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1.
Mol Cell ; 56(1): 128-139, 2014 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-25201415

RESUMEN

In unicellular organisms, initiation is the rate-limiting step in transcription; in metazoan organisms, the transition from initiation to productive elongation is also important. Here, we show that the RNA polymerase II (RNAPII)-associated multiprotein complex, Integrator, plays a critical role in both initiation and the release of paused RNAPII at immediate early genes (IEGs) following transcriptional activation by epidermal growth factor (EGF) in human cells. Integrator is recruited to the IEGs in a signal-dependent manner and is required to engage and recruit the super elongation complex (SEC) to EGF-responsive genes to allow release of paused RNAPII and productive transcription elongation.


Asunto(s)
ARN Polimerasa II/metabolismo , Iniciación de la Transcripción Genética , Activación Transcripcional , Factor de Crecimiento Epidérmico/metabolismo , Factor de Crecimiento Epidérmico/fisiología , Células HeLa , Humanos
2.
Clin Exp Immunol ; 206(3): 422-438, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34487545

RESUMEN

Graft versus host disease (GvHD) is a major clinical problem with a significant unmet medical need. We examined the role of cytotoxic T lymphocyte antigen-4 (CTLA-4) in a xenogenic GvHD (xeno-GvHD) model induced by injection of human peripheral mononuclear cells (hPBMC) into irradiated non-obese diabetic (NOD) SCID gamma (NSG) mice. Targeting the CTLA-4 pathway by treatment with CTLA-4 immunoglobulin (Ig) prevented xeno-GvHD, while anti-CTLA-4 antibody treatment exacerbated the lethality and morbidity associated with GvHD. Xeno-GvHD is associated with infiltration of hPBMCs into the lungs, spleen, stomach, liver and colon and an increase in human proinflammatory cytokines, including interferon (IFN)-γ, tumor necrosis factor (TNF)-α and interleukin (IL)-5. Infiltration of donor cells and increases in cytokines were attenuated by treatment with CTLA-4 Ig, but remained either unaffected or enhanced by anti-CTLA-4 antibody. Further, splenic human T cell phenotyping showed that CTLA-4 Ig treatment prevented the engraftment of human CD45+ cells, while anti-CTLA-4 antibody enhanced donor T cell expansion, particularly CD4+ (CD45RO+ ) subsets, including T box transcription factor TBX21 (Tbet)+ CXCR3+ and CD25+ forkhead box protein 3 (FoxP3) cells. Comprehensive analysis of transcriptional profiling of human cells isolated from mouse spleen identified a set of 417 differentially expressed genes (DEGs) by CTLA-4 Ig treatment and 13 DEGs by anti-CTLA-4 antibody treatment. The CTLA-4 Ig regulated DEGs mapped to down-regulated apoptosis, inflammasome, T helper type 17 (Th17) and regulatory T cell (Treg ) pathways and enhanced Toll-like receptor (TLR) receptor signaling, TNF family signaling, complement system and epigenetic and transcriptional regulation, whereas anti-CTLA-4 antibody produced minimal to no impact on these gene pathways. Our results show an important role of co-inhibitory CTLA-4 signaling in xeno-GvHD and suggest the therapeutic utility of other immune checkpoint co-inhibitory pathways in the treatment of immune-mediated diseases driven by hyperactive T cells.


Asunto(s)
Antígeno CTLA-4/inmunología , Citocinas/sangre , Enfermedad Injerto contra Huésped/inmunología , Xenoinjertos/inmunología , Leucocitos Mononucleares/inmunología , Alanina Transaminasa/sangre , Animales , Anticuerpos Monoclonales Humanizados/farmacología , Aspartato Aminotransferasas/sangre , Humanos , Inmunoglobulina G/administración & dosificación , Inmunoglobulina G/inmunología , Ipilimumab/farmacología , Activación de Linfocitos/inmunología , Ratones , Ratones Endogámicos NOD , Ratones SCID , Linfocitos T Citotóxicos/inmunología
3.
Lupus ; 30(5): 795-806, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33626969

RESUMEN

OBJECTIVES: We aimed to identify transcriptional gene signatures predictive of clinical response, for pharmacodynamic evaluation, and to provide mechanistic insight into JNJ-55920839, a human IgG1κ neutralizing mAb targeting IFN-α/IFN-ω, in participants with systemic lupus erythematosus (SLE). METHODS: Blood samples were obtained from SLE participants at baseline and up to Day 130, who received six 10 mg/kg IV doses of JNJ-55920839/placebo every 2 weeks. Participants with mild-to-moderate SLE who achieved clinical responses using SLE Disease Activity Index 2000 Responder Index 4-point change were considered responders. Transcriptional signatures from longitudinally collected blood were generated by RNA-Seq; signatures were generated by microarray from baseline blood samples exposed in vitro to JNJ-55920839 versus untreated. RESULTS: Two gene signatures (IFN-I Signaling and Immunoglobulin Immune Response) exhibited pharmacodynamic changes among JNJ-55920839 responders. The Immunoglobulin signature, but not the IFN-I signature, was elevated at baseline in JNJ-55920839 responders. A gene cluster associated with neutrophil-mediated immunity was reduced at baseline in JNJ-55920839 responders, substantiated by lower neutrophil counts in responders. An IFN-I signature was suppressed by JNJ-55920839 in vitro treatment versus untreated blood to a greater extent in responders before in vivo dosing. CONCLUSIONS: These signatures may enable enrichment for treatment responders when using IFN-I-suppressing treatments in SLE.


Asunto(s)
Anticuerpos Monoclonales Humanizados/farmacología , Interferón-alfa/antagonistas & inhibidores , Lupus Eritematoso Sistémico/tratamiento farmacológico , Administración Intravenosa , Adulto , Anciano , Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/uso terapéutico , Biomarcadores/sangre , Estudios de Casos y Controles , Femenino , Humanos , Inmunoglobulinas/genética , Inmunoglobulinas/inmunología , Interferón Tipo I/efectos de los fármacos , Interferón Tipo I/genética , Interferón-alfa/genética , Interferón-alfa/inmunología , Lupus Eritematoso Sistémico/sangre , Lupus Eritematoso Sistémico/genética , Masculino , Persona de Mediana Edad , Placebos/administración & dosificación , Índice de Severidad de la Enfermedad , Transcripción Genética/genética , Transcriptoma/efectos de los fármacos , Transcriptoma/genética , Ustekinumab/administración & dosificación , Ustekinumab/farmacología , Ustekinumab/uso terapéutico
4.
J Immunol ; 200(2): 512-522, 2018 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-29237779

RESUMEN

Glomerulonephritis is one of the most serious manifestations of systemic lupus erythematous (SLE). Because SLE is ≥10 times more common in women, a role for estrogens in disease pathogenesis has long been suspected. Estrogen receptor α (ERα) is highly expressed in renal tissue. We asked whether ERα expression contributes to the development of immune-mediated nephropathies like in lupus nephritis. We tested the overall effects of estrogen receptors on the immune response by immunization with OVA and induction of chronic graft-versus-host disease in female ERα-knockout mice. We used nephrotoxic serum nephritis as a model of immune-mediated nephropathy. We investigated the influence of ERα on molecular pathways during nephritis by microarray analysis of glomerular extract gene expression. We performed RNA sequencing of lupus patient whole blood to determine common pathways in murine and human nephritis. Absence of ERα protects female mice from developing nephritis, despite the presence of immune complexes and the production of proinflammatory cytokines in the kidneys and normal humoral responses to immunization. Time-course microarray analysis of glomeruli during nephrotoxic serum nephritis revealed significant upregulation of genes related to PPAR-mediated lipid metabolism and downregulation of genes in the retinol metabolism in wild-type females compared with ERα-knockout females. Similarly, RNA sequencing of lupus patient blood revealed similar expression patterns of these same pathways. During nephritis, the altered activity of metabolic pathways, such as retinol metabolism, occurs downstream of ERα activation and is essential for the progression to end-stage renal failure.


Asunto(s)
Metabolismo Energético , Receptor alfa de Estrógeno/metabolismo , Glomerulonefritis/inmunología , Glomerulonefritis/metabolismo , Transducción de Señal , Animales , Complejo Antígeno-Anticuerpo/inmunología , Complejo Antígeno-Anticuerpo/metabolismo , Autoanticuerpos/inmunología , Biología Computacional , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Susceptibilidad a Enfermedades , Receptor alfa de Estrógeno/genética , Expresión Génica , Perfilación de la Expresión Génica , Redes Reguladoras de Genes , Glomerulonefritis/patología , Enfermedad Injerto contra Huésped/inmunología , Enfermedad Injerto contra Huésped/metabolismo , Humanos , Metabolismo de los Lípidos , Lupus Eritematoso Sistémico/complicaciones , Nefritis Lúpica/inmunología , Nefritis Lúpica/metabolismo , Nefritis Lúpica/patología , Ratones , Ratones Noqueados , Factores Sexuales
6.
PLoS Genet ; 13(5): e1006809, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28542170

RESUMEN

Integrator is an RNA polymerase II (RNAPII)-associated complex that was recently identified to have a broad role in both RNA processing and transcription regulation. Importantly, its role in human development and disease is so far largely unexplored. Here, we provide evidence that biallelic Integrator Complex Subunit 1 (INTS1) and Subunit 8 (INTS8) gene mutations are associated with rare recessive human neurodevelopmental syndromes. Three unrelated individuals of Dutch ancestry showed the same homozygous truncating INTS1 mutation. Three siblings harboured compound heterozygous INTS8 mutations. Shared features by these six individuals are severe neurodevelopmental delay and a distinctive appearance. The INTS8 family in addition presented with neuronal migration defects (periventricular nodular heterotopia). We show that the first INTS8 mutation, a nine base-pair deletion, leads to a protein that disrupts INT complex stability, while the second missense mutation introduces an alternative splice site leading to an unstable messenger. Cells from patients with INTS8 mutations show increased levels of unprocessed UsnRNA, compatible with the INT function in the 3'-end maturation of UsnRNA, and display significant disruptions in gene expression and RNA processing. Finally, the introduction of the INTS8 deletion mutation in P19 cells using genome editing alters gene expression throughout the course of retinoic acid-induced neural differentiation. Altogether, our results confirm the essential role of Integrator to transcriptome integrity and point to the requirement of the Integrator complex in human brain development.


Asunto(s)
Discapacidades del Desarrollo/genética , Eliminación de Gen , Mutación Missense , Subunidades de Proteína/genética , ARN Mensajero/metabolismo , Adulto , Empalme Alternativo , Encéfalo/crecimiento & desarrollo , Encéfalo/metabolismo , Encéfalo/patología , Células Cultivadas , Niño , Discapacidades del Desarrollo/diagnóstico , Femenino , Fibroblastos/metabolismo , Células HEK293 , Células HeLa , Heterocigoto , Humanos , Masculino , Mutación , Linaje , Subunidades de Proteína/metabolismo , ARN Mensajero/genética , Síndrome , Transcriptoma , Proteína Wnt1
7.
Nature ; 494(7438): 497-501, 2013 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-23417068

RESUMEN

Recent advances in genomic research have revealed the existence of a large number of transcripts devoid of protein-coding potential in multiple organisms. Although the functional role for long non-coding RNAs (lncRNAs) has been best defined in epigenetic phenomena such as X-chromosome inactivation and imprinting, different classes of lncRNAs may have varied biological functions. We and others have identified a class of lncRNAs, termed ncRNA-activating (ncRNA-a), that function to activate their neighbouring genes using a cis-mediated mechanism. To define the precise mode by which such enhancer-like RNAs function, we depleted factors with known roles in transcriptional activation and assessed their role in RNA-dependent activation. Here we report that depletion of the components of the co-activator complex, Mediator, specifically and potently diminished the ncRNA-induced activation of transcription in a heterologous reporter assay using human HEK293 cells. In vivo, Mediator is recruited to ncRNA-a target genes and regulates their expression. We show that ncRNA-a interact with Mediator to regulate its chromatin localization and kinase activity towards histone H3 serine 10. The Mediator complex harbouring disease- displays diminished ability to associate with activating ncRNAs. Chromosome conformation capture confirmed the presence of DNA looping between the ncRNA-a loci and its targets. Importantly, depletion of Mediator subunits or ncRNA-a reduced the chromatin looping between the two loci. Our results identify the human Mediator complex as the transducer of activating ncRNAs and highlight the importance of Mediator and activating ncRNA association in human disease.


Asunto(s)
Cromatina/genética , Cromatina/metabolismo , Complejo Mediador/metabolismo , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Transcripción Genética , Agenesia del Cuerpo Calloso/genética , Ano Imperforado/genética , Cromatina/química , Estreñimiento/genética , Técnicas de Silenciamiento del Gen , Genes Reporteros/genética , Humanos , Complejo Mediador/química , Complejo Mediador/deficiencia , Complejo Mediador/genética , Discapacidad Intelectual Ligada al Cromosoma X/genética , Conformación Molecular , Hipotonía Muscular/congénito , Hipotonía Muscular/genética , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo , Proteínas de Unión al ARN/química , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Transcripción Genética/genética
8.
J Allergy Clin Immunol ; 141(3): 893-905.e6, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-28579374

RESUMEN

BACKGROUND: Allergic asthma is a prevalent inflammatory disease of the airways caused by dysregulated immune balance in the lungs with incompletely understood pathogenesis. The recently identified type 2 innate lymphoid cells (ILC2s) play significant roles in the pathogenesis of asthma. Although ILC2-activating factors have been identified, the mechanisms that suppress ILC2s remain largely unknown. Plasmacytoid dendritic cells (pDCs) are important in antiviral immunity and in maintaining tolerance to inert antigens. OBJECTIVE: We sought to address the role of pDCs in regulating ILC2 function and ILC2-mediated airway hyperreactivity (AHR) and lung inflammation. METHODS: We used several murine models, including BDCA-2-diphtheria toxin receptor (DTR) transgenic and IFN-α receptor 1-deficient mice, as well as purified primary ILC2s, to reach our objective. We extended and validated our findings to human ILC2s. RESULTS: We show that activation of pDCs through Toll-like receptor 7/8 suppresses ILC2-mediated AHR and airway inflammation and that depletion of pDCs reverses this suppression. We further show that pDCs suppress cytokine production and the proliferation rate while increasing the apoptosis rate of ILC2s through IFN-α production. Transcriptomic analysis of both human and murine ILC2s confirms the activation of regulatory pathways in ILC2s by IFN-α. CONCLUSION: Activation of pDCs alleviates AHR and airway inflammation by suppressing ILC2 function and survival. Our findings reveal a novel regulatory pathway in ILC2-mediated pulmonary inflammation with important clinical implications.


Asunto(s)
Asma/inmunología , Células Dendríticas/inmunología , Inmunidad Innata , Células Plasmáticas/inmunología , Animales , Asma/genética , Asma/patología , Células Dendríticas/patología , Modelos Animales de Enfermedad , Ratones , Ratones Noqueados , Células Plasmáticas/patología
9.
EMBO J ; 33(8): 890-905, 2014 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-24591564

RESUMEN

Breast and ovarian cancer susceptibility genes BRCA1 and PALB2 have enigmatic roles in cellular growth and mammalian development. While these genes are essential for growth during early developmental programs, inactivation later in adulthood results in increased growth and formation of tumors, leading to their designation as tumor suppressors. We performed genome-wide analysis assessing their chromatin residence and gene expression responsiveness using high-throughput sequencing in breast epithelial cells. We found an intimate association between BRCA1 and PALB2 chromatin residence and genes displaying high transcriptional activity. Moreover, our experiments revealed a critical role for BRCA1 and, to a smaller degree, PALB2 in transcriptional responsiveness to NF-κB, a crucial mediator of growth and inflammatory response during development and cancer. Importantly, we also uncovered a vital role for BRCA1 and PALB2 in response to retinoic acid (RA), a growth inhibitory signal in breast cancer cells, which may constitute the basis for their tumor suppressor activity. Taken together, our results highlight an important role for these breast cancer proteins in the regulation of diverse growth regulatory pathways.


Asunto(s)
Proteína BRCA1/metabolismo , Células Epiteliales/fisiología , Proteínas Nucleares/metabolismo , Transcripción Genética , Proteínas Supresoras de Tumor/metabolismo , Línea Celular , Cromatina/metabolismo , Proteína del Grupo de Complementación N de la Anemia de Fanconi , Perfilación de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , FN-kappa B/metabolismo , Tretinoina/metabolismo
10.
J Virol ; 90(1): 345-55, 2016 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-26468528

RESUMEN

UNLABELLED: Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is the EBV-encoded nuclear antigen and sequence-specific DNA binding protein required for viral origin binding and episome maintenance during latency. EBNA1 can also bind to numerous sites in the cellular genome and can provide a host cell survival function, but it is not yet known how EBNA1 sequence-specific binding is responsible for host cell survival. Here, we integrate EBNA1 chromatin immunoprecipitation sequencing (ChIP-Seq) with transcriptome sequencing (RNA-Seq) after EBNA1 depletion to identify cellular genes directly regulated by EBNA1 that are also essential for B-cell survival. We first compared EBNA1 ChIP-Seq patterns in four different EBV-positive cell types, including Burkitt lymphoma (BL) cells, nasopharyngeal carcinoma (NPC) cells, and lymphoblastoid cell lines (LCLs). EBNA1 binds to ~1,000 sites that are mostly invariant among cell types and share a consensus recognition motif. We found that a large subset of EBNA1 binding sites are located proximal to transcription start sites and correlate genome-wide with transcription activity. EBNA1 bound to genes of high significance for B-cell growth and function, including MEF2B, IL6R, and EBF1. EBNA1 depletion from latently infected LCLs results in the loss of cell proliferation and the loss of gene expression for some EBNA1-bound genes, including MEF2B, EBF1, and IL6R. Depletion of MEF2B, EBF1, or IL6R partially phenocopies EBNA1 depletion by decreasing the cell growth and viability of cells latently infected with EBV. These findings suggest that EBNA1 binds to a large cohort of cellular genes important for cell viability and implicates EBNA1 as a critical regulator of transcription of host cell genes important for enhanced survival of latently infected cells. IMPORTANCE: Epstein-Barr virus (EBV) latent infection is responsible for a variety of lymphoid and epithelial cell malignancies. EBNA1 is the EBV-encoded nuclear antigen that is consistently expressed in all EBV-associated cancers. EBNA1 is known to provide a host cell survival function, but the mechanism is not known. EBNA1 is a sequence-specific binding protein important for viral genome maintenance during latency. Here, by integrating ChIP-Seq and RNA-Seq, we demonstrate that EBNA1 binds directly to the promoter regulatory regions and upregulates the transcription of host genes that are important for the survival of EBV-infected cells. Identification of EBNA1 target genes provides potential new targets for therapeutic intervention in EBV-associated disease.


Asunto(s)
Linfocitos B/virología , Proliferación Celular , Antígenos Nucleares del Virus de Epstein-Barr/metabolismo , Herpesvirus Humano 4/fisiología , Receptores de Interleucina-6/metabolismo , Transactivadores/metabolismo , Linfocitos B/fisiología , Línea Celular , Inmunoprecipitación de Cromatina , Proteínas de Unión al ADN/metabolismo , Perfilación de la Expresión Génica , Interacciones Huésped-Patógeno , Humanos , Factores de Transcripción MEF2/metabolismo , Unión Proteica , Análisis de Secuencia de ADN
11.
Nucleic Acids Res ; 43(2): 745-59, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25539921

RESUMEN

The imprinted Kcnq1 domain contains a differentially methylated region (KvDMR) in intron 11 of Kcnq1. The Kcnq1ot1 non-coding RNA emerges from the unmethylated paternal KvDMR in antisense direction, resulting in cis-repression of neighboring genes. The KvDMR encompasses the Kcnq1ot1 promoter, CTCF sites and other DNA elements, whose individual contribution to regulation of the endogenous domain is unknown. We find that paternal inheritance of a deletion of the minimal Kcnq1ot1 promoter derepresses the upstream Cdkn1c gene. Surprisingly, Kcnq1ot1 transcripts continue to emerge from alternative sites, evidence that silencing depends, not on the ncRNA, but on the promoter sequence. Detailed analyses of Kcnq1ot during cardiogenesis show substantial chromatin reorganization coinciding with discontinuous RNA production in both wild-type and mutant mice, with loss of imprinting. We show that CTCF binds to both methylated and unmethylated alleles of the KvDMR. Furthermore, we report a multitude of enhancers within the Kcnq1ot1 region, and present conformational dynamics of a novel heart enhancer engaged in Kcnq1 expression. Our results have important implications on tissue-specific imprinting patterns and how transcriptional mechanisms compete to maximize the expression of vital genes, in addition to shifting our perception on the role of the long ncRNA in regulating this imprinted domain.


Asunto(s)
Elementos de Facilitación Genéticos , Impresión Genómica , Canal de Potasio KCNQ1/genética , ARN Largo no Codificante/metabolismo , Alelos , Animales , Factor de Unión a CCCTC , Inhibidor p57 de las Quinasas Dependientes de la Ciclina/genética , Metilación de ADN , Corazón/crecimiento & desarrollo , Intrones , Canal de Potasio KCNQ1/metabolismo , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Miocardio/metabolismo , Regiones Promotoras Genéticas , Proteínas Represoras/metabolismo
12.
Genome Res ; 23(1): 1-11, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23187890

RESUMEN

We report the genome-wide mapping of ORC1 binding sites in mammals, by chromatin immunoprecipitation and parallel sequencing (ChIP-seq). ORC1 binding sites in HeLa cells were validated as active DNA replication origins (ORIs) using Repli-seq, a method that allows identification of ORI-containing regions by parallel sequencing of temporally ordered replicating DNA. ORC1 sites were universally associated with transcription start sites (TSSs) of coding or noncoding RNAs (ncRNAs). Transcription levels at the ORC1 sites directly correlated with replication timing, suggesting the existence of two classes of ORIs: those associated with moderate/high transcription levels (≥1 RNA copy/cell), firing in early S and mapping to the TSSs of coding RNAs; and those associated with low transcription levels (<1 RNA copy/cell), firing throughout the entire S and mapping to TSSs of ncRNAs. These findings are compatible with a scenario whereby TSS expression levels influence the efficiency of ORC1 recruitment at G(1) and the probability of firing during S.


Asunto(s)
Momento de Replicación del ADN , Genoma Humano , Complejo de Reconocimiento del Origen/metabolismo , Origen de Réplica/genética , Transcripción Genética , Linfocitos T CD4-Positivos , Inmunoprecipitación de Cromatina , Fase G1/genética , Regulación de la Expresión Génica , Células HeLa , Humanos , Complejo de Reconocimiento del Origen/genética , Mapeo Físico de Cromosoma , ARN no Traducido/metabolismo , Fase S/genética , Sitio de Iniciación de la Transcripción
13.
Nature ; 449(7164): 933-7, 2007 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-17898714

RESUMEN

Eukaryotic genomes are organized into active (euchromatic) and inactive (heterochromatic) chromatin domains. Post-translational modifications of histones (or 'marks') are key in defining these functional states, particularly in promoter regions. Mutual regulatory interactions between these marks--and the enzymes that catalyse them--contribute to the shaping of this epigenetic landscape, in a manner that remains to be fully elucidated. We previously observed that asymmetric di-methylation of histone H3 arginine 2 (H3R2me2a) counter-correlates with di- and tri- methylation of H3 lysine 4 (H3K4me2, H3K4me3) on human promoters. Here we show that the arginine methyltransferase PRMT6 catalyses H3R2 di-methylation in vitro and controls global levels of H3R2me2a in vivo. H3R2 methylation by PRMT6 was prevented by the presence of H3K4me3 on the H3 tail. Conversely, the H3R2me2a mark prevented methylation of H3K4 as well as binding to the H3 tail by an ASH2/WDR5/MLL-family methyltransferase complex. Chromatin immunoprecipitation showed that H3R2me2a was distributed within the body and at the 3' end of human genes, regardless of their transcriptional state, whereas it was selectively and locally depleted from active promoters, coincident with the presence of H3K4me3. Hence, the mutual antagonism between H3R2 and H3K4 methylation, together with the association of MLL-family complexes with the basal transcription machinery, may contribute to the localized patterns of H3K4 tri-methylation characteristic of transcriptionally poised or active promoters in mammalian genomes.


Asunto(s)
Arginina/metabolismo , N-Metiltransferasa de Histona-Lisina/metabolismo , Histonas/química , Histonas/metabolismo , Lisina/metabolismo , Proteínas Nucleares/metabolismo , Proteína-Arginina N-Metiltransferasas/metabolismo , Animales , Línea Celular , Línea Celular Tumoral , Inmunoprecipitación de Cromatina , Proteínas de Unión al ADN/metabolismo , Embrión de Mamíferos/citología , Epigénesis Genética , Regulación de la Expresión Génica , N-Metiltransferasa de Histona-Lisina/genética , Humanos , Péptidos y Proteínas de Señalización Intracelular , Metilación , Ratones , Complejos Multiproteicos/metabolismo , Proteínas Nucleares/genética , Regiones Promotoras Genéticas/genética , Proteína-Arginina N-Metiltransferasas/genética , Factores de Transcripción/metabolismo
14.
Nature ; 448(7157): 1063-7, 2007 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-17728759

RESUMEN

The acetyl-transferase Tip60 might influence tumorigenesis in multiple ways. First, Tip60 is a co-regulator of transcription factors that either promote or suppress tumorigenesis, such as Myc and p53. Second, Tip60 modulates DNA-damage response (DDR) signalling, and a DDR triggered by oncogenes can counteract tumour progression. Using E(mu)-myc transgenic mice that are heterozygous for a Tip60 gene (Htatip) knockout allele (hereafter denoted as Tip60+/- mice), we show that Tip60 counteracts Myc-induced lymphomagenesis in a haplo-insufficient manner and in a time window that is restricted to a pre- or early-tumoral stage. Tip60 heterozygosity severely impaired the Myc-induced DDR but caused no general DDR defect in B cells. Myc- and p53-dependent transcription were not affected, and neither were Myc-induced proliferation, activation of the ARF-p53 tumour suppressor pathway or the resulting apoptotic response. We found that the human TIP60 gene (HTATIP) is a frequent target for mono-allelic loss in human lymphomas and head-and-neck and mammary carcinomas, with concomitant reduction in mRNA levels. Immunohistochemical analysis also demonstrated loss of nuclear TIP60 staining in mammary carcinomas. These events correlated with disease grade and frequently concurred with mutation of p53. Thus, in both mouse and human, Tip60 has a haplo-insufficient tumour suppressor activity that is independent from-but not contradictory with-its role within the ARF-p53 pathway. We suggest that this is because critical levels of Tip60 are required for mounting an oncogene-induced DDR in incipient tumour cells, the failure of which might synergize with p53 mutation towards tumour progression.


Asunto(s)
Daño del ADN , Histona Acetiltransferasas/metabolismo , Proteína Oncogénica p55(v-myc)/metabolismo , Oncogenes/genética , Proteínas Supresoras de Tumor/metabolismo , Alelos , Animales , Linfocitos B/metabolismo , Carcinoma/genética , Carcinoma/patología , Células Cultivadas , Genes Supresores de Tumor , Genes myc/genética , Heterocigoto , Histona Acetiltransferasas/genética , Homeostasis , Humanos , Linfoma/genética , Linfoma/patología , Lisina Acetiltransferasa 5 , Ratones , Ratones Transgénicos , Proteína Oncogénica p55(v-myc)/genética , Transactivadores , Transcripción Genética/genética , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Proteínas Supresoras de Tumor/genética
15.
iScience ; 26(7): 107173, 2023 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-37456846

RESUMEN

Systemic lupus erythematosus (SLE) is an autoimmune disease with significant morbidity and mortality. Type I interferon (IFN) drives SLE pathology and plasmacytoid dendritic cells (pDCs) are potent producers of IFN; however, the specific effects of pDC depletion have not been demonstrated. We show CD123 was highly expressed on pDCs and the anti-CD123 antibody CSL362 potently depleted pDCs in vitro. CSL362 pre-treatment abrogated the induction of IFNα and IFN-induced gene transcription following stimulation with SLE patient-derived serum or immune complexes. RNA transcripts induced in pDCs by ex vivo stimulation with TLR ligands were reflected in gene expression profiles of SLE blood, and correlated with disease severity. TLR ligand-induced protein production by SLE patient peripheral mononuclear cells was abrogated by CSL362 pre-treatment including proteins over expressed in SLE patient serum. These findings implicate pDCs as key drivers in the cellular activation and production of soluble factors seen in SLE.

16.
Pharmaceuticals (Basel) ; 16(4)2023 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-37111311

RESUMEN

KRASG12C is one of the most common mutations detected in non-small cell lung cancer (NSCLC) patients, and it is a marker of poor prognosis. The first FDA-approved KRASG12C inhibitors, sotorasib and adagrasib, have been an enormous breakthrough for patients with KRASG12C mutant NSCLC; however, resistance to therapy is emerging. The transcriptional coactivators YAP1/TAZ and the family of transcription factors TEAD1-4 are the downstream effectors of the Hippo pathway and regulate essential cellular processes such as cell proliferation and cell survival. YAP1/TAZ-TEAD activity has further been implicated as a mechanism of resistance to targeted therapies. Here, we investigate the effect of combining TEAD inhibitors with KRASG12C inhibitors in KRASG12C mutant NSCLC tumor models. We show that TEAD inhibitors, while being inactive as single agents in KRASG12C-driven NSCLC cells, enhance KRASG12C inhibitor-mediated anti-tumor efficacy in vitro and in vivo. Mechanistically, the dual inhibition of KRASG12C and TEAD results in the downregulation of MYC and E2F signatures and in the alteration of the G2/M checkpoint, converging in an increase in G1 and a decrease in G2/M cell cycle phases. Our data suggest that the co-inhibition of KRASG12C and TEAD leads to a specific dual cell cycle arrest in KRASG12C NSCLC cells.

17.
PLoS Genet ; 4(11): e1000275, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19043539

RESUMEN

A reciprocal translocation involving chromosomes 8 and 21 generates the AML1/ETO oncogenic transcription factor that initiates acute myeloid leukemia by recruiting co-repressor complexes to DNA. AML1/ETO interferes with the function of its wild-type counterpart, AML1, by directly targeting AML1 binding sites. However, transcriptional regulation determined by AML1/ETO probably relies on a more complex network, since the fusion protein has been shown to interact with a number of other transcription factors, in particular E-proteins, and may therefore target other sites on DNA. Genome-wide chromatin immunoprecipitation and expression profiling were exploited to identify AML1/ETO-dependent transcriptional regulation. AML1/ETO was found to co-localize with AML1, demonstrating that the fusion protein follows the binding pattern of the wild-type protein but does not function primarily by displacing it. The DNA binding profile of the E-protein HEB was grossly rearranged upon expression of AML1/ETO, and the fusion protein was found to co-localize with both AML1 and HEB on many of its regulated targets. Furthermore, the level of HEB protein was increased in both primary cells and cell lines expressing AML1/ETO. Our results suggest a major role for the functional interaction of AML1/ETO with AML1 and HEB in transcriptional regulation determined by the fusion protein.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Subunidad alfa 2 del Factor de Unión al Sitio Principal/metabolismo , Proteínas de Fusión Oncogénica/genética , Animales , Sitios de Unión , Línea Celular Tumoral , Cromosomas Humanos Par 19/genética , Células HeLa , Humanos , Ratones , Proteínas de Fusión Oncogénica/metabolismo , Regiones Promotoras Genéticas , Proteína 1 Compañera de Translocación de RUNX1 , Transcripción Genética , Células U937
18.
Arthritis Rheumatol ; 73(3): 472-477, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33010188

RESUMEN

OBJECTIVE: In a previously reported phase II randomized, placebo-controlled, interventional trial, we demonstrated that treatment with ustekinumab, an anti-interleukin-12 (IL-12)/IL-23 p40 neutralizing monoclonal antibody, improved global and organ-specific measures of disease activity in patients with active systemic lupus erythematosus (SLE). Utilizing the biomarker data from this phase II clinical study, we sought to determine whether modulation of the expression of IL-12, IL-23, or both cytokines by ustekinumab is associated with clinical efficacy in patients with SLE. METHODS: This phase II randomized, placebo-controlled study enrolled 102 patients with autoantibody-positive SLE whose disease remained active despite standard-of-care therapy. Patients were randomized at a 3:2 ratio to receive ~6 mg/kg ustekinumab intravenously or placebo at week 0, followed by subcutaneous injections of 90 mg ustekinumab or placebo every 8 weeks, with placebo crossover to 90 mg ustekinumab every 8 weeks. The SLE Responder Index 4 (SRI-4) at week 24 was used to determine which patients could be classified as ustekinumab responders and which could be classified as nonresponders. In addition to measurements of p40 and IL-23, serum levels of interferon-γ (IFNγ), IL-17A, IL-17F, and IL-22, as a proxy for the IL-12 and IL-23 pathways, were quantified by immunoassay. RESULTS: Changes in the serum levels of IL-17A, IL-17F, and IL-22 at different time points after treatment were not consistently significantly associated with an SRI-4 clinical response to ustekinumab in patients with SLE. In contrast, an SRI-4 response to ustekinumab was significantly associated (P < 0.01) with durable reductions in the serum IFNγ protein levels at several time points relative to baseline, which was not observed in ustekinumab nonresponders or patients who received placebo. CONCLUSION: While not diminishing a potential role of IL-23, these serum biomarker assessments indicate that IL-12 blockade has an important role in the mechanism of action of ustekinumab treatment in patients with SLE.


Asunto(s)
Interferón gamma/inmunología , Subunidad p40 de la Interleucina-12/inmunología , Lupus Eritematoso Sistémico/tratamiento farmacológico , Ustekinumab/uso terapéutico , Adolescente , Adulto , Anciano , Femenino , Humanos , Subunidad p40 de la Interleucina-12/antagonistas & inhibidores , Interleucina-17/inmunología , Interleucina-23/inmunología , Interleucinas/inmunología , Lupus Eritematoso Sistémico/inmunología , Lupus Eritematoso Sistémico/fisiopatología , Masculino , Persona de Mediana Edad , Proteómica , Resultado del Tratamiento , Adulto Joven , Interleucina-22
19.
Lancet Rheumatol ; 2(10): e613-e622, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38273624

RESUMEN

BACKGROUND: Activation of the type I interferon (IFN) pathway is associated with systemic lupus erythematosus (SLE). We assessed the safety and tolerability of JNJ-55920839, a human monoclonal antibody that selectively neutralises most human IFNα subtypes and IFNω, in healthy participants and those with SLE. METHODS: This was a two-part, first-in-human, phase 1, randomised, double-blind, placebo-controlled, multicentre study of single-ascending intravenous doses of 0·3-15 mg/kg or a single subcutaneous dose of 1 mg/kg JNJ-55920839 administered to healthy participants (part A) and multiple intravenous doses of 10 mg/kg JNJ-55920839 administered to participants with SLE (part B). Healthy men and women (women had to be postmenopausal or surgically sterile) aged 18-55 years; bodyweight of 50-90 kg; and body-mass index (BMI) of 18-30 kg/m2 were eligible for inclusion in part A. Men and women with SLE were recruited to part B, fertile female participants were required to have a negative pregnancy test result before and during the study and be using two highly effective methods of birth control. The inclusion criteria for participants with SLE in part B matched part A, except for bodyweight (40-100 kg). In both parts, participants were randomly assigned (3:1) to receive JNJ-55920839 or placebo; a computer-generated randomisation schedule was used in part A, and randomisation was stratified by racial and ethnic subpopulation and elevated levels of serological disease activity in part B. The primary outcome was evaluation of safety and tolerability of the study regimen assessed using clinical and laboratory tests compared with placebo. This study is registered with ClinicalTrials.gov, NCT02609789. FINDINGS: Between Dec 11, 2015, and Sept 20, 2018, 48 healthy participants from a single site and 28 participants with mild-to-moderate SLE from 19 participating centres in seven countries were enrolled in the study. 12 healthy volunteers in part A and eight participants with SLE in part B received placebo. The most common treatment-emergent adverse events in both part A and B were in the system organ class of infections and infestations with a higher percentage of participants administered JNJ-55920839 with infections (ten [28%] of 36 in part A and nine [50%] of 18 in part B) than those exposed to placebo (two [17%] of 12 in part A and one [13%] of eight in part B). Particpants in part B were permitted to continue on defined ongoing standard of care medications. In two participants with SLE, locally disseminated herpes zoster of the skin was reported. No other clinically significant safety or tolerability issues were identified beyond the infections observed in participants treated with JNJ-55920839. INTERPRETATION: JNJ-55920839 was well tolerated and safe. Additional studies are warranted to determine optimal dosing of patients and further explore safety. FUNDING: Janssen.

20.
Bioinformatics ; 24(24): 2918-20, 2008 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-18945685

RESUMEN

SUMMARY: CARPET (collection of automated routine programs for easy tiling) is a set of Perl, Python and R scripts, integrated on the Galaxy2 web-based platform, for the analysis of ChIP-chip and expression tiling data, both for standard and custom chip designs. CARPET allows rapid experimental data entry, simple quality control, normalization, easy identification and annotation of enriched ChIP-chip regions, detection of the absolute or relative transcriptional status of genes assessed by expression tiling experiments and, more importantly, it allows the integration of ChIP-chip and expression data. Results can be visualized instantly in a genomic context within the UCSC genome browser as graph-based custom tracks through Galaxy2. All generated and uploaded data can be stored within sessions and are easily shared with other users. AVAILABILITY: http://bio.ifom-ieo-campus.it/galaxy


Asunto(s)
Inmunoprecipitación de Cromatina/métodos , Perfilación de la Expresión Génica/métodos , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Programas Informáticos , Bases de Datos Genéticas , Genoma , Internet , Transcripción Genética
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