Bovine adrenocortical cells exhibit high affinity transforming growth factor-beta receptors which are regulated by adrenocorticotropin

• Published in: The Journal of biological chemistry Vol. 263; no. 12; pp. 5707 - 5713
• Main Authors: Cochet, C, Feige, J J, Chambaz, E M
• Format: Journal Article
• Language: English
• Published: Bethesda, MD Elsevier Inc 25.04.1988; American Society for Biochemistry and Molecular Biology
• Subjects: adrenal cortex; Adrenal Cortex - metabolism; adrenocorticotropic hormone; Adrenocorticotropic Hormone - pharmacology; Animals; Biological and medical sciences; Bucladesine - pharmacology; Cattle; Cell physiology; Cells, Cultured; Colforsin - pharmacology; Cross-Linking Reagents; Cyclic AMP - biosynthesis; Dose-Response Relationship, Drug; Fundamental and applied biological sciences. Psychology; Growth Substances - pharmacology; Hormonal regulation; Humans; Kinetics; Male; Mice; Molecular and cellular biology; Peptides - metabolism; Receptors, Cell Surface - drug effects; Receptors, Cell Surface - metabolism; Receptors, Transforming Growth Factor beta; Succinimides; transforming growth factor- beta; Transforming Growth Factors; Cell culture; Bovine; Adrenal glands; Transforming growth factor; Adrenal cortex; ACTH; Vertebrata; Membrane receptor; Mammalia; Animal; Hormonal regulation; Artiodactyla; Ungulata
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)60623-4

Transforming growth factor beta (TGF-beta) at picomolar concentrations has been previously shown to induce striking alterations of bovine adrenocortical cell differentiated functions, without detectable effect on growth activity (Feige, J.J., Cochet, C., and Chambaz, E. M. (1986) Biochem. Biophys. Res. Commun. 139, 693-700; Hotta, M., and Baird, A. (1986) Proc. Natl. Acad. Sci. U. S. A. 83, 7795-7799). Adrenocortical cells in culture could bind 125I-labeled TGF-beta through at least two different binding systems. The highest affinity TGF-beta binding exhibited a Kd value of 5.7 X 10(-10) M and a calculated capacity of about 100,000 sites/cell, while the low affinity system yielded values of 4.3 X 10(-8) M and 2 X 10(6) sites/cell, respectively. The 125I-labeled TGF-beta bound to adrenocortical cells could be cross-linked using disuccinimidyl suberate and subsequent electrophoretic analysis revealed that TGF-beta was associated with two major cell components of about 280 kDa and 70-75 kDa, respectively, the latter one being resolved as a labeled doublet. Thus bovine adrenocortical cells exhibit a TGF-beta receptor similar to that defined by Massagué and co-workers (Cheifetz, S., Like, B., and Massagué, J. (1986) J. Biol. Chem. 261,9972-9978) in other cell types. Various growth factors, including fibroblast growth factor, as well as established hormonal activators of adrenocortical cell differentiated functions, such as angiotensin II and adrenocorticotropin, were examined as to their effect on TGF-beta receptor activity. A striking increase in the number of high affinity TGF-beta receptors was selectively elicited by ACTH in the nanomolar concentration range. This effect was time- and dose-dependent and was mimicked by cell treatment with dibutyryl cyclic AMP or forskolin. However, the ACTH-induced increase in receptor number was not impaired when protein synthesis was blocked. It is concluded that bovine adrenocortical cells are typical target cells for TGF-beta. This endocrine system represents a model in which, for the first time, the level of TGF-beta receptor is shown to be under hormonal regulation through a cyclic AMP-dependent pathway.