Bovine chromaffin cells release a transforming growth factor-beta-like molecule contained within chromaffin granules.
Bovine chromaffin cells contain within their storage vesicles and release upon cholinergic stimulation a complex mixture of proteins and peptides. We present data suggesting that one of these proteins resembles transforming growth factor (TGF)-beta in terms of its biological activity. The assay used to assess the activity of TGF-beta is based on cells transfected with a plasminogen activator inhibitor-1 promoter-luciferase construct. The assay is highly specific in detecting TGF-beta 1, -beta 2, and -beta 3 but does not detect several cytokines and growth factors, such as fibroblast growth factor-2, transforming growth factor-alpha, platelet-derived growth factor-AB, insulin-like growth factor-1, or neurotrophin-3 or -4. Moreover, we show that this assay does not detect a wide range of TGF-beta superfamily members (activin A, bone morphogenetic protein-2, -4, -6, and -7, growth/differentiation factor-5, and glial cell line-derived neurotrophic factor). Chromaffin granules contain approximately 1 ng of TGF-beta/10 mg of protein. The biological activity elicited by the chromaffin granule component can be neutralized by using an antibody against TGF-beta 1/beta 2/beta 3. TGF-beta is releasable from cultured chromaffin cells stimulated with the cholinergic agonist carbachol (10(-5) M). These data suggest that TGF-beta is stored in chromaffin granules and can be released by exocytosis.
Krieglstein
K
K
Department of Anatomy and Cell Biology, University of Heidelberg, Germany.
Unsicker
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D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology; D002417:Cattle; D002837:Chromaffin Granules / Q000187:drug effects / Q000378:metabolism*; D016207:Cytokines / Q000494:pharmacology; D005089:Exocytosis; D006133:Growth Substances / Q000494:pharmacology; D008156:Luciferases / Q000235:genetics; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics; D011993:Recombinant Fusion Proteins; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000276:immunology / Q000378:metabolism*
D000906:Antibodies; D016207:Cytokines; D006133:Growth Substances; D017395:Plasminogen Activator Inhibitor 1; D011993:Recombinant Fusion Proteins; D016212:Transforming Growth Factor beta; D002217:Carbachol; D008156:Luciferases