1. ¹Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
2. ²Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
3. ³Sangamo BioSciences, Point Richmond Tech Center II, Richmond, California, USA
4. ⁴Division of Molecular Therapy, Institute of Ophthalmology, University College London, London, UK

Correspondence: Peter A. Campochiaro, Maumenee 719, The Johns Hopkins University School of Medicine, 600 N. Wolfe Street, Baltimore, Maryland 21287-9277, USA. E-mail: pcampo@jhmi.edu

The first three authors contributed equally to this work.

Received 9 April 2007; Accepted 13 July 2007; Published online 14 August 2007.

Abstract

Zinc finger protein transcription factors (ZFP TFs) have been shown to positively or negatively regulate the expression of endogenous genes involved in a number of different disease processes. In this study we investigated whether gene transfer of an engineered ZFP TF designed to up-regulate expression of the chromosomal pigment epithelium-derived factor (Pedf) gene could suppress experimentally induced choroidal neovascularization (CNV). Transient transfection with engineered ZFP TFs significantly increased both Pedf messenger RNA (mRNA) and secreted PEDF protein levels in cell culture. Six weeks after intravitreous or subretinal injection of an adeno-associated viral (AAV) vector expressing the PEDF-activating ZFP TF in mice, we observed increased retinal Pedf mRNA, and a significant reduction in the size of CNV at Bruch's membrane rupture sites, assessed in vivo by fluorescein angiography or by postmortem measurements on choroidal flat mounts. Importantly, the anti-angiogenic activity persisted at 3 months after intravitreous injection. These data suggest that ZFP TF-driven enhancement of the endogenous anti-angiogenic defense system may provide a new approach for prophylaxis and treatment of neovascular diseases of the eye.