title: HIV-1-mediated delivery of a short hairpin RNA targeting vascular endothelial growth factor in human retinal pigment epithelium cells.
abstract: BACKGROUND
  Vascular endothelial growth factor (VEGF) has been shown to play a major role in the pathological neovascularisation that occurs in degenerative retinal diseases like age-related macular degeneration (AMD). Although several approaches to attenuate VEGF show significant promise, repeated treatments are required to achieve therapeutic benefits. As lentiviruses efficiently and stably infect resting cells, a human immunodeficiency virus type 1 (HIV-1)-based vector was used for the delivery and long-term endogenous expression of a short hairpin RNA (shRNA) specific for VEGF in postmitotic human retinal pigment epithelium (RPE) cells.
  
  
  METHODS
  An HIV-1 vector expressing a shRNA targeting VEGF was developed and adopted to transduce RPE cell cultures, in both normoxic and hypoxic conditions in vitro. Intracellular VEGF expression was analysed by western blotting, and the release of VEGF in culture supernatants was determined by ELISA.
  
  
  RESULTS
  At least 90% of RPE cells were successfully transduced by HIV-1 virions. Inhibition of VEGF expression and reduction by 95% of VEGF release in transduced cells were achieved. Moreover, shRNA-VEGF effectively and specifically prevented hypoxia-induced VEGF upregulation.
  
  
  CONCLUSIONS
  HIV-1-mediated delivery of a shRNA-VEGF leading to gene expression knockdown could represent a novel therapeutic strategy against neovascularisation-related eye diseases.
authors.affiliation: Department of Biology, University of Padua, Viale G. Colombo 3, Padua, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Lombardi
authors.forename: A
authors.initials: A
authors.lastname: Calistri
authors.forename: M
authors.initials: M
authors.lastname: Curtarello
authors.forename: G L
authors.initials: GL
authors.lastname: Giudice
authors.forename: S
authors.initials: S
authors.lastname: Piermarocchi
authors.forename: G
authors.initials: G
authors.lastname: Prosdocimo
authors.forename: G
authors.initials: G
authors.lastname: Palù
authors.forename: C
authors.initials: C
authors.lastname: Parolin
mesh_terms: D002478:Cells, Cultured; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D055785:Gene Knockdown Techniques / Q000379:methods*; D020868:Gene Silencing; D005822:Genetic Vectors; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D055029:Inverted Repeat Sequences / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D055213:Retinal Pigment Epithelium / Q000166:cytology / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*
chemical_list: D034741:RNA, Small Interfering; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A