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1.
Nat Struct Mol Biol ; 29(11): 1136-1144, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36369346

RESUMEN

Transcription at most promoters is divergent, initiating at closely spaced oppositely oriented core promoters to produce sense transcripts along with often unstable upstream antisense transcripts (uasTrx). How antisense transcription is regulated and to what extent it is coordinated with sense transcription is not well understood. Here, by combining acute degradation of the multi-functional transcription factor CTCF and nascent transcription measurements, we find that CTCF specifically suppresses antisense but not sense transcription at hundreds of divergent promoters. Primary transcript RNA-FISH shows that CTCF lowers burst fraction but not burst intensity of uasTrx and that co-bursting of sense and antisense transcripts is disfavored. Genome editing, chromatin conformation studies and high-resolution transcript mapping revealed that precisely positioned CTCF directly suppresses the initiation of uasTrx, in a manner independent of its architectural function. In sum, CTCF shapes the transcriptional landscape in part by suppressing upstream antisense transcription.


Asunto(s)
Cromatina , Transcripción Genética , Regiones Promotoras Genéticas , Cromatina/genética , ARN sin Sentido/genética , Regulación de la Expresión Génica
2.
mBio ; 12(4): e0121421, 2021 08 31.
Artículo en Inglés | MEDLINE | ID: mdl-34225494

RESUMEN

As access to high-throughput sequencing technology has increased, the bottleneck in biomedical research has shifted from data generation to data analysis. Here, we describe a modular and extensible framework for didactic instruction in bioinformatics using publicly available RNA sequencing data sets from infectious disease studies, with a focus on host-parasite interactions. We highlight lessons learned from adapting this course for virtual learners during the coronavirus disease 2019 (COVID-19) pandemic.


Asunto(s)
Biología Computacional/educación , Biología Computacional/métodos , Interacciones Huésped-Parásitos/fisiología , Animales , COVID-19/patología , Análisis de Datos , Genómica , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/genética , Plasmodium falciparum/fisiología , Schistosoma mansoni/efectos de los fármacos , Schistosoma mansoni/genética , Schistosoma mansoni/fisiología , Toxoplasma/efectos de los fármacos , Toxoplasma/genética , Toxoplasma/fisiología
3.
J Autoimmun ; 107: 102357, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31780316

RESUMEN

The mechanisms underlying the female-bias in autoimmunity are poorly understood. The contribution of genetic and epigenetic factors from the inactive X chromosome (Xi) are beginning to emerge as critical mediators of autoimmunity in females. Here, we ask how epigenetic features of the Xi change during disease development in B cells from the NZB/W F1 spontaneous mouse model of lupus, which is female-biased. We find that Xist RNA becomes increasingly mislocalized from the Xi with disease onset. While NZB/W F1 naïve B cells have H3K27me3 foci on the Xi, which are missing from healthy C57BL/6 and BALB/c mice, these foci are progressively lost in stimulated B cells during disease. Using single-molecule RNA FISH, we show that the X-linked gene Tlr7 is biallelically expressed in ~20% of NZB/W F1 B cells, and that the amount of biallelic expression does not change with disease. We also present sex-specific gene expression profiles for diseased NZB/W F1 B cells, and find female-specific upregulation of 20 genes, including the autoimmunity-related genes Cxcl13, Msr1, Igj, and Prdm1. Together, these studies provide important insight into the loss of epigenetic modifications from the Xi and changes with gene expression in a mouse model of female-biased SLE.


Asunto(s)
Linfocitos B/inmunología , Linfocitos B/metabolismo , Epigénesis Genética , Lupus Eritematoso Sistémico/etiología , Lupus Eritematoso Sistémico/metabolismo , Inactivación del Cromosoma X/genética , Cromosoma X/genética , Animales , Biomarcadores , Biología Computacional/métodos , Modelos Animales de Enfermedad , Femenino , Regulación de la Expresión Génica , Hibridación Fluorescente in Situ , Lupus Eritematoso Sistémico/diagnóstico , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos NZB , Índice de Severidad de la Enfermedad , Factores Sexuales
4.
Proc Natl Acad Sci U S A ; 116(24): 11916-11925, 2019 06 11.
Artículo en Inglés | MEDLINE | ID: mdl-31138702

RESUMEN

The transcriptional programs that regulate CD8 T-cell differentiation and function in the context of viral infections or tumor immune surveillance have been extensively studied; yet how long noncoding RNAs (lncRNAs) and the loci that transcribe them contribute to the regulation of CD8 T cells during viral infections remains largely unexplored. Here, we report that transcription of the lncRNA Morrbid is specifically induced by T-cell receptor (TCR) and type I IFN stimulation during the early stages of acute and chronic lymphocytic choriomeningitis virus (LCMV) infection. In response to type I IFN, the Morrbid RNA and its locus control CD8 T cell expansion, survival, and effector function by regulating the expression of the proapoptotic factor, Bcl2l11, and by modulating the strength of the PI3K-AKT signaling pathway. Thus, our results demonstrate that inflammatory cue-responsive lncRNA loci represent fundamental mechanisms by which CD8 T cells are regulated in response to pathogens and potentially cancer.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Coriomeningitis Linfocítica/inmunología , ARN Largo no Codificante/inmunología , Animales , Linfocitos T CD8-positivos/virología , Diferenciación Celular/inmunología , Interferón Tipo I/inmunología , Activación de Linfocitos/inmunología , Coriomeningitis Linfocítica/virología , Virus de la Coriomeningitis Linfocítica/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Fosfatidilinositol 3-Quinasas/inmunología , Proteínas Proto-Oncogénicas c-bcl-2/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Transducción de Señal/inmunología
5.
J Leukoc Biol ; 106(4): 919-932, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31125996

RESUMEN

Women and men exhibit differences in innate and adaptive immunity, and women are more susceptible to numerous autoimmune disorders. Two or more X chromosomes increases the risk for some autoimmune diseases, and increased expression of some X-linked immune genes is frequently observed in female lymphocytes from autoimmune patients. Evidence from mouse models of autoimmunity also supports the idea that increased expression of X-linked genes is a feature of female-biased autoimmunity. Recent studies have begun to elucidate the correlation between abnormal X-chromosome inactivation (XCI), an essential mechanism female somatic cells use to equalize X-linked gene dosage between the sexes, and autoimmunity in lymphocytes. In this review, we highlight research describing overexpression of X-linked immunity-related genes and female-biased autoimmunity in both humans and mouse models, and make connections with our recent work elucidating lymphocyte-specific mechanisms of XCI maintenance that become altered in lupus patients.


Asunto(s)
Autoinmunidad/genética , Dosificación de Gen , Genes Ligados a X , Cromosoma X/genética , Animales , Femenino , Humanos , Caracteres Sexuales , Inactivación del Cromosoma X/genética
6.
JCI Insight ; 4(7)2019 04 04.
Artículo en Inglés | MEDLINE | ID: mdl-30944248

RESUMEN

Systemic lupus erythematosus (SLE) is an autoimmune disorder that predominantly affects women and is driven by autoreactive T cell-mediated inflammation. It is known that individuals with multiple X-chromosomes are at increased risk for developing SLE; however, the mechanisms underlying this genetic basis are unclear. Here, we use single cell imaging to determine the epigenetic features of the inactive X (Xi) in developing thymocytes, mature T cell subsets, and T cells from SLE patients and mice. We show that Xist RNA and heterochromatin modifications transiently reappear at the Xi and are missing in mature single positive T cells. Activation of mature T cells restores Xist RNA and heterochromatin marks simultaneously back to the Xi. Notably, X-chromosome inactivation (XCI) maintenance is altered in T cells of SLE patients and late-stage-disease NZB/W F1 female mice, and we show that X-linked genes are abnormally upregulated in SLE patient T cells. SLE T cells also have altered expression of XIST RNA interactome genes, accounting for perturbations of Xi epigenetic features. Thus, abnormal XCI maintenance is a feature of SLE disease, and we propose that Xist RNA localization at the Xi could be an important factor for maintaining dosage compensation of X-linked genes in T cells.


Asunto(s)
Autoinmunidad/genética , Lupus Eritematoso Sistémico/genética , Subgrupos de Linfocitos T/inmunología , Linfocitos T/inmunología , Inactivación del Cromosoma X/inmunología , Animales , Niño , Conjuntos de Datos como Asunto , Modelos Animales de Enfermedad , Femenino , Heterocromatina/genética , Heterocromatina/metabolismo , Histonas/genética , Histonas/metabolismo , Humanos , Lupus Eritematoso Sistémico/sangre , Lupus Eritematoso Sistémico/inmunología , Activación de Linfocitos , Masculino , Ratones , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , RNA-Seq , Factores Sexuales , Análisis de la Célula Individual , Bazo/citología , Subgrupos de Linfocitos T/metabolismo , Linfocitos T/metabolismo , Cromosoma X/genética , Cromosoma X/metabolismo
7.
Stem Cells Dev ; 27(19): 1360-1375, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-29993333

RESUMEN

The placenta is a short-lived tissue required for embryonic growth and survival, and it is fetal derived. Fetal sex influences gestation, and many sexual dimorphic diseases have origins in utero. There is sex-biased gene expression in third-trimester human placentas, yet the origin of sex-specific expression is unknown. Here, we used an in vitro differentiation model to convert human embryonic stem cells (hESCs) into trophoblastic progenitor cells of the first-trimester placenta, which will eventually become mature extravillous trophoblasts and syncytiotrophoblasts. We observed significant sex differences in transcriptomic profiles of hESCs and trophoblastic progenitors, and also with the differentiation process itself. Male cells had higher dosage of X/Y gene pairs relative to female samples, supporting functions for Y-linked genes beyond spermatogenesis in the hESCs and in the early placenta. Female-specific differentiation altered the expression of several thousand genes compared with male cells, and female cells specifically upregulated numerous autosomal genes with known roles in trophoblast function. Sex-biased upregulation of cellular pathways during trophoblast differentiation was also evident. This study is the first to identify sex differences in trophoblastic progenitor cells of the first-trimester human placenta, and reveal early origins for sexual dimorphism.


Asunto(s)
Diferenciación Celular , Células Madre Embrionarias Humanas/citología , Caracteres Sexuales , Transcriptoma , Células Cultivadas , Cromosomas Humanos Y/genética , Femenino , Regulación del Desarrollo de la Expresión Génica , Células Madre Embrionarias Humanas/metabolismo , Humanos , Masculino , Placenta/citología , Embarazo
9.
Front Immunol ; 9: 3087, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30671059

RESUMEN

In females, the long non-coding RNA Xist drives X-chromosome Inactivation (XCI) to equalize X-linked gene dosage between sexes. Unlike other somatic cells, dynamic regulation of Xist RNA and heterochromatin marks on the inactive X (Xi) in female lymphocytes results in biallelic expression of some X-linked genes, including Tlr7, Cxcr3, and Cd40l, implicated in sex-biased autoimmune diseases. We now find that while Xist RNA is dispersed across the nucleus in NK cells and dendritic cells (DCs) and partially co-localizes with H3K27me3 in bone marrow-derived macrophages, it is virtually absent in plasmacytoid DCs (p-DCs). Moreover, H3K27me3 foci are present in only 10-20% of cells and we observed biallelic expression of Tlr7 in p-DCs from wildtype mice and NZB/W F1 mice. Unlike in humans, mouse p-DCs do not exhibit sex differences with interferon alpha production, and interferon signature gene expression in p-DCs is similar between males and females. Despite the absence of Xist RNA from the Xi, female p-DCs maintain dosage compensation of six immunity-related X-linked genes. Thus, immune cells use diverse mechanisms to maintain XCI which could contribute to sex-linked autoimmune diseases.


Asunto(s)
Células Dendríticas/fisiología , Epigénesis Genética , Variación Genética , Células Asesinas Naturales/fisiología , Macrófagos/fisiología , Inactivación del Cromosoma X/genética , Cromosoma X/genética , Análisis de Varianza , Animales , Núcleo Celular/metabolismo , Compensación de Dosificación (Genética) , Femenino , Regulación de la Expresión Génica , Genes Ligados a X , Heterocromatina/metabolismo , Masculino , Glicoproteínas de Membrana/metabolismo , Ratones , Ratones Endogámicos NZB , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Bazo/citología , Receptor Toll-Like 7/metabolismo
10.
PLoS Genet ; 13(10): e1007050, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28991910

RESUMEN

X-chromosome inactivation (XCI) in female lymphocytes is uniquely regulated, as the inactive X (Xi) chromosome lacks localized Xist RNA and heterochromatin modifications. Epigenetic profiling reveals that Xist RNA is lost from the Xi at the pro-B cell stage and that additional heterochromatic modifications are gradually lost during B cell development. Activation of mature B cells restores Xist RNA and heterochromatin to the Xi in a dynamic two-step process that differs in timing and pattern, depending on the method of B cell stimulation. Finally, we find that DNA binding domain of YY1 is necessary for XCI in activated B cells, as ex-vivo YY1 deletion results in loss of Xi heterochromatin marks and up-regulation of X-linked genes. Ectopic expression of the YY1 zinc finger domain is sufficient to restore Xist RNA localization during B cell activation. Together, our results indicate that Xist RNA localization is critical for maintaining XCI in female lymphocytes, and that chromatin changes on the Xi during B cell development and the dynamic nature of YY1-dependent XCI maintenance in mature B cells predisposes X-linked immunity genes to reactivation.


Asunto(s)
Silenciador del Gen , Activación de Linfocitos/genética , Células Precursoras de Linfocitos B/metabolismo , ARN Largo no Codificante/genética , Inactivación del Cromosoma X/genética , Factor de Transcripción YY1/metabolismo , Animales , Epigénesis Genética , Femenino , Eliminación de Gen , Genes Ligados a X , Heterocromatina/genética , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , ARN Largo no Codificante/aislamiento & purificación , Análisis de Secuencia de ARN , Bazo/citología , Regulación hacia Arriba , Cromosoma X/genética , Factor de Transcripción YY1/genética
11.
Nat Commun ; 8: 15397, 2017 06 07.
Artículo en Inglés | MEDLINE | ID: mdl-28589954

RESUMEN

Human WNT10A mutations are associated with developmental tooth abnormalities and adolescent onset of a broad range of ectodermal defects. Here we show that ß-catenin pathway activity and adult epithelial progenitor proliferation are reduced in the absence of WNT10A, and identify Wnt-active self-renewing stem cells in affected tissues including hair follicles, sebaceous glands, taste buds, nails and sweat ducts. Human and mouse WNT10A mutant palmoplantar and tongue epithelia also display specific differentiation defects that are mimicked by loss of the transcription factor KLF4. We find that ß-catenin interacts directly with region-specific LEF/TCF factors, and with KLF4 in differentiating, but not proliferating, cells to promote expression of specialized keratins required for normal tissue structure and integrity. Our data identify WNT10A as a critical ligand controlling adult epithelial proliferation and region-specific differentiation, and suggest downstream ß-catenin pathway activation as a potential approach to ameliorate regenerative defects in WNT10A patients.


Asunto(s)
Diferenciación Celular , Displasia Ectodérmica/genética , Displasia Ectodérmica/patología , Factores de Transcripción de Tipo Kruppel/metabolismo , Mutación/genética , Proteínas del Tejido Nervioso/genética , Células Madre/metabolismo , Proteínas Wnt/genética , Secuencia de Aminoácidos , Animales , Animales Recién Nacidos , Proteína Axina/metabolismo , Secuencia de Bases , Linaje de la Célula , Proliferación Celular , Autorrenovación de las Células , Desarrollo Embrionario , Epidermis/crecimiento & desarrollo , Epidermis/patología , Epidermis/ultraestructura , Epitelio/embriología , Epitelio/metabolismo , Epitelio/ultraestructura , Femenino , Folículo Piloso/metabolismo , Folículo Piloso/patología , Humanos , Factor 4 Similar a Kruppel , Mutación con Pérdida de Función/genética , Masculino , Ratones , Diente Molar/embriología , Diente Molar/metabolismo , Especificidad de Órganos , Linaje , Unión Proteica , Vía de Señalización Wnt , beta Catenina/metabolismo
12.
Mol Cell Biol ; 36(12): 1764-75, 2016 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-27066803

RESUMEN

Long noncoding RNAs (lncRNAs) can regulate gene expression in a cell-specific fashion during development. Here, we identify a novel lncRNA from the X chromosome that we named lncRHOXF1 and which is abundantly expressed in trophectoderm and primitive endoderm cells of human blastocyst-stage embryos. lncRHOXF1 is a spliced and polyadenylated lncRNA about 1 kb in length that is found in both the nuclear and cytoplasmic compartments of in vitro differentiated human trophectoderm progenitor cells. Gain-of-function experiments in human embryonic stem cells, which normally lack lncRHOXF1 RNA, revealed that lncRHOXF1 reduced proliferation and favored cellular differentiation. lncRHOXF1 knockdown using small interfering RNAs (siRNAs) in human trophectoderm progenitors increased expression of viral response genes, including type I interferon. Sendai virus infection of human trophectoderm progenitor cells increased lncRHOXF1 RNA levels, and siRNA-mediated disruption of lncRHOXF1 during infection reduced the expression of viral response genes leading to higher virus replication. Thus, lncRHOXF1 RNA is the first example of a lncRNA that regulates the host response to viral infections in human placental progenitor cells, and we propose that it functions as a repressor of the viral response during early human development.


Asunto(s)
Cromosomas Humanos/genética , Células Madre Embrionarias Humanas/citología , Interferón Tipo I/metabolismo , Placentación , ARN Largo no Codificante/genética , Infecciones por Respirovirus/inmunología , Animales , Diferenciación Celular , Núcleo Celular/genética , Proliferación Celular , Citoplasma/genética , Femenino , Humanos , Ratones , Poliadenilación , Embarazo , Virus Sendai/fisiología , Trofoblastos/citología , Trofoblastos/inmunología , Trofoblastos/virología
13.
Proc Natl Acad Sci U S A ; 113(14): E2029-38, 2016 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-27001848

RESUMEN

Females have a greater immunological advantage than men, yet they are more prone to autoimmune disorders. The basis for this sex bias lies in the X chromosome, which contains many immunity-related genes. Female mammals use X chromosome inactivation (XCI) to generate a transcriptionally silent inactive X chromosome (Xi) enriched with heterochromatic modifications and XIST/Xist RNA, which equalizes gene expression between the sexes. Here, we examine the maintenance of XCI in lymphocytes from females in mice and humans. Strikingly, we find that mature naïve T and B cells have dispersed patterns of XIST/Xist RNA, and they lack the typical heterochromatic modifications of the Xi. In vitro activation of lymphocytes triggers the return of XIST/Xist RNA transcripts and some chromatin marks (H3K27me3, ubiquitin-H2A) to the Xi. Single-cell RNA FISH analysis of female T cells revealed that the X-linked immunity genes CD40LG and CXCR3 are biallelically expressed in some cells. Using knockout and knockdown approaches, we find that Xist RNA-binding proteins, YY1 and hnRNPU, are critical for recruitment of XIST/Xist RNA back to the Xi. Furthermore, we examined B cells from patients with systemic lupus erythematosus, an autoimmune disorder with a strong female bias, and observed different XIST RNA localization patterns, evidence of biallelic expression of immunity-related genes, and increased transcription of these genes. We propose that the Xi in female lymphocytes is predisposed to become partially reactivated and to overexpress immunity-related genes, providing the first mechanistic evidence to our knowledge for the enhanced immunity of females and their increased susceptibility for autoimmunity.


Asunto(s)
Linfocitos/metabolismo , Inactivación del Cromosoma X , Animales , Femenino , Humanos , Inmunidad/genética , Lupus Eritematoso Sistémico/genética , Lupus Eritematoso Sistémico/inmunología , Activación de Linfocitos , Masculino , Ratones , ARN Largo no Codificante/genética , ARN Mensajero/genética
14.
Development ; 139(5): 1023-33, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22318632

RESUMEN

In zebrafish, the MuSK receptor initiates neuromuscular synapse formation by restricting presynaptic growth cones and postsynaptic acetylcholine receptors (AChRs) to the center of skeletal muscle cells. Increasing evidence suggests a role for Wnts in this process, yet how muscle cells respond to Wnt signals is unclear. Here, we show that in vivo, wnt11r and wnt4a initiate MuSK translocation from muscle membranes to recycling endosomes and that this transition is crucial for AChR accumulation at future synaptic sites. Moreover, we demonstrate that components of the planar cell polarity pathway colocalize to recycling endosomes and that this localization is MuSK dependent. Knockdown of several core components disrupts MuSK translocation to endosomes, AChR localization and axonal guidance. We propose that Wnt-induced trafficking of the MuSK receptor to endosomes initiates a signaling cascade to align pre- with postsynaptic elements. Collectively, these findings suggest a general mechanism by which Wnt signals shape synaptic connectivity through localized receptor endocytosis.


Asunto(s)
Endocitosis/fisiología , Proteínas Tirosina Quinasas Receptoras/metabolismo , Sinapsis/fisiología , Proteínas Wnt/metabolismo , Vía de Señalización Wnt/fisiología , Proteína Wnt4/metabolismo , Proteínas de Pez Cebra/metabolismo , Animales , Animales Modificados Genéticamente , Membrana Celular/metabolismo , Polaridad Celular , Endosomas/metabolismo , Proteínas de Homeodominio , Músculo Esquelético/citología , Músculo Esquelético/fisiología , Proteínas Tirosina Quinasas Receptoras/genética , Receptores Colinérgicos/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Sinapsis/ultraestructura , Proteínas Wnt/genética , Proteína Wnt4/genética , Pez Cebra , Proteínas de Pez Cebra/genética , Proteínas de Unión al GTP rab/genética , Proteínas de Unión al GTP rab/metabolismo
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