Efficient expression of the vascular endothelial growth factor gene in vitro and in vivo, using an adeno-associated virus vector

Vascular endothelial growth factor (VEGF) has proven to be one of the most effective growth factors for therapeutic angiogenesis. The biological effic acy of the adeno-associated virus (AAV) vector has recently been demonstrat ed in muscle tissues, including the heart. Apart from these promising insig hts into VEGF and the AAV vector, studies on WEGF gene transfer using the A AV vector have been limited, Here, we evaluate AAV-mediated VEGF gene trans fer, both in vitro and in vivo, using the AAV-mVEGF vector that contains cD NA for murine VEGF(120) within an HCMV-driven expression cassette. Transien t transfection of AAV-mVEGF plasmid significantly increased mVEGF expressio n in 293T cells. The secreted VEGF in the conditioned medium had strong bio logical activity, as confirmed by the Miles' vascular permeability assay. T ransduction of 293T and HeLa cells with AAV-mVEGF stock of high titer, that is essentially adenovirus-free, showed significantly increased mVEGF expre ssion above that of AAV-eGFP-transduced cells. When human umbilical vein en dothelial cells were transduced, a higher level of mVEGF expression, togeth er with higher cell counts, was observed compared to AAV-eGFP-transduced ce lls. In vivo transduction of mouse tibialis anterior muscle resulted in an increased level of mVEGF expression, and higher capillary-to-myofibre ratio , 8 weeks post-transduction. In a rat hindlimb ischemia model, regional blo od flow, as well as the capillary-to-myofibre ratio, was significantly incr eased at 4 weeks post-transduction. These findings demonstrate the efficien t delivery of the VEGF gene using an AAV vector, which has implications for angiogenic gene therapy in ischemic diseases, (C) 2001 Academic Press.