Identification of the calcium-inducible plasminogen activators secreted by a human diploid fibroblast cell line (MRC-5).
Human embryonic lung fibroblast (MRC5) cells secreted small amounts of plasminogen activators into normal, serum-free harvest medium. Stimulation with calcium led to markedly enhanced levels of activator. The major species of plasminogen activator in the harvest medium of the stimulated cultures resembled u-PA when analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis followed by fibrin zymography. This activator was partially-purified using controlled-pore glass and Blue Sepharose CL6B. Characterisation by fibrin zymography in the presence of specific antibody, by 3H-DFP labelling and by fibrin-binding ability indicated that the activator was indistinguishable from high molecular weight u-PA. The possible physiological role of the production of relatively large amounts of u-PA by a lung cell capable of producing both u-PA and t-PA is discussed.
D002118:Calcium / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D005337:Fibrin / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects; D006801:Humans; D007531:Isoflurophate / Q000378:metabolism; D008168:Lung / Q000196:embryology; D010960:Plasminogen Activators / Q000378:metabolism*; D011485:Protein Binding
D007531:Isoflurophate; D005337:Fibrin; D010960:Plasminogen Activators; D002118:Calcium