Battle of the kinases: Integration of adrenal responses to cAMP, DG and Ca2+at the level of steroidogenic cytochromes P450 and 3ßHSD expression in H295R cells.
- 1 January 1998
- journal article
- research article
- Published by Taylor & Francis Ltd in Endocrine Research
- Vol. 24 (3-4), 345-354
- https://doi.org/10.3109/07435809809032614
Abstract
While ACTH receptors (activating the protein kinase A pathway) are expressed throughout the human/bovine/ovine zona glomerulosa (zg) and zona fasciculata (zf), there are clear zonal differences in AII Type-1 receptor levels (activating protein kinase C/Ca2+), as well as resting membrane potential. Thus zg is most responsive to AII and K+ (Ca2+ signalling), while zf is less responsive to AII with no K+ response. Zonal function in turn requires differential expression of CYP17/3ßHSD and CYP11B2/CYP11B1. We have used the H295R cell to study how differential activation of kinase A, kinase C and Ca2+/calmodulin (CaM) kinases may alter the relative expression of the steroidogenic P450s and 3ßHSDII. While CYP11A, CYP17, 3ßHSDII, CYP21, and CYP11B1 are all induced by increases in cAMP, studies with TPA alone or in combination with forskolin reveal subsets of steroidogenic enzymes regulated either positively (CYP21, 3ßHSDII) or negatively (CYP17, CYP11A) by protein kinase C. Thus adrenal 3ßHSDII and CYP21 expression is high in zg and zf, but CYP17 is not expressed in the zg where AII activation of kinase C is highest. In turn both K+ and AII-induced elevation of Ca2+ strongly induces CYP11B2 but not CYP11B1, consistent with preferential expression of CYP11B2 in the zg. We conclude that differential signaling through kinase C and CaM kinases in addition to kinase A underlies zonal differences in both the early and late pathways involved in steroid hormone production within the adrenocortical zones.Keywords
This publication has 10 references indexed in Scilit:
- The Role of Cytochrome P450 17α-Hydroxylase and 3β-Hydroxysteroid Dehydrogenase in the Integration of Gonadal and Adrenal Steroidogenesis via the Δ5 and Δ4 Pathways of Steroidogenesis in MammalsBiology of Reproduction, 1997
- Ca2+-Regulated Expression of Aldosterone Synthase Is Mediated By Calmodulin and Calmodulin-Dependent Protein KinasesEndocrinology, 1997
- Immunohistochemical analysis of AT 1 receptor versus P450c17 and 3?HSD expression in ovine adrenals.Endocrine Research, 1996
- Adrenarche is associated with decreased 3β-hydroxysteroid dehydrogenase expression in the adrenal reticularisEndocrine Research, 1996
- Differential regulation of 11β-hydroxylase and aldosterone synthase in human adrenocortical H295R cellsMolecular and Cellular Endocrinology, 1996
- Adrenal Androgen Biosynthesis with Special Attention to P450c17Annals of the New York Academy of Sciences, 1995
- Ca(2+)-regulated expression of steroid hydroxylases in H295R human adrenocortical cells.Endocrinology, 1995
- Potassium Negatively Regulates Angiotensin II Type 1 Receptor Expression in Human Adrenocortical H295R CellsHypertension, 1995
- The NCI-H295 cell line: a pluripotent model for human adrenocortical studiesMolecular and Cellular Endocrinology, 1994
- The Cloning of a Family of Genes That Encode the Melanocortin ReceptorsScience, 1992