Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 46
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Virol ; 97(10): e0128723, 2023 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-37800948

RESUMO

IMPORTANCE: The Kelch-like ECH-associated protein 1 (Keap1)/NF-E2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway is one of the most important defense mechanisms against oxidative stress. We previously reported that a cellular hydrogen peroxide scavenger protein, peroxiredoxin 1, a target gene of transcription factor Nrf2, acts as a novel HBV X protein (HBx)-interacting protein and negatively regulates hepatitis B virus (HBV) propagation through degradation of HBV RNA. This study further demonstrates that the Nrf2/ARE signaling pathway is activated during HBV infection, eventually leading to the suppression of HBV replication. We provide evidence suggesting that Keap1 interacts with HBx, leading to Nrf2 activation and inhibition of HBV replication via suppression of HBV core promoter activity. This study raises the possibility that activation of the Nrf2/ARE signaling pathway is a potential therapeutic strategy against HBV. Our findings may contribute to an improved understanding of the negative regulation of HBV replication by the antioxidant response.


Assuntos
Vírus da Hepatite B , Hepatite B , Proteína 1 Associada a ECH Semelhante a Kelch , Transdução de Sinais , Replicação Viral , Humanos , Elementos de Resposta Antioxidante , Hepatite B/genética , Vírus da Hepatite B/fisiologia , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo
2.
PLoS Pathog ; 18(3): e1009983, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35312737

RESUMO

Intracellular transport via microtubule-based dynein and kinesin family motors plays a key role in viral reproduction and transmission. We show here that Kinesin Family Member 4 (KIF4) plays an important role in HBV/HDV infection. We intended to explore host factors impacting the HBV life cycle that can be therapeutically addressed using siRNA library transfection and HBV/NLuc (HBV/NL) reporter virus infection in HepG2-hNTCP cells. KIF4 silencing resulted in a 3-fold reduction in luciferase activity following HBV/NL infection. KIF4 knockdown suppressed both HBV and HDV infection. Transient KIF4 depletion reduced surface and raised intracellular NTCP (HBV/HDV entry receptor) levels, according to both cellular fractionation and immunofluorescence analysis (IF). Overexpression of wild-type KIF4 but not ATPase-null KIF4 mutant regained the surface localization of NTCP and significantly restored HBV permissiveness in these cells. IF revealed KIF4 and NTCP colocalization across microtubule filaments, and a co-immunoprecipitation study revealed that KIF4 interacts with NTCP. KIF4 expression is regulated by FOXM1. Interestingly, we discovered that RXR agonists (Bexarotene, and Alitretinoin) down-regulated KIF4 expression via FOXM1-mediated suppression, resulting in a substantial decrease in HBV-Pre-S1 protein attachment to HepG2-hNTCP cell surface and subsequent HBV infection in both HepG2-hNTCP and primary human hepatocyte (PXB) (Bexarotene, IC50 1.89 ± 0.98 µM) cultures. Overall, our findings show that human KIF4 is a critical regulator of NTCP surface transport and localization, which is required for NTCP to function as a receptor for HBV/HDV entry. Furthermore, small molecules that suppress or alleviate KIF4 expression would be potential antiviral candidates targeting HBV and HDV entry.


Assuntos
Vírus da Hepatite B , Vírus Delta da Hepatite , Cinesinas , Transportadores de Ânions Orgânicos Dependentes de Sódio , Simportadores , Internalização do Vírus , Família , Células Hep G2 , Vírus da Hepatite B/fisiologia , Vírus Delta da Hepatite/fisiologia , Humanos , Cinesinas/genética , Transportadores de Ânions Orgânicos Dependentes de Sódio/genética , Transportadores de Ânions Orgânicos Dependentes de Sódio/metabolismo , Receptores X de Retinoides/agonistas , Simportadores/genética , Simportadores/metabolismo
3.
Sensors (Basel) ; 23(11)2023 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-37299733

RESUMO

Glucose monitoring is key to the management of diabetes mellitus to maintain optimal glucose control whilst avoiding hypoglycemia. Non-invasive continuous glucose monitoring techniques have evolved considerably to replace finger prick testing, but still require sensor insertion. Physiological variables, such as heart rate and pulse pressure, change with blood glucose, especially during hypoglycemia, and could be used to predict hypoglycemia. To validate this approach, clinical studies that contemporaneously acquire physiological and continuous glucose variables are required. In this work, we provide insights from a clinical study undertaken to study the relationship between physiological variables obtained from a number of wearables and glucose levels. The clinical study included three screening tests to assess neuropathy and acquired data using wearable devices from 60 participants for four days. We highlight the challenges and provide recommendations to mitigate issues that may impact the validity of data capture to enable a valid interpretation of the outcomes.


Assuntos
Diabetes Mellitus Tipo 1 , Hipoglicemia , Dispositivos Eletrônicos Vestíveis , Humanos , Automonitorização da Glicemia/métodos , Glicemia , Estudos Longitudinais
4.
J Virol ; 95(15): e0076721, 2021 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-33980595

RESUMO

Hepatitis B virus (HBV) is a stealth virus that exhibits only minimal induction of the interferon system, which is required for both innate and adaptive immune responses. However, 90% of acutely infected adults can clear the virus, suggesting the presence of additional mechanisms that facilitate viral clearance. Here, we report that Maf bZIP transcription factor F (MafF) promotes host defense against infection with HBV. Using a small interfering RNA (siRNA) library and an HBV/NanoLuc (NL) reporter virus, we screened to identify anti-HBV host factors. Our data showed that silencing of MafF led to a 6-fold increase in luciferase activity after HBV/NL infection. Overexpression of MafF reduced HBV core promoter transcriptional activity, which was relieved upon mutation of the putative MafF binding region. Loss of MafF expression through CRISPR/Cas9 editing (in HepG2-hNTCP-C4 cells) or siRNA silencing (in primary hepatocytes [PXB cells]) induced HBV core RNA and HBV pregenomic RNA (pgRNA) levels, respectively, after HBV infection. MafF physically binds to the HBV core promoter and competitively inhibits HNF-4α binding to an overlapping sequence in the HBV enhancer II sequence (EnhII), as seen by chromatin immunoprecipitation (ChIP) analysis. MafF expression was induced by interleukin-1ß (IL-1ß) or tumor necrosis factor alpha (TNF-α) treatment in both HepG2 and PXB cells, in an NF-κB-dependent manner. Consistently, MafF expression levels were significantly enhanced and positively correlated with the levels of these cytokines in patients with chronic HBV infection, especially in the immune clearance phase. IMPORTANCE HBV is a leading cause of chronic liver diseases, infecting about 250 million people worldwide. HBV has developed strategies to escape interferon-dependent innate immune responses. Therefore, the identification of other anti-HBV mechanisms is important for understanding HBV pathogenesis and developing anti-HBV strategies. MafF was shown to suppress transcription from the HBV core promoter, leading to significant suppression of the HBV life cycle. Furthermore, MafF expression was induced in chronic HBV patients and in primary human hepatocytes (PXB cells). This induction correlated with the levels of inflammatory cytokines (IL-1ß and TNF-α). These data suggest that the induction of MafF contributes to the host's antiviral defense by suppressing transcription from selected viral promoters. Our data shed light on a novel role for MafF as an anti-HBV host restriction factor.


Assuntos
Hepatite B Crônica/patologia , Imunidade Inata/imunologia , Fator de Transcrição MafF/metabolismo , Proteínas Nucleares/metabolismo , Transcrição Gênica/genética , Sistemas CRISPR-Cas/genética , Linhagem Celular Tumoral , Células Hep G2 , Vírus da Hepatite B/genética , Vírus da Hepatite B/fisiologia , Humanos , Interleucina-1beta/imunologia , Fator de Transcrição MafF/genética , Proteínas Nucleares/genética , Regiões Promotoras Genéticas/genética , Interferência de RNA , RNA Interferente Pequeno/genética , Fator de Necrose Tumoral alfa/imunologia
5.
Hepatology ; 73(2): 520-532, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32446278

RESUMO

BACKGROUND AND AIMS: An efficient cell-culture system for hepatitis B virus (HBV) is indispensable for research on viral characteristics and antiviral reagents. Currently, for the HBV infection assay in cell culture, viruses derived from HBV genome-integrated cell lines of HepG2.2.15 or HepAD-38 are commonly used. However, these viruses are not suitable for the evaluation of polymorphism-dependent viral characteristics or resistant mutations against antiviral reagents. HBV obtained by the transient transfection of the ordinary HBV molecular clone has limited infection efficiencies in cell culture. APPROACH AND RESULTS: We found that an 11-amino-acid deletion (d11) in the preS1 region enhances the infectivity of cell-culture-generated HBV (HBVcc) to sodium taurocholate cotransporting polypeptide-transduced HepG2 (HepG2/NTCP) cells. Infection of HBVcc derived from a d11-introduced genotype C strain (GTC-d11) was ~10-fold more efficient than infection of wild-type GTC (GTC-wt), and the number of infected cells was comparable between GTC-d11- and HepG2.2.15-derived viruses when inoculated with the same genome equivalents. A time-dependent increase in pregenomic RNA and efficient synthesis of covalently closed circular DNA were detected after infection with the GTC-d11 virus. The involvement of d11 in the HBV large surface protein in the enhanced infectivity was confirmed by an HBV reporter virus and hepatitis D virus infection system. The binding step of the GTC-d11 virus onto the cell surface was responsible for this efficient infection. CONCLUSIONS: This system provides a powerful tool for studying the infection and propagation of HBV in cell culture and also for developing the antiviral strategy against HBV infection.


Assuntos
Técnicas de Cultura de Células/métodos , Antígenos de Superfície da Hepatite B/metabolismo , Vírus da Hepatite B/patogenicidade , Hepatite B/virologia , Precursores de Proteínas/metabolismo , Antivirais/farmacologia , Antivirais/uso terapêutico , Avaliação Pré-Clínica de Medicamentos/métodos , Células Hep G2 , Hepatite B/tratamento farmacológico , Hepatite B/patologia , Antígenos de Superfície da Hepatite B/genética , Vírus da Hepatite B/efeitos dos fármacos , Vírus da Hepatite B/genética , Humanos , Precursores de Proteínas/genética
6.
Biochem Biophys Res Commun ; 567: 1-8, 2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34130179

RESUMO

Natural product-derived crude drugs are expected to yield an abundance of new drugs to treat infectious diseases. Hepatitis C virus (HCV) is an oncogenic virus that significantly impacts public health. In this study, we sought to identify anti-HCV compounds in extracts of natural products. A total of 110 natural compounds extracted from several herbal medicine plants were examined for antiviral activity against HCV. Using a Huh7-mCherry-NLS-IPS reporter system for HCV infection, we first performed a rapid screening for anti-HCV compounds extracted from crude drugs. The compounds threo-2,3-bis(4-hydroxy-3-methoxyphenyl)-3-butoxypropan-1-ol (#106) and medioresinol (#110), which were extracted from Crataegus cuneate, exhibited anti-HCV activity and significantly inhibited HCV production in a dose-dependent manner. Analyses using HCV pseudoparticle and subgenomic replicon systems indicated that compounds #106 and #110 specifically inhibit HCV RNA replication but not viral entry or translation. Interestingly, compound #106 also inhibited the replication and production of hepatitis A virus. Our findings suggest that C. cuneate is a new source for novel anti-hepatitis virus drug development.


Assuntos
Antivirais/farmacologia , Hepacivirus/efeitos dos fármacos , Hepatite C/tratamento farmacológico , Extratos Vegetais/farmacologia , Antivirais/química , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Crataegus/química , Hepacivirus/fisiologia , Humanos , Extratos Vegetais/química , Plantas Medicinais/química , Replicação Viral/efeitos dos fármacos
7.
Microbiol Immunol ; 65(9): 352-372, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33990999

RESUMO

An estimated 8-10 million people suffer from viral hepatitis in Egypt. Hepatitis A virus (HAV) and hepatitis E virus (HEV) are the major causes of viral hepatitis in Egypt as 50% or more of the Egyptian population are already exposed to HAV infection by the age of 15. In addition, over 60% of the Egyptian population test seropositive for anti-HEV in the first decade of life. HEV mainly causes self-limiting hepatitis; however, cases of fulminant hepatitis and liver failure were reported in Egypt. Hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis D virus (HDV) are the main causes of chronic hepatitis, liver cirrhosis, and liver cancer (hepatocellular carcinoma [HCC]) in Egypt. Globally, Egypt had the highest age-standardized death rate due to cirrhosis from 1990 to 2017. The prevalence rate of HBV (1.3%-1.5%) has declined after national infantile immunization. Coinfection of HBV patients with HDV is common in Egypt because HDV antibodies (IgG) vary in range from 8.3% to 43% among total HBV patients. After the conduction of multiple national programs to control HCV infection, a lower rate of HCV prevalence (4.6%) was recently reported. Data about the incidence of HCV after treatment with direct antiviral agents (DAAs) are lacking. An HCC incidence of 29/1000/year in cirrhotic patients after DAA treatment is reported. A higher rate of infiltrative pattern among HCC patients after DAA treatment is also recognized. Viral hepatitis is one of the major public health concerns in Egypt that needs more attention and funding from health policymakers.


Assuntos
Carcinoma Hepatocelular , Hepatite B , Hepatite Viral Humana , Neoplasias Hepáticas , Antivirais/uso terapêutico , Carcinoma Hepatocelular/epidemiologia , Egito/epidemiologia , Hepatite Viral Humana/epidemiologia , Humanos , Neoplasias Hepáticas/epidemiologia
8.
J Consum Aff ; 55(1): 151-178, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33821035

RESUMO

We use qualitative interviews to study subsistence consumers confronting the global, pervasive and extended challenges of COVID-19, encompassing literally all realms of daily life. For subsistence consumers whose circumstances are filled with day-to-day uncertainty and a small margin of error to begin with, the pandemic has led to manifold uncertainties and a disappearing margin of error, with potentially lethal consequences. Their constraints to thinking and lack of self-confidence arising from both low income and low literacy are magnified in the face of the complex, invisible pandemic and the fear and panic it has caused. Characteristic relational strengths are weakened with social distancing and fear of infection. Yet, subsistence consumers display humanity in catastrophe, and confront the uncontrollable by reiterating a higher power. Consumption is reduced to the very bare essentials and income generation involves staying the course versus finding any viable alternative. We derive implications for consumer affairs.

9.
J Virol ; 93(6)2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30567989

RESUMO

Hepatitis B virus (HBV) infection is a major risk factor for the development of chronic liver diseases, including cirrhosis and hepatocellular carcinoma (HCC). A growing body of evidence suggests that HBV X protein (HBx) plays a crucial role in viral replication and HCC development. Here, we identified peroxiredoxin 1 (Prdx1), a cellular hydrogen peroxide scavenger, as a novel HBx-interacting protein. Coimmunoprecipitation analysis coupled with site-directed mutagenesis revealed that the region from amino acids 17 to 20 of the HBx, particularly HBx Cys17, is responsible for the interaction with Prdx1. Knockdown of Prdx1 by siRNA significantly increased the levels of intracellular HBV RNA, HBV antigens, and extracellular HBV DNA, whereas knockdown of Prdx1 did not increase the activities of HBV core, enhancer I (Enh1)/X, preS1, and preS2/S promoters. Kinetic analysis of HBV RNA showed that knockdown of Prdx1 inhibited HBV RNA decay, suggesting that Prdx1 reduces HBV RNA levels posttranscriptionally. The RNA coimmunoprecipitation assay revealed that Prdx1 interacted with HBV RNA. The exosome component 5 (Exosc5), a member of the RNA exosome complexes, was coimmunoprecipitated with Prdx1, suggesting its role in regulation of HBV RNA stability. Taken together, these results suggest that Prdx1 and Exosc5 play crucial roles in host defense mechanisms against HBV infection.IMPORTANCE Hepatitis B virus (HBV) infection is a major global health problem. HBx plays important roles in HBV replication and viral carcinogenesis through its interaction with host factors. In this study, we identified Prdx1 as a novel HBx-binding protein. We provide evidence suggesting that Prdx1 promotes HBV RNA decay through interaction with HBV RNA and Exosc5, leading to downregulation of HBV RNA. These results suggest that Prdx1 negatively regulates HBV propagation. Our findings may shed new light on the roles of Prdx1 and Exosc5 in host defense mechanisms in HBV infection.


Assuntos
Antígenos de Neoplasias/metabolismo , Complexo Multienzimático de Ribonucleases do Exossomo/metabolismo , Exossomos/metabolismo , Vírus da Hepatite B/genética , Hepatite B/metabolismo , Hepatite B/virologia , Peroxirredoxinas/metabolismo , RNA Viral/genética , Proteínas de Ligação a RNA/metabolismo , Transativadores/metabolismo , Linhagem Celular Tumoral , Elementos Facilitadores Genéticos/genética , Células Hep G2 , Interações Hospedeiro-Patógeno/fisiologia , Humanos , Imunoprecipitação/métodos , Cinética , Regiões Promotoras Genéticas/genética , Proteínas Virais Reguladoras e Acessórias , Replicação Viral/genética
10.
Hepatol Res ; 50(3): 283-291, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31756766

RESUMO

AIM: Interferon (IFN)-λ3 is known to have antiviral effects against various pathogens. Recently, it has been reported that the production of IFN-λ3 in colon cells after the administration of nucleotide analogs is expected to reduce hepatitis B surface antigen in chronic hepatitis B patients. Here, we aimed to prove the antiviral effects of IFN-λ3 on hepatitis B virus (HBV) by using an in vitro HBV production and infection system. METHODS: We used HepG2.2.15-derived HBV as an inoculum and the replication-competent molecular clone of HBV as a replication model. RESULTS: By administering IFN-λ3 to HepG2 cells transfected with the HBV molecular clone, the production of hepatitis B surface antigen and hepatitis B core-related antigen was reduced dose-dependently. IFN-λ3 treatment also reduced the number of HBV-positive cells and the synthesis of covalently closed circular DNA after infection of HepG2.2.15-derived HBV to sodium taurocholate cotransporting polypeptide-transduced HepG2 cells. The inhibitory effect on HBV infection by IFN-λ3 was confirmed by using a recombinant a HBV reporter virus system. To elucidate the underlying mechanisms of the anti-HBV effect of IFN-λ3, we assessed the transcription of HBV RNA and the production of core-associated HBV DNA in HBV molecular clone-transfected HepG2 cells, and found that both parameters were reduced by IFN-λ3. CONCLUSIONS: We observed that the administration of IFN-λ3 inhibits HBV infection and the production of HBV proteins at the HBV RNA transcription level. This finding provides novel insight into the treatment of chronic hepatitis B patients with the administration or induction of IFN-λ3.

11.
Biochem Biophys Res Commun ; 503(3): 1854-1860, 2018 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-30055801

RESUMO

Hepatitis B virus (HBV) -x protein is a transcriptional regulator required for the HBV life cycle. HBx also induces complications in the host such as hepatocellular carcinoma. We previously showed that HBx mRNA is degraded by the Ski2/RNA exosome complex. In the present study, we report the regulation of this system through the control of Ski2 expression. We identified interleukin (IL) -1ß as an inducer of expression from the Ski2 promoter. IL-1ß induced the expression of ATF3 transcription factor, which in turn binds to cyclic AMP-responsive element sequence in the Ski2 promoter and is responsible for Ski2 promoter induction by IL-1ß. We previously reported that Ski2 expression increases HBx mRNA degradation; consistent with those data, we showed here that HBx mRNA is degraded in response to IL-1ß treatment. Interestingly, HBx also significantly induced Ski2 expression. To our knowledge, this is the first report to show activation of the Ski2/RNA exosome complex by both the host and HBV. Understanding the regulation of the Ski2/RNA exosome system is expected to facilitate prevention of HBx-mediated complications through targeting the posttranscriptional degradation of HBx mRNA; and will also help shedding a light on the role of RNA decay systems in inflammation.


Assuntos
Fator 3 Ativador da Transcrição/metabolismo , Complexo Multienzimático de Ribonucleases do Exossomo/genética , Interleucina-1beta/metabolismo , RNA Mensageiro/metabolismo , Transativadores/metabolismo , Animais , Células Cultivadas , Complexo Multienzimático de Ribonucleases do Exossomo/metabolismo , Células Hep G2 , Humanos , Camundongos , Camundongos SCID , Camundongos Transgênicos , RNA Mensageiro/genética , Transativadores/genética , Proteínas Virais Reguladoras e Acessórias
12.
J Biol Chem ; 291(31): 15958-74, 2016 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-27281821

RESUMO

Hepatitis B virus (HBV) is a stealth virus, minimally inducing the interferon system required for efficient induction of both innate and adaptive immune responses. However, 90% of acutely infected adults can clear the virus, suggesting the presence of other, interferon-independent pathways leading to viral clearance. Given the known ability of helicases to bind viral nucleic acids, we performed a functional screening assay to identify helicases that regulate HBV replication. We identified the superkiller viralicidic activity 2-like (SKIV2L) RNA helicase (a homolog of the Saccharomyces cerevisiae Ski2 protein) on the basis of its direct and preferential interaction with HBV X-mRNA. This interaction was essential for HBV X-mRNA degradation at the RNA exosome. The degradation of HBV X-mRNA at the RNA exosome was also mediated by HBS1L (HBS1-like translational GTPase) protein, a known component of the host RNA quality control system. We found that the redundant HBV-precore translation initiation site present at the 3'-end of HBV X-mRNA (3' precore) is translationally active. The initiation of translation from this site without a proper stop codon was identified by the non-stop-mediated RNA decay mechanism leading to its degradation. Although 3' precore is present in the five main HBV-RNA transcripts, only X-mRNA lacks the presence of an upstream start codons for large, middle, and small (L, M, and S) HBV surface proteins. These upstream codons are in-frame with 3' precore translation initiation site, blocking its translation from the other HBV-mRNA transcripts. To our knowledge, this is the first demonstration of the anti-viral function of the non-stop-mediated RNA decay mechanism.


Assuntos
Complexo Multienzimático de Ribonucleases do Exossomo/metabolismo , Vírus da Hepatite B/metabolismo , Estabilidade de RNA , RNA Mensageiro/metabolismo , RNA Viral/metabolismo , Transativadores/biossíntese , Códon de Iniciação/genética , Códon de Iniciação/metabolismo , DNA Helicases/genética , DNA Helicases/metabolismo , Complexo Multienzimático de Ribonucleases do Exossomo/genética , Células Hep G2 , Vírus da Hepatite B/genética , Humanos , RNA Mensageiro/genética , RNA Viral/genética , Transativadores/genética , Proteínas Virais Reguladoras e Acessórias
13.
Gastroenterology ; 145(3): 658-67.e11, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23684750

RESUMO

BACKGROUND & AIMS: A 3-dimensional (3D) culture system for immortalized human hepatocytes (HuS-E/2 cells) recently was shown to support the lifecycle of blood-borne hepatitis C virus (HCV). We used this system to identify proteins that are active during the HCV lifecycle under 3D culture conditions. METHODS: We compared gene expression profiles of HuS-E/2 cells cultured under 2-dimensional and 3D conditions. We identified signaling pathways that were activated differentially in the cells, and analyzed their functions in the HCV lifecycle using a recombinant HCV-producing cell-culture system, with small interfering RNAs and chemical reagents. We investigated the effects of anti-HCV reagents that altered these signaling pathways in mice with humanized livers (carrying human hepatocytes). RESULTS: Microarray analysis showed that cells cultured under 2-dimensional vs 3D conditions expressed different levels of messenger RNAs encoding prostaglandin synthases. Small interfering RNA-mediated knockdown of thromboxane A2 synthase (TXAS) and incubation of hepatocytes with a TXAS inhibitor showed that this enzyme is required for production of infectious HCV, but does not affect replication of the HCV genome or particle release. The TXAS inhibitor and a prostaglandin I2 receptor agonist, which has effects that are opposite those of thromboxane A2, reduced serum levels of HCV and inhibited the infection of human hepatocytes by blood-borne HCV in mice. CONCLUSIONS: An inhibitor of the prostaglandin synthase TXAS inhibits production of infectious HCV particles in cultured hepatocytes and HCV infection of hepatocytes in mice with humanized livers. It therefore might be therapeutic for HCV infection.


Assuntos
Inibidores Enzimáticos/uso terapêutico , Hepacivirus/enzimologia , Hepatite C/prevenção & controle , Hepatócitos/virologia , Metacrilatos/uso terapêutico , Tromboxano-A Sintase/antagonistas & inibidores , Proteínas Virais/antagonistas & inibidores , Animais , Sequência de Bases , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Células Cultivadas , Inibidores Enzimáticos/farmacologia , Técnica Indireta de Fluorescência para Anticorpo , Hepacivirus/efeitos dos fármacos , Hepacivirus/patogenicidade , Hepatite C/virologia , Humanos , Metacrilatos/farmacologia , Camundongos , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tromboxano-A Sintase/metabolismo , Proteínas Virais/metabolismo
14.
Biochem Biophys Res Commun ; 443(3): 808-13, 2014 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-24342612

RESUMO

Hepatitis B virus (HBV) entry has been analyzed using infection-susceptible cells, including primary human hepatocytes, primary tupaia hepatocytes, and HepaRG cells. Recently, the sodium taurocholate cotransporting polypeptide (NTCP) membrane transporter was reported as an HBV entry receptor. In this study, we established a strain of HepG2 cells engineered to overexpress the human NTCP gene (HepG2-hNTCP-C4 cells). HepG2-hNTCP-C4 cells were shown to be susceptible to infection by blood-borne and cell culture-derived HBV. HBV infection was facilitated by pretreating cells with 3% dimethyl sulfoxide permitting nearly 50% of the cells to be infected with HBV. Knockdown analysis suggested that HBV infection of HepG2-hNTCP-C4 cells was mediated by NTCP. HBV infection was blocked by an anti-HBV surface protein neutralizing antibody, by compounds known to inhibit NTCP transporter activity, and by cyclosporin A and its derivatives. The infection assay suggested that cyclosporin B was a more potent inhibitor of HBV entry than was cyclosporin A. Further chemical screening identified oxysterols, oxidized derivatives of cholesterol, as inhibitors of HBV infection. Thus, the HepG2-hNTCP-C4 cell line established in this study is a useful tool for the identification of inhibitors of HBV infection as well as for the analysis of the molecular mechanisms of HBV infection.


Assuntos
Vírus da Hepatite B/fisiologia , Transportadores de Ânions Orgânicos Dependentes de Sódio/metabolismo , Simportadores/metabolismo , Internalização do Vírus , Animais , Dimetil Sulfóxido/farmacologia , Células Hep G2 , Hepatite B/patologia , Hepatite B/virologia , Vírus da Hepatite B/efeitos dos fármacos , Humanos , Transportadores de Ânions Orgânicos Dependentes de Sódio/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Simportadores/genética , Tupaia , Internalização do Vírus/efeitos dos fármacos
15.
J Urol ; 191(5): 1370-4, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24262496

RESUMO

PURPOSE: We compared slow vs fast shock wave frequency rates in disintegration of pediatric renal stones less than 20 mm. MATERIALS AND METHODS: Our study included 60 children with solitary 10 to 20 mm radiopaque renal stones treated with shock wave lithotripsy. Patients were prospectively randomized into 2 groups, ie those undergoing lithotripsy at a rate of 80 shock waves per minute (group 1, 30 patients) and those undergoing lithotripsy at a rate of 120 shock waves per minute (group 2, 30 patients). The 2 groups were compared in terms of treatment success, anesthesia time, secondary procedures and efficiency quotient. RESULTS: Stone clearance rate was significantly higher in group 1 (90%) than in group 2 (73.3%, p = 0.025). A total of 18 patients in group 1 (60%) were rendered stone-free after 1 session, 8 required 2 sessions and 1 needed 3 sessions, while shock wave lithotripsy failed in 3 patients. By comparison, 8 patients (26.6%) in group 2 were rendered stone-free after 1 session, 10 (33.3%) required 2 sessions and 4 (13.3%) needed 3 sessions to become stone-free. Mean general anesthesia time was significantly longer in group 1 (p = 0.041). Postoperatively 2 patients in group 1 and 4 in group 2 suffered low grade fever (Clavien grade II). Significantly more secondary procedures (percutaneous nephrolithotomy, repeat shock wave lithotripsy) were required in group 2 (p = 0.005). The predominant stone analysis was calcium oxalate dihydrate in both groups. Efficiency quotient was 0.5869 and 0.3437 for group 1 and group 2, respectively (p = 0.0247). CONCLUSIONS: In children with renal stones slow delivery rates of shock wave lithotripsy have better results regarding stone clearance than fast delivery rates.


Assuntos
Cálculos Renais/terapia , Litotripsia/métodos , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Estudos Prospectivos , Fatores de Tempo
16.
Antiviral Res ; 223: 105821, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38272318

RESUMO

Although antimicrobial peptides have been shown to inactivate viruses through disruption of their viral envelopes, clinical use of such peptides has been hampered by a number of factors, especially their enzymatically unstable structures. To overcome the shortcomings of antimicrobial peptides, peptoids (sequence-specific N-substituted glycine oligomers) mimicking antimicrobial peptides have been developed. We aimed to demonstrate the antiviral effects of antimicrobial peptoids against hepatitis B virus (HBV) in cell culture. The anti-HBV activity of antimicrobial peptoids was screened and evaluated in an infection system involving the HBV reporter virus and HepG2.2.15-derived HBV. By screening with the HBV reporter virus infection system, three (TM1, TM4, and TM19) of 12 peptoids were identified as reducing the infectivity of HBV, though they did not alter the production levels of HBs antigen in cell culture. These peptoids were not cytotoxic at the evaluated concentrations. Among these peptoids, TM19 was confirmed to reduce HBV infection most potently in a HepG2.2.15-derived HBV infection system that closely demonstrates authentic HBV infection. In cell culture, the most effective administration of TM19 was virus treatment at the infection step, but the reduction in HBV infectivity by pre-treatment or post-treatment of cells with TM19 was minimal. The disrupting effect of TM19 targeting infectious viral particles was clarified in iodixanol density gradient analysis. In conclusion, the peptoid TM19 was identified as a potent inhibitor of HBV. This peptoid prevents HBV infection by disrupting viral particles and is a candidate for a new class of anti-HBV reagents.


Assuntos
Anti-Infecciosos , Hepatite B , Peptoides , Humanos , Vírus da Hepatite B , Peptoides/farmacologia , Peptoides/química , Hepatite B/tratamento farmacológico , Técnicas de Cultura de Células , Antivirais/farmacologia , Peptídeos Antimicrobianos
17.
Viruses ; 15(1)2023 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-36680254

RESUMO

Vaccination has been confirmed to be the safest and, sometimes, the only tool of defense against threats from infectious diseases. The successful history of vaccination is evident in the control of serious viral infections, such as smallpox and polio. Viruses that infect human livers are known as hepatitis viruses and are classified into five major types from A to E, alphabetically. Although infection with hepatitis A virus (HAV) is known to be self-resolving after rest and symptomatic treatment, there were 7134 deaths from HAV worldwide in 2016. In 2019, hepatitis B virus (HBV) and hepatitis C virus (HCV) resulted in an estimated 820,000 and 290,000 deaths, respectively. Hepatitis delta virus (HDV) is a satellite virus that depends on HBV for producing its infectious particles in order to spread. The combination of HDV and HBV infection is considered the most severe form of chronic viral hepatitis. Hepatitis E virus (HEV) is another orally transmitted virus, common in low- and middle-income countries. In 2015, it caused 44,000 deaths worldwide. Safe and effective vaccines are already available to prevent hepatitis A and B. Here, we review the recent advances in protective vaccines against the five major hepatitis viruses.


Assuntos
Vírus da Hepatite A , Hepatite A , Hepatite B , Hepatite C , Vacinas , Humanos , Vírus de Hepatite , Hepatite B/prevenção & controle , Vírus da Hepatite B , Vírus Delta da Hepatite
18.
Diabetes Res Clin Pract ; 200: 110670, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37169307

RESUMO

AIM: Cardiac autonomic neuropathy (CAN) has been suggested to be associated with hypoglycemia and impaired hypoglycemia unawareness. We have assessed the relationship between CAN and extensive measures of glucose variability (GV) in patients with type 1 and type 2 diabetes. METHODS: Participants with diabetes underwent continuous glucose monitoring (CGM) to obtain measures of GV and the extent of hyperglycemia and hypoglycemia and cardiovascular autonomic reflex testing. RESULTS: Of the 40 participants (20 T1DM and 20 T2DM) (aged 40.70 ± 13.73 years, diabetes duration 14.43 ± 7.35 years, HbA1c 8.85 ± 1.70%), 23 (57.5%) had CAN. Despite a lower coefficient of variation (CV) (31.26 ± 11.87 vs. 40.33 ± 11.03, P = 0.018), they had a higher CONGA (8.42 ± 2.58 vs. 6.68 ± 1.88, P = 0.024) with a lower median LBGI (1.60 (range: 0.20-3.50) vs. 4.90 (range: 3.20-7.40), P = 0.010) and percentage median time spent in hypoglycemia (4 (range:4-13) vs. 1 (range:0-5), P = 0.008), compared to those without CAN. The percentage GRADEEuglycemia (3.30 ± 2.78 vs. 5.69 ± 3.09, P = 0.017) and GRADEHypoglycemia (0.3 (range: 0 - 3.80) vs. 1.8 (range: 0.9-6.5), P = 0.036) were significantly lower, while the percentage median GRADEHyperglycemia (95.45 (range:93-98) vs. 91.6 (82.8-95.1), P = 0.013) was significantly higher in participants with CAN compared to those without CAN. CONCLUSION: CAN was associated with increased glycemic variability with less time in euglycemia attributed to a greater time in hyperglycemia but not hypoglycemia.


Assuntos
Diabetes Mellitus Tipo 2 , Hiperglicemia , Hipoglicemia , Humanos , Diabetes Mellitus Tipo 2/complicações , Glicemia , Automonitorização da Glicemia , Hemoglobinas Glicadas , Hipoglicemia/complicações , Hiperglicemia/complicações , Glucose , Hipoglicemiantes
19.
Microbiol Immunol ; 56(1): 1-9, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22145950

RESUMO

Chronic hepatitis C virus (HCV) infection affects approximately 170 million people worldwide. HCV infection is a major global health problem as it can be complicated with liver cirrhosis and hepatocellular carcinoma. So far, there is no vaccine available and the non-specific, interferon (IFN)-based treatments now in use have significant side-effects and are frequently ineffective, as only approximately 50% of treated patients with genotypes 1 and 4 demonstrate HCV clearance. The lack of suitable in vitro and in vivo models for the analysis of HCV infection has hampered elucidation of the HCV life cycle and the development of both protective and therapeutic strategies against HCV infection. The present review focuses on the progress made towards the establishment of such models.


Assuntos
Técnicas de Cultura de Células/métodos , Genoma Viral , Hepacivirus/fisiologia , RNA Viral/genética , Animais , Linhagem Celular , Hepacivirus/genética , Hepacivirus/imunologia , Hepatite C/imunologia , Hepatite C/virologia , Hepatócitos/virologia , Humanos , Interferons/imunologia , Camundongos , RNA Viral/imunologia , Soro/virologia , Cultura de Vírus/métodos , Replicação Viral
20.
Front Bioeng Biotechnol ; 10: 876672, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35646863

RESUMO

Diabetes mellitus is characterized by elevated blood glucose levels, however patients with diabetes may also develop hypoglycemia due to treatment. There is an increasing demand for non-invasive blood glucose monitoring and trends detection amongst people with diabetes and healthy individuals, especially athletes. Wearable devices and non-invasive sensors for blood glucose monitoring have witnessed considerable advances. This review is an update on recent contributions utilizing novel sensing technologies over the past five years which include electrocardiogram, electromagnetic, bioimpedance, photoplethysmography, and acceleration measures as well as bodily fluid glucose sensors to monitor glucose and trend detection. We also review methods that use machine learning algorithms to predict blood glucose trends, especially for high risk events such as hypoglycemia. Convolutional and recurrent neural networks, support vector machines, and decision trees are examples of such machine learning algorithms. Finally, we address the key limitations and challenges of these studies and provide recommendations for future work.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA