The human adrenal cortex is a complex endocrine gland that secrets mineralocorticoids and glucocorticoids. These steroids arise from morphologically and biochemically distinct zones of the adrenal cortex. The long range objective of the proposed research is to define the mechanisms that lead to and control zonation of the human adrenal. There is formidable evidence that aldosterone synthase (P450c18) concentrates in the zona glomerulosa and that zona fasciculata cells express 11beta- hydroxylase (P450c11), 17alpha-hydroxylase (P450c17), but no P450c18. The lack of an appropriate in vitro model system that maintains zona glomerulosa function has limited our understanding of the mechanisms controlling the zone-specific expression of these enzymes and their role in the norman and pathophysiology of the adrenal. We have overcome this obstacle by the development of a strain of NCI-H295 cells that will differentially express P450c18, P450c11, and P430c17 in a zone-specific manner. In addition, we have demonstrated that the H295 cells represent the first adrenocortical cell line which has maintained the ability to produce aldosterone and respond to angiotensin II. We will utilize these cells to define the biomolecular regulation of adrenal zonation.
In Specific Aim 1, the principal second messenger systems regulating zone- specific steroidogenesis and the expression of the mRNAs for P450c18, P450c11, and P450c17 will first be determined. Due to the centripetal nature of adrenocortical blood flow, the role of intra-adrenal factors (i. e., insulin-like growth factors, transforming growth factor betas and steroid hormones) in zone-specific steroidogenesis and expression of P450c18, P450c11, and P450c17 will also be determined. The zone-specific expression of steroidogenic enzymes is most likely due to regulation of gene transcription. Thus, the 5'-genetic regions responsible for the activation or inhibition of transcription of P450c18 and P450c17 will be determined in Specific Aim 2, using transfection assays of chimeric gene constructs into H295 cells. These experiments will help to determine the specific consensus sequences involved in the zone-specific expression of these enzymes. By way of preliminary studies, we find that AII is importance in the regulating the zone-specific production of steroids and differential expression of steroidogenic enzymes. The selected expression of the type 1 angiotensin II receptor (AT1-R) in the zona glomerulosa may be instrumental in causing zonation. Therefore, in Specific Aim 3, the endocrine and paracrine mechanisms regulating H295 cell expression of the AT1-R will be defined by monitoring angiotensin II binding and the level of AT1-R mRNA by northern analysis. Taken together the information gained from these studies will help define the fundamental mechanisms controlling zonation in the mammalian adrenal.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
1R29DK043140-01A3
Application #
2142796
Study Section
Endocrinology Study Section (END)
Project Start
1994-08-01
Project End
1999-07-31
Budget Start
1994-08-01
Budget End
1995-07-31
Support Year
1
Fiscal Year
1994
Total Cost
Indirect Cost
Name
University of Texas Sw Medical Center Dallas
Department
Obstetrics & Gynecology
Type
Schools of Medicine
DUNS #
City
Dallas
State
TX
Country
United States
Zip Code
75390
Nanba, Kazutaka; Chen, Andrew X; Omata, Kei et al. (2016) Molecular Heterogeneity in Aldosterone-Producing Adenomas. J Clin Endocrinol Metab 101:999-1007
Monticone, Silvia; Else, Tobias; Mulatero, Paolo et al. (2015) Understanding primary aldosteronism: impact of next generation sequencing and expression profiling. Mol Cell Endocrinol 399:311-20
Chen, Andrew X; Nishimoto, Koshiro; Nanba, Kazutaka et al. (2015) Potassium channels related to primary aldosteronism: Expression similarities and differences between human and rat adrenals. Mol Cell Endocrinol 417:141-8
Rege, Juilee; Nishimoto, Hiromi Koso; Nishimoto, Koshiro et al. (2015) Bone Morphogenetic Protein-4 (BMP4): A Paracrine Regulator of Human Adrenal C19 Steroid Synthesis. Endocrinology 156:2530-40
Nanba, Kazutaka; Chen, Andrew; Nishimoto, Koshiro et al. (2015) Role of Ca(2+)/calmodulin-dependent protein kinase kinase in adrenal aldosterone production. Endocrinology 156:1750-6
Nishimoto, Koshiro; Tomlins, Scott A; Kuick, Rork et al. (2015) Aldosterone-stimulating somatic gene mutations are common in normal adrenal glands. Proc Natl Acad Sci U S A 112:E4591-9
Nishimoto, Koshiro; Harris, Ruth B S; Rainey, William E et al. (2014) Sodium deficiency regulates rat adrenal zona glomerulosa gene expression. Endocrinology 155:1363-72
Nishimoto, Koshiro; Rainey, William E; Bollag, Wendy B et al. (2013) Lessons from the gene expression pattern of the rat zona glomerulosa. Mol Cell Endocrinol 371:107-13
Monticone, Silvia; Hattangady, Namita G; Penton, David et al. (2013) a Novel Y152C KCNJ5 mutation responsible for familial hyperaldosteronism type III. J Clin Endocrinol Metab 98:E1861-5
Wang, Tao; Rainey, William E (2012) Human adrenocortical carcinoma cell lines. Mol Cell Endocrinol 351:58-65

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