Ana Dopazo

Spanish National Centre for Cardiovascular Research, Madrid, Madrid, Spain

Are you Ana Dopazo?

Claim your profile

Publications (32)161.16 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Next-generation sequencing (NGS) is becoming one of the most widely used technologies in the field of genomics. Library preparation is one of the most critical, hands-on, and time-consuming steps in the NGS workflow. Each library must be prepared in an independent well, increasing the number of hours required for a sequencing run and the risk of human-introduced error. Automation of library preparation is the best option to avoid these problems. With this in mind, we have developed automatic genomics NGS (AG-NGS), a computing application that allows an open liquid handling platform to be transformed into a library preparation station without losing the potential of an open platform. Implementation of AG-NGS does not require programming experience, and the application has also been designed to minimize implementation costs. Automated library preparation with AG-NGS generated high-quality libraries from different samples, demonstrating its efficiency, and all quality control parameters fell within the range of optimal values.
    BioTechniques 01/2014; 56(1):28-35. · 2.40 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Hereditary Angioedema due to C1-Inhibitor deficiency (HAE types I and II) is a monogenic disease characterized by sudden, self-limited episodes of cutaneous and mucosal swelling due to local deregulation of vascular permeability. Despite its monogenic pattern of inheritance, HAE exhibits great clinical variability and low genotype/phenotype correlation among those affected, which ultimately hinders therapeutic approach and probably underlies yet unknown genetic and environmental factors. METHODS: We studied whole-genome RNA expression of PBMCs in three HAE type-I families (accounting for 40 individuals), 24 of which carry the same R472X mutation in the C1-Inhibitor gene and show large variability in terms of disease expression. Those included in this study were analyzed according to the presence of mutation and/or clinical symptoms. RESULTS: Instead of a single, common disease-associated expression pattern, we found different transcriptome signatures in two of the families studied. In one of them (referred to as DR family), symptoms correlate with the upregulation of 35 genes associated to the biological response to viral infections (including RSADs, OAS, MX and ISG pathway members) and immune response. In another pedigree (Q family), disease manifestation is linked to the upregulation of 43 genes with diverse functions, including transcription and protein folding. Moreover, symptoms-free members of the Q pedigree display relatively higher expression of 394 genes with a wide diversity of functions. CONCLUSION: We found no evidence for a common altered PBMC expression pattern linked to HAE symptoms in the three families analyzed. All the data considered, differential gene expression in PBMCs do not seem to play a significant role in the predisposition or protection against HAE in the basal -between crises- conditions analyzed. Although the RNA expression pattern associated to the response to viral infections observed in the DR family supports the idea of infectious diseases as a modifying factor for HAE severity, large-scale studies would be needed to statistically associate such expression pattern to the development of this rare disease.
    Orphanet Journal of Rare Diseases 05/2013; 8(1):77. · 4.32 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVE: Different vascular beds show differing susceptibility to the development of atherosclerosis, but the molecular mechanisms underlying these differences are incompletely understood. This study aims to identify factors that contribute to the phenotypic heterogeneity of distinct regions of the adult vasculature.Approach and Results-High-throughput mRNA profiling in adult mice reveals higher expression of the homeobox paralogous genes 6 to 10 (Hox6-10) in the athero-resistant thoracic aorta (TA) than in the athero-susceptible aortic arch (AA). Higher Hox gene expression also occurs in rat and porcine TA, and is maintained in primary smooth muscle cells isolated from TA (TA-SMCs) than in cells from AA (AA-SMCs). This region-specific homeobox gene expression pattern is also observed in human embryonic stem cells differentiated into neuroectoderm-SMCs and paraxial mesoderm-SMCs, which give rise to AA-SMCs and TA-SMCs, respectively. We also find that, compared with AA and AA-SMCs, TA and TA-SMCs have lower activity of the proinflammatory and proatherogenic transcription factor NF-κB and lower expression of NF-κB target genes, at least in part attributable to HOXA9-dependent inhibition. Conversely, NF-κB inhibits HOXA9 promoter activity and mRNA expression in SMCs. CONCLUSIONS: Our findings support a model of Hox6-10-specified positional identity in the adult vasculature that is established by embryonic cues independently of environmental factors and is conserved in different mammalian species. Differential Hox expression contributes to maintaining phenotypic differences between SMCs from athero-resistant and athero-susceptible regions, at least in part through feedback regulatory mechanisms involving inflammatory mediators, for example, reciprocal inhibition between HOXA9 and NF-κB.
    Arteriosclerosis Thrombosis and Vascular Biology 02/2013; · 6.34 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dendritic cells (DC) promote tolerance or immunity depending on their maturation state. Previous studies have revealed that DC maturation is enhanced or accelerated upon MEK-ERK signaling pathway inhibition. We have now determined the contribution of MEK-ERK activation to the profile of gene expression of human immature monocyte-derived dendritic cells (MDDC) and peripheral blood myeloid DC. ERK inhibition altered the expression of genes that mediate CCL19-directed migration (CCR7) and LDL binding (CD36, SCARB1, OLR1, CXCL16) by immature DC. Besides, ERK upregulated CCL2 expression while impaired the expression of DC maturation markers (RUNX3, ITGB7, IDO1). MEK-ERK-regulated genes exhibited an over-representation of cognate sequences for the Aryl Hydrocarbon Receptor (AhR) transcription factor, whose transcriptional and DNA-binding activities increased in MDDC upon exposure to the MEK1/2 inhibitor U0126. Therefore, MEK-ERK signaling pathway regulates antigen capture, lymph node homing and the acquisition of maturation-associated genes, and its contribution to the maintenance of the immature state of MDDC and myeloid DC is partly dependent on the activity of AhR. Since pharmacological modulation of the MEK-ERK signaling pathway has been proposed as a potential therapeutic strategy for cancer, our findings indicate that ERK inhibitors might influence anti-tumor responses through regulation of critical DC effector functions.
    Blood 02/2013; · 9.78 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Axon morphogenesis is a complex process regulated by a variety of secreted molecules, including morphogens and growth factors, resulting in the establishment of the neuronal circuitry. Our previous work demonstrated that growth factors [Neurotrophins (NT) and Hepatocyte Growth Factor (HGF)] signal through β-catenin during axon morphogenesis. HGF signaling promotes axon outgrowth and branching by inducing β-catenin phosphorylation at Y142 and transcriptional regulation of T-Cell Factor (TCF) target genes. Here, we asked which genes are regulated by HGF signaling during axon morphogenesis. An array screening indicated that HGF signaling elevates the expression of chemokines of the CC and CXC families. In line with this, CCL7, CCL20, and CXCL2 significantly increase axon outgrowth in hippocampal neurons. Experiments using blocking antibodies and chemokine receptor antagonists demonstrate that chemokines act downstream of HGF signaling during axon morphogenesis. In addition, qPCR data demonstrates that CXCL2 and CCL5 expression is stimulated by HGF through Met/b-catenin/TCF pathway. These results identify CC family members and CXCL2 chemokines as novel regulators of axon morphogenesis downstream of HGF signaling.
    Frontiers in Cellular Neuroscience 01/2013; 7:52. · 4.47 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In most clinical trials, human mesenchymal stem cells (hMSCs) are expanded in vitro before implantation. The genetic stability of human stem cells is critical for their clinical use. However, the relationship between stem-cell expansion and genetic stability is poorly understood. Here, we demonstrate that within the normal expansion period, hMSC cultures show a high percentage of aneuploid cells that progressively increases until senescence. Despite this accumulation, we show that in a heterogeneous culture the senescence-prone hMSC subpopulation has a lower proliferation potential and a higher incidence of aneuploidy than the non-senescent subpopulation. We further show that senescence is linked to a novel transcriptional signature that includes a set of genes implicated in ploidy control. Overexpression of the telomerase catalytic subunit (human telomerase reverse transcriptase, hTERT) inhibited senescence, markedly reducing the levels of aneuploidy and preventing the dysregulation of ploidy-controlling genes. hMSC-replicative senescence was accompanied by an increase in oxygen consumption rate (OCR) and oxidative stress, but in long-term cultures that overexpress hTERT, these parameters were maintained at basal levels, comparable to unmodified hMSCs at initial passages. We therefore propose that hTERT contributes to genetic stability through its classical telomere maintenance function and also by reducing the levels of oxidative stress, possibly, by controlling mitochondrial physiology. Finally, we propose that aneuploidy is a relevant factor in the induction of senescence and should be assessed in hMSCs before their clinical use.
    Cell Death & Disease 01/2013; 4:e691. · 6.04 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A large number of genes are regulated to promote brain repair following stroke. The thorough analysis of this process can help identify new markers and develop therapeutic strategies. This study analyzes gene expression following experimental stroke. A microarray study of gene expression in the core, periinfarct and contralateral cortex was performed in adult Sprague-Dawley rats (n = 60) after 24 hours (acute phase) or 3 days (delayed stage) of permanent middle cerebral artery (MCA) occlusion. Independent qRT-PCR validation (n = 12) was performed for 22 of the genes. Functional data were evaluated by Ingenuity Pathway Analysis. The number of genes differentially expressed was 2,612 (24 h) and 5,717 (3 d) in the core; and 3,505 (24 h) and 1,686 (3 d) in the periinfarct area (logFC>|1|; adjP<0.05). Expression of many neurovascular unit development genes was altered at 24 h and 3 d including HES2, OLIG2, LINGO1 and NOGO-A; chemokines like CXCL1 and CXCL12, stress-response genes like HIF-1A, and trophic factors like BDNF or BMP4. Nearly half of the detected genes (43%) had not been associated with stroke previously. This comprehensive study of gene regulation in the core and periinfarct areas at different times following permanent MCA occlusion provides new data that can be helpful in translational research.
    PLoS ONE 12/2012; · 3.73 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Cardiovascular disease (CVD) is a major cause of mortality and hospitalization worldwide. Several risk factors have been identified that are strongly associated with the development of CVD. However, these explain only a fraction of cases, and the focus of research into the causes underlying the unexplained risk has shifted first to genetics and more recently to genomics. A genetic contribution to CVD has long been recognized; however, with the exception of certain conditions that show Mendelian inheritance, it has proved more challenging than anticipated to identify the precise genomic components responsible for the development of CVD. Genome-wide association studies (GWAS) have provided information about specific genetic variations associated with disease, but these are only now beginning to reveal the underlying molecular mechanisms. To fully understand the biological implications of these associations, we need to relate them to the exquisite, multilayered regulation of protein expression, which includes chromatin remodeling, regulatory elements, microRNAs and alternative splicing. Understanding how the information contained in the DNA relates to the operation of these regulatory layers will allow us not only to better predict the development of CVD but also to develop more effective therapies.
    Disease Models and Mechanisms 07/2012; 5(4):434-43. · 4.96 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The transcriptional response driven by Hypoxia-inducible factor (HIF) is central to the adaptation to oxygen restriction. Despite recent characterization of genome-wide HIF DNA binding locations and hypoxia-regulated transcripts in different cell types, the molecular bases of HIF target selection remain unresolved. Herein, we combined multi-level experimental data and computational predictions to identify sequence motifs that may contribute to HIF target selectivity. We obtained a core set of bona fide HIF binding regions by integrating multiple HIF1 DNA binding and hypoxia expression profiling datasets. This core set exhibits evolutionarily conserved binding regions and is enriched in functional responses to hypoxia. Computational prediction of enriched transcription factor binding sites identified sequence motifs corresponding to several stress-responsive transcription factors, such as activator protein 1 (AP1), cAMP response element-binding (CREB), or CCAAT-enhancer binding protein (CEBP). Experimental validations on HIF-regulated promoters suggest a functional role of the identified motifs in modulating HIF-mediated transcription. Accordingly, transcriptional targets of these factors are over-represented in a sorted list of hypoxia-regulated genes. Altogether, our results implicate cooperativity among stress-responsive transcription factors in fine-tuning the HIF transcriptional response.
    PLoS ONE 01/2012; 7(9):e45708. · 3.73 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The progression towards type 2 diabetes depends on the allostatic response of pancreatic beta cells to synthesise and secrete enough insulin to compensate for insulin resistance. The endocrine pancreas is a plastic tissue able to expand or regress in response to the requirements imposed by physiological and pathophysiological states associated to insulin resistance such as pregnancy, obesity or ageing, but the mechanisms mediating beta cell mass expansion in these scenarios are not well defined. We have recently shown that ob/ob mice with genetic ablation of PPARγ2, a mouse model known as the POKO mouse failed to expand its beta cell mass. This phenotype contrasted with the appropriate expansion of the beta cell mass observed in their obese littermate ob/ob mice. Thus, comparison of these models islets particularly at early ages could provide some new insights on early PPARγ dependent transcriptional responses involved in the process of beta cell mass expansion Here we have investigated PPARγ dependent transcriptional responses occurring during the early stages of beta cell adaptation to insulin resistance in wild type, ob/ob, PPARγ2 KO and POKO mice. We have identified genes known to regulate both the rate of proliferation and the survival signals of beta cells. Moreover we have also identified new pathways induced in ob/ob islets that remained unchanged in POKO islets, suggesting an important role for PPARγ in maintenance/activation of mechanisms essential for the continued function of the beta cell. Our data suggest that the expansion of beta cell mass observed in ob/ob islets is associated with the activation of an immune response that fails to occur in POKO islets. We have also indentified other PPARγ dependent differentially regulated pathways including cholesterol biosynthesis, apoptosis through TGF-β signaling and decreased oxidative phosphorylation.
    BMC Medical Genomics 12/2011; 4:86. · 3.47 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Expansion of human stem cells before cell therapy is typically performed at 20% O(2). Growth in these pro-oxidative conditions can lead to oxidative stress and genetic instability. Here, we demonstrate that culture of human mesenchymal stem cells at lower, physiological O(2) concentrations significantly increases lifespan, limiting oxidative stress, DNA damage, telomere shortening and chromosomal aberrations. Our gene expression and bioenergetic data strongly suggest that growth at reduced oxygen tensions favors a natural metabolic state of increased glycolysis and reduced oxidative phosphorylation. We propose that this balance is disturbed at 20% O(2), resulting in abnormally increased levels of oxidative stress. These observations indicate that bioenergetic pathways are intertwined with the control of lifespan and decisively influence the genetic stability of human primary stem cells. We conclude that stem cells for human therapy should be grown under low oxygen conditions to increase biosafety.
    Cell death and differentiation 12/2011; 19(5):743-55. · 8.24 Impact Factor
  • G Kauselmann, A Dopazo, W Link
    [Show abstract] [Hide abstract]
    ABSTRACT: The current paradigm for cancer therapy is undergoing a change from non-specific cytotoxic agents to more specific approaches based on unique molecular features of cancer cells. The identification and validation of disease relevant targets are crucial for the development of molecularly targeted anticancer therapies. Advances in our understanding of the molecular basis of cancer together with novel approaches to interfere with signal transduction pathways have opened new horizons for anticancer target discovery. In particular, the image-based large scale analysis of cellular phenotypes that arise from genetic or chemical perturbations paved the way for the identification and validation of disease relevant molecular targets independent of preconceived notions of mechanistic relationships. In addition, novel and sophisticated techniques of genome manipulation allow for the use of mouse models that faithfully recapitulate critical elements of human cancer for target validation in vivo. We believe that these advances will translate into more and better validated drug targets.
    Current cancer drug targets 10/2011; 12(1):1-13. · 5.13 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The course of HIV-1 infection shows a variety of clinical phenotypes with an important involvement of host factors. We compare host gene expression patterns in CD3+ T cells from two of these phenotypes: long-term non-progressor patients (LTNP) and matched control patients with standard HIV disease progression. Array analysis revealed over-expression of 322 genes in progressors and 136 in LTNP. Up-regulated genes in progressors were mainly implicated in the regulation of DNA replication, cell cycle and DNA damage stimulus and mostly localized into cellular organelles. In contrast, most up-regulated genes in LTNP were located at the plasmatic membrane and involved in cytokine-cytokine receptor interaction, negative control of apoptosis or regulation of actin cytoskeleton. Regarding gene interactions, a higher number of viral genes interacting with cellular factors were seen in progressors. Our study offers new comparative insights related to disease status and can distinguish differentiated patterns of gene expression among clinical phenotypes.
    Virology 03/2011; 411(1):103-12. · 3.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Translocated in liposarcoma (TLS) is a poorly characterized multifunctional protein involved in the genotoxic response. TLS regulates gene expression at several steps, including splicing and mRNA transport, possibly connecting transcriptional and posttranscriptional events. AIMS: In this study we aimed to idenfity molecular targets and regulatory partners of TLS. RESULTS AND INNOVATION: Here we report that TLS transcriptionally regulates the expression of oxidative stress protection genes. This regulation requires interaction with the transcriptional coactivator peroxisome proliferator activated receptor γ-coactivator 1α (PGC-1α), a master regulator of mitochondrial function that coordinately induces the expression of genes involved in detoxification of mitochondrial reactive oxygen species (ROS). Microarray gene expression analysis showed that TLS transcriptional activity is impaired in the absence of PGC-1α, and is thus largely dependent on PGC-1α. CONCLUSION: These results suggest the existence of a regulatory circuit linking the control of ROS detoxification to the coordinated cross-talk between oxidative metabolism and the cellular response to genomic DNA damage.
    Antioxidants & Redox Signaling 02/2011; 15(2):325-37. · 8.20 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Transcriptomics has played an essential role as proof of concept in the development of experimental and bioinformatics approaches for the generation and analysis of Omics data. We are giving an introduction on how large-scale technologies for gene expression profiling, especially microarrays, have changed the view from studying single molecular events to a systems level view of global mechanisms in a cell, the biological processes, and their pathological mutations. The main platforms available for gene expression profiling (from microarrays to RNA-seq) are presented and the general concepts that need to be taken into account for proper data analysis in order to extract objective and general conclusions from transcriptomics experiments are introduced. We also describe the available main bioinformatics resources used for this purpose.
    Methods in molecular biology (Clifton, N.J.) 01/2011; 719:269-98. · 1.29 Impact Factor
  • Molecular Immunology - MOL IMMUNOL. 01/2011; 48(14):1682-1683.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Quantitative PCR (qPCR) remains the method of choice for gene and microRNA (miRNA) expression studies. Many laboratories wish to automate some or all of the steps of medium-throughput qPCR experiments through the use of various types of liquid handling robots. However, it is not uncommon to find cases in which scripts provided by the robot supplier are too rigid for user-specific applications, do not include all the desired options, or are too complicated to be modified by a nonprofessional programmer. Here, we present Automatic Genomics, a program that allows users with a limited programming background to automate medium-throughput qPCR experiments by using commercially available liquid-handling robots. The user is able to optimize the plate design in terms of number of genes, number of samples, and controls.
    BioTechniques 01/2011; 50(1):46-50. · 2.40 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Neurogenin3, a proneural transcription factor controlled by Notch receptor, has been recently shown to regulate dendritogenesis and synaptogenesis in mouse hippocampal neurons. However, little is known about the molecular mechanisms involved in these actions of Ngn3. We have used a microarray analysis to identify Ngn3 regulated genes related with cytoskeleton dynamics. One of such genes is Fmn1, whose protein, Formin1, is associated with actin and microtubule cytoskeleton. Overexpression of the Fmn1 isoform-Ib in cultured mouse hippocampal neurons induced an increase in the number of primary dendrites and in the number of glutamatergic synaptic inputs at 4 days in vitro. The same changes were provoked by overexpression of Ngn3. In addition downregulation of Fmn1 by the use of Fmn1-siRNAs impaired such morphological and synaptic changes induced by Ngn3 overexpression in neurons. These results reveal a previously unknown involvement of Formin1 in dendritogenesis and synaptogenesis and indicate that this protein is a key component of the Ngn3 signaling pathway that controls neuronal differentiation.
    PLoS ONE 01/2011; 6(7):e21825. · 3.73 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In spite of the extensive potential of human mesenchymal stem cells (hMSCs) in cell therapy, little is known about the molecular mechanisms that regulate their therapeutic properties. We aimed to identify microRNAs (miRNAs) involved in controlling the transition between the resting and reparative phenotypes of hMSCs, hypothesizing that these miRNAs must be present in the undifferentiated cells and downregulated to allow initiation of distinct activation/differentiation programs. Differential miRNA expression analyses revealed that miR-335 is significantly downregulated upon hMSC differentiation. In addition, hMSCs derived from a variety of tissues express miR-335 at a higher level than human skin fibroblasts, and overexpression of miR-335 in hMSCs inhibited their proliferation and migration, as well as their osteogenic and adipogenic potential. Expression of miR-335 in hMSCs was upregulated by the canonical Wnt signaling pathway, a positive regulator of MSC self-renewal, and downregulated by interferon-γ (IFN-γ), a pro-inflammatory cytokine that has an important role in activating the immunomodulatory properties of hMSCs. Differential gene expression analyses, in combination with computational searches, defined a cluster of 62 putative target genes for miR-335 in hMSCs. Western blot and 3′UTR reporter assays confirmed RUNX2 as a direct target of miR-335 in hMSCs. These results strongly suggest that miR-335 downregulation is critical for the acquisition of reparative MSC phenotypes.Keywords: microRNA; mesenchymal stem cell; cell proliferation; cell migration; cell differentiation; osteogenesis
    Cell Death and Differentiation 12/2010; 18(6):985-995. · 8.37 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Dendrite branching and spine formation determines the function of morphologically distinct and specialized neuronal subclasses. However, little is known about the programs instructing specific branching patterns in vertebrate neurons and whether such programs influence dendritic spines and synapses. Using knockout and knockdown studies combined with morphological, molecular, and electrophysiological analysis, we show that the homeobox Cux1 and Cux2 are intrinsic and complementary regulators of dendrite branching, spine development, and synapse formation in layer II-III neurons of the cerebral cortex. Cux genes control the number and maturation of dendritic spines partly through direct regulation of the expression of Xlr3b and Xlr4b, chromatin remodeling genes previously implicated in cognitive defects. Accordingly, abnormal dendrites and synapses in Cux2(-/-) mice correlate with reduced synaptic function and defects in working memory. These demonstrate critical roles of Cux in dendritogenesis and highlight subclass-specific mechanisms of synapse regulation that contribute to the establishment of cognitive circuits.
    Neuron 05/2010; 66(4):523-35. · 15.77 Impact Factor