title: Hypoxia promotes efficient differentiation of human embryonic stem cells to functional endothelium.
abstract: 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.
authors.affiliation: Cellular Reprogramming Laboratory, Avenida del Autopista del Saler 16, 46013 Valencia, Spain.
authors.forename: Sonia
authors.initials: S
authors.lastname: Prado-Lopez
authors.forename: Ana
authors.initials: A
authors.lastname: Conesa
authors.forename: Ana
authors.initials: A
authors.lastname: Armiñán
authors.forename: Magdalena
authors.initials: M
authors.lastname: Martínez-Losa
authors.forename: Carmen
authors.initials: C
authors.lastname: Escobedo-Lucea
authors.forename: Carolina
authors.initials: C
authors.lastname: Gandia
authors.forename: Sonia
authors.initials: S
authors.lastname: Tarazona
authors.forename: Dario
authors.initials: D
authors.lastname: Melguizo
authors.forename: David
authors.initials: D
authors.lastname: Blesa
authors.forename: David
authors.initials: D
authors.lastname: Montaner
authors.forename: Silvia
authors.initials: S
authors.lastname: Sanz-González
authors.forename: Pilar
authors.initials: P
authors.lastname: Sepúlveda
authors.forename: Stefan
authors.initials: S
authors.lastname: Götz
authors.forename: José Enrique
authors.initials: JE
authors.lastname: O'Connor
authors.forename: Rubén
authors.initials: R
authors.lastname: Moreno
authors.forename: Joaquín
authors.initials: J
authors.lastname: Dopazo
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Burks
authors.forename: Miodrag
authors.initials: M
authors.lastname: Stojkovic
mesh_terms: D042683:Angiopoietin-1 / Q000235:genetics; D000818:Animals; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000502:physiology*; D015687:Cell Hypoxia / Q000235:genetics; D017690:Cell Transplantation / Q000379:methods; D002478:Cells, Cultured; D015536:Down-Regulation / Q000235:genetics; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D020869:Gene Expression Profiling / Q000379:methods; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000601:surgery; D018919:Neovascularization, Physiologic / Q000235:genetics; D010100:Oxygen / Q000378:metabolism*; D039904:Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism; D051381:Rats; D011923:Rats, Nude; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics
chemical_list: D042683:Angiopoietin-1; D015415:Biomarkers; D042461:Vascular Endothelial Growth Factor A; C467498:vascular endothelial growth factor A, rat; D010100:Oxygen