title: Treatment of mouse limb ischemia with an integrative hypoxia-responsive vector expressing the vascular endothelial growth factor gene.
abstract: Constitutive vascular endothelial growth factor (VEGF) gene expression systems have been extensively used to treat peripheral arterial diseases, but most of the results have not been satisfactory. In this study, we designed a plasmid vector with a hypoxia-responsive element sequence incorporated into it with the phiC31 integrative system (pVHAVI) to allow long-term VEGF gene expression and to be activated under hypoxia. Repeated activations of VEGF gene expression under hypoxia were confirmed in HEK293 and C2C12 cells transfected with pVHAVI. In limb ischemic mice, the local administration of pVHAVI promoted gastrocnemius mass and force recovery and ameliorated limb necrosis much better than the group treated with hypoxia-insensitive vector, even this last group had produced more VEGF in muscle. Histological analyses carried out after four weeks of gene therapy showed increased capillary density and matured vessels, and reduced number of necrotic cells and fibrosis in pVHAVI treated group. By our study, we demonstrate that the presence of high concentration of VEGF in ischemic tissue is not beneficial or is less beneficial than maintaining a lower but sufficient and long-term concentration of VEGF locally.
authors.affiliation: Research Center for Gene Therapy, Department of Biophysics, Universidade Federal de São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Eduardo Gallatti
authors.initials: EG
authors.lastname: Yasumura
authors.forename: Roberta Sessa
authors.initials: RS
authors.lastname: Stilhano
authors.forename: Vívian Yochiko
authors.initials: VY
authors.lastname: Samoto
authors.forename: Priscila Keiko
authors.initials: PK
authors.lastname: Matsumoto
authors.forename: Leonardo Pinto
authors.initials: LP
authors.lastname: de Carvalho
authors.forename: Valderez Bastos
authors.initials: VB
authors.lastname: Valero Lapchik
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Han
mesh_terms: D000818:Animals; D002460:Cell Line; D004195:Disease Models, Animal; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics / Q000627:therapeutic use; D057809:HEK293 Cells; D006614:Hindlimb / Q000098:blood supply / Q000473:pathology; D006801:Humans; D000860:Hypoxia; D007511:Ischemia / Q000473:pathology / Q000628:therapy*; D051379:Mice; D014162:Transfection; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics* / Q000378:metabolism
chemical_list: D042461:Vascular Endothelial Growth Factor A