title: Transforming growth factor-beta and its effect on reepithelialization of partial-thickness ear wounds in transgenic mice.
abstract: Transforming growth factor-beta (TGF-beta) is known to affect nearly every aspect of wound repair. Many of the effects have been extensively investigated; however, the primary effect of endogenously derived TGF-beta on wound reepithelialization is still not completely understood. To examine this, two types of wounds were made on a transgenic mouse over-expressing TGF-beta1. Full-thickness back wounds were made to compare the wound healing process in the presence of compensatory healing mechanisms. Superficial partial-thickness ear wounds involving only the epidermis were made to determine the effect of TGF-beta on reepithelialization. In the partial-thickness ear wounds, at later time points, the transgenic group had smaller epithelial gaps than the wild-type mice. A greater number of actively proliferating cells, as determined by bromodeoxyuridine incorporation, was also found in the transgenic mice at post-injury day 8. These results show that TGF-beta1 stimulates the rate of reepithelialization at later time points in partial-thickness wounds. However, in the full-thickness back wounds, the transgenic animals exhibited a slower reepithelialization rate at all time points and the number of bromodeoxyuridine-positive cells was fewer. Our findings would suggest that the overexpression of TGF-beta1 speeds the rate of wound closure in partial-thickness wounds by promoting keratinocyte migration. In full-thickness wounds, however, the overexpression of TGF-beta1 slows the rate of wound reepithelialization.
authors.affiliation: Department of Surgery, Division of Plastic Surgery, Wound Healing Research Group, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Eric B
authors.initials: EB
authors.lastname: Tredget
authors.forename: Jack
authors.initials: J
authors.lastname: Demare
authors.forename: Geethan
authors.initials: G
authors.lastname: Chandran
authors.forename: Edward E
authors.initials: EE
authors.lastname: Tredget
authors.forename: Liju
authors.initials: L
authors.lastname: Yang
authors.forename: Aziz
authors.initials: A
authors.lastname: Ghahary
mesh_terms: D000818:Animals; D001415:Back; D002465:Cell Movement / Q000502:physiology; D004423:Ear; D004848:Epithelium / Q000503:physiopathology*; D015603:Keratinocytes / Q000502:physiology; D051379:Mice; D008822:Mice, Transgenic; D023421:Models, Animal; D016212:Transforming Growth Factor beta / Q000502:physiology*; D014945:Wound Healing / Q000502:physiology*; D014947:Wounds and Injuries / Q000503:physiopathology
chemical_list: D016212:Transforming Growth Factor beta