Downregulation of IRS-1 Expression Causes Inhibition of Corneal Angiogenesis

• Published in: Investigative ophthalmology & visual science Vol. 46; no. 11; pp. 4072 - 4078
• Main Authors: Berdugo, Marianne, Andrieu-Soler, Charlotte, Doat, Marc, Courtois, Yves, BenEzra, David, Behar-Cohen, Francine
• Format: Journal Article
• Language: English
• Published: Rockville, MD ARVO 01.11.2005; Association for Research in Vision and Ophtalmology
• Subjects: Angiogenesis Inhibitors - therapeutic use; Animals; Biological and medical sciences; Blotting, Western; Conjunctiva - drug effects; Corneal Neovascularization - metabolism; Corneal Neovascularization - pathology; Corneal Neovascularization - prevention & control; Disease Models, Animal; Down-Regulation; Eye and associated structures. Visual pathways and centers. Vision; Fundamental and applied biological sciences. Psychology; Immunohistochemistry; Injections; Insulin Receptor Substrate Proteins; Interleukin-1 - genetics; Interleukin-1 - metabolism; Oligodeoxyribonucleotides, Antisense - therapeutic use; Phosphoproteins - genetics; Phosphoproteins - metabolism; Rats; Rats, Inbred Lew; RNA, Messenger - metabolism; Specific Pathogen-Free Organisms; Vascular Endothelial Growth Factor A - genetics; Vascular Endothelial Growth Factor A - metabolism; Vertebrates: nervous system and sense organs; Angiogenesis; Cornea; Inhibition; Ophthalmology
• ISSN: 0146-0404; 1552-5783; 1552-5783
• DOI: 10.1167/iovs.05-0105

The antiangiogenic effect of an antisense oligodeoxynucleotide (ODN) targeting insulin receptor substrate (IRS)-1 was evaluated on rat corneal neovascularization. Eyes with neovessels were treated with subconjunctival injections of IRS-1 antisense oligonucleotide (ASODN), IRS-1 sense ODN (SODN), or PBS. At 8 and 24 hours after the first subconjunctival injection, the expression of IRS-1, VEGF, and IL-1beta mRNA was evaluated. IRS-1 protein levels were also measured at 8 hours by Western blot analysis (n = 4/group). On day 10, corneal neovascularization was quantified in flatmount corneas of rats treated daily from days 4 to 9. On day 10, new vessels covered 95.5% +/- 4% of the corneal area in PBS-treated eyes, 92% +/- 7% in SODN-treated eyes and 59% +/- 20% in ASODN-treated eyes (P < 0.001). In the ASODN-treated group, the expression and synthesis of IRS-1 were significantly downregulated when compared with the control groups. ASODN did not significantly affect the expression of VEGF but significantly decreased the expression of IL-1beta at 24 hours (P = 0.04). Subconjunctival injections of IRS-1 antisense ODN significantly inhibit rat corneal neovascularization. This effect may be mediated by a downregulation of IL-1beta. IRS-1 proteins may be interesting targets for the regulation of angiogenesis mediated by insulin, hypoxia, or inflammation.