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1.
Stem Cell Reports ; 14(3): 493-505, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32160522

RESUMO

Both 3D chromatin architecture and long non-coding RNAs (lncRNAs) play essential roles in pluripotency maintenance. However, whether lncRNAs are involved in organizing 3D chromatin structure remains largely unexplored. We identified 39 lncRNAs bound by Klf4, among which we further revealed the 5430416N02Rik promoter is a chromatin interaction hub. Knockout of the 5430416N02Rik locus reduces the proliferation rate of embryonic stem cells (ESCs). Moreover, deleting both the promoter and the gene body of 5430416N02Rik causes a more severe proliferation defect and has a more profound impact on the transcriptome than deleting the gene body alone. The reduced proliferation of the 5430416N02Rik locus knockout ESCs is mainly due to the downregulation of Mid1, the expression of which requires the inter-chromosomal interaction between Mid1 and 5430416N02Rik loci. In summary, our data demonstrated that the lncRNA 5430416N02Rik gene locus maintains the fast proliferation of ESCs by activating the expression of Mid1 through chromatin interaction.

2.
Proc Natl Acad Sci U S A ; 117(5): 2519-2525, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31964807

RESUMO

The highly conserved COP9 signalosome (CSN), composed of 8 subunits (Cops1 to Cops8), has been implicated in pluripotency maintenance of human embryonic stem cells (ESCs). Yet, the mechanism for the CSN to regulate pluripotency remains elusive. We previously showed that Cops2, independent of the CSN, is essential for the pluripotency maintenance of mouse ESCs. In this study, we set out to investigate how Cops5 and Cops8 regulate ESC differentiation and tried to establish Cops5 and Cops8 knockout (KO) ESC lines by CRISPR/Cas9. To our surprise, no Cops5 KO ESC clones were identified out of 127 clones, while three Cops8 KO ESC lines were established out of 70 clones. We then constructed an inducible Cops5 KO ESC line. Cops5 KO leads to decreased expression of the pluripotency marker Nanog, proliferation defect, G2/M cell-cycle arrest, and apoptosis of ESCs. Further analysis revealed dual roles of Cops5 in maintaining genomic stability of ESCs. On one hand, Cops5 suppresses the autophagic degradation of Mtch2 to direct cellular metabolism toward glycolysis and minimize reactive oxygen species (ROS) production, thereby reducing endogenous DNA damage. On the other hand, Cops5 is required for high DNA damage repair (DDR) activities in ESCs. Without Cops5, elevated ROS and reduced DDR activities lead to DNA damage accumulation in ESCs. Subsequently, p53 is activated to trigger G2/M arrest and apoptosis. Altogether, our studies reveal an essential role of Cops5 in maintaining genome integrity and self-renewal of ESCs by regulating cellular metabolism and DDR pathways.

4.
Endocr Relat Cancer ; 26(1): 153-164, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30139768

RESUMO

There is no effective treatment for patients with poorly differentiated papillary thyroid cancer or anaplastic thyroid cancer (ATC). Anlotinib, a multi-kinase inhibitor, has already shown antitumor effects in various types of carcinoma in a phase I clinical trial. In this study, we aimed to better understand the effect and efficacy of anlotinib against thyroid carcinoma cells in vitro and in vivo. We found that anlotinib inhibits the cell viability of papillary thyroid cancer and ATC cell lines, likely due to abnormal spindle assembly, G2/M arrest, and activation of TP53 upon anlotinib treatment. Moreover, anlotinib suppresses the migration of thyroid cancer cells in vitro and the growth of xenograft thyroid tumors in mice. Our data demonstrate that anlotinib has significant anticancer activity in thyroid cancer, and potentially offers an effective therapeutic strategy for patients of advanced thyroid cancer type.

5.
iScience ; 8: 1-14, 2018 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-30266032

RESUMO

We double-tagged Xist (inactivated X chromosome-specific transcript), a prototype long non-coding RNA pivotal for X chromosome inactivation (XCI), using the programmable RNA sequence binding domain of Pumilio protein, one tag for live-cell imaging and the other replacing A-repeat (a critical domain of Xist) to generate "ΔA mutant" and to tether effector proteins for dissecting Xist functionality. Based on the observation in live cells that the induced XCI in undifferentiated embryonic stem (ES) cells is counteracted by the intrinsic X chromosome reactivation (XCR), we identified Kat8 and Msl2, homologs of Drosophila dosage compensation proteins, as players involved in mammalian XCR. Furthermore, live-cell imaging revealed the obviously undersized ΔA Xist cloud signals, clarifying an issue regarding the previous RNA fluorescence in situ hybridization results. Tethering candidate proteins onto the ΔA mutant reveals the significant roles of Ythdc1, Ezh2, and SPOC (Spen) in Xist-mediated gene silencing and the significant role of Ezh2 in Xist RNA spreading.

6.
Stem Cell Reports ; 11(2): 317-324, 2018 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-30033083

RESUMO

Proper regulation of the cell cycle is essential to safeguard the genomic integrity of embryonic stem cells (ESCs) while maintaining the fast proliferation rate. The pluripotency factor OCT4 has been shown to inhibit CDK1 activation, thus preventing mitotic entry and facilitating the maintenance of genomic integrity. Yet, how ESCs enter mitosis in the presence of OCT4 remains unclear. We previously reported that COPS2 promotes the progression through the G2/M phase of mouse ESCs. In this study, through co-immunoprecipitation and mass spectrometric analysis, we found that COPS2 interacts with OCT4 and CDK1. We further demonstrated that COPS2 stimulates the activity of CDK1/CYCLIN B only when OCT4 is present. Consistently, COPS2 promotes the G2/M transition only in the presence of OCT4 in HeLa cells. Mechanistically, COPS2 attenuates the interaction between OCT4 and CDK1 by sequestering OCT4 and forming a COPS2/CDK1 complex, thus blocking the inhibitory effect of OCT4 on CDK1 activation.


Assuntos
Complexo do Signalossomo COP9/metabolismo , Pontos de Checagem da Fase G2 do Ciclo Celular , Células-Tronco Embrionárias Murinas/metabolismo , Proteínas Nucleares/metabolismo , Fator 3 de Transcrição de Octâmero/antagonistas & inibidores , Fatores de Transcrição/metabolismo , Animais , Proteína Quinase CDC2/metabolismo , Técnicas de Silenciamento de Genes , Camundongos , Células-Tronco Embrionárias Murinas/citologia , Fator 3 de Transcrição de Octâmero/metabolismo , Ligação Proteica
7.
J Mol Biol ; 430(17): 2734-2746, 2018 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-29800566

RESUMO

Xist (inactivated X chromosome specific transcript) is a prototype long noncoding RNA in charge of epigenetic silencing of one X chromosome in each female cell in mammals. In a genetic screen, we identify Mageb3 and its homologs Mageb1 and Mageb2 as genes functionally required for Xist-mediated gene silencing. Mageb1-3 are previously uncharacterized genes belonging to the MAGE (melanoma-associated antigen) gene family. Mageb1-3 are expressed in undifferentiated ES cells and early stages of in vitro differentiation, a critical time window of X chromosome inactivation. Mageb3 showed both cytoplasmic and nuclear localization without enrichment on the inactive X (Xi). Mageb3 interacted with Polycomb group ring finger 3 (Pcgf3), a RING finger protein involved in recruiting Polycomb activities onto Xi. Mageb3 overexpression stabilized Pcgf3 protein. Mageb1-3 gene knockout affected H3K27me3 enrichment and the spreading of gene silencing along Xi. These data suggested that Mageb3 might regulate the recruitment of the Polycomb complex onto Xi and subsequent H3K27me3 modification through Pcgf3. Moreover, the nucleolar enrichment of Mageb3 was diminished when nuclear matrix factor hnRNP U is overexpressed, implying the interaction between Mageb3 and nuclear matrix, which is another possible mechanism for Mageb3 to regulate X chromosome inactivation.


Assuntos
Antígenos de Neoplasias/metabolismo , Embrião de Mamíferos/metabolismo , Fibroblastos/metabolismo , Inativação Gênica , Genoma , Proteínas de Neoplasias/metabolismo , Interferência de RNA , Inativação do Cromossomo X , Animais , Antígenos de Neoplasias/genética , Núcleo Celular , Embrião de Mamíferos/citologia , Fibroblastos/citologia , Ribonucleoproteínas Nucleares Heterogêneas Grupo U/genética , Ribonucleoproteínas Nucleares Heterogêneas Grupo U/metabolismo , Masculino , Camundongos , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/genética , Proteínas do Grupo Polycomb/genética , Proteínas do Grupo Polycomb/metabolismo , Frações Subcelulares , Transcrição Genética
8.
Nat Genet ; 50(3): 443-451, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29483655

RESUMO

Ten-eleven translocation (TET) proteins play key roles in the regulation of DNA-methylation status by oxidizing 5-methylcytosine (5mC) to generate 5-hydroxymethylcytosine (5hmC), which can both serve as a stable epigenetic mark and participate in active demethylation. Unlike the other members of the TET family, TET2 does not contain a DNA-binding domain, and it remains unclear how it is recruited to chromatin. Here we show that TET2 is recruited by the RNA-binding protein Paraspeckle component 1 (PSPC1) through transcriptionally active loci, including endogenous retroviruses (ERVs) whose long terminal repeats (LTRs) have been co-opted by mammalian genomes as stage- and tissue-specific transcriptional regulatory modules. We found that PSPC1 and TET2 contribute to ERVL and ERVL-associated gene regulation by both transcriptional repression via histone deacetylases and post-transcriptional destabilization of RNAs through 5hmC modification. Our findings provide evidence for a functional role of transcriptionally active ERVs as specific docking sites for RNA epigenetic modulation and gene regulation.


Assuntos
Cromatina/metabolismo , Proteínas de Ligação a DNA/metabolismo , Retrovirus Endógenos/fisiologia , Proteínas Nucleares/metabolismo , Células-Tronco Pluripotentes/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas de Ligação a RNA/metabolismo , RNA/fisiologia , Animais , Células Cultivadas , Cromatina/genética , Metilação de DNA , Epigênese Genética/fisiologia , Feminino , Células HEK293 , Humanos , Masculino , Camundongos , Ligação Proteica
9.
Nucleic Acids Res ; 46(7): 3468-3486, 2018 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-29447390

RESUMO

Embryonic stem cells (ESCs) and meiosis are featured by relatively higher frequent homologous recombination associated with DNA double strand breaks (DSB) repair. Here, we show that Pold3 plays important roles in DSB repair, telomere maintenance and genomic stability of both ESCs and spermatocytes in mice. By attempting to generate Pold3 deficient mice using CRISPR/Cas9 or transcription activator-like effector nucleases, we show that complete loss of Pold3 (Pold3-/-) resulted in early embryonic lethality at E6.5. Rapid DNA damage response and massive apoptosis occurred in both outgrowths of Pold3-null (Pold3-/-) blastocysts and Pold3 inducible knockout (iKO) ESCs. While Pold3-/- ESCs were not achievable, Pold3 iKO led to increased DNA damage response, telomere loss and chromosome breaks accompanied by extended S phase. Meanwhile, loss of Pold3 resulted in replicative stress, micronucleation and aneuploidy. Also, DNA repair was impaired in Pold3+/- or Pold3 knockdown ESCs. Moreover, Pold3 mediates DNA replication and repair by regulating 53BP1, RIF1, ATR and ATM pathways. Furthermore, spermatocytes of Pold3 haploinsufficient (Pold3+/-) mice with increasing age displayed impaired DSB repair, telomere shortening and loss, and chromosome breaks, like Pold3 iKO ESCs. These data suggest that Pold3 maintains telomere integrity and genomic stability of both ESCs and meiosis by suppressing replicative stress.


Assuntos
DNA Polimerase III/genética , Replicação do DNA/genética , Células-Tronco Embrionárias/metabolismo , Instabilidade Genômica/genética , Telômero/genética , Animais , Proteínas Mutadas de Ataxia Telangiectasia/genética , Sistemas CRISPR-Cas/genética , Quebras de DNA de Cadeia Dupla , Dano ao DNA/genética , Reparo do DNA/genética , Meiose/genética , Camundongos Knockout , Proteínas de Ligação a Telômeros/genética , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/genética
10.
Stem Cells Int ; 2017: 2601746, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29109740

RESUMO

The CRISPR/Cas9 system provides a powerful method for the genetic manipulation of the mammalian genome, allowing knockout of individual genes as well as the generation of genome-wide knockout cell libraries for genetic screening. However, the diploid status of most mammalian cells restricts the application of CRISPR/Cas9 in genetic screening. Mammalian haploid embryonic stem cells (haESCs) have only one set of chromosomes per cell, avoiding the issue of heterozygous recessive mutations in diploid cells. Thus, the combination of haESCs and CRISPR/Cas9 facilitates the generation of genome-wide knockout cell libraries for genetic screening. Here, we review recent progress in CRISPR/Cas9 and haPSCs and discuss their applications in genetic screening.

12.
Development ; 144(21): 3957-3967, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-28947533

RESUMO

The Hippo pathway modulates the transcriptional activity of Yap to regulate the differentiation of the inner cell mass (ICM) and the trophectoderm (TE) in blastocysts. Yet how Hippo signaling is differentially regulated in ICM and TE cells is poorly understood. Through an inhibitor/activator screen, we have identified Rho as a negative regulator of Hippo in TE cells, and PKA as a positive regulator of Hippo in ICM cells. We further elucidated a novel mechanism by which Rho suppresses Hippo, distinct from the prevailing view that Rho inhibits Hippo signaling through modulating cytoskeleton remodeling and/or cell polarity. Active Rho prevents the phosphorylation of Amot Ser176, thus stabilizing the interaction between Amot and F-actin, and restricting the binding between Amot and Nf2. Moreover, Rho attenuates the interaction between Amot and Nf2 by binding to the coiled-coil domain of Amot. By blocking the association of Nf2 and Amot, Rho suppresses Hippo in TE cells.


Assuntos
Blastocisto/citologia , Blastocisto/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Proteínas dos Microfilamentos/metabolismo , Neurofibromina 2/metabolismo , Transdução de Sinais , Proteínas rho de Ligação ao GTP/metabolismo , Actinas/metabolismo , Animais , Linhagem Celular , Membrana Celular/metabolismo , Polaridade Celular , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Citoesqueleto/metabolismo , Ectoderma/citologia , Ectoderma/metabolismo , Feminino , Peptídeos e Proteínas de Sinalização Intercelular/química , Camundongos Endogâmicos ICR , Proteínas dos Microfilamentos/química , Modelos Biológicos , Fosforilação , Ligação Proteica , Domínios Proteicos , Quinases Associadas a rho/metabolismo
13.
Sci Rep ; 7: 43746, 2017 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-28252054

RESUMO

Intramuscular fat (IMF) content has been generally recognized as a desirable trait in pork meat because of its positive effect on eating quality. An effective approach to enhance IMF content in pork is the generation of transgenic pigs. In this study, we used somatic cell nuclear transfer (SCNT) to generate cloned pigs exhibiting ectopic expression of phosphoenolpyruvate carboxykinase (PEPCK-C) driven by an α-skeletal-actin gene promoter, which was specifically expressed in skeletal muscle. Using qRT-PCR and Western blot analysis, we demonstrated that PEPCK-C was functionally expressed and had a significant effect on total fatty acid content in the skeletal muscle of the transgenic pigs, while the n-6/n-3 polyunsaturated fatty acid (PUFA) ratio showed no difference between transgenic and control pigs. Thus, genetically engineered PEPCK-Cmus pigs may be an effective solution for the production of IMF-enriched pork.


Assuntos
Tecido Adiposo , Expressão Gênica , Carne , Músculo Esquelético/metabolismo , Fosfoenolpiruvato Carboxiquinase (ATP)/genética , Animais , Animais Geneticamente Modificados , Citosol , Ordem dos Genes , Vetores Genéticos/genética , Carne/normas , Fosfoenolpiruvato Carboxiquinase (ATP)/metabolismo , Transporte Proteico , Suínos
15.
Sci Rep ; 7: 43396, 2017 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-28230092

RESUMO

Thyroid is a one of the most important endocrine organs. Understanding the molecular mechanism underlying thyroid development and function, as well as thyroid diseases, is beneficial for the clinical treatment of thyroid diseases and tumors. Through genetic linkage analysis and exome sequencing, we previously identified an uncharacterized gene C14orf93 (RTFC, mouse homolog: 4931414P19Rik) as a novel susceptibility gene for familial non-medullary thyroid carcinoma, and demonstrated its function in promoting thyroid tumor. However, the role of RTFC in thyroid development and function remains unexplored. In this study, we found that knockout of Rtfc compromises the in vitro thyroid differentiation of mouse embryonic stem cells. In contrast, Rtfc-/- mice are viable and fertile, and the size and the morphology of thyroid are not affected by Rtfc knockout. However, female Rtfc-/- mice, but not male Rtfc-/- mice, display mild hypothyroidism. In summary, our data suggest the roles of Rtfc in in vitro thyroid differentiation of embryonic stem cells, and in vivo thyroid function.


Assuntos
Células-Tronco Embrionárias/metabolismo , Hipotireoidismo/genética , Proteínas de Neoplasias/genética , Glândula Tireoide/metabolismo , Animais , Sequência de Bases , Diferenciação Celular , Linhagem Celular , Células-Tronco Embrionárias/patologia , Feminino , Expressão Gênica , Ligação Genética , Humanos , Hipotireoidismo/metabolismo , Hipotireoidismo/patologia , Masculino , Camundongos , Camundongos Knockout , Proteínas de Neoplasias/metabolismo , Fatores Sexuais , Glândula Tireoide/crescimento & desenvolvimento , Glândula Tireoide/patologia
16.
Biochem Biophys Res Commun ; 482(4): 590-596, 2017 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-27864143

RESUMO

The genetic causes for familial nonmedullary thyroid cancer (FNMTC) remain largely unknown. Through genetic linkage analysis and exome sequencing, C14orf93 (RTFC), PYGL, and BMP4 were identified as susceptibility gene candidates in a FNMTC family. By examining the expression and the oncogenic functions of these candidate genes, PYGL and BMP4 were excluded. We further characterized the functions of the uncharacterized gene RTFC in thyroid cancer. RTFC promotes thyroid cancer cell survival under starving conditions, and thyroid cancer cell migration. The R115Q, V205M and G209D RTFC mutants enhance the colony forming capacity of thyroid cancer cells, and are able to transform normal thyroid cells. In summary, our data suggest the roles of RTFC in thyroid carcinogenesis.


Assuntos
Carcinoma/genética , Carcinoma/patologia , Proteínas de Neoplasias/genética , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia , Sequência de Bases , Carcinoma Papilar , Exoma , Feminino , Ligação Genética , Predisposição Genética para Doença , Humanos , Masculino , Linhagem , Mutação Puntual , Câncer Papilífero da Tireoide , Glândula Tireoide/metabolismo
17.
Sci Rep ; 6: 26804, 2016 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-27226076

RESUMO

The COP9 signalosome has been implicated in pluripotency maintenance of human embryonic stem cells. Yet, the mechanism for the COP9 signalosome to regulate pluripotency remains elusive. Through knocking down individual COP9 subunits, we demonstrate that Cops2, but not the whole COP9 signalosome, is essential for pluripotency maintenance in mouse embryonic stem cells. Down-regulation of Cops2 leads to reduced expression of pluripotency genes, slower proliferation rate, G2/M cell cycle arrest, and compromised embryoid differentiation of embryonic stem cells. Cops2 also facilitates somatic cell reprogramming. We further show that Cops2 binds to Nanog protein and prevent the degradation of Nanog by proteasome. Moreover, Cops2 functions as transcriptional corepressor to facilitate pluripotency maintenance. Altogether, our data reveal the essential role and novel mechanisms of Cops2 in pluripotency maintenance.


Assuntos
Complexo do Signalossomo COP9/metabolismo , Células-Tronco Embrionárias/citologia , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Proteína Homeobox Nanog/metabolismo , Proteínas Nucleares/fisiologia , Fatores de Transcrição/fisiologia , Transcrição Genética/genética , Sequência de Aminoácidos , Animais , Complexo do Signalossomo COP9/antagonistas & inibidores , Complexo do Signalossomo COP9/genética , Complexo do Signalossomo COP9/fisiologia , Autorrenovação Celular , Técnicas de Reprogramação Celular , Corpos Embrioides , Células-Tronco Embrionárias/metabolismo , Técnicas de Silenciamento de Genes , Camundongos , Proteína Homeobox Nanog/genética , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Fator 3 de Transcrição de Octâmero/antagonistas & inibidores , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/fisiologia , Estabilidade Proteica , Proteólise , Interferência de RNA , RNA Interferente Pequeno/genética , Fatores de Transcrição SOXC/antagonistas & inibidores , Fatores de Transcrição SOXC/genética , Fatores de Transcrição SOXC/fisiologia , Ovinos/genética , Fatores de Transcrição/antagonistas & inibidores , Fatores de Transcrição/genética
18.
Genom Data ; 7: 73-5, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26981366

RESUMO

Mek inhibition and Erk knockout (KO) have quite distinct effects on pluripotency maintenance in mouse embryonic stem cells (ESCs). To test whether there is an Erk-independent function of Mek, RNA-sequencing (RNA-seq) is carried out on six samples, WT KH2 ESCs treated with or without PD0325901 (PD) for 48 h (KH2_PD and KH2, respectively), iErk1; Erk KO ESCs cultured in the presence of Dox (P0), 48 and 96 h after Dox withdrawal (P1 and P2, respectively), and iErk1; Erk KO ESCs cultured without Dox for 96 h, and treated with PD in the last 48 h (P2_PD). These RNA-seq data demonstrate that Mek inhibition has quite different effect on the transcriptional profile of mouse ESCs, compared to Erk KO. Moreover, a significant fraction of genes is regulated by Mek inhibition, regardless of the presence or absence of Erk, indicating an Erk-independent function of Mek. RNA-seq data are deposited in Gene Expression Omnibus (GEO) datasets under accession number GSE70304.

19.
Exp Hematol ; 44(3): 151-6, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26751246

RESUMO

Erk signaling plays a critical role in maintaining the pluripotency of mouse embryonic stem cells (ESCs). Inhibition of Mek/Erk signaling by pharmacologic Mek inhibitor promotes self-renewal and pluripotency of mouse ESCs. However, knockout of Erk1/2 genes compromises the self-renewal and genomic stability of mouse ESCs. In this review, we summarize recent progress in understanding the role of Erk signaling in pluripotency maintenance, discuss the dual role of Erk in mouse ESCs, and provide explanations for the conflicting data regarding Mek inhibition and Erk knockout. Remaining questions and the prospects of Erk signaling in pluripotency maintenance are also discussed.


Assuntos
Instabilidade Genômica , Sistema de Sinalização das MAP Quinases/fisiologia , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Células-Tronco Embrionárias Murinas/enzimologia , Animais , Camundongos , Camundongos Knockout , Proteína Quinase 3 Ativada por Mitógeno/genética , Células-Tronco Embrionárias Murinas/citologia
20.
Proc Natl Acad Sci U S A ; 112(44): E5936-43, 2015 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-26483458

RESUMO

Inhibition of Mek/Erk signaling by pharmacological Mek inhibitors promotes self-renewal and pluripotency of mouse embryonic stem cells (ESCs). Intriguingly, Erk signaling is essential for human ESC self-renewal. Here we demonstrate that Erk signaling is critical for mouse ESC self-renewal and genomic stability. Erk-depleted ESCs cannot be maintained. Lack of Erk leads to rapid telomere shortening and genomic instability, in association with misregulated expression of pluripotency genes, reduced cell proliferation, G1 cell-cycle arrest, and increased apoptosis. Erk signaling is also required for the activation of differentiation genes but not for the repression of pluripotency genes during ESC differentiation. Furthermore, we find an Erk-independent function of Mek, which may explain the diverse effects of Mek inhibition and Erk knockout on ESC self-renewal. Together, in contrast to the prevailing view, Erk signaling is required for telomere maintenance, genomic stability, and self-renewal of mouse ESCs.


Assuntos
Células-Tronco Embrionárias/citologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Instabilidade Genômica , Transdução de Sinais , Animais , Ciclo Celular , Morte Celular , Células-Tronco Embrionárias/enzimologia , Proteínas de Homeodomínio/genética , Camundongos , Camundongos Knockout , Proteína Homeobox Nanog , Telômero
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