Hepatocyte growth factor fusion protein having collagen-binding activity (CBD-HGF) accelerates re-enclothelialization and intimal hyperplasia in balloon-injured rat carotid artery

Aim: Hepatocyte growth factor (HGF) is known to stimulate endothelial cell proliferation. However, re-endothelialization is not enhanced when the native protein is administered to the injured artery, probably due to the short half-life of HGF at the site of injury. Therefore, the effects of an HGF fusion protein having collagen-binding activity (CBD-HGF) on re-endothelialization and neointimal formation was studied in the balloon-injured rat carotid artery. Methods: The left common carotid artery of male Sprague-Dawley rats was injured with an inflated balloon catheter, and then treated with CBD-HGF (10 mu g/mL), HGF (10 mu g/mL) or saline (control) for 15 min. After 14 days, the rats were injected with Evans blue and sacrificed. Results: The re-endothelialized area was significantly greater in the CBD-HGF treated rats than in the control or HGF treated rats. Neointimal formation was significantly more pronounced in the CBD-HGF treated rats than in other rat groups. Both HGF and CBD-HGF stimulated proliferation of vascular smooth muscle cells as well as endothelial cells in vitro. Consistent with this, cultured smooth muscle cells were shown to express the HGF receptor (c-Met). Conclusion: CBD-HGF accelerates re-endothelialization and neointimal formation in vivo. CBD fusion protein is a useful vehicle to deliver vascular growth factors to injured arteries.