Fibronectin, laminin, and collagen IV interact with ACTH and angiotensin II to dictate specific cell behavior and secretion in human fetal adrenal cells in culture

Whereas collagen IV is expressed throughout the fetal adrenal gland during the second trimester of human development, fibronectin, and laminin demonstrate a rather mirror-image distribution, with higher expression of fibronectin in the central portion and laminin at the periphery of the gland. In the present study, extracellular matrices were able to modulate the profile of steroid secretion in primary cultures: collagen IV favored cortisol secretion following adrenocorticotropin (ACTH) or angiotensin II (Ang II) stimulation while specific stimulation of the AT(2) receptor of Ang II elicited dehydroepiandrostenedione (DHEA) production. These effects were correlated by changes in mRNA levels of 3beta-hydroxysteroid dehydrojenase (3beta-HSD) and cytochrome P450C17. In contrast, fibronectin and laminin decreased cell responsiveness to ACTH in terms of cortisol secretion, but enhanced ACTH-stimulated androgen secretion. Finally, extracellular matrices were able to orchestrate cell behavior: collagen IV and laminin enhanced cell proliferation whereas fibronectin incited cell death. These results indicate that the nature of extracellular matrix coordinates specific steroidogenic pathways and cell turnover in the developing human fetal adrenal gland.