VEGF transfer based on gene-modified fibroblasts using a hypoxia-induced vector to modulate neoangiogenesis in ischaemic regions of myocutaneous transplants

Does survivin overexpression enhance the efficiency of fibroblast cell-based wound therapy?

Cell-based wound therapy is faced with some limiting factors that decrease the therapeutic efficacy of transplanted cells. In this study, we aimed to genetically modify fibroblast cells with anti-apoptotic Survivin gene (Birc5) before cell transplantation. In vitro, pIRES2-eGFP-Survivin plasmid was transfected into the fibroblast cells and the growth curve was evaluated for transfected and normal cells performing MTT assay. In vivo, two 6-diameter cutaneous wounds were created at mice dorsal skin. Fibrin clot was used as a delivery vehicle to transfer cells into the wound bed. The effects of four treatment groups including (a) Cell-SVV-Clot (b) Cell-GFP-Clot, (c) Normal cell-Clot and, (d) Clot alone were evaluated. After 1,2,3,7 and 14 days post-transplantation, the wounds were photographed for evaluating the wound closure rate and wound samples were obtained. Angiogenesis and formation of granulated tissue were assessed via H&E staining for wound samples. The expression levels of Survivin, VEGF, and bFGF genes were also determined using qRT-PCR. The MTT assay showed similar proliferation potential of transfected cells with normal cells verifying that Survivin had no detrimental effect. Compared to the Normal cell-Clot group, the Survivin overexpression was seen for 3 days in the Cell-SVV-Clot group verifying the cell survival during the early stage of wound healing. The Survivin further upregulated VEGF and bFGF expressions resulting in more angiogenesis and formation of granulated tissue by day 3 and 14. The treated wounds with Cell-SVV-Clot were regenerated with a higher wound closure rate by day 7 compared to Normal cell-Clot and Clot groups. Survivin enhanced wound healing through induction of VEGF and bFGF at particular times post-wounding that led to a more structured-epidermis with higher angiogenesis and granulation tissue formation rate.