title: Human mast cell chymase and leukocyte elastase release latent transforming growth factor-beta 1 from the extracellular matrix of cultured human epithelial and endothelial cells.
abstract: Monolayer cultures of human epithelial and endothelial cells were used to study the association of latent transforming growth factor-beta 1 (TGF-beta 1) to extracellular matrices and its release and activation during matrix degradation. Human umbilical vein endothelial cells and embryonic lung fibroblasts produced relatively high levels of TGF-beta 1, its propeptide (beta 1-latency-associated protein), and latent TGF-beta-binding protein and incorporated latent TGF-beta 1 into their matrices as shown by immunoblotting. Amnion epithelial cells produced lower levels of these proteins. Confluent cultures of epithelial cells were exposed to matrix-degrading proteases and glycosidases. Mast cell chymase, leukocyte elastase, and plasmin efficiently released matrix-bound latent TGF-beta 1 complexes, while chondroitinase ABC and heparitinases were ineffective. The ability of the proteases to activate recombinant latent TGF-beta 1 was tested using growth inhibition assays and a novel sodium deoxycholate-polyacrylamide gel electrophoresis followed by immunoblotting. Sodium deoxycholate solubilized M(r) 25,000 TGF-beta 1 but did not dissociate high M(r) latent TGF-beta 1 complexes, allowing separation of these forms by polyacrylamide gel electrophoresis. Mast cell chymase and leukocyte elastase did not activate latent TGF-beta 1, suggesting that its release from matrix and activation are controlled by different mechanisms. The release of TGF-beta from the matrix by leukocyte and mast cell enzymes may contribute to the accumulation of connective tissue in inflammation.
authors.affiliation: Department of Virology, University of Helsinki, Finland.
authors.forename: J
authors.initials: J
authors.lastname: Taipale
authors.forename: J
authors.initials: J
authors.lastname: Lohi
authors.forename: J
authors.initials: J
authors.lastname: Saarinen
authors.forename: P T
authors.initials: PT
authors.lastname: Kovanen
authors.forename: J
authors.initials: J
authors.lastname: Keski-Oja
mesh_terms: D000650:Amnion / Q000378:metabolism; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D002478:Cells, Cultured; D053818:Chymases; D004727:Endothelium / Q000378:metabolism; D004848:Epithelium / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D053779:Latent TGF-beta Binding Proteins; D019272:Leukocyte Elastase; D008407:Mast Cells / Q000201:enzymology*; D008907:Mink; D010196:Pancreatic Elastase / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D012697:Serine Endopeptidases / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D053779:Latent TGF-beta Binding Proteins; D016212:Transforming Growth Factor beta; D012697:Serine Endopeptidases; D010196:Pancreatic Elastase; D019272:Leukocyte Elastase; D053818:Chymases