title: Spatiotemporal control of vascular endothelial growth factor expression using a heat-shock-activated, rapamycin-dependent gene switch.
abstract: A major challenge in regenerative medicine is to develop methods for delivering growth and differentiation factors in specific spatial and temporal patterns, thereby mimicking the natural processes of development and tissue repair. Heat shock (HS)-inducible gene expression systems can respond to spatial information provided by localized heating, but are by themselves incapable of sustained expression. Conversely, gene switches activated by small molecules provide tight temporal control and sustained expression, but lack mechanisms for spatial targeting. Here we combine the advantages of HS and ligand-activated systems by developing a novel rapamycin-regulated, HS-inducible gene switch that provides spatial and temporal control and sustained expression of transgenes such as firefly luciferase and vascular endothelial growth factor (VEGF). This gene circuit exhibits very low background in the uninduced state and can be repeatedly activated up to 1 month. Furthermore, dual regulation of VEGF induction in vivo is shown to stimulate localized vascularization, thereby providing a route for temporal and spatial control of angiogenesis.
authors.affiliation: Hospital Universitario La Paz-IdiPAZ, Madrid 28046, Spain.
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Martín-Saavedra
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Wilson
authors.forename: Richard
authors.initials: R
authors.lastname: Voellmy
authors.forename: Nuria
authors.initials: N
authors.lastname: Vilaboa
authors.forename: Renny T
authors.initials: RT
authors.lastname: Franceschi
mesh_terms: D000818:Animals; D002460:Cell Line; D005812:Genes, Switch; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D018869:Heat-Shock Response / Q000187:drug effects; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D051379:Mice; D008809:Mice, Inbred C3H; D009389:Neovascularization, Pathologic; D011401:Promoter Regions, Genetic; D020123:Sirolimus / Q000494:pharmacology*; D013696:Temperature; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*
chemical_list: D018840:HSP70 Heat-Shock Proteins; D042461:Vascular Endothelial Growth Factor A; D020123:Sirolimus