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1.
Nat Commun ; 11(1): 4133, 2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32807777

RESUMO

Chromatin organization is critical for cell growth, differentiation, and disease development, however, its functions in peripheral myelination and myelin repair remain elusive. In this report, we demonstrate that the CCCTC-binding factor (CTCF), a crucial chromatin organizer, is essential for Schwann cell myelination and myelin regeneration after nerve injury. Inhibition of CTCF or its deletion blocks Schwann cell differentiation at the pro-myelinating stage, whereas overexpression of CTCF promotes the myelination program. We find that CTCF establishes chromatin interaction loops between enhancer and promoter regulatory elements and promotes expression of a key pro-myelinogenic factor EGR2. In addition, CTCF interacts with SUZ12, a component of polycomb-repressive-complex 2 (PRC2), to repress the transcriptional program associated with negative regulation of Schwann cell maturation. Together, our findings reveal a dual role of CTCF-dependent chromatin organization in promoting myelinogenic programs and recruiting chromatin-repressive complexes to block Schwann cell differentiation inhibitors to control peripheral myelination and repair.


Assuntos
Fator de Ligação a CCCTC/metabolismo , Cromatina/metabolismo , Proteína 2 de Resposta de Crescimento Precoce/metabolismo , Bainha de Mielina/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Animais , Fator de Ligação a CCCTC/genética , Células Cultivadas , Imunoprecipitação da Cromatina , Proteína 2 de Resposta de Crescimento Precoce/genética , Camundongos , Bainha de Mielina/genética , Complexo Repressor Polycomb 2/genética , Ratos , Células de Schwann/metabolismo
2.
Proc Natl Acad Sci U S A ; 117(28): 16660-16666, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32601198

RESUMO

Molecular mechanisms enabling the switching and maintenance of epigenetic states are not fully understood. Distinct histone modifications are often associated with ON/OFF epigenetic states, but how these states are stably maintained through DNA replication, yet in certain situations switch from one to another remains unclear. Here, we address this problem through identification of Arabidopsis INCURVATA11 (ICU11) as a Polycomb Repressive Complex 2 accessory protein. ICU11 robustly immunoprecipitated in vivo with PRC2 core components and the accessory proteins, EMBRYONIC FLOWER 1 (EMF1), LIKE HETEROCHROMATIN PROTEIN1 (LHP1), and TELOMERE_REPEAT_BINDING FACTORS (TRBs). ICU11 encodes a 2-oxoglutarate-dependent dioxygenase, an activity associated with histone demethylation in other organisms, and mutant plants show defects in multiple aspects of the Arabidopsis epigenome. To investigate its primary molecular function we identified the Arabidopsis FLOWERING LOCUS C (FLC) as a direct target and found icu11 disrupted the cold-induced, Polycomb-mediated silencing underlying vernalization. icu11 prevented reduction in H3K36me3 levels normally seen during the early cold phase, supporting a role for ICU11 in H3K36me3 demethylation. This was coincident with an attenuation of H3K27me3 at the internal nucleation site in FLC, and reduction in H3K27me3 levels across the body of the gene after plants were returned to the warm. Thus, ICU11 is required for the cold-induced epigenetic switching between the mutually exclusive chromatin states at FLC, from the active H3K36me3 state to the silenced H3K27me3 state. These data support the importance of physical coupling of histone modification activities to promote epigenetic switching between opposing chromatin states.


Assuntos
Arabidopsis/metabolismo , Epigênese Genética , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Histonas/genética , Histonas/metabolismo , Metilação , Ligação Proteica , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
3.
PLoS Genet ; 16(5): e1008796, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32428001

RESUMO

Sex differences in the incidence and progression of many liver diseases, including liver fibrosis and hepatocellular carcinoma, are associated with sex-biased hepatic expression of hundreds of genes. This sexual dimorphism is largely determined by the sex-specific pattern of pituitary growth hormone secretion, which controls a transcriptional regulatory network operative in the context of sex-biased and growth hormone-regulated chromatin states. Histone H3K27-trimethylation yields a major sex-biased repressive chromatin mark deposited at many strongly female-biased genes in male mouse liver, but not at male-biased genes in female liver, and is catalyzed by polycomb repressive complex-2 through its homologous catalytic subunits, Ezh1 and Ezh2. Here, we used Ezh1-knockout mice with a hepatocyte-specific knockout of Ezh2 to investigate the sex bias of liver H3K27-trimethylation and its functional role in regulating sex-differences in the liver. Combined hepatic Ezh1/Ezh2 deficiency led to a significant loss of sex-biased gene expression, particularly in male liver, where many female-biased genes were increased in expression while male-biased genes showed decreased expression. The associated loss of H3K27me3 marks, and increases in the active enhancer marks H3K27ac and H3K4me1, were also more pronounced in male liver. Further, Ezh1/Ezh2 deficiency in male liver, and to a lesser extent in female liver, led to up regulation of many genes linked to liver fibrosis and liver cancer, which may contribute to the observed liver pathologies and the increased sensitivity of these mice to hepatotoxin exposure. Thus, Ezh1/Ezh2-catalyzed H3K27-trimethyation regulates sex-dependent genetic programs in liver metabolism and liver fibrosis through its sex-dependent effects on the epigenome, and may thereby determine the sex-bias in liver disease susceptibility.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/genética , Cirrose Hepática/genética , Fígado/metabolismo , Complexo Repressor Polycomb 2/genética , Animais , Modelos Animais de Doenças , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Técnicas de Inativação de Genes , Histonas/metabolismo , Cirrose Hepática/metabolismo , Masculino , Metilação , Camundongos , Complexo Repressor Polycomb 2/metabolismo , Análise de Sequência de RNA , Caracteres Sexuais
4.
Life Sci ; 253: 117626, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32247002

RESUMO

AIMS: Postoperative cognitive dysfunction (POCD) is a common postoperative complication that is associated with increased morbidity and mortality. However, the mechanism of pathogenesis of POCD still remains largely unknown. The aim of the study was to investigate the function and mechanism of lncRNA PCAI in POCD. MATERIALS AND METHODS: Knockdown and overexpression studies were performed to analyze the function of lncRNA PCAI in cultured BV-2 cell lines treated with LPS to mimic the neuroinflammation. Real-time PCR, western blot, ELISA were used to determine the expression level of inflammation markers. Rescue experiment was performed to prove the relationship between PCAI and SUZ12. RESULTS: We found that the expression of lncRNA PCAI was decreased with the increasing concentrations of LPS. Knockdown of lncRNA PCAI inhibited the cell death rates and attenuated the cell inflammation via ELISA and real-time PCR. Besides, downregulated of lncRNA PCAI can protect the mitochondrial function via membrane potential assay. Overexpression of lncRNA PCAI can promote the cell death and inflammation response induced by LPS. We also provided mechanism study about lncRNA PCAI that negatively regulating SUZ12. Rescue experiment also verified the results. CONCLUSION: We performed comprehensive study of functional analysis of lncRNA PCAI in POCD and proved its mechanism, which negatively regulate SUZ12. Our study provided new clues for the clinical intervention and targets for POCD.


Assuntos
Disfunção Cognitiva/etiologia , Hipocampo/metabolismo , Inflamação/metabolismo , Complicações Cognitivas Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/prevenção & controle , RNA Longo não Codificante/genética , Animais , Linhagem Celular , Regulação da Expressão Gênica , Técnicas de Silenciamento de Genes , Inflamação/patologia , Camundongos , Membranas Mitocondriais/metabolismo , Complexo Repressor Polycomb 2/genética , Substâncias Protetoras/metabolismo , Substâncias Protetoras/farmacologia
5.
Am J Hum Genet ; 106(5): 596-610, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32243864

RESUMO

Weaver syndrome (WS), an overgrowth/intellectual disability syndrome (OGID), is caused by pathogenic variants in the histone methyltransferase EZH2, which encodes a core component of the Polycomb repressive complex-2 (PRC2). Using genome-wide DNA methylation (DNAm) data for 187 individuals with OGID and 969 control subjects, we show that pathogenic variants in EZH2 generate a highly specific and sensitive DNAm signature reflecting the phenotype of WS. This signature can be used to distinguish loss-of-function from gain-of-function missense variants and to detect somatic mosaicism. We also show that the signature can accurately classify sequence variants in EED and SUZ12, which encode two other core components of PRC2, and predict the presence of pathogenic variants in undiagnosed individuals with OGID. The discovery of a functionally relevant signature with utility for diagnostic classification of sequence variants in EZH2, EED, and SUZ12 supports the emerging paradigm shift for implementation of DNAm signatures into diagnostics and translational research.


Assuntos
Anormalidades Múltiplas/genética , Hipotireoidismo Congênito/genética , Anormalidades Craniofaciais/genética , Metilação de DNA , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Deformidades Congênitas da Mão/genética , Deficiência Intelectual/genética , Mutação , Complexo Repressor Polycomb 2/genética , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Lactente , Masculino , Mosaicismo , Mutação de Sentido Incorreto/genética , Reprodutibilidade dos Testes , Adulto Jovem
6.
Mol Cell Biol ; 40(11)2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-32179551

RESUMO

Polycomb repressive complex 2 (PRC2) catalyzes methylation of histone H3 at lysine 27 (H3K27) in genomic regions of most eukaryotes and is critical for maintenance of the associated transcriptional repression. However, the mechanisms that shape the distribution of H3K27 methylation, such as recruitment of PRC2 to chromatin and/or stimulation of PRC2 activity, are unclear. Here, using a forward genetic approach in the model organism Neurospora crassa, we identified two alleles of a gene, NCU04278, encoding an unknown PRC2 accessory subunit (PAS). Loss of PAS resulted in losses of H3K27 methylation concentrated near the chromosome ends and derepression of a subset of associated subtelomeric genes. Immunoprecipitation followed by mass spectrometry confirmed reciprocal interactions between PAS and known PRC2 subunits, and sequence similarity searches demonstrated that PAS is not unique to N. crassa PAS homologs likely influence the distribution of H3K27 methylation and underlying gene repression in a variety of fungal lineages.


Assuntos
Histonas/metabolismo , Neurospora crassa/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Proteínas de Protozoários/metabolismo , Deleção de Genes , Lisina/metabolismo , Metilação , Neurospora crassa/genética , Complexo Repressor Polycomb 2/genética , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Proteínas de Protozoários/genética
7.
Nat Genet ; 52(3): 264-272, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32094912

RESUMO

Lineage-specific gene expression is modulated by a balance between transcriptional activation and repression during animal development. Knowledge about enhancer-centered transcriptional activation has advanced considerably, but silencers and their roles in normal development remain poorly understood. Here, we performed chromatin interaction analyses of Polycomb repressive complex 2 (PRC2), a key inducer of transcriptional gene silencing, to uncover silencers, their molecular identity and associated chromatin connectivity. Systematic analysis of cis-regulatory silencer elements reveals their chromatin features and gene-targeting specificity. Deletion of certain PRC2-bound silencers in mice results in transcriptional derepression of their interacting genes and pleiotropic developmental phenotypes, including embryonic lethality. While some PRC2-bound elements function as silencers in pluripotent cells, they can transition into active tissue-specific enhancers during development, highlighting their regulatory versatility. Our study characterizes the molecular profile of silencers and their associated chromatin architectures, and suggests the possibility of targeted reactivation of epigenetically silenced genes.


Assuntos
Cromatina/genética , Elementos Facilitadores Genéticos/genética , Inativação Gênica , Complexo Repressor Polycomb 2/metabolismo , Proteínas Repressoras/metabolismo , Elementos Silenciadores Transcricionais/genética , Animais , Linhagem Celular , Feminino , Masculino , Camundongos , Camundongos Knockout , Células-Tronco Embrionárias Murinas , Especificidade de Órgãos , Fenótipo , Complexo Repressor Polycomb 2/genética , Proteínas Repressoras/genética , Ativação Transcricional
8.
Mol Cell ; 77(6): 1265-1278.e7, 2020 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-31959557

RESUMO

Diverse accessory subunits are involved in the recruitment of polycomb repressive complex 2 (PRC2) to CpG island (CGI) chromatin. Here we report the crystal structure of a SUZ12-RBBP4 complex bound to fragments of the accessory subunits PHF19 and JARID2. Unexpectedly, this complex adopts a dimeric structural architecture, accounting for PRC2 self-association that has long been implicated. The intrinsic PRC2 dimer is formed via domain swapping involving RBBP4 and the unique C2 domain of SUZ12. MTF2 and PHF19 associate with PRC2 at around the dimer interface and stabilize the dimer. Conversely, AEBP2 binding results in a drastic movement of the C2 domain, disrupting the intrinsic PRC2 dimer. PRC2 dimerization enhances CGI DNA binding by PCLs in pairs in vitro, reminiscent of the widespread phenomenon of transcription factor dimerization in active transcription. Loss of PRC2 dimerization impairs histone H3K27 trimethylation (H3K27me3) on chromatin at developmental gene loci in mouse embryonic stem cells.


Assuntos
Cromatina/metabolismo , Ilhas de CpG , Metilação de DNA , Histonas/metabolismo , Complexo Repressor Polycomb 2/química , Multimerização Proteica , Animais , Diferenciação Celular , Cromatina/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Histonas/genética , Humanos , Camundongos , Camundongos Knockout , Células-Tronco Embrionárias Murinas/citologia , Células-Tronco Embrionárias Murinas/metabolismo , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo , Complexo Repressor Polycomb 2/fisiologia , Conformação Proteica , Proteína 4 de Ligação ao Retinoblastoma/genética , Proteína 4 de Ligação ao Retinoblastoma/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
9.
Chem Pharm Bull (Tokyo) ; 68(1): 58-63, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31685780

RESUMO

Polycomb repressive complex 2 (PRC2) is an attractive drug target for anti-cancer treatment. Among the three core subunits (EZH2, EED and SUZ12) of PRC2, EZH2 is the catalytic subunit that methylates histone H3 lysine 27 (H3K27), while EED is the regulatory subunit. Besides the small-molecule inhibitors of EZH2, those targeting the protein-protein interaction (PPI) between EZH2 and EED have also been reported. Here, for the first time, we have identified the key residues that contributed most to the EED-EZH2 binding affinity by molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) calculations based on the 200 ns molecular dynamics simulation. Moreover, we report the identification of two novel and potent small-molecule inhibitors (35 and 49) of EZH2-EED interaction (bottom interaction surface) by virtual screening and biological evaluations. Binding modes of the two identified molecules with EED were probed by molecular docking. Additionally, 35 and 49 displayed cellular antiproliferative activity against diffuse large B-cell lymphoma (DLBCL) cancer cell line Toledo whose cell growth was driven by aberrant PRC2 activity. Our findings have provided structural insights for the design of novel EZH2-EED interaction inhibitors to regulate the activity of PRC2 complex.


Assuntos
Simulação de Acoplamento Molecular , Complexo Repressor Polycomb 2/metabolismo , Bibliotecas de Moléculas Pequenas/química , Sítios de Ligação , Ligação Competitiva , Domínio Catalítico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desenho de Fármacos , Humanos , Complexo Repressor Polycomb 2/antagonistas & inibidores , Complexo Repressor Polycomb 2/genética , Domínios e Motivos de Interação entre Proteínas/efeitos dos fármacos , Subunidades Proteicas/antagonistas & inibidores , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Bibliotecas de Moléculas Pequenas/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia
10.
J Mol Biol ; 432(4): 897-912, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-31866294

RESUMO

USP7 is a deubiquitinase that regulates many diverse cellular processes, including tumor suppression, epigenetics, and genome stability. Several substrates, including GMPS, UHRF1, and ICP0, were shown to bear a specific KxxxK motif that interacts within the C-terminal region of USP7. We identified a similar motif in Enhancer of Zeste 2 (EZH2), the histone methyltransferase found within Polycomb Repressive Complex 2 (PRC2). PRC2 is responsible for the methylation of Histone 3 Lys27 (H3K27) leading to gene silencing. GST pull-down and coimmunoprecipitation experiments showed that USP7 interacts with EZH2. We determined the structural basis of interaction between USP7 and EZH2 and identified residues mediating the interaction. Mutations in these critical residues disrupted the interaction between USP7 and EZH2. Furthermore, USP7 silencing and knockout experiments showed decreased EZH2 levels in HCT116 carcinoma cells. Finally, we demonstrated decreased H3K27Me3 levels in HCT116 USP7 knockout cells. These results indicate that USP7 interacts with EZH2 and regulates both its stability and function.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Peptidase 7 Específica de Ubiquitina/metabolismo , Linhagem Celular Tumoral , Eletroforese em Gel de Poliacrilamida , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Inativação Gênica/fisiologia , Células HCT116 , Humanos , Imunoprecipitação , Complexo Repressor Polycomb 2/genética , Estabilidade Proteica , Peptidase 7 Específica de Ubiquitina/genética , Ubiquitinação/genética , Ubiquitinação/fisiologia
11.
Cell Mol Biol (Noisy-le-grand) ; 65(7): 138-145, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31880532

RESUMO

It was to study the influence of Wilms tumor suppressor gene (WT1) on ovarian granular cells (GCs) in mice, and the molecular mechanism involved. LV-WT1 short hairpin ribonucleic acid (shRNA) vector was used to downregulate WT1 expression in granular cells (GCs). The effects of WTI on proliferation and apoptosis of GCs were investigated. Western blot and qRT-PCR were used to assay the mRNA and protein expressions of Bax/bcl-2 in GCs transfected with LV-WT1-RNAi. The expression levels of SUZ12, Wnt5a, Wnt11, Wnt4, Wnt3a, Wnt2 mRNA in GCs were also determined. LV-WT1-RNAi significantly reduced WT1 expression, increased apoptosis and inhibited proliferation of GCs. The inhibition of WT1 had no significant effect on the expression of bcl-2 in GCs. The expressions of Wnt2, Wnt4 and Wnt5a were augmented in WT1-knockdown GCs, relative to non-transfected cells. WT1 activation is necessary for maintaining early survival of GCs in follicles via activation of the Wnt/ß-catenin signal pathway.


Assuntos
Células da Granulosa/metabolismo , Proteínas WT1/metabolismo , beta Catenina/metabolismo , Animais , Apoptose/genética , Apoptose/fisiologia , Proliferação de Células/genética , Proliferação de Células/fisiologia , Feminino , Citometria de Fluxo , Imunofluorescência , Imuno-Histoquímica , Camundongos , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas WT1/genética , Proteínas Wnt/genética , Proteínas Wnt/metabolismo , Via de Sinalização Wnt/genética , Via de Sinalização Wnt/fisiologia , Proteína Wnt-5a/genética , Proteína Wnt-5a/metabolismo , Proteína Wnt3A/genética , Proteína Wnt3A/metabolismo , Proteína Wnt4/genética , Proteína Wnt4/metabolismo , beta Catenina/genética
12.
Epigenetics Chromatin ; 12(1): 78, 2019 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-31856907

RESUMO

BACKGROUND: While the role of Polycomb group protein-mediated "cell memory" is well established in developmental contexts, little is known about their role in adult tissues and in particular in post-mitotic cells. Emerging evidence assigns a pivotal role in cell plasticity and adaptation. PRC2-Ezh1α/ß signaling pathway from cytoplasm to chromatin protects skeletal muscle cells from oxidative stress. However, detailed mechanisms controlling degradation of cytoplasmic Ezh1ß and assembly of canonical PRC2-Ezh1α repressive complex remain to be clarified. RESULTS: Here, we report NEDD4 ubiquitin E3 ligase, as key regulator of Ezh1ß. In addition, we report that ubiquitination and degradation of Ezh1ß is controlled by another layer of regulation, that is, one specific phosphorylation of serine 560 located at Ezh1ß-specific C terminal. Finally, we demonstrate that also Ezh1α needs to be stabilized under stress condition and this stabilization process requires decreased association pattern between another E3 ubiquitin ligase HUWE1. CONCLUSIONS: Together, these results shed light on key components that regulate PRC2-Ezh1α/ß pathway to direct modulation of epigenome plasticity and transcriptional output in skeletal muscle cells.


Assuntos
Ubiquitina-Proteína Ligases Nedd4/metabolismo , Estresse Oxidativo , Transdução de Sinais , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Linhagem Celular , Histonas/metabolismo , Peróxido de Hidrogênio/farmacologia , Camundongos , Mioblastos Esqueléticos/citologia , Mioblastos Esqueléticos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Complexo Repressor Polycomb 2/química , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo , Ubiquitinação
13.
Epigenetics Chromatin ; 12(1): 76, 2019 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-31856916

RESUMO

BACKGROUND: Neural tube defects (NTDs) are severe, common birth defects that result from failure of normal neural tube closure during early embryogenesis. Accumulating strong evidence indicates that genetic factors contribute to NTDs etiology, among them, HOX genes play a key role in neural tube closure. Although abnormal HOX gene expression can lead to NTDs, the underlying pathological mechanisms have not fully been understood. METHOD: We detected that H3K27me3 and expression of the Hox genes in a retinoic acid (RA) induced mouse NTDs model on E8.5, E9.5 and E10.5 using RNA-sequencing and chromatin immunoprecipitation sequencing assays. Furthermore, we quantified 10 Hox genes using NanoString nCounter in brain tissue of fetuses with 39 NTDs patients including anencephaly, spina bifida, hydrocephaly and encephalocele. RESULTS: Here, our results showed differential expression in 26 genes with a > 20-fold change in the level of expression, including 10 upregulated Hox genes. RT-qPCR revealed that these 10 Hox genes were all upregulated in RA-induced mouse NTDs as well as RA-treated embryonic stem cells (ESCs). Using ChIP-seq assays, we demonstrate that a decrease in H3K27me3 level upregulates the expression of Hox cluster A-D in RA-induced mouse NTDs model on E10.5. Interestingly, RA treatment led to attenuation of H3K27me3 due to cooperate between UTX and Suz12, affecting Hox gene regulation. Further analysis, in human anencephaly cases, upregulation of 10 HOX genes was observed, along with aberrant levels of H3K27me3. Notably, HOXB4, HOXC4 and HOXD1 expression was negatively correlated with H3K27me3 levels. CONCLUSION: Our results indicate that abnormal HOX gene expression induced by aberrant H3K27me3 levels may be a risk factor for NTDs and highlight the need for further analysis of genome-wide epigenetic modification in NTDs.


Assuntos
Histonas/metabolismo , Proteínas de Homeodomínio/metabolismo , Defeitos do Tubo Neural/patologia , Anencefalia/metabolismo , Anencefalia/patologia , Animais , Modelos Animais de Doenças , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Histona Desmetilases/antagonistas & inibidores , Histona Desmetilases/metabolismo , Proteínas de Homeodomínio/genética , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Defeitos do Tubo Neural/induzido quimicamente , Complexo Repressor Polycomb 2/antagonistas & inibidores , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Tretinoína/toxicidade , Regulação para Cima/efeitos dos fármacos
14.
Am J Med Genet C Semin Med Genet ; 181(4): 519-531, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31724824

RESUMO

The EZH2, EED, and SUZ12 genes encode proteins that comprise core components of the polycomb repressive complex 2 (PRC2), an epigenetic "writer" with H3K27 methyltransferase activity, catalyzing the addition of up to three methyl groups on histone 3 at lysine residue 27 (H3K27). Partial loss-of-function variants in genes encoding the EZH2 and EED subunits of the complex lead to overgrowth, macrocephaly, advanced bone age, variable intellectual disability, and distinctive facial features. EZH2-associated overgrowth, caused by constitutional heterozygous mutations within Enhancer of Zeste homologue 2 (EZH2), has a phenotypic spectrum ranging from tall stature without obvious intellectual disability or dysmorphic features to classical Weaver syndrome (OMIM #277590). EED-associated overgrowth (Cohen-Gibson syndrome; OMIM #617561) is caused by germline heterozygous mutations in Embryonic Ectoderm Development (EED), and manifests overgrowth and intellectual disability (OGID), along with other features similar to Weaver syndrome. Most recently, rare coding variants in SUZ12 have also been described that present with clinical characteristics similar to the previous two syndromes. Here we review the PRC2 complex and clinical syndromes of OGID associated with core components EZH2, EED, and SUZ12.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/genética , Transtornos do Crescimento/genética , Fenótipo , Complexo Repressor Polycomb 2/genética , Humanos , Síndrome
15.
Nat Commun ; 10(1): 5051, 2019 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-31699991

RESUMO

The oncogenic fusion protein AML1-ETO retains the ability of AML1 to interact with the enhancer core DNA sequences, but blocks AML1-dependent transcription. Previous studies have shown that post-translational modification of AML1-ETO may play a role in its regulation. Here we report that AML1-ETO-positive patients, with high histone lysine methyltransferase Enhancer of zeste homolog 1 (EZH1) expression, show a worse overall survival than those with lower EZH1 expression. EZH1 knockdown impairs survival and proliferation of AML1-ETO-expressing cells in vitro and in vivo. We find that EZH1 WD domain binds to the AML1-ETO NHR1 domain and methylates AML1-ETO at lysine 43 (Lys43). This requires the EZH1 SET domain, which augments AML1-ETO-dependent repression of tumor suppressor genes. Loss of Lys43 methylation by point mutation or domain deletion impairs AML1-ETO-repressive activity. These findings highlight the role of EZH1 in non-histone lysine methylation, indicating that cooperation between AML1-ETO and EZH1 and AML1-ETO site-specific lysine methylation promote AML1-ETO transcriptional repression in leukemia.


Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/genética , Leucemia Mieloide Aguda/genética , Proteínas de Fusão Oncogênica/genética , Complexo Repressor Polycomb 2/genética , Proteína 1 Parceira de Translocação de RUNX1/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células/genética , Sobrevivência Celular/genética , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Células Jurkat , Leucemia Mieloide Aguda/metabolismo , Metilação , Camundongos , Camundongos Nus , Mutação , Transplante de Neoplasias , Proteínas de Fusão Oncogênica/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Prognóstico , RNA Mensageiro/metabolismo , Proteína 1 Parceira de Translocação de RUNX1/metabolismo , Células THP-1
16.
Am J Med Genet C Semin Med Genet ; 181(4): 532-547, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31736240

RESUMO

The Polycomb repressive complex 2 is an epigenetic writer and recruiter with a role in transcriptional silencing. Constitutional pathogenic variants in its component proteins have been found to cause two established overgrowth syndromes: Weaver syndrome (EZH2-related overgrowth) and Cohen-Gibson syndrome (EED-related overgrowth). Imagawa et al. (2017) initially reported a singleton female with a Weaver-like phenotype with a rare coding SUZ12 variant-the same group subsequently reported two additional affected patients. Here we describe a further 10 patients (from nine families) with rare heterozygous SUZ12 variants who present with a Weaver-like phenotype. We report four frameshift, two missense, one nonsense, and two splice site variants. The affected patients demonstrate variable pre- and postnatal overgrowth, dysmorphic features, musculoskeletal abnormalities and developmental delay/intellectual disability. Some patients have genitourinary and structural brain abnormalities, and there may be an association with respiratory issues. The addition of these 10 patients makes a compelling argument that rare pathogenic SUZ12 variants frequently cause overgrowth, physical abnormalities, and abnormal neurodevelopmental outcomes in the heterozygous state. Pathogenic SUZ12 variants may be de novo or inherited, and are sometimes inherited from a mildly-affected parent. Larger samples sizes will be needed to elucidate whether one or more clinically-recognizable syndromes emerge from different variant subtypes.


Assuntos
Transtornos do Crescimento/genética , Fenótipo , Complexo Repressor Polycomb 2/genética , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/genética , Masculino , Mutação
17.
Diagn Pathol ; 14(1): 110, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31615558

RESUMO

BACKGROUND: Low-grade endometrial stromal sarcoma (ESS) is rare mesenchymal neoplasm, recently specified as harboring JAZF1-SUZ12 rearrangement. Typical JAZF1-SUZ12 ESS is slow growing, in which high uptake of fluorodeoxyglucose (FDG) on positron emission tomography (PET) and subserosal masses are quite unusual. CASE PRESENTATION: A 69-year-old Japanese woman complained of urinary incontinence. Pelvic magnetic resonance imaging showed uterine lesions composed of (1) a 9 × 8 × 7-cm mass protruding from the right-anterior wall, (2) a 4.5-cm mass attached to the right-posterior wall, and (3) a 6.5-cm intramural mass in the fundus. FDG-PET demonstrated maximum standardized uptake value of 13.28 confined to the two subserosal masses (1 & 2) in contrast to no uptake of the intramural mass (3). She was diagnosed with a high-grade uterine sarcoma concomitant with leiomyomas and underwent total hysterectomy with bilateral salpingo-oophorectomy and pelvic lymphadenectomy. The removed uterus had three tumors-two in the right-anterior and right-posterior subserosa, respectively, and the remaining in the fundal myometrium. Microscopically, the three tumors shared morphologic features characterized by neoplastic cells similar to proliferative-phase endometrial stromal cells, in which neither round-cell component, pleomorphism, nor high mitotic activity was recognized. Nuclear cyclin D1 immunostaining was identified 50% of neoplastic cells in the two subserosal tumors (1 &2) whereas < 1% positive cells in the intramural component (3). Reverse transcriptase-polymerase chain reaction showed the same-sized electrophoretic bands indicating JAZF1-SUZ12 gene fusion shared by the three uterine tumors and a focal tumor extension into the extrauterine vein. The patient is alive without evidence of recurrence at 14 months after surgery. CONCLUSIONS: Pathologists and clinicians should not exclude the possibility of JAZF1-SUZ12 ESS even when uterine subserosal masses demonstrate extraordinary FDG uptake on PET. Molecular analysis is helpful for diagnostic confirmation of JAZF1-SUZ12 ESS with a complex growth pattern.


Assuntos
Proteínas Correpressoras/genética , Proteínas de Ligação a DNA/genética , Recidiva Local de Neoplasia/genética , Complexo Repressor Polycomb 2/genética , Sarcoma do Estroma Endometrial/genética , Idoso , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/patologia , Feminino , Humanos , Hibridização in Situ Fluorescente/métodos , Proteínas de Neoplasias/genética , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/patologia , Sarcoma do Estroma Endometrial/diagnóstico , Sarcoma do Estroma Endometrial/patologia
18.
Cancer Sci ; 110(12): 3695-3707, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31571328

RESUMO

Polycomb repressive complex 2 (PRC2) components, EZH2 and its homolog EZH1, and PI3K/Akt signaling pathway are focal points as therapeutic targets for multiple myeloma. However, the exact crosstalk between their downstream targets remains unclear. We herein elucidated some epigenetic interactions following Akt inhibition and demonstrated the efficacy of the combined inhibition of Akt and PRC2. We found that TAS-117, a potent and selective Akt inhibitor, downregulated EZH2 expression at the mRNA and protein levels via interference with the Rb-E2F pathway, while EZH1 was compensatively upregulated to maintain H3K27me3 modifications. Consistent with these results, the dual EZH2/EZH1 inhibitor, UNC1999, but not the selective EZH2 inhibitor, GSK126, synergistically enhanced TAS-117-induced cytotoxicity and provoked myeloma cell apoptosis. RNA-seq analysis revealed the activation of the FOXO signaling pathway after TAS-117 treatment. FOXO3/4 mRNA and their downstream targets were upregulated with the enhanced nuclear localization of FOXO3 protein after TAS-117 treatment. ChIP assays confirmed the direct binding of FOXO3 to EZH1 promoter, which was enhanced by TAS-117 treatment. Moreover, FOXO3 knockdown repressed EZH1 expression. Collectively, the present results reveal some molecular interactions between Akt signaling and epigenetic modulators, which emphasize the benefits of targeting PRC2 full activity and the Akt pathway as a therapeutic option for multiple myeloma.


Assuntos
Compostos Heterocíclicos com 3 Anéis/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Complexo Repressor Polycomb 2/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Sinergismo Farmacológico , Proteína Potenciadora do Homólogo 2 de Zeste/antagonistas & inibidores , Proteína Potenciadora do Homólogo 2 de Zeste/fisiologia , Proteína Forkhead Box O3/fisiologia , Humanos , Mieloma Múltiplo/patologia , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/fisiologia , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas c-akt/fisiologia , Piridonas/uso terapêutico
19.
Blood ; 134(16): 1323-1336, 2019 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-31492675

RESUMO

The polycomb repressive complex 2, with core components EZH2, SUZ12, and EED, is responsible for writing histone 3 lysine 27 trimethylation histone marks associated with gene repression. Analysis of sequence data from 419 T-cell acute lymphoblastic leukemia (T-ALL) cases demonstrated a significant association between SUZ12 and JAK3 mutations. Here we show that CRISPR/Cas9-mediated inactivation of Suz12 cooperates with mutant JAK3 to drive T-cell transformation and T-ALL development. Gene expression profiling integrated with ChIP-seq and ATAC-seq data established that inactivation of Suz12 led to increased PI3K/mammalian target of rapamycin (mTOR), vascular endothelial growth factor (VEGF), and WNT signaling. Moreover, a drug screen revealed that JAK3/Suz12 mutant leukemia cells were more sensitive to histone deacetylase (HDAC)6 inhibition than JAK3 mutant leukemia cells. Among the broad genome and gene expression changes observed on Suz12 inactivation, our integrated analysis identified the PI3K/mTOR, VEGF/VEGF receptor, and HDAC6/HSP90 pathways as specific vulnerabilities in T-ALL cells with combined JAK3 and SUZ12 mutations.


Assuntos
Transformação Celular Neoplásica/genética , Complexo Repressor Polycomb 2/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Transdução de Sinais/fisiologia , Animais , Humanos , Janus Quinase 3/genética , Camundongos , Mutação
20.
Mol Cell ; 76(3): 437-452.e6, 2019 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-31521505

RESUMO

Polycomb repressive complex 2 (PRC2) is composed of EED, SUZ12, and EZH1/2 and mediates mono-, di-, and trimethylation of histone H3 at lysine 27. At least two independent subcomplexes exist, defined by their specific accessory proteins: PRC2.1 (PCL1-3, EPOP, and PALI1/2) and PRC2.2 (AEBP2 and JARID2). We show that PRC2.1 and PRC2.2 share the majority of target genes in mouse embryonic stem cells. The loss of PCL1-3 is sufficient to evict PRC2.1 from Polycomb target genes but only leads to a partial reduction of PRC2.2 and H3K27me3. Conversely, disruption of PRC2.2 function through the loss of either JARID2 or RING1A/B is insufficient to completely disrupt targeting of SUZ12 by PCLs. Instead, the combined loss of both PRC2.1 and PRC2.2 is required, leading to the global mislocalization of SUZ12. This supports a model in which the specific accessory proteins within PRC2.1 and PRC2.2 cooperate to direct H3K27me3 via both synergistic and independent mechanisms.


Assuntos
Cromatina/metabolismo , Histonas/metabolismo , Células-Tronco Embrionárias Murinas/metabolismo , Complexo Repressor Polycomb 2/metabolismo , Processamento de Proteína Pós-Traducional , Animais , Sítios de Ligação , Linhagem Celular Tumoral , Cromatina/genética , Humanos , Metilação , Camundongos , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Complexo Repressor Polycomb 2/genética , Ligação Proteica , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
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