scholarly journals Molecular mechanisms in primary aldosteronism

2019 ◽  
Vol 242 (3) ◽  
pp. R67-R79 ◽  
Author(s):  
Kelly De Sousa ◽  
Alaa B Abdellatif ◽  
Rami M El Zein ◽  
Maria-Christina Zennaro
Keyword(s):  
Arterial Hypertension ◽  
Adrenal Cortex ◽  
Primary Aldosteronism ◽  
Molecular Mechanisms ◽  
Somatic Mutations ◽  
Type I ◽  
Adrenal Hyperplasia ◽  
New Genes ◽  
Aldosterone Production ◽  
Bilateral Adrenal Hyperplasia

Primary aldosteronism (PA) is the most common form and an under-diagnosed cause of secondary arterial hypertension, accounting for up to 10% of hypertensive cases and associated to increased cardiovascular risk. PA is caused by autonomous overproduction of aldosterone by the adrenal cortex. It is mainly caused by a unilateral aldosterone-producing adenoma (APA) or bilateral adrenal hyperplasia. Excess aldosterone leads to arterial hypertension with suppressed renin, frequently associated to hypokalemia. Mutations in genes coding for ion channels and ATPases have been identified in APA, explaining the pathophysiology of increased aldosterone production. Different inherited genetic abnormalities led to the distinction of four forms of familial hyperaldosteronism (type I to IV) and other genetic defects very likely remain to be identified. Somatic mutations are identified in APA, but also in aldosterone-producing cell clusters (APCCs) in normal adrenals, in image-negative unilateral hyperplasia, in transitional lesions and in APCC from adrenals with bilateral adrenal hyperplasia (BAH). Whether these structures are precursors of APA or whether somatic mutations occur in a proliferative adrenal cortex, is still a matter of debate. This review will summarize our knowledge on the molecular mechanisms responsible for PA and the recent discovery of new genes related to early-onset and familial forms of the disease. We will also address new issues concerning genomic and proteomic changes in adrenals with APA and discuss adrenal pathophysiology in relation to aldosterone-producing structures in the adrenal cortex.

scholarly journals Progress on Genetic Basis of Primary Aldosteronism

Biomedicines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1708
Author(s):  
Izabela Karwacka ◽  
Łukasz Obołończyk ◽  
Sonia Kaniuka-Jakubowska ◽  
Michał Bohdan ◽  
Krzysztof Sworczak
Keyword(s):  
Primary Aldosteronism ◽  
Genetic Basis ◽  
Molecular Mechanisms ◽  
Genetic Disorders ◽  
Plasma Renin ◽  
Cardiovascular Complications ◽  
High Rate ◽  
Type I ◽  
Familial Hyperaldosteronism ◽  
Bilateral Adrenal Hyperplasia

Primary aldosteronism (PA) is a heterogeneous group of disorders caused by the autonomous overproduction of aldosterone with simultaneous suppression of plasma renin activity (PRA). It is considered to be the most common endocrine cause of secondary arterial hypertension (HT) and is associated with a high rate of cardiovascular complications. PA is most often caused by a bilateral adrenal hyperplasia (BAH) or aldosterone-producing adenoma (APA); rarer causes of PA include genetic disorders of steroidogenesis (familial hyperaldosteronism (FA) type I, II, III and IV), aldosterone-producing adrenocortical carcinoma, and ectopic aldosterone-producing tumors. Over the last few years, significant progress has been made towards understanding the genetic basis of PA, classifying it as a channelopathy. Recently, a growing body of clinical evidence suggests that mutations in ion channels appear to be the major cause of aldosterone-producing adenomas, and several mutations within the ion channel encoding genes have been identified. Somatic mutations in four genes (KCNJ5, ATP1A1, ATP2B3 and CACNA1D) have been identified in nearly 60% of the sporadic APAs, while germline mutations in KCNJ5 and CACNA1H have been reported in different subtypes of familial hyperaldosteronism. These new insights into the molecular mechanisms underlying PA may be associated with potential implications for diagnosis and therapy.

scholarly journals GENETICS IN ENDOCRINOLOGY: The expanding genetic horizon of primary aldosteronism

2018 ◽  
Vol 178 (3) ◽  
pp. R101-R111 ◽  
Author(s):  
Silvia Monticone ◽  
Fabrizio Buffolo ◽  
Martina Tetti ◽  
Franco Veglio ◽  
Barbara Pasini ◽  
...  
Keyword(s):  
Primary Aldosteronism ◽  
Molecular Mechanisms ◽  
Ion Homeostasis ◽  
Germline Mutations ◽  
Genetic Horizon ◽  
Electrolyte Homeostasis ◽  
Bilateral Adrenal Hyperplasia ◽  
Aldosterone Producing Adenoma ◽  
Mineralocorticoid Hormone ◽  
Generation Sequencing

Aldosterone is the main mineralocorticoid hormone in humans and plays a key role in maintaining water and electrolyte homeostasis. Primary aldosteronism (PA), characterized by autonomous aldosterone overproduction by the adrenal glands, affects 6% of the general hypertensive population and can be either sporadic or familial. Aldosterone-producing adenoma (APA) and bilateral adrenal hyperplasia (BAH) are the two most frequent subtypes of sporadic PA and 4 forms of familial hyperaldosteronism (FH-I to FH-IV) have been identified. Over the last six years, the introduction of next-generation sequencing has significantly improved our understanding of the molecular mechanisms responsible for autonomous aldosterone overproduction in both sporadic and familial PA. Somatic mutations in four genes (KCNJ5, ATP1A1, ATP2B3 and CACNA1D), differently implicated in intracellular ion homeostasis, have been identified in nearly 60% of the sporadic APAs. Germline mutations in KCNJ5 and CACNA1H cause FH-III and FH-IV, respectively, while germline mutations in CACNA1D cause the rare PASNA syndrome, featuring primary aldosteronism seizures and neurological abnormalities. Further studies are warranted to identify the molecular mechanisms underlying BAH and FH-II, the most common forms of sporadic and familial PA whose molecular basis is yet to be uncovered.

scholarly journals GRK2-Mediated Crosstalk Between β-Adrenergic and Angiotensin II Receptors Enhances Adrenocortical Aldosterone Production In Vitro and In Vivo

2020 ◽  
Vol 21 (2) ◽  
pp. 574
Author(s):  
Celina M. Pollard ◽  
Jennifer Ghandour ◽  
Natalie Cora ◽  
Arianna Perez ◽  
Barbara M. Parker ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
G Protein ◽  
Adrenal Cortex ◽  
Zona Glomerulosa ◽  
Type I ◽  
Signaling Crosstalk ◽  
Aldosterone Production ◽  
Steroidogenic Acute Regulatory

Aldosterone is produced by adrenocortical zona glomerulosa (AZG) cells in response to angiotensin II (AngII) acting through its type I receptors (AT1Rs). AT1R is a G protein-coupled receptor (GPCR) that induces aldosterone via both G proteins and the adapter protein βarrestin1, which binds the receptor following its phosphorylation by GPCR-kinases (GRKs) to initiate G protein-independent signaling. β-adrenergic receptors (ARs) also induce aldosterone production in AZG cells. Herein, we investigated whether GRK2 or GRK5, the two major adrenal GRKs, is involved in the catecholaminergic regulation of AngII-dependent aldosterone production. In human AZG (H295R) cells in vitro, the βAR agonist isoproterenol significantly augmented both AngII-dependent aldosterone secretion and synthesis, as measured by the steroidogenic acute regulatory (StAR) protein and CYP11B2 (aldosterone synthase) mRNA inductions. Importantly, GRK2, but not GRK5, was indispensable for the βAR-mediated enhancement of aldosterone in response to AngII. Specifically, GRK2 inhibition with Cmpd101 abolished isoproterenol’s effects on AngII-induced aldosterone synthesis/secretion, whereas the GRK5 knockout via CRISPR/Cas9 had no effect. It is worth noting that these findings were confirmed in vivo, since rats overexpressing GRK2, but not GRK5, in their adrenals had elevated circulating aldosterone levels compared to the control animals. However, treatment with the β-blocker propranolol prevented hyperaldosteronism in the adrenal GRK2-overexpressing rats. In conclusion, GRK2 mediates a βAR-AT1R signaling crosstalk in the adrenal cortex leading to elevated aldosterone production. This suggests that adrenal GRK2 may be a molecular link connecting the sympathetic nervous and renin-angiotensin systems at the level of the adrenal cortex and that its inhibition might be therapeutically advantageous in hyperaldosteronism-related conditions.

scholarly journals PRKACA Somatic Mutations Are Rare Findings in Aldosterone-Producing Adenomas

2016 ◽  
Vol 101 (8) ◽  
pp. 3010-3017 ◽  
Author(s):  
Yara Rhayem ◽  
Luis G. Perez-Rivas ◽  
Anna Dietz ◽  
Kerstin Bathon ◽  
Christian Gebhard ◽  
...  
Keyword(s):  
Cushing’S Syndrome ◽  
Primary Aldosteronism ◽  
Molecular Mechanisms ◽  
Somatic Mutations ◽  
Functional Characterization ◽  
Cushing's Syndrome ◽  
Antihypertensive Medications ◽  
Unilateral Adrenalectomy ◽  
Vitro Analysis

Context: Somatic mutations have been found causative for endocrine autonomy in aldosterone-producing adenomas (APAs). Whereas mutations of PRKACA (catalytic subunit of protein kinase A) have been identified in cortisol-producing adenomas, the presence of PRKACA variants in APAs is unknown, especially in those that display cosecretion of cortisol. Objective: The objective of the study was to investigate PRKACA somatic variants identified in APA cases. Design: Identification of PRKACA somatic variants in APAs by whole-exome sequencing followed by in vitro analysis of the enzymatic activity of PRKACA variants and functional characterization by double immunofluorescence of CYP11B2 and CYP11B1 expression in the corresponding tumor tissues. Setting and Patients: APA tissues were collected from 122 patients who underwent unilateral adrenalectomy for primary aldosteronism between 2005 and 2015 at a single institution. Results: PRKACA somatic mutations were identified in two APA cases (1.6%). One APA carried a newly identified p.His88Asp variant, whereas in a second case, a p.Leu206Arg mutation was found, previously described only in cortisol-producing adenomas with overt Cushing's syndrome. Functional analysis showed that the p.His88Asp variant was not associated with gain of function. Although CYP11B2 was strongly expressed in the p.His88Asp-mutated APA, the p.Leu206Arg carrying APA predominantly expressed CYP11B1. Accordingly, biochemical Cushing's syndrome was present only in the patient with the p.Leu206Arg mutation. After adrenalectomy, both patients improved with a reduced number of antihypertensive medications and normalized serum potassium levels. Conclusions: We describe for the first time PRKACA mutations as rare findings associated with unilateral primary aldosteronism. As cortisol cosecretion occurs in a subgroup of APAs, other molecular mechanisms are likely to exist.

scholarly journals A Case of Primary Aldosteronism due to Bilateral Adrenal Hyperplasia with Hidden Undiagnosed Adrenal Adenoma for Eight Years

1996 ◽  
Vol 19 (1) ◽  
pp. 47
Author(s):  
Seock Ah Im ◽  
Eun Mi Nam ◽  
Si Hoon Park ◽  
Gil Ja Shin ◽  
Woo Hyung Lee ◽  
...  
Keyword(s):  
Primary Aldosteronism ◽  
Adrenal Adenoma ◽  
Adrenal Hyperplasia ◽  
Bilateral Adrenal Hyperplasia

scholarly journals Angiotensin II Type 1 Receptor Autoantibodies in Primary Aldosteronism

2020 ◽  
Vol 52 (06) ◽  
pp. 379-385
Author(s):  
Lucie S. Meyer ◽  
Siyuan Gong ◽  
Martin Reincke ◽  
Tracy Ann Williams
Keyword(s):  
Angiotensin Ii ◽  
Primary Aldosteronism ◽  
Functional Role ◽  
Adrenal Hyperplasia ◽  
Endocrine Hypertension ◽  
Bilateral Adrenal Hyperplasia ◽  
Aldosterone Producing Adenoma ◽  
Agonistic Autoantibodies

AbstractPrimary aldosteronism (PA) is the most common form of endocrine hypertension. Agonistic autoantibodies against the angiotensin II type 1 receptor (AT1R-Abs) have been described in transplantation medicine and women with pre-eclampsia and more recently in patients with PA. Any functional role of AT1R-Abs in either of the two main subtypes of PA (aldosterone-producing adenoma or bilateral adrenal hyperplasia) requires clarification. In this review, we discuss the studies performed to date on AT1R-Abs in PA.

scholarly journals Analysis of Unilateral Adrenal Hyperplasia with Primary Aldosteronism from the Aspect of Messenger Ribonucleic Acid Expression for Steroidogenic Enzymes: A Comparative Study with Adrenal Cortices Adhering to Aldosterone-Producing Adenoma

Endocrinology ◽  
2006 ◽  
Vol 147 (2) ◽  
pp. 999-1006 ◽  
Author(s):  
Kazuto Shigematsu ◽  
Kioko Kawai ◽  
Junji Irie ◽  
Hideki Sakai ◽  
Osamu Nakashima ◽  
...  
Keyword(s):  
Primary Aldosteronism ◽  
Zona Glomerulosa ◽  
Adrenal Hyperplasia ◽  
Steroidogenic Enzymes ◽  
Unilateral Adrenalectomy ◽  
Messenger Ribonucleic Acid ◽  
Unilateral Adrenal Hyperplasia ◽  
Aldosterone Production ◽  
Long Term Follow Up ◽  
Aldosterone Producing Adenoma

Unilateral adrenal hyperplasia with primary aldosteronism is very rare and shows similar endocrine features to aldosterone-producing adenoma and bilateral adrenal hyperplasia. In this study, the mRNA expression of steroidogenic enzymes in unilateral adrenal hyperplasia was examined by in situ hybridization. We found subcapsular micronodules composed of spironolactone body-containing cells, which showed intense expression for 3β-hydroxysteroid dehydrogenase, 11β-hydroxylase, 18-hydroxylase, and 21-hydroxylase but not 17α-hydroxylase, indicating aldosterone production. This expression pattern was the same as that in unilateral multiple adrenocortical micronodules, reported recently. Additionally, it was noted that a nodule with active aldosterone production was closely adjacent to one showing intense 17α-hydroxylase expression. In the adrenal cortices adhering to aldosterone-producing adenoma, the majority of hyperplastic zona glomerulosa and hyperplastic nodules demonstrated a decreased steroidogenic activity. However, minute nodules indicative of active aldosterone production were found at high frequency. These results suggest that the subcapsular micronodules observed might be the root of aldosterone-producing adenoma. Furthermore, we emphasize the need for long-term follow-up after unilateral adrenalectomy or enucleation of the adenoma because of the possibility that buds with autonomous aldosterone production may still be present in the contralateral or remaining adrenal tissue.

scholarly journals Mouse Models of Primary Aldosteronism: From Physiology to Pathophysiology

Endocrinology ◽  
2017 ◽  
Vol 158 (12) ◽  
pp. 4129-4138 ◽  
Author(s):  
Leticia Aragao-Santiago ◽  
Celso E Gomez-Sanchez ◽  
Paolo Mulatero ◽  
Ariadni Spyroglou ◽  
Martin Reincke ◽  
...  
Keyword(s):  
Mouse Models ◽  
Primary Aldosteronism ◽  
Genetic Basis ◽  
Plasma Renin ◽  
Adrenal Hyperplasia ◽  
Endocrine Hypertension ◽  
Bilateral Adrenal Hyperplasia ◽  
Human Disorder ◽  
Aldosterone Producing Adenoma ◽  
Functional Mechanisms

Abstract Primary aldosteronism (PA) is a common form of endocrine hypertension that is characterized by the excessive production of aldosterone relative to suppressed plasma renin levels. PA is usually caused by either a unilateral aldosterone-producing adenoma or bilateral adrenal hyperplasia. Somatic mutations have been identified in several genes that encode ion pumps and channels that may explain the aldosterone excess in over half of aldosterone-producing adenomas, whereas the pathophysiology of bilateral adrenal hyperplasia is largely unknown. A number of mouse models of hyperaldosteronism have been described that recreate some features of the human disorder, although none replicate the genetic basis of human PA. Animal models that reproduce the genotype–phenotype associations of human PA are required to establish the functional mechanisms that underlie the endocrine autonomy and deregulated cell growth of the affected adrenal and for preclinical studies of novel therapeutics. Herein, we discuss the differences in adrenal physiology across species and describe the genetically modified mouse models of PA that have been developed to date.

scholarly journals Mass Spectrometry–Based Adrenal and Peripheral Venous Steroid Profiling for Subtyping Primary Aldosteronism

2016 ◽  
Vol 62 (3) ◽  
pp. 514-524 ◽  
Author(s):  
Graeme Eisenhofer ◽  
Tanja Dekkers ◽  
Mirko Peitzsch ◽  
Anna S Dietz ◽  
Martin Bidlingmaier ◽  
...  
Keyword(s):  
Primary Aldosteronism ◽  
Plasma Concentrations ◽  
Adrenal Hyperplasia ◽  
Peripheral Plasma ◽  
Steroid Profiling ◽  
Bilateral Adrenal Hyperplasia ◽  
Potential Use ◽  
Venous Plasma

Abstract BACKGROUND Differentiating patients with primary aldosteronism caused by aldosterone-producing adenomas (APAs) from those with bilateral adrenal hyperplasia (BAH), which is essential for choice of therapeutic intervention, relies on adrenal venous sampling (AVS)-based measurements of aldosterone and cortisol. We assessed the utility of LC-MS/MS–based steroid profiling to stratify patients with primary aldosteronism. METHODS Fifteen adrenal steroids were measured by LC-MS/MS in peripheral and adrenal venous plasma from AVS studies for 216 patients with primary aldosteronism at 3 tertiary referral centers. Ninety patients were diagnosed with BAH and 126 with APAs on the basis of immunoassay-derived adrenal venous aldosterone lateralization ratios. RESULTS Among 119 patients confirmed to have APAs at follow-up, LC-MS/MS–derived lateralization ratios of aldosterone normalized to cortisol, dehydroepiandrosterone, and androstenedione were all higher (P < 0.0001) than immunoassay-derived ratios. The hybrid steroids, 18-oxocortisol and 18-hydroxycortisol, also showed lateralized secretion in 76% and 35% of patients with APAs. Adrenal venous concentrations of glucocorticoids and androgens were bilaterally higher in patients with BAH than in those with APAs. Consequently, peripheral plasma concentrations of 18-oxocortisol were 8.5-fold higher, whereas concentrations of cortisol, corticosterone, and dehydroepiandrosterone were lower in patients with APAs than in those with BAH. Correct classification of 80% of cases of APAs vs BAH was thereby possible by use of a combination of steroids in peripheral plasma. CONCLUSIONS LC-MS/MS–based steroid profiling during AVS achieves higher aldosterone lateralization ratios in patients with APAs than immunoassay. LC-MS/MS also enables multiple measures for discriminating unilateral from bilateral aldosterone excess, with potential use of peripheral plasma for subtype classification.

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