TIMP-1 DNA reduces VEGF-induced angiogenesis by inhibition of MMP-9 activity. Groups of mice were treated intraocularly with TIMP-1 DNA or vector DNA, and hydron pellets containing rh VEGF (90 ng) were implanted into the corneal pellets. At day 4 after treatment, animals were sacrificed, and corneas were excised and pooled from eight eyes and homogenized. The concentrations of protein were measured by the Bradford method. Corneal extract samples (20 μg/lane) were analyzed by gelatin zymography. Similar results were obtained in three independent experiments. Lane 1: corneal sample from TIMP-1 DNA–treated group; lane 2: corneal sample from vector DNA–treated group.