SERPINE1 (PAI-1) is deposited into keratinocyte migration "trails" and required for optimal monolayer wound repair

Arch Dermatol Res. 2008 Jul;300(6):303-10. doi: 10.1007/s00403-008-0845-2. Epub 2008 Apr 2.

Abstract

Cutaneous tissue injury, both in vivo and in vitro, initiates activation of a "wound repair" transcriptional program. One such highly induced gene encodes plasminogen activator inhibitor type-1 (PAI-1, SERPINE1). PAI-1-GFP, expressed as a fusion protein under inducible control of +800 bp of the wound-activated PAI-1 promoter, prominently "marked" keratinocyte migration trails during the real-time of monolayer scrape-injury repair. Addition of active recombinant PAI-1 to wounded wild-type keratinocyte monolayers as well as to PAI-1(-/-) MEFs and PAI-1(-/-) keratinocytes significantly stimulated directional motility above basal levels in all cell types. PAI-1 expression knockdown or antibody-mediated functional inhibition, in contrast, effectively attenuated injury repair. The defect in wound-associated migratory activity as a consequence of antisense-mediated PAI-1 down-regulation was effectively reversed by addition of recombinant PAI-1 immediately after scrape injury. One possible mechanism underlying the PAI-1-dependent motile response may involve fine control of the keratinocyte substrate detachment/re-attachment process. Exogenous PAI-1 significantly enhanced keratinocyte spread cell "footprint" area while PAI-1 neutralizing antibodies, but not control non-immune IgG, effectively inhibited spreading with apoptotic hallmarks evident within 24 h. Importantly, PAI-1 not only stimulated keratinocyte adhesion and wound-initiated planar migration but also rescued keratinocytes from plasminogen-induced substrate detachment/anoikis. The early transcriptional response of the PAI-1 gene to monolayer trauma and its prominence in the injury repair genetic signature are consistent with its function as both a survival factor and regulator of the time course of epithelial migration as part of the cutaneous injury response program.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Anoikis / genetics
  • Antibodies, Blocking
  • Cell Adhesion / genetics
  • Cell Line
  • Cell Movement / genetics
  • Cell Surface Extensions / genetics
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Humans
  • Keratinocytes / metabolism*
  • Keratinocytes / pathology
  • Mice
  • Mice, Knockout
  • Plasminogen Activator Inhibitor 1 / genetics
  • Plasminogen Activator Inhibitor 1 / metabolism*
  • RNA, Small Interfering / genetics
  • Rats
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Transfection
  • Wound Healing*

Substances

  • Antibodies, Blocking
  • Plasminogen Activator Inhibitor 1
  • RNA, Small Interfering
  • Recombinant Fusion Proteins
  • Green Fluorescent Proteins