Timing and Targeting of Cell-Based VEGF165 Gene Expression in Ischemic Tissue

Vascular Endothelial Growth Factor (VEGF165) Plus Basic Fibroblast Growth Factor (bFGF) Producing Cells induce a Mature and Stable Vascular Network—a Future Therapy for Ischemically Challenged Tissue

“…Expression cassettes consisting of the CMV ie -promoter that encode for regions that are separated by the poliovirus IRES element (black box) and the SV40 polyadenylation signal were demonstrated previously [8]. Using the methods of cosmid cloning, the expression cassettes are integrated into the E1 position of the adenocosmid vector pAdcos45 (36 kb) containing the complete E1/E3 deleted AdV type 5 genome.…”

“…Isogenic fibroblasts were harvested as described before [8]. Recombinant adenoviruses were obtained from the German Research Centre for Biotechnology (Braunschweig, Germany).…”

“…by tissue hypoxia [6] leads to the activated transcription of numerous genes, including VEGF [6], but appears to be only one facet of a complex system of angiogenesis and arteriogenesis. Obviously, high levels of VEGF 165 or basic fibroblast growth factor (bFGF) alone do not lead to functional arteriogenesis [7,8]. As described by Rhodin and Fujita, the maturation of arterial vessels does not only require sprouting and budding from pre-existing vessels, but also a tightening of the vessel by pericytes clumping to the fragile vessel wall [9].…”

“…We further investigated the in vivo effect of VEGF 165 -modified fibroblasts on healthy and ischemic tissue. In a random-pattern flap model, the temporary expression of VEGF 165 induced therapeutically relevant angiogenesis and improved the blood supply if modified cells were applied one week prior to the induction of tissue ischemia [8].…”

Morphology and Hemodynamics during Vascular Regeneration in Critically Ischemic Murine Skin Studied by Intravital Microscopy Techniques

“…Up to date, each of these mechanisms has predominantly been investigated as an isolated process, whereas there is a paucity of data documenting these integral processes in the living tissue over time. Previous in vivo studies have been restricted to the analysis of necrotic flap area or single time-point experiments, or focused on acute phenomena of vasoregulation [1,2], ischemia and ischemia reperfusion experiments [3,4,5] and tissue survival studies [6,7]. Recently, the attempt has been made to study angiogenesis over time [6,8].…”