VEGF regulates FGF-2 and TGF-β1 expression in injury endothelial cells and mediates smooth muscle cells proliferation and migration

Abstract

Background Vascular endothelial growth factor (VEGF) is implicated in the development of restenosis after percutaneous transluminal coronary angioplasty (PTCA) as well as atherosclerosis. The purpose of our study was: 1) to evaluate the expression of endothelial cell (EC) fibroblast growth factor 2 (FGF-2) and transforming growth factor β1 (TGF-β1) mRNA expression following vascular injury and VEGF modulation and 2) to assess whether VEGF indirectly stimulates smooth muscle cell (SMC) migration and proliferation via growth factors released by injured EC. Methods Bovine aortic endothelial cells (BAEC) were cultured to near confluency and were serum starved. Linear wounds were made in medium with and without VEGF. FGF-2 and TGF-β1 mRNA expression were evaluated. Bovine aortic organ culture experiments were also carried out and growth factor expression was assessed. SMC proliferation and migration was assessed in response to EC injury medium with/without VEGF. Results EC injury in the presence of VEGF increased FGF-2 mRNA. EC injury also induced TGF-β1 mRNA expression; however VEGF inhibited TGF-β1 mRNA expression in both injured and noninjured ECs. VEGF increased FGF-2 mRNA stability and did not alter TGF-β1 mRNA stability. SMC proliferation and migration was found to be induced by injured EC media and injury EC medium with VEGF, respectively Conclusions The results demonstrate that 1) VEGF indirectly stimulates SMC proliferation and migration through stimulation of the expression of FGF-2 and 2) VEGF inhibits the expression of TGF-β1 released by EC. Theses data further suggest an integral role for FGF-2 and TGF-β1 in wound repair.