Oxidant-induced vascular endothelial growth factor expression in human keratinocytes and cutaneous wound healing.
Neutrophils and macrophages, recruited to the wound site, release reactive oxygen species by respiratory burst. It is commonly understood that oxidants serve mainly to kill bacteria and prevent wound infection. We tested the hypothesis that oxidants generated at the wound site promote dermal wound repair. We observed that H(2)O(2) potently induces vascular endothelial growth factor (VEGF) expression in human keratinocytes. Deletion mutant studies with a VEGF promoter construct revealed that a GC-rich sequence from bp -194 to -50 of the VEGF promoter is responsible for the H(2)O(2) response. It was established that at microm concentrations oxidant induces VEGF expression and that oxidant-induced VEGF expression is independent of hypoxia-inducible factor (HIF)-1 and dependent on Sp1 activation. To test the effect of NADPH oxidase-generated reactive oxygen species on wound healing in vivo, Rac1 gene transfer was performed to dermal excisional wounds left to heal by secondary intention. Rac1 gene transfer accelerated wound contraction and closure. Rac1 overexpression was associated with higher VEGF expression both in vivo as well in human keratinocytes. Interestingly, Rac1 gene therapy was associated with a more well defined hyperproliferative epithelial region, higher cell density, enhanced deposition of connective tissue, and improved histological architecture. Overall, the histological data indicated that Rac1 might be an important stimulator of various aspects of the repair process, eventually enhancing the wound-healing process as a whole. Taken together, the results of this study indicate that wound healing is subject to redox control.
Sen
Chandan K
CK
Laboratory of Molecular Medicine, Dorothy M. Davis Heart and Lung Research Institute, Department of Surgery (Center for Minimally Invasive Surgery), The Ohio State University Medical Center, Columbus, Ohio 43210, USA. sen-1@medctr.osu.edu
Khanna
Savita
S
Babior
Bernard M
BM
Hunt
Thomas K
TK
Ellison
E Christopher
EC
Roy
Sashwati
S
D000818:Animals; D002460:Cell Line; D003094:Collagen / Q000378:metabolism; D016228:Endothelial Growth Factors / Q000378:metabolism*; D017353:Gene Deletion; D018014:Gene Transfer Techniques; D049452:Green Fluorescent Proteins; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D015151:Immunoblotting; D015603:Keratinocytes / Q000378:metabolism*; D008156:Luciferases / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism; D008222:Lymphokines / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D019255:NADPH Oxidases / Q000378:metabolism; D009389:Neovascularization, Pathologic; D016877:Oxidants / Q000494:pharmacology*; D010084:Oxidation-Reduction; D019000:Phosphotyrosine / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012260:Ribonucleases / Q000378:metabolism; D012867:Skin / Q000473:pathology; D012879:Skin Physiological Phenomena; D013997:Time Factors; D015533:Transcriptional Activation; D014162:Transfection; D014407:Tumor Cells, Cultured; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D014945:Wound Healing; D020830:rac1 GTP-Binding Protein / Q000378:metabolism
D016228:Endothelial Growth Factors; D008164:Luminescent Proteins; D008222:Lymphokines; D016877:Oxidants; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D049452:Green Fluorescent Proteins; D019000:Phosphotyrosine; D003094:Collagen; D006861:Hydrogen Peroxide; D008156:Luciferases; D019255:NADPH Oxidases; D012260:Ribonucleases; D020830:rac1 GTP-Binding Protein