV) infections. However, it is estimated that nearly 300 million people are chronically infected and have a high risk of developing hepatocellular carcinoma. As such, HBV remains a serious health priority and the development of novel curative therapeutics is urgently needed. Chronic HBV infection has been attributed to the persistence of the covalently closed circular DNA (cccDNA) which establishes itself as a minichromosome in the nucleus of hepatocytes. As the viral transcription intermediate, the cccDNA is responsible for producing new virions and perpetuating infection. HBV is dependent on various host factors for cccDNA formation and the minichromosome is amenable to epigenetic modifications. Two HBV proteins, X (HBx) and core (HBc) promote viral replication by modulating the cccDNA epigenome and regulating host cell responses. This includes viral and host gene expression, chromatin remodeling, DNA methylation, the antiviral immune response, apoptosis, and ubiquitination. Elimination of the cccDNA minichromosome would result in a sterilizing cure; however, this may be difficult to achieve. Epigenetic therapies could permanently silence the cccDNA minichromosome and promote a functional cure. This review explores the cccDNA epigenome, how host and viral factors influence transcription, and the recent epigenetic therapies and epigenome engineering approaches that have been described.

Analysis of Serum MicroRNA-122 Expression at Different Stages of Chronic Hepatitis B Virus Infection

Objective

To investigate the expression of microRNA-122 (miR-122) in the progression of chronic hepatitis B virus- (HBV-) infected liver diseases, thus determining the role of serum miR-122 as a marker of HBV-caused liver injury.

Methods

Sera were collected from patients with different stages of HBV infection (n = 63) and healthy volunteers (n = 11). And the serum miR-122 levels were detected using RT-qPCR. Moreover, an analysis was applied for identifying the specific correlation of the miR-122 level with HBV DNA, HBeAg, and ALT levels. After liver biopsy, Ishak scoring was utilized for evaluation of the fibrosis stage and the histological activity index (HAI).

Results

We confirmed, in the serum, increased miR-122 expression in HBV-infected patients and its highest expression in chronic HBV carriers, based on such comparison between the healthy controls and patients. The correlation analysis results were taken as confirmation of the positive relationship of miR-122 with HBV DNA (r = 0.354, P = 0.005) and ALT (r = 0.331, P = 0.009). But no correlation of this molecule with HBeAg levels was found (P = 0.187). In comparison with the HBeAg-negative patients, serum miR-122 expression showed an increase in the HBeAg-positive patients (P = 0.001). miR-122 expression, in addition, was of a significant correlation with HAI, but not with the liver fibrosis score.

Conclusion

The peak of the serum miR-122 expression normally occurs in the early stage of the progression from the HBV carrier phase to chronic hepatitis to cirrhosis. This molecule can be considered as a marker for evaluation of HBV-caused liver injury.

Inhibition of micro RNA miR-122-5p prevents lipopolysaccharide-induced myocardial injury by inhibiting oxidative stress, inflammation and apoptosis via targeting GIT1

Myocardial injury resulting from sepsis is the leading cause of death worldwide. Micro RNA miR-122-5p is involved in various physiological and pathological processes and is highly expressed in the heart of septic rats. However, its function in sepsis-caused myocardial injury remains elusive. Herein, a rat model of septic myocardial injury was established by intraperitoneal injection of lipopolysaccharide (LPS), and cardiomyocyte H9c2 was exposed to LPS to induce sepsis-related inflammatory injury in vitro. Inhibition of miR-122-5p suppressed LPS-triggered myocardial injury evidenced by decreased heart weight index (HWI), reduced inflammatory cell infiltration and cell rupture, and reduced cardiac marker enzymes cTnI and LDH. MiR-122-5p inhibition inhibited ROS production and enhanced the activities of antioxidant enzymes CAT, SOD and GSH-px in LPS-treated rats and H9c2 cells. MiR-122-5p inhibition reduced the production of pro-inflammatory cytokines TNF-α, IL-6 and IL-1β, and inhibited cell apoptosis along with decreased cleaved-caspase 3 induced by LPS. Moreover, increased GIT1 expression was found following miR-122-5p inhibition. We further verified GIT1 as a target of miR-122-5p, and silencing GIT1 partially reversed the benefits of miR-122-5p loss in LPS-injured H9c2 cells. The HO-1 and NQO-1 expression and Nrf-2 activation were enhanced by miR-122-5p inhibition, which was reversed by GIT1 depletion, indicating the involvement of Nrf-2/HO-1 signaling in regulating miR-122-5p/GIT1-mediated cardioprotection. Taken together, our data suggest that inhibition of miR-122-5p may mitigate sepsis-triggered myocardial injury through inhibiting inflammation, oxidative stress and apoptosis via targeting GIT1, which provides a possible therapeutic target for sepsis.

Potential of Sulforaphane as a Natural Immune System Enhancer: A Review

Brassicaceae are an outstanding source of bioactive compounds such as ascorbic acid, polyphenols, essential minerals, isothiocyanates and their precursors, glucosinolates (GSL). Recently, GSL gained great attention because of the health promoting properties of their hydrolysis products: isothiocyanates. Among them, sulforaphane (SFN) became the most attractive one owing to its remarkable health-promoting properties. SFN may prevent different types of cancer and has the ability to improve hypertensive states, to prevent type 2 diabetes–induced cardiomyopathy, and to protect against gastric ulcer. SFN may also help in schizophrenia treatment, and recently it was proposed that SFN has potential to help those who struggle with obesity. The mechanism underlying the health-promoting effect of SFN relates to its indirect action at cellular level by inducing antioxidant and Phase II detoxifying enzymes through the activation of transcription nuclear factor (erythroid-derived 2)-like (Nrf2). The effect of SFN on immune response is generating scientific interest, because of its bioavailability, which is much higher than other phytochemicals, and its capacity to induce Nrf2 target genes. Clinical trials suggest that sulforaphane produces favorable results in cases where pharmaceutical products fail. This article provides a revision about the relationship between sulforaphane and immune response in different diseases. Special attention is given to clinical trials related with immune system disorders.

MicroRNAs in the Pathogenesis of Hepatocellular Carcinoma: A Review

Simple Summary

Hepatocellular carcinoma (HCC) is one of the most frequently occurring cancers, and the prognosis for late-stage HCC remains poor. A better understanding of the pathogenesis of HCC is expected to improve outcomes. MicroRNAs (miRNAs) are small, noncoding, single-stranded RNAs that regulate the expression of various target genes, including those in cancer-associated genomic regions or fragile sites in various human cancers. We summarize the central roles of miRNAs in the pathogenesis of HCC and discuss their potential utility as valuable biomarkers and new therapeutic agents for HCC.

Abstract

Hepatocellular carcinoma (HCC) is the seventh most frequent cancer and the fourth leading cause of cancer mortality worldwide. Despite substantial advances in therapeutic strategies, the prognosis of late-stage HCC remains dismal because of the high recurrence rate. A better understanding of the etiology of HCC is therefore necessary to improve outcomes. MicroRNAs (miRNAs) are small, endogenous, noncoding, single-stranded RNAs that modulate the expression of their target genes at the posttranscriptional and translational levels. Aberrant expression of miRNAs has frequently been detected in cancer-associated genomic regions or fragile sites in various human cancers and has been observed in both HCC cells and tissues. The precise patterns of aberrant miRNA expression differ depending on disease etiology, including various causes of hepatocarcinogenesis, such as viral hepatitis, alcoholic liver disease, or nonalcoholic steatohepatitis. However, little is known about the underlying mechanisms and the association of miRNAs with the pathogenesis of HCC of various etiologies. In the present review, we summarize the key mechanisms of miRNAs in the pathogenesis of HCC and emphasize their potential utility as valuable diagnostic and prognostic biomarkers, as well as innovative therapeutic targets, in HCC diagnosis and treatment.

MicroRNAs Profiling in HIV, HCV, and HIV/HCV Co-Infected Patients

BACKGROUND

Human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections are important public health issues.

OBJECTIVE

This study aimed to assess the association between microRNAs expression leveland immunological and viral markers in HIV, HCV, and HIV/HCV co-infected patients.

METHODS

The expression level of miR-29, miR-149, miR-199, miR-let7, miR-223, miR-155, miR-122, and miR-150 was evaluated in 20 HIV, 20 HCV, 20 co-infected patients, and 20 healthy controls using real-time PCR assay. HIV and HCVviral loads were measuredby real-time PCR, and also, CD4+ T-lymphocyte count was measuredby the PIMA CD4 analyzer.

RESULTS

The miRNA expression pattern in each mentioned group showed significantly different expression profiles, but some miRNA species were shared between the groups. MiR-122 and miR-155 were upregulated, while miR-29 and miR-223 were downregulated in three patients groups compared to healthy controls. A significant positive correlation was observed between the expression of miR-122 and HIV/HCV loads. But, miR-29 and let-7 were negatively correlated with HIV load, and miR-149 and let-7 were negatively correlated with HCV load. Also, miR-155 was positively correlated with HCV load. MiR-122 and miR-199 were negative while others were positively correlated with CD4+ T cell count.

CONCLUSION

These miRNAs are probably involved in the clinical progression and pathogenesis of HIV and HCV infections. Therefore, determining and manipulating these miRNAs can lead to opening a new gate to control these important infections.

Potential Drug Targets Against Hepatitis B Virus Based on Both Virus and Host Factors

BACKGROUND

Hepatitis B is a very harmful and epidemic disease caused by hepatitis B virus (HBV). Although an effective anti-HBV vaccine is available, chronic infection poses still a huge health burden in the whole world. The present anti-HBV drugs including nucleoside analogues and interferonalpha have their limitations without exception. There is no effective drug and therapeutic method that can really and truly cure hepatitis B so far. The variability of HBV genome results in that a significant number of patients develop drug resistance during the long-term use of anti-HBV drugs. Hence, it is urgently needed to discover novel targets and develop new drugs against hepatitis B.

OBJECTIVE

The review aims to provide the theory support for designing of the anti-HBV innovative drugs by offering a summary of the current situation of antiviral potential targets.

RESULTS AND CONCLUSION

Since HBV is obligate intracellular parasite, and as such it depends on host cellular components and functions to replicate itself. The targeting both virus and host might be a novel therapeutic option for hepatitis B. Accordingly, we analyse the advances in the study of the potential drug targets for anti-HBV infection, focusing on targeting virus genome, on targeting host cellular functions and on targeting virus-host proteins interactions, respectively. Meanwhile, the immune targets against chronic hepatitis B are also emphasized. In short, the review provides a summary of antiviral therapeutic strategies to target virus factors, host factors and immune factors for future designing of the innovative drug against HBV infection.

Exosomal miRNAs in hepatitis B virus related liver disease: a new hope for biomarker

The World Health Organisation, in its 2019 progress report on HIV, viral hepatitis and STDs indicates that 257 million people are afflicted with chronic HBV infections, of which, 1 million patients lose their lives every year due to HBV related chronic liver diseases including serious complications such as liver cirrhosis and hepatocellular carcinoma. The course of HBV infection and associated liver injury depend on several host factors, genetic variability of the virus, and the host viral interplay. The challenge of medical science is the early diagnosis/identification of the potential for development of fatal complications like liver cirrhosis and HCC so that timely medical intervention can improve the chances of survival. Currently, neither the vaccination regime nor the diagnostic methods are completely effective as reflected in the high number of annual deaths. It is evident from numerous publications that microRNAs (miRNAs) are the critical regulators of gene expression and various cellular processes like proliferation, development, differentiation, apoptosis and tumorigenesis. Expressions of these diminutive RNAs are significantly affected in cancerous tissues as a result of numerous genomic and epigenetic modifications. Exosomes are membrane-derived vesicles (30–100 nm) secreted by normal as well as malignant cells, and are present in all body fluids. They are recognized as critical molecules in intercellular communication between cells through horizontal transfer of information via their cargo, which includes selective proteins, mRNAs and miRNAs. Exosomal miRNAs are transferred to recipient cells where they can regulate target gene expression. This provides an insight into the elementary biology of cancer progression and therefore the development of therapeutic approaches. This concise review outlines various on-going research on miRNA mediated regulation of HBV pathogenesis with special emphasis on association of exosomal miRNA in advanced stage liver disease like hepatocellular carcinoma. This review also discusses the possible use of exosomal miRNAs as biomarkers in the early detection of HCC and liver cirrhosis.

Detection of miR-122 by fluorescence real-time PCR in blood from patients with chronic hepatitis B and C infections

BACKGROUND

This study aims to determine whether relative miR-122 levels in peripheral blood are correlated with chronic hepatitis B (CHB) and chronic hepatitis C (CHC) virus infection and viral replication to determine whether miR-122 can be a new marker for liver injury.

METHODS

MicroRNA (miRNA) was extracted from the peripheral blood of 20 CHB patients, 20 CHC patients, and 20 healthy controls. The levels of miR-122 were determined using fluorescence real-time reverse transcription PCR. Then, the associations of miR-122 with CHB and CHC were analyzed, and its correlation with other markers of liver function and viral replication were determined.

RESULTS

The expression level of miR-122 in patients with CHB was significantly higher when compared to subjects in the control group (P = 0.007) or CHC patients (P = 0.005). Furthermore, the miR-122 level in patients with CHC was somewhat higher when compared to healthy controls (66% higher), but the difference was not statistically significant (P = 0.229). MiR-122 levels were significantly correlated with ALT (correlation coefficient [R] = 0.7, P < 0.001), AST (R = 0.71, P < 0.001), and HBV NA (R = 0.9, P < 0.001). The regression analysis indicated that the AUC of miR-122 levels in the diagnosis of CHB was 0.87, with a sensitivity of 0.8 and a specificity of 0.8.

CONCLUSION

MiR-122 can be used to distinguish healthy persons and patients with CHB infection with high sensitivity and specificity. These present findings presented that the complex and context-specific associations of miR-122 with liver diseases, suggesting that this may be a promising marker for liver injury.

Metalloprotoporphyrin Inhibition of HCV NS3-4A Protease: Structure-Activity Relationships

Background

Antiviral actions of tetrapyrroles have been described in a number of systems. Our goal was to evaluate antagonism of the HCV NS3-4A protease by a variety of common porphyrins and characterize structure-activity relationships that may be useful for future drug design of HCV and related Flaviviruses.

Methods

Using fluorometric assays, common metalloprotoporphyrins (MPP) all inhibited NS3-4A protease with IC₅₀ values in low micromolar ranges [CoPP (1.4 µM) < ZnPP = MnPP = SnPP < CuPP < FePP (6.5 µM) = protoporphyrin].

Results

Lineweaver-Burk plots confirmed that MPP: NS3 inhibition was basically competitive. All tested MPPs inhibited HCV genotype 1A, 1B, 2A and 3A recombinant proteases with the same fidelity suggesting wide antagonistic capabilities. However, when the MPPs were tested in cellular incubations with HCV replicons only Zn, Fe and free-base protoporphyrin showed comparable EC₅₀ and IC₅₀ values suggesting that there may be critical differences in MPP uptake and intracellular availability. Meso, deutero, and isohematoporphyrin derivatives, with or without metal substitution, all showed less anti-protease and antiviral activities as compared to protoporphyrins, suggesting that the planar, vinyl side chains are important for protease active site binding. MPPs were also active against three common protease mutants (T54A, A156T, and V36M) with equivalent or better IC₅₀ values as compared to wild type enzyme.

Conclusion

These findings document the versatility of MPPs as antiviral agents with an expanded sensitivity for HCV genotypes and resistance to some common viral mutations. The results also suggest that further study of MPP structure and function will be useful for the development of new antiviral agents.

The Regulatory Role of MicroRNA in Hepatitis-B Virus-Associated Hepatocellular Carcinoma (HBV-HCC) Pathogenesis

The incidence and mortality of hepatitis B virus (HBV)-associated hepatocellular carcinoma (HBV-HCC) is an intractable public health problem in developing countries that is compounded by limited early detection and therapeutic options. Despite the early promise of utilizing the regulatory role of miRNA in liver cancer, this field remains largely in the work-in-progress phase. This exploratory review paper adopts a broad focus in order to collate evidence of the regulatory role of miRNA in each stage of the HBV-HCC continuum. This includes the regulatory role of miRNA in early HBV infection, chronic inflammation, fibrosis/cirrhosis, and the onset of HCC. The paper specifically investigates HBV dysregulated miRNA that influence the expression of the host/HBV genome in HBV-HCC pathogenesis and fully acknowledges that this does not cover the full spectrum of dysregulated miRNA. The sheer number of dysregulated miRNA in each phase support a hypothesis that future therapeutic interventions will need to consider incorporating multiple miRNA panels.

MicroRNA-122 in patients with hepatitis B and hepatitis B virus-associated hepatocellular carcinoma

Hepatitis B virus (HBV) infection is known as a serious problem in the domain of public health and approximately 350 million people across the world are affected with this infectious disease. As well, microRNAs are recognized as a type of small non-coding RNAs that can be widely used as a diagnostic biomarker and prognosis method of special diseases. In this respect, microRNA-122 or miR-122 can play a significant role in the pathogenesis of several hepatic diseases. Given the importance of microRNA-122 in the liver as well as its pathology, this study focused on the potential functions of microRNA-122 in pathogenesis, diagnosis, and treatment of HBV infection. In this regard, the findings of previous studies had indicated that expression of microRNA-122 in patients with HBV infection could be significantly deregulated. The results of this study were consistent with the idea that diagnosis and treatment of this infectious disease using microRNA-122 could be an efficient method.

Circulating microRNAs as Potential Diagnostic and Prognostic Biomarkers in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer with high mortality, due to late diagnosis and limited treatment options. Blood miRNAs, which circulate in a highly stable, cell-free form, show promise as novel potential biomarkers for early detection of HCC. Whole miRNome profiling was performed to identify deregulated miRNAs between HCC and normal healthy (NH) volunteers. These deregulated miRNAs were validated in an independent cohort of HCC, NH and chronic Hepatitis B (CHB) volunteers and finally in a 3^rd cohort comprising NH, CHB, cirrhotic and HCC volunteers to evaluate miRNA changes during disease progression. The associations between circulating miRNAs and liver-damage markers, clinicopathological characteristics and survival outcomes were analysed to identify prognostic markers. Twelve miRNAs are differentially expressed between HCC and NH individuals in all three cohorts. Five upregulated miRNAs (miR-122-5p, miR-125b-5p, miR-885-5p, miR-100-5p and miR-148a-3p) in CHB, cirrhosis and HCC patients are potential biomarkers for CHB infection, while miR-34a-5p can be a biomarker for cirrhosis. Notably, four miRNAs (miR-1972, miR-193a-5p, miR-214-3p and miR-365a-3p) can distinguish HCC from other non-HCC individuals. Six miRNAs are potential prognostic markers for overall survival.

Inhibitory Effect on the Hepatitis B Cells through the Regulation of miR-122-MAP3K2 signal pathway

The aim of this study was to investigate the inhibitory effect of regulation of miR-122-MAP3K2 signal pathway on the hepatitis B cells. We detected the content of MAP3K2 from patients with HBV blood serum samples and analyzed the correlation between content of MAP3K2 and copies of HBV-DNA. Wound healing and Transwell assays were used to detect the function of cells from control group (wild type) and observer group (overexpresses miR-122). Secretion levels of HBsAg and MAP3K2 in the supernatant and level of MAP3K2 in cells were detected by ELISA and western blot, respectively. The results showed that there was a positive correlation between the copies of HBV-DNA and MAP3K2 in serum. In the assays involving detection of the number of HBV-DNA copies, the supernatant levels of HBsAg and MAP3K2, and the level of MAP3K2 in the cells, the rate of increase of these indicators significantly slowed as culture time. In conclusion, overexpression of miR-122 could inhibit the migration of hepatoblastoma cells; however, following transfection with miR-122, DNA synthesis and the secretion of HBsAg were inhibited. Overexpression of miR-122 can also downregulate MAP3K2. Consequently, we concluded that regulating the miR-122-MAP3K2 signaling pathway exerts an inhibitory effect in hepatitis B cells.

PMA-triggered PKCε activity enhances Nrf2-mediated antiviral response on fish rhabdovirus infection

Viral infection is often accompanied with alteration of intracellular redox state, especially an imbalance between reactive oxygen species (ROS) production and antioxidant cellular defenses. The previous studies showed that an antioxidant cellular defense system, the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), played an important role against spring viraemia of carp virus (SVCV) infection in fish. To further reveal the mediated mechanism that Nrf2 active state was affected by protein kinase C (PKC), here we evaluated SVCV replication in host cells by treated with a strong activator of PKC phorbol-12-myristate-13-acetate (PMA) and an inhibitor staurosporine. Our results showed that PMA significantly repressed SVCV replication and viral-induced apoptosis in Epithelioma papulosum cyprini (EPC) cell, suggesting that PKC may exhibit an anti-SVCV effect. Likewise, PMA resulted in a higher phosphorylation levels of PKCε rather than PKCα/β to participate in the activation of Nrf2, mainly involved in the activation of Nrf2 phosphorylation of Ser40 to favor Nrf2 translocation to nucleus. Furthermore, the data revealed that PMA up-regulated an antiviral response heme oxygenase-1 (HO1) gene expression that was confirmed as the key player against SVCV infection by HO1 specific siRNA. Overall, this study provided a new therapeutic target for the treatment of SVCV infection, and modulating PKC activity could be used for the prevention and treatment of SVCV.

microRNAs: Key players in virus-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is known as one of the major health problems worldwide. Pathological analysis indicated that a variety of risk factors including genetical (i.e., alteration of tumor suppressors and oncogenes) and environmental factors (i.e., viruses) are involved in beginning and development of HCC. The understanding of these risk factors could guide scientists and clinicians to design effective therapeutic options in HCC treatment. Various viruses such as hepatitis B virus (HBV) and hepatitis C virus (HCV) via targeting several cellular and molecular pathways involved in HCC pathogenesis. Among various cellular and molecular targets, microRNAs (miRNAs) have appeared as key players in HCC progression. miRNAs are short noncoding RNAs which could play important roles as oncogenes or tumor suppressors in several malignancies such as HCC. Deregulation of many miRNAs (i.e., miR-222, miR-25, miR-92a, miR-1, let-7f, and miR-21) could be associated with different stages of HCC. Besides miRNAs, exosomes are other particles which are involved in HCC pathogenesis via targeting different cargos, such as DNAs, RNAs, miRNAs, and proteins. In this review, we summarize the current knowledge of the role of miRNAs and exosomes as important players in HCC pathogenesis. Moreover, we highlighted HCV- and HBV-related miRNAs which led to HCC progression.

Antiviral effect of 7-(4-benzimidazole-butoxy)-coumarin on rhabdoviral clearance via Nrf2 activation regulated by PKCα/β phosphorylation

Coumarin forms an elite class of naturally occurring compounds that possess promising antiviral therapeutic perspectives. In the previous study, we designed and synthesized a coumarin derivative, 7-(4-benzimidazole-butoxy)-coumarin (BBC), to evaluate its antiviral activity on spring viraemia of carp virus (SVCV). In this study, our results show that BBC does not affect viral adhesion and delivery from endosomes to the cytosol, indicating BBC has no inhibitory activity in the early stage of viral infection. Further data are determined that BBC significantly declines SVCV-infected apoptosis and recovers caspase-3/8/9 activity. To reveal the pathway that affects Nrf2 translocation by BBC, we examine changes in protein kinase C (PKC) in EPC cells treated with BBC. We observe that BBC results in a higher phosphorylation of PKCα/β that is involved in the activation of erythroid 2-related factor 2 (Nrf2) phosphorylation to favor Nrf2 translocation to nucleus at 24 and 48 h. In addition, the results show that BBC also up-regulates both antiviral responses, heme oxygenase-1 (HO-1) expression and cellular IFN response. Overall, this mechanism of action provides a new therapeutic target for the treatment of SVCV infection, and these results suggest that treatment with BBC is effective in reducing SVCV infection and differently regulates SVCV-induced undesirable conditions.

Host functions used by hepatitis B virus to complete its life cycle: Implications for developing host-targeting agents to treat chronic hepatitis B

Similar to other mammalian viruses, the life cycle of hepatitis B virus (HBV) is heavily dependent upon and regulated by cellular (host) functions. These cellular functions can be generally placed in to two categories: (a) intrinsic host restriction factors and innate defenses, which must be evaded or repressed by the virus; and (b) gene products that provide functions necessary for the virus to complete its life cycle. Some of these functions may apply to all viruses, but some may be specific to HBV. In certain cases, the virus may depend upon the host function much more than does the host itself. Knowing which host functions regulate the different steps of a virus' life cycle, can lead to new antiviral targets and help in developing novel treatment strategies, in addition to improving a fundamental understanding of viral pathogenesis. Therefore, in this review we will discuss known host factors which influence key steps of HBV life cycle, and further elucidate therapeutic interventions targeting host-HBV interactions.

Micro-RNAs in hepatitis B virus-related chronic liver diseases and hepatocellular carcinoma

MicroRNAs (miRNAs) are small non-coding RNAs that modulate gene expression at the post-transcriptional level by affecting both the stability and translation of complementary mRNAs. Several studies have shown that miRNAs are important regulators in the conflicting efforts between the virus (to manipulate the host for its successful propagation) and the host (to inhibit the virus), culminating in either the elimination of the virus or its persistence. An increasing number of studies report a role of miRNAs in hepatitis B virus (HBV) replication and pathogenesis. In fact, HBV is able to modulate different host miRNAs, particularly through the transcriptional transactivator HBx protein and, conversely, different cellular miRNAs can regulate HBV gene expression and replication by a direct binding to HBV transcripts or indirectly targeting host factors. The present review will discuss the role of miRNAs in the pathogenesis of HBV-related diseases and their role as a biomarker in the management of patients with HBV-related disease and as therapeutic targets.

Roles of microRNAs in T cell immunity: Implications for strategy development against infectious diseases

T cell immunity plays a vital role in pathogen infections. MicroRNA (miRNAs) are small, single-stranded noncoding RNAs that regulate T cell immunity by targeting key transcriptional factors, signaling proteins, and cytokines associated with T cell activation, differentiation, and function. The dysregulation of miRNA expression in T cells may lead to specific immune responses and can provide new therapeutic opportunities against various infectious diseases. Here, we summarize recent studies that focus on the roles of miRNAs in T cell immunity and highlight miRNA functions in prevalent infectious diseases. Additionally, we also provide insights into the functions of extracellular vesicle miRNAs and attempt to delineate the mechanism of miRNA sorting into extracellular vesicles and their immunomodulatory functions. Moreover, methodologies and strategies for miRNA delivery against infectious diseases are summarized. Finally, potential strategies for miRNA-based therapies are proposed.

Long Non-coding RNAs: Regulators of Viral Infection and the Interferon Antiviral Response

Interferons (IFNs) are a family of cytokines providing a robust first line of host innate defense against pathogenic infection, and have now been part of the standard treatment for viral infection. However, IFN based therapy can best be described as modestly effective. Long non-coding RNAs (lncRNAs) are a novel class of non-protein-coding RNAs that are capable of regulating gene expression at different levels, including chromatin, transcription, post-transcription, and translation. Recently, lncRNAs are found to be deregulated upon viral infection or IFN treatment, and some of them can modulate viral infection in an IFN-dependent or -independent manner. Due to the crucial roles of lncRNAs in viral infection and the IFN antiviral response, the modulation of specific lncRNAs may be involved to increase the IFN antiviral response and improve the clinical result of IFN-based therapy. In this review, we summarize lncRNAs that are deregulated by viral infection, with special focus on the functions and underlying mechanisms of some essential lncRNAs, and discuss their roles in viral infection and the antiviral response of IFN.

Host heme oxygenase-1: Friend or foe in tackling pathogens?

Infectious diseases are a major challenge in management of human health worldwide. Recent literature suggests that host immune system could be modulated to ameliorate the pathogenesis of infectious disease. Heme oxygenase (HMOX1) is a key regulator of cellular signaling and it could be modulated using pharmacological reagents. HMOX1 is a cytoprotective enzyme that degrades heme to generate carbon monoxide (CO), biliverdin, and molecular iron. CO and biliverdin (or bilirubin derived from it) can restrict the growth of a few pathogens. Both of these also induce antioxidant pathways and anti-inflammatory pathways. On the other hand, molecular iron can induce proinflammatory pathway besides making the cellular environment oxidative in nature. Since microbial infections often induce oxidative stress in host cells/tissues, role of HMOX1 has been analyzed in the pathogenesis of number of infections. In this review, we have described the role of HMOX1 in pathogenesis of bacterial infections caused by Mycobacterium species, Salmonella and in microbial sepsis. We have also provided a succinct overview of the role of HMOX1 in parasitic infections such as malaria and leishmaniasis. In the end, we have also elaborated the role of HMOX1 in viral infections such as AIDS, hepatitis, dengue, and influenza. © 2018 IUBMB Life, 70(9):869-880, 2018.

Current concepts on immunopathogenesis of hepatitis B virus infection

Hepatitis B virus (HBV) infection is a leading cause of liver damage and hepatic inflammation. Upon infection, effective antiviral responses by CD8+ T cells, CD4+ T cells, Natural killer (NK) cells, and monocytes can lead to partial or complete eradication of the viral infection. To date, many studies have shown that the production of inhibitory cytokines such as Interleukin 10 (IL-10), Transforming growth factor beta (TGF-β), along with dysfunction of the dendritic cells (DCs), and the absence of efficient innate immune responses could lead to T cell exhaustion, development of persistent infection, and inability to eradicate the viral infection from liver. Understanding the immunopathogenesis of the virus could be useful in providing further insights toward novel strategies in the eradication of HBV infection.

Long Non-Coding RNAs in Hepatitis B Virus-Related Hepatocellular Carcinoma: Regulation, Functions, and Underlying Mechanisms

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of cancer death in the world. Hepatitis B virus (HBV) and its X gene-encoded protein (HBx) play important roles in the progression of HCC. Although long non-coding RNAs (lncRNAs) cannot encode proteins, growing evidence indicates that they play essential roles in HCC progression, and contribute to cell proliferation, invasion and metastasis, autophagy, and apoptosis by targeting a large number of pivotal protein-coding genes, miRNAs, and signaling pathways. In this review, we briefly outline recent findings of differentially expressed lncRNAs in HBV-related HCC, with particular focus on several key lncRNAs, and discuss their regulation by HBV/HBx, their functions, and their underlying molecular mechanisms in the progression of HCC.

Identification and characterization of interferon signaling-related microRNAs in occult hepatitis B virus infection

Background

Occult hepatitis B virus infection (OBI) is an important risk factor of liver cirrhosis and hepatocellular carcinoma. Type 1 interferon (IFN) signaling-related miRNAs were significantly associated with hepatitis B virus (HBV) infection. However, the characteristics of serum IFN signaling-related miRNAs in OBI remain unclear. Therefore, this study aimed to analyze the expression levels of serum IFN signaling-related miRNAs in OBI and to evaluate their potential values for OBI diagnosis.

Methods

Twenty serum samples for training test (10 healthy controls and 10 OBI patients) and 438 validation serum samples from healthy controls, asymptomatic HBsAg carriers (ASC), and chronic hepatitis B (CHB) and OBI patients were collected. Expression levels of 32 IFN signaling-related miRNAs were analyzed in training and validation sets of samples using RT-qPCR.

Results

Among 32 IFN signaling-related miRNAs, decreased miR-122 levels and increased miR-130a levels were detected in training OBI samples. Furthermore, the results from validation test showed that the mean serum miR-122 and miR-130a level was 2.28 ± 0.96 and 3.11 ± 0.93 in OBI subjects, respectively. Compared to the healthy controls, ASC and CHB patients, miR-122 levels were significantly downregulated, while miR-130a levels were significantly upregulated in OBI patients. ROC analysis indicated that miR-122 + miR-130a could differentiate OBI from healthy controls, ASC, and CHB (≥ 0.87 of AUC).

Conclusions

Our study suggested that decreased serum miR-122 level and increased miR-130a level were significantly associated with OBI. Moreover, a combination of miR-122 and miR-130a could be served as a potential marker for OBI diagnosis.

Electronic supplementary material

The online version of this article (10.1186/s13148-017-0404-9) contains supplementary material, which is available to authorized users.

WITHDRAWN: Epigenetics in Chronic Liver Disease

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Plasma MicroRNA Levels Are Associated With Hepatitis B e Antigen Status and Treatment Response in Chronic Hepatitis B Patients

Background

Hepatitis B virus (HBV) modulates microRNA (miRNA) expression to support viral replication. The aim of this study was to identify miRNAs associated with hepatitis B e antigen (HBeAg) status and response to antiviral therapy in patients with chronic hepatitis B (CHB) , and to assess if these miRNAs are actively secreted by hepatoma cells.

Methods

Plasma miRNA levels were measured by reverse-transcription quantitative polymerase chain reaction in healthy controls (n = 10) and pretreatment samples of an identification cohort (n = 24) and a confirmation cohort (n = 64) of CHB patients treated with peginterferon/nucleotide analogue combination therapy. Levels of HBV-associated miRNAs were measured in cells, extracellular vesicles, and hepatitis B surface antigen (HBsAg) particles of hepatoma cell lines.

Results

HBeAg-positive patients had higher plasma levels of miR-122-5p, miR-125b-5p, miR-192-5p, miR-193b-3p, and miR-194-5p compared to HBeAg-negative patients, and levels of these miRNAs were associated with HBV DNA and HBsAg levels. Pretreatment plasma levels of miR-301a-3p and miR-145-5p were higher in responders (combined response or HBsAg loss) compared to nonresponders. miR-192-5p, miR-193b-3p, and miR-194-5p were present in extracellular vesicles and HBsAg particles derived from hepatoma cells.

Conclusions

We identified miRNAs that are associated with HBeAg status, levels of HBV DNA and HBsAg, and treatment response in CHB patients. We demonstrated that several of these miRNAs are present in extracellular vesicles and HBsAg particles secreted by hepatoma cells.

Serum microRNA-122 and Wisteria floribunda agglutinin-positive Mac-2 binding protein are useful tools for liquid biopsy of the patients with hepatitis B virus and advanced liver fibrosis

Background

Noninvasive methods to accurately and conveniently evaluate liver fibrosis are desirable. MicroRNA (miR) is one of the candidates. MiRs are small RNAs consisting of 19–25 nucleotides that negatively regulate many target genes at transcriptional levels. Recently, many researchers have focused on circulating miRs in the blood stream as biomarkers. Hepatic miR-122 has been reported to have an association with viral replication and hepatic fibrosis in chronic hepatitis B virus (HBV) and hepatic C virus (HCV) infection.

Methods

We measured serum miR-122 levels in HBV- and HCV-infected patients confirmed with liver biopsy. We also investigated a novel liver fibrosis marker Wisteria floribunda agglutinin-positive Mac-2 binding protein [WFA(+)-M2BP]. We evaluated the diagnostic usefulness of these markers in hepatic fibrosis and inflammation of patients with chronic viral infection.

Results

The serum miR-122 levels of HBV-infected patients were higher than those of the control subjects. In HBV-infected patients, the serum miR-122 levels of patients with advanced liver fibrosis were significantly lower. Serum WFA(+)-M2BP was significantly higher dependent on both the staging of fibrosis and the grading of inflammatory activity in patients with both HBV and HCV infection. We also observed that higher serum WFA(+)-M2BP levels augmented the prediction of advanced liver fibrosis among HBV-infected patients with lower serum miR-122 levels.

Conclusions

A lower serum miR-122 level is a useful predictor of advanced liver fibrosis in HBV-infected patients. Serum WFA(+)-M2BP could predict liver fibrosis in both HBV and HCV infection. The combination of these markers may result in the more accurate evaluation of liver fibrosis in HBV infection.

Modulation of Antiviral Immunity by Heme Oxygenase-1

Heme oxygenase-1 (HO-1) is a stress-inducible, anti-inflammatory, and cytoprotective enzyme expressed in most cell types in the organism. Under several stress stimuli, HO-1 expression and activity is up-regulated to catalyze the rate-limiting enzymatic step of heme degradation into carbon monoxide, free iron, and biliverdin. Besides its effects on cell metabolism, HO-1 is also capable of modulating host innate and adaptive immune responses in response to sepsis, transplantation, and autoimmunity, and preventing oxidative damage associated with inflammation. In addition, recent studies have reported that HO-1 can exert a significant antiviral activity against a wide variety of viruses, including HIV, hepatitis C virus, hepatitis B virus, enterovirus 71, influenza virus, respiratory syncytial virus, dengue virus, and Ebola virus, among others. Herein, we address the current understanding of the functional significance of HO-1 against a variety of viruses and its potential as a therapeutic strategy to prevent and control viral infections. Furthermore, we review the most important features of the immunoregulatory functions for this enzyme.

MicroRNA-122 as a predictor of HBsAg seroclearance in hepatitis B and C dual infected patients treated with interferon and ribavirin

It has been demonstrated that microRNA-122 (miR-122) plays key roles in the modulation of hepatitis B virus (HBV) replication. This study examined the role of miR-122 in patients with hepatitis C virus (HCV)-HBV dual infection with active hepatitis C who received pegylated interferon-α and ribavirin dual therapy. We enrolled 121 patients with HCV-HBV dual infection after dual therapy. Stored serum was collected before treatment. RT-PCR was used to analyze miR-122. HBsAg seroclearance was noted in 37 (30.1%) cases during a median follow-up period of 5.4 years. miR-122 was significantly lower in HBsAg seroclearance patients than in non-HBsAg seroclearance patients (P < 0.014). Multivariate analysis showed that miR-122 was an independent factor of HBsAg seroclearance (OR: 0.30, 95% CI: 0.09–0.98, P = 0.046). miR-122 was significantly higher in patients who were qHBsAg > 100 IU/mL versus ≤100 IU/mL (P < 0.001). We concluded that in patients with HBV-HCV dual infection with active hepatitis C, miR-122 was associated with HBsAg seroclearance after therapy and qHBsAg level before therapy, indicating that miR-122 plays key roles in modulating HBV replication.

Heme oxygenase-1 retards hepatocellular carcinoma progression through the microRNA pathway

Heme metabolism system is involved in microRNA (miRNA) biogenesis. The complicated interplay between heme oxygenase-1 (HO-1) and miRNA has been observed in various tissues and diseases, including human malignancy. In the present study, our data showed that stable HO-1 overexpression in hepatocellular carcinoma (HCC) cells downregulated several oncomiRs. The most stably downregulated are miR-30d and miR-107. Iron, one of HO-1 catalytic products, was an important mediator in this regulation. Cell function analysis demonstrated that HO-1 inhibited the proliferation and metastasis of HepG2 cells, whereas miR-30d/miR-107 improved the proliferative and migratory ability of HepG2 cells. The beneficial effect of HO-1 in HCC inhibition could be reversed by upregulating miR-30d and miR-107. Akt and ERK pathways may be involved in the regulation of HO-1/miR-30d/miR-107 in HCC. These data indicate that HO-1 significantly suppresses HCC progression by regulating the miR-30d/miR-107 level, suggesting miR-30d/miR-107 regulation as a new molecular mechanism of HO-1 anticancer effect.

Roles of hepatocyte nuclear factors in hepatitis B virus infection

Approximately 350 million people are estimated to be persistently infected with hepatitis B virus (HBV) worldwide. HBV maintains persistent infection by employing covalently closed circular DNA (cccDNA), a template for all HBV RNAs. Chronic hepatitis B (CHB) patients are currently treated with nucleos(t)ide analogs such as lamivudine, adefovir, entecavir, and tenofovir. However, these treatments rarely cure CHB because they are unable to inhibit cccDNA transcription and inhibit only a late stage in the HBV life cycle (the reverse transcription step in the nucleocapsid). Therefore, an understanding of the factors regulating cccDNA transcription is required to stop this process. Among numerous factors, hepatocyte nuclear factors (HNFs) play the most important roles in cccDNA transcription, especially in the generation of viral genomic RNA, a template for HBV replication. Therefore, proper control of HNF function could lead to the inhibition of HBV replication. In this review, we summarize and discuss the current understanding of the roles of HNFs in the HBV life cycle and the upstream factors that regulate HNFs. This knowledge will enable the identification of new therapeutic targets to cure CHB.

Hepatitis B virus molecular biology and pathogenesis

As obligate intracellular parasites, viruses need a host cell to provide a milieu favorable to viral replication. Consequently, viruses often adopt mechanisms to subvert host cellular signaling processes. While beneficial for the viral replication cycle, virus-induced deregulation of host cellular signaling processes can be detrimental to host cell physiology and can lead to virus-associated pathogenesis, including, for oncogenic viruses, cell transformation and cancer progression. Included among these oncogenic viruses is the hepatitis B virus (HBV). Despite the availability of an HBV vaccine, 350-500 million people worldwide are chronically infected with HBV, and a significant number of these chronically infected individuals will develop hepatocellular carcinoma (HCC). Epidemiological studies indicate that chronic infection with HBV is the leading risk factor for the development of HCC. Globally, HCC is the second highest cause of cancer-associated deaths, underscoring the need for understanding mechanisms that regulate HBV replication and the development of HBV-associated HCC. HBV is the prototype member of the Hepadnaviridae family; members of this family of viruses have a narrow host range and predominately infect hepatocytes in their respective hosts. The extremely small and compact hepadnaviral genome, the unique arrangement of open reading frames, and a replication strategy utilizing reverse transcription of an RNA intermediate to generate the DNA genome are distinguishing features of the Hepadnaviridae. In this review, we provide a comprehensive description of HBV biology, summarize the model systems used for studying HBV infections, and highlight potential mechanisms that link a chronic HBV-infection to the development of HCC. For example, the HBV X protein (HBx), a key regulatory HBV protein that is important for HBV replication, is thought to play a cofactor role in the development of HBV-induced HCC, and we highlight the functions of HBx that may contribute to the development of HBV-associated HCC.

A home-brew real-time PCR assay for reliable detection and quantification of mature miR-122

miR-122 is a liver-specific miRNA that has significant gene expression alterations in response to specific pathophysiological circumstances of liver such as drug-induced liver injury, hepatocellular carcinoma, and hepatitis B and C virus infections. Therefore, accurate and precise quantification of miR-122 is very important for clinical diagnostics. However, because of the lack of in vitro diagnostics assays for miR-122 detection and quantification of the existence of an open-source assay could inevitably provide external evaluation by other researchers and the chance of promoting the assay when required. The aim of this study was to develop a Taqman real-time polymerase chain reaction assay, which is capable of robust and reliable quantification of miR-122 in different sample types. We used stem loop methodology to design a specific Taqman real-time polymerase chain reaction assay for miR-122. This technique enabled us to reliably and reproducibly quantify short-length oligonucleotides such as miR-122. The specificity, sensitivity, interassay and intra-assay, and the dynamic range of the assay were experimentally determined by their respective methodology. The assay had a linear dynamic range of 3E to 4.8E miR-122 copies/reaction and the limit of detection was determined to be between 960 and 192 copies/reaction with 95% confidence interval. The assay gave a coefficient of variation for the Ct values of <1.4% and 0.78% for intra-assay and interassay, respectively. Taking into account that miR-122 is expressed in >50,000 copies per hepatocyte, this assay is able to suffice the need for reliable detection and quantification of this miRNA. Therefore, this study can be considered as a start point for standardizing miR-122 quantification.