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Chronic hepatitis B virus (HBV) infection (CHB) is a risk factor for the development of liver fibrosis, cirrhosis, and hepatocellular carcinoma. Covalently closed circular DNA serves as the sole transcription template for all viral RNAs and viral transcription is driven and enhanced by viral promoter and enhancer elements, respectively. Interactions between transcription factors and these cis-elements regulate their activities and change the production levels of viral RNAs. Here, we report the identification of homeobox protein MSX-1 (MSX1) as a novel host restriction factor of HBV in liver. In both HBV-transfected and HBV-infected cells, MSX1 suppresses viral gene expression and genome replication. Mechanistically, MSX1 downregulates enhancer II/core promoter (EnII/Cp) activity via direct binding to an MSX1 responsive element within EnII/Cp, and such binding competes with hepatocyte nuclear factor 4α binding to EnII/Cp due to partial overlap between their respective binding sites. Furthermore, CHB patients in immune active phase express higher levels of intrahepatic MSX1 but relatively lower levels of serum and intrahepatic HBV markers compared to those in immune tolerant phase. Finally, MSX1 was demonstrated to induce viral clearance in two mouse models of HBV persistence, suggesting possible therapeutic potential for CHB.IMPORTANCECovalently closed circular DNA plays a key role for the persistence of hepatitis B virus (HBV) since it serves as the template for viral transcription. Identification of transcription factors that regulate HBV transcription not only provides insights into molecular mechanisms of viral life cycle regulation but may also provide potential antiviral targets. In this work, we identified host MSX1 as a novel restriction factor of HBV transcription. Meanwhile, we observed higher intrahepatic MSX1 expression in chronic hepatitis B virus (CHB) patients in immune active phase compared to those in immune tolerant phase, suggesting possible involvement of MSX1 in the regulation of HBV activity by the host. Lastly, intrahepatic overexpression of MSX1 delivered by recombinant adenoviruses into two mouse models of HBV persistence demonstrated MSX1-mediated repression of HBV in vivo, and MSX1-induced clearance of intrahepatic HBV DNA in treated mice suggested its potential as a therapeutic target for the treatment of CHB.
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Hepatite B Crônica , Hepatite B , Fator de Transcrição MSX1 , Animais , Humanos , Camundongos , DNA Circular , DNA Viral/genética , Hepatite B/metabolismo , Vírus da Hepatite B/fisiologia , RNA Viral , Fatores de Transcrição/genética , Replicação Viral/genética , Fator de Transcrição MSX1/metabolismoRESUMO
BACKGROUND: Low-frequency intrahost single-nucleotide variants of SARS-CoV-2 have been recognized as predictive indicators of selection. However, the impact of vaccination on the intrahost evolution of SARS-CoV-2 remains uncertain at present. METHODS: We investigated the genetic variation of SARS-CoV-2 in individuals who were unvaccinated, partially vaccinated, or fully vaccinated during Shanghai's Omicron BA.2.2 wave. We substantiated the connection between particular amino acid substitutions and immune-mediated selection through a pseudovirus neutralization assay or by cross-verification with the human leukocyte antigen-associated T-cell epitopes. RESULTS: In contrast to those with immunologic naivety or partial vaccination, participants who were fully vaccinated had intrahost variant spectra characterized by reduced diversity. Nevertheless, the distribution of mutations in the fully vaccinated group was enriched in the spike protein. The distribution of intrahost single-nucleotide variants in individuals who were immunocompetent did not demonstrate notable signs of positive selection, in contrast to the observed adaptation in 2 participants who were immunocompromised who had an extended period of viral shedding. CONCLUSIONS: In SARS-CoV-2 infections, vaccine-induced immunity was associated with decreased diversity of within-host variant spectra, with milder inflammatory pathophysiology. The enrichment of mutations in the spike protein gene indicates selection pressure exerted by vaccination on the evolution of SARS-CoV-2.
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Vacinas contra COVID-19 , COVID-19 , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Vacinação , Humanos , SARS-CoV-2/imunologia , SARS-CoV-2/genética , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/virologia , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , China , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Epitopos de Linfócito T/imunologia , Epitopos de Linfócito T/genética , Mutação , Substituição de Aminoácidos , Variação Genética , Masculino , Feminino , Infecções IrruptivasRESUMO
BACKGROUND & AIMS: Nucleo(s)tide analogue (NUC) cessation can lead to HBsAg clearance but also a high rate of virological relapse. However, the effect of pegylated interferon alpha-2a (PegIFN-α-2a) on virological relapse after NUC cessation is unknown. Therefore, this study aimed to evaluate the effect of switching from NUC to PegIFN-α-2a treatment for 48 weeks on virological relapse until week 96. METHODS: In this multicentre randomized controlled clinical trial, 180 non-cirrhotic HBeAg-negative chronic hepatitis B patients on continuous NUC therapy for ≥ 2.5 years with HBV DNA levels < 60 IU/mL were randomized to discontinue NUC (n=90) or receive 48 weeks of PegIFN-α-2a treatment (n=90) and followed up till 96 weeks. The primary endpoint was the virological relapse rate until week 96. RESULTS: Intention-to-treat analysis revealed patients in the interferon monotherapy group had significantly lower cumulative virological relapse rates than the NUC cessation group until week 96 (20.8% vs. 53.6%, P < 0.0001). Consistently, a significantly lower proportion of patients in the interferon monotherapy group had virological relapse than those in the NUC cessation group at 48 weeks off treatment (17.8% vs. 36.7%, P = 0.007). The virological relapse rate positively correlated with HBsAg levels in the NUC cessation group. The interferon monotherapy group had a lower cumulative clinical relapse rate (7.8% vs. 20.9%, P = 0.008) and a higher HBsAg loss rate (21.5% vs. 9.0%, P = 0.03) than the NUC cessation group. CONCLUSIONS: Switching from NUC to PegIFN-α-2a treatment for 48 weeks significantly reduces virological relapse rates and achieves higher HBsAg loss rates than NUC treatment cessation alone in HBeAg-negative chronic hepatitis B patients. IMPACT AND IMPLICATIONS: Nucleo(s)tide analogue (NUC) cessation can lead to HBsAg clearance but also a high rate of virological relapse, but an optimised scheme to reduce the virological relapse rate after NUC withdrawal is yet to be reported. This randomized controlled trial investigated the effect of switching from NUC to PegIFN-α-2a treatment for 48 weeks on virological relapse until week 96 in HBeAg-negative chronic hepatitis B patients. The interferon monotherapy group had a significantly lower cumulative virological relapse rate (20.8% vs. 53.6%, P < 0.0001) and higher HBsAg loss rate (21.5% vs. 9.0%, P= 0.03) than the NUC cessation group until week 96. This provides an optimized strategy for NUC cessation in HBeAg-negative patients. TRIAL REGISTRATION NUMBER: NCT02594293.
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Chronic infection with hepatitis B virus (HBV) is associated with liver cirrhosis and hepatocellular carcinoma. Upon infection of hepatocytes, HBV covalently closed circular DNA (cccDNA) exists as histone-bound mini-chromosome, subjected to transcriptional regulation similar to chromosomal DNA. Here we identify high mobility group AT-hook 1 (HMGA1) protein as a positive regulator of HBV transcription that binds to a conserved ATTGG site within enhancer II/core promoter (EII/Cp) and recruits transcription factors FOXO3α and PGC1α. HMGA1-mediated upregulation of EII/Cp results in enhanced viral gene expression and genome replication. Notably, expression of endogenous HMGA1 was also demonstrated to be upregulated by HBV, which involves HBV X protein (HBx) interacting with SP1 transcription factor to activate HMGA1 promoter. Consistent with these in vitro results, chronic hepatitis B patients in immune tolerant phase display both higher intrahepatic HMGA1 protein levels and higher serum HBV markers compared to patients in inactive carrier phase. Finally, using a mouse model of HBV persistence, we show that targeting endogenous HMGA1 through RNA interference facilitated HBV clearance. These data establish HMGA1 as an important positive regulator of HBV that is reciprocally upregulated by HBV via HBx and also suggest the HMGA1-HBV positive feedback loop as a potential therapeutic target.
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Hepatite B Crônica , Neoplasias Hepáticas , DNA Circular/genética , DNA Circular/metabolismo , DNA Viral/genética , DNA Viral/metabolismo , Proteína HMGA1a/genética , Proteína HMGA1a/metabolismo , Células Hep G2 , Vírus da Hepatite B/genética , Vírus da Hepatite B/metabolismo , Hepatite B Crônica/genética , Humanos , Neoplasias Hepáticas/genética , Transativadores , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Virais Reguladoras e Acessórias , Replicação Viral/genéticaRESUMO
Prolonged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has received much attention since it is associated with mortality and is hypothesized as the cause of long COVID-19 and the emergence of a new variant of concerns. However, a prediction model for the accurate prediction of prolonged infection is still lacking. A total of 2938 confirmed patients with COVID-19 diagnosed by positive reverse transcriptase-polymerase chain reaction tests were recruited retrospectively. This study cohort was divided into a training set (70% of study patients; n = 2058) and a validation set (30% of study patients; n = 880). Univariate and multivariate logistic regression analyses were utilized to identify predictors for prolonged infection. Model 1 included only preadmission variables, whereas Model 2 also included after-admission variables. Nomograms based on variables of Model 1 and Model 2 were built for clinical use. The efficiency of nomograms was evaluated by using the area under the curve, calibration curves, and concordance indexes (C-index). Independent predictors of prolonged infection included in Model 1 were: age ≥75 years, chronic kidney disease, chronic lung disease, partially or fully vaccinated, and booster. Additional independent predictors in Model 2 were: treated with nirmatrelvir/ritonavir more than 5 days after diagnosis and glucocorticoid. The inclusion of after-admission variables in the model slightly improved the discriminatory power (C-index in the training cohort: 0.721 for Model 1 and 0.737 for Model 2; in the validation cohort: 0.699 for Model 1 and 0.719 for Model 2). In our study, we developed and validated predictive models based on readily available variables of preadmission and after-admission for predicting prolonged SARS-CoV-2 infection of patients with COVID-19.
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COVID-19 , Humanos , Idoso , Nomogramas , SARS-CoV-2 , Estudos Retrospectivos , Síndrome de COVID-19 Pós-AgudaRESUMO
Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA), the transcription template for all viral mRNAs, is highly stable and current treatment options cannot effectively induce its clearance. Previously, we established an HBV persistence mouse model based on a clinical isolate (termed BPS) and identified interleukin-21 (IL-21) as a potent inducer of HBV clearance. Lipid nanoparticle (LNP) mediated delivery of mRNA has proven to be a highly safe and effective delivery platform. This work explored the applicability and effectiveness of the mRNA-LNP platform in IL-21-based HBV therapies. First, LNP-encapsulated murine IL-21 mRNA (LNP-IL-21) was prepared, characterized, and demonstrated to engender IL-21 expression in vitro and in vivo. Next, LNP-IL-21 was shown to induce clearance of both serum and intrahepatic HBV antigen and DNA in two HBV persistence mouse models based on BPS and recombinant cccDNA (rcccDNA), respectively, which was associated with HBV-specific humoral and cellular immune responses. Furthermore, peripheral blood mononuclear cells from BPS persistence mice treated ex vivo with LNP-IL-21 and HBV surface antigen (HBsAg) could induce similar HBV clearance upon infusion into recipient mice. These findings indicated that IL-21 combined with mRNA-LNP platform represents a valid and promising strategy for developing novel therapeutics against chronic HBV infection.
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Vírus da Hepatite B , Leucócitos Mononucleares , Animais , Camundongos , Vírus da Hepatite B/genética , Antígenos de Superfície da Hepatite B/genética , Modelos Animais de Doenças , RNA MensageiroRESUMO
During March 2022 to January 2023, two Omicron waves hit Shanghai and caused a massive number of reinfections. To better understand the incidence and clinical characteristics of SARS-CoV-2 reinfection in Shanghai, China, we conducted a multicenter cohort study. COVID-19 patients first infected with BA.2 (March 1, 2022-May 23, 2022) who were quarantined in Huashan Hospital, Renji Hospital, and Shanghai Jing'an Central Hospital were followed up for reinfection from June 1, 2022 to January 31, 2023. Of 897 primary infections, 148 (16.5%) experienced reinfection. Incidence rate of reinfection was 0.66 cases per 1000 person-days. Female gender (adjusted odds ratio [aOR]= 2.19, 95% confidence interval [CI]: 1.29-3.83) was a risk factor for reinfection. The four most common symptoms of reinfections during the circulation of BA.5 sublineages were cough (62.59%), sore throat (54.42%), fatigue (48.98%), and fever (42.57%). Having received a booster vaccination was not associated with reduced severity of reinfection in comparison with not having received booster vaccination. After matched 1:1 by age and sex, we found that reinfections with BA.5 sublineages had significantly lower occurrence and severity of fever, fatigue, sore throat, and cough, as compared to primary infections with BA.5 sublineages. SARS-CoV-2 Omicron reinfections were less severe than Omicron primary infections during the circulation of the same subvariant. Protection offered by both vaccination and previous infection was poor against SARS-CoV-2 reinfection.
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COVID-19 , Faringite , Feminino , Humanos , China/epidemiologia , Estudos de Coortes , Tosse , COVID-19/epidemiologia , Fadiga , Febre , Incidência , Dor , Reinfecção/epidemiologia , SARS-CoV-2 , MasculinoRESUMO
DDX17 is a member of the DEAD-box helicase family proteins involved in cellular RNA folding, splicing, and translation. It has been reported that DDX17 serves as a cofactor of host zinc finger antiviral protein (ZAP)-mediated retroviral RNA degradation and exerts direct antiviral function against Raft Valley fever virus through binding to specific stem-loop structures of viral RNA. Intriguingly, we have previously shown that ZAP inhibits hepatitis B virus (HBV) replication through promoting viral RNA decay, and the ZAP-responsive element (ZRE) of HBV pregenomic RNA (pgRNA) contains a stem-loop structure, specifically epsilon, which serves as the packaging signal for pgRNA encapsidation. In this study, we demonstrated that the endogenous DDX17 is constitutively expressed in human hepatocyte-derived cells but dispensable for ZAP-mediated HBV RNA degradation. However, DDX17 was found to inhibit HBV replication primarily by reducing the level of cytoplasmic encapsidated pgRNA in a helicase-dependent manner. Immunofluorescence assay revealed that DDX17 could gain access to cytoplasm from nucleus in the presence of HBV RNA. In addition, RNA immunoprecipitation and electrophoretic mobility shift assays demonstrated that the enzymatically active DDX17 competes with HBV polymerase to bind to pgRNA at the 5' epsilon motif. In summary, our study suggests that DDX17 serves as an intrinsic host restriction factor against HBV through interfering with pgRNA encapsidation. IMPORTANCE Hepatitis B virus (HBV) chronic infection, a long-studied but yet incurable disease, remains a major public health concern worldwide. Given that HBV replication cycle highly depends on host factors, deepening our understanding of the host-virus interaction is thus of great significance in the journey of finding a cure. In eukaryotic cells, RNA helicases of the DEAD box family are highly conserved enzymes involved in diverse processes of cellular RNA metabolism. Emerging data have shown that DDX17, a typical member of the DEAD box family, functions as an antiviral factor through interacting with viral RNA. In this study, we, for the first time, demonstrate that DDX17 inhibits HBV through blocking the formation of viral replication complex, which not only broadens the antiviral spectrum of DDX17 but also provides new insight into the molecular mechanism of DDX17-mediated virus-host interaction.
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Capsídeo/metabolismo , RNA Helicases DEAD-box/metabolismo , Vírus da Hepatite B/fisiologia , RNA Viral/metabolismo , Replicação Viral , Linhagem Celular , Linhagem Celular Tumoral , Citoplasma/metabolismo , RNA Helicases DEAD-box/química , Produtos do Gene pol/metabolismo , Vírus da Hepatite B/genética , Humanos , Conformação de Ácido Nucleico , Domínios Proteicos , Estabilidade de RNA , RNA Viral/química , RNA Viral/genética , Proteínas de Ligação a RNA/metabolismoRESUMO
Hepatitis B virus (HBV) small (S) envelope protein has the intrinsic ability to direct the formation of small spherical subviral particles (SVPs) in eukaryotic cells. However, the molecular mechanism underlying the morphogenesis of SVPs from the monomeric S protein initially synthesized at the endoplasmic reticulum (ER) membrane remains largely elusive. Structure prediction and extensive mutagenesis analysis suggested that the amino acid residues spanning W156 to R169 of S protein form an amphipathic alpha helix and play essential roles in SVP production and S protein metabolic stability. Further biochemical analyses showed that the putative amphipathic alpha helix was not required for the disulfide-linked S protein oligomerization, but was essential for SVP morphogenesis. Pharmacological disruption of vesicle trafficking between the ER and Golgi complex in SVP producing cells supported the hypothesis that S protein-directed SVP morphogenesis takes place at the ER-Golgi intermediate compartment (ERGIC). Moreover, it was demonstrated that S protein is degraded in hepatocytes via a 20S proteasome-dependent, but ubiquitination-independent non-classic ER-associated degradation (ERAD) pathway. Taken together, the results reported herein favor a model in which the amphipathic alpha helix at the antigenic loop of S protein attaches to the lumen leaflet to facilitate SVP budding from the ERGIC compartment, whereas the failure of budding process may result in S protein degradation by 20S proteasome in an ubiquitination-independent manner.Importance Subviral particles are the predominant viral product produced by HBV-infected hepatocytes. Their levels exceed the virion particles by 10,000 to 100,000-fold in the blood of HBV infected individuals. The high levels of SVPs, or HBV surface antigen (HBsAg), in the circulation induces immune tolerance and contributes to the establishment of persistent HBV infection. The loss of HBsAg, often accompanied by appearance of anti-HBs antibodies, is the hallmark of durable immune control of HBV infection. Therapeutic induction of HBsAg loss is, therefore, considered to be essential for the restoration of host antiviral immune response and functional cure of chronic hepatitis B. Our findings on the mechanism of SVP morphogenesis and S protein metabolism will facilitate the rational discovery and development of antiviral drugs to achieve this therapeutic goal.
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SARS-CoV-2 Omicron variant seemed to cause milder disease compared to previous predominated variants. We aimed to conduct a meta-analysis to assess the pooled proportion of nonsevere disease and asymptomatic infection among COVID-19 patients infected with Omicron and Delta. We searched PubMed, Embase, Web of Science, and China National Knowledge Infrastructure (CNKI) databases. We included studies of SARS-CoV-2 Omicron infection from November 1, 2021, to April 18, 2022, and studies of Delta infection from October 1, 2020, to June 30, 2022. Studies without corresponding data, with less than 50 patients, or obviously biased concerning main outcome were excluded. Meta-analysis was performed in R 4.2.0 with the "meta" package. Subgroup analyses were conducted by study group and vaccination status. The pooled proportion of asymptomatic infection and nonsevere disease with Omicron were 25.5% (95% confidence interval [CI] 17.0%-38.2%) and 97.9% (95% CI 97.1%-98.7%), significantly higher than those of Delta with 8.4% (95% CI 4.4%-16.2%) and 91.4% (95% CI 87.0%-96.0%). During Omicron wave, children and adolescents had higher proportion of asymptomatic infection, SOTR and the elderly had lower proportion of nonsevere disease, vaccination of a booster dose contributed to higher proportion of both asymptomatic infection and nonsevere disease. This study estimates the pooled proportion of asymptomatic infection and nonsevere disease caused by SARS-CoV-2 Omicron compared to other predominant variants. The result has important implications for future policy making.
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Infecções Assintomáticas , COVID-19 , Adolescente , Idoso , Infecções Assintomáticas/epidemiologia , COVID-19/epidemiologia , Criança , China , Humanos , SARS-CoV-2RESUMO
HBx plays a significant role in the cccDNA epigenetic modification regulating the hepatitis B virus (HBV) life cycle and in hepatocyte proliferation and carcinogenesis. By using the sleeping-beauty transposon system, we constructed a tetracycline-induced HBx-expressing stable cell line, SBHX21. HBx with a HiBiT tag can be quickly detected utilizing a NanoLuc-based HiBiT detection system. By screening a drug library using SBHX21 cells, we identified estradiol benzoate as a novel anti-HBx agent. Estradiol benzoate also markedly reduced the production of HBeAg, HBsAg, HBV pgRNA, and HBV DNA in a dose-dependent manner, suggesting that estradiol benzoate could be an anti-HBV agent. Docking model results revealed that estradiol benzoate binds to HBx at TRP87 and TRP107. Collectively, our results suggest that estradiol benzoate inhibits the HBx protein and HBV transcription and replication, which may serve as a novel anti-HBV molecular compound for investigating new treatment strategies for HBV infection.
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Vírus da Hepatite B , Transativadores , Estradiol/análogos & derivados , Células Hep G2 , Vírus da Hepatite B/metabolismo , Humanos , Luciferases , Transativadores/genética , Transativadores/metabolismo , Proteínas Virais Reguladoras e Acessórias/metabolismo , Replicação ViralRESUMO
DNA transfection is routinely used for delivering expression of gene of interest to target cells. Transfected DNA has been known to activate cellular DNA sensor(s) and innate immune responses, but the effects of such responses on transfected DNA are not fully understood. STING (stimulator of interferon genes) is an important adaptor protein in cellular innate immune response to various DNA and RNA stimuli and upon activation induces significant type I interferon responses. In this work, we characterized the effects of STING on gene expression driven by transfected double-stranded DNA. We observed that gene expression from transfected DNA was repressed in the presence of overexpressed STING, but increased if endogenous STING was knocked down through RNA interference. Endogenous chromosomal genes and chromosome-integrated exogenous genes were not affected by such STING-mediated restriction, which did not depend on DNA circularity or linearity, promoter used, or bacterial sequences in transfected DNA. Mechanistically, STING-mediated repression of transfected DNA correlates with reduced mRNA levels, and partially involves the induction of interferon ß production by STING. Collectively, these data indicate that episomal double-stranded DNA is targeted by STING-mediated cell defense.
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DNA/metabolismo , Proteínas de Membrana/metabolismo , Sequência de Bases , Cromossomos Humanos/genética , Regulação da Expressão Gênica , Células HEK293 , Humanos , Interferon beta/metabolismo , TransfecçãoRESUMO
BACKGROUND: Although the Asian Pacific Association for the Study of the Liver acute-on-chronic liver failure (ACLF) research consortium (AARC) ACLF score is easy to use in patients with hepatitis b virus-related ACLF (HBV-ACLF), serum lactate is not routinely tested in primary hospitals, and its value may be affected by some interference factors. Neutrophil-to-lymphocyte ratio (NLR) is used to assess the status of bacterial infection (BI) or outcomes in patients with various diseases. We developed an NLR-based AARC ACLF score and compared it with the existing model. METHODS: A total of 494 HBV-ACLF patients, enrolled in four tertiary academic hospitals in China with 90-day follow-up, were analysed. Prognostic performance of baseline NLR and lactate were compared between cirrhotic and non-cirrhotic subgroups via the receiver operating curve and Kaplan-Meier analyses. A modified AARC ACLF (mAARC ACLF) score using NLR as a replacement for lactate was developed (n = 290) and validated (n = 204). RESULTS: There were significantly higher baseline values of NLR in non-survivors, patients with admission BI, and those with higher grades of ACLF compared with the control groups. Compared with lactate, NLR better reflected BI status in the cirrhotic subgroup, and was more significantly correlated with CTP, MELD, MELD-Na, and the AARC score. NLR was an independent predictor of 90-day mortality, and was categorized into three risk grades (< 3.10, 3.10-4.78, and > 4.78) with 90-day cumulative mortalities of 8%, 21.2%, and 77.5% in the derivation cohort, respectively. The mAARC ACLF score, using the three grades of NLR instead of corresponding levels of lactate, was superior to the other four scores in predicting 90-day mortality in the derivation (AUROC 0.906, 95% CI 0.872-0.940, average P < 0.001) and validation cohorts (AUROC 0.913, 95% CI 0.876-0.950, average P < 0.01), with a considerable performance in predicting 28-day mortality in the two cohorts. CONCLUSIONS: The prognostic value of NLR is superior to that of lactate in predicting short-term mortality risk in cirrhotic and non-cirrhotic patients with HBV-ACLF. NLR can be incorporated into the AARC ACLF scoring system for improving its prognostic accuracy and facilitating the management guidance in patients with HBV-ACLF in primary hospitals.
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Insuficiência Hepática Crônica Agudizada , Vírus da Hepatite B , Humanos , Linfócitos , Neutrófilos , Prognóstico , Estudos RetrospectivosRESUMO
Background: The natural history of chronic hepatitis B virus (HBV) infection was divided into 4 phases. Patients in the inactive carrier (IC) status and immune tolerant (IT) phase had normal alanine aminotransferase levels but huge different viral loads. The mechanism underlying low viral replication status in IC phase is unknown. Methods: We determined the intrahepatic transcriptomes of 83 chronic hepatitis B patients by microarray analysis of liver biopsies, and screened the effect of differentially regulated genes on HBV replication using specific small interfering RNAs in vitro. Results: The gene profile distinguishing active chronic hepatitis from IT and IC was predominantly composed of immune-related genes. The liver transcriptomes between the IT and IC phase were largely similar, and 109 expressed genes were significantly different. By performing systematic screening, 5 candidate genes including EVA1A, which were expressed at a relative higher level in IC phase than IT, were identified to regulate HBV replication and gene expression in cellular models. Conclusions: The immune-related pathways were up-regulated in the active chronic hepatitis phase but not in the IT and IC phase. A number of intrahepatic genes highly expressed in the IC phase may participate in the control of HBV replication and determine the inactive status of HBV infection.
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Portador Sadio , Regulação da Expressão Gênica/fisiologia , Vírus da Hepatite B/fisiologia , Hepatite B Crônica/imunologia , Hepatite B Crônica/virologia , Fígado/metabolismo , Adulto , Idoso , Linhagem Celular Tumoral , DNA Viral/sangue , Feminino , Regulação da Expressão Gênica/imunologia , Hepatite B Crônica/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Transcriptoma/genética , Replicação Viral , Adulto JovemRESUMO
Angiogenesis has been proven to play an important role in the progression of hepatocellular carcinoma (HCC). However, the molecular mechanism underlying HCC angiogenesis is not well understood. In this study, Prospero-related homeobox 1 (PROX1) was identified as a novel proangiogenic factor in HCC cell lines and tissues. A strong positive correlation was found between the levels of PROX1 and microvessel density in HCC tissues. Knockdown of PROX1 expression in HCC cells significantly inhibited the in vitro capillary tube formation by human vascular endothelial cells and in vivo angiogenesis of HCC, while overexpression of PROX1 in HCC cells induced the opposite effects. PROX1 and nuclear factor κB p65 expression levels were positively correlated in both HCC tissues and cell lines. PROX1 enhances the nuclear accumulation of p65 and stabilizes p65 by recruiting ubiquitin-specific protease 7 to prevent p65 ubiquitination. Consequently, PROX1 activated nuclear factor κB signaling and selectively promoted expression of the proangiogenic interleukin-8 (IL-8) by epigenetically stimulating the IL-8 promoter. Finally, progression of high PROX1 expression HCC in tumor xenograft mice could be effectively contained by an anti-IL-8 monoclonal antibody. CONCLUSIONS: We have identified PROX1 as a crucial promoter of HCC angiogenesis; our study provides an insight into PROX1's function in HCC progression and the potential therapeutic application of anti-IL-8 antibody in high PROX1 expression HCC patients. (Hepatology 2017;66:1894-1909).
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Carcinoma Hepatocelular/metabolismo , Proteínas de Homeodomínio/metabolismo , Interleucina-8/metabolismo , Neoplasias Hepáticas/metabolismo , Neovascularização Patológica , Proteínas Supressoras de Tumor/metabolismo , Animais , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Humanos , Interleucina-8/antagonistas & inibidores , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Camundongos , Camundongos Nus , Terapia de Alvo Molecular , Estabilidade Proteica , Distribuição Aleatória , Fator de Transcrição RelA/metabolismo , Ativação Transcricional , Peptidase 7 Específica de Ubiquitina/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Background: The fulminant form of hepatitis B-related acute liver failure (FHB-ALF) is a rare but highly fatal outcome of acute hepatitis B virus (HBV) infection. Its related host factors have not been studied to our knowledge. Methods: To identify functionally relevant biological pathway(8) in FHB-ALF pathogenesis, pathway enrichment analysis was conducted on a data set of rare case-specific variants derived from exomic sequencing of 10 unrelated cases. Key variants in identified pathways were validated using 312 controls with HBV disease. Mechanistic studies of a recurrent Toll-like receptor (TLR) 2 gene (TLR2) variant were performed in vitro and in vivo. Results: The TLR signaling pathway was highly enriched, with associated variants found in 9 of the 10 cases. Notably, a rare heterozygous single-nucleotide variation causing F679I mutation in TLR2 was identified in 2 unrelated cases. In vitro analysis demonstrated F679I to cause loss of function. In both heterozygous and homozygous TLR2 knockout mice, injection of HBV replicon plasmid resulted in more prominent alanine aminotransferase elevations and hepatic necroinflammation than in wild-type mice. Mechanistic analyses demonstrated reduced regulatory T-cell percentages in postexposure TLR2 knockout mice. Conclusions: TLR2 signaling is very likely impaired in patients with FHB-ALF. The recurrence of rare case-specific TLR2 variant strongly suggests mechanistic contribution to fulminancy in HBV infection.
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Hepatite B/complicações , Falência Hepática Aguda/genética , Falência Hepática Aguda/virologia , Transdução de Sinais , Linfócitos T Reguladores/metabolismo , Receptor 2 Toll-Like/genética , Adulto , Alanina Transaminase/metabolismo , Animais , DNA Viral/genética , Feminino , Antígenos do Núcleo do Vírus da Hepatite B/sangue , Vírus da Hepatite B , Humanos , Fígado/virologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Mutação , Adulto JovemRESUMO
Melanoma is the most aggressive type of skin cancer. Melanoma has an extremely poor prognosis because of its high potential for vascular invasion, metastasis and recurrence. The mechanism of melanoma metastasis is not well understood. ATP-binding cassette sub-family B member 5 (ABCB5) plays a key role in melanoma growth. However, it is uncertain what function ABCB5 may exert in melanoma metastasis. In this report, we for the first time demonstrate ABCB5 as a crucial factor that promotes melanoma metastasis. ABCB5 positive (ABCB5+) malignant melanoma initiating cells (MMICs) display a higher metastatic potential compared with ABCB5 negative (ABCB5-) melanoma subpopulation. Knockdown of ABCB5 expression reduces melanoma cell migration and invasion in vitro and melanoma pulmonary metastasis in tumor xenograft mice. ABCB5 and NF-κB p65 expression levels are positively correlated in both melanoma tissues and cell lines. Consequently, ABCB5 activates the NF-κB pathway by inhibiting p65 ubiquitination to enhance p65 protein stability. Our finding highlights ABCB5 as a novel pro-metastasis factor and provides a potential therapeutic target for melanoma.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Melanoma/metabolismo , Melanoma/patologia , Metástase Neoplásica , Fator de Transcrição RelA/metabolismo , Subfamília B de Transportador de Cassetes de Ligação de ATP , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/deficiência , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Animais , Movimento Celular , Células Cultivadas , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Estabilidade ProteicaRESUMO
Mild calcination in ozone of a (POSS)-Sn-(POSS) complex grafted on silica generated a heterogenized catalyst that mostly retained the tetrahedral coordination of its homogeneous precursor, as evidenced by spectroscopic characterizations using EXAFS, NMR, UV-vis, and DRIFT. The Sn centers are accessible and uniform and can be quantified by stoichiometric pyridine poisoning. This Sn-catalyst is active in hydride transfer reactions as a typical solid Lewis acid. However, the Sn centers can also create Brønsted acidity with alcohol by binding the alcohol strongly as alkoxide and transferring the hydroxyl H to the neighboring Sn-O-Si bond. The resulting acidic silanol is active in epoxide ring opening and acetalization reactions.
RESUMO
Endogenous viral elements (EVE) in animal genomes are the fossil records of ancient viruses and provide invaluable information on the origin and evolution of extant viruses. Extant hepadnaviruses include avihepadnaviruses of birds and orthohepadnaviruses of mammals. The core promoter (Cp) of hepadnaviruses is vital for viral gene expression and replication. We previously identified in the budgerigar genome two EVEs that contain the full-length genome of an ancient budgerigar hepadnavirus (eBHBV1 and eBHBV2). Here, we found eBHBV1 Cp and eBHBV2 Cp were active in several human and chicken cell lines. A region from nt -85 to -11 in eBHBV1 Cp was critical for the promoter activity. Bioinformatic analysis revealed a putative binding site of nuclear factor Y (NF-Y), a ubiquitous transcription factor, at nt -64 to -50 in eBHBV1 Cp. The NF-Y core binding site (ATTGG, nt -58 to -54) was essential for eBHBV1 Cp activity. The same results were obtained with eBHBV2 Cp and duck hepatitis B virus Cp. The subunit A of NF-Y (NF-YA) was recruited via the NF-Y core binding site to eBHBV1 Cp and upregulated the promoter activity. Finally, the NF-Y core binding site is conserved in the Cps of all the extant avihepadnaviruses but not of orthohepadnaviruses. Interestingly, a putative and functionally important NF-Y core binding site is located at nt -21 to -17 in the Cp of human hepatitis B virus. In conclusion, our findings have pinpointed an evolutionary conserved and functionally critical NF-Y binding element in the Cps of avihepadnaviruses.
Assuntos
Fator de Ligação a CCAAT/genética , Elementos de DNA Transponíveis , DNA Viral/genética , Genoma , Hepadnaviridae/genética , Hepatócitos/metabolismo , Animais , Sítios de Ligação , Evolução Biológica , Doenças das Aves/virologia , Fator de Ligação a CCAAT/química , Fator de Ligação a CCAAT/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Embrião de Galinha , Galinhas , Sequência Conservada , DNA Viral/metabolismo , Extinção Biológica , Fibroblastos/metabolismo , Fibroblastos/virologia , Fósseis , Células HEK293 , Hepadnaviridae/classificação , Hepadnaviridae/metabolismo , Infecções por Hepadnaviridae/veterinária , Infecções por Hepadnaviridae/virologia , Vírus da Hepatite B/genética , Vírus da Hepatite B/metabolismo , Hepatócitos/virologia , Interações Hospedeiro-Patógeno , Humanos , Melopsittacus , Filogenia , Regiões Promotoras Genéticas , Ligação ProteicaRESUMO
Global adoption of hepatitis B virus (HBV) vaccines has greatly reduced new HBV infections. Current HBV vaccines are liquid suspensions containing recombinant hepatitis B surface antigen (HBsAg) particles mixed with aluminum phosphate or aluminum hydroxide. Refrigeration (2-8°C) as recommended for vaccine transport and storage may be unachievable in certain HBV-prevalent developing countries or regions. In this study, we stored yeast-expressed HBsAg and aluminum hydroxide separately at the standard (4°C) and elevated temperature (25, 37, or 45°C) for 14, 23, and 30 days, then mixed them and used the mixture to vaccinate mice with a prime-boost program. The antisera from all the vaccinated mice successfully inhibited HBV infection of HepG2 cells stably expressing HBV receptor sodium taurocholate cotransporting polypeptide. Furthermore, no serum HBsAg was detected in vaccinated mice on Day 1 post-hydrodynamic injection (HDI) of an HBV replicon plasmid and onwards, accompanied with an increasing anti-HBsAg antibody (HBsAb) level. In contrast, serum HBsAg in phosphate-buffered saline (PBS)-injected mice peaked on Day 4 post-HDI and was cleared on Day 14 post-HDI, which coincided with appearance of HBsAb on Day 7 post-HDI, suggesting a typical HBV acute infection process. HBV DNA peaked on Day 4 post-HDI in vaccinated mice, its level significantly lower than that in PBS-injected mice on Day 7 post-HDI, and showed a higher clearance rate. Taken together, we conclude that storing recombinant HBsAg at 25, 37, or 45°C for 14-30 days does not impair its immunogenicity in mice.