Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 74
Filtrar
1.
Cell ; 167(1): 219-232.e14, 2016 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-27662090

RESUMO

Gene silencing is instrumental to interrogate gene function and holds promise for therapeutic applications. Here, we repurpose the endogenous retroviruses' silencing machinery of embryonic stem cells to stably silence three highly expressed genes in somatic cells by epigenetics. This was achieved by transiently expressing combinations of engineered transcriptional repressors that bind to and synergize at the target locus to instruct repressive histone marks and de novo DNA methylation, thus ensuring long-term memory of the repressive epigenetic state. Silencing was highly specific, as shown by genome-wide analyses, sharply confined to the targeted locus without spreading to nearby genes, resistant to activation induced by cytokine stimulation, and relieved only by targeted DNA demethylation. We demonstrate the portability of this technology by multiplex gene silencing, adopting different DNA binding platforms and interrogating thousands of genomic loci in different cell types, including primary T lymphocytes. Targeted epigenome editing might have broad application in research and medicine.


Assuntos
DNA (Citosina-5-)-Metiltransferases/metabolismo , Edição de Genes/métodos , Inativação Gênica , Marcação de Genes/métodos , Fatores de Transcrição Kruppel-Like/metabolismo , Proteínas Repressoras/metabolismo , Domínio Catalítico , DNA (Citosina-5-)-Metiltransferases/genética , Metilação de DNA , DNA Metiltransferase 3A , Células-Tronco Embrionárias/metabolismo , Engenharia Genética , Humanos , Fatores de Transcrição Kruppel-Like/genética , Proteínas Repressoras/genética , Linfócitos T/metabolismo
2.
EMBO J ; 42(10): e112234, 2023 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-36970857

RESUMO

The interferon-induced transmembrane proteins (IFITM) are implicated in several biological processes, including antiviral defense, but their modes of action remain debated. Here, taking advantage of pseudotyped viral entry assays and replicating viruses, we uncover the requirement of host co-factors for endosomal antiviral inhibition through high-throughput proteomics and lipidomics in cellular models of IFITM restriction. Unlike plasma membrane (PM)-localized IFITM restriction that targets infectious SARS-CoV2 and other PM-fusing viral envelopes, inhibition of endosomal viral entry depends on lysines within the conserved IFITM intracellular loop. These residues recruit Phosphatidylinositol 3,4,5-trisphosphate (PIP3) that we show here to be required for endosomal IFITM activity. We identify PIP3 as an interferon-inducible phospholipid that acts as a rheostat for endosomal antiviral immunity. PIP3 levels correlated with the potency of endosomal IFITM restriction and exogenous PIP3 enhanced inhibition of endocytic viruses, including the recent SARS-CoV2 Omicron variant. Together, our results identify PIP3 as a critical regulator of endosomal IFITM restriction linking it to the Pi3K/Akt/mTORC pathway and elucidate cell-compartment-specific antiviral mechanisms with potential relevance for the development of broadly acting antiviral strategies.


Assuntos
Antivirais , COVID-19 , Humanos , Interferons/metabolismo , Fosfolipídeos , Fosfatidilinositol 3-Quinases/metabolismo , RNA Viral , Proteínas de Ligação a RNA/metabolismo , SARS-CoV-2/metabolismo , Internalização do Vírus , Proteínas de Membrana/metabolismo
3.
EMBO J ; 41(22): e108040, 2022 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-36215697

RESUMO

The ribonuclease DIS3 is one of the most frequently mutated genes in the hematological cancer multiple myeloma, yet the basis of its tumor suppressor function in this disease remains unclear. Herein, exploiting the TCGA dataset, we found that DIS3 plays a prominent role in the DNA damage response. DIS3 inactivation causes genomic instability by increasing mutational load, and a pervasive accumulation of DNA:RNA hybrids that induces genomic DNA double-strand breaks (DSBs). DNA:RNA hybrid accumulation also prevents binding of the homologous recombination (HR) machinery to double-strand breaks, hampering DSB repair. DIS3-inactivated cells become sensitive to PARP inhibitors, suggestive of a defect in homologous recombination repair. Accordingly, multiple myeloma patient cells mutated for DIS3 harbor an increased mutational burden and a pervasive overexpression of pro-inflammatory interferon, correlating with the accumulation of DNA:RNA hybrids. We propose DIS3 loss in myeloma to be a driving force for tumorigenesis via DNA:RNA hybrid-dependent enhanced genome instability and increased mutational rate. At the same time, DIS3 loss represents a liability that might be therapeutically exploited in patients whose cancer cells harbor DIS3 mutations.


Assuntos
Mieloma Múltiplo , Humanos , Mieloma Múltiplo/genética , Mieloma Múltiplo/patologia , Ribonucleases/metabolismo , Reparo de DNA por Recombinação , Recombinação Homóloga , Instabilidade Genômica , Reparo do DNA , DNA/metabolismo , RNA , Complexo Multienzimático de Ribonucleases do Exossomo/metabolismo
4.
Bioinformatics ; 40(5)2024 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-38696763

RESUMO

MOTIVATION: Single-cell profiling has become a common practice to investigate the complexity of tissues, organs, and organisms. Recent technological advances are expanding our capabilities to profile various molecular layers beyond the transcriptome such as, but not limited to, the genome, the epigenome, and the proteome. Depending on the experimental procedure, these data can be obtained from separate assays or the very same cells. Yet, integration of more than two assays is currently not supported by the majority of the computational frameworks avaiable. RESULTS: We here propose a Multi-Omic data integration framework based on Wasserstein Generative Adversarial Networks suitable for the analysis of paired or unpaired data with a high number of modalities (>2). At the core of our strategy is a single network trained on all modalities together, limiting the computational burden when many molecular layers are evaluated. AVAILABILITY AND IMPLEMENTATION: Source code of our framework is available at https://github.com/vgiansanti/MOWGAN.


Assuntos
Análise de Célula Única , Análise de Célula Única/métodos , Humanos , Biologia Computacional/métodos , Proteoma/metabolismo , Software , Transcriptoma
5.
EMBO J ; 37(23)2018 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-30373810

RESUMO

Focal deletions occur frequently in the cancer genome. However, the putative tumor-suppressive genes residing within these regions have been difficult to pinpoint. To robustly identify these genes, we implemented a computational approach based on non-negative matrix factorization, NMF, and interrogated the TCGA dataset. This analysis revealed a metagene signature including a small subset of genes showing pervasive hemizygous deletions, reduced expression in cancer patient samples, and nucleolar function. Amid the genes belonging to this signature, we have identified PNRC1, a nuclear receptor coactivator. We found that PNRC1 interacts with the cytoplasmic DCP1α/DCP2 decapping machinery and hauls it inside the nucleolus. PNRC1-dependent nucleolar translocation of the decapping complex is associated with a decrease in the 5'-capped U3 and U8 snoRNA fractions, hampering ribosomal RNA maturation. As a result, PNRC1 ablates the enhanced proliferation triggered by established oncogenes such as RAS and MYC These observations uncover a previously undescribed mechanism of tumor suppression, whereby the cytoplasmic decapping machinery is hauled within nucleoli, tightly regulating ribosomal RNA maturation.


Assuntos
Nucléolo Celular/metabolismo , Proliferação de Células , Neoplasias/metabolismo , Proteínas Nucleares/metabolismo , RNA Ribossômico/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Células A549 , Nucléolo Celular/genética , Nucléolo Celular/patologia , Bases de Dados de Ácidos Nucleicos , Endorribonucleases/genética , Endorribonucleases/metabolismo , Células HeLa , Humanos , Células MCF-7 , Neoplasias/genética , Neoplasias/patologia , Proteínas Nucleares/genética , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , RNA Ribossômico/genética , RNA Nucleolar Pequeno/genética , RNA Nucleolar Pequeno/metabolismo , Transativadores/genética , Transativadores/metabolismo , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética , Proteínas ras/genética , Proteínas ras/metabolismo
6.
BMC Bioinformatics ; 22(1): 576, 2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34847879

RESUMO

Single cell profiling has been proven to be a powerful tool in molecular biology to understand the complex behaviours of heterogeneous system. The definition of the properties of single cells is the primary endpoint of such analysis, cells are typically clustered to underpin the common determinants that can be used to describe functional properties of the cell mixture under investigation. Several approaches have been proposed to identify cell clusters; while this is matter of active research, one popular approach is based on community detection in neighbourhood graphs by optimisation of modularity. In this paper we propose an alternative and principled solution to this problem, based on Stochastic Block Models. We show that such approach not only is suitable for identification of cell groups, it also provides a solid framework to perform other relevant tasks in single cell analysis, such as label transfer. To encourage the use of Stochastic Block Models, we developed a python library, schist, that is compatible with the popular scanpy framework.


Assuntos
Análise de Célula Única
7.
Medicina (Kaunas) ; 57(9)2021 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-34577784

RESUMO

BACKGROUND AND OBJECTIVES: Cocaine users may present with positive antineutrophil cytoplasmic antibodies (ANCA) and severe midline destructive lesions (CIMDL) which are histologically characterized by massive apoptosis. However, histopathological and laboratory studies suggest that autoimmunity may not be the main pathogenic driver. We analyzed gene expression both in cell lines of nasal mucosa exposed to cocaine and in CIMDL patients to determine whether genetic predisposition might cause such lesions, which are observed in a minority of cocaine abusers. MATERIALS AND METHODS: The genetic expression profile of nasal mucosa exposed to cocaine was analyzed. Rare variants of expressed genes were searched in patients with CIMDL using exome sequencing and bio-informatics. RESULTS: We identified 462 genes that were induced by cocaine, mainly related to apoptosis and autophagy in response to oxidative stress. Under the hypothesis that genes linked to the phenotype are also induced by cocaine itself, a rare variants burden test was performed to select genes that were significantly enriched in rare mutations. Next, 11 cocaine abusers with CIMDL and no other relevant medical comorbidities underwent exome sequencing, and 12 genes that were significantly enriched in the burden test and present in at least 10 patients were identified. An in-depth analysis of these genes revealed their involvement in apoptosis, tissue homeostasis, autophagy, and response to oxidative stress. CONCLUSIONS: Oxidative stress and rare genetic alterations in the response to reactive oxygen species, apoptosis, autophagy, and tissue regeneration are plausible drivers of damage affecting nasal mucosa exposed to cocaine crystals and, consequently, the pathogenic mechanism behind CIMDL.


Assuntos
Transtornos Relacionados ao Uso de Cocaína , Cocaína , Anticorpos Anticitoplasma de Neutrófilos , Cocaína/efeitos adversos , Transtornos Relacionados ao Uso de Cocaína/genética , Expressão Gênica , Humanos
8.
Hum Genet ; 139(11): 1471-1483, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32583022

RESUMO

Human growth is a complex trait determined by genetic factors in combination with external stimuli, including environment, nutrition and hormonal status. In the past, several genome-wide association studies (GWAS) have collectively identified hundreds of genetic variants having a putative effect on determining adult height in different worldwide populations. Theoretically, a valuable approach to better understand the mechanisms of complex traits as adult height is to study a population exhibiting extreme stature phenotypes, such as African Baka Pygmies. After phenotypic characterization, we sequenced the whole exomes of a cohort of Baka Pygmies and their non-Pygmies Bantu neighbors to highlight genetic variants associated with the reduced stature. Whole exome data analysis revealed 29 single nucleotide polymorphisms (SNPs) significantly associated with the reduced height in the Baka group. Among these variants, we focused on SNP rs7629425, located in the 5'-UTR of the Hyaluronidase-2 (HYAL2) gene. The frequency of the alternative allele was significantly increased compared to African and non-African populations. In vitro luciferase assay showed significant differences in transcription modulation by rs7629425 C/T alleles. In conclusion, our results suggested that the HYAL2 gene variants may play a role in the etiology of short stature in Baka Pygmies population.


Assuntos
População Negra/genética , Moléculas de Adesão Celular/genética , Proteínas Ligadas por GPI/genética , Transtornos do Crescimento/genética , Hialuronoglucosaminidase/genética , Polimorfismo de Nucleotídeo Único/genética , Adulto , Alelos , Estatura/genética , Exoma/genética , Feminino , Estudo de Associação Genômica Ampla/métodos , Humanos , Masculino
9.
Brain ; 142(8): 2319-2335, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31257402

RESUMO

Genetic mutations in TBC1D24 have been associated with multiple phenotypes, with epilepsy being the main clinical manifestation. The TBC1D24 protein consists of the unique association of a Tre2/Bub2/Cdc16 (TBC) domain and a TBC/lysin motif domain/catalytic (TLDc) domain. More than 50 missense and loss-of-function mutations have been described and are spread over the entire protein. Through whole genome/exome sequencing we identified compound heterozygous mutations, R360H and G501R, within the TLDc domain, in an index family with a Rolandic epilepsy exercise-induced dystonia phenotype (http://omim.org/entry/608105). A 20-year long clinical follow-up revealed that epilepsy was self-limited in all three affected patients, but exercise-induced dystonia persisted into adulthood in two. Furthermore, we identified three additional sporadic paediatric patients with a remarkably similar phenotype, two of whom had compound heterozygous mutations consisting of an in-frame deletion I81_K84 and an A500V mutation, and the third carried T182M and G511R missense mutations, overall revealing that all six patients harbour a missense mutation in the subdomain of TLDc between residues 500 and 511. We solved the crystal structure of the conserved Drosophila TLDc domain. This allowed us to predict destabilizing effects of the G501R and G511R mutations and, to a lesser degree, of R360H and potentially A500V. Next, we characterized the functional consequences of a strong and a weak TLDc mutation (TBC1D24G501R and TBC1D24R360H) using Drosophila, where TBC1D24/Skywalker regulates synaptic vesicle trafficking. In a Drosophila model neuronally expressing human TBC1D24, we demonstrated that the TBC1D24G501R TLDc mutation causes activity-induced locomotion and synaptic vesicle trafficking defects, while TBC1D24R360H is benign. The neuronal phenotypes of the TBC1D24G501R mutation are consistent with exacerbated oxidative stress sensitivity, which is rescued by treating TBC1D24G501R mutant animals with antioxidants N-acetylcysteine amide or α-tocopherol as indicated by restored synaptic vesicle trafficking levels and sustained behavioural activity. Our data thus show that mutations in the TLDc domain of TBC1D24 cause Rolandic-type focal motor epilepsy and exercise-induced dystonia. The humanized TBC1D24G501R fly model exhibits sustained activity and vesicle transport defects. We propose that the TBC1D24/Sky TLDc domain is a reactive oxygen species sensor mediating synaptic vesicle trafficking rates that, when dysfunctional, causes a movement disorder in patients and flies. The TLDc and TBC domain mutations' response to antioxidant treatment we observed in the animal model suggests a potential for combining antioxidant-based therapeutic approaches to TBC1D24-associated disorders with previously described lipid-altering strategies for TBC domain mutations.


Assuntos
Acetilcisteína/análogos & derivados , Antioxidantes/uso terapêutico , Modelos Animais de Doenças , Drosophila melanogaster/fisiologia , Distonia/tratamento farmacológico , Epilepsia Rolândica/genética , Proteínas Ativadoras de GTPase/genética , Esforço Físico , alfa-Tocoferol/uso terapêutico , Acetilcisteína/uso terapêutico , Adolescente , Motivos de Aminoácidos/genética , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Transporte Biológico/efeitos dos fármacos , Domínio Catalítico/genética , Criança , Pré-Escolar , Cristalografia por Raios X , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Distonia/etiologia , Epilepsia Rolândica/tratamento farmacológico , Feminino , Proteínas Ativadoras de GTPase/química , Proteínas Ativadoras de GTPase/fisiologia , Humanos , Lactente , Locomoção/genética , Locomoção/fisiologia , Masculino , Modelos Moleculares , Mutação de Sentido Incorreto , Neurônios/fisiologia , Estresse Oxidativo , Linhagem , Conformação Proteica , Espécies Reativas de Oxigênio/metabolismo , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência , Deleção de Sequência , Homologia de Sequência de Aminoácidos , Vesículas Sinápticas/metabolismo , Proteínas rab de Ligação ao GTP/química , Proteínas rab de Ligação ao GTP/genética
10.
Proc Natl Acad Sci U S A ; 113(51): E8286-E8295, 2016 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-27930306

RESUMO

Invariant natural killer T cells (iNKT) cells are T lymphocytes displaying innate effector functions, acquired through a distinct thymic developmental program regulated by microRNAs (miRNAs). Deleting miRNAs by Dicer ablation (Dicer KO) in thymocytes selectively impairs iNKT cell survival and functional differentiation. To unravel this miRNA-dependent program, we systemically identified transcripts that were differentially expressed between WT and Dicer KO iNKT cells at different differentiation stages and predicted to be targeted by the iNKT cell-specific miRNAs. TGF-ß receptor II (TGF-ßRII), critically implicated in iNKT cell differentiation, was found up-regulated in iNKT Dicer KO cells together with enhanced TGF-ß signaling. miRNA members of the miR-17∼92 family clusters were predicted to target Tgfbr2 mRNA upon iNKT cell development. iNKT cells lacking all three miR-17∼92 family clusters (miR-17∼92, miR-106a∼363, miR-106b∼25) phenocopied both increased TGF-ßRII expression and signaling, and defective effector differentiation, displayed by iNKT Dicer KO cells. Consistently, genetic ablation of TGF-ß signaling in the absence of miRNAs rescued iNKT cell differentiation. These results elucidate the global impact of miRNAs on the iNKT cell developmental program and uncover the targeting of a lineage-specific cytokine signaling by miRNAs as a mechanism regulating innate-like T-cell development and effector differentiation.


Assuntos
MicroRNAs/genética , Células T Matadoras Naturais/citologia , Fator de Crescimento Transformador beta/metabolismo , Animais , Antígenos CD1d/metabolismo , Diferenciação Celular , Citocinas/metabolismo , RNA Helicases DEAD-box/genética , Perfilação da Expressão Gênica , Teste de Complementação Genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Família Multigênica , Fenótipo , RNA Mensageiro/metabolismo , Ribonuclease III/genética , Transdução de Sinais , Timo/metabolismo
11.
Clin Immunol ; 178: 20-28, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-26732860

RESUMO

Activated PI3-kinase delta syndrome (APDS) was recently reported as a novel primary immunodeficiency caused by heterozygous gain-of-function mutations in PIK3CD gene. Here we describe immunological studies in a 19year old APDS patient for whom genetic diagnosis was discovered by Whole Exome Sequencing (WES) analysis. In addition to the progressive lymphopenia and defective antibody production we showed that the ability of the patient's B cells to differentiate in vitro is severely reduced. An in depth analysis of the myeloid compartment showed an increased expression of CD83 activation marker on monocytes and mono-derived DC cells. Moreover, monocytes-derived macrophages (MDMs) failed to solve the Mycobacterium bovis bacillus Calmette Guèrin (BCG) infection in vitro. Selective p110δ inhibitor IC87114 restored the MDM capacity to kill BCG in vitro. Our data show that the constitutive activation of Akt-mTOR pathway induces important alterations also in the myeloid compartment providing new insights in order to improve the therapeutic approach in these patients.


Assuntos
Linfócitos B/imunologia , Diferenciação Celular/imunologia , Células Dendríticas/imunologia , Síndromes de Imunodeficiência/imunologia , Macrófagos/imunologia , Adenina/análogos & derivados , Adenina/farmacologia , Diferenciação Celular/genética , Classe I de Fosfatidilinositol 3-Quinases/genética , Classe I de Fosfatidilinositol 3-Quinases/imunologia , Humanos , Síndromes de Imunodeficiência/genética , Técnicas In Vitro , Inflamação , Linfopenia/genética , Linfopenia/imunologia , Macrófagos/efeitos dos fármacos , Masculino , Mycobacterium bovis/imunologia , Doenças da Imunodeficiência Primária , Proteínas Proto-Oncogênicas c-akt/imunologia , Quinazolinas/farmacologia , Transdução de Sinais , Serina-Treonina Quinases TOR/imunologia , Adulto Jovem
12.
Nucleic Acids Res ; 43(5): 2560-74, 2015 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-25712104

RESUMO

DNA replication is a tightly regulated process that initiates from multiple replication origins and leads to the faithful transmission of the genetic material. For proper DNA replication, the chromatin surrounding origins needs to be remodeled. However, remarkably little is known on which epigenetic changes are required to allow the firing of replication origins. Here, we show that the histone demethylase KDM5C/JARID1C is required for proper DNA replication at early origins. JARID1C dictates the assembly of the pre-initiation complex, driving the binding to chromatin of the pre-initiation proteins CDC45 and PCNA, through the demethylation of the histone mark H3K4me3. Fork activation and histone H4 acetylation, additional early events involved in DNA replication, are not affected by JARID1C downregulation. All together, these data point to a prominent role for JARID1C in a specific phase of DNA replication in mammalian cells, through its demethylase activity on H3K4me3.


Assuntos
Replicação do DNA , Histonas/metabolismo , Oxirredutases N-Desmetilantes/metabolismo , Origem de Replicação , Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Cromatina/genética , Cromatina/metabolismo , Células HeLa , Histona Desmetilases , Humanos , Immunoblotting , Lisina/metabolismo , Metilação , Oxirredutases N-Desmetilantes/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Ligação Proteica , Interferência de RNA , Fatores de Tempo
13.
Nucleic Acids Res ; 43(W1): W589-98, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25897122

RESUMO

The BioMart Community Portal (www.biomart.org) is a community-driven effort to provide a unified interface to biomedical databases that are distributed worldwide. The portal provides access to numerous database projects supported by 30 scientific organizations. It includes over 800 different biological datasets spanning genomics, proteomics, model organisms, cancer data, ontology information and more. All resources available through the portal are independently administered and funded by their host organizations. The BioMart data federation technology provides a unified interface to all the available data. The latest version of the portal comes with many new databases that have been created by our ever-growing community. It also comes with better support and extensibility for data analysis and visualization tools. A new addition to our toolbox, the enrichment analysis tool is now accessible through graphical and web service interface. The BioMart community portal averages over one million requests per day. Building on this level of service and the wealth of information that has become available, the BioMart Community Portal has introduced a new, more scalable and cheaper alternative to the large data stores maintained by specialized organizations.


Assuntos
Sistemas de Gerenciamento de Base de Dados , Genômica , Humanos , Internet , Neoplasias/genética , Proteômica
14.
Genome Res ; 23(1): 1-11, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23187890

RESUMO

We report the genome-wide mapping of ORC1 binding sites in mammals, by chromatin immunoprecipitation and parallel sequencing (ChIP-seq). ORC1 binding sites in HeLa cells were validated as active DNA replication origins (ORIs) using Repli-seq, a method that allows identification of ORI-containing regions by parallel sequencing of temporally ordered replicating DNA. ORC1 sites were universally associated with transcription start sites (TSSs) of coding or noncoding RNAs (ncRNAs). Transcription levels at the ORC1 sites directly correlated with replication timing, suggesting the existence of two classes of ORIs: those associated with moderate/high transcription levels (≥1 RNA copy/cell), firing in early S and mapping to the TSSs of coding RNAs; and those associated with low transcription levels (<1 RNA copy/cell), firing throughout the entire S and mapping to TSSs of ncRNAs. These findings are compatible with a scenario whereby TSS expression levels influence the efficiency of ORC1 recruitment at G(1) and the probability of firing during S.


Assuntos
Período de Replicação do DNA , Genoma Humano , Complexo de Reconhecimento de Origem/metabolismo , Origem de Replicação/genética , Transcrição Gênica , Linfócitos T CD4-Positivos , Imunoprecipitação da Cromatina , Fase G1/genética , Regulação da Expressão Gênica , Células HeLa , Humanos , Complexo de Reconhecimento de Origem/genética , Mapeamento Físico do Cromossomo , RNA não Traduzido/metabolismo , Fase S/genética , Sítio de Iniciação de Transcrição
15.
BMC Cancer ; 16: 692, 2016 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-27578032

RESUMO

BACKGROUND: Next Generation Sequencing (NGS) has become a valuable tool for molecular landscape characterization of cancer genomes, leading to a better understanding of tumor onset and progression, and opening new avenues in translational oncology. Formalin-fixed paraffin-embedded (FFPE) tissue is the method of choice for storage of clinical samples, however low quality of FFPE genomic DNA (gDNA) can limit its use for downstream applications. METHODS: To investigate the FFPE specimen suitability for NGS analysis and to establish the performance of two solution-based exome capture technologies, we compared the whole-exome sequencing (WES) data of gDNA extracted from 5 fresh frozen (FF) and 5 matched FFPE lung adenocarcinoma tissues using: SeqCap EZ Human Exome v.3.0 (Roche NimbleGen) and SureSelect XT Human All Exon v.5 (Agilent Technologies). RESULTS: Sequencing metrics on Illumina HiSeq were optimal for both exome systems and comparable among FFPE and FF samples, with a slight increase of PCR duplicates in FFPE, mainly in Roche NimbleGen libraries. Comparison of single nucleotide variants (SNVs) between FFPE-FF pairs reached overlapping values >90 % in both systems. Both WES showed high concordance with target re-sequencing data by Ion PGM™ in 22 lung-cancer genes, regardless the source of samples. Exon coverage of 623 cancer-related genes revealed high coverage efficiency of both kits, proposing WES as a valid alternative to target re-sequencing. CONCLUSIONS: High-quality and reliable data can be successfully obtained from WES of FFPE samples starting from a relatively low amount of input gDNA, suggesting the inclusion of NGS-based tests into clinical contest. In conclusion, our analysis suggests that the WES approach could be extended to a translational research context as well as to the clinic (e.g. to study rare malignancies), where the simultaneous analysis of the whole coding region of the genome may help in the detection of cancer-linked variants.


Assuntos
Adenocarcinoma/genética , DNA de Neoplasias/análise , Perfilação da Expressão Gênica/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Neoplasias Pulmonares/genética , Kit de Reagentes para Diagnóstico , Adenocarcinoma de Pulmão , Exoma , Formaldeído , Humanos , Inclusão em Parafina , Fixação de Tecidos
16.
Int J Syst Evol Microbiol ; 66(1): 450-456, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26545358

RESUMO

The name 'Mycobacterium alsiense', although reported in 2007, has not been validly published. Polyphasic characterization of three available strains of this species led us to the conclusion that they represent a distinct species within the genus Mycobacterium. The proposed novel species grows slowly and presents pale yellow-pigmented colonies. Differentiation from other mycobacteria is not feasible on the basis of biochemical and cultural features alone while genetic analysis, extended to eight housekeeping genes and one spacer region, reveals its clear distinction from all other mycobacteria. Mycobacterium asiaticum is the most closely related species on the basis of 16S rRNA gene sequences (similarity 99.3 %); the average nucleotide identity between the genomes of the two species is 80.72 %, clearly below the suggested cut-off (95-96 %). The name Mycobacterium alsense sp. nov. is proposed here for the novel species and replaces the name 'M. alsiense', ex Richter et al. 2007, given at the time of isolation of the first strain. The type strain is TB 1906T ( = DSM 45230T = CCUG 56586T).


Assuntos
Infecções por Mycobacterium/microbiologia , Mycobacterium/classificação , Filogenia , Doenças Respiratórias/microbiologia , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Ácidos Graxos/química , Humanos , Dados de Sequência Molecular , Mycobacterium/genética , Mycobacterium/isolamento & purificação , Ácidos Micólicos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
17.
Blood ; 121(8): 1265-75, 2013 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-23169781

RESUMO

The role of forkhead box P3 (FOXP3) is well-established in T-regulatory cells, but the function of transient FOXP3 expression in activated human conventional T (Tconv) cells is unknown. In the present study, we used 2 approaches to determine the role of FOXP3 in human Tconv cells. First, we obtained Tconv clones from a female subject who is hemizygous for a null mutation in FOXP3, allowing the comparison of autologous T-cell clones that do or do not express FOXP3. Second, we knocked down activation-induced FOXP3 in Tconv cells from healthy donors with small interfering RNAagainst FOXP3. We found that FOXP3-deficient Tconv cells proliferate more and produce more cytokines than wild-type Tconv cells and have differential expression of 274 genes. We also investigated the role of FOXP3 in Th1 and Th17 cells and found that the expression of activation-induced FOXP3 was higher and more sustained in Th17 cells compared with Th1 cells. Knocking down FOXP3 expression in Th17 cells significantly increased the production of IFN-γ and decreased the expression of CCR4, but had no effect on IL-17 expression. These data reveal a novel function of FOXP3 in Tconv cells and suggest that expression of this protein is important in the function of multiple CD4(+) T-cell lineages.


Assuntos
Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/fisiologia , Células Th1/fisiologia , Células Th17/fisiologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/fisiologia , Linhagem da Célula/imunologia , Proliferação de Células , Células Clonais/citologia , Células Clonais/fisiologia , Feminino , Fatores de Transcrição Forkhead/metabolismo , Regulação da Expressão Gênica/imunologia , Humanos , Interferon gama/metabolismo , Interleucina-2/metabolismo , Masculino , RNA Interferente Pequeno , Receptores CCR4/genética , Receptores CCR4/metabolismo , Células Th1/metabolismo , Células Th17/metabolismo , Transcriptoma
18.
Int J Syst Evol Microbiol ; 65(12): 4724-4729, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26420689

RESUMO

The name 'Mycobacterium angelicum' dates back to 2003 when it was suggested for a slowly growing mycobacterium isolated from freshwater angelfish. This name is revived here and the novel species is proposed on the basis of the polyphasic characterization of four strains including the original one. The four strains presented 100 % 16S rRNA gene sequence similarity with Mycobacterium szulgai but clearly differed from M. szulgai for the milky white aspect of the colonies. The sequence similarity with the type strain of M. szulgai ranged, in eight additionally investigated genetic targets, from 78.9 to 94.3 %, an evident contrast with the close relatedness that emerged at the level of 16S rRNA gene. The average nucleotide identity between the genomes of M. szulgai DSM 44166T and strain 126/5/03T (type strain of the novel species) was 92.92 %, and supported the status of independent species. The confirmation of the name Mycobacterium angelicum sp. nov. is proposed, with strain 126/5/03T ( = CIP 109313T = DSM 45057T) as the type strain.


Assuntos
Ciclídeos/microbiologia , Mycobacterium/classificação , Filogenia , Animais , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Água Doce , Japão , Dados de Sequência Molecular , Mycobacterium/genética , Mycobacterium/isolamento & purificação , Micobactérias não Tuberculosas , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
19.
Int J Syst Evol Microbiol ; 65(Pt 2): 510-515, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25389151

RESUMO

Six strains of a rapidly growing scotochromogenic mycobacterium were isolated from pulmonary specimens of independent patients. Biochemical and cultural tests were not suitable for their identification. The mycolic acid pattern analysed by HPLC was different from that of any other mycobacterium. Genotypic characterization, targeting seven housekeeping genes, revealed the presence of microheterogeneity in all of them. Different species were more closely related to the test strains in various regions: the type strain of Mycobacterium moriokaense showed 99.0 % 16S rRNA gene sequence similarity, and 91.5-96.5 % similarity for the remaining six regions. The whole genome sequences of the proposed type strain and that of M. moriokaense presented an average nucleotide identity (ANI) of 82.9 %. Phylogenetic analysis produced poorly robust trees in most genes with the exception of rpoB and sodA where Mycobacterium flavescens and Mycobacterium novocastrense were the closest species. This phylogenetic relatedness was confirmed by the tree inferred from five concatenated genes, which was very robust. The polyphasic characterization of the test strains, supported by the ANI value, demonstrates that they belong to a previously unreported species, for which the name Mycobacterium celeriflavum sp. nov. is proposed. The type strain is AFPC-000207(T) ( = DSM 46765(T) = JCM 18439(T)).


Assuntos
Infecções por Mycobacterium/microbiologia , Mycobacterium/classificação , Filogenia , Adulto , Idoso , Técnicas de Tipagem Bacteriana , Pré-Escolar , DNA Bacteriano/genética , Feminino , Genes Bacterianos , Humanos , Irã (Geográfico) , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mycobacterium/genética , Mycobacterium/isolamento & purificação , Ácidos Micólicos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Turquia
20.
J Neuroinflammation ; 10: 29, 2013 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-23432807

RESUMO

Autoinflammatory diseases are rare illnesses characterized by apparently unprovoked inflammation without high-titer auto-antibodies or antigen-specific T cells. They may cause neurological manifestations, such as meningitis and hearing loss, but they are also characterized by non-neurological manifestations. In this work we studied a 30-year-old man who had a chronic disease characterized by meningitis, progressive hearing loss, persistently raised inflammatory markers and diffuse leukoencephalopathy on brain MRI. He also suffered from chronic recurrent osteomyelitis of the mandible. The hypothesis of an autoinflammatory disease prompted us to test for the presence of mutations in interleukin-1-pathway genes and to investigate the function of this pathway in the mononuclear cells obtained from the patient. Search for mutations in genes associated with interleukin-1-pathway demonstrated a novel NLRP3 (CIAS1) mutation (p.I288M) and a previously described MEFV mutation (p.R761H), but their combination was found to be non-pathogenic. On the other hand, we uncovered a selective interleukin-6 hypersecretion within the central nervous system as the likely pathogenic mechanism. This is also supported by the response to the anti-interleukin-6-receptor monoclonal antibody tocilizumab, but not to the recombinant interleukin-1-receptor antagonist anakinra. Exome sequencing failed to identify mutations in other genes known to be involved in autoinflammatory diseases. We propose that the disease described in this patient might be a prototype of a novel category of autoinflammatory diseases characterized by prominent neurological involvement.


Assuntos
Interleucina-6/metabolismo , Meningite/diagnóstico , Meningite/metabolismo , Doenças do Sistema Nervoso/diagnóstico , Doenças do Sistema Nervoso/metabolismo , Adulto , Células Cultivadas , Doença Crônica , Doenças Hereditárias Autoinflamatórias/diagnóstico , Doenças Hereditárias Autoinflamatórias/genética , Doenças Hereditárias Autoinflamatórias/metabolismo , Humanos , Masculino , Meningite/genética , Monócitos/metabolismo , Doenças do Sistema Nervoso/genética , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA