title: Constitutive expression of HIF-1alpha and HIF-2alpha in bone marrow stromal cells differentially promotes their proangiogenic properties.
abstract: Bone marrow stromal cells (BMSCs) contain progenitors capable of participating in postnatal angiogenesis. Hypoxia-inducible factors (HIFs) mediate endothelial activation by driving the expression of multiple angiogenic factors. We explored the potential of HIF-1alpha and HIF-2alpha modification in BMSCs, as a tool to improve cell-based angiogenic therapy. BMSCs were retrovirally transduced to express stable forms of HIF-1alpha and HIF-2alpha. HIF-1alpha and, to a greater extent, HIF-2alpha overexpression promoted differentiation of BMSCs to the endothelial lineage, evident by CD31 and Tie-2 expression and improved adhesive properties. Whereas chemotaxis toward stromal-derived factor 1 was higher in both HIF-alpha-expressing BMSCs, enhanced migration toward vascular endothelial growth factor was found only following overexpression of HIF-2alpha, supported by a robust expression of its receptor, Flk-1. HIF-alpha expression was associated with upregulation of angiogenic proteins and improved tube formation. Cytokine arrays of endothelial cells stimulated by medium collected from HIF-alpha-expressing BMSCs revealed further angiogenic activation and improved adhesive capacity. Eventually, delivery of HIF-2alpha-transduced BMSCs induced a more robust angiogenic response, compared with sham-transduced or HIF-1alpha-transduced BMSCs in the corneal micropocket angiogenesis model. Our results support the use of HIF-alpha genes, particularly HIF-2alpha, to augment the efficacy of future cell-based therapy. Disclosure of potential conflicts of interest is found at the end of this article.
authors.affiliation: Department of Cardiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Ben-Shoshan
authors.forename: Shulamit
authors.initials: S
authors.lastname: Schwartz
authors.forename: Galia
authors.initials: G
authors.lastname: Luboshits
authors.forename: Sofia
authors.initials: S
authors.lastname: Maysel-Auslender
authors.forename: Aya
authors.initials: A
authors.lastname: Barzelay
authors.forename: Sylvie
authors.initials: S
authors.lastname: Polak-Charcon
authors.forename: Eldad
authors.initials: E
authors.lastname: Tzahor
authors.forename: Iris
authors.initials: I
authors.lastname: Barshack
authors.forename: Adiel
authors.initials: A
authors.lastname: Barak
authors.forename: Hani
authors.initials: H
authors.lastname: Levkovitch-Verbin
authors.forename: Gad
authors.initials: G
authors.lastname: Keren
authors.forename: Jacob
authors.initials: J
authors.lastname: George
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000378:metabolism*; D001854:Bone Marrow Cells / Q000166:cytology* / Q000201:enzymology; D002448:Cell Adhesion; D002454:Cell Differentiation; D002465:Cell Movement; D002478:Cells, Cultured; D054377:Chemokine CXCL12 / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism*; D008297:Male; D051379:Mice; D018919:Neovascularization, Physiologic; D019899:Paracrine Communication; D051381:Rats; D017208:Rats, Wistar; D019718:Receptors, CXCR4 / Q000378:metabolism; D012190:Retroviridae; D017154:Stromal Cells / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*; D014161:Transduction, Genetic; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D054377:Chemokine CXCL12; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D019718:Receptors, CXCR4; D042461:Vascular Endothelial Growth Factor A; D040301:Vascular Endothelial Growth Factor Receptor-2; D000099162:Endothelial PAS Domain-Containing Protein 1; C486264:Cxcr4 protein, rat