Combined vascular endothelial growth factor-A and fibroblast growth factor 4 gene transfer improves wound healing in diabetic mice

Abstract

BackgroundImpaired wound healing in diabetes is related to decreased production of growth factors. Hence, gene therapy is considered as promising treatment modality. So far, efforts concentrated on single gene therapy with particular emphasis on vascular endothelial growth factor-A (VEGF-A). However, as multiple proteins are involved in this process it is rational to test new approaches. Therefore, the aim of this study was to investigate whether single AAV vector-mediated simultaneous transfer of VEGF-A and fibroblast growth factor 4 (FGF4) coding sequences will improve the wound healing over the effect of VEGF-A in diabetic (db/db) mice.MethodsLeptin receptor-deficient db/db mice were randomized to receive intradermal injections of PBS or AAVs carrying β-galactosidase gene (AAV-LacZ), VEGF-A (AAV-VEGF-A), FGF-4 (AAV-FGF4-IRES-GFP) or both therapeutic genes (AAV-FGF4-IRES-VEGF-A). Wound healing kinetics was analyzed until day 21 when all animals were sacrificed for biochemical and histological examination.ResultsComplete wound closure in animals treated with AAV-VEGF-A was achieved earlier (day 19) than in control mice or animals injected with AAV harboring FGF4 (both on day 21). However, the fastest healing was observed in mice injected with bicistronic AAV-FGF4-IRES-VEGF-A vector (day 17). This was paralleled by significantly increased granulation tissue formation, vascularity and dermal matrix deposition. Mechanistically, as shown in vitro, FGF4 stimulated matrix metalloproteinase-9 (MMP-9) and VEGF receptor-1 expression in mouse dermal fibroblasts and when delivered in combination with VEGF-A, enhanced their migration.ConclusionCombined gene transfer of VEGF-A and FGF4 can improve reparative processes in the wounded skin of diabetic mice better than single agent treatment.

Effect of low-intensity direct current on expression of vascular endothelial growth factor and nitric oxide in diabetic foot ulcers

“…VEGF, as an important angiogenic factor, and NO, as a vasodilator, play a potent role in the formation of new vessels (angiogenesis) in the wound healing process [8][9][10][11]17]. There is evidence that the expression of VEGF and NO is reduced in patients with diabetes, and this diminution is associated with delayed healing in the wounds [12,[24][25]. The results of the present study showed that the plasma level of VEGF in patients with DFU was higher than that in normal age-matched subjects, but the NO level in these patients was lower than that in the normal subjects.…”

“…VEGF, as a direct angiogenic factor, has a main role in angiogenesis [8][9][10][11]. Evidence exists that expression of growth factors such as VEGF reduce the occurrence of DFU [12][13].…”

Biomaterials for Promoting Wound Healing in Diabetes

“…However, these molecules are degraded quite fast by enzymes existing in the protease-rich wound environment [30]. Therefore, researchers have developed controlledrelease systems which are able to provide an efficient concentration of those functional molecules at the wound site during the healing process as well as protect the growth factors and cytokines from degradation and inactivation [31,32]. The release of the molecules was maintained by encapsulating nanoparticles, vectors (virus, plasmid, DNA, etc.)…”

Investigation of The Wound Healing Effects of Chitosan on FGFR3 and VEGF Immunlocalization in Experimentally Diabetic Rats

“…Vascular endothelial growth factor (VEGF) is a multifunctional growth factor produced by endothelial cells, fibroblasts, smooth muscle cells, trombocytes, neutrophils and macrophages.Its function is to elicit proliferation, migration and differentiation of the said cells (24)(25)(26).Studies on wound healing process in experimentally diabetic animals have shown that several growth factors, including VEGF, are dramatically decreased (27)(28)(29).It has been suggested that administration of VEGF-A via protein or gene transfer methods increases granulation tissue formation, angiogenesis and matrix deposition in experimentally diabetic mice (27).…”

“…Fibroblast growth factor (FGF) demonstrates strong mitogenic properties in fibroblasts, osteoblasts, smooth muscle cells, endothelial cells, chondrocytes and melanocytes (27)(28)(29)(30).It is one of the most important growth factors playing crucial roles in embryonic development, angiogenesis and wound healing.Biologically, it acts via binding to the cellular surface receptors belonging to the tyrosine kinase receptor family. Four of such surface receptors (FGFR 1-4) have been identified up until now (31)(32)(33).It has been clearly demonstrated in previous studies that FGFR3 is localized in the suprabasal region of epidermis, in the inner epidermal root sheat of hair follicles, in the smooth musle cells of blood vessels of the normal skin tissue whereas FGFR3 is immunolocalized in the suprabasal and basal layers of epidermis, around the blood vessels of the granulation tissue, in fibroblasts and inflammatory cells of the skin during wound healing process (33).However, the number of histopathological studies on VEGF immunolocalization is still limited while there exist no studies on FGFR-3 in wound healing process in diabetic subjects.…”