Role of urokinase and its receptor in basal and stimulated colonic epithelial cell migration in vitro.
BACKGROUND
Migration of colonic epithelial cells is important for mucosal repair following injury. The urokinase (u-PA) system regulates migration in other cell types.


OBJECTIVE
To examine the role of u-PA and its receptor (u-PAR) in colonic epithelial cell migration.


METHODS
Migration was assessed over 24 hours in circular wounds made in confluent monolayers of LIM1215 and Caco-2 human colon cancer cells. The function of u-PA and u-PAR was ablated with antisense oligonucleotides to block expression, with synthetic u-PA peptides to block interaction, and with aprotinin to block u-PA mediated proteolysis.


RESULTS
Migration was stimulated two to threefold by exogenous u-PA, an effect dependent on u-PAR binding but independent of u-PA mediated mitogenesis and proteolysis. Expression of u-PA and u-PAR was inhibited by 80% by the appropriate antisense oligonucleotide. Basal migration and the motogenic effects of butyrate, epidermal growth factor, and phorbol-12-myristate-13-acetate were suppressed by the u-PAR antisense oligonucleotide (40-60%) but were at best minimally affected following inhibition of u-PA expression and binding.


CONCLUSIONS
In an in vitro model of wounded colonic epithelium, u-PAR promotes cell migration through mechanisms that are not exclusively dependent on u-PA binding. Therefore, u-PA and u-PAR may contribute to colonic mucosal repair in vivo.
Wilson
A J
AJ
Department of Medicine, University of Melbourne, Royal Melbourne Hospital, Victoria 3050, Australia.
Gibson
P R
PR
D002087:Butyrates / Q000494:pharmacology; D018938:Caco-2 Cells; D002455:Cell Division / Q000502:physiology; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D003106:Colon / Q000201:enzymology* / Q000293:injuries / Q000473:pathology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D004847:Epithelial Cells / Q000502:physiology*; D006801:Humans; D016376:Oligonucleotides, Antisense / Q000235:genetics; D011956:Receptors, Cell Surface / Q000235:genetics / Q000502:physiology*; D055293:Receptors, Urokinase Plasminogen Activator; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014568:Urokinase-Type Plasminogen Activator / Q000235:genetics / Q000494:pharmacology / Q000502:physiology*
D002087:Butyrates; D016376:Oligonucleotides, Antisense; C524898:PLAUR protein, human; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D004815:Epidermal Growth Factor; D014568:Urokinase-Type Plasminogen Activator; D013755:Tetradecanoylphorbol Acetate