Polarized secretion of tissue-plasminogen activator in cultured thyroid cells.
We studied the polarized secretion of tissue-type plasminogen activator in porcine thyroid cells cultured as a monolayer on porous bottom chambers. The presence of tissue-type plasminogen activator was detected by zymographic analysis on two independent media that were in contact either with the apical surface or with the basolateral membrane. The amount of tissue-type plasminogen activator was determined in both media by ELISA and enzyme assay. Measurable tissue-type plasminogen activator activity was found in the basal but not in the apical medium. However, on zymogram, a lytic zone corresponding to tissue-type plasminogen activator was visible in both media. In addition, a lytic band at 130 kDa suggested presence of a complex formed by tissue-type plasminogen activator and an inhibitor. Preferential basolateral tissue-type plasminogen activator antigen secretion (70%) has been observed, showing the possible relation between tissue-type plasminogen activator and extracellular matrix components. Neither tissue-type plasminogen activator level nor polarized secretion seemed to be regulated by thyrotropin (0.1 mU/ml).
Desruisseau-Gonzalvez
S
S
INSERM U.270, Faculté de médecine Nord, Marseille, France.
Delori
P
P
Gruffat
D
D
Chabaud
O
O
D000818:Animals; D002478:Cells, Cultured; D003470:Culture Media; D004797:Enzyme-Linked Immunosorbent Assay; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects / Q000201:enzymology; D007700:Kinetics; D013552:Swine; D013961:Thyroid Gland / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D013972:Thyrotropin / Q000494:pharmacology; D010959:Tissue Plasminogen Activator / Q000032:analysis / Q000378:metabolism*
D003470:Culture Media; D013972:Thyrotropin; D010959:Tissue Plasminogen Activator