Systemic soluble Tie2 receptor expression inhibtis and regresses corneal neovascularization

Abstract

Abstract: : Purpose: To determine if soluble Tie2 receptor expression inhibits and regresses corneal neovascularization Methods: Corneas of BALB/c mice were scraped and BALB/c mice were injected with adenovirus expressing soluble Tie2 receptors, in tail vein . One group received adenovirus expressing soluble Tie2 receptors at the same time of corneal injury (0 week), while the other group were administered adenovirus 4 weeks after corneal scrape. Corneas were harvested after 2 weeks of adenovirus administeration and neovascularization was quantified by immunostaining, using FITC labeled anti–mouse monoclonal antibody CD31. VEGF levels of corneas were dected by ELISA( R&D Systems). RNA was also isolated from corneas and RT PCR was done to detect FAS , FASL and SDF levels. Results: The mean precentage of neovascularized corneal area in (0 week) treated mice were 57% as compared to 88% in the untreated ones. while in week 4 mice it was 44% in Tie2 administered mice as compared to 75% in controls. The VEGF levels were 185pg/ml in treated mice as compared to 50pg/ml in controls in (0 week) mice. while VEGF levels in (4 week ) mice were 46pg/ml in treated mice as compared to 35pg/ml in controls. No FAS and FASL were found in (0 week) treated or untreated mice while FAS and FASL were present in (4 week) treated mice as compared to the controls which were negative for both FAS and FASL . SDF was found to be positive in (0 week) and (4 week) mice. SDF was present in week 0 mice in both controls and treated mice but only in treated mice at week 4. Conclusions: sTie2 R inhibits and regresses corneal neovascularization in VEGF independent manner. The regressive effect may be related to mechanisms involving Fas –FasL interactions or SDF.

Keywords: cornea: endothelium • cornea: basic science