Involucrin-positive keratinocytes demonstrate decreased migration speed but sustained directional migration in a DC electric field.
When skin is wounded, keratinocytes from the cut edges of the epidermis migrate over the wounded area to re-epithelialize the wound. It is not clear which cells of the epidermis have the capacity to migrate and contribute to this re-epithelialization: the less differentiated cells of the basal layer, or the more differentiated, involucrin-positive suprabasilar cells. Here we demonstrate that both involucrin-negative and involucrin-positive cells are able to respond to a directional cue for migration with sustained directional migration. When cultured keratinocytes are exposed to a physiologic DC electric field of 100 mV per mm as a cue to guide migration (galvanotaxis) they migrate toward the cathode with equivalent directionality. The involucrin-positive cells, however, display mean migration speeds approximately one half (23.6 microm per h) of the mean rate achieved by involucrin-negative cells (46.5 microm per h). Despite their decreased migration rates, involucrin-positive cells appear to possess an intact mechanism for sensing a directional signal, transducing that signal, and responding with sustained directional migration. Because electric fields are endogenous in skin wounds, it is likely that both the basal, involucrin-negative cells and the involucrin-positive suprabasilar cells respond to this cue with directional migration. The new observation that involucrin-positive cells can indeed migrate suggests that these cells may also contribute to wound re-epithelialization in vivo.
Obedencio
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Department of Dermatology, University of California, Davis 95616, USA.
Nuccitelli
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Isseroff
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D002454:Cell Differentiation / Q000502:physiology; D002465:Cell Movement / Q000528:radiation effects; D002478:Cells, Cultured; D004560:Electricity; D004566:Electrodes; D006801:Humans; D007231:Infant, Newborn; D015603:Keratinocytes / Q000737:chemistry* / Q000166:cytology*; D008297:Male; D011498:Protein Precursors / Q000032:analysis*; D014945:Wound Healing / Q000502:physiology
D011498:Protein Precursors; C032253:involucrin