Cortisol overproduction results from DNA methylation of CYP11B1 in hypercortisolemia

Mitsuhiro Kometani,Koshiro Nishimoto,Hiroshi Koide,Tadayuki Akagi,Kuniaki Mukai,Takashi Yoneda,Masakazu Yamagishi,Isamu Miyamori,Takashi Yokota,Masashi Demura,Shigehiro Karashima,Shin-Ichi Horike,Yoshiyu Takeda,Celso E Gomez-Sanchez

doi:10.1038/s41598-017-11435-2

Abstract

Adrenocortical hormone excess, due to primary aldosteronism (PA) or hypercortisolemia, causes hypertension and cardiovascular complications. In PA, hypomethylation of aldosterone synthase (CYP11B2) is associated with aldosterone overproduction. However, in hypercortisolemia, the role of DNA methylation of 11β-hydroxylase (CYP11B1), which catalyzes cortisol biosynthesis and is highly homologous to CYP11B2, is unclear. The aims of our study were to determine whether the CYP11B1 expression was regulated through DNA methylation in hypercortisolemia with cortisol-producing adenoma (CPA), and to investigate a possible relationship between DNA methylation and somatic mutations identified in CPA. Methylation analysis showed that the CYP11B1 promoter was significantly less methylated in CPA than in adjacent unaffected adrenal tissue and white blood cells. Furthermore, in CPA with somatic mutations in either the catalytic subunit of protein kinase A (PRKACA) or the guanine nucleotide-binding protein subunit alpha (GNAS) gene, the CYP11B1 promoter was significantly hypomethylated. In addition, DNA methylation reduced CYP11B1 promoter activity using a reporter assay. Our study results suggest that DNA methylation at the CYP11B1 promoter plays a role in the regulation of CYP11B1 expression and cortisol production in CPA, and that somatic mutations associated with CPA reduce DNA methylation at the CYP11B1 promoter.

Highlights

Adrenocortical hormone excess, due to primary aldosteronism (PA) or hypercortisolemia, causes hypertension and cardiovascular complications
Exome sequencing revealed that cortisolproducing adenoma (CPA) frequently carry somatic mutations in the catalytic subunit of PKA (PRKACA) that leads to the activation of cyclic AMP (cAMP) response element-binding protein (CREB), and the guanine nucleotide-binding protein subunit alpha (GNAS) gene, resulting in an activation of PKA4, 5
We found that the CYP11B1 promoter in CPA is significantly hypomethylated compared to those in adjacent unaffected adrenal tissue (AUAT) and zona fasciculata (ZF)

Summary

Introduction

Adrenocortical hormone excess, due to primary aldosteronism (PA) or hypercortisolemia, causes hypertension and cardiovascular complications. In CPA with somatic mutations in either the catalytic subunit of protein kinase A (PRKACA) or the guanine nucleotide-binding protein subunit alpha (GNAS) gene, the CYP11B1 promoter was significantly hypomethylated. Exome sequencing revealed that CPAs frequently carry somatic mutations in the catalytic subunit of PKA (PRKACA) that leads to the activation of cAMP response element-binding protein (CREB), and the guanine nucleotide-binding protein subunit alpha (GNAS) gene, resulting in an activation of PKA4, 5. Both mutations result in increase of CYP11B1 expression and thereby an excessive production of cortisol. It is intriguing to focus on CPA that overexpresses CYP11B111, 12

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