title: Identification of HIF-2α-regulated genes that play a role in human microvascular endothelial sprouting during prolonged hypoxia in vitro.
abstract: During prolonged hypoxic conditions, endothelial cells change their gene expression to adjust to the low oxygen environment. This process is mainly regulated by the hypoxia-inducible factors, HIF-1α and HIF-2α. Although endothelial cells do not form sprouts during prolonged hypoxic culturing, silencing of HIF-2α partially restores sprout formation. The present study identifies novel HIF-2α-target genes that may regulate endothelial sprouting during prolonged hypoxia. The gene expression profile of primary human microvascular endothelial cells (hMVECs) that were cultured at 20 % oxygen was compared to hMVECs that were cultured at 1 % oxygen for 14 days by using genome-wide RNA-sequencing. The differentially regulated genes in hypoxia were compared to the genes that were differentially regulated upon silencing of HIF-2α in hypoxia. Surprisingly, KEGG pathway analysis showed that metabolic pathways were enriched within genes upregulated in response to hypoxia and enriched within genes downregulated upon HIF-2α silencing. Moreover, 51 HIF-2α-regulated genes were screened for their role in endothelial sprouting in hypoxia, of which four genes ARRDC3, MME, PPARG and RALGPS2 directly influenced endothelial sprouting during prolonged hypoxic culturing. The manipulation of specific downstream targets of HIF-2α provides a new, but to be further evaluated, perspective for restoring reduced neovascularization in several pathological conditions, such as diabetic ulcers or other chronic wounds, for improvement of vascularization of implanted tissue-engineered scaffolds.
authors.affiliation: Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, De Boelelaan 1118, Room 11W53, 1081 HV, Amsterdam, The Netherlands.|A-Skin Nederland BV, De Boelelaan 1117, 1007 MB, Amsterdam, The Netherlands.
authors.forename: Tessa D
authors.initials: TD
authors.lastname: Nauta
authors.affiliation: Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, De Boelelaan 1118, Room 11W53, 1081 HV, Amsterdam, The Netherlands.|A-Skin Nederland BV, De Boelelaan 1117, 1007 MB, Amsterdam, The Netherlands.
authors.forename: Marloes
authors.initials: M
authors.lastname: van den Broek
authors.affiliation: Department of Dermatology, VU University Medical Center, Amsterdam, The Netherlands.|Departments of Oral Cell Biology and Dental Material Sciences, Academic Center for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit, Amsterdam, The Netherlands.
authors.forename: Sue
authors.initials: S
authors.lastname: Gibbs
authors.affiliation: Department of Molecular Cell Biology and Immunology, Institute for Cardiovascular Research, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Tineke C T M
authors.initials: TC
authors.lastname: van der Pouw-Kraan
authors.affiliation: Department of Clinical Chemistry, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Cees B
authors.initials: CB
authors.lastname: Oudejans
authors.affiliation: Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, De Boelelaan 1118, Room 11W53, 1081 HV, Amsterdam, The Netherlands.
authors.forename: Victor W M
authors.initials: VW
authors.lastname: van Hinsbergh
authors.affiliation: Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, De Boelelaan 1118, Room 11W53, 1081 HV, Amsterdam, The Netherlands. p.koolwijk@vumc.nl.
authors.forename: Pieter
authors.initials: P
authors.lastname: Koolwijk
mesh_terms: D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D002453:Cell Cycle / Q000187:drug effects / Q000235:genetics; D015687:Cell Hypoxia / Q000187:drug effects / Q000235:genetics; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D020868:Gene Silencing / Q000187:drug effects; D006801:Humans; D055806:Microvessels / Q000166:cytology*; D018919:Neovascularization, Physiologic / Q000235:genetics*; D010100:Oxygen / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D014162:Transfection; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D010100:Oxygen; D012333:RNA, Messenger; D000099162:Endothelial PAS Domain-Containing Protein 1
keywords: Angiogenesis; Genome-wide RNA-sequencing; HIF-2α; Hypoxia