title: Interleukin 1 preferentially stimulates the production of tissue-type plasminogen activator by human articular chondrocytes.
abstract: Interleukin 1, derived from human placenta, stimulates plasminogen activator activity in human articular chondrocytes. The stimulation of plasminogen activator activity can be abolished by preincubation of placental interleukin 1 with an antiserum to homogeneous 22K factor, a species of interleukin 1 beta, indicating that the stimulation of plasminogen activator activity is due to interleukin 1 and not contaminating factors. Chondrocytes produce three species of plasminogen activator, with apparent Mr approximately 50,000, 65,000 and 100,000 as determined after sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis with gels containing casein and plasminogen. Both placental interleukin 1 and 22K factor enhance the production of the species of Mr approximately 65,000 and 100,000. Comparison of the mobility of the plasminogen activator species on SDS-polyacrylamide gel electrophoresis with human urokinase (u-PA) and human melanoma tissue-type plasminogen activator (t-PA) and studies with antibodies to these enzymes indicate that the Mr approximately 50,000 species is a u-PA and the Mr approximately 65,000 a t-PA. The Mr approximately 100,000 species is possibly an enzyme-inhibitor complex. Interleukin 1 therefore appears to enhance the production of t-PA and a putative enzyme-inhibitor complex. Abolition of plasminogen activator activity in the fibrin plate assay with antibodies to t-PA and u-PA also confirms enhanced t-PA production on interleukin 1 stimulation, though there is also evidence for increased cell-associated production of u-PA.
mesh_terms: D002358:Cartilage, Articular / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007120:Immunochemistry; D066298:In Vitro Techniques; D007375:Interleukin-1 / Q000502:physiology*; D010920:Placenta / Q000378:metabolism; D010960:Plasminogen Activators / Q000096:biosynthesis; D011247:Pregnancy; D010959:Tissue Plasminogen Activator / Q000096:biosynthesis*
chemical_list: D007375:Interleukin-1; D010960:Plasminogen Activators; D010959:Tissue Plasminogen Activator