Chemogenetic activation of adrenocortical Gq signaling causes hyperaldosteronism and disrupts functional zonation
Matthew J. Taylor, … , David T. Breault, William E. Rainey
Matthew J. Taylor, … , David T. Breault, William E. Rainey
Published November 18, 2019
Citation Information: J Clin Invest. 2020;130(1):83-93. https://doi.org/10.1172/JCI127429.
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Research Article Endocrinology

Chemogenetic activation of adrenocortical Gq signaling causes hyperaldosteronism and disrupts functional zonation

Abstract

The mineralocorticoid aldosterone is produced in the adrenal zona glomerulosa (ZG) under the control of the renin–angiotensin II (AngII) system. Primary aldosteronism (PA) results from renin-independent production of aldosterone and is a common cause of hypertension. PA is caused by dysregulated localization of the enzyme aldosterone synthase (Cyp11b2), which is normally restricted to the ZG. Cyp11b2 transcription and aldosterone production are predominantly regulated by AngII activation of the Gq signaling pathway. Here, we report the generation of transgenic mice with Gq-coupled designer receptors exclusively activated by designer drugs (DREADDs) specifically in the adrenal cortex. We show that adrenal-wide ligand activation of Gq DREADD receptors triggered disorganization of adrenal functional zonation, with induction of Cyp11b2 in glucocorticoid-producing zona fasciculata cells. This result was consistent with increased renin-independent aldosterone production and hypertension. All parameters were reversible following termination of DREADD-mediated Gq signaling. These findings demonstrate that Gq signaling is sufficient for adrenocortical aldosterone production and implicate this pathway in the determination of zone-specific steroid production within the adrenal cortex. This transgenic mouse also provides an inducible and reversible model of hyperaldosteronism to investigate PA therapeutics and the mechanisms leading to the damaging effects of aldosterone on the cardiovascular system.

Authors

Matthew J. Taylor, Matthew R. Ullenbruch, Emily C. Frucci, Juilee Rege, Mark S. Ansorge, Celso E. Gomez-Sanchez, Salma Begum, Edward Laufer, David T. Breault, William E. Rainey

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Figure 2

CNO activation of adrenal hM3Dq upregulates Cyp11b2 expression and aldosterone production.

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CNO activation of adrenal hM3Dq upregulates Cyp11b2 expression and aldos...
(A) Experimental protocol. AS+/Cre hM3Dq female 18- to 20-week-old mice were treated with CNO (50 μg/mL) or vehicle in their drinking water (ad libitum) for 7 days prior to sacrifice. (B) Mouse adrenal steroidogenic pathway. Star transports cholesterol to the inner mitochondrial membrane, where it is converted to pregnenolone prior to downstream conversion to either glucocorticoids (ZF) or mineralocorticoids (ZG) by steroidogenic enzymes. (C) qPCR analysis of steroidogenic enzyme mRNA in whole adrenal tissue. n = 8 for both groups for steroidogenic enzymes; n = 10 for Cyp11b1 and Cyp11b2 (vehicle treatment); n = 11 for Cyp11b1 and Cyp11b2 (CNO treatment). (D) Immunofluorescence staining for Cyp11b2 and Cyp11b1. Scale bars: 50 μm. (E) Steroid levels were measured by LC-MS/MS. n = 13 for vehicle treatment; n = 17 for CNO treatment. (F) qPCR analysis of kidney Ren1. n = 6 for vehicle treatment; n = 5 for CNO treatment. (G) Plasma renin concentrations. n = 11 for vehicle treatment; n = 13 for CNO treatment. Data in the dot plots represent the mean ± SEM. *P < 0.05 and **P < 0.01, by unpaired, 2-tailed Student’s t test. Veh, vehicle.