title: Aldosterone-stimulating somatic gene mutations are common in normal adrenal glands.
abstract: Primary aldosteronism (PA) represents the most common cause of secondary hypertension, but little is known regarding its adrenal cellular origins. Recently, aldosterone-producing cell clusters (APCCs) with high expression of aldosterone synthase (CYP11B2) were found in both normal and PA adrenal tissue. PA-causing aldosterone-producing adenomas (APAs) harbor mutations in genes encoding ion channels/pumps that alter intracellular calcium homeostasis and cause renin-independent aldosterone production through increased CYP11B2 expression. Herein, we hypothesized that APCCs have APA-related aldosterone-stimulating somatic gene mutations. APCCs were studied in 42 normal adrenals from kidney donors. To clarify APCC molecular characteristics, we used microarrays to compare the APCC transcriptome with conventional adrenocortical zones [zona glomerulosa (ZG), zona fasciculata, and zona reticularis]. The APCC transcriptome was most similar to ZG but with an enhanced capacity to produce aldosterone. To determine if APCCs harbored APA-related mutations, we performed targeted next generation sequencing of DNA from 23 APCCs and adjacent normal adrenal tissue isolated from both formalin-fixed, paraffin-embedded, and frozen tissues. Known aldosterone driver mutations were identified in 8 of 23 (35%) APCCs, including mutations in calcium channel, voltage-dependent, L-type, α1D-subunit (CACNA1D; 6 of 23 APCCs) and ATPase, Na(+)/(K+) transporting, α1-polypeptide (ATP1A1; 2 of 23 APCCs), which were not observed in the adjacent normal adrenal tissue. Overall, we show three major findings: (i) APCCs are common in normal adrenals, (ii) APCCs harbor somatic mutations known to cause excess aldosterone production, and (iii) the mutation spectrum of aldosterone-driving mutations is different in APCCs from that seen in APA. These results provide molecular support for APCC as a precursor of PA.
authors.affiliation: Departments of Molecular and Integrative Physiology and Internal Medicine, University of Michigan, Ann Arbor, MI 48109;
authors.forename: Koshiro
authors.initials: K
authors.lastname: Nishimoto
authors.affiliation: Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI 48109; Department of Pathology, University of Michigan, Ann Arbor, MI 48109; Deparment of Urology, University of Michigan, Ann Arbor, MI 48109; Comprehensive Cancer Center, University of Michigan, Ann Arbor, MI 48109;
authors.forename: Scott A
authors.initials: SA
authors.lastname: Tomlins
authors.affiliation: Department of Biostatistics, University of Michigan, Ann Arbor, MI 48109;
authors.forename: Rork
authors.initials: R
authors.lastname: Kuick
authors.affiliation: Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI 48109; Department of Pathology, University of Michigan, Ann Arbor, MI 48109;
authors.forename: Andi K
authors.initials: AK
authors.lastname: Cani
authors.affiliation: Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI 48109; Department of Pathology, University of Michigan, Ann Arbor, MI 48109;
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Giordano
authors.affiliation: Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI 48109; Department of Pathology, University of Michigan, Ann Arbor, MI 48109; Department of Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, MI 48109;
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Hovelson
authors.affiliation: Michigan Center for Translational Pathology, University of Michigan, Ann Arbor, MI 48109; Department of Pathology, University of Michigan, Ann Arbor, MI 48109;
authors.forename: Chia-Jen
authors.initials: CJ
authors.lastname: Liu
authors.affiliation: Departments of Molecular and Integrative Physiology and Internal Medicine, University of Michigan, Ann Arbor, MI 48109;
authors.forename: Aalok R
authors.initials: AR
authors.lastname: Sanjanwala
authors.affiliation: Department of Surgery, Temple University School of Medicine, Philadelphia, PA 19140;
authors.forename: Michael A
authors.initials: MA
authors.lastname: Edwards
authors.affiliation: Division of Endocrinology, G. V. (Sonny) Montgomery Veterans Affairs Medical Center and University of Mississippi Medical Center, Jackson, MS 39110.
authors.forename: Celso E
authors.initials: CE
authors.lastname: Gomez-Sanchez
authors.affiliation: Departments of Molecular and Integrative Physiology and Internal Medicine, University of Michigan, Ann Arbor, MI 48109;
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Nanba
authors.affiliation: Departments of Molecular and Integrative Physiology and Internal Medicine, University of Michigan, Ann Arbor, MI 48109; wer@umich.edu.
authors.forename: William E
authors.initials: WE
authors.lastname: Rainey
mesh_terms: D000302:Adrenal Cortex / Q000378:metabolism; D000311:Adrenal Glands / Q000378:metabolism*; D000450:Aldosterone / Q000096:biosynthesis*; D019405:Cytochrome P-450 CYP11B2 / Q000378:metabolism; D004247:DNA / Q000737:chemistry; D005786:Gene Expression Regulation; D059014:High-Throughput Nucleotide Sequencing; D006706:Homeostasis; D006801:Humans; D006929:Hyperaldosteronism / Q000209:etiology; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D025341:Principal Component Analysis; D017422:Sequence Analysis, DNA; D017423:Sequence Analysis, RNA; D059467:Transcriptome; D015384:Zona Glomerulosa
chemical_list: D000450:Aldosterone; D004247:DNA; D019405:Cytochrome P-450 CYP11B2
keywords: adrenal; aldosterone; aldosterone-producing cell cluster; primary aldosteronism; somatic mutations