Abstract
Abstract: :
Purpose: This study investigated whether recombinant adenoassociated virus (rAAV) mediated overexpression of VEGF in the retina is sufficient to induce a neovascular response in the mouse eye. Methods: A recombinant adenoassociated virus vector expressing the mouse VEGF164 cDNA and green fluorescent protein (GFP) (rAAV.GFP.VEGF), under the control of separate human cytomegalovirus promoters was constructed and injected into the subretinal space of C57Bl/6J mice. The expression of the transgenes was monitored by fluorescence photography and fluorescence microscopy. Retinal neovascularization was followed using fluorescein angiography, histology and immunohistochemistry. Results: Following subretinal injection, the presence of a localized retinal detachment (bleb) involving approximately 20%-30% of the retina was confirmed by colour fundus photography. The GFP signal was detected in 100% of injected eyes as early as two weeks post-injection. A neovascular response in the retinal blood vessels was detected as a microvascular hyperpermeability of existing and/or newly formed blood vessels. Immunohistochemistry of whole mounted eyes demonstrated VEGF expression in the rAAV.GFP.VEGF injected and positive control eyes, but not in the non-injected and AAV.CMV.GFP injected eyes. Conclusion: These results demonstrated that overexpression of VEGF is sufficient to induce a limited neovascular response in the mouse eye suggesting that is an appropriate target for anti-angiogenic therapy.
Keywords: 483 neovascularization • 423 growth factors/growth factor receptors • 417 gene/expression