Inhibitory effect of canstatin in alkali burn-induced corneal neovascularization.

OBJECTIVE

To examine the effect of recombinant canstatin protein on the corneal neovascularization (CorNV) in an alkaline burn-induced CorNV model.

METHODS

This study involved 50 C57BL/6 mice. CorNV was induced by an alkaline burn of the corneas with 1 N NaOH under general anesthesia. Beginning 24 h after CorNV induction, recombinant canstatin protein was administered intraperitoneally at 5 or 10 mg/kg body weight once a day for up to 14 days. CorNV was evaluated by slit-lamp microscopy. Growth factors and cytokines relating to neovascularization and inflammation in the corneas were evaluated by real-time polymerase chain reaction (RT-PCR), Western blotting, immunohistochemistry or ELISA.

RESULTS

Recombinant canstatin protein significantly inhibited CorNV. Compared to the untreated or PBS-treated CorNV group, expression of vascular endothelial growth factor (VEGF) markedly decreased in the canstatin-treated group as detected by various methods. Western blotting and RT-PCR showed that the canstatin treatment inhibited the expression of hypoxia-inducible factor and VEGF. Day 7 revealed the greatest changes: ELISA assay showed that TNF-α also significantly decreased in canstatin-treated corneas.

CONCLUSIONS

Recombinant canstatin protein suppressed experimental CorNV, suggesting that canstatin may serve as a useful angiogenic inhibitor for the treatment of neovascularization-related corneal diseases.