title: Regulable vascular endothelial growth factor165 overexpression by ex vivo expanded keratinocyte cultures promotes matrix formation, angiogenesis, and healing in porcine full-thickness wounds.
abstract: The intricate wound repair process involves the interplay of numerous cells and proteins. Using a porcine full-thickness wound (FTW) healing model, we hypothesized that the ex vivo gene transfer of vascular endothelial growth factor (VEGF)-transfected basal keratinocyte (KC) cell suspensions may generate cross-talk and induce matrix formation, angiogenesis, and accelerated healing. Moreover, to regulate overexpression of isoform 165 of VEGF and its effect on healing, we introduced a tetracycline (TC)-inducible gene switch in the expression plasmid. Autologous basal KCs were cultivated from the porcine donor and transfected using cationic liposomes. A dose-response curve was established to determine optimal activation of the gene switch by TC. In vivo, FTWs were treated with VEGF-transfected KCs and controls. Wound fluids were collected daily and examined using enzyme-linked immunosorbent assay. Biopsies were evaluated using hematoxylin and eosin and immunostaining for fibronectin, CD144, and lectin BS-1. In vitro, highest regulable VEGF165-expression was obtained with 1 microg/mL of TCs. In vivo, after induction of the gene switch by adding 1 microg/mL of TCs to the FTW, we obtained upregulated VEGF165 levels and enhanced fibronectin deposition and found more endothelial cell tubular formations and higher rates of reepithelialization than in controls. This ex vivo gene transfer model may serve as a platform for vascular induction in full-thickness tissue repair.
authors.affiliation: Laboratory of Plastic Surgery and Tissue Engineering Research, Department of Plastic and Reconstructive Surgery, KU Leuven University Hospital, Katholieke Universiteit, Leuven, Belgium.
authors.forename: Stijn
authors.initials: S
authors.lastname: Dickens
authors.forename: Pieter
authors.initials: P
authors.lastname: Vermeulen
authors.forename: Benoit
authors.initials: B
authors.lastname: Hendrickx
authors.forename: Stefaan
authors.initials: S
authors.lastname: Van den Berge
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Vranckx
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002478:Cells, Cultured; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000378:metabolism / Q000473:pathology; D005109:Extracellular Matrix / Q000378:metabolism*; D005353:Fibronectins / Q000096:biosynthesis; D015870:Gene Expression; D015603:Keratinocytes / Q000378:metabolism* / Q000473:pathology / Q000637:transplantation; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000235:genetics; D013552:Swine; D013752:Tetracycline / Q000494:pharmacology; D014162:Transfection; D014182:Transplantation, Autologous; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis* / Q000235:genetics; D014945:Wound Healing / Q000187:drug effects / Q000235:genetics; D014947:Wounds and Injuries / Q000235:genetics / Q000473:pathology / Q000628:therapy*
chemical_list: D000900:Anti-Bacterial Agents; D005353:Fibronectins; D042461:Vascular Endothelial Growth Factor A; D013752:Tetracycline