The subsets of keratinocytes responsible for covering open wounds in neonatal rat skin
- 107 Downloads
Full-thickness excisional wounds were made on the dorsal skin of 1-day-old rats to elucidate from where the cells move into the defect and what kinds of cells they are. Immunohistochemical analyses of the wound sites revealed that the following two subsets of keratinocytes were the major contributors to reepithelialization: first, the cells at the forefront of the migrating epithelium, termed “leading edge cells,” which expressed K14 keratin, known as basal cell-specific keratin, but not K6 or K10 keratins, so that they had probably moved from the basal cell layer; and, second, the cells tentatively termed “immature spinous cells,” which expressed K14 and K6 but not K10, and formed an “ingrowth region” following the leading edge cells. These two kinds of cells moved to the open wound area, as a multilayered cell sheet. Fluorescent phalloidin staining experiments indicated that actin filaments became concentrated in the leading edge cells within 6 h postwounding (PW), whereas weak signals of actin filaments were detected in the immature spinous cells. Taken together, the present findings support the view that wound covering in neonatal rat skin is accomplished by a movement en masse of keratinocytes from the bottom half of the surrounding epidermis.
KeywordsWound Reepithelialization Keratinocyte Keratin Actin Rat (Sprague Dawley)
We thank Dr. M. Kuroda, Shimane University, for kindly providing the Texas-red-conjugated phalloidin.
- Burrington JD (1971) Wound healing in the fetal lamb. J Pediatric Surg 6:523–528Google Scholar
- Dixon JB (1960) Inflammation in the foetal and neonatal rat: the local reactions to skin burns. J Pathol Bact 80:73–82Google Scholar
- Longaker MT, Adzick NS (1990) The biology of fetal wound healing: a review. Plast Reconst Surg 87:788–798Google Scholar
- Longaker MT, Whitby DJ, Adzick NS, Crombleholme TM, Langer JC, Duncan BW, Bradley SM, Stern R, Ferguson MWJ, Harrison MR (1990) Studies in fetal wound healing, VI. Second and early third trimester fetal wounds demonstrate rapid collagen deposition without scar formation. J Pediatric Surgery 25:63–69Google Scholar
- Martin P (1996) Mechanisms of wound healing in the embryo and fetus. Curr Topics Dev Biol 32:175–203Google Scholar
- Samuels P, Tan AKW (1999) Fetal scarless wound healing. J Otolaryngology 28:296–302Google Scholar
- Sezaki K, Uchinuma E, Shioya N, Ihara S (2000) Localization of K6-keratin mRNA in newborn rat wounds during healing. Kitasato Med 30:400–406Google Scholar