Antiangiogenic effects of bisphosphonates on laser-induced choroidal neovascularization in mice.

PURPOSE To demonstrate that bisphosphonates inhibit laser-induced choroidal neovascularization (CNV) in vivo and downregulate angiogenic gene expression in retinal pigment epithelial cells in vitro. METHODS Male C57BL/6 mice were treated with intraperitoneal injections of alendronate, clodronate, or saline at the onset (day 0) of experiments. CNV was induced by laser photocoagulation the next day, and fluorescein angiography (FA) was performed on experimental days 7 and 14. Histologic and immunohistochemical examinations were performed on day 7. ARPE-19 cells were grown on multi-plate wells coated with type I collagen to induce the gene expression of VEGF and integrins. Alendronate or clodronate was applied for 3 days, and real-time PCR was performed to measure VEGF-A, VEGF-B, and VEGF-C and integrin-alphaV, integrin-beta1, and integrin-beta3. RESULTS Alendronate and clodronate significantly suppressed the size of laser-induced CNV. Immunoreactivities for VEGF and integrin-alphaV were remarkably attenuated with alendronate and mildly reduced with clodronate. Alendronate significantly downregulated the gene expression profiles of VEGF and integrins, whereas clodronate had no effect in ARPE-19 cells. CONCLUSIONS Although only adverse effects of bisphosphonate have been documented in the ophthalmologic literature, some therapeutic effects of bisphosphonates, including antiangiogenesis, may be expected in ocular diseases. Antiangiogenic mechanisms of bisphosphonates may vary; further investigation is needed.