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1.
Anticancer Res ; 41(7): 3597-3606, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34230156

RESUMO

AIM: To evaluate the association between bromodomain-containing protein 4 (BRD4) expression and clinicopathological factors and prognosis in human breast cancer specimens. PATIENTS AND METHODS: We used tissue microarrays constructed from samples of patients (n=183) who underwent surgery. We validated the association between BRD4 expression and prognosis in solid tumours, including breast cancer, using The Cancer Genome Atlas (TCGA) database. RESULTS: Immunohistochemical staining showed that BRD4 was widely distributed in breast cancer tissues. BRD4 was strongly expressed in 19.7% of patients but BRD4 staining intensity was not correlated with other clinicopathological factors. Most importantly, patients with a strong BRD4 expression had a significantly longer disease-specific survival than those with a weak BRD4 expression (100.0% vs. 91.3% at 5 years, p=0.027). mRNA expression analysis showed similar results (91.2% vs. 80.2% at 6 years, p=0.047). CONCLUSION: Strong BRD4 expression was associated with a significantly better prognosis in breast cancer tumours.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proteínas de Ciclo Celular/metabolismo , Fatores de Transcrição/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Pessoa de Meia-Idade , Prognóstico , RNA Mensageiro/metabolismo
2.
Nat Commun ; 12(1): 4170, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34234130

RESUMO

Genome organization is driven by forces affecting transcriptional state, but the relationship between transcription and genome architecture remains unclear. Here, we identified the Drosophila transcription factor Motif 1 Binding Protein (M1BP) in physical association with the gypsy chromatin insulator core complex, including the universal insulator protein CP190. M1BP is required for enhancer-blocking and barrier activities of the gypsy insulator as well as its proper nuclear localization. Genome-wide, M1BP specifically colocalizes with CP190 at Motif 1-containing promoters, which are enriched at topologically associating domain (TAD) borders. M1BP facilitates CP190 chromatin binding at many shared sites and vice versa. Both factors promote Motif 1-dependent gene expression and transcription near TAD borders genome-wide. Finally, loss of M1BP reduces chromatin accessibility and increases both inter- and intra-TAD local genome compaction. Our results reveal physical and functional interaction between CP190 and M1BP to activate transcription at TAD borders and mediate chromatin insulator-dependent genome organization.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Repressoras/metabolismo , Fatores de Transcrição/metabolismo , Ativação Transcricional , Animais , Animais Geneticamente Modificados , Linhagem Celular , Núcleo Celular/metabolismo , Cromatina/genética , Cromatina/metabolismo , Sequenciamento de Cromatina por Imunoprecipitação , Proteínas de Drosophila/genética , Técnicas de Silenciamento de Genes , Genoma de Inseto , Elementos Isolantes/genética , Masculino , Proteínas Associadas aos Microtúbulos/genética , Proteínas Nucleares/genética , Regiões Promotoras Genéticas/genética , RNA-Seq , Proteínas Repressoras/genética , Fatores de Transcrição/genética
3.
Int J Mol Sci ; 22(11)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34199904

RESUMO

Nutrition determines our health, both directly and indirectly. Consumed foods affect the functioning of individual organs as well as entire systems, e.g., the cardiovascular system. There are many different diets, but universal guidelines for proper nutrition are provided in the WHO healthy eating pyramid. According to the latest version, plant products should form the basis of our diet. Many groups of plant compounds with a beneficial effect on human health have been described. Such groups include anthocyanins and iridoids, for which it has been proven that their consumption may lead to, inter alia, antioxidant, cholesterol and lipid-lowering, anti-obesity and anti-diabetic effects. Transcription factors directly affect a number of parameters of cell functions and cellular metabolism. In the context of lipid and cholesterol metabolism, five particularly important transcription factors can be distinguished: liver X receptor (LXR), peroxisome proliferator-activated receptor-α (PPAR-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT/enhancer binding protein α (C/EBPα) and sterol regulatory element-binding protein 1c (SREBP-1c). Both anthocyanins and iridoids may alter the expression of these transcription factors. The aim of this review is to collect and systematize knowledge about the impact of anthocyanins and iridoids on transcription factors crucial for lipid and cholesterol homeostasis.


Assuntos
Antocianinas/farmacologia , Colesterol/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Homeostase , Iridoides/farmacologia , Lipídeos/análise , Fatores de Transcrição/metabolismo , Animais , Humanos , Metabolismo dos Lipídeos , Fatores de Transcrição/genética
4.
Int J Mol Sci ; 22(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200125

RESUMO

Plants face a more volatile environment than other organisms because of their immobility, and they have developed highly efficient mechanisms to adapt to stress conditions. Transcription factors, as an important part of the adaptation process, are activated by different signals and are responsible for the expression of stress-responsive genes. MYB transcription factors, as one of the most widespread transcription factor families in plants, participate in plant development and responses to stresses by combining with MYB cis-elements in promoters of target genes. MYB transcription factors have been extensively studied and have proven to be critical in the biosynthesis of secondary metabolites in plants, including anthocyanins, flavonols, and lignin. Multiple studies have now shown that MYB proteins play diverse roles in the responses to abiotic stresses, such as drought, salt, and cold stresses. However, the regulatory mechanism of MYB proteins in abiotic stresses is still not well understood. In this review, we will focus mainly on the function of Arabidopsis MYB transcription factors in abiotic stresses, especially how MYB proteins participate in these stress responses. We also pay attention to how the MYB proteins are regulated in these processes at both the transcript and protein levels.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Secas , Regulação da Expressão Gênica de Plantas , Estresse Fisiológico , Fatores de Transcrição/metabolismo , Proteínas de Arabidopsis/genética , Fatores de Transcrição/genética
5.
Int J Mol Sci ; 22(11)2021 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-34200497

RESUMO

Left ventricular (LV) heart failure (HF) is a significant and increasing cause of death worldwide. HF is characterized by myocardial remodeling and excessive fibrosis. Transcriptional co-activator Yes-associated protein (Yap), the downstream effector of HIPPO signaling pathway, is an essential factor in cardiomyocyte survival; however, its status in human LV HF is not entirely elucidated. Here, we report that Yap is elevated in LV tissue of patients with HF, and is associated with down-regulation of its upstream inhibitor HIPPO component large tumor suppressor 1 (LATS1) activation as well as upregulation of the fibrosis marker connective tissue growth factor (CTGF). Applying the established profibrotic combined stress of TGFß and hypoxia to human ventricular cardiac fibroblasts in vitro increased Yap protein levels, down-regulated LATS1 activation, increased cell proliferation and collagen I production, and decreased ribosomal protein S6 and S6 kinase phosphorylation, a hallmark of mTOR activation, without any significant effect on mTOR and raptor protein expression or phosphorylation of mTOR or 4E-binding protein 1 (4EBP1), a downstream effector of mTOR pathway. As previously reported in various cell types, TGFß/hypoxia also enhanced cardiac fibroblast Akt and ERK1/2 phosphorylation, which was similar to our observation in LV tissues from HF patients. Further, depletion of Yap reduced TGFß/hypoxia-induced cardiac fibroblast proliferation and Akt phosphorylation at Ser 473 and Thr308, without any significant effect on TGFß/hypoxia-induced ERK1/2 activation or reduction in S6 and S6 kinase activities. Taken together, these data demonstrate that Yap is a mediator that promotes human cardiac fibroblast proliferation and suggest its possible contribution to remodeling of the LV, opening the door to further studies to decipher the cell-specific roles of Yap signaling in human HF.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proliferação de Células , Insuficiência Cardíaca/patologia , Miofibroblastos/patologia , Proteínas Serina-Treonina Quinases/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Estudos de Casos e Controles , Células Cultivadas , Feminino , Insuficiência Cardíaca/metabolismo , Humanos , Masculino , Miofibroblastos/metabolismo , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Fatores de Transcrição/genética , Ativação Transcricional
6.
Int J Mol Sci ; 22(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202438

RESUMO

The chloroplast is a semi-autonomous organelle with its own genome. The expression of chloroplast genes depends on both chloroplasts and the nucleus. Although many nucleus-encoded proteins have been shown to localize in chloroplasts and are essential for chloroplast gene expression, it is not clear whether transcription factors can regulate gene expression in chloroplasts. Here we report that the transcription factor NAC102 localizes in both chloroplasts and nucleus in Arabidopsis. Specifically, NAC102 localizes in chloroplast nucleoids. Yeast two-hybrid assay and co-immunoprecipitation assay suggested that NAC102 interacts with chloroplast RNA polymerases. Furthermore, overexpression of NAC102 in chloroplasts leads to reduced chloroplast gene expression and chlorophyll content, indicating that NAC102 functions as a repressor in chloroplasts. Our study not only revealed that transcription factors are new regulators of chloroplast gene expression, but also discovered that transcription factors can function in chloroplasts in addition to the canonical organelle nucleus.


Assuntos
Cloroplastos/genética , Cloroplastos/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Cloroplastos , Fatores de Transcrição/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Núcleo Celular , RNA Polimerases Dirigidas por DNA/metabolismo , Ligação Proteica , Transporte Proteico
7.
Int J Mol Sci ; 22(13)2021 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-34202673

RESUMO

Trichome formation in Arabidopsis is regulated by several key regulators, and plants hormones such as gibberellin, salicylic acid, jasmonic acid and cytokinins have been shown to regulate trichome formation by affecting the transcription or activities of the key regulators. We report here the identification of two abscisic acid (ABA) responsive genes, SMALLER TRICHOMES WITH VARIABLE BRANCHES (SVB) and SVB2 as trichome formation regulator genes in Arabidopsis. The expression levels of SVB and SVB2 were increased in response to ABA treatment, their expression levels were reduced in the ABA biosynthesis mutant aba1-5, and they have similar expression pattern. In addition to the trichome defects reported previously for the svb single mutant, we found that even though the trichome numbers were largely unaffected in both the svb and svb2 single mutants generate by using CRISPR/Cas9 gene editing, the trichome numbers were greatly reduced in the svb svb2 double mutants. On the other hand, trichome numbers were increased in SVB or SVB2 overexpression plants. RT-PCR results show that the expression of the trichome formation key regulator gene ENHANCER OF GLABRA3 (EGL3) was affected in the svb svb2 double mutants. Our results suggest that SVB and SVB2 are ABA responsive genes, and SVB and SVB2 function redundantly to regulate trichome formation in Arabidopsis.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Tricomas/metabolismo , Sequência de Aminoácidos , Arabidopsis/classificação , Proteínas de Arabidopsis/química , Mutação , Fenótipo , Filogenia , Desenvolvimento Vegetal , Transporte Proteico , Análise de Sequência de DNA , Fatores de Transcrição/metabolismo
8.
Int J Mol Sci ; 22(11)2021 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-34199719

RESUMO

Heart failure is a complex disease process with underlying aberrations in neurohormonal systems that promote dysregulated cellular signaling and gene transcription. Over the past 10 years, the advent of small-molecule inhibitors that target transcriptional machinery has demonstrated the importance of the bromodomain and extraterminal (BET) family of epigenetic reader proteins in regulating gene transcription in multiple mouse models of cardiomyopathy. BETs bind to acetylated histone tails and transcription factors to integrate disparate stress signaling networks into a defined gene expression program. Under myocardial stress, BRD4, a BET family member, is recruited to superenhancers and promoter regions of inflammatory and profibrotic genes to promote transcription elongation. Whole-transcriptome analysis of BET-dependent gene networks suggests a major role of nuclear-factor kappa b and transforming growth factor-beta in the development of cardiac fibrosis and systolic dysfunction. Recent investigations also suggest a prominent role of BRD4 in maintaining cardiomyocyte mitochondrial respiration under basal conditions. In this review, we summarize the data from preclinical heart failure studies that explore the role of BET-regulated transcriptional mechanisms and delve into landmark studies that define BET bromodomain-independent processes involved in cardiac homeostasis.


Assuntos
Regulação da Expressão Gênica , Insuficiência Cardíaca/genética , Fatores de Transcrição/metabolismo , Animais , Homeostase , Humanos , Modelos Biológicos , Miócitos Cardíacos/metabolismo
9.
BMC Plant Biol ; 21(1): 308, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193032

RESUMO

BACKGROUND: Rice (Oryza sativa L.) Chalkiness, the opaque part in the kernel endosperm formed by loosely piled starch and protein bodies. Chalkiness is a complex quantitative trait regulated by multiple genes and various environmental factors. Phytohormones play important roles in the regulation of chalkiness formation but the underlying molecular mechanism is still unclear at present. RESULTS: In this research, Xiangzaoxian24 (X24, pure line of indica rice with high-chalkiness) and its origin parents Xiangzaoxian11 (X11, female parent, pure line of indica rice with high-chalkiness) and Xiangzaoxian7 (X7, male parent, pure line of indica rice with low-chalkiness) were used as materials. The phenotype, physiological and biochemical traits combined with transcriptome analysis were conducted to illustrate the dynamic process and transcriptional regulation of rice chalkiness formation. Impressively, phytohormonal contents and multiple phytohormonal signals were significantly different in chalky caryopsis, suggesting the involvement of phytohormones, particularly ABA and auxin, in the regulation of rice chalkiness formation, through the interaction of multiple transcription factors and their downstream regulators. CONCLUSION: These results indicated that chalkiness formation is a dynamic process associated with multiple genes, forming a complex regulatory network in which phytohormones play important roles. These results provided informative clues for illustrating the regulatory mechanisms of chalkiness formation in rice.


Assuntos
Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oryza/genética , Oryza/fisiologia , Reguladores de Crescimento de Plantas/farmacologia , Transcrição Genética/efeitos dos fármacos , Endosperma/efeitos dos fármacos , Endosperma/metabolismo , Endosperma/ultraestrutura , Perfilação da Expressão Gênica , Ontologia Genética , Oryza/efeitos dos fármacos , Fenótipo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Reprodutibilidade dos Testes , Amido/metabolismo , Amido/ultraestrutura , Sacarose/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
10.
BMC Plant Biol ; 21(1): 305, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34193036

RESUMO

BACKGROUND: Natural variations derived from both evolutionary selection and genetic recombination, presume to have important functions to respond to various abiotic stresses, which could be used to improve drought tolerance via genomic selection. RESULTS: In the present study, the NAC-encoding gene of ZmNAC080308 was cloned and sequenced in 199 inbred lines in maize. Phylogenetic analysis showed that ZmNAC080308 is closely clusteredinto the same group with other well-known NAC genes responding to improve drought tolerance. In total, 86 SNPs and 47 InDels were identified in the generic region of ZmNAC080308, 19 of these variations were associated with GY (grain yield) in different environments. Nine variations in the 5'-UTR region of ZmNAC080308 are closely linked, they might regulate the gene expression and respond to improve GY under drought condition via Sp1-mediated transactivation. Two haplotypes (Hap1 and Hap2) identified in the, 5'-UTR region using the nine variations, and Hap2 containing insertion variants, exhibited 15.47 % higher GY under drought stress condition. Further, a functional marker was developed to predict the drought stress tolerance in a US maize inbred line panel. Lines carrying Hap2 exhibited > 10 % higher GY than those carrying Hap1 under drought stress condition. In Arabidopsis, overexpression ZmNAC080308 enhanced drought tolerance. CONCLUSIONS: ZmNAC080308 is an important gene responding to drought tolerance, a functional marker is developed for improving maize drought tolerance by selecting this gene.


Assuntos
Secas , Variação Genética , Proteínas de Plantas/genética , Sementes/crescimento & desenvolvimento , Estresse Fisiológico/genética , Zea mays/genética , Zea mays/fisiologia , Regiões 5' não Traduzidas/genética , Sequência de Aminoácidos , Arabidopsis/genética , Núcleo Celular/metabolismo , Regulação da Expressão Gênica de Plantas , Marcadores Genéticos , Genótipo , Desequilíbrio de Ligação/genética , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas , Polimorfismo de Nucleotídeo Único/genética , Plântula/metabolismo , Frações Subcelulares/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
11.
Int J Mol Sci ; 22(12)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203768

RESUMO

Mesembryanthemum crystallinum (common ice plant) is a halophyte species that has adapted to extreme conditions. In this study, we cloned a McHB7 transcription factor gene from the ice plant. The expression of McHB7 was significantly induced by 500 mM NaCl and it reached the peak under salt treatment for 7 days. The McHB7 protein was targeted to the nucleus. McHB7-overexpressing in ice plant leaves through Agrobacterium-mediated transformation led to 25 times more McHB7 transcripts than the non-transformed wild type (WT). After 500 mM NaCl treatment for 7 days, the activities of superoxide dismutase (SOD) and peroxidase (POD) and water content of the transgenic plants were higher than the WT, while malondialdehyde (MDA) was decreased in the transgenic plants. A total of 1082 and 1072 proteins were profiled by proteomics under control and salt treatment, respectively, with 22 and 11 proteins uniquely identified under control and salt stress, respectively. Among the 11 proteins, 7 were increased and 4 were decreased after salt treatment. Most of the proteins whose expression increased in the McHB7 overexpression (OE) ice plants under high salinity were involved in transport regulation, catalytic activities, biosynthesis of secondary metabolites, and response to stimulus. The results demonstrate that the McHB7 transcription factor plays a positive role in improving plant salt tolerance.


Assuntos
Mesembryanthemum/metabolismo , Proteínas de Plantas/metabolismo , Proteômica , Tolerância ao Sal/fisiologia , Sequência de Aminoácidos , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Biologia Computacional , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ontologia Genética , Mesembryanthemum/efeitos dos fármacos , Mesembryanthemum/genética , Filogenia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Transporte Proteico/efeitos dos fármacos , Salinidade , Tolerância ao Sal/efeitos dos fármacos , Tolerância ao Sal/genética , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Frações Subcelulares/metabolismo , Fatores de Transcrição/metabolismo
12.
Ecotoxicol Environ Saf ; 221: 112469, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34198190

RESUMO

Glutathione S-transferase (GST) is the key enzyme in glutathione (GSH) synthesis, and plays a crucial role in copper (Cu) detoxification. Nonetheless, its regulatory mechanisms remain largely unclear. In this study, we identified a Cu-induced glutathione S-transferase 1 (TaGST1) gene in wheat. Yeast one-hybrid (Y1H) screened out TaWRKY74, which was one member from the WRKY transcription factor family. The bindings between TaGST1 promoter and TaWRKY74 were further verified by using another Y1H and luciferase assays. Expression of TaWRKY74 was induced more than 30-folds by Cu stress. Functions of TaWRKY74 were tested by using transiently silence methods. In transiently TaWRKY74-silenced wheat plants, TaWRKY74 and TaGST1 expression, GST activity, and GSH content was significantly inhibited by 25.68%, 19.88%, 27.66%, and 12.68% in shoots, and 53.81%, 52.11%, 23.47%, and 17.11% in roots, respectively. However, contents of hydrogen peroxide, malondialdehyde, or Cu were significantly increased by 2.58%, 12.45%, or 37.74% in shoots, and 25.24%, 53.84%, and 103.99% in roots, respectively. Notably, exogenous application of GSH reversed the adverse effects of transiently TaWRKY74-silenced wheat plants during Cu stress. Taken together, our results suggesting that TaWRKY74 regulated TaGST1 expression and affected GSH accumulation under Cu stress, and could be useful to ameliorate Cu toxicity for crop food safety.


Assuntos
Cobre/toxicidade , Glutationa Transferase/metabolismo , Glutationa/metabolismo , Proteínas de Plantas/metabolismo , Fatores de Transcrição/metabolismo , Triticum/efeitos dos fármacos , Fatores de Transcrição/genética , Triticum/genética , Triticum/metabolismo , Técnicas do Sistema de Duplo-Híbrido , Leveduras/genética
13.
Nat Commun ; 12(1): 4176, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34234134

RESUMO

Mammalian reovirus (MRV) is the prototypical member of genus Orthoreovirus of family Reoviridae. However, lacking high-resolution structures of its RNA polymerase cofactor µ2 and infectious particle, limits understanding of molecular interactions among proteins and RNA, and their contributions to virion assembly and RNA transcription. Here, we report the 3.3 Å-resolution asymmetric reconstruction of transcribing MRV and in situ atomic models of its capsid proteins, the asymmetrically attached RNA-dependent RNA polymerase (RdRp) λ3, and RdRp-bound nucleoside triphosphatase µ2 with a unique RNA-binding domain. We reveal molecular interactions among virion proteins and genomic and messenger RNA. Polymerase complexes in three Spinoreovirinae subfamily members are organized with different pseudo-D3d symmetries to engage their highly diversified genomes. The above interactions and those between symmetry-mismatched receptor-binding σ1 trimers and RNA-capping λ2 pentamers balance competing needs of capsid assembly, external protein removal, and allosteric triggering of endogenous RNA transcription, before, during and after infection, respectively.


Assuntos
Proteínas do Capsídeo/metabolismo , Nucleosídeo-Trifosfatase/metabolismo , Orthoreovirus/ultraestrutura , RNA Viral/metabolismo , Fatores de Transcrição/metabolismo , Regulação Alostérica , Animais , Proteínas do Capsídeo/ultraestrutura , Linhagem Celular , Microscopia Crioeletrônica , Regulação Viral da Expressão Gênica , Genoma Viral , Macaca mulatta , Nucleosídeo-Trifosfatase/ultraestrutura , Orthoreovirus/genética , Orthoreovirus/metabolismo , Multimerização Proteica , RNA de Cadeia Dupla/metabolismo , RNA de Cadeia Dupla/ultraestrutura , RNA Mensageiro/metabolismo , RNA Viral/ultraestrutura , RNA Polimerase Dependente de RNA/metabolismo , Fatores de Transcrição/ultraestrutura , Ativação Transcricional , Montagem de Vírus/genética
14.
Nat Commun ; 12(1): 4130, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-34226546

RESUMO

Chromosomal translocations of the AF10 (or MLLT10) gene are frequently found in acute leukemias. Here, we show that the PZP domain of AF10 (AF10PZP), which is consistently impaired or deleted in leukemogenic AF10 translocations, plays a critical role in blocking malignant transformation. Incorporation of functional AF10PZP into the leukemogenic CALM-AF10 fusion prevents the transforming activity of the fusion in bone marrow-derived hematopoietic stem and progenitor cells in vitro and in vivo and abrogates CALM-AF10-mediated leukemogenesis in vivo. Crystallographic, biochemical and mutagenesis studies reveal that AF10PZP binds to the nucleosome core particle through multivalent contacts with the histone H3 tail and DNA and associates with chromatin in cells, colocalizing with active methylation marks and discriminating against the repressive H3K27me3 mark. AF10PZP promotes nuclear localization of CALM-AF10 and is required for association with chromatin. Our data indicate that the disruption of AF10PZP function in the CALM-AF10 fusion directly leads to transformation, whereas the inclusion of AF10PZP downregulates Hoxa genes and reverses cellular transformation. Our findings highlight the molecular mechanism by which AF10 targets chromatin and suggest a model for the AF10PZP-dependent CALM-AF10-mediated leukemogenesis.


Assuntos
Doença Aguda , Leucemia Mieloide Aguda/genética , Fatores de Transcrição/química , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Translocação Genética/genética , Animais , Carcinogênese/genética , Transformação Celular Neoplásica/genética , Cromatina , Células HEK293 , Histonas/metabolismo , Humanos , Leucemia Mieloide Aguda/metabolismo , Metilação , Camundongos , Modelos Moleculares , Proteínas Monoméricas de Montagem de Clatrina/genética , Proteínas Monoméricas de Montagem de Clatrina/metabolismo , Nucleossomos , Conformação Proteica
15.
Nat Commun ; 12(1): 4155, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34230480

RESUMO

The organization of an integrated coronary vasculature requires the specification of immature endothelial cells (ECs) into arterial and venous fates based on their localization within the heart. It remains unclear how spatial information controls EC identity and behavior. Here we use single-cell RNA sequencing at key developmental timepoints to interrogate cellular contributions to coronary vessel patterning and maturation. We perform transcriptional profiling to define a heterogenous population of epicardium-derived cells (EPDCs) that express unique chemokine signatures. We identify a population of Slit2+ EPDCs that emerge following epithelial-to-mesenchymal transition (EMT), which we term vascular guidepost cells. We show that the expression of guidepost-derived chemokines such as Slit2 are induced in epicardial cells undergoing EMT, while mesothelium-derived chemokines are silenced. We demonstrate that epicardium-specific deletion of myocardin-related transcription factors in mouse embryos disrupts the expression of key guidance cues and alters EPDC-EC signaling, leading to the persistence of an immature angiogenic EC identity and inappropriate accumulation of ECs on the epicardial surface. Our study suggests that EC pathfinding and fate specification is controlled by a common mechanism and guided by paracrine signaling from EPDCs linking epicardial EMT to EC localization and fate specification in the developing heart.


Assuntos
Células Endoteliais/citologia , Células Endoteliais/metabolismo , Pericárdio/citologia , Pericárdio/metabolismo , Animais , Quimiocinas , Vasos Coronários/metabolismo , Embrião de Mamíferos , Transição Epitelial-Mesenquimal , Expressão Gênica , Coração , Peptídeos e Proteínas de Sinalização Intercelular , Camundongos , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso , Proteínas Nucleares , Pericárdio/embriologia , Fator de Resposta Sérica , Transdução de Sinais , Transativadores , Fatores de Transcrição/metabolismo , Transcriptoma
16.
Nat Commun ; 12(1): 4148, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34230481

RESUMO

Osteoarthritis (OA), the most common aging-related joint disease, is caused by an imbalance between extracellular matrix synthesis and degradation. Here, we discover that both strands of microRNA-455 (miR-455), -5p and -3p, are up-regulated by Sox9, an essential transcription factor for cartilage differentiation and function. Both miR-455-5p and -3p are highly expressed in human chondrocytes from normal articular cartilage and in mouse primary chondrocytes. We generate miR-455 knockout mice, and find that cartilage degeneration mimicking OA and elevated expression of cartilage degeneration-related genes are observed at 6-months-old. Using a cell-based miRNA target screening system, we identify hypoxia-inducible factor-2α (HIF-2α), a catabolic factor for cartilage homeostasis, as a direct target of both miR-455-5p and -3p. In addition, overexpression of both miR-455-5p and -3p protect cartilage degeneration in a mouse OA model, demonstrating their potential therapeutic value. Furthermore, knockdown of HIF-2α in 6-month-old miR-455 knockout cartilage rescues the elevated expression of cartilage degeneration-related genes. These data demonstrate that both strands of a miRNA target the same gene to regulate articular cartilage homeostasis.


Assuntos
Cartilagem/metabolismo , Homeostase , Hipóxia/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Fatores de Transcrição/metabolismo , Animais , Cartilagem Articular/metabolismo , Condrócitos/metabolismo , Matriz Extracelular/metabolismo , Regulação da Expressão Gênica , Humanos , Camundongos , Camundongos Knockout , Osteoartrite/genética , Fatores de Transcrição SOX9
17.
Int J Mol Sci ; 22(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206382

RESUMO

Emerin is the inner nuclear membrane protein involved in maintaining the mechanical integrity of the nuclear membrane. Mutations in EMD encoding emerin cause Emery-Dreifuss muscular dystrophy (EDMD). Evidence is accumulating that emerin regulation of specific gene expression is associated with this disease, but the exact function of emerin has not been fully elucidated. Here, we show that emerin downregulates Signal transducer and activators of transcription 3 (STAT3) signaling, activated exclusively by Janus kinase (JAK). Deletion mutation experiments show that the lamin-binding domain of emerin is essential for the inhibition of STAT3 signaling. Emerin interacts directly and co-localizes with STAT3 in the nuclear membrane. Emerin knockdown induces STAT3 target genes Bcl2 and Survivin to increase cell survival signals and suppress hydrogen peroxide-induced cell death in HeLa cells. Specifically, downregulation of BAF or lamin A/C increases STAT3 signaling, suggesting that correct-localized emerin, by assembling with BAF and lamin A/C, acts as an intrinsic inhibitor against STAT3 signaling. In C2C12 cells, emerin knockdown induces STAT3 target gene, Pax7, and activated abnormal myoblast proliferation associated with muscle wasting in skeletal muscle homeostasis. Our results indicate that emerin downregulates STAT3 signaling by inducing retention of STAT3 and delaying STAT3 signaling in the nuclear membrane. This mechanism provides clues to the etiology of emerin-related muscular dystrophy and may be a new therapeutic target for treatment.


Assuntos
Proteínas de Membrana/metabolismo , Membrana Nuclear/metabolismo , Proteínas Nucleares/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Células A549 , Núcleo Celular/metabolismo , Sobrevivência Celular , Regulação da Expressão Gênica , Humanos , Janus Quinases/metabolismo , Músculo Esquelético/metabolismo , Distrofias Musculares/etiologia , Distrofias Musculares/metabolismo , Distrofias Musculares/patologia , Mutação , Ligação Proteica , Fator de Transcrição STAT3/genética , Fatores de Transcrição/metabolismo
18.
Int J Mol Sci ; 22(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206594

RESUMO

Classical models of gene expression were built using genetics and biochemistry. Although these approaches are powerful, they have very limited consideration of the spatial and temporal organization of gene expression. Although the spatial organization and dynamics of RNA polymerase II (RNAPII) transcription machinery have fundamental functional consequences for gene expression, its detailed studies have been abrogated by the limits of classical light microscopy for a long time. The advent of super-resolution microscopy (SRM) techniques allowed for the visualization of the RNAPII transcription machinery with nanometer resolution and millisecond precision. In this review, we summarize the recent methodological advances in SRM, focus on its application for studies of the nanoscale organization in space and time of RNAPII transcription, and discuss its consequences for the mechanistic understanding of gene expression.


Assuntos
Regulação da Expressão Gênica , Microscopia de Fluorescência , RNA Polimerase II/metabolismo , Imagem Individual de Molécula/métodos , Transcrição Genética , Animais , Humanos , Microscopia de Fluorescência/métodos , Ligação Proteica , Fatores de Transcrição/metabolismo
19.
Int J Mol Sci ; 22(13)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206257

RESUMO

Toll-like receptors (TLRs) are a family of pattern recognition receptors (PRRs) that modulate innate immune responses and play essential roles in the pathogenesis of heart diseases. Although important, the molecular mechanisms controlling cardiac TLR genes expression have not been clearly addressed. This study examined the expression pattern of Tlr1, Tlr2, Tlr3, Tlr4, Tlr5, Tlr6, Tlr7, Tlr8, and Tlr9 in normal and disease-stressed mouse hearts. Our results demonstrated that the expression levels of cardiac Tlr3, Tlr7, Tlr8, and Tlr9 increased with age between neonatal and adult developmental stages, whereas the expression of Tlr5 decreased with age. Furthermore, pathological stress increased the expression levels of Tlr2, Tlr4, Tlr5, Tlr7, Tlr8, and Tlr9. Hippo-YAP signaling is essential for heart development and homeostasis maintenance, and YAP/TEAD1 complex is the terminal effector of this pathway. Here we found that TEAD1 directly bound genomic regions adjacent to Tlr1, Tlr2, Tlr3, Tlr4, Tlr5, Tlr6, Tlr7, and Tlr9. In vitro, luciferase reporter data suggest that YAP/TEAD1 repression of Tlr4 depends on a conserved TEAD1 binding motif near Tlr4 transcription start site. In vivo, cardiomyocyte-specific YAP depletion increased the expression of most examined TLR genes, activated the synthesis of pro-inflammatory cytokines, and predisposed the heart to lipopolysaccharide stress. In conclusion, our data indicate that the expression of cardiac TLR genes is associated with age and activated by pathological stress and suggest that YAP/TEAD1 complex is a default repressor of cardiac TLR genes.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Ligação a DNA/metabolismo , Imunidade Inata , Miócitos Cardíacos/metabolismo , Receptores Toll-Like/genética , Fatores de Transcrição/metabolismo , Fatores Etários , Animais , Citocinas/metabolismo , Regulação da Expressão Gênica , Lipopolissacarídeos , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais
20.
Int J Mol Sci ; 22(12)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207084

RESUMO

Advanced glycation end products (AGEs) are formed via nonenzymatic reactions between reducing sugars and proteins. Recent studies have shown that methylglyoxal, a potent precursor for AGEs, causes a variety of biological dysfunctions, including diabetes, inflammation, renal failure, and cancer. However, little is known about the function of methylglyoxal-derived AGEs (AGE4) in kidney cells. Therefore, we verified the expression of endoplasmic reticulum (ER) stress-related genes and apoptosis markers to determine the effects of AGE4 on human proximal epithelial cells (HK-2). Moreover, our results showed that AGE4 induced the expression of apoptosis markers, such as Bax, p53, and kidney injury molecule-1, but downregulated Bcl-2 and cyclin D1 levels. AGE4 also promoted the expression of NF-κB, serving as a transcription factor, and the phosphorylation of c-Jun NH2-terminal kinase (JNK), which induced cell apoptosis and ER stress mediated by the JNK inhibitor. Furthermore, AGE4 induced mitochondrial dysfunction by inducing the permeabilization of the mitochondrial membrane and ATP synthesis. Through in vitro and in vivo experiments, this study provides a new perspective on renal dysfunction with regard to the AGE4-induced RAGE /JNK signaling pathway, which leads to renal cell apoptosis via the imbalance of mitochondrial function and ER stress in kidney damage.


Assuntos
Apoptose , Estresse do Retículo Endoplasmático , Produtos Finais de Glicação Avançada/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Mitocôndrias/metabolismo , Aldeído Pirúvico/metabolismo , Transdução de Sinais , Animais , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Células Epiteliais/metabolismo , Produtos Finais de Glicação Avançada/farmacologia , Humanos , Rim/metabolismo , Camundongos , Mitocôndrias/efeitos dos fármacos , Modelos Biológicos , NF-kappa B/metabolismo , Espécies Reativas de Oxigênio , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/metabolismo
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