Plasminogen activator inhibitor type 2 is expressed in keratinocytes during re-epithelialization of epidermal defects.
Plasminogen activation is observed in the human epidermis during re-epithelialization of epidermal defects. The activation reaction depends on plasminogen activators (PAs) associated with re-epithelializing keratinocytes. PA inhibitor type 2 (PAI-2) is thought to be a major epidermal PA inhibitor in keratinocytes. However, no data are available on the expression of PAI-2 in keratinocytes during epidermal regeneration. We have therefore analysed PAI-2 at the mRNA and protein level in keratinocyte cultures as well as in epidermal lesions in which re-epithelializing keratinocytes were apparent. We found that PAI-2 expression at the mRNA and protein level was negatively correlated with the cell density in regular keratinocyte cultures. In organotypic cocultures, in which the transition from a re-epithelializing to a sedentary phenotype can be studied, PAI-2 was most strongly expressed in early cultures prior to formation of a differentiated epidermis-like structure. We found a strong expression of PAI-2 in keratinocytes that re-epithelialized dermal burn wounds or lesions caused by the autoimmune blistering disease pemphigus vulgaris. Our results suggest that not only PAs, but also a major PA inhibitor, PAI-2, are expressed in keratinocytes that are actively involved in re-epithelialization.
Bechtel
M J
MJ
University Institute for Immunology, Laboratory for Immunopathology, Heidelberg, Germany.
Wysocki
N S
NS
Heidtmann
A
A
Stark
H J
HJ
Fusenig
N
N
Kramer
M D
MD
Schaefer
B M
BM
D015152:Blotting, Northern; D002056:Burns / Q000378:metabolism / Q000473:pathology; D018929:Cell Culture Techniques; D004817:Epidermis / Q000378:metabolism* / Q000473:pathology; D004848:Epithelium / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D006801:Humans; D017403:In Situ Hybridization; D015603:Keratinocytes / Q000378:metabolism*; D008297:Male; D010392:Pemphigus / Q000378:metabolism / Q000473:pathology; D017396:Plasminogen Activator Inhibitor 2 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D014945:Wound Healing / Q000502:physiology*
D017396:Plasminogen Activator Inhibitor 2; D012333:RNA, Messenger