Subconjunctival gene delivery of the transcription factor GA-binding protein delays corneal neovascularization in a mouse model

Abstract

Corneal neovascularization can reduce visual acuity. GAbinding protein (GABP) is a transcription factor that regulates the expression of target genes including vascular endothelial growth factor (VEGF) and roundabout4 (Robo4), which participate in pathologic angiogenesis. We assessed whether intraocular injection of the GABP gene affects the growth of new corneal blood vessels in a mouse ocular neovascularization model. Transfection of human GABPa and GABPb gene (GABPa/b) into human conjunctival epithelial cells resulted in decreased VEGF and Robo4 expression. Three groups of mice underwent chemical and mechanical denudation of the corneal epithelium. Subsequently, two groups were administered subconjunctival injection of lipoplexes carrying plasmid DNA encoding for human GABPa/b or an empty plasmid DNA at 1-week intervals. The third group served as an experimental control. In vivo delivery of human GABPa/b into mouse neovascularized cornea reduced VEGF and Robo4 gene expression. Biomicroscopic examination showed that, at 1 week after one or two injections, GABPa/b-treated eyes had significantly less neovascularized corneal area than did eyes treated with the empty vector. Histologic examination showed significantly less vascularized area and fewer blood vessels in the GABP-treated group at 1 week after injections. However, these angiosuppressive effects were weakened at 2 weeks after injections. Our results indicate that subconjunctival GABP gene delivery delays corneal neovascularization for up to 2 weeks in a mouse model of deliberate corneal injury.

Activation of Endothelial Roundabout Receptor 4 Reduces the Severity of Virus-Induced Keratitis

“…In vivo experiments were done in HSV infected animals to determine if the lentiviral vector expressing Slit2 shRNAs had any effect on the extent of angiogenesis. The subconjunctival delivery (25) of lentiviruses encoding Slit2 shRNAs was started from day 1 post HSV infection with additional administrations on alternate days (fig 3C). Corneas collected at day 9 revealed diminished Slit2 mRNA and protein compared to controls (fig 3D&E) suggesting a reduction in Slit2 mRNA and protein in vivo after lentiviral Slit2 shRNA administrations.…”

Regulation of angiogenesis by ETS transcription factors

“…These studies suggest a homoeostatic role for GABP in promoting quiescence of the vascular wall. A recent report by Yoon et al [38] found that intraocular injection of the GABP gene delayed corneal neovascularization in a mouse model, providing the first direct evidence for a role of GABP in adult angiogenesis in vivo.…”

Gene therapy in the Cornea: 2005–present

“…Other gene transfer studies have assessed the utility of CD36 (Mwaikambo et al, 2006), pigment epithelium derived factor (Kuo et al, 2009), and GA binding protein (Yoon et al, 2009) among other approaches to treating CNV. Future experiments may include vector mediated delivery of inhibitors of angiogenesis derived from basement membrane such as neostatin, restin, arresten, canstatin, and tumstatin (Ellenberg et al, 2010).…”