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MacKenzie SM, van Kralingen JC, Davies E. Regulation of Aldosterone Secretion. VITAMINS AND HORMONES 2018; 109:241-263. [PMID: 30678858 DOI: 10.1016/bs.vh.2018.07.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Secretion of the major mineralocorticoid aldosterone from the adrenal cortex is a tightly-regulated process enabling this hormone to regulate sodium homeostasis and thereby contribute to blood pressure control. The circulating level of aldosterone is the result of various regulatory mechanisms, the most significant being those controlled by the renin-angiotensin system and plasma potassium levels. The importance of maintaining tight control over aldosterone secretion is demonstrated by cases of dysregulation, which can result in severe hypertension and significantly increased cardiovascular risk. In this article we summarize current knowledge of the major regulatory mechanisms, focusing particularly on the systems operating within the adrenocortical zona glomerulosa cells; we also describe some of the other factors that influence aldosterone production to a lesser but still significant extent. Finally, we discuss the influence of common genetic polymorphisms on aldosterone secretion in large sections of the population and also the emerging role of microRNA as significant regulators of this system.
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Affiliation(s)
- Scott M MacKenzie
- BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Josie C van Kralingen
- BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Eleanor Davies
- BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
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Fujihara CK, Kowala MC, Breyer MD, Sena CR, Rodrigues MV, Arias SCA, Fanelli C, Malheiros DM, Jadhav PK, Montrose-Rafizadeh C, Krieger JE, Zatz R. A Novel Aldosterone Antagonist Limits Renal Injury in 5/6 Nephrectomy. Sci Rep 2017; 7:7899. [PMID: 28801620 PMCID: PMC5554220 DOI: 10.1038/s41598-017-08383-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 07/12/2017] [Indexed: 01/13/2023] Open
Abstract
Aldosterone antagonists slow the progression of chronic kidney disease (CKD), but their use is limited by hyperkalemia, especially when associated with RAS inhibitors. We examined the renoprotective effects of Ly, a novel non-steroidal mineralocorticoid receptor (MR) blocker, through two experimental protocols: In Protocol 1, male Munich-Wistar rats underwent 5/6 renal ablation (Nx), being divided into: Nx+V, receiving vehicle, Nx+Eple, given eplerenone, 150 mg/kg/day, and Nx+Ly, given Ly, 20 mg/kg/day. A group of untreated sham-operated rats was also studied. Ly markedly raised plasma renin activity (PRA) and aldosterone, and exerted more effective anti-albuminuric and renoprotective action than eplerenone. In Protocol 2, Nx rats remained untreated until Day 60, when they were divided into: Nx+V receiving vehicle; Nx+L treated with losartan, 50 mg/kg/day; Nx+L+Eple, given losartan and eplerenone, and Nx+L+Ly, given losartan and Ly. Treatments lasted for 90 days. As an add-on to losartan, Ly normalized blood pressure and albuminuria, and prevented CKD progression more effectively than eplerenone. This effect was associated with strong stimulation of PRA and aldosterone. Despite exhibiting higher affinity for the MR than either eplerenone or spironolactone, Ly caused no hyperkalemia. Ly may become a novel asset in the effort to detain the progression of CKD.
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Affiliation(s)
| | - M C Kowala
- Lilly Research Laboratories, Indianapolis, IN, USA
| | - M D Breyer
- Lilly Research Laboratories, Indianapolis, IN, USA
| | - Claudia R Sena
- Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | | | | | - Camilla Fanelli
- Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | | | - P K Jadhav
- Lilly Research Laboratories, Indianapolis, IN, USA
| | | | - Jose E Krieger
- Faculty of Medicine, University of São Paulo, São Paulo, Brazil
| | - Roberto Zatz
- Faculty of Medicine, University of São Paulo, São Paulo, Brazil.
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Fülöp L, Rajki A, Katona D, Szanda G, Spät A. Extramitochondrial OPA1 and adrenocortical function. Mol Cell Endocrinol 2013; 381:70-9. [PMID: 23906536 DOI: 10.1016/j.mce.2013.07.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 07/19/2013] [Accepted: 07/19/2013] [Indexed: 02/06/2023]
Abstract
We have previously described that silencing of the mitochondrial protein OPA1 enhances mitochondrial Ca(2+) signaling and aldosterone production in H295R adrenocortical cells. Since extramitochondrial OPA1 (emOPA1) was reported to facilitate cAMP-induced lipolysis, we hypothesized that emOPA1, via the enhanced hydrolysis of cholesterol esters, augments aldosterone production in H295R cells. A few OPA1 immunopositive spots were detected in ∼40% of the cells. In cell fractionation studies OPA1/COX IV (mitochondrial marker) ratio in the post-mitochondrial fractions was an order of magnitude higher than that in the mitochondrial fraction. The ratio of long to short OPA1 isoforms was lower in post-mitochondrial than in mitochondrial fractions. Knockdown of OPA1 failed to reduce db-cAMP-induced phosphorylation of hormone-sensitive lipase (HSL), Ca(2+) signaling and aldosterone secretion. In conclusion, OPA1 could be detected in the post-mitochondrial fractions, nevertheless, OPA1 did not interfere with the cAMP - PKA - HSL mediated activation of aldosterone secretion.
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Affiliation(s)
- László Fülöp
- Department of Physiology, Faculty of Medicine, Semmelweis University, Hungary
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Hattangady N, Olala L, Bollag WB, Rainey WE. Acute and chronic regulation of aldosterone production. Mol Cell Endocrinol 2012; 350:151-62. [PMID: 21839803 PMCID: PMC3253327 DOI: 10.1016/j.mce.2011.07.034] [Citation(s) in RCA: 206] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 07/11/2011] [Accepted: 07/17/2011] [Indexed: 11/28/2022]
Abstract
Aldosterone is the major mineralocorticoid synthesized by the adrenal and plays an important role in the regulation of systemic blood pressure through the absorption of sodium and water. Aldosterone production is regulated tightly by selective expression of aldosterone synthase (CYP11B2) in the adrenal outermost zone, the zona glomerulosa. Angiotensin II (Ang II), potassium (K(+)) and adrenocorticotropin (ACTH) are the main physiological agonists which regulate aldosterone secretion. Aldosterone production is regulated within minutes of stimulation (acutely) through increased expression and phosphorylation of the steroidogenic acute regulatory (StAR) protein and over hours to days (chronically) by increased expression of the enzymes involved in the synthesis of aldosterone, particularly CYP11B2. Imbalance in any of these processes may lead to several disorders of aldosterone excess. In this review we attempt to summarize the key molecular events involved in the acute and chronic phases of aldosterone secretion.
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Affiliation(s)
- Namita Hattangady
- Department of Physiology, Georgia Health Sciences University (formerly the Medical College of Georgia), 1120 15 Street, Augusta, GA 30912
| | - Lawrence Olala
- Department of Physiology, Georgia Health Sciences University (formerly the Medical College of Georgia), 1120 15 Street, Augusta, GA 30912
| | - Wendy B. Bollag
- Department of Physiology, Georgia Health Sciences University (formerly the Medical College of Georgia), 1120 15 Street, Augusta, GA 30912
- Charlie Norwood VA Medical Center, One Freedom Way, Augusta, GA 30904
| | - William E. Rainey
- Department of Physiology, Georgia Health Sciences University (formerly the Medical College of Georgia), 1120 15 Street, Augusta, GA 30912
- To whom correspondence should be addressed: William E. Rainey, Department of Physiology, Georgia Health Sciences University, 1120 15 Street, Augusta, GA 30912, , Tel: (706) 721-7665, Fax: (706) 721-7299
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Spät A, Hunyady L. Control of aldosterone secretion: a model for convergence in cellular signaling pathways. Physiol Rev 2004; 84:489-539. [PMID: 15044681 DOI: 10.1152/physrev.00030.2003] [Citation(s) in RCA: 344] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Aldosterone secretion by glomerulosa cells is stimulated by angiotensin II (ANG II), extracellular K(+), corticotrophin, and several paracrine factors. Electrophysiological, fluorimetric, and molecular biological techniques have significantly clarified the molecular action of these stimuli. The steroidogenic effect of corticotrophin is mediated by adenylyl cyclase, whereas potassium activates voltage-operated Ca(2+) channels. ANG II, bound to AT(1) receptors, acts through the inositol 1,4,5-trisphosphate (IP(3))-Ca(2+)/calmodulin system. All three types of IP(3) receptors are coexpressed, rendering a complex control of Ca(2+) release possible. Ca(2+) release is followed by both capacitative and voltage-activated Ca(2+) influx. ANG II inhibits the background K(+) channel TASK and Na(+)-K(+)-ATPase, and the ensuing depolarization activates T-type (Ca(v)3.2) Ca(2+) channels. Activation of protein kinase C by diacylglycerol (DAG) inhibits aldosterone production, whereas the arachidonate released from DAG in ANG II-stimulated cells is converted by lipoxygenase to 12-hydroxyeicosatetraenoic acid, which may also induce Ca(2+) signaling. Feedback effects and cross-talk of signal-transducing pathways sensitize glomerulosa cells to low-intensity stimuli, such as physiological elevations of [K(+)] (< or =1 mM), ANG II, and ACTH. Ca(2+) signaling is also modified by cell swelling, as well as receptor desensitization, resensitization, and downregulation. Long-term regulation of glomerulosa cells involves cell growth and proliferation and induction of steroidogenic enzymes. Ca(2+), receptor, and nonreceptor tyrosine kinases and mitogen-activated kinases participate in these processes. Ca(2+)- and cAMP-dependent phosphorylation induce the transfer of the steroid precursor cholesterol from the cytoplasm to the inner mitochondrial membrane. Ca(2+) signaling, transferred into the mitochondria, stimulates the reduction of pyridine nucleotides.
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Affiliation(s)
- András Spät
- Dept. of Physiology, Semmelweis University, Faculty of Medicine, PO Box 259, H-1444 Budapest, Hungary.
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Abstract
The adrenal glomerulosa cells is the cell type most sensitive to extracellular K+ in the mammalian organism. Its sensitivity to physiological increases in K+ concentration ([K+]) is due to the expression of the two-pore domain K+ channels TASK that gives rise to K+ conductance in the range of resting membrane potential (approximately equal to -80mV) and to mechanisms that reduce the activation threshold of T-type voltage-activated Ca2+ channels. Potassium-induced cytoplasmic Ca2+ signal activates adenylyl cyclase; induces and activates StAR, the protein that carries cholesterol to the inner mitochondrial membrane and also enhances the expression of aldosterone synthase. The cytoplasmic Ca2+ signal is transferred into the mitochondrial matrix and enhances the reduction of mitochondrial pyridine nucleotides.
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Affiliation(s)
- András Spät
- Department of Physiology, Laboratory of Cellular and Molecular Physiology, Faculty of Medicine, Semmelweis University and Hungarian Academy of Sciences, P.O. Box 259, H-1444 Budapest, Hungary.
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Spät A, Pitter JG. The effect of cytoplasmic Ca2+ signal on the redox state of mitochondrial pyridine nucleotides. Mol Cell Endocrinol 2004; 215:115-8. [PMID: 15026183 DOI: 10.1016/j.mce.2003.11.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
As first observed in rat adrenal glomerulosa cells, cytoplasmic Ca(2+) signal, induced by K(+), angiotensin II or vasopressin, evokes an increase in the level of reduced mitochondrial pyridine nucleotides, NADH and NADPH. Prostaglandin F(2)alpha and extracellular ATP exert similar effects in rat ovarian luteal cells. This coupling of cytoplasmic Ca(2+) concentration and mitochondrial metabolism occurs also when the stimuli are applied at physiological concentration and under conditions when no formation of high-Ca(2+) perimitochondrial microdomains may be presumed. We present evidence that low submicromolar Ca(2+) signals in the cytoplasm can increase mitochondrial Ca(2+) concentration and activate mitochondrial dehydrogenation processes. Several observations support the assumption that intramitochondrial Ca(2+) signals play a significant role in the stimulation of steroid hormone production.
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Affiliation(s)
- András Spät
- Laboratory of Cellular and Molecular Physiology and Department of Physiology, Semmelweis University, Faculty of Medicine, P.O. Box 259, H-1444 Budapest, Hungary.
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