RESUMO
The plasmacytoid dendritic cell (pDC) is vital to the coordinated action of innate and adaptive immunity. pDC development has not been unequivocally traced, nor has its transcriptional regulatory network been fully clarified. Here we confirm an essential requirement for the BCL11A transcription factor in fetal pDC development, and demonstrate this lineage-specific requirement in the adult organism. Furthermore, we identify BCL11A gene targets and provide a molecular mechanism for its action in pDC commitment. Embryonic germ-line deletion of Bcl11a revealed an absolute cellular, molecular, and functional absence of pDCs in fetal mice. In adults, deletion of Bcl11a in hematopoietic stem cells resulted in perturbed yet continued generation of progenitors, loss of downstream pDC and B-cell lineages, and persisting myeloid, conventional dendritic, and T-cell lineages. Challenge with virus resulted in a marked reduction of antiviral response in conditionally deleted adults. Genome-wide analyses of BCL11A DNA binding and expression revealed that BCL11A regulates transcription of E2-2 and other pDC differentiation modulators, including ID2 and MTG16. Our results identify BCL11A as an essential, lineage-specific factor that regulates pDC development, supporting a model wherein differentiation into pDCs represents a primed "default" pathway for common dendritic cell progenitors.
Assuntos
Proteínas de Transporte/imunologia , Diferenciação Celular/imunologia , Células Dendríticas/imunologia , Regulação da Expressão Gênica/imunologia , Redes Reguladoras de Genes/imunologia , Proteínas Nucleares/imunologia , Animais , Linfócitos B/metabolismo , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Imunoprecipitação da Cromatina , Proteínas de Ligação a DNA , Células Dendríticas/citologia , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Perfilação da Expressão Gênica , Camundongos , Camundongos Knockout , Camundongos Mutantes , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Repressoras , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Real-time PCR methods for detecting foodborne pathogens offer the advantages of simplicity and quick time to results compared to traditional culture methods. The addition of a recirculating pooled immunomagnetic separation method prior to real-time PCR analysis increases processing output while reducing both cost and labor. This AOAC Research Institute method modification study validates the MicroSEQ Salmonella spp. Detection Kit [AOAC Performance Tested Method (PTM) 031001] linked with the Pathatrix 10-Pooling Salmonella spp. Kit (AOAC PTM 090203C) in diced tomatoes, chocolate, and deli ham. The Pathatrix 10-Pooling protocol represents a method modification of the enrichment portion of the MicroSEQ Salmonella spp. protocol. The results of the method modification were compared to standard cultural reference methods for diced tomatoes, chocolate, and deli ham. All three matrixes were analyzed in a paired study design. An additional set of chocolate test portions was analyzed using an alternative enrichment medium in an unpaired study design. For all matrixes tested, there were no statistically significant differences in the number of positive test portions detected by the modified candidate method compared to the appropriate reference method. The MicroSEQ Salmonella spp. protocol linked with the Pathatrix individual or 10-Pooling procedure demonstrated reliability as a rapid, simplified, method for the preparation of samples and subsequent detection of Salmonella in diced tomatoes, chocolate, and deli ham.
Assuntos
Técnicas Bacteriológicas/instrumentação , Técnicas Bacteriológicas/métodos , Microbiologia de Alimentos/métodos , Salmonella/isolamento & purificação , Animais , Técnicas Bacteriológicas/normas , Cacau/microbiologia , DNA Bacteriano/classificação , DNA Bacteriano/isolamento & purificação , Microbiologia de Alimentos/normas , Solanum lycopersicum/microbiologia , Carne/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Salmonella/genética , SuínosRESUMO
This study delineates a mechanism for antiapoptotic signaling initiated by atrial natriuretic peptide (ANP) stimulation leading to elevation of cGMP levels and subsequent nuclear accumulation of Akt kinase associated with zyxin, a cytoskeletal LIM-domain protein. Nuclear targeting of zyxin induces resistance to cell death coincident with nuclear accumulation of activated Akt. Nuclear translocation of zyxin triggered by cGMP also promotes nuclear Akt accumulation. Additional supportive evidence for nuclear accumulation of zyxin-enhancing cardiomyocyte survival includes the following: (a) promotion of zyxin nuclear localization by cardioprotective stimuli; (b) zyxin association with phospho-Akt473 induced by cardioprotective stimuli; and (c) recruitment of zyxin to the nucleus by activated nuclear-targeted Akt as well as recruitment of Akt by nuclear-targeted zyxin. Nuclear accumulation of zyxin requires both Akt activation and nuclear localization. Potentiation of cell survival is sensitive to stimulation intensity with high-level induction by ANP or cGMP signaling leading to apoptotic cell death rather than enhancing resistance to apoptotic stimuli. Myocardial nuclear accumulation of zyxin and Akt responds similarly in vivo following treatment of mice with ANP or cGMP. Thus, zyxin and activated Akt participate in a cGMP-dependent signaling cascade leading from ANP receptors to nuclear accumulation of both molecules. Nuclear accumulation of zyxin and activated Akt may represent a fundamental mechanism that facilitates nuclear-signal transduction and potentiates cell survival.
Assuntos
Fator Natriurético Atrial/farmacologia , Núcleo Celular/metabolismo , GMP Cíclico/metabolismo , Proteínas do Citoesqueleto/metabolismo , Miócitos Cardíacos/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Transporte Ativo do Núcleo Celular/genética , Animais , Animais Recém-Nascidos , Apoptose/efeitos dos fármacos , Fator Natriurético Atrial/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Células Cultivadas , Proteínas do Citoesqueleto/genética , Humanos , Camundongos , Camundongos Knockout , Miócitos Cardíacos/citologia , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , ZixinaRESUMO
BACKGROUND: Chromosomal aberrations of BCL11A at 2p16.1 have been reported in a variety of B-cell malignancies and its deficiency in mice leads to a profound block in B-cell development. RESULTS: Alternative pre-mRNA splicing of BCL11A produces multiple isoforms sharing a common N-terminus. The most abundant isoform we have identified in human lymphoid samples is BCL11A-XL, the longest transcript produced at this locus, and here we report the conservation of this major isoform and its functional characterization. We show that BCL11A-XL is a DNA-sequence-specific transcriptional repressor that associates with itself and with other BCL11A isoforms, as well as with the BCL6 proto-oncogene. Western blot data for BCL11A-XL expression coupled with data previously published for BCL6 indicates that these genes are expressed abundantly in germinal-center-derived B cells but that expression is extinguished upon terminal differentiation to the plasma cell stage. Although BCL11A-XL/BCL6 interaction can modulate BCL6 DNA binding in vitro, their heteromeric association does not alter the homomeric transcriptional properties of either on model reporter activity. BCL11A-XL partitions into the nuclear matrix and colocalizes with BCL6 in nuclear paraspeckles. CONCLUSION: We propose that the conserved N-terminus of BCL11A defines a superfamily of C2HC zinc-finger transcription factors involved in hematopoietic malignancies.
Assuntos
Proteínas de Transporte/metabolismo , Centro Germinativo/metabolismo , Linfoma de Células B/metabolismo , Matriz Nuclear/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogênicas c-bcl-6/metabolismo , Processamento Alternativo/genética , Animais , Western Blotting , Células COS , Proteínas de Transporte/análise , Proteínas de Transporte/genética , Diferenciação Celular , Linhagem Celular , Linhagem Celular Tumoral , Chlorocebus aethiops , Perfilação da Expressão Gênica , Centro Germinativo/patologia , Células HeLa , Humanos , Imunoprecipitação , Linfoma de Células B/genética , Linfoma de Células B/patologia , Camundongos , Microscopia de Fluorescência , Células NIH 3T3 , Proteínas Nucleares/análise , Proteínas Nucleares/genética , Isoformas de Proteínas/análise , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/análise , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-6/análise , Proteínas Proto-Oncogênicas c-bcl-6/genética , Proteínas RepressorasRESUMO
Real-time PCR methods for detecting foodborne pathogens offer the advantages of simplicity and quick time to results compared to traditional culture methods. The addition of a recirculating pooled immunomagnetic separation method prior to real-time PCR analysis increases processing output while reducing both cost and labor. This AOAC Research Institute method modification study validates the MicroSEQ® Salmonella spp. Detection Kit [AOAC Performance Tested Method (PTM) 031001] linked with the Pathatrix® 10-Pooling Salmonella spp. Kit (AOAC PTM 090203C) in diced tomatoes, chocolate, and deli ham. The Pathatrix 10-Pooling protocol represents a method modification of the enrichment portion of the MicroSEQ Salmonella spp. PROTOCOL: The results of the method modification were compared to standard cultural reference methods for diced tomatoes, chocolate, and deli ham. All three matrixes were analyzed in a paired study design. An additional set of chocolate test portions was analyzed using an alternative enrichment medium in an unpaired study design. For all matrixes tested, there were no statistically significant differences in the number of positive test portions detected by the modified candidate method compared to the appropriate reference method. The MicroSEQ Salmonella spp. protocol linked with the Pathatrix individual or 10-Pooling procedure demonstrated reliability as a rapid, simplified, method for the preparation of samples and subsequent detection of Salmonella in diced tomatoes, chocolate, and deli ham.
RESUMO
BACKGROUND: RNA-seq is a next generation sequencing method with a wide range of applications including single nucleotide polymorphism (SNP) detection, splice junction identification, and gene expression level measurement. However, the RNA-seq sequence data can be biased during library constructions resulting in incorrect data for SNP, splice junction, and gene expression studies. Here, we developed new library preparation methods to limit such biases. RESULTS: A whole transcriptome library prepared for the SOLiD system displayed numerous read duplications (pile-ups) and gaps in known exons. The pile-ups and gaps of the whole transcriptome library caused a loss of SNP and splice junction information and reduced the quality of gene expression results. Further, we found clear sequence biases for both 5' and 3' end reads in the whole transcriptome library. To remove this bias, RNaseIII fragmentation was replaced with heat fragmentation. For adaptor ligation, T4 Polynucleotide Kinase (T4PNK) was used following heat fragmentation. However, its kinase and phosphatase activities introduced additional sequence biases. To minimize them, we used OptiKinase before T4PNK. Our study further revealed the specific target sequences of RNaseIII and T4PNK. CONCLUSIONS: Our results suggest that the heat fragmentation removed the RNaseIII sequence bias and significantly reduced the pile-ups and gaps. OptiKinase minimized the T4PNK sequence biases and removed most of the remaining pile-ups and gaps, thus maximizing the quality of RNA-seq data.
Assuntos
Biblioteca Gênica , Polinucleotídeo 5'-Hidroxiquinase/química , Ribonuclease III/química , Análise de Sequência de RNA/métodos , Temperatura Alta , TranscriptomaRESUMO
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) binds to death receptors 4 and 5 (DR4, DR5) to transduce apoptotic signals. Conatumumab (AMG 655) is an investigational, fully human monoclonal agonist antibody (IgG(1)) to human DR5, which induces apoptosis via caspase activation. In this study, we demonstrate that conatumumab binds to DR5, activating intracellular caspases in vitro in the presence of a cross-linker. We also show that conatumumab has activity in vivo and inhibits tumor growth in colon (Colo205 and HCT-15), lung (H2122) and pancreatic (MiaPaCa2/T2) xenograft models. Conatumumab also enhances the antitumor activity of chemotherapeutics in vivo. Caspase activation in Colo205 tumors is dose-dependent and correlated with serum concentrations of conatumumab. We demonstrate for the first time that increases in serum caspase-3/7 activity and levels of M30 (neoepitope of caspase-cleaved cytokeratin-18) are linked to activation of the extrinsic apoptotic pathway using conatumumab in a preclinical model. These data suggest that conatumumab has potential as a therapeutic agent for treating patients with multiple tumor types, and that serum caspase-3/7 and M30 levels may serve as biomarkers of conatumumab activity.
Assuntos
Anticorpos Monoclonais/farmacologia , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Caspase 7/metabolismo , Neoplasias/tratamento farmacológico , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/agonistas , Animais , Linhagem Celular Tumoral , Ativação Enzimática/efeitos dos fármacos , Humanos , Camundongos , Neoplasias/enzimologia , Neoplasias/patologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Ischemia-reperfusion (I/R) has critical consequences in the heart. Recent studies on the functions of I/R-activated kinases, such as p38 mitogen-activated protein kinase (MAPK), showed that I/R injury is reduced in the hearts of transgenic mice that overexpress the p38 MAPK activator MAPK kinase 6 (MKK6). This protection may be fostered by changes in the levels of many proteins not currently known to be regulated by p38. To examine this possibility, we employed the multidimensional protein identification technology MudPIT to characterize changes in levels of proteins in MKK6 transgenic mouse hearts, focusing on proteins in mitochondria, which play key roles in mediating I/R injury in the heart. Of the 386 mitochondrial proteins identified, the levels of 58 were decreased, while only 2 were increased in the MKK6 transgenic mouse hearts. Among those that were decreased were 21 mitochondrial oxidative phosphorylation complex proteins, which was unexpected because p38 is not known to mediate such decreases. Immunoblotting verified that proteins in each of the five oxidative phosphorylation complexes were reduced in MKK6 mouse hearts. On assessing functional consequences of these reductions, we found that MKK6 mouse heart mitochondria exhibited 50% lower oxidative respiration and I/R-mediated reactive oxygen species (ROS) generation, both of which are predicted consequences of decreased oxidative phosphorylation complex proteins. Thus the cardioprotection observed in MKK6 transgenic mouse hearts may be partly due to decreased electron transport, which is potentially beneficial, because damaging ROS are known to be generated by mitochondrial complexes I and III during reoxygenation.
Assuntos
Coração/fisiologia , MAP Quinase Quinase 6/metabolismo , Fosforilação Oxidativa , Proteínas/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , MAP Quinase Quinase 6/genética , Camundongos , Camundongos Transgênicos , Mitocôndrias Cardíacas/genética , Mitocôndrias Cardíacas/metabolismo , Modelos Biológicos , Proteínas/genéticaRESUMO
The mitogen-activated protein kinases (MAPK) have been the subject of many studies to identify signaling pathways that promote cell survival or death. In cultured cardiac myocytes, p38 MAPK promotes cell survival or death depending on whether it is activated by mitogen-activated protein kinase kinase 6 (MKK6) or MKK3, respectively. The objectives of the current study were to examine the effects of MKK6-mediated p38 activation in the heart in vivo. Accordingly, we generated transgenic (TG) mice that overexpress wild type MKK6 in a cardiac-restricted manner. Although p38 was about 17-fold more active in TG than non-transgenic (NTG) mouse hearts, TG mouse hearts were morphologically and functionally similar to those of NTG littermates. However, upon transient ischemia followed by reperfusion, the MKK6 TG mouse hearts exhibited significantly better functional recovery and less injury than NTG mouse hearts. Because MKK6 increases levels of the protective small heat shock protein, alpha B-crystallin (alpha BC), in cultured cardiac myocytes, we examined alpha BC levels in the mouse hearts. The level of alpha BC was 2-fold higher in MKK6 TG than NTG mouse hearts. Moreover, ischemia followed by reperfusion induced a 6.4-fold increase in alpha BC levels in the mitochondrial fractions of TG mouse hearts but no increase in alpha BC levels in any of the other fractions analyzed. These alterations in alpha BC expression and localization suggest possible mechanisms of cardioprotection in MKK6 TG mouse hearts.