Neutrophil elastase cleaves VEGF to generate a VEGF fragment with altered activity

Vascular Endothelial Growth Factor (VEGF) and neutrophil elastase (NE) are implicated in the progression of emphysema. We investigated the potential connection between VEGF and NE injury. 125 I‐VEGF was treated with NE, and the product visualized by SDS‐PAGE. We found that NE cleaves VEGF 165 to a ∼34kDa disulfide linked fragment. VEGF interacts with cell surface receptors and components of the extracellular matrix, such as fibronectin and heparan sulfate. Hence, we examined the binding of the NE generated VEGF fragment (VEGFf) to VEGFR(1 and 2)‐Fc constructs, and found that VEGFf retained the ability to bind VEGFR1 but lost the ability to bind VEGFR2. We also examined VEGFf binding to fibronectin ± heparin and found that, unlike intact VEGF 165 , VEGFf did not bind fibronectin. VEGFf bound heparin, albeit with a reduced affinity compared to intact VEGF 165 . We assessed the activity of VEGFf in endothelial cells, and found that it did not activate ERK1/2 alone yet it enhanced VEGF 165 activation of ERK1/2. We performed migration assays using macrophage RAW264.7 cells that express VEGFR1, and found that VEGFf and VEGF stimulated migration to a similar extent. VEGFf also activated Akt in endothelial and RAW264.7 cells. Our data indicate that NE generated VEGFf has altered activity, which might lead to functional changes within the injured lung. Supported by HL56200 and HL46920.