TY - JOUR T1 - Development, Characterization and Experimental Validation of a Cultivated Sunflower (Helianthus annuus L.) Gene Expression Oligonucleotide Microarray. JF - PloS one Y1 - 2012 A1 - Fernandez, Paula A1 - Soria, Marcelo A1 - Blesa, David A1 - Dirienzo, Julio A1 - Moschen, Sebastián A1 - Rivarola, Máximo A1 - Clavijo, Bernardo Jose A1 - Gonzalez, Sergio A1 - Peluffo, Lucila A1 - Príncipi, Dario A1 - Dosio, Guillermo A1 - Aguirrezabal, Luis A1 - Garcia-Garcia, Francisco A1 - Ana Conesa A1 - Hopp, Esteban A1 - Joaquín Dopazo A1 - Heinz, Ruth Amelia A1 - Paniego, Norma AB - Oligonucleotide-based microarrays with accurate gene coverage represent a key strategy for transcriptional studies in orphan species such as sunflower, H. annuus L., which lacks full genome sequences. The goal of this study was the development and functional annotation of a comprehensive sunflower unigene collection and the design and validation of a custom sunflower oligonucleotide-based microarray. A large scale EST (>130,000 ESTs) curation, assembly and sequence annotation was performed using Blast2GO (www.blast2go.de). The EST assembly comprises 41,013 putative transcripts (12,924 contigs and 28,089 singletons). The resulting Sunflower Unigen Resource (SUR version 1.0) was used to design an oligonucleotide-based Agilent microarray for cultivated sunflower. This microarray includes a total of 42,326 features: 1,417 Agilent controls, 74 control probes for sunflower replicated 10 times (740 controls) and 40,169 different non-control probes. Microarray performance was validated using a model experiment examining the induction of senescence by water deficit. Pre-processing and differential expression analysis of Agilent microarrays was performed using the Bioconductor limma package. The analyses based on p-values calculated by eBayes (p<0.01) allowed the detection of 558 differentially expressed genes between water stress and control conditions; from these, ten genes were further validated by qPCR. Over-represented ontologies were identified using FatiScan in the Babelomics suite. This work generated a curated and trustable sunflower unigene collection, and a custom, validated sunflower oligonucleotide-based microarray using Agilent technology. Both the curated unigene collection and the validated oligonucleotide microarray provide key resources for sunflower genome analysis, transcriptional studies, and molecular breeding for crop improvement. VL - 7 UR - http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0045899 ER - TY - JOUR T1 - Hypoxia promotes efficient differentiation of human embryonic stem cells to functional endothelium. JF - Stem Cells Y1 - 2010 A1 - Prado-Lopez, Sonia A1 - Conesa, Ana A1 - Armiñán, Ana A1 - Martínez-Losa, Magdalena A1 - Escobedo-Lucea, Carmen A1 - Gandia, Carolina A1 - Tarazona, Sonia A1 - Melguizo, Dario A1 - Blesa, David A1 - Montaner, David A1 - Sanz-González, Silvia A1 - Sepúlveda, Pilar A1 - Götz, Stefan A1 - O'Connor, José Enrique A1 - Moreno, Ruben A1 - Dopazo, Joaquin A1 - Burks, Deborah J A1 - Stojkovic, Miodrag KW - Angiopoietin-1 KW - Animals KW - biomarkers KW - Cell Culture Techniques KW - Cell Differentiation KW - Cell Hypoxia KW - Cell Transplantation KW - Cells, Cultured KW - Down-Regulation KW - Embryonic Stem Cells KW - Endothelial Cells KW - Gene Expression Profiling KW - Gene Expression Regulation KW - Humans KW - Male KW - Myocardial Infarction KW - Neovascularization, Physiologic KW - Oxygen KW - Pluripotent Stem Cells KW - Rats KW - Rats, Nude KW - Vascular Endothelial Growth Factor A AB -

Early development of mammalian embryos occurs in an environment of relative hypoxia. Nevertheless, human embryonic stem cells (hESC), which are derived from the inner cell mass of blastocyst, are routinely cultured under the same atmospheric conditions (21% O(2)) as somatic cells. We hypothesized that O(2) levels modulate gene expression and differentiation potential of hESC, and thus, we performed gene profiling of hESC maintained under normoxic or hypoxic (1% or 5% O(2)) conditions. Our analysis revealed that hypoxia downregulates expression of pluripotency markers in hESC but increases significantly the expression of genes associated with angio- and vasculogenesis including vascular endothelial growth factor and angiopoitein-like proteins. Consequently, we were able to efficiently differentiate hESC to functional endothelial cells (EC) by varying O(2) levels; after 24 hours at 5% O(2), more than 50% of cells were CD34+. Transplantation of resulting endothelial-like cells improved both systolic function and fractional shortening in a rodent model of myocardial infarction. Moreover, analysis of the infarcted zone revealed that transplanted EC reduced the area of fibrous scar tissue by 50%. Thus, use of hypoxic conditions to specify the endothelial lineage suggests a novel strategy for cellular therapies aimed at repair of damaged vasculature in pathologies such as cerebral ischemia and myocardial infarction.

VL - 28 IS - 3 U1 - https://www.ncbi.nlm.nih.gov/pubmed/20049902?dopt=Abstract ER -