Thrombospondin: Synthesis and Secretion by Cells in Culture

• Published in: The Journal of cell biology Vol. 95; no. 1; pp. 351 - 354
• Main Authors: Raugi, Gregory J., Mumby, Susanne M., Abbott-Brown, Debbie, Bornstein, Paul
• Format: Journal Article
• Language: English
• Published: United States Rockefeller University Press 01.10.1982; The Rockefeller University Press
• Subjects: Animals; Antiserum; Aorta - metabolism; Cattle; Cell culture techniques; Cultured cells; Endothelial cells; Endothelium - metabolism; Fibroblasts; Fluorescence; Fluorescent Antibody Technique; Glycoproteins - biosynthesis; Glycoproteins - immunology; Glycoproteins - metabolism; Molecular Weight; Platelets; Rapid Communications; Smooth muscle myocytes; Thrombospondins; Ungulates
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.95.1.351

Thrombospondin, a high molecular weight glycoprotein secreted by platelets in response to activation by thrombin, has been identified by immunofluorescence in bovine aortic endothelial cells, human foreskin fibroblasts, and human aortic smooth muscle cells. Immunofluorescence patterns were found to be similar using antisera raised to thrombospondins purified either from bovine aortic endothelial cells or from human platelets. Radioimmune precipitation of pulse-labeled cellular proteins confirmed the presence of thrombospondin in positively stained cells. A sensitive quantitative enzyme-linked immunosorbent assay (ELISA) was developed and used to determine that the accumulation of secreted thrombospondin was similar for endothelial cells and fibroblasts but was higher for smooth muscle cells. The presence of thrombospondin in a variety of cells suggests that its function may not be limited to an involvement in platelet interactions.