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El virus SARS-CoV-2 sigue replicándose. Sus nuevas variantes no estarían causando las muertes y hospitalizaciones graves de los años 2020 a 2022, por lo que la Organización Mundial de la Salud (OMS) ha declarado el final del estado de emergencia sanitaria. Hasta el 24 de mayo de 2023, el tablero de coronavirus de la OMS señala más de 766 millones de casos confirmados, y cerca de 7 millones de muertes en el mundo, con mayor concentración en Europa, Pacífico Occidental y América (especialmente en los E.E. U.U. y Brasil). Europa y China se preparan para los nuevos avances del virus. Por ello se recomienda precaución sanitaria y cumplir con la vacunación y refuerzos, así como elaborar nuevas vacunas. Se comenta sobre la fragilidad de los ensayos aleatorios publicados en los primeros dos años de la pandemia, así como los recientes hallazgos de cuáles enfermos con COVID podrían desarrollar COVID prolongado. Es de importancia conocer los nuevos alcances sobre la afectación del coronavirus sobre la gestante, el feto y neonato y el seguimiento inicial de los últimos.
The SARS-CoV-2 virus continues to replicate. Its new variants would not be causing the deaths and serious hospitalizations of the years 2020-2022, so the World Health Organization (WHO) has declared the end of the state of health emergency. Until May 24, 2023, the WHO coronavirus dashboard shows more than 766 million confirmed cases, and about 7 million deaths in the world, with greater concentration in Europe, Western Pacific, and America (especially the U.S.A. and Brazil). Europe and China prepare for new virus breakthroughs. Therefore, health precaution is recommended, as well as compliance with vaccination and boosters, and the development of new vaccines. We comment on the fragility of randomized trials published in the first two years of the pandemic, as well as recent findings of which patients with COVID could develop long COVID. It is important to know the new scopes on the affectation of the coronavirus on the pregnant woman, the fetus and the neonate and the initial follow-up of the latter.
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Objective:To observe the effects of sacubitril/valsartan (LCZ696) on viral replication and cardiomyocyte apoptosis in mice with coxsackievirus B3 (CVB3)-induced viral myocarditis (VMC) and to analyze the underlying mechanisms.Methods:Forty BALB/c mice were randomly divided into four groups with 10 in each group: Sham, Sham+ LCZ696, VMC, and VMC+ LCZ696 groups. VMC model was established by intraperitoneal injection of 0.1 ml of CVB3 with a concentration of 10 6 TCID 50/ml into BALB/c mice, while the sham intervention was an equal volume of saline. The day of virus injection was defined as day 0. LCZ696 was administered by gavage at a dose of 60 mg/kg every day for seven consecutive days starting from day 1. Mouse survival rates were calculated. Echocardiography was used to evaluate the cardiac function of mice. The level of creatine kinase-MB (CK-MB) was detected by ELISA. Western blot was used to detect the levels of inflammatory cytokines (IL-6, TNF-α), apoptosis-related proteins (caspase-3, cleaved-caspase-3, Bax, Bcl-2), CVB3 surface protein (VP-1) and p-AKT/AKT in the hearts of mice. CVB3 mRNA in mouse hearts was measured by PCR. Inflammatory cell infiltration and cell apoptosis in mouse hearts were observed by HE staining and TUNEL staining, respectively. Results:Compared with the Sham group, the mice in the VMC group had a decreased survival rate and impaired cardiac function ( P<0.05). The levels of CK-MB, IL-6, TNF-α, cleaved-caspase-3/caspase-3, Bax/Bcl-2, VP-1, and CVB3 mRNA in the hearts of VMC mice increased significantly ( P<0.05), accompanied by increased expression of AKT, decreased phosphorylation of AKT ( P<0.05) and increased cell apoptosis. LCZ696 reversed the above changes. It could increase the survival rate, improve the cardiac function ( P<0.05), decrease cardiac inflammation, cell apoptosis and viral replication ( P<0.05), and increase the phosphorylation of AKT ( P<0.05). LCZ696 had no significant effects on the survival rate, cardiac function, myocardial injury, cardiac inflammation, cell apoptosis, viral replication or the expression of PI3K/AKT signaling pathway-related proteins in normal mice. Conclusions:LCZ696 could significantly inhibit cardiomyocyte apoptosis and reduce CVB3 replication in the hearts of VMC mice by regulating the PI3K/AKT pathway, thereby improving mouse cardiac function and survival rate.
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Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has become one major threat to human population health. The RNA-dependent RNA polymerase (RdRp) presents an ideal target of antivirals, whereas nucleoside analogs inhibitor is hindered by the proofreading activity of coronavirus. Herein, we report that corilagin (RAI-S-37) as a non-nucleoside inhibitor of SARS-CoV-2 RdRp, binds directly to RdRp, effectively inhibits the polymerase activity in both cell-free and cell-based assays, fully resists the proofreading activity and potently inhibits SARS-CoV-2 infection with a low 50% effective concentration (EC
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Objective@#To investigate the relationship between enterovirus 71 (EV71) and autophagy and the effect of autophagy on viral replication.@*Methods@#RD cells were pretreated with rapamycin, Chloroquine (CQ) and 3-methyladenine (3-MA). The effects of different stages of autophagy on viral replication were detected by Western blotting and plaque assay.@*Results@#The study showed that EV71 infection could induce incomplete autophagy in RD cells. Replication of EV71 was promoted in the CQ treatment group, while the level of replication of the rapamycin and 3-MA treatment groups was reduced. Further studies have shown that mTOR is a key molecule affecting EV71 replication, and inhibition of mTOR by rapamycin can inhibit the synthesis of viral RNA.@*Conclusions@#The effects of different stages of autophagy on viral replication are also different. Inhibition of autophagic lysosome degradation promotes viral replication, while inhibition of the early stage of autophagy or promotion of autophagy reduces the level of viral replication. mTOR can affect the replication of EV71 at RNA level.
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ABSTRACT Dengue, the most prevalent arboviral disease worldwide, is caused by any of the four dengue virus (DENV) serotypes that co-circulate constantly in hyperendemic areas such as Medellin (Colombia), and these serotypes are transmitted by mosquitoes of the genus Aedes. In this study, we evaluated the replicative capacity of strains isolated in Medellin between 2003 and 2007 in C6/36 cells and in colonies of Aedes aegypti collected during 2010-2011 from high or low-incidence areas within the same city. The phylogenetic analysis grouped isolates according to the predominant genotypes found in the Americas, and the in vitro characterization showed differences in the morphological changes induced by the isolates of each of the isolated serotypes compared to the reference serotypes. In vitro replicative capacity studies demonstrated that genomic copy number increased at four days post-infection and that cell viability decreased significantly compared to the control for all serotypes. The largest number of genomic copies in C6/36 was produced by DENV-2, followed by DENV-1 and DENV-4; DENV-3 produced the smallest number of genomic copies and had the smallest negative effect on cell viability. Finally, differences in the in vivo replication of intercolonial serotypes between the Rockefeller colony and the field colonies and among the intracolonial serotypes were found. The replication of DENV-2 at 7 and 14 days in both high- and low-incidence colonies was higher than that of the other serotypes, and replication of DENV-3 in the mosquito colonies was the most stable on the days evaluated. Our results support the notion that replication and, possibly, DENV transmission and severity depend on many factors, including serotype and vector characteristics.
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Humanos , Animales , Replicación Viral , Aedes/virología , Dengue/transmisión , Virus del Dengue/fisiología , Insectos Vectores/virología , Filogenia , Población Urbana , Colombia , Dengue/virología , Virus del Dengue/aislamiento & purificación , Virus del Dengue/genética , SerogrupoRESUMEN
Objetivo: evaluar el desempeño clínico de un método de reacción en cadena de la polimerasa con modificaciones para la detección de la replicación del virus de la hepatitis B en pacientes infectados. Métodos: se estudiaron 266 muestras de suero de pacientes provenientes de los servicios de Gastroenterología, Trasplante, Hemodiálisis y Hematología del Hospital Clínicoquirúrgico Hermanos Ameijeiras, con el antígeno de superficie (HBsAg) positivo y altos valores de enzimas hepáticas (aspartatoaminotransferasa, aspartatoaminotransglutaminasa y ganmaglutamiltrasferasa), así como 5 muestras de individuos clínicamente sanos. El ADN se extrajo mediante el método del fenol-cloroformo. Se amplificó un fragmento de la región Pre S del virus de la hepatitis B y un fragmento del gen de la ß-globina como control interno de la reacción. Resultados: El fragmento del gen de la ß-globina se verificó en las 266 muestras estudiadas. La región Pre S del virus de la hepatitis B en cambio, fue detectada en 103 de ellas, siendo informadas como positivas para la replicación viral. En la muestra se obtuvo una prevalencia 98,15 por ciento para la replicación del virus de la hepatitis B. La especificidad clínica del ensayo fue del 100 por ciento, la sensibilidad clínica del 38 por ciento, el valor predictivo positivo del 100 por ciento y el valor predictivo negativo del 64 por ciento. El análisis de concordancia no mostró acuerdo (κ= 0,022 para una p= 0,07) entre las enzimas hepáticas y la reacción en cadena de la polimerasa. Los ensayos de repetitividad y de reproducibilidad mostraron que los resultados son reproducibles. El mayor porcentaje de positividad se encontró en los pacientes remitidos por el Servicio de Hematología (66,7 por ciento). Conclusiones: el método de reacción en cadena de la polimerasa evaluado constituye una herramienta certera para el monitoreo de la replicación del virus de la hepatitis B. Contar con su implementación y aplicación en la institución que se efectuó el estudio reviste gran importancia para el sistema de salud del país(AU)
Objective: evaluate the clinical performance of a modified polymerase chain reaction method to detect replication of the hepatitis B virus in infected patients. Methods: a study was conducted of 266 serum samples from patients cared for at gastroenterology, transplantation, hemodialysis and hematology services of Hermanos Ameijeiras Clinical Surgical Hospital with positive surface antigen HBsAg and high liver enzyme values (aspartate aminotransferase, aspartate aminotransglutaminase and gamma-glutamyltransferase), and 5 samples from clinically healthy individuals. The DNA was extracted by the phenol-chloroform method. Amplification was performed of a fragment of the Pre S region of the hepatitis B virus and a fragment of the ß-globin gene as internal control of the reaction. Results: the ß-globin gene fragment was found in the 266 samples studied. The Pre S region of the hepatitis B virus, however, was detected in 103 of them. These were reported as positive for viral replication. The sample exhibited a prevalence of 98.15 percent for replication of the hepatitis B virus. Clinical specificity of the assay was 100 percent, clinical sensitivity was 38 percent, positive predictive value was 100 percent and negative predictive value was 64 percent. Concordance analysis did not reveal any agreement (κ= 0.022 for p= 0.07) between the liver enzymes and the polymerase chain reaction. Repeatability and reproducibility assays showed that the results are reproducible. The highest positivity percentage was found in patients referred from the Hematology Service (66.7 percent). Conclusions: the polymerase chain reaction method evaluated is an accurate tool to monitor replication of the hepatitis B virus. The possibility of its implementation and application at the institution where the study was conducted is very important for the Cuban health system(AU)
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Humanos , Replicación Viral , Reacción en Cadena de la Polimerasa/métodos , Hepacivirus/fisiología , Hepatitis B , Epidemiología Descriptiva , Estudios TransversalesRESUMEN
Norovirus (NoV), a single stranded RNA virus, is the major causative agent of the global acute gastroenteritis in humans, and it has drawn more and more attention. Because of the lack of appropriate animal models and in vitro cell culture models, people have studied and understood more about the epidemiology and genetic variation of human viruses. The functional characteristics of the viral encoded protein and the pathogenesis of virus infection are poorly understood. In this paper, we summarize the progress in studies on characteristics of non-structural protein of norovirus, and hope that with the recent breakthrough in human cell culture model of human norovirus, it can be used as a tool for further research on the function of human norovirus non-structural protein.
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BACKGROUND/AIMS: According to the results of several studies, the outcome of hepatitis C virus (HCV) reactivation is not as severe as the outcome of hepatitis B virus reactivation. The aim of this study was to evaluate the effect of pharmacological immunosuppression on HCV reactivation. METHODS: The medical records of patients who underwent systemic chemotherapy, corticosteroid therapy, or other immunosuppressive therapies between January 2008 and March 2015 were reviewed. Subsequently, 202 patients who were seropositive for the anti-HCV antibody were enrolled. Exclusion criteria were: unavailability of data on HCV RNA levels, a history of treatment for chronic hepatitis C, and the presence of liver diseases other than a chronic HCV infection. RESULTS: Among the 120 patients enrolled in this study, hepatitis was present in 46 patients (38%). None of the patients were diagnosed with severe hepatitis. Enhanced replication of HCV was noted in nine (27%) of the 33 patients who had data available on both basal and follow-up HCV RNA loads. Reappearance of the HCV RNA from an undetectable state did not occur after treatment. The cumulative rate of enhanced HCV replication was 23% at 1 year and 30% at 2 years. CONCLUSIONS: Although enhanced HCV replication is relatively common in HCV-infected patients treated with chemotherapy or immunosuppressive therapy, it does not lead to serious sequelae.
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Humanos , Quimioterapia , Estudios de Seguimiento , Hepacivirus , Virus de la Hepatitis B , Hepatitis C , Hepatitis C Crónica , Hepatitis , Terapia de Inmunosupresión , Hepatopatías , Registros Médicos , ARNRESUMEN
Twelve nucleotides located at the 3′ end of viral genomic RNA (vRNA) are conserved among influenza A viruses (IAV) and have a promoter function. Hoffmann's 8-plasmid reverse genetics vector system introduced mutations at position 4, C nucleotide (C4) to U nucleotide (U4), of the 3′ ends of neuraminidase (NA) and matrix (M) vRNAs of wild-type A/PR/8/34 (PR8). This resulted in a constellation of C4 and U4 vRNAs coding for low (polymerases) and relatively high (all others) copy number proteins, respectively. U4 has been reported to increase promoter activity in comparison to C4, but the constellation effect on the replication efficiency and pathogenicity of reverse genetics PR8 (rgPR8) has not been fully elucidated. In the present study, we generated 3 recombinant viruses with C4 in the NA and/or M vRNAs and rgPR8 by using reverse genetics and compared their pathobiological traits. The mutant viruses showed lower replication efficiency than rgPR8 due to the low transcription levels of NA and/or M genes. Furthermore, C4 in the NA and/or M vRNAs induced lower PR8 virus pathogenicity in BALB/c mice. The results suggest that the constellation of C4 and U4 among vRNAs may be one of the multigenic determinants of IAV pathogenicity.
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Animales , Ratones , Codificación Clínica , Virus de la Influenza A , Gripe Humana , Neuraminidasa , Nucleótidos , Orthomyxoviridae , Genética Inversa , ARN , VirulenciaRESUMEN
Resumen El virus chikungunya pertenece al género Alphavirus, de la familia de los Togaviridae. Es transmitido por artrópodos, en particular por la picada de especies de mosquitos, tales como Aedes aegypti y Aedes albopictus. El curso clínico característico de la infección incluye fiebres, artralgias y exantema. Desde que fue reportado en 1952 en los límites de Tanzania y Mozambique ha generado brotes de enorme significado epidemiológico. Recientemente fue causado un brote en las Américas por una cepa del virus, aparentemente, asiática. En esta revisión presentamos su filogenia, estructura y organización del genoma. Enfatizaremos en el mecanismo de multiplicación y la expresión genética. Finalmente, la interacción virus-huésped y sus mecanismos de adaptación a vectores específicos también son discutidos.
Abstract Chikungunya virus belongs to the Alphavirus genus of the family Togaviridae. It is transmitted by arthropods, in particular by the biting of mosquito species such as Aedes aegypti and Aedes albopictus. The characteristic clinical course of the infection includes fever, arthralgia, and rash. Since it was reported on 1952 on the borders of Tanzania and Mozambique, it has been triggered outbreaks with tremendous epidemiological significance. Recently an outbreak was caused in the Americas by an apparent Asian strain of this virus. In this review we present its phylogeny, structure and genome organization. We will emphasize the mechanism of replication and gene expression. Finally, the virus-host interaction and its mechanisms of adaptation to specific vectors are also discussed.
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Los mecanismos innatos antivirales han resultado de gran interés debido a su uso potencial para la prevención y tratamiento de la infección por el VIH. En particular, los factores solubles antivirales han sido objeto de múltiples investigaciones por su capacidad de inhibir diferentes pasos del ciclo replicativo viral y de potenciar la respuesta inmune del hospedero. Entre estos factores solubles se destacan TRIM-5α, APOBEC3G, SAMHD1, ELAFIN, SERPINA1 y SLPI, que actúan directamente sobre la partícula viral o la célula, o promueven la producción de moléculas involucradas en la respuesta inmune contra el virus. Algunos de ellos se han correlacionado con un bajo riesgo de adquirir la infección por el VIH o con una lenta progresión a sida. La exploración de los mecanismos antivirales de estas proteínas es requisito para el desarrollo de nuevas alternativas terapéuticas.
Antiviral innate mechanisms have a potential use in developing preventive and therapeutic strategies against HIV. Specifically, antiviral soluble factors have been evaluated in multiple investigations, based on their capacity to inhibit different steps of the viral cycle, and to increase the host immune response. Among these factors, TRIM-5α, APOBEC3G, SAMHD1, ELAFIN, SERPINA1 and SLPI are of particular interest, as they can act directly on the viral particle or the cell, or promote the production of molecules related to the viral immune response. Some of these factors have been associated with a low risk of HIV infection or slow progression to AIDS. Evaluation of mechanisms exhibited by antiviral proteins is a requirement for developing new therapeutic alternatives.
Os mecanismos inatos antivirais resultaram de grande interesse devido a seu uso potencial para a prevenção e tratamento da infecção pelo HIV. Em particular, os fatores solúveis antivirais foram objeto de múltiplas pesquisas por sua capacidade de inibir diferentes passos do ciclo replicativo viral e de potenciar a resposta imune do hospedeiro. Entre estes fatores solúveis se destacam TRIM-5α, APOBEC3G, SAMHD1, ELAFIN, SERPINA1 e SLPI, que atuam diretamente sobre a partícula viral ou a célula, ou promovem a produção de moléculas envolvidas na resposta imune contra o vírus. Alguns deles se correlacionaram com um baixo risco de adquirir a infecção pelo HIV ou com uma lenta progressão a aids. A exploração dos mecanismos antivirais destas proteínas é requisito para o desenvolvimento de novas alternativas terapêuticas.
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Humanos , Antivirales , Síndrome de Inmunodeficiencia Adquirida , VIH-1 , TerapéuticaRESUMEN
Hepatits B virus( HBV) infection is a global epidemic which seriously harms the public health. In spite of the great progress in hepatits B prevention and treatment, there is few ef-fective medicine. Research findings show that liver damage and degree of liver failure are sophisticatedly related to the interaction between HBV and the immune response of host. All these make it important to know the replication mechanism and the contrac-tion process, in order to lay a preliminary solid foundation for studying HBV drug targets and making a new ant-virus strategy. This article aims to summarize HBV viral replication process, while focusing on the latest research findings about drug targets, to find a new kind of anti-HBV drugs, and to explore the under-lying mechanism of effective drugs.
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Objective: To investigate the effects of p21/Waf1 gene silencing on replicative potential of bladder cancer-specific oncolytic adenovirus and the proliferation inhibition of EJ cells. Methods: The shRNA targeting p21/Waf1 gene (p21/Waf1-shNA) was designed and synthesized, then the annealing oligonucleotide fragments were subcloned into pMagic 7.1 vector containing coding gene of green fluorescent protein (GFP) to construct recombinant lentiviral plasmid pLVT1051, which was confirmed by PCR and DNA sequencing. The 293T cells were co-transfected with three plasmids including pLVT1051, pCMV-VSV-G and pCMV-dR8.91 to produce the recombinant lentivirus. The EJ cells were infected with recombinant lentivirus carrying p21/Waf1-shRNA, and the puromycin was used to screen out the stably infected EJ cells. The expression levels of p21/Waf1 mRNA and protein in EJ cells after infection with recombinant lentivirus carrying p21/Waf1-shRNA were detected by real-time fluorescent quantitative-PCR and Western blotting, respectively. The p21/Waf1 gene-silenced EJ cells were infected with bladder cancer-specific oncolytic adenovirus Ad/PSCAE/UPII/E1A, then the expression levels of virus replication-related proteins E1A and Hexon were detected by Western blotting, and the cytotoxic effect on EJ cells was examined by MTT method. Results: Recombinant lentiviral vector carrying p21/Waf1-shRNA targeting p21/Waf1 gene was successfully established and confirmed by DNA sequencing. The recombinant lentivirus was harvested. The stably infected EJ cells were successfully screened out by using puromycin forr two weeks. The expression levels of p21/Waf1 mRNA and protein in EJ cells infected with recombinant lentivirus carrying p21/Waf1-shRNA were significantly reduced (both P < 0.05). The expression levels of E1A and Hexon proteins in p21/Waf1 gene-silenced EJ cells infected with bladder cancer-specific oncolytic adenovirus Ad/PSCAE/UPII/E1A were up-regulated, and the proliferation inhibition of EJ cells was enhanced (P < 0.01). Conclusion: The p21/Waf1 gene-silenced EJ cells are successfully constructed, and p21/Waf1 gene silencing can enhance the replicative ability of bladder cancer-specific oncolytic adenovirus and significantly inhibit the proliferation of EJ cells.
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O objetivo do trabalho foi avaliar a diminuição da replicação viral (BoHV-1 Colorado) em embriões murinos após tratamento do extrato etanólico da casca de Punica granatum (EEPg). Camundongos fêmeas Swiss com idade entre 6 e 8 semanas foram superovuladas com 0,2 mL a 5 UI de hormônios (eCG e hCG), e acasaladas com machos da mesma idade. Após 18 horas, as fêmeas sofreram eutanásia em câmara de CO2 e, através de abertura no peritônio, os zigotos foram coletados e lavados com solução de pronase 0,5%.Os zigotos foram divididos em quatro grupos: G1 (controle), G2 (expostos aos vírus BoHV-1 Colorado a 108 TCID50/mL), G3 (expostos ao EEPg) e G4 (expostos aos vírus e ao EEPg). Os grupos foram mantidos a 37,5ºC em meio TCM199 (100µL) com 10% de soro fetal bovino em estufa a 5% de CO2 e 95% de umidade. Após 24 h, analisamos a taxa de clivagem (teste exato de Fisher; p<0,05), a morfologia (por microscopia óptica), a nested-PCR e a titulação dos embriões em cocultura com células MDBK após mais 72 h do tratamento (teste de Mann-Whitney; p<0,05) e microscopia eletrônica de transmissão (ME). Os embriões murinos tratados com EEPg apresentaram resultados satisfatórios: sem alterações morfológicas, taxa de clivagem semelhante ao controle e, apesar da detecção da presença do vírus pela nested-PCR e ME, houve diminuição do título viral após tratamentos com esse extrato, o que sugere interferência desse tratamento no ciclo viral do BoHV-1 Colorado sem alterar o desenvolvimento dos embriões.(AU)
The aim of this study was to evaluate the reduction of viral replication (Colorado BoHV-1) in murine embryos after the treatment of ethanol extract of Punica granatum peel (PgEE). Swiss female mice aged 6 to 8 weeks were superovulated with 0.2 mL of the 5 UI hormones (eCG and hCG) and mated with males of the same age. After 18 hours, the females were euthanized in a CO2 chamber, and through the opening in the peritoneum, zygotes were collected and washed with 0.5% pronase solution. The zygotes were divided into four groups: G1 (control), G2 (exposed to the virus Colorado BoHV -1 to 108 TCID50/mL), G3 (exposed to PgEE) and G4 (exposed to the virus and to PgEE). The groups were maintained at 37.5ºC in TCM199 (100 mL) with 10% fetal bovine serum in an incubator at 5% CO2 and 95% humidity. After 24 h, we analyzed the cleavage rate (Fisher's exact test; p<0.05), the morphology (by light microscopy), the nested-PCR and the titration of embryos in co-culture with MDBK cells after over 72 h of treatment (Mann-Whitney test; p<0.05) and transmission electron microscopy (TEM). The murine embryos treated with PgEE showed satisfactory results: no morphological changes, cleavage rate similar to controls, despite the detection of the presence of virus by nested PCR and TEM, there was a decrease of the viral titer after the treatment with this extract, which suggests interference of this treatment in the viral cycle BoHV-1 Colorado without altering the embryo development.(AU)
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Replicación Viral , Muridae , Noxas , Embrión de MamíferosRESUMEN
Estima-se que 170 milhões de pessoas no mundo estejam infectadas com o vírus da hepatite C (VHC), o que está altamente relacionado à ocorrência de hepatite crônica e carcinoma hepatocelular. A prevalência de esteatose hepática em doentes com hepatite C crônica é muito maior do que na população geral variando entre 40 a 75%. A associação entre a infecção pelo VHC e esteatose hepática é multifatorial. Duas formas de esteatose hepática são encontradas em pacientes com hepatite C crônica: esteatose metabólica (fatores de risco) e citopática relacionada ao genótipo 3a. Os lipídios são essenciais para o ciclo de replicação do VHC, eles podem exercer seu efeito em diferentes níveis como: grupos prostéticos em proteínas virais e/ou cofatores celulares na replicação de VHC, componentes especializados na estrutura do VHC onde ocorre a replicação ou como constituinte das partículas lipovirais. Trabalhos experimentais realizados anteriormente por nosso grupo relataram que a administração do composto natural Yo Jyo Hen Shi Ko (YHK) promove a inibição do desenvolvimento da esteatose, redução dos marcadores de estresse oxidativo, menor escore de inflamação, melhora nas concentrações de aminotransferases e diminuição da gordura visceral em um modelo animal de esteato-hepatite não alcoólica. A terapia padrão da hepatite C consiste em uma combinação de interferon peguilado alfa (PEG-IFN-alfa) que estimula o sistema imunológico do hospedeiro para combater a infecção e o composto antiviral ribavirina. Atualmente foram aprovados pelas agências de saúde os inibidores de protease Boceprevir, Telaprevir, Daclatasvir e Simeprevir. No entanto, sua eficiência varia entre os genótipos e as constantes mutações do vírus podem levar a resistência. A falta de uma vacina ou uma terapia definitiva faz com que diversos compostos com diferentes mecanismos de ação sejam testados como possíveis alternativas de tratamento. Tendo em vista a capacidade do YHK de reduzir a esteatose e a importância...
Worldwide is estimated that nearly 170 million people are infected with hepatitis C virus (HCV), highly correlated with the occurrence of chronic hepatitis and hepatocellular carcinoma. Hepatitis C patients present higher prevalence of steatosis when compared with the general population, ranging between 40% and 75%. There are two forms of steatosis in HCV infected patients: metabolic steatosis (risk factors) and cytopathic associated with genotype 3. Lipids are essential for the HCV replication cycle. It acts on different functions: as prosthetic groups into viral proteins and / or cellular cofactors in the HCV replication, as specific HCV components or as a constituent of lipovirals particles. Our group previously reported that the administration of the natural compound Yo Jyo Hen Shi Ko (YHK) inhibits steatosis development, decreases markers of oxidative stress and inflammation, improves aminotransferases concentration and decreases the visceral fat. Standard therapy for hepatitis C is a combination of pegylated interferon alpha (PEG-IFN-alfa), stimulating the host immune system to fight infection and the antiviral compound named ribavirin. Nowadays, Telaprevir, Boceprevir, Sofosbovir and Simeprevir are approved as new anti-HCV drugs; they act as protease inhibitors. Its efficiency, however, varies between genotypes, and the constant mutations of the virus can lead to resistance. The lack of vaccines, or a definitive therapy, stimulates the research of new compounds and alternative treatments. In this study, we evaluated the effect of YHK in HCV replication cycle due to the effect of YHK and the importance of lipid metabolism for HCV. For this purpose we used cell culture techniques allowing the study of different stages of HCV replication cycle: entry (HCVpp), replication - replicons JFH1 NS3-5B and Con1, also replication and infection-JC1-Fluc. We also used active compounds of its ingredients: Panax pseudo ginseng - Notoginsenoside R1...
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Antivirales , Técnicas de Cultivo de Célula , Medicamentos Herbarios Chinos , Hepacivirus , Hepatitis C , Reguladores del Metabolismo de Lípidos , Replicación ViralRESUMEN
Aims: To understand the mechanisms of Early Growth Response Protein 1 (Egr-1) induction upon HSV-1 lytic infection and its roles in regulating viral gene expression and replication. Study Design: Rabbit corneal cell line SIRC and other cell lines were infected by HSV-1 to investigate the Egr-1 induction and its occupancy on the viral genome in different conditions. UV-inactivated HSV-1 and a recombinant virus over-expressing Egr-1 were generated to evaluate the regulatory effects on viral gene expression and replication during the infection. Methodology: Egr-1 induction triggered by viral infection was determined by Western Blot analyses and immune-fluorescent microscopy. Real-time RT-PCR and a novel Cignal™ Reporter Assay were used for quantitative measurement of Egr-1 expression. Chromatin Immuno-precipitation (ChIP) was performed to address the Egr-1 occupancy to the viral regulatory sequences and the influence on viral replication was assessed by plaque assays. Results: Our results indicated that Egr-1 expression requires viral gene expression since the UV-inactivated HSV-1 failed to produce Egr-1 protein. Blockade of viral replication did not block the Egr-1 protein synthesis, supporting the hypothesis that HSV-1 replication was not essential for Egr-1 production. Chromatin immune-precipitation (ChIP) and RT-PCR assays demonstrated that induced Egr-1 was able to interact with key regulatory elements near HSV-1 immediate-early (IE) genes and promote viral gene expression. Recombinant virus overexpressing Egr-1 revealed that Egr-1 enhanced the viral replication and the release of infectious virus. Conclusion: Together these results concluded that HSV-1 triggers the expression of an important host transcription factor Egr-1 via a unique mechanism and benefit the viral gene expression and replication.
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Objective To investigate the influence of extracellular high mobility group box 1 (HMGB1) on viral replication in HTLV-1 infected T cells.Methods HMGB1 in culture supernatants of adult T-cell leukemia virus 1 (HTLV-1) virus-negative cell:Jurkat,MOLT4 cells and HTLV-1 virus-positive cells:MT2,MT4,was detected by ELISA;The HTLV-1 long terminal repeat reporter gene (pHTLV-1-LTR-luc) was transfected into MT2 cells by Tfx-50-mediated transfection,and 0.25,0.50,0.75 μg/ml of HMGB1 polyclonal antibody(HMGB1 PcAb) and its isotype control rabbit IgG antibodies,0.03,0.1,0.3 μg/ml rhHMGB1 and its control PBS,were added into culture supernatant respectively,then luciferase activity was detected after 48 h;Similarly,0.25 μg/ml HMGB1 PcAb and the isotype control antibody,0.3 μg/ml rhH-MGB1 and the control PBS were added to the culture supernatant of MT2 cell,the viral gene,pol1,pol2,gag,env,etc,were performed by real-time PCR.Results Culture supernatant HMGB1 levels has no significant difference between HTLV-1 positive cells MT2 and MT4 and the other two virus-negative T cell lines;Compared with isotype control antibody group,the culture supernatant,to which is added 0.25 μg/ml HMGB1 PcAb,can significantly inhibit the HTLV-1-LTR transcriptional activity and suppress the expressions of the viral gene pol1,pol2,gag,env.Compared with the control PBS,0.3 μg/ml rhHMGB1 significantly promotes the transcriptional activity of the HTLV-1-LTR and the expressions of the viral gene pol1,pol2,gag,env.Conclusion The extracellular HMGB1 can promote viral replication of HTLV-1 infected T cells.
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BACKGROUND/AIMS: Enhanced replication of hepatitis C virus (HCV) is well described in the setting of moderate to severe immunosuppression. The aims of this retrospective study were to determine the incidence of enhanced HCV replication in hepatocellular carcinoma (HCC) patients undergoing transarterial chemolipiodolization (TACL) and to identify the factors associated with enhanced replication of HCV. The clinical pattern of enhanced HCV replication was compared with hepatitis B virus (HBV) reactivation during TACL. METHODS: This study enrolled 49 anti-HCV-seropositive patients who were diagnosed with HCC between January 2005 and December 2010 and who underwent TACL using epirubicin and/or cisplatin with consecutive HCV RNA copies checked. For comparison, 46 hepatitis B surface antigen1-positive patients with HCC who were treated with TACL were also enrolled. The frequency, associated factors, and clinical outcomes of enhanced HCV replication were analyzed and compared with those of HBV reactivation during TACL. RESULTS: Enhanced replication of HCV occurred in 13 (26.5%) of the 49 anti-HCV-seropositive patients during TACL. Of these 13 patients, 4 developed hepatitis, but none of the subjects developed decompensation due to the hepatitis. No significant clinical factors for enhanced HCV replication during TACL were found. Compared with HBV reactivation, the frequency of hepatitis attributed to enhanced HCV replication was significantly lower than that for HBV reactivation (8.2% vs. 23.9%, P=0.036). CONCLUSIONS: TACL can enhance HCV replication; however, the likelihood of hepatitis and decompensation stemming from enhanced HCV replication was lower than that for HBV reactivation in patients undergoing TACL.