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1.
Tree Physiol ; 43(10): 1855-1869, 2023 10 08.
Article in English | MEDLINE | ID: mdl-37418159

ABSTRACT

Metabolomics studies are becoming increasingly common for understanding how plant metabolism responds to changes in environmental conditions, genetic manipulations and treatments. Despite the recent advances in metabolomics workflow, the sample preparation process still limits the high-throughput analysis in large-scale studies. Here, we present a highly flexible robotic system that integrates liquid handling, sonication, centrifugation, solvent evaporation and sample transfer processed in 96-well plates to automatize the metabolite extraction from leaf samples. We transferred an established manual extraction protocol performed to a robotic system, and with this, we show the optimization steps required to improve reproducibility and obtain comparable results in terms of extraction efficiency and accuracy. We then tested the robotic system to analyze the metabolomes of wild-type and four transgenic silver birch (Betula pendula Roth) lines under unstressed conditions. Birch trees were engineered to overexpress the poplar (Populus × canescens) isoprene synthase and to emit various amounts of isoprene. By fitting the different isoprene emission capacities of the transgenic trees with their leaf metabolomes, we observed an isoprene-dependent upregulation of some flavonoids and other secondary metabolites as well as carbohydrates, amino acid and lipid metabolites. By contrast, the disaccharide sucrose was found to be strongly negatively correlated to isoprene emission. The presented study illustrates the power of integrating robotics to increase the sample throughput, reduce human errors and labor time, and to ensure a fully controlled, monitored and standardized sample preparation procedure. Due to its modular and flexible structure, the robotic system can be easily adapted to other extraction protocols for the analysis of various tissues or plant species to achieve high-throughput metabolomics in plant research.


Subject(s)
Betula , Populus , Humans , Betula/genetics , Betula/metabolism , Reproducibility of Results , Metabolomics , Hemiterpenes/metabolism , Butadienes/metabolism , Plant Leaves/physiology , Trees/metabolism , Populus/metabolism , Pentanes/metabolism
2.
Stem Cells ; 36(1): 55-64, 2018 01.
Article in English | MEDLINE | ID: mdl-29047185

ABSTRACT

Hematopoietic stem cells derived from pluripotent stem cells could be used as an alternative to bone marrow transplants. Deriving these has been a long-term goal for researchers. However, the success of these efforts has been limited with the cells produced able to engraft in the bone marrow of recipient animals only in very low numbers. There is evidence that defects in the migratory and homing capacity of the cells are due to mis-regulation of miRNA expression and are responsible for their failure to engraft. We compared the miRNA expression profile of hematopoietic progenitors derived from pluripotent stem cells to those derived from bone marrow and found that numerous miRNAs are too highly expressed in hematopoietic progenitors derived from pluripotent stem cells, and that most of these are inhibitors of epithelial-mesenchymal transition or metastasis (including miR-200b, miR-200c, miR-205, miR-148a, and miR-424). We hypothesize that the high expression of these factors, which promote an adherent phenotype, may be causing the defect in hematopoietic differentiation. However, inhibiting these miRNAs, individually or in multiplex, was insufficient to improve hematopoietic differentiation in vitro, suggesting that other miRNAs and/or genes may be involved in this process. Stem Cells 2018;36:55-64.


Subject(s)
Epithelial-Mesenchymal Transition/genetics , Hematopoietic Stem Cells/metabolism , MicroRNAs/genetics , Pluripotent Stem Cells/metabolism , Cell Differentiation , Down-Regulation , Humans
3.
Oncotarget ; 8(34): 56143-56157, 2017 Aug 22.
Article in English | MEDLINE | ID: mdl-28915579

ABSTRACT

BACKGROUND: The average five-year survival for non-small cell lung cancer (NSCLC) patients is approximately 15%. Emerging evidence indicates that microRNAs (miRNAs) constitute a new class of gene regulators in humans that may play an important role in tumorigenesis. Hence, there is growing interest in studying their role as possible new biomarkers whose expression is aberrant in cancer. Therefore, in this study we identified dysregulated miRNAs by next generation sequencing (NGS) and analyzed their prognostic value. METHODS: Sequencing by oligo ligation detection technology was used to identify dysregulated miRNAs in a training cohort comprising paired tumor/normal tissue samples (N = 32). We validated 22 randomly selected differentially-expressed miRNAs by quantitative real time PCR in tumor and adjacent normal tissue samples (N = 178). Kaplan-Meier survival analysis and Cox regression were used in multivariate analysis to identify independent prognostic biomarkers. RESULTS: NGS analysis revealed that 39 miRNAs were dysregulated in NSCLC: 28 were upregulated and 11 were downregulated. Twenty-two miRNAs were validated in an independent cohort. Interestingly, the group of patients with high expression of both miRNAs (miR-21high and miR-188high) showed shorter relapse-free survival (RFS) and overall survival (OS) times. Multivariate analysis confirmed that this combined signature is an independent prognostic marker for RFS and OS (p = 0.001 and p < 0.0001, respectively). CONCLUSIONS: NGS technology can specifically identify dysregulated miRNA profiles in resectable NSCLC samples. MiR-21 or miR-188 overexpression correlated with a negative prognosis, and their combined signature may represent a new independent prognostic biomarker for RFS and OS.

4.
Bioinformatics ; 32(18): 2809-16, 2016 09 15.
Article in English | MEDLINE | ID: mdl-27324197

ABSTRACT

MOTIVATION: Functional interpretation of miRNA expression data is currently done in a three step procedure: select differentially expressed miRNAs, find their target genes, and carry out gene set overrepresentation analysis Nevertheless, major limitations of this approach have already been described at the gene level, while some newer arise in the miRNA scenario.Here, we propose an enhanced methodology that builds on the well-established gene set analysis paradigm. Evidence for differential expression at the miRNA level is transferred to a gene differential inhibition score which is easily interpretable in terms of gene sets or pathways. Such transferred indexes account for the additive effect of several miRNAs targeting the same gene, and also incorporate cancellation effects between cases and controls. Together, these two desirable characteristics allow for more accurate modeling of regulatory processes. RESULTS: We analyze high-throughput sequencing data from 20 different cancer types and provide exhaustive reports of gene and Gene Ontology-term deregulation by miRNA action. AVAILABILITY AND IMPLEMENTATION: The proposed methodology was implemented in the Bioconductor library mdgsa http://bioconductor.org/packages/mdgsa For the purpose of reproducibility all of the scripts are available at https://github.com/dmontaner-papers/gsa4mirna CONTACT: : david.montaner@gmail.com SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Subject(s)
Gene Ontology , High-Throughput Nucleotide Sequencing , MicroRNAs , Computational Biology/methods , Gene Expression Profiling/methods , Gene Regulatory Networks , Humans , Neoplasms , Reproducibility of Results
5.
Stem Cells ; 34(9): 2306-17, 2016 09.
Article in English | MEDLINE | ID: mdl-27339422

ABSTRACT

Human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs) are defined as pluripotent in view of their self-renewal ability and potential to differentiate to cells of all three germ layers. Recent studies have indicated that microRNAs (miRNAs) play an important role in the maintenance of pluripotency and cell cycle regulation. We used a microarray based approach to identify miRNAs that were enriched in hESCs when compared to differentiated cells and at the same time showed significant expression changes between different phases of cell cycle. We identified 34 candidate miRNAs and performed functional studies on one of these, miR-1305, which showed the highest expression change during cell cycle transition. Overexpression of miR-1305 induced differentiation of pluripotent stem cells, increased cell apoptosis and sped up G1/S transition, while its downregulation facilitated the maintenance of pluripotency and increased cell survival. Using target prediction software and luciferase based reporter assays we identified POLR3G as a downstream target by which miR-1305 regulates the fine balance between maintenance of pluripotency and onset of differentiation. Overexpression of POLR3G rescued pluripotent stem cell differentiation induced by miR-1305 overexpression. In contrast, knock-down of POLR3G expression abolished the miR-1305-knockdown mediated enhancement of pluripotency, thus validating its role as miR-1305 target in human pluripotent stem cells. Together our data point to an important role for miR-1305 as a novel regulator of pluripotency, cell survival and cell cycle and uncovers new mechanisms and networks by which these processes are intertwined in human pluripotent stem cells. Stem Cells 2016;34:2306-2317.


Subject(s)
Apoptosis/genetics , Cell Cycle/genetics , Cell Differentiation/genetics , MicroRNAs/metabolism , Pluripotent Stem Cells/cytology , Pluripotent Stem Cells/metabolism , Gene Expression Profiling , Gene Knockdown Techniques , Humans , MicroRNAs/genetics , Models, Biological , Oligonucleotide Array Sequence Analysis , RNA Polymerase III/metabolism
6.
Stem Cells ; 34(1): 246-51, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26418476

ABSTRACT

MicroRNA (miRNAs) are short noncoding RNA molecules involved in many cellular processes and shown to play a key role in somatic cell induced reprogramming. We performed an array based screening to identify candidates that are differentially expressed between dermal skin fibroblasts (DFs) and induced pluripotent stem cells (iPSCs). We focused our investigations on miR-145 and showed that this candidate is highly expressed in DFs relative to iPSCs and significantly downregulated during reprogramming process. Inhibition of miR-145 in DFs led to the induction of "cellular plasticity" demonstrated by: (a) alteration of cell morphology associated with downregulation of mesenchymal and upregulation of epithelial markers; (b) upregulation of pluripotency-associated genes including SOX2, KLF4, C-MYC; (c) downregulation of miRNA let-7b known to inhibit reprogramming; and (iv) increased efficiency of reprogramming to iPSCs in the presence of reprogramming factors. Together, our results indicate a direct functional link between miR-145 and molecular pathways underlying reprogramming of somatic cells to iPSCs.


Subject(s)
Cellular Reprogramming , Dermis/cytology , Fibroblasts/cytology , Fibroblasts/metabolism , Induced Pluripotent Stem Cells/cytology , MicroRNAs/metabolism , Base Sequence , Cellular Reprogramming/genetics , Gene Expression Regulation , Humans , Kruppel-Like Factor 4 , MicroRNAs/genetics , Molecular Sequence Data , Reproducibility of Results
7.
Eur J Oral Sci ; 123(5): 381-384, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26331285

ABSTRACT

The etiology of cleft lip with or without cleft palate (CL±P) is complex and heterogeneous, and multiple genetic and environmental factors are involved. Some candidate genes reported to be associated with oral clefts are located on the X chromosome. At least three genes causing X-linked syndromes [midline 1 (MID1), oral-facial-digital syndrome 1 (OFD1), and dystrophin (DMD)] were previously found to be associated with isolated CL±P. We attempted to confirm the role of X-linked genes in the etiology of isolated CL±P in a South American population through a family-based genome-wide scan. We studied 27 affected children and their mothers, from 26 families, in a Patagonian population with a high prevalence of CL±P. We conducted an exploratory analysis of the X chromosome to identify candidate regions associated with CL±P. Four genomic segments were identified, two of which showed a statistically significant association with CL±P. One is an 11-kb region of Xp21.1 containing the DMD gene, and the other is an intergenic region (8.7 kb; Xp11.4). Our results are consistent with recent data on the involvement of the DMD gene in the etiology of CL±P. The MID1 and OFD1 genes were not included in the four potential CL±P-associated X-chromosome genomic segments.

8.
Nucleic Acids Res ; 43(W1): W117-21, 2015 Jul 01.
Article in English | MEDLINE | ID: mdl-25897133

ABSTRACT

Babelomics has been running for more than one decade offering a user-friendly interface for the functional analysis of gene expression and genomic data. Here we present its fifth release, which includes support for Next Generation Sequencing data including gene expression (RNA-seq), exome or genome resequencing. Babelomics has simplified its interface, being now more intuitive. Improved visualization options, such as a genome viewer as well as an interactive network viewer, have been implemented. New technical enhancements at both, client and server sides, makes the user experience faster and more dynamic. Babelomics offers user-friendly access to a full range of methods that cover: (i) primary data analysis, (ii) a variety of tests for different experimental designs and (iii) different enrichment and network analysis algorithms for the interpretation of the results of such tests in the proper functional context. In addition to the public server, local copies of Babelomics can be downloaded and installed. Babelomics is freely available at: http://www.babelomics.org.


Subject(s)
Genomics/methods , Software , Gene Expression Profiling , High-Throughput Nucleotide Sequencing , Internet , Neoplasms/genetics , Sequence Analysis, RNA
9.
Mol Immunol ; 64(2): 252-61, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25553522

ABSTRACT

Two regions of Ole e 1, the major olive-pollen allergen, have been characterized as T-cell epitopes, one as immunodominant region (aa91-130) and the other, as mainly recognized by non-allergic subjects (aa10-31). This report tries to characterize the specific relevance of these epitopes in the allergic response to olive pollen by analyzing the secreted cytokines and the gene expression profiles induced after specific stimulation of peripheral blood mononuclear cells (PBMCs). PBMCs from olive pollen-allergic and non-allergic control subjects were stimulated with olive-pollen extract and Ole e 1 dodecapeptides containing relevant T-cell epitopes. Levels of cytokines were measured in cellular supernatants and gene expression was determined by microarrays, on the RNAs extracted from PBMCs. One hundred eighty-nine differential genes (fold change >2 or <-2, P<0.05) were validated by qRT-PCR in a large population. It was not possible to define a pattern of response according the overall cytokine results but interesting differences were observed, mainly in the regulatory cytokines. Principal component (PCA) gene-expression analysis defined clusters that correlated with the experimental conditions in the group of allergic subjects. Gene expression and functional analyses revealed differential genes and pathways among the experimental conditions. A set of 51 genes (many essential to T-cell tolerance and homeostasis) correlated with the response to aa10-31 of Ole e 1. In conclusion, two peptides derived from Ole e 1 could regulate the immune response in allergic patients, by gene-expression modification of several regulation-related genes. These results open new research ways to the regulation of allergy by Oleaceae family members.


Subject(s)
Antigens, Plant/immunology , Epitopes, T-Lymphocyte/immunology , Leukocytes, Mononuclear/immunology , Oligopeptides/immunology , Plant Proteins/immunology , Pollen/immunology , Rhinitis, Allergic, Seasonal/immunology , Adult , Amino Acid Sequence , Antigens, Plant/pharmacology , Case-Control Studies , Epitopes, T-Lymphocyte/chemistry , Epitopes, T-Lymphocyte/genetics , Female , Gene Expression Profiling , Gene Expression Regulation , Genetic Markers , Humans , Immunoglobulin E/blood , Leukocytes, Mononuclear/drug effects , Leukocytes, Mononuclear/pathology , Male , Middle Aged , Molecular Sequence Data , Multigene Family , Olea/chemistry , Olea/immunology , Oligopeptides/chemical synthesis , Oligopeptides/pharmacology , Plant Proteins/pharmacology , Pollen/chemistry , Primary Cell Culture , Principal Component Analysis , Rhinitis, Allergic, Seasonal/blood , Rhinitis, Allergic, Seasonal/physiopathology
10.
BMC Syst Biol ; 8: 121, 2014 Oct 25.
Article in English | MEDLINE | ID: mdl-25344409

ABSTRACT

BACKGROUND: Understanding the aspects of the cell functionality that account for disease or drug action mechanisms is one of the main challenges in the analysis of genomic data and is on the basis of the future implementation of precision medicine. RESULTS: Here we propose a simple probabilistic model in which signaling pathways are separated into elementary sub-pathways or signal transmission circuits (which ultimately trigger cell functions) and then transforms gene expression measurements into probabilities of activation of such signal transmission circuits. Using this model, differential activation of such circuits between biological conditions can be estimated. Thus, circuit activation statuses can be interpreted as biomarkers that discriminate among the compared conditions. This type of mechanism-based biomarkers accounts for cell functional activities and can easily be associated to disease or drug action mechanisms. The accuracy of the proposed model is demonstrated with simulations and real datasets. CONCLUSIONS: The proposed model provides detailed information that enables the interpretation disease mechanisms as a consequence of the complex combinations of altered gene expression values. Moreover, it offers a framework for suggesting possible ways of therapeutic intervention in a pathologically perturbed system.


Subject(s)
Biomarkers/metabolism , Disease , Gene Expression Regulation/physiology , Models, Biological , Signal Transduction/physiology , Animals , Computer Simulation , Humans , Internet , Mice , Software , Species Specificity
11.
Hum Mutat ; 35(12): 1436-41, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25196541

ABSTRACT

Overgrowth syndromes (OGS) are a group of disorders in which all parameters of growth and physical development are above the mean for age and sex. We evaluated a series of 270 families from the Spanish Overgrowth Syndrome Registry with no known OGS. We identified one de novo deletion and three missense mutations in RNF125 in six patients from four families with overgrowth, macrocephaly, intellectual disability, mild hydrocephaly, hypoglycemia, and inflammatory diseases resembling Sjögren syndrome. RNF125 encodes an E3 ubiquitin ligase and is a novel gene of OGS. Our studies of the RNF125 pathway point to upregulation of RIG-I-IPS1-MDA5 and/or disruption of the PI3K-AKT and interferon signaling pathways as the putative final effectors.


Subject(s)
Growth Disorders/genetics , Mutation , Ubiquitin-Protein Ligases/genetics , Female , Growth Disorders/epidemiology , Humans , Male , Pedigree , Registries , Spain/epidemiology , Syndrome
12.
BMC Syst Biol ; 8 Suppl 2: S7, 2014.
Article in English | MEDLINE | ID: mdl-25032889

ABSTRACT

BACKGROUND: The development of high-throughput omics technologies enabled genome-wide measurements of the activity of cellular elements and provides the analytical resources for the progress of the Systems Biology discipline. Analysis and interpretation of gene expression data has evolved from the gene to the pathway and interaction level, i.e. from the detection of differentially expressed genes, to the establishment of gene interaction networks and the identification of enriched functional categories. Still, the understanding of biological systems requires a further level of analysis that addresses the characterization of the interaction between functional modules. RESULTS: We present a novel computational methodology to study the functional interconnections among the molecular elements of a biological system. The PANA approach uses high-throughput genomics measurements and a functional annotation scheme to extract an activity profile from each functional block -or pathway- followed by machine-learning methods to infer the relationships between these functional profiles. The result is a global, interconnected network of pathways that represents the functional cross-talk within the molecular system. We have applied this approach to describe the functional transcriptional connections during the yeast cell cycle and to identify pathways that change their connectivity in a disease condition using an Alzheimer example. CONCLUSIONS: PANA is a useful tool to deepen in our understanding of the functional interdependences that operate within complex biological systems. We show the approach is algorithmically consistent and the inferred network is well supported by the available functional data. The method allows the dissection of the molecular basis of the functional connections and we describe the different regulatory mechanisms that explain the network's topology obtained for the yeast cell cycle data.


Subject(s)
Gene Expression Profiling , Gene Regulatory Networks , Systems Biology/methods , Alzheimer Disease/genetics , Cell Cycle/genetics , DNA Replication/genetics , Gluconeogenesis/genetics , Glycolysis/genetics , Oxidative Phosphorylation , Proteolysis , Purines/metabolism , Saccharomyces cerevisiae/cytology , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/metabolism , Ubiquitin/metabolism
13.
Pediatr Res ; 75(2): 302-14, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24216542

ABSTRACT

BACKGROUND: Risk classification and treatment stratification for cancer patients is restricted by our incomplete picture of the complex and unknown interactions between the patient's organism and tumor tissues (transformed cells supported by tumor stroma). Moreover, all clinical factors and laboratory studies used to indicate treatment effectiveness and outcomes are by their nature a simplification of the biological system of cancer, and cannot yet incorporate all possible prognostic indicators. METHODS: A multiparametric analysis on 184 tumor cylinders was performed. To highlight the benefit of integrating digitized medical imaging into this field, we present the results of computational studies carried out on quantitative measurements, taken from stromal and cancer cells and various extracellular matrix fibers interpenetrated by glycosaminoglycans, and eight current approaches to risk stratification systems in patients with primary and nonprimary neuroblastoma. RESULTS: New tumor tissue indicators from both fields, the cellular and the extracellular elements, emerge as reliable prognostic markers for risk stratification and could be used as molecular targets of specific therapies. CONCLUSION: The key to dealing with personalized therapy lies in the mathematical modeling. The use of bioinformatics in patient-tumor-microenvironment data management allows a predictive model in neuroblastoma.


Subject(s)
Extracellular Matrix/pathology , Models, Theoretical , Neuroblastoma/pathology , Algorithms , Cell Line, Transformed , Child , Child, Preschool , Cluster Analysis , Computational Biology , Glycosaminoglycans/chemistry , Humans , Infant , Neoplasms/pathology , Precision Medicine , Prognosis , Risk , Stromal Cells/cytology
14.
PLoS One ; 8(4): e62135, 2013.
Article in English | MEDLINE | ID: mdl-23614026

ABSTRACT

The genetic mechanisms governing human pre-implantation embryo development and the in vitro counterparts, human embryonic stem cells (hESCs), still remain incomplete. Previous global genome studies demonstrated that totipotent blastomeres from day-3 human embryos and pluripotent inner cell masses (ICMs) from blastocysts, display unique and differing transcriptomes. Nevertheless, comparative gene expression analysis has revealed that no significant differences exist between hESCs derived from blastomeres versus those obtained from ICMs, suggesting that pluripotent hESCs involve a new developmental progression. To understand early human stages evolution, we developed an undifferentiation network signature (UNS) and applied it to a differential gene expression profile between single blastomeres from day-3 embryos, ICMs and hESCs. This allowed us to establish a unique signature composed of highly interconnected genes characteristic of totipotency (61 genes), in vivo pluripotency (20 genes), and in vitro pluripotency (107 genes), and which are also proprietary according to functional analysis. This systems biology approach has led to an improved understanding of the molecular and signaling processes governing human pre-implantation embryo development, as well as enabling us to comprehend how hESCs might adapt to in vitro culture conditions.


Subject(s)
Embryonic Development/genetics , Gene Expression Profiling , Genome, Human/genetics , Pluripotent Stem Cells/metabolism , Totipotent Stem Cells/metabolism , Blastocyst Inner Cell Mass/cytology , Blastocyst Inner Cell Mass/metabolism , Blastomeres/cytology , Blastomeres/metabolism , Cell Differentiation/genetics , Embryonic Stem Cells/cytology , Embryonic Stem Cells/metabolism , Gene Regulatory Networks/genetics , Humans , Molecular Sequence Annotation , Pluripotent Stem Cells/cytology , Totipotent Stem Cells/cytology
15.
Orphanet J Rare Dis ; 7: 103, 2012 Dec 28.
Article in English | MEDLINE | ID: mdl-23270508

ABSTRACT

Finding gene associations in rare diseases is frequently hampered by the reduced numbers of patients accessible. Conventional gene-based association tests rely on the availability of large cohorts, which constitutes a serious limitation for its application in this scenario. To overcome this problem we have used here a combined strategy in which a pathway-based analysis (PBA) has been initially conducted to prioritize candidate genes in a Spanish cohort of 53 trios of short-segment Hirschsprung's disease. Candidate genes have been further validated in an independent population of 106 trios. The study revealed a strong association of 11 gene ontology (GO) modules related to signal transduction and its regulation, enteric nervous system (ENS) formation and other HSCR-related processes. Among the preselected candidates, a total of 4 loci, RASGEF1A, IQGAP2, DLC1 and CHRNA7, related to signal transduction and migration processes, were found to be significantly associated to HSCR. Network analysis also confirms their involvement in the network of already known disease genes. This approach, based on the study of functionally-related gene sets, requires of lower sample sizes and opens new opportunities for the study of rare diseases.


Subject(s)
Genome-Wide Association Study/methods , Hirschsprung Disease/genetics , Female , Genetic Predisposition to Disease , Genotype , Humans , Male
16.
FASEB J ; 26(11): 4481-94, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22859368

ABSTRACT

The mechanism by which proteolytic events translate into biological responses is not well understood. To explore the link of pericellular proteolysis to events relevant to capillary sprouting within the inflammatory context, we aimed at the identification of the collection of substrates of the protease MT1-MMP in endothelial tip cells induced by inflammatory stimuli. We applied quantitative proteomics to endothelial cells (ECs) derived from wild-type and MT1-MMP-null mice to identify the substrate repertoire of this protease in TNF-α-activated ECs. Bioinformatics analysis revealed a combinatorial MT1-MMP proteolytic program, in which combined rather than single substrate processing would determine biological decisions by activated ECs, including chemotaxis, cell motility and adhesion, and vasculature development. MT1-MMP-deficient ECs inefficiently processed several of these substrates (TSP1, CYR61, NID1, and SEM3C), validating the model. This novel concept of MT1-MMP-driven combinatorial proteolysis in angiogenesis might be extendable to proteolytic actions in other cellular contexts.


Subject(s)
Endothelial Cells/metabolism , Matrix Metalloproteinase 14/metabolism , Animals , Blotting, Western , Combinatorial Chemistry Techniques , Computational Biology , Gene Expression Regulation, Enzymologic/physiology , Inflammation , Matrix Metalloproteinase 14/genetics , Mice , Protein Array Analysis , RNA Interference , RNA, Small Interfering , Reverse Transcriptase Polymerase Chain Reaction , Transcriptome , Tumor Necrosis Factor-alpha
17.
PLoS One ; 7(5): e35915, 2012.
Article in English | MEDLINE | ID: mdl-22574127

ABSTRACT

In this work we have described the translatome of two mammalian cell lines, NIH3T3 and Jurkat, by scoring the relative polysome association of ∼10,000 mRNA under normal and ER stress conditions. We have found that translation efficiencies of mRNA correlated poorly with transcript abundance, although a general tendency was observed so that the highest translation efficiencies were found in abundant mRNA. Despite the differences found between mouse (NIH3T3) and human (Jurkat) cells, both cell types share a common translatome composed by ∼800-900 mRNA that encode proteins involved in basic cellular functions. Upon stress, an extensive remodeling in translatomes was observed so that translation of ∼50% of mRNA was inhibited in both cell types, this effect being more dramatic for those mRNA that accounted for most of the cell translation. Interestingly, we found two subsets comprising 1000-1500 mRNA whose translation resisted or was induced by stress. Translation arrest resistant class includes many mRNA encoding aminoacyl tRNA synthetases, ATPases and enzymes involved in DNA replication and stress response such as BiP. This class of mRNA is characterized by high translation rates in both control and stress conditions. Translation inducible class includes mRNA whose translation was relieved after stress, showing a high enrichment in early response transcription factors of bZIP and zinc finger C2H2 classes. Unlike yeast, a general coordination between changes in translation and transcription upon stress (potentiation) was not observed in mammalian cells. Among the different features of mRNA analyzed, we found a relevant association of translation efficiency with the presence of upstream ATG in the 5'UTR and with the length of coding sequence of mRNA, and a looser association with other parameters such as the length and the G+C content of 5'UTR. A model for translatome remodeling during the acute phase of stress response in mammalian cells is proposed.


Subject(s)
Endoplasmic Reticulum Stress/genetics , Protein Biosynthesis , Animals , Humans , Jurkat Cells , Mice , NIH 3T3 Cells , Oligonucleotide Array Sequence Analysis , RNA, Messenger/genetics , Transcription, Genetic
18.
Hum Mol Genet ; 20(24): 4932-46, 2011 Dec 15.
Article in English | MEDLINE | ID: mdl-21937587

ABSTRACT

Understanding the transcriptional cues that direct differentiation of human embryonic stem cells (hESCs) and human-induced pluripotent stem cells to defined and functional cell types is essential for future clinical applications. In this study, we have compared transcriptional profiles of haematopoietic progenitors derived from hESCs at various developmental stages of a feeder- and serum-free differentiation method and show that the largest transcriptional changes occur during the first 4 days of differentiation. Data mining on the basis of molecular function revealed Rho-GTPase signalling as a key regulator of differentiation. Inhibition of this pathway resulted in a significant reduction in the numbers of emerging haematopoietic progenitors throughout the differentiation window, thereby uncovering a previously unappreciated role for Rho-GTPase signalling during human haematopoietic development. Our analysis indicated that SCL was the 11th most upregulated transcript during the first 4 days of the hESC differentiation process. Overexpression of SCL in hESCs promoted differentiation to meso-endodermal lineages, the emergence of haematopoietic and erythro-megakaryocytic progenitors and accelerated erythroid differentiation. Importantly, intrasplenic transplantation of SCL-overexpressing hESC-derived haematopoietic cells enhanced recovery from induced acute anaemia without significant cell engraftment, suggesting a paracrine-mediated effect.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/genetics , Cell Differentiation/genetics , Embryonic Stem Cells/cytology , Gene Expression Profiling , Hematopoietic Stem Cells/cytology , Proto-Oncogene Proteins/genetics , Transcriptome/genetics , rho GTP-Binding Proteins/metabolism , Acute Disease , Anemia, Hemolytic/genetics , Anemia, Hemolytic/pathology , Anemia, Hemolytic/therapy , Animals , Basic Helix-Loop-Helix Transcription Factors/metabolism , Cell Line , Cell Lineage/genetics , Cluster Analysis , Embryonic Stem Cells/metabolism , Erythroid Cells/cytology , Erythroid Cells/metabolism , Flow Cytometry , Hematopoietic Stem Cells/metabolism , Humans , Mice , Myeloid Cells/cytology , Paracrine Communication/genetics , Proto-Oncogene Proteins/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Signal Transduction/genetics , Stem Cell Transplantation , T-Cell Acute Lymphocytic Leukemia Protein 1 , rho GTP-Binding Proteins/genetics
19.
Diabetes ; 60(3): 797-809, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21266330

ABSTRACT

OBJECTIVE: Obesity-associated insulin resistance is characterized by a state of chronic, low-grade inflammation that is associated with the accumulation of M1 proinflammatory macrophages in adipose tissue. Although different evidence explains the mechanisms linking the expansion of adipose tissue and adipose tissue macrophage (ATM) polarization, in the current study we investigated the concept of lipid-induced toxicity as the pathogenic link that could explain the trigger of this response. RESEARCH DESIGN AND METHODS: We addressed this question using isolated ATMs and adipocytes from genetic and diet-induced murine models of obesity. Through transcriptomic and lipidomic analysis, we created a model integrating transcript and lipid species networks simultaneously occurring in adipocytes and ATMs and their reversibility by thiazolidinedione treatment. RESULTS: We show that polarization of ATMs is associated with lipid accumulation and the consequent formation of foam cell-like cells in adipose tissue. Our study reveals that early stages of adipose tissue expansion are characterized by M2-polarized ATMs and that progressive lipid accumulation within ATMs heralds the M1 polarization, a macrophage phenotype associated with severe obesity and insulin resistance. Furthermore, rosiglitazone treatment, which promotes redistribution of lipids toward adipocytes and extends the M2 ATM polarization state, prevents the lipid alterations associated with M1 ATM polarization. CONCLUSIONS: Our data indicate that the M1 ATM polarization in obesity might be a macrophage-specific manifestation of a more general lipotoxic pathogenic mechanism. This indicates that strategies to optimize fat deposition and repartitioning toward adipocytes might improve insulin sensitivity by preventing ATM lipotoxicity and M1 polarization.


Subject(s)
Adipocytes/metabolism , Adipose Tissue/metabolism , Inflammation/metabolism , Lipid Metabolism/physiology , Macrophages/metabolism , Obesity/metabolism , Animals , Cell Fractionation , Cells, Cultured , Diet , Flow Cytometry , Gene Expression Profiling , Insulin Resistance/physiology , Mice , Mice, Obese , Oligonucleotide Array Sequence Analysis
20.
PLoS One ; 5(10): e13615, 2010 Oct 26.
Article in English | MEDLINE | ID: mdl-21049019

ABSTRACT

Blastomere fate and embryonic genome activation (EGA) during human embryonic development are unsolved areas of high scientific and clinical interest. Forty-nine blastomeres from 5- to 8-cell human embryos have been investigated following an efficient single-cell cDNA amplification protocol to provide a template for high-density microarray analysis. The previously described markers, characteristic of Inner Cell Mass (ICM) (n = 120), stemness (n = 190) and Trophectoderm (TE) (n = 45), were analyzed, and a housekeeping pattern of 46 genes was established. All the human blastomeres from the 5- to 8-cell stage embryo displayed a common gene expression pattern corresponding to ICM markers (e.g., DDX3, FOXD3, LEFTY1, MYC, NANOG, POU5F1), stemness (e.g., POU5F1, DNMT3B, GABRB3, SOX2, ZFP42, TERT), and TE markers (e.g., GATA6, EOMES, CDX2, LHCGR). The EGA profile was also investigated between the 5-6- and 8-cell stage embryos, and compared to the blastocyst stage. Known genes (n = 92) such as depleted maternal transcripts (e.g., CCNA1, CCNB1, DPPA2) and embryo-specific activation (e.g., POU5F1, CDH1, DPPA4), as well as novel genes, were confirmed. In summary, the global single-cell cDNA amplification microarray analysis of the 5- to 8-cell stage human embryos reveals that blastomere fate is not committed to ICM or TE. Finally, new EGA features in human embryogenesis are presented.


Subject(s)
Blastomeres/metabolism , DNA, Complementary/genetics , Genomics , Gene Expression Profiling , Humans , Oligonucleotide Array Sequence Analysis
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