Onset of re-epithelialization after skin injury correlates with a reorganization of keratin filaments in wound edge keratinocytes: defining a potential role for keratin 16

J Cell Biol. 1996 Feb;132(3):381-97. doi: 10.1083/jcb.132.3.381.

Abstract

Injury to stratified epithelia causes a strong induction of keratins 6 (K6) and 16 (K16) in post-mitotic keratinocytes located at the wound edge. We show that induction of K6 and K16 occurs within 6 h after injury to human epidermis. Their subsequent accumulation in keratinocytes correlates with the profound reorganization of keratin filaments from a pan-cytoplasmic distribution to one in which filaments are aggregated in a juxtanuclear location, opposite to the direction of cell migration. This filament reorganization coincides with additional cytoarchitectural changes and the onset of re-epithelialization after 18 h post-injury. By following the assembly of K6 and K16 in vitro and in cultured cells, we find that relative to K5 and K14, a well-characterized keratin pair that is constitutively expressed in epidermis, K6 and K16 polymerize into short 10-nm filaments that accumulate near the nucleus, a property arising from K16. Forced expression of human K16 in skin keratinocytes of transgenic mice causes a retraction of keratin filaments from the cell periphery, often in a polarized fashion. These results imply that K16 may not have a primary structural function akin to epidermal keratins. Rather, they suggest that in the context of epidermal wound healing, the function of K16 could be to promote a reorganization of the cytoplasmic array of keratin filaments, an event that precedes the onset of keratinocyte migration into the wound site.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Animals
  • Cells, Cultured
  • Cloning, Molecular
  • DNA, Complementary
  • Epidermis / pathology
  • Epidermis / physiology
  • Epithelium / physiology
  • Escherichia coli
  • Fibroblasts / cytology
  • Fibroblasts / physiology
  • Gene Expression
  • Humans
  • Immune Sera
  • Keratinocytes / pathology
  • Keratinocytes / physiology*
  • Keratins / biosynthesis
  • Keratins / physiology*
  • Keratins / ultrastructure
  • Mice
  • Mice, Transgenic
  • Microscopy, Electron
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / ultrastructure
  • Skin / injuries*
  • Skin / pathology
  • Skin Physiological Phenomena
  • Wound Healing*

Substances

  • DNA, Complementary
  • Immune Sera
  • Recombinant Proteins
  • Keratins