Abstract
Purpose:
This study was designed to determine the role and underlying mechanisms of integrin α5β1 in angiogenesis in human choroidal endothelial cells (hCECs), and to evaluate the anti-angiogenic effects of combined therapy of ATN-161 (AC-PHSCN-NH2), an integrinα5β1 inhibitor, and anti-VEGF mAb in laser-induced CNV in experimental rats.
Methods:
The antiangiogenic potential of ATN-161 was evalu-ated in VEFG-stimulated hCECs by MTS proliferation assays,migration assays, and synthetic matrix capillary tube formation assays. To evaluate the antiangiogenic effects of ATN-161 in vivo, CNV was induced in rats by laser photocoagulation. ATN-161, AF564 anti-VEGF antibody, combined regeants were injected intravitreally immediately after photocoagula-tion. Eyes were examined by SD-OCT and fluorescein an-giography on days 1, 7, and 14 after injection, and the areas of CNV were measured by analysis of choroidal flatmounts at day 14. We
Results:
We demonstrated that fibronectin (Fn) bound to integrin α5β1 and induced angiogenesis by increasing hCECs migration, up-regulating VEGF expression, and stimulating CD147 activity. Integrin α5β1 regulated VEGF expression via two independent downstream signaling pathways, FN/integrin α5β1/FAK/ERK1/2 and FN/integrin α5β1/FAK/AKT, followed by induction of HIF1α, c-JUN and Sp1 binding. Treatment with ATN-161 plus anti-VEGF antibody attenuated angiogenesis more effectively than either agent alone.
Conclusions:
In summary, these results provide the first evidence for a role of Integrin α5β1 in ocular pathological neovascularization in vivo. The inhibition of Integrin α5β1 by ATN-161 may be a promising novel therapy for CNV.
Keywords: 453 choroid: neovascularization •
519 extracellular matrix