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1.
Cell ; 169(4): 736-749.e18, 2017 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-28475899

RESUMO

Immune cells in the tumor microenvironment modulate cancer progression and are attractive therapeutic targets. Macrophages and T cells are key components of the microenvironment, yet their phenotypes and relationships in this ecosystem and to clinical outcomes are ill defined. We used mass cytometry with extensive antibody panels to perform in-depth immune profiling of samples from 73 clear cell renal cell carcinoma (ccRCC) patients and five healthy controls. In 3.5 million measured cells, we identified 17 tumor-associated macrophage phenotypes, 22 T cell phenotypes, and a distinct immune composition correlated with progression-free survival, thereby presenting an in-depth human atlas of the immune tumor microenvironment in this disease. This study revealed potential biomarkers and targets for immunotherapy development and validated tools that can be used for immune profiling of other tumor types.


Assuntos
Carcinoma de Células Renais/imunologia , Carcinoma de Células Renais/patologia , Neoplasias Renais/imunologia , Neoplasias Renais/patologia , Microambiente Tumoral , Humanos , Citometria por Imagem , Tolerância Imunológica , Rim/citologia , Macrófagos/imunologia , Macrófagos/patologia , Análise de Célula Única , Linfócitos T/imunologia , Linfócitos T/patologia
2.
Cell ; 155(5): 1075-87, 2013 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-24210918

RESUMO

Pervasive transcription of eukaryotic genomes stems to a large extent from bidirectional promoters that synthesize mRNA and divergent noncoding RNA (ncRNA). Here, we show that ncRNA transcription in the yeast S. cerevisiae is globally restricted by early termination that relies on the essential RNA-binding factor Nrd1. Depletion of Nrd1 from the nucleus results in 1,526 Nrd1-unterminated transcripts (NUTs) that originate from nucleosome-depleted regions (NDRs) and can deregulate mRNA synthesis by antisense repression and transcription interference. Transcriptome-wide Nrd1-binding maps reveal divergent NUTs at most promoters and antisense NUTs in most 3' regions of genes. Nrd1 and its partner Nab3 preferentially bind RNA motifs that are depleted in mRNAs and enriched in ncRNAs and some mRNAs whose synthesis is controlled by transcription attenuation. These results define a global mechanism for transcriptome surveillance that selectively terminates ncRNA synthesis to provide promoter directionality and to suppress antisense transcription.


Assuntos
RNA Fúngico/genética , RNA não Traduzido/genética , Proteínas de Ligação a RNA/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Terminação da Transcrição Genética , Transcriptoma , Regulação para Baixo , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas , RNA Antissenso/metabolismo , Saccharomyces cerevisiae/genética
3.
Nat Methods ; 20(3): 418-423, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36585456

RESUMO

Recent advances in multiplexed imaging methods allow simultaneous detection of dozens of proteins and hundreds of RNAs, enabling deep spatial characterization of both healthy and diseased tissues. Parameters for the design of optimal multiplex imaging studies, especially those estimating how much area has to be imaged to capture all cell phenotype clusters, are lacking. Here, using a spatial transcriptomic atlas of healthy and tumor human tissues, we developed a statistical framework that determines the number and area of fields of view necessary to accurately identify all cell phenotypes that are part of a tissue. Using this strategy on imaging mass cytometry data, we identified a measurement of tissue spatial segregation that enables optimal experimental design. This strategy will enable an improved design of multiplexed imaging studies.


Assuntos
Neoplasias , Projetos de Pesquisa , Humanos , Diagnóstico por Imagem , RNA , Neoplasias/diagnóstico por imagem
4.
J Exp Child Psychol ; 243: 105915, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38555697

RESUMO

Inhibitory control develops rapidly and nonlinearly, making its accurate assessment challenging. This research investigated the developmental dynamics of accuracy and response latency in inhibitory control assessment of 3- to 6-year-old children in a longitudinal study (N = 431; 212 girls; Mage = 4.86 years, SD = 0.99) and a cross-sectional study (N = 135; 71 girls; Mage = 4.24 years, SD = 0.61). We employed a computerized Stroop task to measure inhibitory control, with fluid intelligence serving as a covariate. A growth curve analysis revealed that children who reached an accuracy threshold of 80% earlier demonstrated faster improvements in response latency. Both the cross-sectional and longitudinal findings demonstrated a positive association between response latency in the inhibitory control task and fluid intelligence, but only when participants had achieved and maintained high accuracy. These results suggest that researchers should consider response latency as an indicator of inhibitory control only in children who manage to respond accurately in an inhibitory control task.


Assuntos
Desenvolvimento Infantil , Inibição Psicológica , Inteligência , Tempo de Reação , Teste de Stroop , Humanos , Feminino , Masculino , Criança , Estudos Transversais , Estudos Longitudinais , Desenvolvimento Infantil/fisiologia , Pré-Escolar , Inteligência/fisiologia , Função Executiva/fisiologia
5.
Ophthalmologica ; 246(3-4): 227-237, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37721532

RESUMO

INTRODUCTION: Vessel-associated retinal diseases are a major cause of blindness and severe visual impairment. The identification of appropriate biomarkers is of great importance to better anticipate disease progression and establish more targeted treatment options. MicroRNAs (miRNAs) are short, single-stranded, noncoding ribonucleic acids that are involved in the posttranscriptional regulation of gene expression through hybridization with messenger RNA. The expression of certain miRNAs can be different in patients with pathological processes and can be used for the detection and differentiation of various diseases. In this study, we investigate to what extent previously in vitro identified miRNAs are present as cell-free circulating miRNAs in the serum and vitreous of human patients with and without vessel-associated retinal diseases. METHODS: Relative quantification by quantitative real-time polymerase chain reaction was used to analyze miRNA expression in patients with vessel-associated retinal diseases such as age-related macular degeneration (AMD), diabetic retinopathy (DR), and retinal vein occlusion compared with control patients. RESULTS: In serum samples, miR-29a-3p and miR-192-5p showed increased expression in patients with neovascular AMD relative to control patients. Similarly, miR-335-5p, miR-192-5p, and miR-194-5p showed increased expression in serum from patients with proliferative DR. In vitreous samples, miR-100-5p was decreased in patients with proliferative DR. Differentially expressed miRNAs showed good diagnostic accuracy in receiver operating characteristic (ROC) and area under the ROC curve analysis. CONCLUSION: The miRNAs investigated in this study may have the potential to serve as biomarkers for vessel-associated retinal diseases. Combining multiple miRNAs may enhance the predictive power of the analysis.


Assuntos
MicroRNA Circulante , Retinopatia Diabética , MicroRNAs , Degeneração Macular Exsudativa , Humanos , MicroRNA Circulante/genética , Inibidores da Angiogênese , Fator A de Crescimento do Endotélio Vascular , Acuidade Visual , MicroRNAs/genética , Biomarcadores
6.
Sensors (Basel) ; 23(23)2023 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-38067753

RESUMO

Pedestrian detection based on deep learning methods have reached great success in the past few years with several possible real-world applications including autonomous driving, robotic navigation, and video surveillance. In this work, a new neural network two-stage pedestrian detector with a new custom classification head, adding the triplet loss function to the standard bounding box regression and classification losses, is presented. This aims to improve the domain generalization capabilities of existing pedestrian detectors, by explicitly maximizing inter-class distance and minimizing intra-class distance. Triplet loss is applied to the features generated by the region proposal network, aimed at clustering together pedestrian samples in the features space. We used Faster R-CNN and Cascade R-CNN with the HRNet backbone pre-trained on ImageNet, changing the standard classification head for Faster R-CNN, and changing one of the three heads for Cascade R-CNN. The best results were obtained using a progressive training pipeline, starting from a dataset that is further away from the target domain, and progressively fine-tuning on datasets closer to the target domain. We obtained state-of-the-art results, MR-2 of 9.9, 11.0, and 36.2 for the reasonable, small, and heavy subsets on the CityPersons benchmark with outstanding performance on the heavy subset, the most difficult one.

7.
Allergy ; 77(2): 595-608, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34157151

RESUMO

BACKGROUND: Coronavirus disease-2019 (COVID-19) has been associated with cutaneous findings, some being the result of drug hypersensitivity reactions such as maculopapular drug rashes (MDR). The aim of this study was to investigate whether COVID-19 may impact the development of the MDR. METHODS: Blood and skin samples from COVID-19 patients (based on a positive nasopharyngeal PCR) suffering from MDR (COVID-MDR), healthy controls, non-COVID-19-related patients with drug rash with eosinophilia and systemic symptoms (DRESS), and MDR were analyzed. We utilized imaging mass cytometry (IMC) to characterize the cellular infiltrate in skin biopsies. Furthermore, RNA sequencing transcriptome of skin biopsy samples and high-throughput multiplexed proteomic profiling of serum were performed. RESULTS: IMC revealed by clustering analyses a more prominent, phenotypically shifted cytotoxic CD8+ T cell population and highly activated monocyte/macrophage (Mo/Mac) clusters in COVID-MDR. The RNA sequencing transcriptome demonstrated a more robust cytotoxic response in COVID-MDR skin. However, severe acute respiratory syndrome coronavirus 2 was not detected in skin biopsies at the time point of MDR diagnosis. Serum proteomic profiling of COVID-MDR patients revealed upregulation of various inflammatory mediators (IL-4, IL-5, IL-6, TNF, and IFN-γ), eosinophil and Mo/Mac -attracting chemokines (MCP-2, MCP-3, MCP-4 and CCL11). Proteomics analyses demonstrated a massive systemic cytokine storm in COVID-MDR compared with the relatively milder cytokine storm observed in DRESS, while MDR did not exhibit such features. CONCLUSION: A systemic cytokine storm may promote activation of Mo/Mac and cytotoxic CD8+ T cells in severe COVID-19 patients, which in turn may impact the development of MDR.


Assuntos
COVID-19 , Exantema , Preparações Farmacêuticas , Linfócitos T CD8-Positivos , Humanos , Proteômica , SARS-CoV-2
8.
Mar Drugs ; 20(11)2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36354999

RESUMO

Acute and chronic dermatological injuries need rapid tissue repair due to the susceptibility to infections. To effectively promote cutaneous wound recovery, it is essential to develop safe, low-cost, and affordable regenerative tools. Therefore, we aimed to identify the biological mechanisms involved in the wound healing properties of the glycosaminoglycan dermatan sulfate (DS), obtained from ascidian Styela plicata, a marine invertebrate, which in preliminary work from our group showed no toxicity and promoted a remarkable fibroblast proliferation and migration. In this study, 2,4-DS (50 µg/mL)-treated and control groups had the relative gene expression of 84 genes participating in the healing pathway evaluated. The results showed that 57% of the genes were overexpressed during treatment, 16% were underexpressed, and 9.52% were not detected. In silico analysis of metabolic interactions exhibited overexpression of genes related to: extracellular matrix organization, hemostasis, secretion of inflammatory mediators, and regulation of insulin-like growth factor transport and uptake. Furthermore, in C57BL/6 mice subjected to experimental wounds treated with 0.25% 2,4-DS, the histological parameters demonstrated a great capacity for vascular recovery. Additionally, this study confirmed that DS is a potent inducer of wound-healing cellular pathways and a promoter of neovascularization, being a natural ally in the tissue regeneration strategy.


Assuntos
Dermatan Sulfato , Urocordados , Animais , Camundongos , Dermatan Sulfato/metabolismo , Dermatan Sulfato/farmacologia , Camundongos Endogâmicos C57BL , Urocordados/metabolismo , Cicatrização , Recursos Naturais
9.
Adv Exp Med Biol ; 1335: 37-44, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33890245

RESUMO

Pulmonary metastasectomy is a well-established contribution to the cure of oligometastatic cancers, but its exact effectiveness is poorly understood. Here we report the outcomes of repeat pulmonary metastasectomy from a multicenter trial. This retrospective study included patients who underwent re-do metastasectomies between January 2010 and December 2014. The exclusion criterion was metastasectomy without curative intent. We reviewed medical files of 621 consecutive patients who underwent initial pulmonary metastasectomy. Of those, 64 patients underwent repeat metastasectomies, and these patients were included in the analysis. All the 64 patients underwent a second metastasectomy, later 35 of them underwent a third metastasectomy, 12 underwent a fourth metastasectomy, and 6 underwent a fifth metastasectomy. The total number of re-do metastasectomies was 181. The median overall survival among the patients undergoing re-do metastasectomy was 66.0 ± 3.8 months. Three and 5-year survival rates were 82.3% and 63.3%, respectively. The 5-year survival rates were 63.3% after the first, 50.9% after the second, 74.4% after the third, 83.3% after the fourth, and 60.0% after the fifth metastasectomy. We conclude that at the current stage of knowledge, there is an indication for repeat re-do metastasectomy with curative intent.


Assuntos
Neoplasias Colorretais , Neoplasias Pulmonares , Metastasectomia , Sarcoma , Humanos , Neoplasias Pulmonares/cirurgia , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento
10.
Eur J Immunol ; 49(9): 1372-1379, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31149730

RESUMO

Bone marrow (BM) stromal cells are important in the development and maintenance of cells of the immune system. Using single cell RNA sequencing, we here explore the functional and phenotypic heterogeneity of individual transcriptomes of 1167 murine BM mesenchymal stromal cells. These cells exhibit a tremendous heterogeneity of gene expression, which precludes the identification of defined subpopulations. However, according to the expression of 108 genes involved in the communication of stromal cells with hematopoietic cells, we have identified 14 non-overlapping subpopulations, with distinct cytokine or chemokine gene expression signatures. With respect to the maintenance of subsets of immune memory cells by stromal cells, we identified distinct subpopulations expressing Il7, Il15 and Tnfsf13b. Together, this study provides a comprehensive dissection of the BM stromal heterogeneity at the single cell transcriptome level and provides a basis to understand their lifestyle and their role as organizers of niches for the long-term maintenance of immune cells.


Assuntos
Células da Medula Óssea/citologia , Medula Óssea/fisiologia , Células Estromais/citologia , Transcriptoma/genética , Animais , Fator Ativador de Células B/genética , Células Cultivadas , Citocinas/genética , Células-Tronco Hematopoéticas/citologia , Interleucina-15/genética , Interleucina-7/genética , Células-Tronco Mesenquimais/citologia , Camundongos , Camundongos Endogâmicos C57BL , Análise de Sequência de RNA/métodos
11.
Nat Methods ; 14(9): 873-876, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28783155

RESUMO

Single-cell, spatially resolved omics analysis of tissues is poised to transform biomedical research and clinical practice. We have developed an open-source, computational histology topography cytometry analysis toolbox (histoCAT) to enable interactive, quantitative, and comprehensive exploration of individual cell phenotypes, cell-cell interactions, microenvironments, and morphological structures within intact tissues. We highlight the unique abilities of histoCAT through analysis of highly multiplexed mass cytometry images of human breast cancer tissues.


Assuntos
Comunicação Celular/fisiologia , Citometria de Fluxo/métodos , Imagem Molecular/métodos , Proteoma/metabolismo , Software , Análise Serial de Tecidos/métodos , Algoritmos , Interpretação de Imagem Assistida por Computador/métodos , Interface Usuário-Computador
12.
Int J Med Microbiol ; 309(1): 26-38, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30391222

RESUMO

Staphylococcus (S.) aureus is a leading cause of bacterial infection world-wide, and currently no vaccine is available for humans. Vaccine development relies heavily on clinically relevant infection models. However, the suitability of mice for S. aureus infection models has often been questioned, because experimental infection of mice with human-adapted S. aureus requires very high infection doses. Moreover, mice were not considered to be natural hosts of S. aureus. The latter has been disproven by our recent findings, showing that both laboratory mice, as well as wild small mammals including mice, voles, and shrews, are naturally colonized with S. aureus. Here, we investigated whether mouse-and vole-derived S. aureus strains show an enhanced virulence in mice as compared to the human-adapted strain Newman. Using a step-wise approach based on the bacterial genotype and in vitro assays for host adaptation, we selected the most promising candidates for murine infection models out of a total of 254 S. aureus isolates from laboratory mice as well as wild rodents and shrews. Four strains representing the clonal complexes (CC) 8, 49, and 88 (n = 2) were selected and compared to the human-adapted S. aureus strain Newman (CC8) in murine pneumonia and bacteremia models. Notably, a bank vole-derived CC49 strain, named DIP, was highly virulent in BALB/c mice in pneumonia and bacteremia models, whereas the other murine and vole strains showed virulence similar to or lower than that of Newman. At one tenth of the standard infection dose DIP induced disease severity, bacterial load and host cytokine and chemokine responses in the murine bacteremia model similar to that of Newman. In the pneumonia model, DIP was also more virulent than Newman but the effect was less pronounced. Whole genome sequencing data analysis identified a pore-forming toxin gene, lukF-PV(P83)/lukM, in DIP but not in the other tested S. aureus isolates. To conclude, the mouse-adapted S. aureus strain DIP allows a significant reduction of the inoculation dose in mice and is hence a promising tool to develop clinically more relevant infection models.


Assuntos
Modelos Animais de Doenças , Camundongos , Pneumonia/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Animais , Arvicolinae , Bacteriemia/imunologia , Bacteriemia/microbiologia , Proteínas de Bactérias/genética , Citocinas/imunologia , Feminino , Humanos , Leucocidinas/genética , Camundongos Endogâmicos BALB C , Pneumonia/imunologia , Infecções Estafilocócicas/imunologia , Staphylococcus aureus/imunologia , Staphylococcus aureus/isolamento & purificação , Virulência/genética , Sequenciamento Completo do Genoma
13.
Bioinformatics ; 33(15): 2258-2265, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28369277

RESUMO

MOTIVATION: Chromatin immunoprecipitation followed by deep sequencing (ChIP-Seq) is a widely used approach to study protein-DNA interactions. Often, the quantities of interest are the differential occupancies relative to controls, between genetic backgrounds, treatments, or combinations thereof. Current methods for differential occupancy of ChIP-Seq data rely however on binning or sliding window techniques, for which the choice of the window and bin sizes are subjective. RESULTS: Here, we present GenoGAM (Genome-wide Generalized Additive Model), which brings the well-established and flexible generalized additive models framework to genomic applications using a data parallelism strategy. We model ChIP-Seq read count frequencies as products of smooth functions along chromosomes. Smoothing parameters are objectively estimated from the data by cross-validation, eliminating ad hoc binning and windowing needed by current approaches. GenoGAM provides base-level and region-level significance testing for full factorial designs. Application to a ChIP-Seq dataset in yeast showed increased sensitivity over existing differential occupancy methods while controlling for type I error rate. By analyzing a set of DNA methylation data and illustrating an extension to a peak caller, we further demonstrate the potential of GenoGAM as a generic statistical modeling tool for genome-wide assays. AVAILABILITY AND IMPLEMENTATION: Software is available from Bioconductor: https://www.bioconductor.org/packages/release/bioc/html/GenoGAM.html . CONTACT: gagneur@in.tum.de. SUPPLEMENTARY INFORMATION: Supplementary information is available at Bioinformatics online.


Assuntos
Imunoprecipitação da Cromatina/métodos , Metilação de DNA , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Modelos Estatísticos , Software , Animais , Genômica/métodos , Humanos , Camundongos , Modelos Biológicos , Análise de Sequência de DNA/métodos , Leveduras/genética
14.
Int J Med Microbiol ; 308(6): 590-597, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28967544

RESUMO

Laboratory mice are the most commonly used animal model for Staphylococcus aureus infection studies. We have previously shown that laboratory mice from global vendors are frequently colonized with S. aureus. Laboratory mice originate from wild house mice. Hence, we investigated whether wild rodents, including house mice, as well as shrews are naturally colonized with S. aureus and whether S. aureus adapts to the wild animal host. 295 animals of ten different species were caught in different locations over four years (2012-2015) in Germany, France and the Czech Republic. 45 animals were positive for S. aureus (15.3%). Three animals were co-colonized with two different isolates, resulting in 48 S. aureus isolates in total. Positive animals were found in Germany and the Czech Republic in each studied year. The S. aureus isolates belonged to ten different spa types, which grouped into six lineages (clonal complex (CC) 49, CC88, CC130, CC1956, sequence type (ST) 890, ST3033). CC49 isolates were most abundant (17/48, 35.4%), followed by CC1956 (14/48, 29.2%) and ST890 (9/48, 18.8%). The wild animal isolates lacked certain properties that are common among human isolates, e.g., a phage-encoded immune evasion cluster, superantigen genes on mobile genetic elements and antibiotic resistance genes, which suggests long-term adaptation to the wild animal host. One CC130 isolate contained the mecC gene, implying wild rodents might be both reservoir and vector for methicillin-resistant . In conclusion, we demonstrated that wild rodents and shrews are naturally colonized with S. aureus, and that those S. aureus isolates show signs of host adaptation.


Assuntos
Animais Selvagens/microbiologia , Roedores/microbiologia , Musaranhos/microbiologia , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/isolamento & purificação , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , República Tcheca/epidemiologia , França/epidemiologia , Alemanha/epidemiologia , Staphylococcus aureus Resistente à Meticilina , Camundongos , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/veterinária , Staphylococcus aureus/classificação , Fatores de Virulência/genética
15.
Int J Med Microbiol ; 308(6): 598-606, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29174495

RESUMO

We previously reported that laboratory mice from all global vendors are frequently colonized with Staphylococcus aureus (S. aureus). Genotyping of a snap sample of murine S. aureus isolates from Charles River, US, showed that mice were predominantly colonized with methicillin-sensitive CC88 strains. Here, we expanded our view and investigated whether laboratory mice from other global animal facilities are colonized with similar strains or novel S. aureus lineages, and whether the murine S. aureus isolates show features of host adaptation. In total, we genotyped 230 S. aureus isolates from various vendor facilities of laboratory mice around the globe (Charles River facilities in the USA, Canada, France, and Germany; another US facility) and university- or company-associated breeding facilities in Germany, China and New Zealand. Spa typing was performed to analyse the clonal relationship of the isolates. Moreover, multiplex PCRs were performed for human-specific virulence factors, the immune-evasion cluster (IEC) and superantigen genes (SAg). We found a total of 58 different spa types that clustered into 15 clonal complexes (CCs). Three of these S. aureus lineages had spread globally among laboratory mice and accounted for three quarters of the isolates: CC1 (13.5%), CC15 (14.3%), and CC88 (47.0%). Compared to human colonizing isolates of the same lineages, the murine isolates frequently lacked IEC genes and SAg genes on mobile genetic elements, implying long-term adaptation to the murine host. In conclusion, laboratory mice from various vendors are colonized with host-adapted S. aureus-strains of a few lineages, predominantly the CC88 lineage. S. aureus researchers must be cautioned that S. aureus colonization might be a relevant confounder in infection and vaccination studies and are therefore advised to screen their mice before experimentation.


Assuntos
Animais de Laboratório/microbiologia , Infecções Estafilocócicas/transmissão , Staphylococcus aureus/classificação , Adaptação Fisiológica , Animais , Antibacterianos/farmacologia , Cruzamento , Canadá , China , Farmacorresistência Bacteriana/genética , França , Genótipo , Alemanha , Evasão da Resposta Imune , Staphylococcus aureus Resistente à Meticilina/genética , Camundongos , Tipagem de Sequências Multilocus , Nova Zelândia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Estados Unidos , Fatores de Virulência/genética
16.
Mol Cell ; 34(2): 212-22, 2009 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-19394298

RESUMO

Quality control pathways such as ER-associated degradation (ERAD) employ a small number of factors to specifically recognize a wide variety of protein substrates. Delineating the mechanisms of substrate selection is a principle goal in studying quality control. The Hrd1p ubiquitin ligase mediates ERAD of numerous misfolded proteins including soluble, lumenal ERAD-L and membrane-anchored ERAD-M substrates. We tested if the Hrd1p multispanning membrane domain was involved in ERAD-M specificity. In this work, we have identified site-directed membrane domain mutants of Hrd1p impaired only for ERAD-M and normal for ERAD-L. Furthermore, other Hrd1p variants were specifically deficient for degradation of individual ERAD-M substrates. Thus, the Hrd1p transmembrane region bears determinants of high specificity in the ERAD-M pathway. From in vitro and interaction studies, we suggest a model in which the Hrd1p membrane domain employs intramembrane residues to evaluate substrate misfolding, leading to selective ubiquitination of appropriate ERAD-M clients.


Assuntos
Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , Ubiquitina-Proteína Ligases/fisiologia , Transportadores de Cassetes de Ligação de ATP/metabolismo , Sequência de Aminoácidos , Substituição de Aminoácidos , Sítios de Ligação , Retículo Endoplasmático/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras , Dados de Sequência Molecular , Fenótipo , Dobramento de Proteína , Estrutura Terciária de Proteína , Canais de Translocação SEC , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/fisiologia , Especificidade por Substrato/fisiologia , Ubiquitina-Proteína Ligases/química , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação
17.
Eur J Immunol ; 45(4): 975-87, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25639669

RESUMO

It is believed that memory CD8(+) T cells are maintained in secondary lymphoid tissues, peripheral tissues, and BM by homeostatic proliferation. Their survival has been shown to be dependent on IL-7, but it is unclear where they acquire it. Here we show that in murine BM, memory CD8(+) T cells individually colocalize with IL-7(+) reticular stromal cells. The T cells are resting in terms of global transcription and do not express markers of activation, for example, 4-1BB (CD137), IL-2, or IFN-γ, despite the expression of CD69 on about 30% of the cells. Ninety-five percent of the memory CD8(+) T cells in BM are in G0 phase of cell cycle and do not express Ki-67. Less than 1% is in S/M/G2 of cell cycle, according to propidium iodide staining. While previous publications have estimated the extent of proliferation of CD8(+) memory T cells on the basis of BrdU incorporation, we show here that BrdU itself induces proliferation of CD8(+) memory T cells. Taken together, the present results suggest that CD8(+) memory T cells are maintained as resting cells in the BM in dedicated niches with their survival conditional on IL-7 receptor signaling.


Assuntos
Células da Medula Óssea/citologia , Linfócitos T CD8-Positivos/imunologia , Memória Imunológica/imunologia , Fase de Repouso do Ciclo Celular/imunologia , Células Estromais/imunologia , Animais , Antígenos CD/biossíntese , Antígenos de Diferenciação de Linfócitos T/biossíntese , Células da Medula Óssea/imunologia , Proliferação de Células , Interferon gama/biossíntese , Interleucina-2/biossíntese , Interleucina-7/imunologia , Antígeno Ki-67/biossíntese , Lectinas Tipo C/biossíntese , Camundongos , Camundongos Endogâmicos C57BL , Transcrição Gênica , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/biossíntese
19.
Environ Manage ; 58(6): 998-1014, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27650440

RESUMO

This article attempts to shed new light on prevailing puzzles of spatial scales in multi-level, participatory governance as regards the democratic legitimacy and environmental effectiveness of governance systems. We focus on the governance re-scaling by the European Water Framework Directive, which introduced new governance scales (mandated river basin management) and demands consultation of citizens and encourages 'active involvement' of stakeholders. This allows to examine whether and how re-scaling through deliberate governance interventions impacts on democratic legitimacy and effective environmental policy delivery. To guide the enquiry, this article organizes existing-partly contradictory-claims on the relation of scale, democratic legitimacy, and environmental effectiveness into three clusters of mechanisms, integrating insights from multi-level governance, social-ecological systems, and public participation. We empirically examine Water Framework Directive implementation in a comparative case study of multi-level systems in the light of the suggested mechanisms. We compare two planning areas in Germany: North Rhine Westphalia and Lower Saxony. Findings suggest that the Water Framework Directive did have some impact on institutionalizing hydrological scales and participation. Local participation appears generally both more effective and legitimate than on higher levels, pointing to the need for yet more tailored multi-level governance approaches, depending on whether environmental knowledge or advocacy is sought. We find mixed results regarding the potential of participation to bridge spatial 'misfits' between ecological and administrative scales of governance, depending on the historical institutionalization of governance on ecological scales. Polycentricity, finally, appeared somewhat favorable in effectiveness terms with some distinct differences regarding polycentricity in planning vs. polycentricity in implementation.


Assuntos
Conservação dos Recursos Naturais/métodos , Política Ambiental , Rios , Recursos Hídricos , Conservação dos Recursos Naturais/legislação & jurisprudência , Ecologia , Ecossistema , Política Ambiental/legislação & jurisprudência , Alemanha , Regulamentação Governamental
20.
J Biol Chem ; 289(25): 17446-52, 2014 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-24802753

RESUMO

RNA polymerase II (Pol II) is the central enzyme that carries out eukaryotic mRNA transcription and consists of a 10-subunit catalytic core and a subcomplex of subunits Rpb4 and Rpb7 (Rpb4/7). Rpb4/7 has been proposed to dissociate from Pol II, enter the cytoplasm, and function there in mRNA translation and degradation. Here we provide evidence that Rpb4 mainly functions in nuclear mRNA synthesis by Pol II, as well as evidence arguing against an important cytoplasmic role in mRNA degradation. We used metabolic RNA labeling and comparative Dynamic Transcriptome Analysis to show that Rpb4 deletion in Saccharomyces cerevisiae causes a drastic defect in mRNA synthesis that is compensated by down-regulation of mRNA degradation, resulting in mRNA level buffering. Deletion of Rpb4 can be rescued by covalent fusion of Rpb4 to the Pol II core subunit Rpb2, which largely restores mRNA synthesis and degradation defects caused by Rpb4 deletion. Thus, Rpb4 is a bona fide Pol II core subunit that functions mainly in mRNA synthesis.


Assuntos
RNA Polimerase II/metabolismo , Estabilidade de RNA/fisiologia , RNA Fúngico/biossíntese , RNA Mensageiro/biossíntese , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , Deleção de Genes , RNA Polimerase II/genética , RNA Fúngico/genética , RNA Mensageiro/genética , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética
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