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The American lobster, Homarus americanus, is integral to marine ecosystems and supports an important commercial fishery. This iconic species also serves as a valuable model for deciphering neural networks controlling rhythmic motor patterns and olfaction. Here, we report a high-quality draft assembly of the H. americanus genome with 25,284 predicted gene models. Analysis of the neural gene complement revealed extraordinary development of the chemosensory machinery, including a profound diversification of ligand-gated ion channels and secretory molecules. The discovery of a novel class of chimeric receptors coupling pattern recognition and neurotransmitter binding suggests a deep integration between the neural and immune systems. A robust repertoire of genes involved in innate immunity, genome stability, cell survival, chemical defense, and cuticle formation represents a diversity of defense mechanisms essential to thrive in the benthic marine environment. Together, these unique evolutionary adaptations contribute to the longevity and ecological success of this long-lived benthic predator.
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Longevidad , Nephropidae , Animales , Ecosistema , Longevidad/genética , Nephropidae/genética , Nephropidae/metabolismo , Sistema NerviosoRESUMEN
Contemporary biomedical databases include a wide range of information types from various observational and instrumental sources. Among the most important features that unite biomedical databases across the field are high volume of information and high potential to cause damage through data corruption, loss of performance, and loss of patient privacy. Thus, issues of data governance and privacy protection are essential for the construction of data depositories for biomedical research and healthcare. In this paper, we discuss various challenges of data governance in the context of population genome projects. The various challenges along with best practices and current research efforts are discussed through the steps of data collection, storage, sharing, analysis, and knowledge dissemination.
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Investigación Biomédica/tendencias , Bases de Datos Genéticas , Genómica , HumanosRESUMEN
BACKGROUND: Oscillations of different origin, period and amplitude play an important role in the regulation of cellular processes. Most widely studied is the circadian or approximately daily variation in gene expression activity. Timing of gene expression is controlled by internal molecular clock keeping steady periodic expression. In this study, we shift attention towards a broad range of periodically expressed genes involved in multiple cellular functions which may or may not be under direct control of the intrinsic circadian clock. Are all molecular functions represented in expressed genes at all times? Alternatively, are different molecular functions performed at different times? Is there a pattern of succession for molecular processes and functions throughout their daily activity period? RESULTS: To answer these questions, we re-analyzed a number of mouse circadian gene expression data available from public sources. These data represent the normal function of metabolically active peripheral tissues (white adipose tissue, brown adipose tissue, liver). We applied novel methods for the estimation of confidence in phase assignment to identify groups of synchronous genes peaking at the same time regardless of the amplitude or the absolute intensity of expression. Each synchronous group has been annotated to identify Gene Ontology (GO) terms and molecular pathways. Our analysis identified molecular functions specific to a particular time of the day in different tissues. CONCLUSION: Improved methodology for datamining allowed for the discovery of functions and biological pathways in groups of genes with synchronized peak expression time. In particular, such functions as oxidative phase of energy metabolism, DNA repair, mRNA processing, lipid biosynthesis and others are separated in time. This timewise compartmentalization is important for understanding the cellular circuitry and can be used to optimize the time of intervention with drug or genome medication.
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Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/metabolismo , Biomarcadores/metabolismo , Ritmo Circadiano/fisiología , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Hígado/metabolismo , Animales , RatonesRESUMEN
BACKGROUND: Alternative transcription is common in eukaryotic cells and plays important role in regulation of cellular processes. Alternative polyadenylation results from ambiguous PolyA signals in 3' untranslated region (UTR) of a gene. Such alternative transcripts share the same coding part, but differ by a stretch of UTR that may contain important functional sites. METHODS: The methodoogy of this study is based on mathematical modeling, analytical solution, and subsequent validation by datamining in multiple independent experimental data from previously published studies. RESULTS: In this study we propose a mathematical model that describes the population dynamics of alternatively polyadenylated transcripts in conjunction with rhythmic expression such as transcription oscillation driven by circadian or metabolic oscillators. Analysis of the model shows that alternative transcripts with different turnover rates acquire a phase shift if the transcript decay rate is different. Difference in decay rate is one of the consequences of alternative polyadenylation. Phase shift can reach values equal to half the period of oscillation, which makes alternative transcripts oscillate in abundance in counter-phase to each other. Since counter-phased transcripts share the coding part, the rate of translation becomes constant. We have analyzed a few data sets collected in circadian timeline for the occurrence of transcript behavior that fits the mathematical model. CONCLUSION: Alternative transcripts with different turnover rate create the effect of rectifier. This "molecular diode" moderates or completely eliminates oscillation of individual transcripts and stabilizes overall protein production rate. In our observation this phenomenon is very common in different tissues in plants, mice, and humans. The occurrence of counter-phased alternative transcripts is also tissue-specific and affects functions of multiple biological pathways. Accounting for this mechanism is important for understanding the natural and engineering the synthetic cellular circuits.
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Ritmo Circadiano/genética , Perfilación de la Expresión Génica , Poliadenilación/genética , Animales , Humanos , Ratones , Modelos BiológicosRESUMEN
Transcriptomes are one of the first sources of high-throughput genomic data that have benefitted from the introduction of Next-Gen Sequencing. As sequencing technology becomes more accessible, transcriptome sequencing is applicable to multiple organisms for which genome sequences are unavailable. Currently all methods for de novo assembly are based on the concept of matching the nucleotide context overlapping between short fragments-reads. However, even short reads may still contain biologically relevant information which can be used as hints in guiding the assembly process. We propose a computational workflow for the reconstruction and functional annotation of expressed gene transcripts that does not require a reference genome sequence and can be tolerant to low coverage, high error rates and other issues that often lead to poor results of de novo assembly in studies of non-model organisms. We start with either raw sequences or the output of a context-based de novo transcriptome assembly. Instead of mapping reads to a reference genome or creating a completely unsupervised clustering of reads, we assemble the unknown transcriptome using nearest homologs from a public database as seeds. We consider even distant relations, indirectly linking protein-coding fragments to entire gene families in multiple distantly related genomes. The intended application of the proposed method is an additional step of semantic (based on relations between protein-coding fragments) scaffolding following traditional (i.e. based on sequence overlap) de novo assembly. The method we developed was effective in analysis of the jellyfish Cyanea capillata transcriptome and may be applicable in other studies of gene expression in species lacking a high quality reference genome sequence. Our algorithms are implemented in C and designed for parallel computation using a high-performance computer. The software is available free of charge via an open source license.
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Genoma , ARN/genética , Análisis de Secuencia de ARN/métodos , Algoritmos , TranscriptomaRESUMEN
Diverse cell types have unique transcriptional signatures that are best interrogated at single-cell resolution. Here we describe a novel RNA amplification approach that allows for high fidelity gene profiling of individual cells. This technique significantly diminishes the problem of 3' bias, enabling detection of all regions of transcripts, including the recognition of mRNA with short or completely absent poly(A) tails, identification of noncoding RNAs, and discovery of the full array of splice isoforms from any given gene product. We assess this technique using statistical and bioinformatics analyses of microarray data to establish the limitations of the method. To demonstrate applicability, we profiled individual cells isolated from the mouse subventricular zone (SVZ)-a well-characterized, discrete yet highly heterogeneous neural structure involved in persistent neurogenesis. Importantly, this method revealed multiple splice variants of key germinal zone gene products within individual cells, as well as an unexpected coexpression of several mRNAs considered markers of distinct and separate SVZ cell types. These findings were independently confirmed using RNA-fluorescence in situ hybridization (RNA-FISH), contributing to the utility of this new technology that offers genomic and transcriptomic analysis of small numbers of dynamic and clinically relevant cells.
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Perfilación de la Expresión Génica/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , ARN/genética , Análisis de la Célula Individual/métodos , Antígeno AC133 , Animales , Antígenos CD/genética , Línea Celular Tumoral , Proteínas de Unión al ADN , Receptores ErbB/genética , Proteínas del Ojo/genética , Proteína Ácida Fibrilar de la Glía/genética , Glicoproteínas/genética , Proteínas Fluorescentes Verdes/genética , Proteínas de Homeodominio/genética , Humanos , Proteína 1 Inhibidora de la Diferenciación/genética , Ventrículos Laterales/citología , Proteínas de la Membrana/genética , Ratones Transgénicos , Proteínas del Tejido Nervioso/genética , Proteínas Nucleares/genética , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box/genética , Péptidos/genética , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Proteínas Represoras/genéticaRESUMEN
Circadian oscillation in baseline gene expression plays an important role in the regulation of multiple cellular processes. Most of the knowledge of circadian gene expression is based on studies measuring gene expression over time. Our ability to dissect molecular events in time is determined by the sampling frequency of such experiments. However, the real peaks of gene activity can be at any time on or between the time points at which samples are collected. Thus, some genes with a peak activity near the observation point have their phase of oscillation detected with better precision then those which peak between observation time points. Separating genes for which we can confidently identify peak activity from ambiguous genes can improve the analysis of time series gene expression. In this study we propose a new statistical method to quantify the phase confidence of circadian genes. The numerical performance of the proposed method has been tested using three real gene expression data sets.
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Tejido Adiposo Pardo/metabolismo , Tejido Adiposo Blanco/metabolismo , Ritmo Circadiano/genética , Perfilación de la Expresión Génica/métodos , Hígado/metabolismo , Algoritmos , Animales , Ratones , Modelos Genéticos , Reproducibilidad de los Resultados , Factores de TiempoRESUMEN
The origins of neural systems remain unresolved. In contrast to other basal metazoans, ctenophores (comb jellies) have both complex nervous and mesoderm-derived muscular systems. These holoplanktonic predators also have sophisticated ciliated locomotion, behaviour and distinct development. Here we present the draft genome of Pleurobrachia bachei, Pacific sea gooseberry, together with ten other ctenophore transcriptomes, and show that they are remarkably distinct from other animal genomes in their content of neurogenic, immune and developmental genes. Our integrative analyses place Ctenophora as the earliest lineage within Metazoa. This hypothesis is supported by comparative analysis of multiple gene families, including the apparent absence of HOX genes, canonical microRNA machinery, and reduced immune complement in ctenophores. Although two distinct nervous systems are well recognized in ctenophores, many bilaterian neuron-specific genes and genes of 'classical' neurotransmitter pathways either are absent or, if present, are not expressed in neurons. Our metabolomic and physiological data are consistent with the hypothesis that ctenophore neural systems, and possibly muscle specification, evolved independently from those in other animals.
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Ctenóforos/genética , Evolución Molecular , Genoma/genética , Sistema Nervioso , Animales , Ctenóforos/clasificación , Ctenóforos/inmunología , Ctenóforos/fisiología , Genes del Desarrollo , Genes Homeobox , Mesodermo/metabolismo , Metabolómica , MicroARNs , Datos de Secuencia Molecular , Músculos/fisiología , Sistema Nervioso/metabolismo , Neuronas/metabolismo , Neurotransmisores , Filogenia , Transcriptoma/genéticaRESUMEN
Biological aging alters the metabolism and volume of adipose tissue depots. Recent evidence suggests that circadian mechanisms play a role in promoting adipogenesis, obesity, and lipodystrophy. The current study compared cohorts of younger (5-9 months) and older (24-28 months) C57BL/6 mice as a function of biological age and circadian time. Advanced age significantly reduced the weight of the brown, epididymal, inguinal, and retroperitoneal adipose depots but not total body weight. The older mice reduced their physical activity by >50% and delayed their activity initiation after light offset. The expressed transcriptome in brown and white adipose depots and liver of both cohorts displayed evidence of circadian rhythmicity; however, the oscillating mRNAs differed significantly between age groups and across tissues. The amplitude of Cry1, a component of the negative arm of the circadian apparatus, and downstream regulators such as Rev-erbα were elevated in the older relative to the younger cohorts as a function of circadian time. Overall, transcript levels differed significantly for 557 (inguinal adipose), 1,016 (liver), and 1,021 (brown adipose) expressed sequences between the cohorts as a function of age. These included transcripts encoding proteins within the canonical and non-canonical Wnt pathways. Since the Wnt pathway regulates adipose stem cell differentiation and shares a critical enzyme, glycogen synthase kinase 3ß, with the circadian mechanism, the intersection between these two fundamental regulatory mechanisms merits further investigation with respect to biological aging of adipose tissues.
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Adipogénesis/fisiología , Tejido Adiposo/fisiología , Envejecimiento/fisiología , Ritmo Circadiano/fisiología , Animales , Diferenciación Celular , Modelos Animales de Enfermedad , Estudios de Seguimiento , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
BACKGROUND: Early evolution of animals led to profound changes in body plan organization, symmetry and the rise of tissue complexity including formation of muscular and nervous systems. This process was associated with massive restructuring of animal genomes as well as deletion, acquisition and rapid differentiation of genes from a common metazoan ancestor. Here, we present a simple but efficient workflow for elucidation of gene gain and gene loss within major branches of the animal kingdom. METHODS: We have designed a pipeline of sequence comparison, clustering and functional annotation using 12 major phyla as illustrative examples. Specifically, for the input we used sets of ab initio predicted gene models from the genomes of six bilaterians, three basal metazoans (Cnidaria, Placozoa, Porifera), two unicellular eukaryotes (Monosiga and Capsospora) and the green plant Arabidopsis as an out-group. Due to the large amounts of data the software required a high-performance Linux cluster. The final results can be imported into standard spreadsheet analysis software and queried for the numbers and specific sets of genes absent in specific genomes, uniquely present or shared among different taxons. RESULTS AND CONCLUSIONS: The developed software is open source and available free of charge on Open Source principles. It allows the user to address a number of specific questions regarding gene gain and gene loss in particular genomes, and user-defined groups of genomes can be formulated in a type of logical expression. For example, our analysis of 12 sequenced genomes indicated that these genomes possess at least 90,000 unique genes and gene families, suggesting enormous diversity of the genome repertoire in the animal kingdom. Approximately 9% of these gene families are shared universally (homologous) among all genomes, 53% are unique to specific taxa, and the rest are shared between two or more distantly related genomes.
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Biología Computacional/métodos , Evolución Molecular , Genómica/métodos , Programas Informáticos , Animales , Análisis por Conglomerados , Genoma , Anotación de Secuencia Molecular , Familia de Multigenes , Filogenia , Análisis de Secuencia de ADN , Flujo de TrabajoRESUMEN
Osteosarcoma (OS) is the most common primary tumor in humans and dogs affecting the skeleton, and spontaneously occurring OS in dogs serves as an extremely useful model. Unacceptable toxicities using current treatment protocols prevent further dose-intensification from being a viable option to improve patient survival and thus, novel treatment strategies must be developed. Histone deacetylase inhibitors (HDACi) have recently emerged as a promising class of therapeutics demonstrating an ability to enhance the anti-tumor activity of traditional chemotherapeutics. To date, gene expression analysis of OS cell lines treated with HDACi has not been reported, and evaluation of the resultant gene expression changes may provide insight into the mechanisms that lead to success of HDACi. Canine OS cells, treated with a clinically relevant concentration of the HDACi valproic acid (VPA), were used for expression analysis on the Affymetrix canine v2.0 genechip. Differentially expressed genes were grouped into pathways based upon functional annotation; pathway analysis was performed with MetaCore and Ingenuity Pathways Analysis software. Validation of microarray results was performed by a combination of qRT-PCR and functional/biochemical assays revealing oxidative phosphorylation, cytoskeleton remodeling, cell cycle, and ubiquitin-proteasome among those pathways most affected by HDACi. The mitomycin C-bioactivating enzyme NQ01 also demonstrated upregulation following VPA treatment, leading to synergistic reductions in cell viability. These results provide a better understanding of the mechanisms by which HDACi exert their effect in OS, and have the potential to identify biomarkers that may serve as novel targets and/or predictors of response to HDACi-containing combination therapies in OS.
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Antineoplásicos/farmacología , Neoplasias Óseas/metabolismo , Inhibidores de Histona Desacetilasas/farmacología , Osteosarcoma/metabolismo , Ácido Valproico/farmacología , Animales , Neoplasias Óseas/enzimología , Neoplasias Óseas/genética , Línea Celular Tumoral , Perros , Regulación hacia Abajo , Endotelina-1/metabolismo , Perfilación de la Expresión Génica , NAD(P)H Deshidrogenasa (Quinona)/metabolismo , Osteosarcoma/enzimología , Osteosarcoma/genética , Inhibidores de Proteasoma , Reacción en Cadena en Tiempo Real de la Polimerasa , Biología de SistemasRESUMEN
PURPOSE OF REVIEW: Over the past decade, evidence has accumulated from basic science, clinical and epidemiological studies linking circadian mechanisms to adipose tissue biology and its related comorbidities, diabetes, metabolic syndrome and obesity. This review highlights recent in-vitro and in-vivo findings from murine, human and model organism studies. RECENT FINDINGS: High-fat diets attenuate circadian mechanisms in murine adipose depots and these effects appear to be due to obesity rather than hyperglycemia. Deletion of circadian regulatory genes such as AMPK1 and nocturnin alter the circadian biology of adipose tissue. Unlike the mouse, circadian gene oscillation in human adipose tissue appears to be independent of BMI and diabetes status, suggesting that circadian mechanistic variation occurs across species. Clues for future directions in this emerging field come from studies of the hibernation and torpor state in mammals and infection models involving the Drosophila metabolic organ or 'fat body'. SUMMARY: There is a growing consensus that circadian rhythms and metabolism are tightly regulated in adipose tissue and peripheral metabolic organs. Although central mechanisms are critical, autonomous clocks exist within the adipocytes themselves. Future circadian advances are likely to result from the studies of adipose tissue-specific gene deletions.
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Tejido Adiposo/metabolismo , Tejido Adiposo/fisiopatología , Ritmo Circadiano/fisiología , Proteínas Quinasas Activadas por AMP/genética , Proteínas Quinasas Activadas por AMP/metabolismo , Adipocitos , Animales , Dieta Alta en Grasa , Drosophila/genética , Drosophila/metabolismo , Eliminación de Gen , Humanos , Ratones , Modelos Animales , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , TranscriptomaRESUMEN
BACKGROUND: We and others have previously reported that resveratrol (RSV) suppresses colon cancer cell proliferation and elevates apoptosis in vitro and/or in vivo, however molecular mechanisms are not fully elucidated. Particularly, little information is available on RSV's effects on metabolic pathways and the cell-extra cellular matrix (ECM) communication that are critical for cancer cell growth. To identify important targets of RSV, we analyzed whole protein fractions from HT-29 advanced human colon cancer cell line treated with solvent control, IGF-1 (10 nM) and RSV (150 µM) using LC/MS/MS-Mud PIT (Multidimensional Protein Identification Technology). RESULTS: Pentose phosphate pathway (PPP), a vital metabolic pathway for cell cycle progression, was elevated and suppressed by IGF-1 and RSV, respectively in the HT-29 cell line. Enzymatic assays confirmed RSV suppression of glucose-6 phosphate dehydrogenase (rate limiting) and transketolase, key enzymes of the PPP. RSV (150 µM) suppressed, whereas IGF-1 (10 nM) elevated focal adhesion complex (FAC) proteins, talin and pFAK, critical for the cell-ECM communication. Western blotting analyses confirmed the suppression or elevation of these proteins in HT-29 cancer cells treated with RSV or IGF-1, respectively. CONCLUSIONS: Proteomic analysis enabled us to establish PPP and the talin-pFAK as targets of RSV which suppress cancer cell proliferation and induce apoptosis in the colon cancer cell line HT-29. RSV (150 µM) suppressed these pathways in the presence and absence of IGF-1, suggesting its role as a chemo-preventive agent even in obese condition.
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BACKGROUND: Aedes aegypti is arguably the most studied of all mosquito species in the laboratory and is the primary vector of both Dengue and Yellow Fever flaviviruses in the field. A large number of transcriptional studies have been made in the species and these usually report transcript quantities observed at a certain age or stage of development. However, circadian oscillation is an important characteristic of gene expression in many animals and plants, modulating both their physiology and behavior. Circadian gene expression in mosquito species has been previously reported but for only a few genes directly involved in the function of the molecular clock. RESULTS: Herein we analyze the transcription profiles of 21,494 messenger RNAs using an Ae. aegypti Agilent® microarray. Transcripts were quantified in adult female heads at 24 hours and then again at 72 hours and eight subsequent time points spaced four hours apart. We document circadian rhythms in multiple molecular pathways essential for growth, development, immune response, detoxification/pesticide resistance. Circadian rhythms were also noted in ribosomal protein genes used for normalization in reverse transcribed PCR (RT-PCR) to determine transcript abundance. We report pervasive oscillations and intricate synchronization patterns relevant to all known biological pathways. CONCLUSION: These results argue strongly that transcriptional analyses either need to be made over time periods rather than confining analyses to a single time point or development stage or exceptional care needs to be made to synchronize all mosquitoes to be analyzed and compared among treatment groups.
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Aedes/genética , Relojes Circadianos/genética , Perfilación de la Expresión Génica , Animales , Femenino , Regulación de la Expresión Génica , Genes de Insecto , Cabeza , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
BACKGROUND: Small RNA (sRNA) regulatory pathways (SRRPs) are important to anti-viral defence in mosquitoes. To identify critical features of the virus infection process in Dengue serotype 2 (DENV2)-infected Ae. aegypti, we deep-sequenced small non-coding RNAs. Triplicate biological replicates were used so that rigorous statistical metrics could be applied. RESULTS: In addition to virus-derived siRNAs (20-23 nts) previously reported for other arbovirus-infected mosquitoes, we show that PIWI pathway sRNAs (piRNAs) (24-30 nts) and unusually small RNAs (usRNAs) (13-19 nts) are produced in DENV-infected mosquitoes. We demonstrate that a major catalytic enzyme of the siRNA pathway, Argonaute 2 (Ago2), co-migrates with a ~1 megadalton complex in adults prior to bloodfeeding. sRNAs were cloned and sequenced from Ago2 immunoprecipitations. Viral sRNA patterns change over the course of infection. Host sRNAs were mapped to the published aedine transcriptome and subjected to analysis using edgeR (Bioconductor). We found that sRNA profiles are altered early in DENV2 infection, and mRNA targets from mitochondrial, transcription/translation, and transport functional categories are affected. Moreover, small non-coding RNAs (ncRNAs), such as tRNAs, spliceosomal U RNAs, and snoRNAs are highly enriched in DENV-infected samples at 2 and 4 dpi. CONCLUSIONS: These data implicate the PIWI pathway in anti-viral defense. Changes to host sRNA profiles indicate that specific cellular processes are affected during DENV infection, such as mitochondrial function and ncRNA levels. Together, these data provide important progress in understanding the DENV2 infection process in Ae. aegypti.
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Aedes/genética , Aedes/virología , Virus del Dengue/patogenicidad , Interacciones Huésped-Patógeno , ARN Interferente Pequeño/genética , Animales , Dengue/genética , Virus del Dengue/genética , Perfilación de la Expresión Génica , Genes de Insecto , ARN Viral/genética , Análisis de Secuencia de ARNRESUMEN
Adipose tissue contains a heterogeneous population of mature adipocytes, endothelial cells, immune cells, pericytes, and preadipocytic stromal/stem cells. To date, a majority of proteomic analyses have focused on intact adipose tissue or isolated adipose stromal/stem cells in vitro. In this study, human subcutaneous adipose tissue from multiple depots (arm and abdomen) obtained from female donors was separated into populations of stromal vascular fraction cells and mature adipocytes. Out of 960 features detected by 2-D gel electrophoresis, a total of 200 features displayed a 2-fold up- or down-regulation relative to each cell population. The protein identity of 136 features was determined. Immunoblot analyses comparing SVF relative to adipocytes confirmed that carbonic anhydrase II was up-regulated in both adipose depots while catalase was up-regulated in the arm only. Bioinformatic analyses of the data set determined that cytoskeletal, glycogenic, glycolytic, lipid metabolic, and oxidative stress related pathways were highly represented as differentially regulated between the mature adipocytes and stromal vascular fraction cells. These findings extend previous reports in the literature with respect to the adipose tissue proteome and the consequences of adipogenesis. The proteins identified may have value as biomarkers for monitoring the physiology and pathology of cell populations within subcutaneous adipose depots.
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Adipocitos/química , Electroforesis en Gel Bidimensional/métodos , Células Endoteliales/química , Proteoma/análisis , Células del Estroma/química , Grasa Subcutánea/citología , Adulto , Anhidrasa Carbónica II/metabolismo , Diferenciación Celular , Células Cultivadas , Biología Computacional/métodos , Células Endoteliales/citología , Femenino , Humanos , Espectrometría de Masas/métodos , Persona de Mediana Edad , Fenotipo , Células Madre/química , Células Madre/citología , Células del Estroma/citologíaRESUMEN
Multiple microarray studies have documented the importance of circadian regulation of gene expression in different species under many experimental conditions. However, these reports often differ with respect to the identity and total number of oscillating genes. This review explores the interrelated questions of: How many genes are oscillating within individual tissues or systems? What are the forces that drive these oscillations? What are the methodological sources contributing to the discrepancy between estimates of gene oscillation? And finally, what are the physiological and systemic implications of oscillatory gene expression with respect to circadian molecular biology? Since this remains an evolving area of investigation, this hypothetical and speculative review also highlights the potential limitations faced by the current data in the literature relating to the novel paradigm(s) proposed.
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Ritmo Circadiano/fisiología , Regulación de la Expresión Génica/fisiología , Animales , Arabidopsis/genética , Arabidopsis/fisiología , Drosophila melanogaster/genética , Drosophila melanogaster/fisiología , Humanos , Ratones , Análisis de Secuencia por Matrices de Oligonucleótidos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/fisiologíaRESUMEN
Circadian rhythms make a critical contribution to endocrine functions that involve adipose tissue. These contributions are made at the systemic, organ and stem cell levels. The transcription factors and enzymes responsible for the maintenance of circadian rhythms in adipose depots and other peripheral tissues that are metabolically active have now been identified. Furthermore, the circadian regulation of glucose and lipid metabolism is well-established. Animal and human models provide strong evidence that disturbances in circadian pathways are associated with an increased risk of type 2 diabetes mellitus, obesity and their comorbidities. Thus, circadian mechanisms represent a novel putative target for therapy in patients with metabolic diseases.
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Tejido Adiposo/metabolismo , Relojes Circadianos/fisiología , Tejido Adiposo/fisiología , Animales , Glucosa/metabolismo , Humanos , Metabolismo de los LípidosRESUMEN
BACKGROUND: The metabolic transformation that changes Weddell seal pups born on land into aquatic animals is not only interesting for the study of general biology, but it also provides a model for the acquired and congenital muscle disorders which are associated with oxygen metabolism in skeletal muscle. However, the analysis of gene expression in seals is hampered by the lack of specific microarrays and the very limited annotation of known Weddell seal (Leptonychotes weddellii) genes. RESULTS: Muscle samples from newborn, juvenile, and adult Weddell seals were collected during an Antarctic expedition. Extracted RNA was hybridized on Affymetrix Human Expression chips. Preliminary studies showed a detectable signal from at least 7000 probe sets present in all samples and replicates. Relative expression levels for these genes was used for further analysis of the biological pathways implicated in the metabolism transformation which occurs in the transition from newborn, to juvenile, to adult seals. Cytoskeletal remodeling, WNT signaling, FAK signaling, hypoxia-induced HIF1 activation, and insulin regulation were identified as being among the most important biological pathways involved in transformation. CONCLUSION: In spite of certain losses in specificity and sensitivity, the cross-species application of gene expression microarrays is capable of solving challenging puzzles in biology. A Systems Biology approach based on gene interaction patterns can compensate adequately for the lack of species-specific genomics information.
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Envejecimiento/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Phocidae/genética , Phocidae/metabolismo , Biología de Sistemas/métodos , Animales , Perfilación de la Expresión Génica , Humanos , Estilo de VidaRESUMEN
BACKGROUND: Osteosarcoma (OSA) spontaneously arises in the appendicular skeleton of large breed dogs and shares many physiological and molecular biological characteristics with human OSA. The standard treatment for OSA in both species is amputation or limb-sparing surgery, followed by chemotherapy. Unfortunately, OSA is an aggressive cancer with a high metastatic rate. Characterization of OSA with regard to its metastatic potential and chemotherapeutic resistance will improve both prognostic capabilities and treatment modalities. METHODS: We analyzed archived primary OSA tissue from dogs treated with limb amputation followed by doxorubicin or platinum-based drug chemotherapy. Samples were selected from two groups: dogs with disease free intervals (DFI) of less than 100 days (n = 8) and greater than 300 days (n = 7). Gene expression was assessed with Affymetrix Canine 2.0 microarrays and analyzed with a two-tailed t-test. A subset of genes was confirmed using qRT-PCR and used in classification analysis to predict prognosis. Systems-based gene ontology analysis was conducted on genes selected using a standard J5 metric. The genes identified using this approach were converted to their human homologues and assigned to functional pathways using the GeneGo MetaCore platform. RESULTS: Potential biomarkers were identified using gene expression microarray analysis and 11 differentially expressed (p < 0.05) genes were validated with qRT-PCR (n = 10/group). Statistical classification models using the qRT-PCR profiles predicted patient outcomes with 100% accuracy in the training set and up to 90% accuracy upon stratified cross validation. Pathway analysis revealed alterations in pathways associated with oxidative phosphorylation, hedgehog and parathyroid hormone signaling, cAMP/Protein Kinase A (PKA) signaling, immune responses, cytoskeletal remodeling and focal adhesion. CONCLUSIONS: This profiling study has identified potential new biomarkers to predict patient outcome in OSA and new pathways that may be targeted for therapeutic intervention.