title: Mechanical strain stimulates vasculogenesis and expression of angiogenesis guidance molecules of embryonic stem cells through elevation of intracellular calcium, reactive oxygen species and nitric oxide generation.
abstract: Differentiation of embryonic stem (ES) cells may be regulated by mechanical strain. Herein, signaling molecules underlying mechanical stimulation of vasculogenesis and expression of angiogenesis guidance cues were investigated in ES cell-derived embryoid bodies.
  
  
  
  Treatment of embryoid bodies with 10% static mechanical strain using a Flexercell strain system significantly increased CD31-positive vascular structures and the angiogenesis guidance molecules plexinB1, ephrin B2, neuropilin1 (NRP1), semaphorin 4D (sem4D) and robo4 as well as vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2) and platelet-derived growth factor-BB (PDGF-BB) as evaluated by Western blot and real time RT-PCR. In contrast ephrin type 4 receptor B (EphB4) expression was down-regulated upon mechanical strain, indicating an arterial-type differentiation. Robo1 protein expression was modestly increased with no change in mRNA expression. Mechanical strain increased intracellular calcium as well as reactive oxygen species (ROS) and nitric oxide (NO). Mechanical strain-induced vasculogenesis was abolished by the NOS inhibitor L-NAME, the NADPH oxidase inhibitor VAS2870, upon chelation of intracellular calcium by BAPTA as well as upon siRNA inactivation of ephrin B2, NRP1 and robo4. BAPTA blunted the strain-induced expression of angiogenic growth factors, the increase in NO and ROS as well as the expression of NRP1, sem4D and plexinB1, whereas ephrin B2, EphB4 as well as robo1 and robo4 expression were not impaired.
  
  
  
  Mechanical strain stimulates vasculogenesis of ES cells by the intracellular messengers ROS, NO and calcium as well as by upregulation of angiogenesis guidance molecules and the angiogenic growth factors VEGF, FGF-2 and PDGF-BB.
authors.affiliation: Department of Physiology, Faculty of Medicine, Justus Liebig University Giessen, Germany.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Sharifpanah
authors.affiliation: Department of Physiology, Faculty of Medicine, Justus Liebig University Giessen, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Behr
authors.affiliation: Department of Internal Medicine, Cardiology Division, Friedrich Schiller University Jena, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Wartenberg
authors.affiliation: Department of Physiology, Faculty of Medicine, Justus Liebig University Giessen, Germany. Electronic address: heinrich.sauer@physiologie.med.uni-giessen.de.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Sauer
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D000077214:Becaplermin; D001583:Benzoxazoles / Q000494:pharmacology; D001696:Biomechanical Phenomena; D002118:Calcium / Q000819:agonists / Q000378:metabolism*; D002454:Cell Differentiation; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004622:Embryo, Mammalian; D058732:Embryoid Bodies / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D036388:Ephrin-B2 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation; D051379:Mice; D000066450:Mouse Embryonic Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000235:genetics; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D039942:Neuropilin-1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D009569:Nitric Oxide / Q000819:agonists / Q000378:metabolism*; D020574:Proto-Oncogene Proteins c-sis / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000819:agonists / Q000378:metabolism*; D036224:Receptor, EphB4 / Q000235:genetics / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D011971:Receptors, Immunologic / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D039961:Semaphorins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014230:Triazoles / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism
chemical_list: C511179:3-benzyl-7-(2-benzoxazolyl)thio-1,2,3-triazolo(4,5-d)pyrimidine; D015703:Antigens, CD; D001583:Benzoxazoles; C093224:CD100 antigen; D036388:Ephrin-B2; D009419:Nerve Tissue Proteins; C492118:Plxnb1 protein, mouse; D020574:Proto-Oncogene Proteins c-sis; D034741:RNA, Small Interfering; D017382:Reactive Oxygen Species; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; C540792:Robo4 protein, mouse; D039961:Semaphorins; D014230:Triazoles; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; D016222:Fibroblast Growth Factor 2; D039942:Neuropilin-1; D000077214:Becaplermin; D009569:Nitric Oxide; D004533:Egtazic Acid; C086681:Ephb4 protein, mouse; D036224:Receptor, EphB4; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium; D019331:NG-Nitroarginine Methyl Ester
keywords: Embryonic stem cells; Intracellular calcium; Mechanical strain; Nitric oxide; Reactive oxygen species; Vasculogenesis