title: Embryonic stem cells utilize reactive oxygen species as transducers of mechanical strain-induced cardiovascular differentiation.
abstract: Growing stem cells are subjected to mechanical forces, which may initiate differentiation programs. Mechanical strain stimulated cardiovascular differentiation of mouse embryonic stem (ES) cells as evaluated by quantification of contracting cardiac foci and capillary areas, respectively. Mechanical strain rapidly elevated intracellular reactive oxygen species (ROS). After 24 h up-regulation of NADPH oxidase subunits p22-phox, p47-phox, p67-phox, and Nox-4 as well as Nox-1 and Nox-4 mRNA was observed. In parallel, mechanical strain increased hypoxia-inducible factor-1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) mRNA and protein as well as MEF2C and GATA-4 mRNA, which are involved in cardiovascular development. Furthermore, phosphorylation of extracellular-regulated kinase 1,2 (ERK1,2), p38, and c-jun N-terminal kinase (c-Jun NH2-terminal kinase (JNK)) was observed. Stimulation of cardiovascular commitment, HIF-1alpha, VEGF, and MEF2C expression as well as MAPK activation were abolished by free radical scavengers, whereas GATA-4 expression was increased. Cardiomyogenesis was inhibited by the p38 inhibitor SB203580, the ERK1,2 inhibitor UO126, and the JNK inhibitor SP600125. Vasculogenesis/angiogenesis was blunted following inhibition of ERK1,2 and JNK, whereas p38 inhibition was ineffective. Our data outline a role of ROS as mechanotransducing molecules in mechanical strain-stimulated cardiovascular differentiation of ES cells, and point toward a microenvironment of elevated ROS required for signaling cascades initiating cardiovascular differentiation programs.
authors.affiliation: Department of Physiology Justus-Liebig-University Giessen, Aulweg 129 Giessen 35392, Germany.
authors.forename: Maike
authors.initials: M
authors.lastname: Schmelter
authors.forename: Bernadette
authors.initials: B
authors.lastname: Ateghang
authors.forename: Simone
authors.initials: S
authors.lastname: Helmig
authors.forename: Maria
authors.initials: M
authors.lastname: Wartenberg
authors.forename: Heinrich
authors.initials: H
authors.lastname: Sauer
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D004622:Embryo, Mammalian / Q000166:cytology*; D016166:Free Radical Scavengers / Q000494:pharmacology; D050991:GATA4 Transcription Factor / Q000378:metabolism; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism; D064326:MEF2 Transcription Factors; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000378:metabolism; D018006:Myogenic Regulatory Factors / Q000378:metabolism; D019255:NADPH Oxidases / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013234:Stem Cells / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D013314:Stress, Mechanical; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D016166:Free Radical Scavengers; D050991:GATA4 Transcription Factor; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D064326:MEF2 Transcription Factors; C578041:Mef2c protein, mouse; D018006:Myogenic Regulatory Factors; D017382:Reactive Oxygen Species; D042461:Vascular Endothelial Growth Factor A; D019255:NADPH Oxidases; D020928:Mitogen-Activated Protein Kinases