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1.
Cell ; 158(6): 1254-1269, 2014 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-25215486

RESUMO

Current human pluripotent stem cells lack the transcription factor circuitry that governs the ground state of mouse embryonic stem cells (ESC). Here, we report that short-term expression of two components, NANOG and KLF2, is sufficient to ignite other elements of the network and reset the human pluripotent state. Inhibition of ERK and protein kinase C sustains a transgene-independent rewired state. Reset cells self-renew continuously without ERK signaling, are phenotypically stable, and are karyotypically intact. They differentiate in vitro and form teratomas in vivo. Metabolism is reprogrammed with activation of mitochondrial respiration as in ESC. DNA methylation is dramatically reduced and transcriptome state is globally realigned across multiple cell lines. Depletion of ground-state transcription factors, TFCP2L1 or KLF4, has marginal impact on conventional human pluripotent stem cells but collapses the reset state. These findings demonstrate feasibility of installing and propagating functional control circuitry for ground-state pluripotency in human cells.


Assuntos
Proteínas de Homeodomínio/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Células-Tronco Pluripotentes/metabolismo , Animais , Técnicas Citológicas , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Epigênese Genética , Humanos , Fator 4 Semelhante a Kruppel , Camundongos , Mitocôndrias/metabolismo , Proteína Homeobox Nanog , Células-Tronco Pluripotentes/citologia , Fatores de Transcrição/metabolismo , Transcriptoma
2.
Mol Cell ; 71(1): 56-72.e4, 2018 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-30008319

RESUMO

Chromatin remodeling complexes play essential roles in metazoan development through widespread control of gene expression, but the precise molecular mechanisms by which they do this in vivo remain ill defined. Using an inducible system with fine temporal resolution, we show that the nucleosome remodeling and deacetylation (NuRD) complex controls chromatin architecture and the protein binding repertoire at regulatory regions during cell state transitions. This is primarily exerted through its nucleosome remodeling activity while deacetylation at H3K27 follows changes in gene expression. Additionally, NuRD activity influences association of RNA polymerase II at transcription start sites and subsequent nascent transcript production, thereby guiding the establishment of lineage-appropriate transcriptional programs. These findings provide a detailed molecular picture of genome-wide modulation of lineage-specific transcription by an essential chromatin remodeling complex as well as insight into the orchestration of molecular events involved in transcriptional transitions in vivo. VIDEO ABSTRACT.


Assuntos
Regulação da Expressão Gênica , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Células-Tronco Embrionárias Murinas/metabolismo , Nucleossomos/metabolismo , RNA Polimerase II/metabolismo , Transcrição Gênica , Acetilação , Animais , Linhagem Celular , Histonas/genética , Histonas/metabolismo , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Camundongos , Células-Tronco Embrionárias Murinas/citologia , Nucleossomos/genética , RNA Polimerase II/genética , Sítio de Iniciação de Transcrição
4.
Mol Cell ; 61(2): 260-73, 2016 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-26725008

RESUMO

DNA replication is temporally and spatially organized in all eukaryotes, yet the molecular control and biological function of the replication-timing program are unclear. Rif1 is required for normal genome-wide regulation of replication timing, but its molecular function is poorly understood. Here we show that in mouse embryonic stem cells, Rif1 coats late-replicating domains and, with Lamin B1, identifies most of the late-replicating genome. Rif1 is an essential determinant of replication timing of non-Lamin B1-bound late domains. We further demonstrate that Rif1 defines and restricts the interactions between replication-timing domains during the G1 phase, thereby revealing a function of Rif1 as organizer of nuclear architecture. Rif1 loss affects both number and replication-timing specificity of the interactions between replication-timing domains. In addition, during the S phase, Rif1 ensures that replication of interacting domains is temporally coordinated. In summary, our study identifies Rif1 as the molecular link between nuclear architecture and replication-timing establishment in mammals.


Assuntos
Núcleo Celular/metabolismo , Período de Replicação do DNA , Proteínas de Ligação a Telômeros/metabolismo , Animais , Proliferação de Células , Cromatina/metabolismo , Imunoprecipitação da Cromatina , Ilhas de CpG/genética , Fase G1 , Deleção de Genes , Regulação da Expressão Gênica , Camundongos , Células-Tronco Embrionárias Murinas/citologia , Células-Tronco Embrionárias Murinas/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas de Ligação a Telômeros/química , Sítio de Iniciação de Transcrição
5.
Bioinformatics ; 37(23): 4562-4563, 2021 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-34623394

RESUMO

MOTIVATION: Deciphering nucleosome-nucleosome interactions is an important step toward mesoscale description of chromatin organization but computational tools to perform such analyses are not publicly available. RESULTS: We developed iNucs, a user-friendly and efficient Python-based bioinformatics tool to compute and visualize nucleosome-resolved interactions using standard pairs format input generated from pairtools. AVAILABILITYAND IMPLEMENTATION: https://github.com/Karimi-Lab/inucs/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Nucleossomos , Software
6.
Nature ; 507(7490): 104-8, 2014 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-24463520

RESUMO

Citrullination is the post-translational conversion of an arginine residue within a protein to the non-coded amino acid citrulline. This modification leads to the loss of a positive charge and reduction in hydrogen-bonding ability. It is carried out by a small family of tissue-specific vertebrate enzymes called peptidylarginine deiminases (PADIs) and is associated with the development of diverse pathological states such as autoimmunity, cancer, neurodegenerative disorders, prion diseases and thrombosis. Nevertheless, the physiological functions of citrullination remain ill-defined, although citrullination of core histones has been linked to transcriptional regulation and the DNA damage response. PADI4 (also called PAD4 or PADV), the only PADI with a nuclear localization signal, was previously shown to act in myeloid cells where it mediates profound chromatin decondensation during the innate immune response to infection. Here we show that the expression and enzymatic activity of Padi4 are also induced under conditions of ground-state pluripotency and during reprogramming in mouse. Padi4 is part of the pluripotency transcriptional network, binding to regulatory elements of key stem-cell genes and activating their expression. Its inhibition lowers the percentage of pluripotent cells in the early mouse embryo and significantly reduces reprogramming efficiency. Using an unbiased proteomic approach we identify linker histone H1 variants, which are involved in the generation of compact chromatin, as novel PADI4 substrates. Citrullination of a single arginine residue within the DNA-binding site of H1 results in its displacement from chromatin and global chromatin decondensation. Together, these results uncover a role for citrullination in the regulation of pluripotency and provide new mechanistic insights into how citrullination regulates chromatin compaction.


Assuntos
Montagem e Desmontagem da Cromatina , Cromatina/metabolismo , Citrulina/metabolismo , Histonas/química , Histonas/metabolismo , Células-Tronco Pluripotentes/metabolismo , Processamento de Proteína Pós-Traducional , Animais , Arginina/química , Arginina/metabolismo , Sítios de Ligação , Reprogramação Celular/genética , Cromatina/química , DNA/metabolismo , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Regulação da Expressão Gênica , Hidrolases/metabolismo , Camundongos , Células-Tronco Pluripotentes/citologia , Ligação Proteica , Proteína-Arginina Desiminase do Tipo 4 , Desiminases de Arginina em Proteínas , Proteômica , Especificidade por Substrato , Transcrição Gênica
7.
Development ; 143(17): 3074-84, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27471257

RESUMO

Sall4 is an essential transcription factor for early mammalian development and is frequently overexpressed in cancer. Although it is reported to play an important role in embryonic stem cell (ESC) self-renewal, whether it is an essential pluripotency factor has been disputed. Here, we show that Sall4 is dispensable for mouse ESC pluripotency. Sall4 is an enhancer-binding protein that prevents precocious activation of the neural gene expression programme in ESCs but is not required for maintenance of the pluripotency gene regulatory network. Although a proportion of Sall4 protein physically associates with the Nucleosome Remodelling and Deacetylase (NuRD) complex, Sall4 neither recruits NuRD to chromatin nor influences transcription via NuRD; rather, free Sall4 protein regulates transcription independently of NuRD. We propose a model whereby enhancer binding by Sall4 and other pluripotency-associated transcription factors is responsible for maintaining the balance between transcriptional programmes in pluripotent cells.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Células-Tronco Pluripotentes/metabolismo , Fatores de Transcrição/metabolismo , Animais , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Linhagem Celular , Imunoprecipitação da Cromatina , Biologia Computacional , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Espectrometria de Massas , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Camundongos , Nucleossomos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição/genética
8.
BMC Genomics ; 19(1): 703, 2018 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-30253752

RESUMO

BACKGROUND: RNA-seq is a reference technology for determining alternative splicing at genome-wide level. Exon arrays remain widely used for the analysis of gene expression, but show poor validation rate with regard to splicing events. Commercial arrays that include probes within exon junctions have been developed in order to overcome this problem. We compare the performance of RNA-seq (Illumina HiSeq) and junction arrays (Affymetrix Human Transcriptome array) for the analysis of transcript splicing events. Three different breast cancer cell lines were treated with CX-4945, a drug that severely affects splicing. To enable a direct comparison of the two platforms, we adapted EventPointer, an algorithm that detects and labels alternative splicing events using junction arrays, to work also on RNA-seq data. Common results and discrepancies between the technologies were validated and/or resolved by over 200 PCR experiments. RESULTS: As might be expected, RNA-seq appears superior in cases where the technologies disagree and is able to discover novel splicing events beyond the limitations of physical probe-sets. We observe a high degree of coherence between the two technologies, however, with correlation of EventPointer results over 0.90. Through decimation, the detection power of the junction arrays is equivalent to RNA-seq with up to 60 million reads. CONCLUSIONS: Our results suggest, therefore, that exon-junction arrays are a viable alternative to RNA-seq for detection of alternative splicing events when focusing on well-described transcriptional regions.


Assuntos
Algoritmos , Processamento Alternativo , Perfilação da Expressão Gênica , Análise de Sequência com Séries de Oligonucleotídeos , Análise de Sequência de RNA , Linhagem Celular Tumoral , Humanos , Reação em Cadeia da Polimerase
9.
Brief Bioinform ; 14(5): 563-74, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23543352

RESUMO

The widespread adoption of high-throughput next-generation sequencing (NGS) technology among the Australian life science research community is highlighting an urgent need to up-skill biologists in tools required for handling and analysing their NGS data. There is currently a shortage of cutting-edge bioinformatics training courses in Australia as a consequence of a scarcity of skilled trainers with time and funding to develop and deliver training courses. To address this, a consortium of Australian research organizations, including Bioplatforms Australia, the Commonwealth Scientific and Industrial Research Organisation and the Australian Bioinformatics Network, have been collaborating with EMBL-EBI training team. A group of Australian bioinformaticians attended the train-the-trainer workshop to improve training skills in developing and delivering bioinformatics workshop curriculum. A 2-day NGS workshop was jointly developed to provide hands-on knowledge and understanding of typical NGS data analysis workflows. The road show-style workshop was successfully delivered at five geographically distant venues in Australia using the newly established Australian NeCTAR Research Cloud. We highlight the challenges we had to overcome at different stages from design to delivery, including the establishment of an Australian bioinformatics training network and the computing infrastructure and resource development. A virtual machine image, workshop materials and scripts for configuring a machine with workshop contents have all been made available under a Creative Commons Attribution 3.0 Unported License. This means participants continue to have convenient access to an environment they had become familiar and bioinformatics trainers are able to access and reuse these resources.


Assuntos
Biologia Computacional/educação , Sequenciamento de Nucleotídeos em Larga Escala/estatística & dados numéricos , Austrália , Instrução por Computador/métodos , Comportamento Cooperativo , Currículo , Ensino
10.
Hemasphere ; 7(9): e938, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37637994

RESUMO

Chronic lymphocytic leukemia (CLL) cells are highly dependent on microenvironmental cells and signals. The lymph node (LN) is the critical site of in vivo CLL proliferation and development of resistance to both chemotherapy and targeted agents. We present a new model that incorporates key aspects of the CLL LN, which enables investigation of CLL cells in the context of a protective niche. We describe a three-dimensional (3D) in vitro culture system using ultra-low attachment plates to create spheroids of CLL cells derived from peripheral blood. Starting from CLL:T cell ratios as observed in LN samples, CLL activation was induced by either direct stimulation and/or indirectly via T cells. Compared with two-dimensional cultures, 3D cultures promoted CLL proliferation in a T cell-dependent manner, and enabled expansion for up to 7 weeks, including the formation of follicle-like structures after several weeks of culture. This model enables high-throughput drug screening, of which we describe response to Btk inhibition, venetoclax resistance, and T cell-mediated cytotoxicity as examples. In summary, we present the first LN-mimicking in vitro 3D culture for primary CLL, which enables readouts such as real-time drug screens, kinetic growth assays, and spatial localization. This is the first in vitro CLL system that allows testing of response and resistance to venetoclax and Bruton's tyrosine kinase inhibitors in the context of the tumor microenvironment, thereby opening up new possibilities for clinically useful applications.

11.
IEEE Rev Biomed Eng ; 16: 499-513, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35302938

RESUMO

Technologies for quantifying circulating tumour DNA (ctDNA) in liquid biopsies could enable real-time measurements of cancer progression, profoundly impacting patient care. Sequencing methods can be too complex and time-consuming for regular point-of-care monitoring, but nanotechnology offers an alternative, harnessing the unique properties of objects tens to hundreds of nanometres in size. This systematic review was performed to identify all examples of nanotechnology-based ctDNA detection and assess their potential for clinical use. Google Scholar, PubMed, Web of Science, Google Patents, Espacenet and Embase/MEDLINE were searched up to 23rd March 2021. The review identified nanotechnology-based methods for ctDNA detection for which quantitative measures (e.g., limit of detection, LOD) were reported and biologically relevant samples were used. The pre-defined inclusion criteria were met by 66 records. LODs ranged from 10 zM to 50nM. 25 records presented an LOD of 10fM or below. Nanotechnology-based approaches could provide the basis for the next wave of advances in ctDNA diagnostics, enabling analysis at the point-of-care, but none are currently used clinically. Further work is needed in development and validation; trade-offs are expected between different performance measures e.g., number of sequences detected and time to result.


Assuntos
DNA Tumoral Circulante , Neoplasias , Humanos , DNA Tumoral Circulante/genética , Biomarcadores Tumorais/genética , Nanotecnologia , Biópsia Líquida/métodos
12.
Mol Oncol ; 17(2): 284-297, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36400430

RESUMO

Early data suggested that CC-115, a clinical molecule, already known to inhibit the mammalian target of rapamycin kinase (TORK) and DNA-dependent protein kinase (DNA-PK) may have additional targets beyond TORK and DNA-PK. Therefore, we aimed to identify such target(s) and investigate a potential therapeutic applicability. Functional profiling of 141 cancer cell lines revealed inhibition of kinase suppressor of morphogenesis in genitalia 1 (SMG1), a key regulator of the RNA degradation mechanism nonsense-mediated mRNA decay (NMD), as an additional target of CC-115. CC-115 treatment showed a dose-dependent increase of SMG1-mediated NMD transcripts. A subset of cell lines, including multiple myeloma (MM) cell lines sensitive to the endoplasmic reticulum stress-inducing compound thapsigargin, were highly susceptible to SMG1 inhibition. CC-115 caused the induction of UPR transcripts and cell death by mitochondrial apoptosis, requiring the presence of BAX/BAK and caspase activity. Superior antitumor activity of CC-115 over TORK inhibitors in primary human MM cells and three xenograft mouse models appeared to be via inhibition of SMG1. Our data support further development of SMG1 inhibitors as possible therapeutics in MM.


Assuntos
Mieloma Múltiplo , Degradação do RNAm Mediada por Códon sem Sentido , Animais , Humanos , Camundongos , Linhagem Celular , DNA/metabolismo , Mamíferos/genética , Mamíferos/metabolismo , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Degradação do RNAm Mediada por Códon sem Sentido/genética , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo
13.
Clin Cancer Res ; 28(15): 3367-3377, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35583604

RESUMO

PURPOSE: Cereblon (CRBN), a substrate receptor of the E3 ubiquitin ligase complex CRL4CRBN, is the target of the small molecules lenalidomide and avadomide. Upon binding of the drugs, Aiolos and Ikaros are recruited to the E3 ligase, ubiquitylated, and subsequently degraded. In diffuse large B-cell lymphoma (DLBCL) cells, Aiolos and Ikaros are direct transcriptional repressors of interferon-stimulated genes (ISG) and degradation of these substrates results in increased ISG protein levels resulting in decreased proliferation and apoptosis. Herein, we aimed to uncover the mechanism(s) Aiolos and Ikaros use to repress ISG transcription and provide a mechanistic rationale for a combination strategy to enhance cell autonomous activities of CRBN modulators (CELMoD). EXPERIMENTAL DESIGN: We conducted paired RNA sequencing with histone modification and Aiolos/Ikaros chromatin immunoprecipitation sequencing to identify genes regulated by these transcription factors and to elucidate correlations to drug sensitivity. We confirmed Aiolos/Ikaros mediated transcriptional complex formation in DLBCL patient samples including those treated with avadomide. RESULTS: In DLBCL, the repression of ISG transcription is accomplished in part through recruitment of large transcriptional complexes such as the nucleosome remodeling and deacetylase, which modify the chromatin landscape of these promoters. A rational combination approach of avadomide with a specific histone deacetylase inhibitor leads to a significant increase in ISG transcription compared with either single agent, and synergistic antiproliferative activity in DLBCL cell lines. CONCLUSIONS: Our results provide a novel role for lineage factors Aiolos and Ikaros in DLBCL as well as further insight into the mechanism(s) of Aiolos and Ikaros-mediated transcriptional repression and unique therapeutic combination strategies.


Assuntos
Inibidores de Histona Desacetilases , Linfoma Difuso de Grandes Células B , Inibidores de Histona Desacetilases/farmacologia , Inibidores de Histona Desacetilases/uso terapêutico , Humanos , Fator de Transcrição Ikaros/genética , Fator de Transcrição Ikaros/metabolismo , Fatores Imunológicos/uso terapêutico , Lenalidomida/farmacologia , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/metabolismo , Ubiquitina-Proteína Ligases/genética
14.
AAPS J ; 23(5): 103, 2021 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-34453265

RESUMO

Avadomide is a cereblon E3 ligase modulator and a potent antitumor and immunomodulatory agent. Avadomide trials are challenged by neutropenia as a major adverse event and a dose-limiting toxicity. Intermittent dosing schedules supported by preclinical data provide a strategy to reduce frequency and severity of neutropenia; however, the identification of optimal dosing schedules remains a clinical challenge. Quantitative systems pharmacology (QSP) modeling offers opportunities for virtual screening of efficacy and toxicity levels produced by alternative dose and schedule regimens, thereby supporting decision-making in translational drug development. We formulated a QSP model to capture the mechanism of avadomide-induced neutropenia, which involves cereblon-mediated degradation of transcription factor Ikaros, resulting in a maturation block of the neutrophil lineage. The neutropenia model was integrated with avadomide-specific pharmacokinetic and pharmacodynamic models to capture dose-dependent effects. Additionally, we generated a disease-specific virtual patient population to represent the variability in patient characteristics and response to treatment observed for a diffuse large B-cell lymphoma trial cohort. Model utility was demonstrated by simulating the avadomide effect in the virtual population for various dosing schedules and determining the incidence of high-grade neutropenia, its duration, and the probability of recovery to low-grade neutropenia.


Assuntos
Antineoplásicos/efeitos adversos , Modelos Biológicos , Neutropenia/prevenção & controle , Piperidonas/efeitos adversos , Quinazolinonas/efeitos adversos , Antineoplásicos/administração & dosagem , Variação Biológica da População , Simulação por Computador , Relação Dose-Resposta a Droga , Esquema de Medicação , Humanos , Farmacologia em Rede , Neutropenia/induzido quimicamente , Neutropenia/imunologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/imunologia , Piperidonas/administração & dosagem , Quinazolinonas/administração & dosagem
16.
Dev Cell ; 35(3): 366-82, 2015 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-26555056

RESUMO

Naive pluripotency is manifest in the preimplantation mammalian embryo. Here we determine transcriptome dynamics of mouse development from the eight-cell stage to postimplantation using lineage-specific RNA sequencing. This method combines high sensitivity and reporter-based fate assignment to acquire the full spectrum of gene expression from discrete embryonic cell types. We define expression modules indicative of developmental state and temporal regulatory patterns marking the establishment and dissolution of naive pluripotency in vivo. Analysis of embryonic stem cells and diapaused embryos reveals near-complete conservation of the core transcriptional circuitry operative in the preimplantation epiblast. Comparison to inner cell masses of marmoset primate blastocysts identifies a similar complement of pluripotency factors but use of alternative signaling pathways. Embryo culture experiments further indicate that marmoset embryos utilize WNT signaling during early lineage segregation, unlike rodents. These findings support a conserved transcription factor foundation for naive pluripotency while revealing species-specific regulatory features of lineage segregation.


Assuntos
Blastocisto/citologia , Diferenciação Celular/genética , Linhagem da Célula/genética , Desenvolvimento Embrionário/genética , Camadas Germinativas/citologia , Células-Tronco Pluripotentes/citologia , Animais , Linhagem da Célula/fisiologia , Células-Tronco Embrionárias/citologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Camundongos
17.
Nat Cell Biol ; 16(6): 516-28, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24859004

RESUMO

The precise relationship of embryonic stem cells (ESCs) to cells in the mouse embryo remains controversial. We present transcriptional and functional data to identify the embryonic counterpart of ESCs. Marker profiling shows that ESCs are distinct from early inner cell mass (ICM) and closely resemble pre-implantation epiblast. A characteristic feature of mouse ESCs is propagation without ERK signalling. Single-cell culture reveals that cell-autonomous capacity to thrive when the ERK pathway is inhibited arises late during blastocyst development and is lost after implantation. The frequency of deriving clonal ESC lines suggests that all E4.5 epiblast cells can become ESCs. We further show that ICM cells from early blastocysts can progress to ERK independence if provided with a specific laminin substrate. These findings suggest that formation of the epiblast coincides with competence for ERK-independent self-renewal in vitro and consequent propagation as ESC lines.


Assuntos
Massa Celular Interna do Blastocisto/metabolismo , Diferenciação Celular , Linhagem da Célula , Proliferação de Células , Células-Tronco Embrionárias/metabolismo , Camadas Germinativas/enzimologia , Células-Tronco Pluripotentes/metabolismo , Fatores de Transcrição/metabolismo , Animais , Biomarcadores/metabolismo , Massa Celular Interna do Blastocisto/citologia , Linhagem Celular , Células Clonais , Técnicas de Cultura Embrionária , Implantação do Embrião , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Camadas Germinativas/citologia , Idade Gestacional , Laminina/metabolismo , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Fenótipo , Fatores de Transcrição/genética
18.
Cell Stem Cell ; 10(5): 583-94, 2012 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-22560079

RESUMO

Transcriptional heterogeneity within embryonic stem cell (ESC) populations has been suggested as a mechanism by which a seemingly homogeneous cell population can initiate differentiation into an array of different cell types. Chromatin remodeling proteins have been shown to control transcriptional variability in yeast and to be important for mammalian ESC lineage commitment. Here we show that the Nucleosome Remodeling and Deacetylation (NuRD) complex, which is required for ESC lineage commitment, modulates both transcriptional heterogeneity and the dynamic range of a set of pluripotency genes in ESCs. In self-renewing conditions, the influence of NuRD at these genes is balanced by the opposing action of self-renewal factors. Upon loss of self-renewal factors, the action of NuRD is sufficient to silence transcription of these pluripotency genes, allowing cells to exit self-renewal. We propose that modulation of transcription levels by NuRD is key to maintaining the differentiation responsiveness of pluripotent cells.


Assuntos
Células-Tronco Embrionárias/fisiologia , Regulação da Expressão Gênica no Desenvolvimento , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/metabolismo , Células-Tronco Pluripotentes/fisiologia , Animais , Diferenciação Celular/genética , Linhagem da Célula/genética , Células Cultivadas , Proteínas de Ligação a DNA/genética , Heterogeneidade Genética , Complexo Mi-2 de Remodelação de Nucleossomo e Desacetilase/genética , Camundongos , Camundongos Knockout , Fatores de Transcrição/genética
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