In vivo angiogenesis induced by recombinant adenovirus vectors coding either for secreted or nonsecreted forms of acidic fibroblast growth factor

In vivo gene transfer of angiogenic growth factors represents a potential approach to the treatment of ischemic diseases. The present study examined the in vitro and in vivo effects of two replication-deficient recombinant adenovirus (Ad) vectors coding for human acidic fibroblast growth factor (aFGF_1-154). One vector codes for the nonsecreted form of the peptide (AdCMV.aFGF_1-154), and the other vector codes for a recombinant, secreted form (AdCMV.sp+aFGF_1-154). AdCMV.NLSβgal, an adenovirus vector coding for β-galactosidase (β-Gal), was used as a control. Assessment of proliferation of starved human umbilical vein endothelial cells infected with AdCMV.aFGF_1-154 and AdCMV.sp+aFGF_1-154 (20 pfu/cell) showed approximately 6- and 10-fold increase in cell number over control, respectively. Infection with AdCMV.sp+aFGF_1-154 and with AdCMV.aFGF_1-154 enhanced endothelial cell differentiation into capillary-like structures in vitro. However, this effect was significantly more pronounced with AdCMV.sp+aFGF_1-154 than with AdCMV.aFGF_1-154. Angiogenesis in vivo was assessed by injecting subcutaneously into mice 750 μl of reconstituted basement membrane proteins (Matrigel) and the Ad vectors (2 x 10⁸ pfu). After 14 days, there was histologic evidence of neovascularization in the animal's tissue surrounding the Matrigel plugs with AdCMV.aFGP_1-154 and AdCMV.sp+aFGF_1-154. Further, the hemoglobin content of the Matrigel plugs with AdCMV.aFGF_1-154 and with AdCMV.sp+aFGF_1-154 was, respectively, 2.3- and 2.6-fold higher than with AdCMV.NLSβgal. Together, these observations support the concept that adenovirus vectors coding for various forms of acidic FGF_1-154 may be used to induce angiogenesis in vivo and may provide a new therapeutic approach to ischemic diseases.