title: Matrix metalloproteinase-9 and vascular endothelial growth factor expression change in experimental retinal neovascularization.
abstract: OBJECTIVE
  To investigate the signal transduction mechanism of matrix metalloproteinase-9 (MMP-9) mediated- vascular endothelial growth factor (VEGF) expression and retinal neovascularization (RNV) in oxygen-induced retinopathy (OIR) model.
  
  
  METHODS
  C57BL/6J mice were divided into four groups: control group, OIR group, OIR control group (phosphate-buffered saline by intravitreal injection) and treated group [tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) by intravitreal injection]. OIR model was established in C57BL/6J mice exposed to 75%±2% oxygen for 5d. mRNA level and protein expression of MMP-9, TIMP-1 and VEGF were measured by real-time polymerase chain reaction and Western blotting, and located by immunohistochemistry.
  
  
  RESULTS
  Levels of MMP-9 and VEGF in retina were significantly increased in animals with OIR and OIR control group. Levels of TIMP-1 in retina was significantly reduced in animals with OIR and OIR control group. Furthermore, a significant correlation was found between MMP-9 and VEGF. Intravitreal injection of TIMP-1 significantly reduced MMP-9 and VEGF expression of the OIR mouse model (all P<0.05).
  
  
  CONCLUSIONS
  These results demonstrate that MMP-9-mediated up-regulation of VEGF promotes RNV in retinopathy of prematurity (ROP). TIMP-1 may be a potential target for the prevention and treatment of ROP.
authors.affiliation: Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Di
authors.affiliation: Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China.
authors.forename: Qing-Zhu
authors.initials: QZ
authors.lastname: Nie
authors.affiliation: Department of Ophthalmology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China.
authors.forename: Xiao-Long
authors.initials: XL
authors.lastname: Chen
keywords: matrix metalloproteinase-9; oxygen-induced retinopathy; retinal neovascularization; vascular endothelial growth factor