Paloma Hidalgo - Profile on Academia.edu (original) (raw)
Papers by Paloma Hidalgo
Viruses, 2021
The adenovirus type 5 (HAdV-C5) E1 transcription unit encodes regulatory proteins that are essent... more The adenovirus type 5 (HAdV-C5) E1 transcription unit encodes regulatory proteins that are essential for viral replication and transformation. Among these, E1A and E1B-55K act as key multifunctional HAdV-C5 proteins involved in various steps of the viral replication cycle and in virus-induced cell transformation. In this context, HAdV-C5-mediated dysregulations of cellular factors such as the tumor suppressors p53 and pRB have been intensively investigated. However, cellular components of downstream events that could affect infection and viral transformation are widely unknown. We recently observed that cellular FAM111B is highly regulated in an E1A-dependent fashion. Intriguingly, previous reports suggest that FAM111B might play roles in tumorigenesis, but its exact functions are not known to date. Here, we set out to investigate the role of FAM111B in HAdV-C5 infections. We found that (i) FAM111B levels are upregulated early and downregulated late during infection, that (ii) FAM11...
Adenoviruses
Reference Module in Biomedical Sciences, 2021
Reflectivity of Interdigitally and Face-to-Face Poled Surface Acoustic Waves Transducers
P-269 ヒト胎児におけるGastric Emptyingの検討
Boletín Médico del Hospital Infantil de México, 2021
Coronaviruses (CoV) are enveloped, plus-strand RNA viruses that have the largest known RNA genome... more Coronaviruses (CoV) are enveloped, plus-strand RNA viruses that have the largest known RNA genomes and infect birds and mammals, causing various diseases. Human coronaviruses (HCoVs) were first identified in the mid-1960s and have been known to cause enteric or respiratory infections. In the last two decades, three HCoVs have emerged, including the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which initiated the ongoing pandemic. SARS-CoV-2 causes a respiratory illness that presents as a mild upper respiratory disease but may result in acute respiratory distress syndrome, multi-organ failure and can be fatal, especially when underlying comorbidities are present. Children account for a low percentage of coronavirus disease 2019 (COVID-19) cases, with seemingly less severe disease. Most pediatric patients present mild or moderate symptoms or are asymptomatic. However, some cases may be severe. Therefore, SARS-CoV-2 infection and COVID-19 in pediatric patients must be studied in detail. This review describes general features of the molecular biology of CoVs and virus-host interactions that may be implicated in the pathogenesis of SARS-CoV-2.
Viruses, 2021
A common viral replication strategy is characterized by the assembly of intracellular compartment... more A common viral replication strategy is characterized by the assembly of intracellular compartments that concentrate factors needed for viral replication and simultaneously conceal the viral genome from host-defense mechanisms. Recently, various membrane-less virus-induced compartments and cellular organelles have been shown to represent biomolecular condensates (BMCs) that assemble through liquid-liquid phase separation (LLPS). In the present work, we analyze biophysical properties of intranuclear replication compartments (RCs) induced during human adenovirus (HAdV) infection. The viral ssDNA-binding protein (DBP) is a major component of RCs that contains intrinsically disordered and low complexity proline-rich regions, features shared with proteins that drive phase transitions. Using fluorescence recovery after photobleaching (FRAP) and time-lapse studies in living HAdV-infected cells, we show that DBP-positive RCs display properties of liquid BMCs, which can fuse and divide, and e...
FEBS Letters, 2019
The adenovirus E1B 55K (E1B) protein plays major roles in productive adenoviral infection and cel... more The adenovirus E1B 55K (E1B) protein plays major roles in productive adenoviral infection and cellular transformation. Interest in E1B increased because of the potential of adenoviruses as therapeutic vectors, and the E1B gene is commonly deleted from adenovirus vectors for anticancer therapy. E1B activities are spatiotemporally regulated through SUMOylation and phosphorylation, and through interactions with multiple partners that occur presumably at different intracellular sites and times postinfection. E1B is implicated in the formation of viral replication compartments and regulates viral genome replication and transcription, transcriptional repression, degradation of cellular proteins, and several intranuclear steps of viral late mRNA biogenesis. Here, we review advances in our understanding of E1B during productive adenovirus replication and discuss fundamental aspects that remain unresolved.
FEBS Letters, 2019
Adenoviruses induce an extensive reorganization of the host cell nucleus during replication. Such... more Adenoviruses induce an extensive reorganization of the host cell nucleus during replication. Such a process results in the assembly of viral and cellular macromolecules into nuclear structures called adenovirus replication compartments (AdRCs), which function as platforms for viral DNA replication and gene expression. AdRCs co-opt host proteins and cellular pathways that restrict viral replication, suggesting that the mechanisms that control AdRC formation and function are essential for viral replication and lay at the basis of virus-host interactions. Here, we review the hallmarks of AdRCs and recent progress in our understanding of the formation, composition, and function of AdRCs. Furthermore, we discuss how AdRCs facilitate the interplay between viral and cellular machineries and hijack cellular functions to promote viral genome replication and expression.
PLOS ONE, 2019
The E1B 55kDa produced by human adenovirus type 5 is a multifunctional protein that participates ... more The E1B 55kDa produced by human adenovirus type 5 is a multifunctional protein that participates in the regulation of several steps during the viral replication cycle. Previous studies suggest this protein plays an important role in postranscriptional regulation of viral and cellular gene expression, as it is required for the selective accumulation of maximal levels of viral late mRNA in the cytoplasm of the infected cell; however the molecular mechanisms that are altered or regulated by this protein have not been elucidated. A ribonucleoprotein motif that could implicate the direct interaction of the protein with RNA was initially predicted and tested in vitro, but the interaction with RNA could not be detected in infected cells, suggesting the interaction may be weak or transient. Here it was determined that the E1B 55kDa interacts with RNA in the context of the viral infection in non-transformed human cells, and its contribution to the adenovirus replication cycle was evaluated. Using recombinant adenoviruses with amino acid substitutions or a deletion in the ribonucleoprotein motif the interaction of E1B 55kDa with RNA was found to correlate with timely and efficient viral DNA replication and viral late mRNA accumulation and splicing.
Scientific Reports, 2016
Viruses employ a variety of strategies to hijack cellular activities through the orchestrated rec... more Viruses employ a variety of strategies to hijack cellular activities through the orchestrated recruitment of macromolecules to specific virus-induced cellular micro-environments. Adenoviruses (Ad) and other DNA viruses induce extensive reorganization of the cell nucleus and formation of nuclear Replication Compartments (RCs), where the viral genome is replicated and expressed. In this work an automatic algorithm designed for detection and segmentation of RCs using ellipses is presented. Unlike algorithms available in the literature, this approach is deterministic, automatic, and can adjust multiple RCs using ellipses. The proposed algorithm is non iterative, computationally efficient and is invariant to affine transformations. The method was validated over both synthetic images and more than 400 real images of Ad-infected cells at various timepoints of the viral replication cycle obtaining relevant information about the biogenesis of adenoviral RCs. As proof of concept the algorithm was then used to quantitatively compare RCs in cells infected with the adenovirus wild type or an adenovirus mutant that is null for expression of a viral protein that is known to affect activities associated with RCs that result in deficient viral progeny production. Virus replication can induce extensive rearrangement of cellular components that results in de novo formation of specialized intracellular compartments where the viral genome is replicated. Depending on the virus family such compartments, which have been termed viroplasms, virus factories, replication centers or compartments (RCs), may associate with cellular membranes, the cytoskeleton, or nuclear domains 1,2 . In every case RCs assemble complex macromolecular platforms, where viral and cellular proteins responsible for viral genome replication are concentrated, thus increasing viral replication efficiency. Interestingly, the same compartments recruit, regulate and co-opt cellular factors that participate in a variety of host defense mechanisms. Therefore, RCs seem to act as molecular hubs where many aspects of virus-host cell interaction are controlled and there is considerable interest in understanding the impact of their formation on virus replication as well as on the cellular activities that are altered as a consequence of their assembly. Like other DNA viruses that replicate in the cell nucleus, adenoviruses induce formation of RCs (AdRC) that assemble in association or adjacent to specific nuclear domains (ND). However, most aspects of the structure and function of AdRC remain to be explored; some of these include the relationship between their molecular components and the activities they regulate, as well as the molecules involved in their structural integrity and the dynamics of their assembly. A strategy that has been commonly used to study RCs has relied on the phenotypic analysis of recombinant viruses that harbor substitutions or deletions in the genes that are known or suspected to affect RCs formation or activities. Such studies have typically used fluorescence microscopy to screen for alterations in the morphology
Parallelizing the Bayesian Analysis of Blinking and Bleaching for Super-Resolution Microscopy
Communications in Computer and Information Science, 2016
Super-resolution microscopy techniques overcome the diffraction limit of optical microscopy. The ... more Super-resolution microscopy techniques overcome the diffraction limit of optical microscopy. The bayesian analysis of blinking and bleaching (3B analysis) is a super-resolution microscopy method that resolves biological structures with a lateral spatial resolution in the range of 50 nm. This method requires an extensive processing time to generate each super-resolution image. We present the parallelization of the 3B analysis for a personal computer and for a cluster which reduces the time for 3B analysis, and provide Parallel 3B an ImageJ plugin that extends the current implementation of the algorithm to parallel computing.
Journal of Virology, 2016
ABSTRACTAdenovirus (Ad) replication compartments (RC) are nuclear microenvironments where the vir... more ABSTRACTAdenovirus (Ad) replication compartments (RC) are nuclear microenvironments where the viral genome is replicated and a coordinated program of late gene expression is established. These virus-induced nuclear sites seem to behave as central hubs for the regulation of virus-host cell interactions, since proteins that promote efficient viral replication as well as factors that participate in the antiviral response are coopted and concentrated there. To gain further insight into the activities of viral RC, here we report, for the first time, the morphology, composition, and activities of RC isolated from Ad-infected cells. Morphological analyses of isolated RC particles by superresolution microscopy showed that they were indistinguishable from RC within infected cells and that they displayed a dynamic compartmentalization. Furthermore, the RC-containing fractions (RCf) proved to be functional, as they directedde novosynthesis of viral DNA and RNA as well as RNA splicing, activiti...
Chromosome 1p36 loss and COX-2 overexpression predict recurrence-free survival in completely removed meningioma grade I and II
Revista Española de Patología, 2013
ABSTRACT Long follow-up studies show that the 10-year regrowth rate for grade I (benign) and II (... more ABSTRACT Long follow-up studies show that the 10-year regrowth rate for grade I (benign) and II (atypical) meningiomas rises up to 15–25% and 30–35%, respectively, despite aggressive surgery. We investigated completely removed meningiomas grade I and II (n = 135) to identify and compare prognostic markers for tumour recurrence. We determined the immunohistochemical expression of 30 biomarkers, cell death assay by in situ hybridisation (ApopDETEKTM) and loss of chromosome 1p36 by FISH. The univariate statistical analysis showed that WHO grade, high cellularity, nuclear atypia, loss of 1p36 (determined in 20 out of 107 valid cases), expression of COX-2 (9 positive cases and 126 negative cases), Cyclin A, Topoisomerase IIα and MIB1/ki67 were associated with recurrence-free survival. The multivariate linkage analysis for the prognostic variables revealed that only 1p36 loss, expression of COX-2 and MIB1 were independent factors for predicting meningioma recurrence. The statistical analysis of COX-2 and 1p36 loss co-variation showed an antagonistic effect for both prognostic markers. Meningiomas with 1p36 loss showed significant increase of necrosis, nuclear atypia and increased expression of Cyclin E, PAKT, PDGF and p21. COX-2 overexpression was associated with increased VEGF, PDGF, HER2 and MDM2 expression. COX-2 inhibitors may be used as a putative chemopreventive treatment for meningioma recurrence in tumours with COX-2 over-expression.ResumenDiversos estudios con un largo periodo de seguimiento muestran que la tasa de recidiva para los meningiomas grado I (benignos) y II (atípicos) se sitúa entre el 15-25% y el 30-35% respectivamente, a pesar de una cirugía agresiva. Hemos investigado 135 meningiomas completamente resecados para identificar y comparar marcadores pronósticos de recurrencia tumoral. Hemos determinado la expresión inmunohistoquímica de 30 biomarcadores, la muerte celular por apoptosis mediante un ensayo de hibridación in situ (ApopDETEKTM) y las perdidas en el cromosoma 1p36 mediante FISH. El análisis estadístico univariante mostró que el grado tumoral de la OMS, la alta celularidad, la atipia nuclear, las pérdidas en el cromosoma 1p36 (determinadas en 20 de los 107 casos válidos) y la expresión de COX-2 (9 casos positivos y 126 negativos), Ciclina A, Topoisomerasa IIα y MIB1/Ki67 se asociaron con el periodo libre de recurrencia. El análisis multivariante de estas variables pronósticas reveló que solamente las pérdidas en el cromosoma 1p36 y la expresión de COX-2 y MIB1 eran factores independientes para la predicción de recidiva tumoral. El análisis estadístico para la covariación de COX-2 y las perdidas en 1p36 mostraron un efecto antagonista para ambos marcadores. Los meningiomas con pérdidas en 1p36 mostraron un incremento significativo de la necrosis, la atipia nuclear y la expresión de Ciclina E, PAKT, PDGF y p21. La sobreexpresión de COX-2 se asocia a su vez con un aumento de la expresión de VEGF, PDGF, HER2 y MDM2. Los inhibidores selectivos de COX-2 podrían ser usados como un tratamiento quimiopreventivo putativo para evitar la recurrencia en aquellos meningiomas con sobreexpresión de COX-2.
ISRN Virology, 2014
The adenovirus type 5 (Ad5) E1B 55 kDa and E4 Orf6 proteins assemble a Cullin 5-E3 ubiquitin (Ub)... more The adenovirus type 5 (Ad5) E1B 55 kDa and E4 Orf6 proteins assemble a Cullin 5-E3 ubiquitin (Ub) ligase that targets, among other cellular proteins, p53 and the Mre11-Rad50-Nbs1 (MRN) complex for degradation. The latter is also inhibited by the E4 Orf3 protein, which promotes the recruitment of Mre11 into specific nuclear sites to promote viral DNA replication. The activities associated with the E1B 55 kDa and E4 Orf6 viral proteins depend mostly on the assembly of this E3-Ub ligase. However, E1B 55 kDa can also function as an E3-SUMO ligase, suggesting not only that regulation of cellular proteins by these viral early proteins may depend on polyubiquitination and proteasomal degradation but also that SUMOylation of target proteins may play a key role in their activities. Since Mre11 is a target of both the E1B/E4 Orf6 complex and E4 Orf3, we decided to determine whether Mre11 displayed similar properties to those of other cellular targets, in Ad5-infected cells. We have found that...
E1B-55K is a phosphorylation-dependent transcriptional and post-transcriptional regulator of viral gene expression in HAdV-C5 infection
Journal of Virology, 2022
The multifunctional adenoviral E1B-55K phosphoprotein is a major regulator of viral replication a... more The multifunctional adenoviral E1B-55K phosphoprotein is a major regulator of viral replication and plays key roles in virus-mediated cell transformation. While much is known about its function in oncogenic cell transformation, underlying features and exact mechanisms that implicate E1B-55K in regulation of viral gene expression are less well understood. Therefore, this work aimed at unravelling basic intranuclear principles of E1B-55K-regulated viral mRNA biogenesis using wild type HAdV-C5 E1B-55K, a virus mutant with abrogated E1B-55K expression and a mutant that expresses a phosphomimetic E1B-55K. By subnuclear fractionation, mRNA, DNA and protein analyses as well as luciferase reporter assays, we show that (i) E1B-55K promotes efficient release of viral late mRNAs from their site of synthesis in viral replication compartments (RCs) to the surrounding nucleoplasm, that (ii) E1B-55K modulates the rate of viral gene transcription and splicing in RCs, that (iii) E1B-55K participates...
Viruses, 2021
The adenovirus type 5 (HAdV-C5) E1 transcription unit encodes regulatory proteins that are essent... more The adenovirus type 5 (HAdV-C5) E1 transcription unit encodes regulatory proteins that are essential for viral replication and transformation. Among these, E1A and E1B-55K act as key multifunctional HAdV-C5 proteins involved in various steps of the viral replication cycle and in virus-induced cell transformation. In this context, HAdV-C5-mediated dysregulations of cellular factors such as the tumor suppressors p53 and pRB have been intensively investigated. However, cellular components of downstream events that could affect infection and viral transformation are widely unknown. We recently observed that cellular FAM111B is highly regulated in an E1A-dependent fashion. Intriguingly, previous reports suggest that FAM111B might play roles in tumorigenesis, but its exact functions are not known to date. Here, we set out to investigate the role of FAM111B in HAdV-C5 infections. We found that (i) FAM111B levels are upregulated early and downregulated late during infection, that (ii) FAM11...
Adenoviruses
Reference Module in Biomedical Sciences, 2021
Reflectivity of Interdigitally and Face-to-Face Poled Surface Acoustic Waves Transducers
P-269 ヒト胎児におけるGastric Emptyingの検討
Boletín Médico del Hospital Infantil de México, 2021
Coronaviruses (CoV) are enveloped, plus-strand RNA viruses that have the largest known RNA genome... more Coronaviruses (CoV) are enveloped, plus-strand RNA viruses that have the largest known RNA genomes and infect birds and mammals, causing various diseases. Human coronaviruses (HCoVs) were first identified in the mid-1960s and have been known to cause enteric or respiratory infections. In the last two decades, three HCoVs have emerged, including the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which initiated the ongoing pandemic. SARS-CoV-2 causes a respiratory illness that presents as a mild upper respiratory disease but may result in acute respiratory distress syndrome, multi-organ failure and can be fatal, especially when underlying comorbidities are present. Children account for a low percentage of coronavirus disease 2019 (COVID-19) cases, with seemingly less severe disease. Most pediatric patients present mild or moderate symptoms or are asymptomatic. However, some cases may be severe. Therefore, SARS-CoV-2 infection and COVID-19 in pediatric patients must be studied in detail. This review describes general features of the molecular biology of CoVs and virus-host interactions that may be implicated in the pathogenesis of SARS-CoV-2.
Viruses, 2021
A common viral replication strategy is characterized by the assembly of intracellular compartment... more A common viral replication strategy is characterized by the assembly of intracellular compartments that concentrate factors needed for viral replication and simultaneously conceal the viral genome from host-defense mechanisms. Recently, various membrane-less virus-induced compartments and cellular organelles have been shown to represent biomolecular condensates (BMCs) that assemble through liquid-liquid phase separation (LLPS). In the present work, we analyze biophysical properties of intranuclear replication compartments (RCs) induced during human adenovirus (HAdV) infection. The viral ssDNA-binding protein (DBP) is a major component of RCs that contains intrinsically disordered and low complexity proline-rich regions, features shared with proteins that drive phase transitions. Using fluorescence recovery after photobleaching (FRAP) and time-lapse studies in living HAdV-infected cells, we show that DBP-positive RCs display properties of liquid BMCs, which can fuse and divide, and e...
FEBS Letters, 2019
The adenovirus E1B 55K (E1B) protein plays major roles in productive adenoviral infection and cel... more The adenovirus E1B 55K (E1B) protein plays major roles in productive adenoviral infection and cellular transformation. Interest in E1B increased because of the potential of adenoviruses as therapeutic vectors, and the E1B gene is commonly deleted from adenovirus vectors for anticancer therapy. E1B activities are spatiotemporally regulated through SUMOylation and phosphorylation, and through interactions with multiple partners that occur presumably at different intracellular sites and times postinfection. E1B is implicated in the formation of viral replication compartments and regulates viral genome replication and transcription, transcriptional repression, degradation of cellular proteins, and several intranuclear steps of viral late mRNA biogenesis. Here, we review advances in our understanding of E1B during productive adenovirus replication and discuss fundamental aspects that remain unresolved.
FEBS Letters, 2019
Adenoviruses induce an extensive reorganization of the host cell nucleus during replication. Such... more Adenoviruses induce an extensive reorganization of the host cell nucleus during replication. Such a process results in the assembly of viral and cellular macromolecules into nuclear structures called adenovirus replication compartments (AdRCs), which function as platforms for viral DNA replication and gene expression. AdRCs co-opt host proteins and cellular pathways that restrict viral replication, suggesting that the mechanisms that control AdRC formation and function are essential for viral replication and lay at the basis of virus-host interactions. Here, we review the hallmarks of AdRCs and recent progress in our understanding of the formation, composition, and function of AdRCs. Furthermore, we discuss how AdRCs facilitate the interplay between viral and cellular machineries and hijack cellular functions to promote viral genome replication and expression.
PLOS ONE, 2019
The E1B 55kDa produced by human adenovirus type 5 is a multifunctional protein that participates ... more The E1B 55kDa produced by human adenovirus type 5 is a multifunctional protein that participates in the regulation of several steps during the viral replication cycle. Previous studies suggest this protein plays an important role in postranscriptional regulation of viral and cellular gene expression, as it is required for the selective accumulation of maximal levels of viral late mRNA in the cytoplasm of the infected cell; however the molecular mechanisms that are altered or regulated by this protein have not been elucidated. A ribonucleoprotein motif that could implicate the direct interaction of the protein with RNA was initially predicted and tested in vitro, but the interaction with RNA could not be detected in infected cells, suggesting the interaction may be weak or transient. Here it was determined that the E1B 55kDa interacts with RNA in the context of the viral infection in non-transformed human cells, and its contribution to the adenovirus replication cycle was evaluated. Using recombinant adenoviruses with amino acid substitutions or a deletion in the ribonucleoprotein motif the interaction of E1B 55kDa with RNA was found to correlate with timely and efficient viral DNA replication and viral late mRNA accumulation and splicing.
Scientific Reports, 2016
Viruses employ a variety of strategies to hijack cellular activities through the orchestrated rec... more Viruses employ a variety of strategies to hijack cellular activities through the orchestrated recruitment of macromolecules to specific virus-induced cellular micro-environments. Adenoviruses (Ad) and other DNA viruses induce extensive reorganization of the cell nucleus and formation of nuclear Replication Compartments (RCs), where the viral genome is replicated and expressed. In this work an automatic algorithm designed for detection and segmentation of RCs using ellipses is presented. Unlike algorithms available in the literature, this approach is deterministic, automatic, and can adjust multiple RCs using ellipses. The proposed algorithm is non iterative, computationally efficient and is invariant to affine transformations. The method was validated over both synthetic images and more than 400 real images of Ad-infected cells at various timepoints of the viral replication cycle obtaining relevant information about the biogenesis of adenoviral RCs. As proof of concept the algorithm was then used to quantitatively compare RCs in cells infected with the adenovirus wild type or an adenovirus mutant that is null for expression of a viral protein that is known to affect activities associated with RCs that result in deficient viral progeny production. Virus replication can induce extensive rearrangement of cellular components that results in de novo formation of specialized intracellular compartments where the viral genome is replicated. Depending on the virus family such compartments, which have been termed viroplasms, virus factories, replication centers or compartments (RCs), may associate with cellular membranes, the cytoskeleton, or nuclear domains 1,2 . In every case RCs assemble complex macromolecular platforms, where viral and cellular proteins responsible for viral genome replication are concentrated, thus increasing viral replication efficiency. Interestingly, the same compartments recruit, regulate and co-opt cellular factors that participate in a variety of host defense mechanisms. Therefore, RCs seem to act as molecular hubs where many aspects of virus-host cell interaction are controlled and there is considerable interest in understanding the impact of their formation on virus replication as well as on the cellular activities that are altered as a consequence of their assembly. Like other DNA viruses that replicate in the cell nucleus, adenoviruses induce formation of RCs (AdRC) that assemble in association or adjacent to specific nuclear domains (ND). However, most aspects of the structure and function of AdRC remain to be explored; some of these include the relationship between their molecular components and the activities they regulate, as well as the molecules involved in their structural integrity and the dynamics of their assembly. A strategy that has been commonly used to study RCs has relied on the phenotypic analysis of recombinant viruses that harbor substitutions or deletions in the genes that are known or suspected to affect RCs formation or activities. Such studies have typically used fluorescence microscopy to screen for alterations in the morphology
Parallelizing the Bayesian Analysis of Blinking and Bleaching for Super-Resolution Microscopy
Communications in Computer and Information Science, 2016
Super-resolution microscopy techniques overcome the diffraction limit of optical microscopy. The ... more Super-resolution microscopy techniques overcome the diffraction limit of optical microscopy. The bayesian analysis of blinking and bleaching (3B analysis) is a super-resolution microscopy method that resolves biological structures with a lateral spatial resolution in the range of 50 nm. This method requires an extensive processing time to generate each super-resolution image. We present the parallelization of the 3B analysis for a personal computer and for a cluster which reduces the time for 3B analysis, and provide Parallel 3B an ImageJ plugin that extends the current implementation of the algorithm to parallel computing.
Journal of Virology, 2016
ABSTRACTAdenovirus (Ad) replication compartments (RC) are nuclear microenvironments where the vir... more ABSTRACTAdenovirus (Ad) replication compartments (RC) are nuclear microenvironments where the viral genome is replicated and a coordinated program of late gene expression is established. These virus-induced nuclear sites seem to behave as central hubs for the regulation of virus-host cell interactions, since proteins that promote efficient viral replication as well as factors that participate in the antiviral response are coopted and concentrated there. To gain further insight into the activities of viral RC, here we report, for the first time, the morphology, composition, and activities of RC isolated from Ad-infected cells. Morphological analyses of isolated RC particles by superresolution microscopy showed that they were indistinguishable from RC within infected cells and that they displayed a dynamic compartmentalization. Furthermore, the RC-containing fractions (RCf) proved to be functional, as they directedde novosynthesis of viral DNA and RNA as well as RNA splicing, activiti...
Chromosome 1p36 loss and COX-2 overexpression predict recurrence-free survival in completely removed meningioma grade I and II
Revista Española de Patología, 2013
ABSTRACT Long follow-up studies show that the 10-year regrowth rate for grade I (benign) and II (... more ABSTRACT Long follow-up studies show that the 10-year regrowth rate for grade I (benign) and II (atypical) meningiomas rises up to 15–25% and 30–35%, respectively, despite aggressive surgery. We investigated completely removed meningiomas grade I and II (n = 135) to identify and compare prognostic markers for tumour recurrence. We determined the immunohistochemical expression of 30 biomarkers, cell death assay by in situ hybridisation (ApopDETEKTM) and loss of chromosome 1p36 by FISH. The univariate statistical analysis showed that WHO grade, high cellularity, nuclear atypia, loss of 1p36 (determined in 20 out of 107 valid cases), expression of COX-2 (9 positive cases and 126 negative cases), Cyclin A, Topoisomerase IIα and MIB1/ki67 were associated with recurrence-free survival. The multivariate linkage analysis for the prognostic variables revealed that only 1p36 loss, expression of COX-2 and MIB1 were independent factors for predicting meningioma recurrence. The statistical analysis of COX-2 and 1p36 loss co-variation showed an antagonistic effect for both prognostic markers. Meningiomas with 1p36 loss showed significant increase of necrosis, nuclear atypia and increased expression of Cyclin E, PAKT, PDGF and p21. COX-2 overexpression was associated with increased VEGF, PDGF, HER2 and MDM2 expression. COX-2 inhibitors may be used as a putative chemopreventive treatment for meningioma recurrence in tumours with COX-2 over-expression.ResumenDiversos estudios con un largo periodo de seguimiento muestran que la tasa de recidiva para los meningiomas grado I (benignos) y II (atípicos) se sitúa entre el 15-25% y el 30-35% respectivamente, a pesar de una cirugía agresiva. Hemos investigado 135 meningiomas completamente resecados para identificar y comparar marcadores pronósticos de recurrencia tumoral. Hemos determinado la expresión inmunohistoquímica de 30 biomarcadores, la muerte celular por apoptosis mediante un ensayo de hibridación in situ (ApopDETEKTM) y las perdidas en el cromosoma 1p36 mediante FISH. El análisis estadístico univariante mostró que el grado tumoral de la OMS, la alta celularidad, la atipia nuclear, las pérdidas en el cromosoma 1p36 (determinadas en 20 de los 107 casos válidos) y la expresión de COX-2 (9 casos positivos y 126 negativos), Ciclina A, Topoisomerasa IIα y MIB1/Ki67 se asociaron con el periodo libre de recurrencia. El análisis multivariante de estas variables pronósticas reveló que solamente las pérdidas en el cromosoma 1p36 y la expresión de COX-2 y MIB1 eran factores independientes para la predicción de recidiva tumoral. El análisis estadístico para la covariación de COX-2 y las perdidas en 1p36 mostraron un efecto antagonista para ambos marcadores. Los meningiomas con pérdidas en 1p36 mostraron un incremento significativo de la necrosis, la atipia nuclear y la expresión de Ciclina E, PAKT, PDGF y p21. La sobreexpresión de COX-2 se asocia a su vez con un aumento de la expresión de VEGF, PDGF, HER2 y MDM2. Los inhibidores selectivos de COX-2 podrían ser usados como un tratamiento quimiopreventivo putativo para evitar la recurrencia en aquellos meningiomas con sobreexpresión de COX-2.
ISRN Virology, 2014
The adenovirus type 5 (Ad5) E1B 55 kDa and E4 Orf6 proteins assemble a Cullin 5-E3 ubiquitin (Ub)... more The adenovirus type 5 (Ad5) E1B 55 kDa and E4 Orf6 proteins assemble a Cullin 5-E3 ubiquitin (Ub) ligase that targets, among other cellular proteins, p53 and the Mre11-Rad50-Nbs1 (MRN) complex for degradation. The latter is also inhibited by the E4 Orf3 protein, which promotes the recruitment of Mre11 into specific nuclear sites to promote viral DNA replication. The activities associated with the E1B 55 kDa and E4 Orf6 viral proteins depend mostly on the assembly of this E3-Ub ligase. However, E1B 55 kDa can also function as an E3-SUMO ligase, suggesting not only that regulation of cellular proteins by these viral early proteins may depend on polyubiquitination and proteasomal degradation but also that SUMOylation of target proteins may play a key role in their activities. Since Mre11 is a target of both the E1B/E4 Orf6 complex and E4 Orf3, we decided to determine whether Mre11 displayed similar properties to those of other cellular targets, in Ad5-infected cells. We have found that...
E1B-55K is a phosphorylation-dependent transcriptional and post-transcriptional regulator of viral gene expression in HAdV-C5 infection
Journal of Virology, 2022
The multifunctional adenoviral E1B-55K phosphoprotein is a major regulator of viral replication a... more The multifunctional adenoviral E1B-55K phosphoprotein is a major regulator of viral replication and plays key roles in virus-mediated cell transformation. While much is known about its function in oncogenic cell transformation, underlying features and exact mechanisms that implicate E1B-55K in regulation of viral gene expression are less well understood. Therefore, this work aimed at unravelling basic intranuclear principles of E1B-55K-regulated viral mRNA biogenesis using wild type HAdV-C5 E1B-55K, a virus mutant with abrogated E1B-55K expression and a mutant that expresses a phosphomimetic E1B-55K. By subnuclear fractionation, mRNA, DNA and protein analyses as well as luciferase reporter assays, we show that (i) E1B-55K promotes efficient release of viral late mRNAs from their site of synthesis in viral replication compartments (RCs) to the surrounding nucleoplasm, that (ii) E1B-55K modulates the rate of viral gene transcription and splicing in RCs, that (iii) E1B-55K participates...