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Vinson GP. Functional Zonation of the Adult Mammalian Adrenal Cortex. Front Neurosci 2016; 10:238. [PMID: 27378832 PMCID: PMC4908136 DOI: 10.3389/fnins.2016.00238] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 05/17/2016] [Indexed: 12/31/2022] Open
Abstract
The standard model of adrenocortical zonation holds that the three main zones, glomerulosa, fasciculata, and reticularis each have a distinct function, producing mineralocorticoids (in fact just aldosterone), glucocorticoids, and androgens respectively. Moreover, each zone has its specific mechanism of regulation, though ACTH has actions throughout. Finally, the cells of the cortex originate from a stem cell population in the outer cortex or capsule, and migrate centripetally, changing their phenotype as they progress through the zones. Recent progress in understanding the development of the gland and the distribution of steroidogenic enzymes, trophic hormone receptors, and other factors suggests that this model needs refinement. Firstly, proliferation can take place throughout the gland, and although the stem cells are certainly located in the periphery, zonal replenishment can take place within zones. Perhaps more importantly, neither the distribution of enzymes nor receptors suggest that the individual zones are necessarily autonomous in their production of steroid. This is particularly true of the glomerulosa, which does not seem to have the full suite of enzymes required for aldosterone biosynthesis. Nor, in the rat anyway, does it express MC2R to account for the response of aldosterone to ACTH. It is known that in development, recruitment of stem cells is stimulated by signals from within the glomerulosa. Furthermore, throughout the cortex local regulatory factors, including cytokines, catecholamines and the tissue renin-angiotensin system, modify and refine the effects of the systemic trophic factors. In these and other ways it more and more appears that the functions of the gland should be viewed as an integrated whole, greater than the sum of its component parts.
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Affiliation(s)
- Gavin P Vinson
- School of Biological and Chemical Sciences, Queen Mary University of London London, UK
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52
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Manichaikul A, Rich SS, Allison MA, Guagliardo NA, Bayliss DA, Carey RM, Barrett PQ. KCNK3 Variants Are Associated With Hyperaldosteronism and Hypertension. Hypertension 2016; 68:356-64. [PMID: 27296998 DOI: 10.1161/hypertensionaha.116.07564] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 05/11/2016] [Indexed: 12/19/2022]
Abstract
Blood pressure (BP) is a complex trait that is the consequence of an interaction between genetic and environmental determinants. Previous studies have demonstrated increased BP in mice with global deletion of TASK-1 channels contemporaneous with diverse dysregulation of aldosterone production. In humans, genome-wide association studies in ≈100 000 individuals of European, East Asian, and South Asian ancestry identified a single nucleotide polymorphism (SNP) in KCNK3 (the gene encoding TASK-1) associated with mean arterial pressure. The current study was motivated by the hypotheses that (1) association of KCNK3 SNPs with BP and related traits extends to blacks and Hispanics, and (2) KCNK3 SNPs exhibit associations with plasma renin activity and aldosterone levels. We examined baseline BP measurements for 7840 participants from the Multi-Ethnic Study of Atherosclerosis (MESA), and aldosterone levels and plasma renin activity in a subset of 1653 MESA participants. We identified statistically significant association of the previously reported KCNK3 SNP (rs1275988) with mean arterial pressure in MESA blacks (P=0.024) and a nearby SNP (rs13394970) in MESA Hispanics (P=0.031). We discovered additional KCNK3 SNP associations with systolic BP, mean arterial pressure, and hypertension. We also identified statistically significant association of KCNK3 rs2586886 with plasma aldosterone level in MESA and demonstrated that global deletion of TASK-1 channels in mice produces a mild-hyperaldosteronism, not associated with a decrease in renin. Our results suggest that genetic variation in the KCNK3 gene may contribute to BP variation and less severe hypertensive disorders in which aldosterone may be one of several causative factors.
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Affiliation(s)
- Ani Manichaikul
- From the Center for Public Health Genomics (A.M., S.S.R.), Biostatistics Section, Department of Public Health Sciences (A.M.), Department of Pharmacology (N.A.G., D.A.B., P.Q.B.), and Division of Endocrinology and Metabolism and Department of Medicine (R.M.C.), University of Virginia, Charlottesville; and Department of Family and Preventive Medicine, University of California San Diego, La Jolla (M.A.A.)
| | - Stephen S Rich
- From the Center for Public Health Genomics (A.M., S.S.R.), Biostatistics Section, Department of Public Health Sciences (A.M.), Department of Pharmacology (N.A.G., D.A.B., P.Q.B.), and Division of Endocrinology and Metabolism and Department of Medicine (R.M.C.), University of Virginia, Charlottesville; and Department of Family and Preventive Medicine, University of California San Diego, La Jolla (M.A.A.)
| | - Matthew A Allison
- From the Center for Public Health Genomics (A.M., S.S.R.), Biostatistics Section, Department of Public Health Sciences (A.M.), Department of Pharmacology (N.A.G., D.A.B., P.Q.B.), and Division of Endocrinology and Metabolism and Department of Medicine (R.M.C.), University of Virginia, Charlottesville; and Department of Family and Preventive Medicine, University of California San Diego, La Jolla (M.A.A.)
| | - Nick A Guagliardo
- From the Center for Public Health Genomics (A.M., S.S.R.), Biostatistics Section, Department of Public Health Sciences (A.M.), Department of Pharmacology (N.A.G., D.A.B., P.Q.B.), and Division of Endocrinology and Metabolism and Department of Medicine (R.M.C.), University of Virginia, Charlottesville; and Department of Family and Preventive Medicine, University of California San Diego, La Jolla (M.A.A.)
| | - Douglas A Bayliss
- From the Center for Public Health Genomics (A.M., S.S.R.), Biostatistics Section, Department of Public Health Sciences (A.M.), Department of Pharmacology (N.A.G., D.A.B., P.Q.B.), and Division of Endocrinology and Metabolism and Department of Medicine (R.M.C.), University of Virginia, Charlottesville; and Department of Family and Preventive Medicine, University of California San Diego, La Jolla (M.A.A.)
| | - Robert M Carey
- From the Center for Public Health Genomics (A.M., S.S.R.), Biostatistics Section, Department of Public Health Sciences (A.M.), Department of Pharmacology (N.A.G., D.A.B., P.Q.B.), and Division of Endocrinology and Metabolism and Department of Medicine (R.M.C.), University of Virginia, Charlottesville; and Department of Family and Preventive Medicine, University of California San Diego, La Jolla (M.A.A.)
| | - Paula Q Barrett
- From the Center for Public Health Genomics (A.M., S.S.R.), Biostatistics Section, Department of Public Health Sciences (A.M.), Department of Pharmacology (N.A.G., D.A.B., P.Q.B.), and Division of Endocrinology and Metabolism and Department of Medicine (R.M.C.), University of Virginia, Charlottesville; and Department of Family and Preventive Medicine, University of California San Diego, La Jolla (M.A.A.).
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53
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Tauber P, Aichinger B, Christ C, Stindl J, Rhayem Y, Beuschlein F, Warth R, Bandulik S. Cellular Pathophysiology of an Adrenal Adenoma-Associated Mutant of the Plasma Membrane Ca(2+)-ATPase ATP2B3. Endocrinology 2016; 157:2489-99. [PMID: 27035656 DOI: 10.1210/en.2015-2029] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Adrenal aldosterone-producing adenomas (APAs) are a main cause for primary aldosteronism leading to arterial hypertension. Physiologically, aldosterone production in the adrenal gland is stimulated by angiotensin II and high extracellular potassium. These stimuli lead to a depolarization of the plasma membrane and, as a consequence, an increase of intracellular Ca(2+). Mutations of the plasma membrane Ca(2+)-ATPase ATP2B3 have been found in APAs with a prevalence of 0.6%-3.1%. Here, we investigated the effects of the APA-associated ATP2B3(Leu425_Val426del) mutation in adrenocortical NCI-H295R and human embryonic kidney (HEK-293) cells. Ca(2+) measurements revealed a higher basal Ca(2+) level in cells expressing the mutant ATP2B3. This rise in intracellular Ca(2+) was even more pronounced under conditions with high extracellular Ca(2+) pointing to an increased Ca(2+) influx associated with the mutated protein. Furthermore, cells with the mutant ATP2B3 appeared to have a reduced capacity to export Ca(2+) suggesting a loss of the physiological pump function. Surprisingly, expression of the mutant ATP2B3 caused a Na(+)-dependent inward current that strongly depolarized the plasma membrane and compromised the cytosolic cation composition. In parallel to these findings, mRNA expression of the cytochrome P450, family 11, subfamily B, polypeptide 2 (aldosterone synthase) was substantially increased and aldosterone production was enhanced in cells overexpressing mutant ATP2B3. In summary, the APA-associated ATP2B3(Leu425_Val426del) mutant promotes aldosterone production by at least 2 different mechanisms: 1) a reduced Ca(2+) export due to the loss of the physiological pump function; and 2) an increased Ca(2+) influx due to opening of depolarization-activated Ca(2+) channels as well as a possible Ca(2+) leak through the mutated pump.
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Affiliation(s)
- Philipp Tauber
- Medical Cell Biology (P.T., B.A., C.C., J.S., R.W., S.B.), University of Regensburg, 93053 Regensburg, Germany; and Medizinische Klinik und Poliklinik IV (Y.R., F.B.), Ludwig-Maximilians-Universität, 80336 Munich, Germany
| | - B Aichinger
- Medical Cell Biology (P.T., B.A., C.C., J.S., R.W., S.B.), University of Regensburg, 93053 Regensburg, Germany; and Medizinische Klinik und Poliklinik IV (Y.R., F.B.), Ludwig-Maximilians-Universität, 80336 Munich, Germany
| | - C Christ
- Medical Cell Biology (P.T., B.A., C.C., J.S., R.W., S.B.), University of Regensburg, 93053 Regensburg, Germany; and Medizinische Klinik und Poliklinik IV (Y.R., F.B.), Ludwig-Maximilians-Universität, 80336 Munich, Germany
| | - J Stindl
- Medical Cell Biology (P.T., B.A., C.C., J.S., R.W., S.B.), University of Regensburg, 93053 Regensburg, Germany; and Medizinische Klinik und Poliklinik IV (Y.R., F.B.), Ludwig-Maximilians-Universität, 80336 Munich, Germany
| | - Y Rhayem
- Medical Cell Biology (P.T., B.A., C.C., J.S., R.W., S.B.), University of Regensburg, 93053 Regensburg, Germany; and Medizinische Klinik und Poliklinik IV (Y.R., F.B.), Ludwig-Maximilians-Universität, 80336 Munich, Germany
| | - F Beuschlein
- Medical Cell Biology (P.T., B.A., C.C., J.S., R.W., S.B.), University of Regensburg, 93053 Regensburg, Germany; and Medizinische Klinik und Poliklinik IV (Y.R., F.B.), Ludwig-Maximilians-Universität, 80336 Munich, Germany
| | - R Warth
- Medical Cell Biology (P.T., B.A., C.C., J.S., R.W., S.B.), University of Regensburg, 93053 Regensburg, Germany; and Medizinische Klinik und Poliklinik IV (Y.R., F.B.), Ludwig-Maximilians-Universität, 80336 Munich, Germany
| | - S Bandulik
- Medical Cell Biology (P.T., B.A., C.C., J.S., R.W., S.B.), University of Regensburg, 93053 Regensburg, Germany; and Medizinische Klinik und Poliklinik IV (Y.R., F.B.), Ludwig-Maximilians-Universität, 80336 Munich, Germany
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54
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Gallo-Payet N. 60 YEARS OF POMC: Adrenal and extra-adrenal functions of ACTH. J Mol Endocrinol 2016; 56:T135-56. [PMID: 26793988 DOI: 10.1530/jme-15-0257] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 01/21/2016] [Indexed: 01/27/2023]
Abstract
The pituitary adrenocorticotropic hormone (ACTH) plays a pivotal role in homeostasis and stress response and is thus the major component of the hypothalamo-pituitary-adrenal axis. After a brief summary of ACTH production from proopiomelanocortin (POMC) and on ACTH receptor properties, the first part of the review covers the role of ACTH in steroidogenesis and steroid secretion. We highlight the mechanisms explaining the differential acute vs chronic effects of ACTH on aldosterone and glucocorticoid secretion. The second part summarizes the effects of ACTH on adrenal growth, addressing its role as either a mitogenic or a differentiating factor. We then review the mechanisms involved in steroid secretion, from the classical Cyclic adenosine monophosphate second messenger system to various signaling cascades. We also consider how the interaction between the extracellular matrix and the cytoskeleton may trigger activation of signaling platforms potentially stimulating or repressing the steroidogenic potency of ACTH. Finally, we consider the extra-adrenal actions of ACTH, in particular its role in differentiation in a variety of cell types, in addition to its known lipolytic effects on adipocytes. In each section, we endeavor to correlate basic mechanisms of ACTH function with the pathological consequences of ACTH signaling deficiency and of overproduction of ACTH.
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Affiliation(s)
- Nicole Gallo-Payet
- Division of EndocrinologyDepartment of Medicine, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada Division of EndocrinologyDepartment of Medicine, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Quebec, Canada
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55
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Larsen CK, Jensen IS, Sorensen MV, de Bruijn PI, Bleich M, Praetorius HA, Leipziger J. Hyperaldosteronism after decreased renal K+ excretion in KCNMB2 knockout mice. Am J Physiol Renal Physiol 2016; 310:F1035-46. [PMID: 26962098 DOI: 10.1152/ajprenal.00010.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 03/08/2016] [Indexed: 11/22/2022] Open
Abstract
The kidney is the primary organ ensuring K(+) homeostasis. K(+) is secreted into the urine in the distal tubule by two mechanisms: by the renal outer medullary K(+) channel (Kir1.1) and by the Ca(2+)-activated K(+) channel (KCa1.1). Here, we report a novel knockout mouse of the β2-subunit of the KCa1.1 channel (KCNMB2), which displays hyperaldosteronism after decreased renal K(+) excretion. KCNMB2(-/-) mice displayed hyperaldosteronism, normal plasma K(+) concentration, and produced dilute urine with decreased K(+) concentration. The normokalemia indicated that hyperaldosteronism did not result from primary aldosteronism. Activation of the renin-angiotensin-aldosterone system was also ruled out as renal renin mRNA expression was reduced in KCNMB2(-/-) mice. Renal K(+) excretion rates were similar in the two genotypes; however, KCNMB2(-/-) mice required elevated plasma aldosterone to achieve K(+) balance. Blockade of the mineralocorticoid receptor with eplerenone triggered mild hyperkalemia and unmasked reduced renal K(+) excretion in KCNMB2(-/-) mice. Knockout mice for the α-subunit of the KCa1.1 channel (KCNMA1(-/-) mice) have hyperaldosteronism, are hypertensive, and lack flow-induced K(+) secretion. KCNMB2(-/-) mice share the phenotypic traits of normokalemia and hyperaldosteronism with KCNMA1(-/-) mice but were normotensive and displayed intact flow-induced K(+) secretion. Despite elevated plasma aldosterone, KNCMB2(-/-) mice did not display salt-sensitive hypertension and were able to decrease plasma aldosterone on a high-Na(+) diet, although plasma aldosterone remained elevated in KCNMB2(-/-) mice. In summary, KCNMB2(-/-) mice have a reduced ability to excrete K(+) into the urine but achieve K(+) balance through an aldosterone-mediated, β2-independent mechanism. The phenotype of KCNMB2 mice was similar but milder than the phenotype of KCNMA1(-/-) mice.
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Affiliation(s)
- Casper K Larsen
- Department of Biomedicine, Physiology, and Health, Aarhus University, Aarhus, Denmark
| | - Iben S Jensen
- Department of Biomedicine, Physiology, and Health, Aarhus University, Aarhus, Denmark
| | - Mads V Sorensen
- Department of Biomedicine, Physiology, and Health, Aarhus University, Aarhus, Denmark; Aarhus Institute for Advanced Studies, Aarhus University, Aarhus, Denmark; and
| | - Pauline I de Bruijn
- Department of Biomedicine, Physiology, and Health, Aarhus University, Aarhus, Denmark
| | - Markus Bleich
- Institute of Physiology, Christian-Albrechts-University, Kiel, Germany
| | - Helle A Praetorius
- Department of Biomedicine, Physiology, and Health, Aarhus University, Aarhus, Denmark
| | - Jens Leipziger
- Department of Biomedicine, Physiology, and Health, Aarhus University, Aarhus, Denmark;
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56
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Lalli E, Barhanin J, Zennaro MC, Warth R. Local Control of Aldosterone Production and Primary Aldosteronism. Trends Endocrinol Metab 2016; 27:123-131. [PMID: 26803728 DOI: 10.1016/j.tem.2016.01.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 01/08/2016] [Accepted: 01/08/2016] [Indexed: 12/13/2022]
Abstract
Primary aldosteronism (PA) is caused by excessive production of aldosterone by the adrenal cortex and is determined by a benign aldosterone-producing adenoma (APA) in a significant proportion of cases. Local mechanisms, as opposed to circulatory ones, that control aldosterone production in the adrenal cortex are particularly relevant in the physiopathological setting and in the pathogenesis of PA. A breakthrough in our understanding of the pathogenetic mechanisms in APA has been the identification of somatic mutations in genes controlling membrane potential and intracellular calcium concentrations. However, recent data show that the processes of nodule formation and aldosterone hypersecretion can be dissociated in pathological adrenals and suggest a model envisaging different molecular events for the pathogenesis of APA.
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Affiliation(s)
- Enzo Lalli
- Institut de Pharmacologie Moléculaire et Cellulaire CNRS, 06560 Valbonne, France; NEOGENEX CNRS International Associated Laboratory, 06560 Valbonne, France; Université de Nice - Sophia Antipolis, 06560 Sophia Antipolis, France.
| | - Jacques Barhanin
- Laboratoire de PhysioMédecine Moléculaire CNRS-UNS UMR 7370, 06108 Nice Cedex 2, France; Laboratories of Excellence, Ion Channel Science and Therapeutics, 06107 Nice, France
| | - Maria-Christina Zennaro
- INSERM, UMRS 970, Paris Cardiovascular Research Center, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France; Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service de Génétique, 75015 Paris, France
| | - Richard Warth
- Medical Cell Biology - University of Regensburg, 93053 Regensburg, Germany
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57
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Basham KJ, Hung HA, Lerario AM, Hammer GD. Mouse models of adrenocortical tumors. Mol Cell Endocrinol 2016; 421:82-97. [PMID: 26678830 PMCID: PMC4720156 DOI: 10.1016/j.mce.2015.11.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Revised: 11/23/2015] [Accepted: 11/24/2015] [Indexed: 12/17/2022]
Abstract
The molecular basis of the organogenesis, homeostasis, and tumorigenesis of the adrenal cortex has been the subject of intense study for many decades. Specifically, characterization of tumor predisposition syndromes with adrenocortical manifestations and molecular profiling of sporadic adrenocortical tumors have led to the discovery of key molecular pathways that promote pathological adrenal growth. However, given the observational nature of such studies, several important questions regarding the molecular pathogenesis of adrenocortical tumors have remained. This review will summarize naturally occurring and genetically engineered mouse models that have provided novel tools to explore the molecular and cellular underpinnings of adrenocortical tumors. New paradigms of cancer initiation, maintenance, and progression that have emerged from this work will be discussed.
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Affiliation(s)
- Kaitlin J Basham
- Department of Internal Medicine, Division of Metabolism, Endocrinology, and Diabetes, USA; Endocrine Oncology Program, Comprehensive Cancer Center, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Holly A Hung
- Department of Internal Medicine, Division of Metabolism, Endocrinology, and Diabetes, USA; Endocrine Oncology Program, Comprehensive Cancer Center, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Antonio M Lerario
- Department of Internal Medicine, Division of Metabolism, Endocrinology, and Diabetes, USA; Endocrine Oncology Program, Comprehensive Cancer Center, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Gary D Hammer
- Department of Internal Medicine, Division of Metabolism, Endocrinology, and Diabetes, USA; Endocrine Oncology Program, Comprehensive Cancer Center, University of Michigan, Ann Arbor, MI, 48109, USA.
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58
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Leccia F, Batisse-Lignier M, Sahut-Barnola I, Val P, Lefrançois-Martinez AM, Martinez A. Mouse Models Recapitulating Human Adrenocortical Tumors: What Is Lacking? Front Endocrinol (Lausanne) 2016; 7:93. [PMID: 27471492 PMCID: PMC4945639 DOI: 10.3389/fendo.2016.00093] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 07/04/2016] [Indexed: 12/31/2022] Open
Abstract
Adrenal cortex tumors are divided into benign forms, such as primary hyperplasias and adrenocortical adenomas (ACAs), and malignant forms or adrenocortical carcinomas (ACCs). Primary hyperplasias are rare causes of adrenocorticotropin hormone-independent hypercortisolism. ACAs are the most common type of adrenal gland tumors and they are rarely "functional," i.e., producing steroids. When functional, adenomas result in endocrine disorders, such as Cushing's syndrome (hypercortisolism) or Conn's syndrome (hyperaldosteronism). By contrast, ACCs are extremely rare but highly aggressive tumors that may also lead to hypersecreting syndromes. Genetic analyses of patients with sporadic or familial forms of adrenocortical tumors (ACTs) led to the identification of potentially causative genes, most of them being involved in protein kinase A (PKA), Wnt/β-catenin, and P53 signaling pathways. Development of mouse models is a crucial step to firmly establish the functional significance of candidate genes, to dissect mechanisms leading to tumors and endocrine disorders, and in fine to provide in vivo tools for therapeutic screens. In this article, we will provide an overview on the existing mouse models (xenografted and genetically engineered) of ACTs by focusing on the role of PKA and Wnt/β-catenin pathways in this context. We will discuss the advantages and limitations of models that have been developed heretofore and we will point out necessary improvements in the development of next generation mouse models of adrenal diseases.
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Affiliation(s)
- Felicia Leccia
- UMR6293, GReD, INSERM U1103, CNRS, Clermont Université, Clermont-Ferrand, France
| | - Marie Batisse-Lignier
- UMR6293, GReD, INSERM U1103, CNRS, Clermont Université, Clermont-Ferrand, France
- Endocrinology, Diabetology and Metabolic Diseases Department, Centre Hospitalier Universitaire, School of Medicine, Clermont-Ferrand, France
| | | | - Pierre Val
- UMR6293, GReD, INSERM U1103, CNRS, Clermont Université, Clermont-Ferrand, France
| | | | - Antoine Martinez
- UMR6293, GReD, INSERM U1103, CNRS, Clermont Université, Clermont-Ferrand, France
- *Correspondence: Antoine Martinez,
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59
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Chen AX, Nishimoto K, Nanba K, Rainey WE. Potassium channels related to primary aldosteronism: Expression similarities and differences between human and rat adrenals. Mol Cell Endocrinol 2015; 417:141-8. [PMID: 26375812 PMCID: PMC4646165 DOI: 10.1016/j.mce.2015.09.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Revised: 08/18/2015] [Accepted: 09/10/2015] [Indexed: 11/26/2022]
Abstract
Three potassium channels have been associated with primary aldosteronism (PA) in rodents and humans: KCNK3 (TASK-1), KCNK9 (TASK-3), and KCNJ5 (Kir3.4). Mice with deficiency in Kcnk3 and Kcnk9 have elevated aldosterone production and blood pressure. In humans, adrenal tumors with somatic mutations in KCNJ5 cause PA. However, there are very few reports on the expression patterns of these genes in humans versus rodents. Herein, we compared human and rat mRNA expression (by quantitative real-time polymerase chain reaction (qPCR) and protein levels (by immunohistochemistry) across three tissues (adrenal, brain, heart) and two laser-captured adrenal zones (zona glomerulosa, zona fasciculata). Our findings show that expression patterns of KCNK3, KCNK9, and KCNJ5 are inconsistent between rats and humans across both tissues and adrenal zones. Thus, species variation in the expression of PA-related potassium channels indicates an evolutionary divergence in their role in regulating adrenal aldosterone production.
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Affiliation(s)
- Andrew X Chen
- Department of Molecular and Integrative Physiology, University of Michigan, 1150 W. Medical Center Dr, Ann Arbor, MI 48109, USA; Department of Internal Medicine, University of Michigan, 1150 W. Medical Center Dr, Ann Arbor, MI 48109, USA
| | - Koshiro Nishimoto
- Department of Molecular and Integrative Physiology, University of Michigan, 1150 W. Medical Center Dr, Ann Arbor, MI 48109, USA; Department of Internal Medicine, University of Michigan, 1150 W. Medical Center Dr, Ann Arbor, MI 48109, USA
| | - Kazutaka Nanba
- Department of Molecular and Integrative Physiology, University of Michigan, 1150 W. Medical Center Dr, Ann Arbor, MI 48109, USA; Department of Internal Medicine, University of Michigan, 1150 W. Medical Center Dr, Ann Arbor, MI 48109, USA
| | - William E Rainey
- Department of Molecular and Integrative Physiology, University of Michigan, 1150 W. Medical Center Dr, Ann Arbor, MI 48109, USA; Department of Internal Medicine, University of Michigan, 1150 W. Medical Center Dr, Ann Arbor, MI 48109, USA.
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60
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Stindl J, Tauber P, Sterner C, Tegtmeier I, Warth R, Bandulik S. Pathogenesis of Adrenal Aldosterone-Producing Adenomas Carrying Mutations of the Na(+)/K(+)-ATPase. Endocrinology 2015; 156:4582-91. [PMID: 26418325 DOI: 10.1210/en.2015-1466] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Aldosterone-producing adenoma (APA) is a major cause of primary aldosteronism, leading to secondary hypertension. Somatic mutations in the gene for the α1 subunit of the Na(+)/K(+)-ATPase were found in about 6% of APAs. APA-related α1 subunit of the Na(+)/K(+)-ATPase mutations lead to a loss of the pump function of the Na(+)/K(+)-ATPase, which is believed to result in membrane depolarization and Ca(2+)-dependent stimulation of aldosterone synthesis in adrenal cells. In addition, H(+) and Na(+) leak currents via the mutant Na(+)/K(+)-ATPase were suggested to contribute to the phenotype. The aim of this study was to investigate the cellular pathophysiology of adenoma-associated Na(+)/K(+)-ATPase mutants (L104R, V332G, G99R) in adrenocortical NCI-H295R cells. The expression of these Na(+)/K(+)-ATPase mutants depolarized adrenal cells and stimulated aldosterone secretion. However, an increase of basal cytosolic Ca(2+) levels in Na(+)/K(+)-ATPase mutant cells was not detectable, and stimulation with high extracellular K(+) hardly increased Ca(2+) levels in cells expressing L104R and V332G mutant Na(+)/K(+)-ATPase. Cytosolic pH measurements revealed an acidification of L104R and V332G mutant cells, despite an increased activity of the Na(+)/H(+) exchanger. The possible contribution of cellular acidification to the hypersecretion of aldosterone was supported by the observation that aldosterone secretion of normal adrenocortical cells was stimulated by acetate-induced acidification. Taken together, mutations of the Na(+)/K(+)-ATPase depolarize adrenocortical cells, disturb the K(+) sensitivity, and lower intracellular pH but, surprisingly, do not induce an overt increase of intracellular Ca(2+). Probably, the autonomous aldosterone secretion is caused by the concerted action of several pathological signaling pathways and incomplete cellular compensation.
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Affiliation(s)
- J Stindl
- Medical Cell Biology, University of Regensburg, 93053 Regensburg, Germany
| | - P Tauber
- Medical Cell Biology, University of Regensburg, 93053 Regensburg, Germany
| | - C Sterner
- Medical Cell Biology, University of Regensburg, 93053 Regensburg, Germany
| | - I Tegtmeier
- Medical Cell Biology, University of Regensburg, 93053 Regensburg, Germany
| | - R Warth
- Medical Cell Biology, University of Regensburg, 93053 Regensburg, Germany
| | - S Bandulik
- Medical Cell Biology, University of Regensburg, 93053 Regensburg, Germany
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61
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Zennaro MC, Fernandes-Rosa F, Boulkroun S, Jeunemaitre X. Bilateral Idiopathic Adrenal Hyperplasia: Genetics and Beyond. Horm Metab Res 2015; 47:947-52. [PMID: 26610199 DOI: 10.1055/s-0035-1565198] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Bilateral adrenal hyperplasia currently accounts for up to 2 thirds of cases of primary aldosteronism. As such, it represents a major opportunity for targeted medical management as opposed to unilateral surgically correctable forms of the disease. Although the majority of cases of primary aldosteronism are sporadic, bilateral adrenal hyperplasia may occur in the context of familial hyperaldosteronism where it is associated with specific germline mutations. Over the past 5 years, impressive progress has been made in our understanding of the genetic basis underlying primary aldosteronism, allowing us to identify and characterize new familial forms of the disease and to understand the mechanisms involved in the formation of aldosterone producing adenoma. In contrast, our knowledge of the genetic contribution to the development of bilateral adrenal hyperplasia, and in a larger context, to renin and aldosterone levels in the general population, is still poor. This review summarizes our current knowledge on the genetics of bilateral adrenal hyperplasia and addresses some open questions to be addressed by future research. In particular, genome-wide association studies in large populations may provide clues to understanding the genetic susceptibility underlying the development of primary aldosteronism.
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Affiliation(s)
- M-C Zennaro
- INSERM, UMRS 970, Paris Cardiovascular Research Center, Paris, France
| | - F Fernandes-Rosa
- INSERM, UMRS 970, Paris Cardiovascular Research Center, Paris, France
| | - S Boulkroun
- INSERM, UMRS 970, Paris Cardiovascular Research Center, Paris, France
| | - X Jeunemaitre
- INSERM, UMRS 970, Paris Cardiovascular Research Center, Paris, France
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62
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Pisani DF, Beranger GE, Corinus A, Giroud M, Ghandour RA, Altirriba J, Chambard JC, Mazure NM, Bendahhou S, Duranton C, Michiels JF, Frontini A, Rohner-Jeanrenaud F, Cinti S, Christian M, Barhanin J, Amri EZ. The K+ channel TASK1 modulates β-adrenergic response in brown adipose tissue through the mineralocorticoid receptor pathway. FASEB J 2015; 30:909-22. [PMID: 26527067 DOI: 10.1096/fj.15-277475] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 10/19/2015] [Indexed: 01/26/2023]
Abstract
Brown adipose tissue (BAT) is essential for adaptive thermogenesis and dissipation of caloric excess through the activity of uncoupling protein (UCP)-1. BAT in humans is of great interest for the treatment of obesity and related diseases. In this study, the expression of Twik-related acid-sensitive K(+) channel (TASK)-1 [a pH-sensitive potassium channel encoded by the potassium channel, 2-pore domain, subfamily K, member 3 (Kcnk3) gene] correlated highly with Ucp1 expression in obese and cold-exposed mice. In addition, Task1-null mice, compared with their controls, became overweight, mainly because of an increase in white adipose tissue mass and BAT whitening. Task1(-/-)-mouse-derived brown adipocytes, compared with wild-type mouse-derived brown adipocytes, displayed an impaired β3-adrenergic receptor response that was characterized by a decrease in oxygen consumption, Ucp1 expression, and lipolysis. This phenotype was thought to be caused by an exacerbation of mineralocorticoid receptor (MR) signaling, given that it was mimicked by corticoids and reversed by an MR inhibitor. We concluded that the K(+) channel TASK1 controls the thermogenic activity in brown adipocytes through modulation of β-adrenergic receptor signaling.
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Affiliation(s)
- Didier F Pisani
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Guillaume E Beranger
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Alain Corinus
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Maude Giroud
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Rayane A Ghandour
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Jordi Altirriba
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Jean-Claude Chambard
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Nathalie M Mazure
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Saïd Bendahhou
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Christophe Duranton
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Jean-François Michiels
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Andrea Frontini
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Françoise Rohner-Jeanrenaud
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Saverio Cinti
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Mark Christian
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Jacques Barhanin
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
| | - Ez-Zoubir Amri
- *University of Nice Sophia Antipolis, Nice, France; Centre National de la Recherche Scientifique (CNRS), Institut de Biologie Valrose (iBV), Unité Mixte de Recherche (UMR) 7277, Nice, France; U1091, iBV, INSERM, Nice, France; UMR 7370 and Laboratories of Excellence, Ion Channel Science and Therapeutics, Laboratoire de PhysioMédecine Moléculaire (LP2M), CNRS, Nice, France; Laboratory of Metabolism, Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva, Switzerland, UMR 7284 and **U1081, CNRS, Institute for Research in Cancer and Aging in Nice, INSERM, Nice, France; Anatomopathology Service, Pasteur Hospital, Centre Hospitalier Universitaire de Nice, Nice, France; Obesity Center, Department of Experimental and Clinical Medicine, Ancona, Italy; Warwick Medical School, University of Warwick, Coventry, United Kingdom
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63
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Zhou X, Chen K, Wang Y, Schuman M, Lei H, Sun Z. Antiaging Gene Klotho Regulates Adrenal CYP11B2 Expression and Aldosterone Synthesis. J Am Soc Nephrol 2015; 27:1765-76. [PMID: 26471128 DOI: 10.1681/asn.2015010093] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 08/27/2015] [Indexed: 12/11/2022] Open
Abstract
Deficiency of the antiaging gene Klotho (KL) induces renal damage and hypertension through unknown mechanisms. In this study, we assessed whether KL regulates expression of CYP11B2, a key rate-limiting enzyme in aldosterone synthesis, in adrenal glands. We found that haplodeficiency of KL(+/-) in mice increased the plasma level of aldosterone by 16 weeks of age, which coincided with spontaneous and persistent elevation of BP. Blockade of aldosterone actions by eplerenone reversed KL deficiency-induced hypertension and attenuated the kidney damage. Protein expression of CYP11B2 was upregulated in adrenal cortex of KL(+/-) mice. KL and CYP11B2 proteins colocalized in adrenal zona glomerulosa cells. Silencing of KL upregulated and overexpression of KL downregulated CYP11B2 expression in human adrenocortical cells. Notably, silencing of KL decreased expression of SF-1, a negative transcription factor of CYP11B2, but increased phosphorylation of ATF2, a positive transcription factor of CYP11B2, which may contribute to upregulation of CYP11B2 expression. Therefore, these results show that KL regulates adrenal CYP11B2 expression. KL deficiency-induced spontaneous hypertension and kidney damage may be partially attributed to the upregulation of CYP11B2 expression and aldosterone synthesis.
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Affiliation(s)
- Xiaoli Zhou
- Department of Cardiology, First Affiliated Hospital, Chongqing Medical University, Chongqing, China; and Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Kai Chen
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Yongjun Wang
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Mariano Schuman
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Han Lei
- Department of Cardiology, First Affiliated Hospital, Chongqing Medical University, Chongqing, China; and
| | - Zhongjie Sun
- Department of Physiology, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
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Drelon C, Berthon A, Mathieu M, Martinez A, Val P. Adrenal cortex tissue homeostasis and zonation: A WNT perspective. Mol Cell Endocrinol 2015; 408:156-64. [PMID: 25542843 DOI: 10.1016/j.mce.2014.12.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 12/18/2014] [Accepted: 12/18/2014] [Indexed: 11/19/2022]
Abstract
The adrenal cortex plays essential roles in the control of sodium and water homeostasis, stress response, inflammation and metabolism, through secretion of glucocorticoids and mineralocorticoids. Coordinated production of these hormones relies on functional zonation of the cortex, characterised by expression of Cyp11b2 under the control of angiotensin II and plasma potassium level in zona glomerulosa (ZG) and Cyp11b1 under the control of ACTH in zona fasciculata (ZF). The mechanisms involved in the establishment of functional zonation and its maintenance during centripetal cortex cell renewal are still poorly understood. Here, we hypothesise that the hormonal and signalling pathways that control adrenal cortex function are also involved in cortical zonation. In particular, we summarise evidence on the role of WNT/β-catenin signalling in ZG differentiation and how tight control of its activity is required to shape the adult cortex. In this context, we discuss the potential role of known WNT regulators and the possibility of a reciprocal cross-talk between PKA and WNT signalling.
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Affiliation(s)
- Coralie Drelon
- Laboratoire Génétique Reproduction et Développement -GReD- CNRS UMR 6293, Inserm U1103, Clermont Université, 24 Avenue des Landais, Aubière Cedex 63171, France
| | - Annabel Berthon
- Laboratoire Génétique Reproduction et Développement -GReD- CNRS UMR 6293, Inserm U1103, Clermont Université, 24 Avenue des Landais, Aubière Cedex 63171, France; Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland 20892-1103, USA
| | - Mickael Mathieu
- Laboratoire Génétique Reproduction et Développement -GReD- CNRS UMR 6293, Inserm U1103, Clermont Université, 24 Avenue des Landais, Aubière Cedex 63171, France
| | - Antoine Martinez
- Laboratoire Génétique Reproduction et Développement -GReD- CNRS UMR 6293, Inserm U1103, Clermont Université, 24 Avenue des Landais, Aubière Cedex 63171, France
| | - Pierre Val
- Laboratoire Génétique Reproduction et Développement -GReD- CNRS UMR 6293, Inserm U1103, Clermont Université, 24 Avenue des Landais, Aubière Cedex 63171, France.
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Bandulik S, Tauber P, Lalli E, Barhanin J, Warth R. Two-pore domain potassium channels in the adrenal cortex. Pflugers Arch 2015; 467:1027-42. [PMID: 25339223 PMCID: PMC4428839 DOI: 10.1007/s00424-014-1628-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 10/02/2014] [Accepted: 10/03/2014] [Indexed: 12/31/2022]
Abstract
The physiological control of steroid hormone secretion from the adrenal cortex depends on the function of potassium channels. The "two-pore domain K(+) channels" (K2P) TWIK-related acid sensitive K(+) channel 1 (TASK1), TASK3, and TWIK-related K(+) channel 1 (TREK1) are strongly expressed in adrenocortical cells. They confer a background K(+) conductance to these cells which is important for the K(+) sensitivity as well as for angiotensin II and adrenocorticotropic hormone-dependent stimulation of aldosterone and cortisol synthesis. Mice with single deletions of the Task1 or Task3 gene as well as Task1/Task3 double knockout mice display partially autonomous aldosterone synthesis. It appears that TASK1 and TASK3 serve different functions: TASK1 affects cell differentiation and prevents expression of aldosterone synthase in the zona fasciculata, while TASK3 controls aldosterone secretion in glomerulosa cells. TREK1 is involved in the regulation of cortisol secretion in fasciculata cells. These data suggest that a disturbed function of K2P channels could contribute to adrenocortical pathologies in humans.
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Affiliation(s)
- Sascha Bandulik
- Medical Cell Biology, University of Regensburg, Universitaetsstrasse 31, 93053, Regensburg, Germany,
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66
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Renigunta V, Schlichthörl G, Daut J. Much more than a leak: structure and function of K₂p-channels. Pflugers Arch 2015; 467:867-94. [PMID: 25791628 DOI: 10.1007/s00424-015-1703-7] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 03/09/2015] [Indexed: 11/27/2022]
Abstract
Over the last decade, we have seen an enormous increase in the number of experimental studies on two-pore-domain potassium channels (K2P-channels). The collection of reviews and original articles compiled for this special issue of Pflügers Archiv aims to give an up-to-date summary of what is known about the physiology and pathophysiology of K2P-channels. This introductory overview briefly describes the structure of K2P-channels and their function in different organs. Its main aim is to provide some background information for the 19 reviews and original articles of this special issue of Pflügers Archiv. It is not intended to be a comprehensive review; instead, this introductory overview focuses on some unresolved questions and controversial issues, such as: Do K2P-channels display voltage-dependent gating? Do K2P-channels contribute to the generation of action potentials? What is the functional role of alternative translation initiation? Do K2P-channels have one or two or more gates? We come to the conclusion that we are just beginning to understand the extremely complex regulation of these fascinating channels, which are often inadequately described as 'leak channels'.
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Affiliation(s)
- Vijay Renigunta
- Institute of Physiology and Pathophysiology, Marburg University, 35037, Marburg, Germany
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67
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Sepúlveda FV, Pablo Cid L, Teulon J, Niemeyer MI. Molecular aspects of structure, gating, and physiology of pH-sensitive background K2P and Kir K+-transport channels. Physiol Rev 2015; 95:179-217. [PMID: 25540142 DOI: 10.1152/physrev.00016.2014] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
K(+) channels fulfill roles spanning from the control of excitability to the regulation of transepithelial transport. Here we review two groups of K(+) channels, pH-regulated K2P channels and the transport group of Kir channels. After considering advances in the molecular aspects of their gating based on structural and functional studies, we examine their participation in certain chosen physiological and pathophysiological scenarios. Crystal structures of K2P and Kir channels reveal rather unique features with important consequences for the gating mechanisms. Important tasks of these channels are discussed in kidney physiology and disease, K(+) homeostasis in the brain by Kir channel-equipped glia, and central functions in the hearing mechanism in the inner ear and in acid secretion by parietal cells in the stomach. K2P channels fulfill a crucial part in central chemoreception probably by virtue of their pH sensitivity and are central to adrenal secretion of aldosterone. Finally, some unorthodox behaviors of the selectivity filters of K2P channels might explain their normal and pathological functions. Although a great deal has been learned about structure, molecular details of gating, and physiological functions of K2P and Kir K(+)-transport channels, this has been only scratching at the surface. More molecular and animal studies are clearly needed to deepen our knowledge.
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Affiliation(s)
- Francisco V Sepúlveda
- Centro de Estudios Científicos, Valdivia, Chile; UPMC Université Paris 06, Team 3, Paris, France; and Institut National de la Santé et de la Recherche Médicale, UMR_S 1138, Paris, France
| | - L Pablo Cid
- Centro de Estudios Científicos, Valdivia, Chile; UPMC Université Paris 06, Team 3, Paris, France; and Institut National de la Santé et de la Recherche Médicale, UMR_S 1138, Paris, France
| | - Jacques Teulon
- Centro de Estudios Científicos, Valdivia, Chile; UPMC Université Paris 06, Team 3, Paris, France; and Institut National de la Santé et de la Recherche Médicale, UMR_S 1138, Paris, France
| | - María Isabel Niemeyer
- Centro de Estudios Científicos, Valdivia, Chile; UPMC Université Paris 06, Team 3, Paris, France; and Institut National de la Santé et de la Recherche Médicale, UMR_S 1138, Paris, France
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68
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Abstract
Aldosterone is a steroid hormone synthesized in and secreted from the outer layer of the adrenal cortex, the zona glomerulosa. Aldosterone is responsible for regulating sodium homeostasis, thereby helping to control blood volume and blood pressure. Insufficient aldosterone secretion can lead to hypotension and circulatory shock, particularly in infancy. On the other hand, excessive aldosterone levels, or those too high for sodium status, can cause hypertension and exacerbate the effects of high blood pressure on multiple organs, contributing to renal disease, stroke, visual loss, and congestive heart failure. Aldosterone is also thought to directly induce end-organ damage, including in the kidneys and heart. Because of the significance of aldosterone to the physiology and pathophysiology of the cardiovascular system, it is important to understand the regulation of its biosynthesis and secretion from the adrenal cortex. Herein, the mechanisms regulating aldosterone production in zona glomerulosa cells are discussed, with a particular emphasis on signaling pathways involved in the secretory response to the main controllers of aldosterone production, the renin-angiotensin II system, serum potassium levels and adrenocorticotrophic hormone. The signaling pathways involved include phospholipase C-mediated phosphoinositide hydrolysis, inositol 1,4,5-trisphosphate, cytosolic calcium levels, calcium influx pathways, calcium/calmodulin-dependent protein kinases, diacylglycerol, protein kinases C and D, 12-hydroxyeicostetraenoic acid, phospholipase D, mitogen-activated protein kinase pathways, tyrosine kinases, adenylate cyclase, and cAMP-dependent protein kinase. A complete understanding of the signaling events regulating aldosterone biosynthesis may allow the identification of novel targets for therapeutic interventions in hypertension, primary aldosteronism, congestive heart failure, renal disease, and other cardiovascular disorders.
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Affiliation(s)
- Wendy B Bollag
- Charlie Norwood VA Medical Center, Augusta, Georgia; Department of Physiology, Medical College of Georgia at Georgia Regents University, Augusta, Georgia
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69
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Magill SB. Pathophysiology, diagnosis, and treatment of mineralocorticoid disorders. Compr Physiol 2015; 4:1083-119. [PMID: 24944031 DOI: 10.1002/cphy.c130042] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The renin-angiotensin-aldosterone system (RAAS) is a major regulator of blood pressure control, fluid, and electrolyte balance in humans. Chronic activation of mineralocorticoid production leads to dysregulation of the cardiovascular system and to hypertension. The key mineralocorticoid is aldosterone. Hyperaldosteronism causes sodium and fluid retention in the kidney. Combined with the actions of angiotensin II, chronic elevation in aldosterone leads to detrimental effects in the vasculature, heart, and brain. The adverse effects of excess aldosterone are heavily dependent on increased dietary salt intake as has been demonstrated in animal models and in humans. Hypertension develops due to complex genetic influences combined with environmental factors. In the last two decades, primary aldosteronism has been found to occur in 5% to 13% of subjects with hypertension. In addition, patients with hyperaldosteronism have more end organ manifestations such as left ventricular hypertrophy and have significant cardiovascular complications including higher rates of heart failure and atrial fibrillation compared to similarly matched patients with essential hypertension. The pathophysiology, diagnosis, and treatment of primary aldosteronism will be extensively reviewed. There are many pitfalls in the diagnosis and confirmation of the disorder that will be discussed. Other rare forms of hyper- and hypo-aldosteronism and unusual disorders of hypertension will also be reviewed in this article.
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Affiliation(s)
- Steven B Magill
- Division of Endocrinology, Metabolism, and Clinical Nutrition, Department of Medicine, Medical College of Wisconsin, Menomonee Falls, Wisconsin
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70
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Abstract
The purpose of this article is to review fundamentals in adrenal gland histophysiology. Key findings regarding the important signaling pathways involved in the regulation of steroidogenesis and adrenal growth are summarized. We illustrate how adrenal gland morphology and function are deeply interconnected in which novel signaling pathways (Wnt, Sonic hedgehog, Notch, β-catenin) or ionic channels are required for their integrity. Emphasis is given to exploring the mechanisms and challenges underlying the regulation of proliferation, growth, and functionality. Also addressed is the fact that while it is now well-accepted that steroidogenesis results from an enzymatic shuttle between mitochondria and endoplasmic reticulum, key questions still remain on the various aspects related to cellular uptake and delivery of free cholesterol. The significant progress achieved over the past decade regarding the precise molecular mechanisms by which the two main regulators of adrenal cortex, adrenocorticotropin hormone (ACTH) and angiotensin II act on their receptors is reviewed, including structure-activity relationships and their potential applications. Particular attention has been given to crucial second messengers and how various kinases, phosphatases, and cytoskeleton-associated proteins interact to ensure homeostasis and/or meet physiological demands. References to animal studies are also made in an attempt to unravel associated clinical conditions. Many of the aspects addressed in this article still represent a challenge for future studies, their outcome aimed at providing evidence that the adrenal gland, through its steroid hormones, occupies a central position in many situations where homeostasis is disrupted, thus highlighting the relevance of exploring and understanding how this key organ is regulated. © 2014 American Physiological Society. Compr Physiol 4:889-964, 2014.
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Affiliation(s)
- Nicole Gallo-Payet
- Division of Endocrinology, Department of Medicine, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, and Centre de Recherche Clinique Étienne-Le Bel of the Centre Hospitalier Universitaire de Sherbrooke (CHUS), Sherbrooke, Quebec, Canada
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71
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Abstract
Primary aldosteronism (PA) is the most common and curable form of secondary hypertension. It is caused in the majority of cases by either unilateral aldosterone overproduction due to an aldosterone-producing adenoma (APA) or by bilateral adrenal hyperplasia. Recent advances in genome technology have allowed researchers to unravel part of the genetic abnormalities underlying the development of APA and familial hyperaldosteronism. Recurrent somatic mutations in genes coding for ion channels (KCNJ5 and CACNA1D) and ATPases (ATP1A1 and ATP2B3) regulating intracellular ionic homeostasis and cell membrane potential have been identified in APA. Similar germline mutations of KCNJ5 were identified in a severe familial form of PA, familial hyperaldosteronism type 3 (FH3), whereas de novo germline CACNA1D mutations were found in two cases of hyperaldosteronism associated with a complex neurological disorder. These results have allowed a pathophysiological model of APA development to be established. This model involves modifications in intracellular ionic homeostasis and membrane potential, accounting for ∼50% of all tumors, associated with specific gender differences and severity of PA. In this review, we describe the different genetic abnormalities associated with PA and discuss the mechanisms whereby they lead to increased aldosterone production and cell proliferation. We also address some of the foreseeable consequences that genetic knowledge may contribute to improve diagnosis and patient care.
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Affiliation(s)
- Maria-Christina Zennaro
- INSERMUMRS_970, Paris Cardiovascular Research Center - PARCC, 56, rue Leblanc, 75015 Paris, FranceUniversity Paris DescartesSorbonne Paris Cité, Paris, FranceAssistance Publique-Hôpitaux de ParisHôpital Européen Georges Pompidou, Service de Génétique, Paris, France INSERMUMRS_970, Paris Cardiovascular Research Center - PARCC, 56, rue Leblanc, 75015 Paris, FranceUniversity Paris DescartesSorbonne Paris Cité, Paris, FranceAssistance Publique-Hôpitaux de ParisHôpital Européen Georges Pompidou, Service de Génétique, Paris, France INSERMUMRS_970, Paris Cardiovascular Research Center - PARCC, 56, rue Leblanc, 75015 Paris, FranceUniversity Paris DescartesSorbonne Paris Cité, Paris, FranceAssistance Publique-Hôpitaux de ParisHôpital Européen Georges Pompidou, Service de Génétique, Paris, France
| | - Sheerazed Boulkroun
- INSERMUMRS_970, Paris Cardiovascular Research Center - PARCC, 56, rue Leblanc, 75015 Paris, FranceUniversity Paris DescartesSorbonne Paris Cité, Paris, FranceAssistance Publique-Hôpitaux de ParisHôpital Européen Georges Pompidou, Service de Génétique, Paris, France INSERMUMRS_970, Paris Cardiovascular Research Center - PARCC, 56, rue Leblanc, 75015 Paris, FranceUniversity Paris DescartesSorbonne Paris Cité, Paris, FranceAssistance Publique-Hôpitaux de ParisHôpital Européen Georges Pompidou, Service de Génétique, Paris, France
| | - Fabio Fernandes-Rosa
- INSERMUMRS_970, Paris Cardiovascular Research Center - PARCC, 56, rue Leblanc, 75015 Paris, FranceUniversity Paris DescartesSorbonne Paris Cité, Paris, FranceAssistance Publique-Hôpitaux de ParisHôpital Européen Georges Pompidou, Service de Génétique, Paris, France INSERMUMRS_970, Paris Cardiovascular Research Center - PARCC, 56, rue Leblanc, 75015 Paris, FranceUniversity Paris DescartesSorbonne Paris Cité, Paris, FranceAssistance Publique-Hôpitaux de ParisHôpital Européen Georges Pompidou, Service de Génétique, Paris, France INSERMUMRS_970, Paris Cardiovascular Research Center - PARCC, 56, rue Leblanc, 75015 Paris, FranceUniversity Paris DescartesSorbonne Paris Cité, Paris, FranceAssistance Publique-Hôpitaux de ParisHôpital Européen Georges Pompidou, Service de Génétique, Paris, France
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72
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Feliciangeli S, Chatelain FC, Bichet D, Lesage F. The family of K2P channels: salient structural and functional properties. J Physiol 2015; 593:2587-603. [PMID: 25530075 DOI: 10.1113/jphysiol.2014.287268] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Accepted: 12/10/2014] [Indexed: 12/11/2022] Open
Abstract
Potassium channels participate in many biological functions, from ion homeostasis to generation and modulation of the electrical membrane potential. They are involved in a large variety of diseases. In the human genome, 15 genes code for K(+) channels with two pore domains (K2P ). These channels form dimers of pore-forming subunits that produce background conductances finely regulated by a range of natural and chemical effectors, including signalling lipids, temperature, pressure, pH, antidepressants and volatile anaesthetics. Since the cloning of TWIK1, the prototypical member of this family, a lot of work has been carried out on their structure and biology. These studies are still in progress, but data gathered so far show that K2P channels are central players in many processes, including ion homeostasis, hormone secretion, cell development and excitability. A growing number of studies underline their implication in physiopathological mechanisms, such as vascular and pulmonary hypertension, cardiac arrhythmias, nociception, neuroprotection and depression. This review gives a synthetic view of the most noticeable features of these channels.
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Affiliation(s)
- Sylvain Feliciangeli
- LabEx ICST, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS and Université de Nice-Sophia Antipolis, 660 Route des Lucioles, 06560, Valbonne, France
| | - Frank C Chatelain
- LabEx ICST, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS and Université de Nice-Sophia Antipolis, 660 Route des Lucioles, 06560, Valbonne, France
| | - Delphine Bichet
- LabEx ICST, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS and Université de Nice-Sophia Antipolis, 660 Route des Lucioles, 06560, Valbonne, France
| | - Florian Lesage
- LabEx ICST, Institut de Pharmacologie Moléculaire et Cellulaire, CNRS and Université de Nice-Sophia Antipolis, 660 Route des Lucioles, 06560, Valbonne, France
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73
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Monticone S, Else T, Mulatero P, Williams TA, Rainey WE. Understanding primary aldosteronism: impact of next generation sequencing and expression profiling. Mol Cell Endocrinol 2015; 399:311-20. [PMID: 25240470 PMCID: PMC4285708 DOI: 10.1016/j.mce.2014.09.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Revised: 09/11/2014] [Accepted: 09/15/2014] [Indexed: 10/24/2022]
Abstract
Primary aldosteronism (PA) encompasses a broad, heterogeneous group of disorders including both sporadic and familial forms (familial hyperaldosteronism type I, II and III). PA is the most common form of secondary hypertension and associated with a higher rate of cardiovascular complications, compared with essential hypertension. Despite significant progress in the diagnosis and management of PA, until recently the molecular mechanisms leading to inappropriate aldosterone production were largely unknown. The introduction of next-generation sequencing has had a profound impact on the field of human genetics and has given new insight in the molecular determinants that lead to both sporadic and familial forms of PA. Here we review the recent progress toward understanding of the genetic and molecular mechanisms leading to autonomous aldosterone production in PA.
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Affiliation(s)
- Silvia Monticone
- Department of Medical Sciences, Division of Internal Medicine and Hypertension, University of Torino, Torino, Italy.
| | - Tobias Else
- Department of Internal Medicine, Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Paolo Mulatero
- Department of Medical Sciences, Division of Internal Medicine and Hypertension, University of Torino, Torino, Italy
| | - Tracy A Williams
- Department of Medical Sciences, Division of Internal Medicine and Hypertension, University of Torino, Torino, Italy
| | - William E Rainey
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
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74
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Boulkroun S, Fernandes-Rosa FL, Zennaro MC. Molecular and Cellular Mechanisms of Aldosterone Producing Adenoma Development. Front Endocrinol (Lausanne) 2015; 6:95. [PMID: 26124749 PMCID: PMC4464054 DOI: 10.3389/fendo.2015.00095] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 05/26/2015] [Indexed: 01/19/2023] Open
Abstract
Primary aldosteronism (PA) is the most common form of secondary hypertension with an estimated prevalence of ~10% in referred patients. PA occurs as a result of a dysregulation of the normal mechanisms controlling adrenal aldosterone production. It is characterized by hypertension with low plasma renin and elevated aldosterone and often associated with hypokalemia. The two major causes of PA are unilateral aldosterone producing adenoma (APA) and bilateral adrenal hyperplasia, accounting together for ~95% of cases. In addition to the well-characterized effect of excess mineralocorticoids on blood pressure, high levels of aldosterone also have cardiovascular, renal, and metabolic consequences. Hence, long-term consequences of PA include increased risk of coronary artery disease, myocardial infarction, heart failure, and atrial fibrillation. Despite recent progress in the management of patients with PA, critical issues related to diagnosis, subtype differentiation, and treatment of non-surgically correctable forms still persist. A better understanding of the pathogenic mechanisms of the disease should lead to the identification of more reliable diagnostic and prognostic biomarkers for a more sensitive and specific screening and new therapeutic options. In this review, we will summarize our current knowledge on the molecular and cellular mechanisms of APA development. On one hand, we will discuss how various animal models have improved our understanding of the pathophysiology of excess aldosterone production. On the other hand, we will summarize the major advances made during the last few years in the genetics of APA due to transcriptomic studies and whole exome sequencing. The identification of recurrent and somatic mutations in genes coding for ion channels (KCNJ5 and CACNA1D) and ATPases (ATP1A1 and ATP2B3) allowed highlighting the central role of calcium signaling in autonomous aldosterone production by the adrenal.
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Affiliation(s)
- Sheerazed Boulkroun
- UMRS_970, Paris Cardiovascular Research Center, Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France
- University Paris Descartes, Sorbonne Paris Cité, Paris, France
- *Correspondence: Sheerazed Boulkroun, UMRS_970, Paris Cardiovascular Research Center (PARCC), Institut National de la Santé et de la Recherche Médicale (INSERM), 56 rue Leblanc, Paris 75015, France,
| | - Fabio Luiz Fernandes-Rosa
- UMRS_970, Paris Cardiovascular Research Center, Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France
- University Paris Descartes, Sorbonne Paris Cité, Paris, France
- Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service de Génétique, Paris, France
| | - Maria-Christina Zennaro
- UMRS_970, Paris Cardiovascular Research Center, Institut National de la Santé et de la Recherche Médicale (INSERM), Paris, France
- University Paris Descartes, Sorbonne Paris Cité, Paris, France
- Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges Pompidou, Service de Génétique, Paris, France
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75
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Martinez-Arguelles DB, Papadopoulos V. Mechanisms mediating environmental chemical-induced endocrine disruption in the adrenal gland. Front Endocrinol (Lausanne) 2015; 6:29. [PMID: 25788893 PMCID: PMC4349159 DOI: 10.3389/fendo.2015.00029] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 02/18/2015] [Indexed: 12/18/2022] Open
Abstract
Humans are continuously exposed to hundreds of man-made chemicals that pollute the environment in addition to multiple therapeutic drug treatments administered throughout life. Some of these chemicals, known as endocrine disruptors (EDs), mimic endogenous signals, thereby altering gene expression, influencing development, and promoting disease. Although EDs are eventually removed from the market or replaced with safer alternatives, new evidence suggests that early-life exposure leaves a fingerprint on the epigenome, which may increase the risk of disease later in life. Epigenetic changes occurring in early life in response to environmental toxicants have been shown to affect behavior, increase cancer risk, and modify the physiology of the cardiovascular system. Thus, exposure to an ED or combination of EDs may represent a first hit to the epigenome. Only limited information is available regarding the effect of ED exposure on adrenal function. The adrenal gland controls the stress response, blood pressure, and electrolyte homeostasis. This endocrine organ therefore has an important role in physiology and is a sensitive target of EDs. We review herein the effect of ED exposure on the adrenal gland with particular focus on in utero exposure to the plasticizer di(2-ethylehyl) phthalate. We discuss the challenges associated with identifying the mechanism mediating the epigenetic origins of disease and availability of biomarkers that may identify individual or population risks.
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Affiliation(s)
- Daniel B. Martinez-Arguelles
- Department of Medicine, Research Institute of the McGill University Health Centre, McGill University, Montreal, QC, Canada
- Department of Biochemistry, Research Institute of the McGill University Health Centre, McGill University, Montreal, QC, Canada
- *Correspondence: Daniel B. Martinez-Arguelles and Vassilios Papadopoulos, Research Institute of the McGill University Health Centre, Montreal General Hospital, 1650 Cedar Avenue, Room C10-148, Montréal, QC H3G 1A4, Canada e-mail: ;
| | - Vassilios Papadopoulos
- Department of Medicine, Research Institute of the McGill University Health Centre, McGill University, Montreal, QC, Canada
- Department of Biochemistry, Research Institute of the McGill University Health Centre, McGill University, Montreal, QC, Canada
- Department of Pharmacology and Therapeutics, Research Institute of the McGill University Health Centre, McGill University, Montreal, QC, Canada
- *Correspondence: Daniel B. Martinez-Arguelles and Vassilios Papadopoulos, Research Institute of the McGill University Health Centre, Montreal General Hospital, 1650 Cedar Avenue, Room C10-148, Montréal, QC H3G 1A4, Canada e-mail: ;
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76
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Lenzini L, Rossi GP. The molecular basis of primary aldosteronism: from chimeric gene to channelopathy. Curr Opin Pharmacol 2014; 21:35-42. [PMID: 25555247 DOI: 10.1016/j.coph.2014.12.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 12/01/2014] [Accepted: 12/05/2014] [Indexed: 11/19/2022]
Abstract
Primary aldosteronism (PA) is the most common endocrine cause of high blood pressure. Only a minority of the PA cases are familial and due to known (CYP11B2/CYP11B1 chimeric gene or mutations in the KCNJ5 gene) or unknown causes. In the most common sporadic cases the mechanisms by which the excess aldosterone production persists in spite of high blood pressure, sodium retention, suppression of the renin angiotensin system and low potassium levels, all factors that by themselves would be expected to shut off aldosterone production, were a puzzle for decades. Only recently the discovery of functional mutations and down-regulation of potassium channels provided some explanations. We herein reviewed these recent findings and their mechanistic implications. We also propose a clinical molecular classification of familial hyperaldosteronism, which can be important from the practical standpoint as it considers besides the molecular features also the responsiveness to treatment and the imaging features.
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Affiliation(s)
- Livia Lenzini
- Dept. of Medicine-DIMED, Internal Medicine 4, University of Padova, Italy
| | - Gian Paolo Rossi
- Dept. of Medicine-DIMED, Internal Medicine 4, University of Padova, Italy.
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77
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The role of K₂p channels in anaesthesia and sleep. Pflugers Arch 2014; 467:907-16. [PMID: 25482669 PMCID: PMC4428837 DOI: 10.1007/s00424-014-1654-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 11/11/2014] [Accepted: 11/12/2014] [Indexed: 12/20/2022]
Abstract
Tandem two-pore potassium channels (K2Ps) have widespread expression in the central nervous system and periphery where they contribute to background membrane conductance. Some general anaesthetics promote the opening of some of these channels, enhancing potassium currents and thus producing a reduction in neuronal excitability that contributes to the transition to unconsciousness. Similarly, these channels may be recruited during the normal sleep-wake cycle as downstream effectors of wake-promoting neurotransmitters such as noradrenaline, histamine and acetylcholine. These transmitters promote K2P channel closure and thus an increase in neuronal excitability. Our understanding of the roles of these channels in sleep and anaesthesia has been largely informed by the study of mouse K2P knockout lines and what is currently predicted by in vitro electrophysiology and channel structure and gating.
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78
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O'Kelly I. Endocytosis as a mode to regulate functional expression of two-pore domain potassium (K₂p) channels. Pflugers Arch 2014; 467:1133-42. [PMID: 25413469 PMCID: PMC4428836 DOI: 10.1007/s00424-014-1641-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 10/22/2014] [Accepted: 10/24/2014] [Indexed: 11/06/2022]
Abstract
Two-pore domain potassium (K2P) channels are implicated in an array of physiological and pathophysiological roles. As a result of their biophysical properties, these channels produce a background leak K+ current which has a direct effect on cellular membrane potential and activity. The regulation of potassium leak from cells through K2P channels is of critical importance to cell function, development and survival. Controlling the cell surface expression of these channels is one mode to regulate their function and is achieved through a balance between regulated channel delivery to and retrieval from the cell surface. Here, we explore the modes of retrieval of K2P channels from the plasma membrane and observe that K2P channels are endocytosed in both a clathrin-mediated and clathrin-independent manner. K2P channels use a variety of pathways and show altered internalisation and sorting in response to external cues. These pathways working in concert, equip the cell with a range of approaches to maintain steady state levels of channels and to respond rapidly should changes in channel density be required.
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Affiliation(s)
- Ita O'Kelly
- Human Development and Health, Centre for Human Development, Stem Cells and Regeneration, Faculty of Medicine, University of Southampton, Southampton, SO16 6YD, UK, I.M.O'
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79
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Abstract
CONTEXT Most syndromes with benign primary excess of a hormone show positive coupling of hormone secretion to size or proliferation in the affected hormone secretory tissue. Syndromes that lack this coupling seem rare and have not been examined for unifying features among each other. EVIDENCE ACQUISITION Selected clinical and basic features were analyzed from original reports and reviews. We examined indices of excess secretion of a hormone and indices of size of secretory tissue within the following three syndromes, each suggestive of uncoupling between these two indices: familial hypocalciuric hypercalcemia, congenital diazoxide-resistant hyperinsulinism, and congenital primary hyperaldosteronism type III (with G151E mutation of the KCNJ5 gene). EVIDENCE SYNTHESIS Some unifying features among the three syndromes were different from features present among common tumors secreting the same hormone. The unifying and distinguishing features included: 1) expression of hormone excess as early as the first days of life; 2) normal size of tissue that oversecretes a hormone; 3) diffuse histologic expression in the hormonal tissue; 4) resistance to treatment by subtotal ablation of the hormone-secreting tissue; 5) causation by a germline mutation; 6) low potential of the same mutation to cause a tumor by somatic mutation; and 7) expression of the mutated molecule in a pathway between sensing of a serum metabolite and secretion of hormone regulating that metabolite. CONCLUSION Some shared clinical and basic features of uncoupling of secretion from size in a hormonal tissue characterize three uncommon states of hormone excess. These features differ importantly from features of common hormonal neoplasm of that tissue.
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Affiliation(s)
- Stephen J Marx
- Genetics and Endocrinology Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892
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80
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Affiliation(s)
- Patrick E MacDonald
- University of Alberta, Department of Pharmacology and Alberta Diabetes Institute, Edmonton, Alberta, Canada T6G 2E1
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81
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Velarde-Miranda C, Gomez-Sanchez EP, Gomez-Sanchez CE. Regulation of aldosterone biosynthesis by the Kir3.4 (KCNJ5) potassium channel. Clin Exp Pharmacol Physiol 2014; 40:895-901. [PMID: 23829355 DOI: 10.1111/1440-1681.12151] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 06/30/2013] [Accepted: 07/01/2013] [Indexed: 11/30/2022]
Abstract
The G-protein-activated inwardly rectifying potassium channel Kir3.4 is expressed in the zona glomerulosa cell membrane and transports potassium out of the cell. Angiotensin II stimulation of aldosterone secretion is mediated, in part, by suppression of the transcription of KCNJ5, the gene coding for Kir3.4, and blocking channel activity. This results in membrane depolarization, mobilization of intracellular calcium, activation of the calcium-calmodulin pathway and increasing gene transcription of steroidogenic enzymes required for aldosterone secretion. In 40-60% of aldosterone-producing adenomas there is a somatic mutation in the region of the KCNJ5 gene that codes for the selectivity filter that decreases potassium selectivity, allowing sodium to leak into the cells, thus depolarizing the membrane and initiating events that result in increased aldosterone synthesis. The mechanism by which mutated KCNJ5 induces cell proliferation and adenoma formation remains unclear.
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Affiliation(s)
- Carolina Velarde-Miranda
- Research and Endocrine Service, GV (Sonny) Montgomery VA Medical Center, University of Mississippi Medical Center, Jackson, MS, USA; Division of Endocrinology, University of Mississippi Medical Center, Jackson, MS, USA
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82
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Potent and selective inhibitors of the TASK-1 potassium channel through chemical optimization of a bis-amide scaffold. Bioorg Med Chem Lett 2014; 24:3968-73. [PMID: 25017033 DOI: 10.1016/j.bmcl.2014.06.032] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 06/09/2014] [Accepted: 06/11/2014] [Indexed: 01/10/2023]
Abstract
TASK-1 is a two-pore domain potassium channel that is important to modulating cell excitability, most notably in the context of neuronal pathways. In order to leverage TASK-1 for therapeutic benefit, its physiological role needs better characterization; however, designing selective inhibitors that avoid the closely related TASK-3 channel has been challenging. In this study, a series of bis-amide derived compounds were found to demonstrate improved TASK-1 selectivity over TASK-3 compared to reported inhibitors. Optimization of a marginally selective hit led to analog 35 which displays a TASK-1 IC50=16 nM with 62-fold selectivity over TASK-3 in an orthogonal electrophysiology assay.
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83
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Hao X, Li X. The knockdown of TASK-1 channels improved the proliferation of N2A cells. J Mol Neurosci 2014; 55:314-7. [PMID: 24848104 DOI: 10.1007/s12031-014-0323-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 05/02/2014] [Indexed: 01/08/2023]
Abstract
Previous studies indicated that K(+) channels, such as voltage-gated Kv channels, were involved in the apoptosis and proliferation of neurons. In the experiments here, the small interfering RNAs (siRNAs) targeted against TASK-1, an acid-sensitive member of two-pore domain K(+) (K2P) channel family, were transfected into mouse neuroblastoma N2A cells. This treatment induced a reduction of messenger RNA (mRNA) level of TASK-1 by 61%. As a negative control, however, the transfection of scrambled siRNAs (scRNA) did not significantly affect the expression of TASK-1 in N2A cells. Furthermore, exposure to TASK-1-specific siRNAs (siTASK-1) for 48 h also substantially increased the proliferation rates of N2A cells by 25.8%, but no effect was observed in scRNA-treated cells. These data implied that TASK-1 channels may participate in the regulation of neuronal proliferation.
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Affiliation(s)
- Xuran Hao
- Department of Neuroscience, South-Central University for Nationalities, 182 Minyuan Road, 430074, Wuhan, China
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84
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Toncheva D, Mihailova-Hristova M, Vazharova R, Staneva R, Karachanak S, Dimitrov P, Simeonov V, Ivanov S, Balabanski L, Serbezov D, Malinov M, Stefanovic V, Čukuranović R, Polenakovic M, Jankovic-Velickovic L, Djordjevic V, Jevtovic-Stoimenov T, Plaseska-Karanfilska D, Galabov A, Djonov V, Dimova I. NGS nominated CELA1, HSPG2, and KCNK5 as candidate genes for predisposition to Balkan endemic nephropathy. BIOMED RESEARCH INTERNATIONAL 2014; 2014:920723. [PMID: 24949484 PMCID: PMC4052113 DOI: 10.1155/2014/920723] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 04/16/2014] [Accepted: 04/30/2014] [Indexed: 01/06/2023]
Abstract
Balkan endemic nephropathy (BEN) is a familial chronic tubulointerstitial disease with insidious onset and slow progression leading to terminal renal failure. The results of molecular biological investigations propose that BEN is a multifactorial disease with genetic predisposition to environmental risk agents. Exome sequencing of 22 000 genes with Illumina Nextera Exome Enrichment Kit was performed on 22 DNA samples (11 Bulgarian patients and 11 Serbian patients). Software analysis was performed via NextGene, Provean, and PolyPhen. The frequency of all annotated genetic variants with deleterious/damaging effect was compared with those of European populations. Then we focused on nonannotated variants (with no data available about them and not found in healthy Bulgarian controls). There is no statistically significant difference between annotated variants in BEN patients and European populations. From nonannotated variants with more than 40% frequency in both patients' groups, we nominated 3 genes with possible deleterious/damaging variants--CELA1, HSPG2, and KCNK5. Mutant genes (CELA1, HSPG2, and KCNK5) in BEN patients encode proteins involved in basement membrane/extracellular matrix and vascular tone, tightly connected to process of angiogenesis. We suggest that an abnormal process of angiogenesis plays a key role in the molecular pathogenesis of BEN.
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Affiliation(s)
- D. Toncheva
- Department of Medical Genetics, Medical University of Sofia, Zdrave Street 2, 1431 Sofia, Bulgaria
- Genomics Laboratory of Malinov Clinic, 1620 Sofia, Bulgaria
| | - M. Mihailova-Hristova
- Department of Medical Genetics, Medical University of Sofia, Zdrave Street 2, 1431 Sofia, Bulgaria
| | - R. Vazharova
- Genomics Laboratory of Malinov Clinic, 1620 Sofia, Bulgaria
| | - R. Staneva
- Department of Medical Genetics, Medical University of Sofia, Zdrave Street 2, 1431 Sofia, Bulgaria
| | - S. Karachanak
- Department of Medical Genetics, Medical University of Sofia, Zdrave Street 2, 1431 Sofia, Bulgaria
| | - P. Dimitrov
- Vratza District Hospital, 66 “Vtori Iuni” Boulevard, 3000 Vratza, Bulgaria
| | - V. Simeonov
- Faculty of Medicine, University of Nis, Univerzitetski trg 2, 18000 Nis, Serbia
| | - S. Ivanov
- Genomics Laboratory of Malinov Clinic, 1620 Sofia, Bulgaria
| | - L. Balabanski
- Genomics Laboratory of Malinov Clinic, 1620 Sofia, Bulgaria
| | - D. Serbezov
- Genomics Laboratory of Malinov Clinic, 1620 Sofia, Bulgaria
| | - M. Malinov
- Genomics Laboratory of Malinov Clinic, 1620 Sofia, Bulgaria
| | - V. Stefanovic
- Faculty of Medicine, University of Skopje, Macedonian Academy of Sciences and Arts, Bul. Krste Misirkov 2, P.O. Box 428, 1000 Skopje, Macedonia
| | - R. Čukuranović
- Faculty of Medicine, University of Skopje, Macedonian Academy of Sciences and Arts, Bul. Krste Misirkov 2, P.O. Box 428, 1000 Skopje, Macedonia
| | - M. Polenakovic
- Institute of Microbiology, Bulgarian Academy of Sciences, 26 Georgi Bonchev Street, 1113 Sofia, Bulgaria
| | - L. Jankovic-Velickovic
- Faculty of Medicine, University of Skopje, Macedonian Academy of Sciences and Arts, Bul. Krste Misirkov 2, P.O. Box 428, 1000 Skopje, Macedonia
| | - V. Djordjevic
- Faculty of Medicine, University of Skopje, Macedonian Academy of Sciences and Arts, Bul. Krste Misirkov 2, P.O. Box 428, 1000 Skopje, Macedonia
| | - T. Jevtovic-Stoimenov
- Institute of Microbiology, Bulgarian Academy of Sciences, 26 Georgi Bonchev Street, 1113 Sofia, Bulgaria
| | - D. Plaseska-Karanfilska
- Institute of Microbiology, Bulgarian Academy of Sciences, 26 Georgi Bonchev Street, 1113 Sofia, Bulgaria
| | - A. Galabov
- National Center of Public Health and Analyses, 15 Acad. Ivan Evst. Geshov Boulevard, 1431 Sofia, Bulgaria
| | - V. Djonov
- Institute of Anatomy, Bern University, Baltzerstrass 2, 3012 Bern, Switzerland
| | - I. Dimova
- Department of Medical Genetics, Medical University of Sofia, Zdrave Street 2, 1431 Sofia, Bulgaria
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Renigunta V, Fischer T, Zuzarte M, Kling S, Zou X, Siebert K, Limberg MM, Rinné S, Decher N, Schlichthörl G, Daut J. Cooperative endocytosis of the endosomal SNARE protein syntaxin-8 and the potassium channel TASK-1. Mol Biol Cell 2014; 25:1877-91. [PMID: 24743596 PMCID: PMC4055267 DOI: 10.1091/mbc.e13-10-0592] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
SNARE proteins can have functions unrelated to membrane fusion. The unassembled form of the SNARE protein syntaxin-8 interacts with the K+ channel TASK-1; both proteins are internalized via clathrin-mediated endocytosis in a cooperative manner. This is a novel mechanism for the control of endocytosis by cargo proteins. The endosomal SNARE protein syntaxin-8 interacts with the acid-sensitive potassium channel TASK-1. The functional relevance of this interaction was studied by heterologous expression of these proteins (and mutants thereof) in Xenopus oocytes and in mammalian cell lines. Coexpression of syntaxin-8 caused a fourfold reduction in TASK-1 current, a corresponding reduction in the expression of TASK-1 at the cell surface, and a marked increase in the rate of endocytosis of the channel. TASK-1 and syntaxin-8 colocalized in the early endosomal compartment, as indicated by the endosomal markers 2xFYVE and rab5. The stimulatory effect of the SNARE protein on the endocytosis of the channel was abolished when both an endocytosis signal in TASK-1 and an endocytosis signal in syntaxin-8 were mutated. A syntaxin-8 mutant that cannot assemble with other SNARE proteins had virtually the same effect as wild-type syntaxin-8. Total internal reflection fluorescence microscopy showed formation and endocytosis of vesicles containing fluorescence-tagged clathrin, TASK-1, and/or syntaxin-8. Our results suggest that the unassembled form of syntaxin-8 and the potassium channel TASK-1 are internalized via clathrin-mediated endocytosis in a cooperative manner. This implies that syntaxin-8 regulates the endocytosis of TASK-1. Our study supports the idea that endosomal SNARE proteins can have functions unrelated to membrane fusion.
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Affiliation(s)
- Vijay Renigunta
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Thomas Fischer
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Marylou Zuzarte
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Stefan Kling
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Xinle Zou
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Kai Siebert
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Maren M Limberg
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Susanne Rinné
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Niels Decher
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Günter Schlichthörl
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
| | - Jürgen Daut
- Institute of Physiology and Pathophysiology, Marburg University, 35037 Marburg, Germany
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86
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Lenzini L, Caroccia B, Campos AG, Fassina A, Belloni AS, Seccia TM, Kuppusamy M, Ferraro S, Skander G, Bader M, Rainey WE, Rossi GP. Lower expression of the TWIK-related acid-sensitive K+ channel 2 (TASK-2) gene is a hallmark of aldosterone-producing adenoma causing human primary aldosteronism. J Clin Endocrinol Metab 2014; 99:E674-82. [PMID: 24285684 DOI: 10.1210/jc.2013-2900] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
CONTEXT The molecular mechanisms of primary aldosteronism, a common cause of human hypertension, are unknown, but alterations of K(+) channels can play a key role. OBJECTIVE The objective of the study was to investigate the following: 1) the expression of the Twik-related acid-sensitive K(+) channels (TASK) in aldosterone producing adenomas (APAs); 2) the role of TASK-2 in aldosterone synthesis; and 3) the determinants of TASK-2-blunted expression in APAs. DESIGN We analyzed the transcriptome and the microRNA profiles of 32 consecutive APAs and investigated the protein expression and localization of TASK-2 in APA and adrenocortical cell lines (H295R and HAC15) using immunoblotting and confocal microscopy. The functional effect of TASK-2 blunted activity caused by a dominant-negative mutation on steroidogenic enzymes, and aldosterone production was also assessed. TASK-2 regulation by selected microRNA was studied by a luciferase assay. RESULTS TASK-2 was consistently less expressed at the transcript and protein levels in APAs than in the normal human adrenal cortex. H295R cell transfection with a TASK-2 dominant-negative mutant construct significantly increased the aldosterone production by 153% and the gene expression of aldosterone synthase (CYP11B2, gene expression fold change 3.1 vs control, P < .05) and the steroidogenic acute regulatory protein (gene expression fold change 1.8 vs control, P < .05). Two microRNAs, hsa-miR-23 and hsa-miR-34, were found to decrease the TASK-2 expression by binding to the 3' untranslated region of the TASK-2 gene. CONCLUSIONS The TASK-2 channel lower expression represents a hallmark of APA and is associated with a higher expression of hsa-miR-23 and hsa-miR-34. The ensuing blunted TASK-2 activity increased the production of aldosterone in vitro and the expression of steroidogenic acute regulatory protein and CYP11B2. Hence, the lower expression of TASK-2 channel in APA cells can explain high aldosterone secretion in human primary aldosteronism despite the suppression of angiotensin II, hypertension, and hypokalemia.
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Affiliation(s)
- Livia Lenzini
- Internal Medicine 4 (L.L., B.C., A.G.C., T.M.S., M.K., S.F., G.S., G.P.R.) and Surgical Pathology and Cytopathology Unit (A.F.), Department of Medicine, Department of Medicine, Section of Human Anatomy and Physiology (A.S.B.), Department of Molecular Medicine, University of Padua, 35128 Padua, Italy; Max-Delbrück-Center for Molecular Medicine (M.B.), 13092 Berlin, Germany; and Department of Molecular and Integrative Physiology (W.E.R.), University of Michigan, Ann Arbor, Michigan 48109
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87
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Affiliation(s)
- Celso E Gomez-Sanchez
- Endocrine Section, G.V. (Sonny) Montgomery VA Medical Center, and University of Mississippi Medical Center, Jackson, Mississippi 39216
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88
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Tauber P, Penton D, Stindl J, Humberg E, Tegtmeier I, Sterner C, Beuschlein F, Reincke M, Barhanin J, Bandulik S, Warth R. Pharmacology and pathophysiology of mutated KCNJ5 found in adrenal aldosterone-producing adenomas. Endocrinology 2014; 155:1353-62. [PMID: 24506072 DOI: 10.1210/en.2013-1944] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Somatic mutations of the potassium channel KCNJ5 are found in 40% of aldosterone producing adenomas (APAs). APA-related mutations of KCNJ5 lead to a pathological Na(+) permeability and a rise in cytosolic Ca(2+), the latter presumably by depolarizing the membrane and activating voltage-gated Ca(2+) channels. The aim of this study was to further investigate the effects of mutated KCNJ5 channels on intracellular Na(+) and Ca(2+) homeostasis in human adrenocortical NCI-H295R cells. Expression of mutant KCNJ5 led to a 2-fold increase in intracellular Na(+) and, in parallel, to a substantial rise in intracellular Ca(2+). The increase in Ca(2+) appeared to be caused by activation of voltage-gated Ca(2+) channels and by an impairment of Ca(2+) extrusion by Na(+)/Ca(2+) exchangers. The mutated KCNJ5 exhibited a pharmacological profile that differed from the one of wild-type channels. Mutated KCNJ5 was less Ba(2+) and tertiapin-Q sensitive but was inhibited by blockers of Na(+) and Ca(2+)-transporting proteins, such as verapamil and amiloride. The clinical use of these drugs might influence aldosterone levels in APA patients with KCNJ5 mutations. This might implicate diagnostic testing of APAs and could offer new therapeutic strategies.
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Affiliation(s)
- P Tauber
- Medical Cell Biology (P.T., J.S., E.H., I.T., C.S., S.B., R.W.), University of Regensburg, 93053 Regensburg, Germany; Laboratoire de PhysioMédecine Moléculaire (D.P., J.B.), Centre National de la Recherche Scientifique, and Université de Nice Sophia Antipolis, FRE3472-Laboratoire de PhysioMédecine Moléculaire, 06108 Nice Cedex, France; Laboratories of Excellence, Ion Channel Science and Therapeutics (D.P., J.B.), France; and Medizinische Klinik und Poliklinik IV (F.B., M.R.), Ludwig-Maximilians-Universität, 80336 Munich, Germany
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89
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Spyroglou A, Bozoglu T, Rawal R, De Leonardis F, Sterner C, Boulkroun S, Benecke AG, Monti L, Zennaro MC, Petersen AK, Döring A, Rossi A, Bidlingmaier M, Warth R, Gieger C, Reincke M, Beuschlein F. Diastrophic dysplasia sulfate transporter (SLC26A2) is expressed in the adrenal cortex and regulates aldosterone secretion. Hypertension 2014; 63:1102-9. [PMID: 24591336 DOI: 10.1161/hypertensionaha.113.02504] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Elucidation of the molecular mechanisms leading to autonomous aldosterone secretion is a prerequisite to define potential targets and biomarkers in the context of primary aldosteronism. After a genome-wide association study with subjects from the population-based Cooperative Health Research in the Region of Augsburg F4 survey, we observed a highly significant association (P=6.78×10(-11)) between the aldosterone to renin ratio and a locus at 5q32. Hypothesizing that this locus may contain genes of relevance for the pathogenesis of primary aldosteronism, we investigated solute carrier family 26 member 2 (SLC26A2), a protein with known transport activity for sulfate and other cations. Within murine tissues, adrenal glands showed the highest expression levels for SLC26A2, which was significantly downregulated on in vivo stimulation with angiotensin II and potassium. SLC26A2 expression was found to be significantly lower in aldosterone-producing adenomas in comparison with normal adrenal glands. In adrenocortical NCI-H295R cells, specific knockdown of SLC26A2 resulted in a highly significant increase in aldosterone secretion. Concomitantly, expression of steroidogenic enzymes, as well as upstream effectors including transcription factors such as NR4A1, CAMK1, and intracellular Ca(2+) content, was upregulated in knockdown cells. To substantiate further these findings in an SLC26A2 mutant mouse model, aldosterone output proved to be increased in a sex-specific manner. In summary, these findings point toward a possible effect of SLC26A2 in the regulation of aldosterone secretion potentially involved in the pathogenesis of primary aldosteronism.
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Affiliation(s)
- Ariadni Spyroglou
- Endocrine Research Unit, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Ziemssenstr. 1, D-80336 Munich, Germany.
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90
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McManus F, Alvarez-Madrazo S, Connell JM. Progress in the identification of responsible genes and molecular mechanisms in primary aldosteronism. Expert Rev Endocrinol Metab 2014; 9:163-174. [PMID: 30743758 DOI: 10.1586/17446651.2014.883276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Aldosterone, the mineralocorticoid hormone, plays an important role in blood regulation. Autonomous secretion of aldosterone is known as primary aldosteronism (PA), the most common cause of secondary hypertension. PA comprises a group of heterogenous disorders which makes their classification and management challenging. With the advent of the genomic era several germline and somatic mutations have been identified that are involved in the pathogenesis of primary aldosteronism. This article will review our current knowledge of the genetic mechanisms of familial hyperaldosterism, somatic mutations in genes encoding electrolyte channels and other potential genetic mechanisms implicated in the dysregulation of aldosterone production from in vitro and animal models. There is potential for novel targeted therapies and diagnosis for subsets of patient. The challenges to achieve them are highlighted in this review.
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Affiliation(s)
- Frances McManus
- a Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | - Samantha Alvarez-Madrazo
- a Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, UK
| | - John M Connell
- b Medical Research Institute, College of Medicine, Dentistry and Nursing, University of Dundee, Dundee DD1 9SY, UK
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91
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Gomez-Sanchez CE, Oki K. Minireview: potassium channels and aldosterone dysregulation: is primary aldosteronism a potassium channelopathy? Endocrinology 2014; 155:47-55. [PMID: 24248457 PMCID: PMC5398635 DOI: 10.1210/en.2013-1733] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Primary aldosteronism is the most common form of secondary hypertension and has significant cardiovascular consequences. Aldosterone-producing adenomas (APAs) are responsible for half the cases of primary aldosteronism, and about half have mutations of the G protein-activated inward rectifying potassium channel Kir3.4. Under basal conditions, the adrenal zona glomerulosa cells are hyperpolarized with negative resting potentials determined by membrane permeability to K(+) mediated through various K(+) channels, including the leak K(+) channels TASK-1, TASK-3, and Twik-Related Potassium Channel 1, and G protein inward rectifying potassium channel Kir3.4. Angiotensin II decreases the activity of the leak K(+) channels and Kir3.4 channel and decreases the expression of the Kir3.4 channel, resulting in membrane depolarization, increased intracellular calcium, calcium-calmodulin pathway activation, and increased expression of cytochrome P450 aldosterone synthase (CYP11B2), the last enzyme for aldosterone production. Somatic mutations of the selectivity filter of the Kir3.4 channel in APA results in loss of selectivity for K(+) and entry of sodium, resulting in membrane depolarization, calcium mobilization, increased CYP11B2 expression, and hyperaldosteronism. Germ cell mutations cause familial hyperaldosteronism type 3, which is associated with adrenal zona glomerulosa hyperplasia, rather than adenoma. Less commonly, somatic mutations of the sodium-potassium ATPase, calcium ATPase, or the calcium channel calcium channel voltage-dependent L type alpha 1D have been found in some APAs. The regulation of aldosterone secretion is exerted to a significant degree by activation of membrane K(+) and calcium channels or pumps, so it is not surprising that the known causes of disorders of aldosterone secretion in APA have been channelopathies, which activate mechanisms that increase aldosterone synthesis.
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Affiliation(s)
- Celso E Gomez-Sanchez
- Endocrinology Division (C.E.G.-S.), G. V. (Sonny) Montgomery Veterans Affairs Medical Center and University of Mississippi Medical Center, Jackson, Mississippi 39216; and Department of Endocrinology and Diabetes (K.O.), Hiroshima University Hospital, Hiroshima 734-8551, Japan
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92
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Ip JCY, Pang TCY, Pon CK, Zhao JT, Sywak MS, Gill AJ, Soon PS, Sidhu SB. Mutations in KCNJ5 determines presentation and likelihood of cure in primary hyperaldosteronism. ANZ J Surg 2013; 85:279-83. [PMID: 24274318 DOI: 10.1111/ans.12470] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/20/2013] [Indexed: 02/04/2023]
Abstract
INTRODUCTION Primary hyperaldosteronism (PA) is a common cause of secondary hypertension. Two recurrent mutations (G151R and L168R) in the potassium channel gene KCNJ5 have been identified that affect the Kir3.4 potassium channel found in the cells of the zona glomerulosa of the adrenal gland. The aim of this study was to determine the prevalence of KCNJ5 mutations in an Australian cohort of patients and to correlate these findings with clinical outcome data, in order to describe the clinical impact on patients who harbour this mutation. METHODS Direct Sanger sequencing for KCNJ5 on DNA from adrenal tumour tissue of 83 patients with PA in a cohort study was undertaken and mutation status correlated with clinical outcome data. RESULTS Seventy-one of 83 patients (86%) had adrenocortical adenomas and 12 patients (14%) had bilateral adrenal hyperplasia. A total of 34 (41%) patients were found to have heterozygous somatic mutations in KCNJ5, G151R and L168R. No germ line mutations were identified. Patients with mutations were predominately female (68% versus 49%) and significantly younger at presentation (48 versus 55 years). When correlated with clinical data, our results demonstrated that patients with KCNJ5 mutations were more likely to be cured following surgery without the requirement for ongoing medications. CONCLUSIONS Our findings in a large Australian cohort show that patients with mutations in KCNJ5 present earlier with the signs and symptoms of PA benefit from surgical intervention. Moreover, our results highlight the importance of a thorough workup and management plan for younger patients who present with hypertension.
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Affiliation(s)
- Julian C Y Ip
- Cancer Genetics, Kolling Institute of Medical Research, Royal North Shore Hospital, Sydney, New South Wales, Australia; Faculty of Medicine, Northern Clinical School, The University of Sydney, Sydney, New South Wales, Australia
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93
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Berthon A, Drelon C, Ragazzon B, Boulkroun S, Tissier F, Amar L, Samson-Couterie B, Zennaro MC, Plouin PF, Skah S, Plateroti M, Lefèbvre H, Sahut-Barnola I, Batisse-Lignier M, Assié G, Lefrançois-Martinez AM, Bertherat J, Martinez A, Val P. WNT/β-catenin signalling is activated in aldosterone-producing adenomas and controls aldosterone production. Hum Mol Genet 2013; 23:889-905. [PMID: 24087794 DOI: 10.1093/hmg/ddt484] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Primary aldosteronism (PA) is the main cause of secondary hypertension, resulting from adrenal aldosterone-producing adenomas (APA) or bilateral hyperplasia. Here, we show that constitutive activation of WNT/β-catenin signalling is the most frequent molecular alteration found in 70% of APA. We provide evidence that decreased expression of the WNT inhibitor SFRP2 may be contributing to deregulated WNT signalling and APA development in patients. This is supported by the demonstration that mice with genetic ablation of Sfrp2 have increased aldosterone production and ectopic differentiation of zona glomerulosa cells. We further show that β-catenin plays an essential role in the control of basal and Angiotensin II-induced aldosterone secretion, by activating AT1R, CYP21 and CYP11B2 transcription. This relies on both LEF/TCF-dependent activation of AT1R and CYP21 regulatory regions and indirect activation of CYP21 and CYP11B2 promoters, through increased expression of the nuclear receptors NURR1 and NUR77. Altogether, these data show that aberrant WNT/β-catenin activation is associated with APA development and suggest that WNT pathway may be a good therapeutic target in PA.
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Affiliation(s)
- Annabel Berthon
- Clermont Université, Université Blaise Pascal, GReD, BP 10448, F-63000 Clermont-Ferrand, France
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94
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Bandulik S, Tauber P, Penton D, Schweda F, Tegtmeier I, Sterner C, Lalli E, Lesage F, Hartmann M, Barhanin J, Warth R. Severe hyperaldosteronism in neonatal Task3 potassium channel knockout mice is associated with activation of the intraadrenal renin-angiotensin system. Endocrinology 2013; 154:2712-22. [PMID: 23698720 DOI: 10.1210/en.2013-1101] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Task3 K(+) channels are highly expressed in the adrenal cortex and contribute to the angiotensin II and K(+) sensitivity of aldosterone-producing glomerulosa cells. Adult Task3(-/-) mice display a partially autonomous aldosterone secretion, subclinical hyperaldosteronism, and salt-sensitive hypertension. Here, we investigated the age dependence of the adrenal phenotype of Task3(-/-) mice. Compared with adults, newborn Task3(-/-) mice displayed a severe adrenal phenotype with strongly increased plasma levels of aldosterone, corticosterone, and progesterone. This adrenocortical dysfunction was accompanied by a modified gene expression profile. The most strongly up-regulated gene was the protease renin. Real-time PCR corroborated the strong increase in adrenal renin expression, and immunofluorescence revealed renin-expressing cells in the zona fasciculata. Together with additional factors, activation of the local adrenal renin system is probably causative for the severely disturbed steroid hormone secretion of neonatal Task3(-/-) mice. The changes in gene expression patterns of neonatal Task3(-/-) mice could also be relevant for other forms of hyperaldosteronism.
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Affiliation(s)
- Sascha Bandulik
- Department of Medical Cell Biology, University of Regensburg, 93053 Regensburg, Germany.
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Abstract
Aldosterone plays a major role in the regulation of sodium and potassium homeostasis and blood pressure. More recently, aldosterone has emerged as a key hormone mediating end organ damage. In extreme cases, dysregulated aldosterone production leads to primary aldosteronism (PA), the most common form of secondary hypertension. However, even within the physiological range, high levels of aldosterone are associated with an increased risk of developing hypertension over time. PA represents the most common and curable form of hypertension, with a prevalence that increases with the severity of hypertension. Although genetic causes underlying glucocorticoid-remediable aldosteronism, one of the three Mendelian forms of PA, were established some time ago, somatic and inherited mutations in the potassium channel GIRK4 have only recently been implicated in the formation of aldosterone-producing adenoma (APA) and in familial hyperaldosteronism type 3. Moreover, recent findings have shown somatic mutations in two additional genes, involved in maintaining intracellular ionic homeostasis and cell membrane potential, in a subset of APAs. This review summarizes our current knowledge on the genetic determinants that contribute to variations in plasma aldosterone and renin levels in the general population and the genetics of familial and sporadic PA. Various animal models that have significantly improved our understanding of the pathophysiology of excess aldosterone production are also discussed. Finally, we outline the cardiovascular, renal, and metabolic consequences of mineralocorticoid excess beyond blood pressure regulation.
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96
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Abstract
PURPOSE OF REVIEW To summarize and discuss data from recent studies implicating mutations in potassium channel genes in the pathogenesis of primary aldosteronism. RECENT FINDINGS Potassium channel gene variants are associated with the primary aldosteronism phenotype in animals (Kcnma1, TASK-1, and TASK-3) and humans (HERG and KCNJ5). Germline KCNJ5 mutations cause bilateral, familial primary aldosteronism with variable severity and genotype:phenotype correlations. Somatic KCNJ5 mutations occur in approximately 40% of aldosterone-producing adenomas, and are associated with younger age, female sex, more severe primary aldosteronism, lack of responsiveness of plasma aldosterone to upright posture, and zona fasciculata histology. Of five so far described, G151R and L168R are by far the most common. KCNJ5 mutations lead to reduced K⁺/Na⁺ channel selectivity and Na⁺ influx, predisposing to cell membrane depolarization, increased calcium influx, increased expression of genes promoting aldosterone synthesis, and increased aldosterone production by adrenocortical cells. How they lead to adrenal cell proliferation and tumor development is less well understood. SUMMARY These findings shed considerable light on the pathophysiology of primary aldosteronism with the potential to lead to new diagnostic approaches and treatments.
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Affiliation(s)
- Michael Stowasser
- Endocrine Hypertension Research Centre, University of Queensland School of Medicine, Greenslopes and Princess Alexandra Hospitals, Brisbane, Australia.
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97
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Abstract
Arterial hypertension is a major cardiovascular risk factor that affects between 10 and 40% of the population in industrialized countries. Primary aldosteronism (PA) is the most common form of secondary hypertension with an estimated prevalence of around 10% in referral centers and 4% in a primary care setting. Despite its high prevalence until recently, the underlying genetic and molecular basis of this common disease had remained largely obscure. Over the past decade, a number of insights have been achieved that have relied on in vitro cellular systems, wild-type and genetically modified in vivo models, as well as clinical studies in well-characterized patient populations. This progress has been made possible by a number of independent technical developments including that of specific hormone assays that allow measurement in small sample volumes as well as genetic techniques that enable high-throughput sequencing of a large number of samples. Furthermore, animal models have provided important insights into the physiology of aldosterone regulation that have served as a starting point for investigation of mechanisms involved in autonomous aldosterone secretion. Finally, national and international networks that have built up registries and biobanks have been instrumental in fostering translational research endeavors in PA. Therefore, it is to be expected that in the near future, further pathophysiological mechanisms that result in autonomous aldosterone secretion will be unraveled.
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Affiliation(s)
- Felix Beuschlein
- Endocrine Research Unit, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Ziemssenstrasse 1, D-80336 Munich, Germany.
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Mulatero P, Monticone S, Rainey WE, Veglio F, Williams TA. Role of KCNJ5 in familial and sporadic primary aldosteronism. Nat Rev Endocrinol 2013; 9:104-12. [PMID: 23229280 DOI: 10.1038/nrendo.2012.230] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Primary aldosteronism is characterised by the dysregulation of aldosterone production and comprises both sporadic forms, caused by an aldosterone-producing adenoma or bilateral adrenal hyperplasia, and familial forms (familial hyperaldosteronism types I, II and III). The two principal physiological regulators of aldosterone synthesis are angiotensin II and serum K(+), which reverse the high resting K(+) conductance and hyperpolarized membrane potential of adrenal glomerulosa cells. The resulting membrane depolarization causes the opening of voltage-gated Ca(2+) channels and an increase in intracellular Ca(2+) that stimulates aldosterone biosynthesis. Point mutations in the KCNJ5 gene, which encodes the G-protein-activated inward rectifier K(+) channel 4 (GIRK4), have been implicated in the pathogenesis of both sporadic and familial forms of primary aldosteronism. These mutations interfere with the selectivity filter of GIRK4 causing Na(+) entry, cell depolarization and Ca(2+) channel opening, resulting in constitutive aldosterone production. Seven families with familial hyperaldosteronism caused by KCNJ5 germline mutations have so far been described, and multicentre studies have reported KCNJ5 mutations in approximately 40% of sporadic aldosterone-producing adenomas. Herein, we review the role of GIRK4 in adrenal pathophysiology and provide an overview of the clinical and biochemical phenotypes resulting from KCNJ5 mutations in patients with sporadic and familial primary aldosteronism.
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Affiliation(s)
- Paolo Mulatero
- University of Torino, Department of Medical Sciences, Division of Internal Medicine and Hypertension, Italy. paolo.mulatero@ unito.it
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Li NF, Li HJ, Zhang DL, Zhang JH, Yao XG, Wang HM, Abulikemu S, Zhou KM, Zhang XY. Genetic variations in the KCNJ5 gene in primary aldosteronism patients from Xinjiang, China. PLoS One 2013; 8:e54051. [PMID: 23382865 PMCID: PMC3561325 DOI: 10.1371/journal.pone.0054051] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 12/05/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Primary aldosteronism (PA) is the most common endocrine form of secondary hypertension, and one of the most common subtypes of sporadic PA is aldosterone-producing adenoma (APA). Recently, two somatic mutations of the KCNJ5 gene were implicated in APA, and two germline mutations were associated with familial hyperaldosteronism III. OBJECTIVES This case-control study was designed to investigate the relationship between genetic variations in the KCNJ5 gene and sporadic PA patients in Xinjiang, China. METHODS Five common single nucleotide polymorphisms (SNPs) of the KCNJ5 gene (rs6590357, rs4937391, rs3740835, rs2604204, and rs11221497) were detected in patients with sporadic PA (n = 235) and essential hypertension (EH; n=913) by the TaqMan polymerase chain reaction method. RESULTS The EH group and the PA group showed significant differences in the distributions of genotypes and alleles of rs4937391 and rs2604204 in total and male subjects (P<0.05), as well as rs3740835 in male subjects (P<0.05). However, only the association between the rs2604204 genotype and male sporadic PA remained significant after Bonferroni's correction (P<0.01). Furthermore, logistic regression analysis demonstrated that the CC genotype of rs2604204 was a risk factor for male patients with sporadic PA, after adjusting for age and body mass index (odds ratio=2.228, 95% CI: 1.300-3.819, P=0.004). CONCLUSION The genetic variant rs2604204 of KCNJ5 is associated with sporadic PA in Chinese males, suggesting that KCNJ5 may be involved in the pathogenesis of sporadic PA in these particular patients.
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Affiliation(s)
- Nan-Fang Li
- The Center of Hypertension of the People's Hospital of Xinjiang Uygur Autonomous Region, The Center of Diagnosis, Treatment and Research of Hypertension in Xinjiang, Urumqi, China.
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100
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Changes in the hepatic mitochondrial and membrane proteome in mice fed a non-alcoholic steatohepatitis inducing diet. J Proteomics 2013; 80:107-22. [PMID: 23313215 DOI: 10.1016/j.jprot.2012.12.027] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 11/30/2012] [Accepted: 12/17/2012] [Indexed: 12/20/2022]
Abstract
Non-alcoholic steatohepatitis (NASH) accounts for a large proportion of cryptic cirrhosis in the Western societies. Nevertheless, we lack a deeper understanding of the underlying pathomolecular processes, particularly those preceding hepatic inflammation and fibrosis. In order to gain novel insights into early NASH-development from the first appearance of proteomic alterations to the onset of hepatic inflammation and fibrosis, we conducted a time-course analysis of proteomic changes in liver mitochondria and membrane-enriched fractions of female C57Bl/6N mice fed either a mere steatosis or NASH inducing diet. This data was complemented by quantitative measurements of hepatic glycerol-containing lipids, cholesterol and intermediates of the methionine cycle. Aside from energy metabolism and stress response proteins, enzymes of the urea cycle and methionine metabolism were found regulated. Alterations in the methionine cycle occur early in disease progression preceding molecular signs of inflammation. Proteins that hold particular promise in the early distinction between benign steatosis and NASH are methyl-transferase Mettl7b, the glycoprotein basigin and the microsomal glutathione-transferase.
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