Polarized secretion of plasminogen activators by epithelial cell monolayers.
We have investigated the synthesis and the polarized secretion of plasminogen activators (PAs) in three epithelial cell lines (FRT, derived from rat thyroid; MDCK, from canine kidney, and CaCo-2, from human intestine) grown on filters, in bicameral systems. Confluency and acquisition of functional polarity were assessed by measuring transepithelial resistance and by showing polarized secretion of endogenous proteins. By zymography, before and after immunoprecipitation with specific antibodies, we found that FRT cells synthesized tissue plasminogen activator (tPA) and that tPA activity was mostly confined to the apical cell compartment. MDCK and CaCo-2 cells, instead, synthesized urokinase-type plasminogen activator (uPA). In MDCK cells the uPA activity was found predominantly in the apical cell compartment while in CaCo-2 cells it was mostly basolateral.
Canipari
R
R
Istituto di Istologia ed Embriologia Generale, Facoltà di Medicina, Università degli Studi di Roma La Sapienza, Italy.
Zurzolo
C
C
Polistina
C
C
Garbi
C
C
Aloj
L
L
Calì
G
G
Gentile
R
R
Nitsch
L
L
D000818:Animals; D002451:Cell Compartmentation; D002460:Cell Line / Q000378:metabolism; D016764:Cell Polarity; D003470:Culture Media; D004285:Dogs; D004848:Epithelium / Q000378:metabolism; D006801:Humans; D010960:Plasminogen Activators / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D014568:Urokinase-Type Plasminogen Activator / Q000096:biosynthesis
D003470:Culture Media; D010960:Plasminogen Activators; D014568:Urokinase-Type Plasminogen Activator