Differentiating cells of murine stratified squamous epithelia constitutively express plasminogen activator inhibitor type 2 (PAI-2).
Histochem Cell Biol
; 110(6): 559-69, 1998 Dec.
Article
in En
| MEDLINE
| ID: mdl-9860254
ABSTRACT
In stratified squamous epithelia a critical balance among cell proliferation, differentiation, and death must be maintained in order for these tissues to fulfill their barrier function. Previous studies have demonstrated that plasminogen activator inhibitor 2 (PAI-2) is a product of differentiating epidermal keratinocytes, suggesting a role for this inhibitor during squamous differentiation. Furthermore, in certain tumor cell lines, overexpression of PAI-2 confers resistance to the induction of programmed cell death, suggesting cytoprotective function(s). In the present study we demonstrate that PAI-2 mRNA and protein are constitutively and uniquely expressed in differentiating cells of murine stratified squamous epithelia, including epidermis, esophagus, vagina, oral mucosa, and tongue. PAI-2 immunohistochemical localization patterns suggest a predominantly cytosolic distribution, consistent with biochemical identification of the major PAI-2 species as a 43-kDa, presumably non-glycosylated protein. Functional analysis shows that the majority of epithelial PAI-2 is active. In contrast to the high levels of PAI-2 expression in stratified squamous epithelia, little or no PAI-2 is detectable in simple epithelia. These findings suggest that epithelial PAI-2 may mediate inhibition of intracellular proteinases associated with events during terminal differentiation and death that are unique to stratified squamous epithelia.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Serine Proteinase Inhibitors
/
Plasminogen Activator Inhibitor 2
/
Epithelial Cells
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
Histochem Cell Biol
Journal subject:
CITOLOGIA
/
HISTOCITOQUIMICA
Year:
1998
Document type:
Article
Affiliation country:
Estados Unidos