DisBa-01 Inhibits Angiogenesis, Inflammation and Fibrogenesis of Sponge-induced-fibrovascular Tissue in Mice

Integrins are involved in a number of physio-pathological processes including wound healing, chronic inflammation and neoplasias. Blocking its activity is potentially of therapeutic value in these conditions. We investigated whether DisBa-01, a recombinant His-tag RGD-disintegrin from Bothrops alternatus snake venom, could modulate key events (inflammatory cell recruitment/activation, neovascularization and extracellular matrix deposition) of the proliferative fibrovascular tissue induced by polyether polyurethane sponge implants in mice. The hemoglobin content (μg/mg wet tissue), blood flow measurements (laser Doppler perfusion imaging) and number of vessels in the implants, used as indices of vascularization, showed that the disintegrin dose-dependently reduced angiogenesis in the implants relative to the Saline-treated group. DisBa-01 inhibited neutrophil and macrophage content as determined by the myeloperoxidase (MPO) and N-acetyl-β-D-glucosaminidase (NAG) activities, respectively. Similarly, down regulation of the fibrogenic component studied (collagen deposition) was observed in DisBa-01-treated implants. VEGF, bFGF, TNF-α, CXCL1 and CCL2 levels were also decreased by the disintegrin. The inhibitory effect of this αvβ3-blocking disintegrin on the angiogenic, inflammatory, and fibrogenic components of the fibrovascular tissue induced by the synthetic matrix extends the range of DisBa-01 actions and may indicate its therapeutic potential in controlling angiogenesis in fibroproliferative diseases.