title: Small interfering RNA targeting PGC-1α inhibits VEGF expression and tube formation in human retinal vascular endothelial cells.
abstract: OBJECTIVE
  To determine whether small interfering RNA (siRNA) of PGC-1α could inhibit vascular endothelial growth factor (VEGF) expression and tube formation in human retinal vascular endothelial cells (hRVECs).
  
  
  METHODS
  hRVECs transfected with peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) siRNA were incubated for 24h and then placed into a normoxic (20%, O2) or hypoxic (1%, O2) environment for another 16h. PGC-1α mRNA and protein levels were detected by real-time PCR and Western blot. VEGF mRNA and protein levels were detected by real-time PCR and ELISA. Cell proliferation was evaluated by BrdU incorporation assay. Forty-eight hours after siRNA transfection, hRVECs were planted into Matrigel-coated plates and cultured under normoxic (20%, O2) or hypoxic (1%, O2) conditions for another 48h. The tube formation of hRVECs was observed under an optical microscope and quantified by counting the number of branch points and calculating the total tube length.
  
  
  RESULTS
  PGC-1α mRNA and protein levels were significantly reduced by PGC-1α siRNA, and VEGF mRNA and protein levels also decreased significantly. The percentage of BrdU-labeled cells in siPGC-1α groups were significantly decreased compared with control siRNA groups under normoxia and hypoxia in cell proliferation assay. In the tube formation assay, PGC-1α siRNA treated cells formed significantly fewer tubes.
  
  
  CONCLUSIONS
  Blocking PGC-1α expression can inhibit VEGF expression in hRVECs and inhibit their ability to form tubes under both normoxic and hypoxic conditions.
authors.affiliation: Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Jiang
authors.affiliation: Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China.
authors.forename: Xiao-Bo
authors.initials: XB
authors.lastname: Xia
keywords: peroxisome proliferator-activated receptor-γ coactivator-1α; retinal vascular endothelial cell; small interfering RNA; tube formation; vascular endothelial growth factor