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1.
Horm Metab Res ; 2020 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32289837

RESUMO

The CYP11B2 enzyme is the terminal enzyme in the biosynthesis of aldosterone. Immunohistochemistry using antibodies against CYP11B2 defines cells of the adrenal ZG that synthesize aldosterone. CYP11B2 expression is normally stimulated by angiotensin II, but becomes autonomous in primary hyperaldosteronism, in most cases driven by recently discovered somatic mutations of ion channels or pumps. Cells expressing CYP11B2 in young normal humans form a continuous band beneath the adrenal capsule; in older individuals they form discrete clusters, aldosterone-producing cell clusters (APCC), surrounded by non-aldosterone producing cells in the outer layer of the adrenal gland. Aldosterone-producing adenomas may exhibit a uniform or heterogeneous expression of CYP11B2. APCC frequently persist in the adrenal with an aldosterone-producing adenoma suggesting autonomous CYP11B2 expression in these cells as well. This was confirmed by finding known mutations that drive aldosterone production in adenomas in the APCC of clinically normal people. Unilateral aldosteronism may also be due to multiple CYP11B2-expressing nodules of various sizes or a continuous band of hyperplastic ZG cells expressing CYP11B2. Use of CYP11B2 antibodies to identify areas for sequencing has greatly facilitated the detection of aldosterone-driving mutations.

3.
J Clin Invest ; 130(1): 83-93, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31738186

RESUMO

The mineralocorticoid aldosterone is produced in the adrenal zona glomerulosa (ZG) under the control of the renin-angiotensin II (AngII) system. Primary aldosteronism (PA) results from renin-independent production of aldosterone and is a common cause of hypertension. PA is caused by dysregulated localization of the enzyme aldosterone synthase (Cyp11b2), which is normally restricted to the ZG. Cyp11b2 transcription and aldosterone production are predominantly regulated by AngII activation of the Gq signaling pathway. Here, we report the generation of transgenic mice with Gq-coupled designer receptors exclusively activated by designer drugs (DREADDs) specifically in the adrenal cortex. We show that adrenal-wide ligand activation of Gq DREADD receptors triggered disorganization of adrenal functional zonation, with induction of Cyp11b2 in glucocorticoid-producing zona fasciculata cells. This result was consistent with increased renin-independent aldosterone production and hypertension. All parameters were reversible following termination of DREADD-mediated Gq signaling. These findings demonstrate that Gq signaling is sufficient for adrenocortical aldosterone production and implicate this pathway in the determination of zone-specific steroid production within the adrenal cortex. This transgenic mouse also provides an inducible and reversible model of hyperaldosteronism to investigate PA therapeutics and the mechanisms leading to the damaging effects of aldosterone on the cardiovascular system.

4.
Hypertension ; 75(2): 492-499, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31865789

RESUMO

The endoplasmic reticulum (ER) plays a pivotal role in syntheses of proteins and steroid hormones and regulation of intracellular Ca2+ level. We aimed to investigate ER-associated genes in aldosterone-producing adenomas (APAs) and clarify their effect on aldosterone production. Microarray analysis targeting 288 ER-associated genes was conducted using nonfunctioning adrenocortical adenomas (n=5) and APAs (n=19). Immunohistochemistry and quantitative polymerase chain reaction analyses were performed with 13 nonfunctioning adrenocortical adenoma and 48 APA samples. Functional studies were performed with human adrenocortical carcinoma (HAC15) cells, some of which were genetically modified using lentiviruses. The ER chaperone calmegin (CLGN) was the most highly expressed ER-associated gene in APAs relative to nonfunctioning adrenocortical adenomas. Analysis with quantitative polymerase chain reaction revealed CLGN to be 9.5-fold upregulated in APAs relative to nonfunctioning adrenocortical adenomas. There were no differences among different APA genotypes affecting aldosterone production. Immunohistochemistry analysis revealed that CLGN was strongly expressed in APAs and aldosterone-producing cell clusters. Angiotensin II stimulation or KCNJ5 T158A overexpression in HAC15 cells did not affect CLGN mRNA levels. CLGN overexpression in HAC15 cells increased aldosterone levels but did not stimulate CYP11B2 mRNA levels. Pathway and gene ontology analyses using RNA sequencing results showed that tRNA aminoacyl metabolism was the most enriched pathway in CLGN-overexpressing cells. CYP11B2 (aldosterone synthase) and HSD3B2 (3 beta-hydroxysteroid dehydrogenase/delta 5->4-isomerase type 2) protein expression were more abundant in CLGN-overexpressing cells. CLGN knockdown using CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeat-associated 9) method in HAC15 cells that carry the KCNJ5 mutation did not affect aldosterone production. To summarize, CLGN was upregulated and associated with aldosterone production via translational regulation of CYP11B2 in APAs.

5.
Front Physiol ; 10: 1324, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31736768

RESUMO

Acute skeletal muscle injury is followed by a temporal response of immune cells, fibroblasts, and muscle progenitor cells within the muscle microenvironment to restore function. These same cell types are repeatedly activated in muscular dystrophy from chronic muscle injury, but eventually, the regenerative portion of the cycle is disrupted and fibrosis replaces degenerated muscle fibers. Mineralocorticoid receptor (MR) antagonist drugs have been demonstrated to increase skeletal muscle function, decrease fibrosis, and directly improve membrane integrity in muscular dystrophy mice, and therefore are being tested clinically. Conditional knockout of MR from muscle fibers in muscular dystrophy mice also improves skeletal muscle function and decreases fibrosis. The mechanism of efficacy likely results from blocking MR signaling by its endogenous agonist aldosterone, being produced at high local levels in regions of muscle damage by infiltrating myeloid cells. Since chronic and acute injuries share the same cellular processes to regenerate muscle, and MR antagonists are clinically used for a wide variety of conditions, it is crucial to define the role of MR signaling in normal muscle repair after injury. In this study, we performed acute injuries using barium chloride injections into tibialis anterior muscles both in myofiber MR conditional knockout mice on a wild-type background (MRcko) and in MR antagonist-treated wild-type mice. Steps of the muscle regeneration response were analyzed at 1, 4, 7, or 14 days after injury. Presence of the aldosterone synthase enzyme was also assessed during the injury repair process. We show for the first time aldosterone synthase localization in infiltrating immune cells of normal skeletal muscle after acute injury. MRcko mice had an increased muscle area infiltrated by aldosterone synthase positive myeloid cells compared to control injured animals. Both MRcko and MR antagonist treatment stabilized damaged myofibers and increased collagen infiltration or compaction at 4 days post-injury. MR antagonist treatment also led to reduced myofiber size at 7 and 14 days post-injury. These data support that MR signaling contributes to the normal muscle repair process following acute injury. MR antagonist treatment delays muscle fiber growth, so temporary discontinuation of these drugs after a severe muscle injury could be considered.

6.
Sci Rep ; 9(1): 14677, 2019 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-31605007

RESUMO

Primary aldosteronism (PA) is the most frequent form of secondary arterial hypertension. Mutations in different genes increase aldosterone production in PA, but additional mechanisms may contribute to increased cell proliferation and aldosterone producing adenoma (APA) development. We performed transcriptome analysis in APA and identified retinoic acid receptor alpha (RARα) signaling as a central molecular network involved in nodule formation. To understand how RARα modulates adrenal structure and function, we explored the adrenal phenotype of male and female Rarα knockout mice. Inactivation of Rarα in mice led to significant structural disorganization of the adrenal cortex in both sexes, with increased adrenal cortex size in female mice and increased cell proliferation in males. Abnormalities of vessel architecture and extracellular matrix were due to decreased Vegfa expression and modifications in extracellular matrix components. On the molecular level, Rarα inactivation leads to inhibition of non-canonical Wnt signaling, without affecting the canonical Wnt pathway nor PKA signaling. Our study suggests that Rarα contributes to the maintenance of normal adrenal cortex structure and cell proliferation, by modulating Wnt signaling. Dysregulation of this interaction may contribute to abnormal cell proliferation, creating a propitious environment for the emergence of specific driver mutations in PA.

7.
Hypertension ; 74(4): 809-816, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31446799

RESUMO

Aldosterone-producing adenomas with somatic mutations in the KCNJ5 G-protein-coupled inwardly rectifying potassium channel are a cause of primary aldosteronism. These mutations drive aldosterone excess, but their role in cell growth is undefined. Our objective was to determine the role of KCNJ5 mutations in adrenal cell proliferation and apoptosis. The Ki67 proliferative index was positively correlated with adenoma diameter in aldosterone-producing adenomas with a KCNJ5 mutation (r=0.435, P=0.007), a negative correlation was noted in adenomas with no mutation detected (r=-0.548, P=0.023). Human adrenocortical cell lines were established with stable expression of cumate-inducible wild-type or mutated KCNJ5. Increased cell proliferation was induced by low-level induction of KCNJ5-T158A expression compared with control cells (P=0.009), but increased induction ablated this difference. KCNJ5-G151R displayed no apparent proliferative effect, but KCNJ5-G151E and L168R mutations each resulted in decreased cell proliferation (difference P<0.0001 from control cells, both comparisons). Under conditions tested, T158A had no effect on apoptosis, but apoptosis increased with expression of G151R (P<0.0001), G151E (P=0.008), and L168R (P<0.0001). We generated a specific KCNJ5 monoclonal antibody which was used in immunohistochemistry to demonstrate strong KCNJ5 expression in adenomas without a KCNJ5 mutation and in the zona glomerulosa adjacent to adenomas irrespective of genotype as well as in aldosterone-producing cell clusters. Double immunofluorescence staining for KCNJ5 and CYP11B2 (aldosterone synthase) showed markedly decreased KCNJ5 immunostaining in CYP11B2-positive cells compared with CYP11B2-negative cells in aldosterone-producing adenomas with a KCNJ5 mutation. Together, these findings support the concept that cell growth effects of KCNJ5 mutations are determined by the expression level of the mutated channel.


Assuntos
Glândulas Suprarrenais/metabolismo , Proliferação de Células/fisiologia , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/genética , Hiperaldosteronismo/genética , Glândulas Suprarrenais/patologia , Adulto , Idoso , Apoptose/fisiologia , Linhagem Celular , Feminino , Humanos , Hiperaldosteronismo/patologia , Masculino , Pessoa de Meia-Idade , Mutação
8.
J Steroid Biochem Mol Biol ; 193: 105422, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31265901

RESUMO

The adrenal cortex governs fundamental metabolic processes though synthesis of glucocorticoid, mineralocorticoids and androgens. Studies in rodents have demonstrated that the cortex undergoes a self-renewal process and that capsular/subcapsular stem/progenitor cell pools differentiate towards functional steroidogenic cells supporting the dynamic centripetal streaming of adrenocortical cells throughout life. We previously demonstrated that the Notch atypical ligand Delta-like homologue 1 (DLK1)/preadipocyte factor 1 (PREF1) is expressed in subcapsular Sf1 and Shh-positive, CYP11B1-negative and CYP11B2-partially positive cortical progenitor cells in rat adrenals, and that secreted DLK1 can modulate GLI1 expression in H295R cells. Here we show that the human adrenal cortex remodels with age to generate clusters of relatively undifferentiated cells expressing DLK1. These clusters (named DLK1-expressing cell clusters or DCCs) increased with age in size and were found to be different entities to aldosterone-producing cell clusters, another well-characterized and age-dependent cluster structure. DLK1 was markedly overexpressed in adrenocortical carcinomas but not in aldosterone-producing adenomas. Thus, this data identifies a novel cell population in the human adrenal cortex and might suggest a yet-to be identified role of DLK1 in the pathogenesis of adrenocortical carcinoma in humans.


Assuntos
Córtex Suprarrenal/citologia , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Membrana/metabolismo , Córtex Suprarrenal/metabolismo , Aldosterona/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Humanos
9.
Gen Comp Endocrinol ; 281: 173-182, 2019 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-31145891

RESUMO

Glucocorticoids (GCs) are secreted into the blood by the adrenal glands and are also locally-produced by organs such as the lymphoid organs (bone marrow, thymus, and spleen). Corticosterone is the primary circulating GC in many species, including mice, rats and birds. Within lymphoid organs, corticosterone can be locally produced from the inactive metabolite, 11-dehydrocorticosterone (DHC). However, very little is known about endogenous DHC levels, and no immunoassays are currently available to measure DHC. Here, we developed an easy-to-use and inexpensive immunoassay to measure DHC that is accurate, precise, sensitive, and specific. The DHC immunoassay was validated in multiple ways, including comparison with a mass spectrometry assay. After assay validations, we demonstrated the usefulness of this immunoassay by measuring DHC (and corticosterone) in mice, rats and song sparrows. Overall, corticosterone levels were higher than DHC levels across species. In Study 1, using mice, we measured steroids in whole blood and lymphoid organs at postnatal day (PND) 5, PND23, and PND90. Corticosterone and DHC showed distinct tissue-specific patterns across development. In Studies 2 and 3, we measured circulating corticosterone and DHC in adult rats and song sparrows, before and after restraint stress. In rats and song sparrows, restraint stress rapidly increased circulating levels of both steroids. This novel DHC immunoassay revealed major changes in DHC concentrations during development and in response to stress, which have important implications for understanding GC physiology, effects of stress on immune function, and regulation of local GC levels.


Assuntos
Envelhecimento/metabolismo , Corticosterona/análogos & derivados , Caracteres Sexuais , Aves Canoras/sangue , Estresse Fisiológico , Animais , Anticorpos/metabolismo , Corticosterona/sangue , Corticosterona/química , Reações Cruzadas , Feminino , Glucocorticoides/química , Glucocorticoides/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Ratos Long-Evans , Padrões de Referência
10.
Hypertension ; 73(6): 1283-1290, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31006333

RESUMO

Peripheral 18-oxocortisol (18oxoF) level could contribute to the detection of aldosterone-producing adenoma (APA) in patients with primary aldosteronism. However, peripheral 18oxoF varies among such patients, which is a big drawback concerning its clinical application. We studied 48 cases of APA, 35 harboring KCNJ5 mutation, to clarify the significance of clinical and pathological parameters about peripheral 18oxoF. Peripheral 18oxoF concentration ranged widely from 0.50 to 183.13 ng/dL and correlated positively with intratumoral areas stained positively for steroidogenic enzymes ( P<0.0001). The peripheral 18oxoF level also correlated significantly with that of circulating aldosterone ( P<0.0001) but not with that of cortisol, a precursor of 18oxoF. However, a significant correlation was detected between peripheral 18oxoF and intratumoral glucocorticoids ( P<0.05). In addition, peripheral 18oxoF correlated positively with the number of hybrid cells double positive for 11ß-hydroxylase and aldosterone synthase ( P<0.0001). Comparing between the cases with and those without KCNJ5 mutation, the KCNJ5-mutated group demonstrated a significantly higher concentration of peripheral 18oxoF (28.4±5.6 versus 3.0±0.9 ng/dL, P<0.0001) and a larger intratumoral environment including the hybrid cells ( P<0.001), possibly representing a deviation from normal aldosterone biosynthesis. After multivariate analysis, KCNJ5 mutation status turned out to be the most associated factor involved in 18oxoF synthesis in APA ( P<0.0001). Results of our present study first revealed that enhanced 18oxoF synthesis in APA could come from a functional deviation of aldosterone biosynthesis from the normal zona glomerulosa and the utility of peripheral 18oxoF measurement could be influenced by the prevalence of KCNJ5 mutation in an APA.


Assuntos
Neoplasias do Córtex Suprarrenal/genética , Adenoma Adrenocortical/genética , Aldosterona/metabolismo , DNA de Neoplasias/genética , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/genética , Hidrocortisona/análogos & derivados , Mutação/genética , Neoplasias do Córtex Suprarrenal/metabolismo , Adenoma Adrenocortical/metabolismo , Análise Mutacional de DNA , Feminino , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/metabolismo , Humanos , Hidrocortisona/biossíntese , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
11.
J Steroid Biochem Mol Biol ; 191: 105361, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30974191

RESUMO

Immunohistochemistry of human aldosterone synthase (CYP11B2) has revealed that most of aldosterone is autonomously produced in aldosterone-producing cell clusters (APCCs) beneath the capsule of adult adrenals rather than physiologically in the zona glomerulosa (ZG). APCCs have been occasionally found to harbor a somatic mutation of ion channel/pump genes, and number and size of APCCs increase with age until 50 years old. Herein, the objective of the study was to examine APCC development in 106 autopsied adrenals from 85 elderly individuals who died at ages from 50 to 103 years. We obtained the following results: (1) physiological CYP11B2 expression in ZG were attenuated in more elderly persons; (2) number and size of APCCs decreased with age; (3) detachment of APCC from the capsule appeared to occur occasionally over the wide range of the ages; and (4) incidental micro aldosterone-producing adenomas (APAs) and possible APCC-to-APA transitional lesions (pAATLs) were found primarily in samples from persons aged 50-60 years but not in samples from more elderly persons; pAATL was a putative designation based on our previous results indicating that it consisted of subcapsular APCC-like portion and inner APA-like portions. Thus, the formation of the CYP11B2-expressing lesions as well as thickening of the ZG in the adrenals were inversely correlated with age of death in the individuals aged over 50 years. Considering that autopsy samples were used in this study, inactive production of aldosterone regardless of autonomous or physiological manners may have survival advantages in individuals aged over 50 years.


Assuntos
Glândulas Suprarrenais/química , Citocromo P-450 CYP11B2/análise , Longevidade , Glândulas Suprarrenais/fisiologia , Glândulas Suprarrenais/ultraestrutura , Idoso , Idoso de 80 Anos ou mais , Envelhecimento , Aldosterona/metabolismo , Citocromo P-450 CYP11B2/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
12.
Sci Signal ; 12(577)2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30992401

RESUMO

Stress is increasingly associated with heart dysfunction and is linked to higher mortality rates in patients with cardiometabolic disease. Glucocorticoids are primary stress hormones that regulate homeostasis through two nuclear receptors, the glucocorticoid receptor (GR) and mineralocorticoid receptor (MR), both of which are present in cardiomyocytes. To examine the specific and coordinated roles that these receptors play in mediating the direct effects of stress on the heart, we generated mice with cardiomyocyte-specific deletion of GR (cardioGRKO), MR (cardioMRKO), or both GR and MR (cardioGRMRdKO). The cardioGRKO mice spontaneously developed cardiac hypertrophy and left ventricular systolic dysfunction and died prematurely from heart failure. In contrast, the cardioMRKO mice exhibited normal heart morphology and function. Despite the presence of myocardial stress, the cardioGRMRdKO mice were resistant to the cardiac remodeling, left ventricular dysfunction, and early death observed in the cardioGRKO mice. Gene expression analysis revealed the loss of gene changes associated with impaired Ca2+ handling, increased oxidative stress, and enhanced cell death and the presence of gene changes that limited the hypertrophic response and promoted cardiomyocyte survival in the double knockout hearts. Reexpression of MR in cardioGRMRdKO hearts reversed many of the cardioprotective gene changes and resulted in cardiac failure. These findings reveal a critical role for balanced cardiomyocyte GR and MR stress signaling in cardiovascular health. Therapies that shift stress signaling in the heart to favor more GR and less MR activity may provide an improved approach for treating heart disease.

13.
Hypertension ; 73(4): 885-892, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30739536

RESUMO

Somatic mutations have been identified in aldosterone-producing adenomas (APAs) in genes that include KCNJ5, ATP1A1, ATP2B3, and CACNA1D. Based on independent studies, there appears to be racial differences in the prevalence of somatic KCNJ5 mutations, particularly between East Asians and Europeans. Despite the high cardiovascular disease mortality of blacks, there have been no studies focusing on somatic mutations in APAs in this population. In the present study, we investigated genetic characteristics of APAs in blacks using a CYP11B2 (aldosterone synthase) immunohistochemistry-guided next-generation sequencing approach. The adrenal glands with adrenocortical adenomas from 79 black patients with primary aldosteronism were studied. Seventy-three tumors from 69 adrenal glands were confirmed to be APAs by CYP11B2 immunohistochemistry. Sixty-five of 73 APAs (89%) had somatic mutations in aldosterone-driver genes. Somatic CACNA1D mutations were the most prevalent genetic alteration (42%), followed by KCNJ5 (34%), ATP1A1 (8%), and ATP2B3 mutations (4%). CACNA1D mutations were more often observed in APAs from males than those from females (55% versus 29%, P=0.033), whereas KCNJ5 mutations were more prevalent in APAs from females compared with those from males (57% versus 13%, P<0.001). No somatic mutations in aldosterone-driver genes were identified in tumors without CYP11B2 expression. In conclusion, 89% of APAs in blacks harbor aldosterone-driving mutations, and unlike Europeans and East Asians, the most frequently mutated aldosterone-driver gene was CACNA1D. Determination of racial differences in the prevalence of aldosterone-driver gene mutations may facilitate the development of personalized medicines for patients with primary aldosteronism.


Assuntos
Neoplasias do Córtex Suprarrenal/genética , Adenoma Adrenocortical/genética , Afro-Americanos , Aldosterona/genética , Predisposição Genética para Doença , Mutação , Neoplasias do Córtex Suprarrenal/etnologia , Neoplasias do Córtex Suprarrenal/metabolismo , Glândulas Suprarrenais/patologia , Adenoma Adrenocortical/etnologia , Adenoma Adrenocortical/metabolismo , Aldosterona/metabolismo , Análise Mutacional de DNA , DNA de Neoplasias/genética , Humanos , Incidência , Estados Unidos/epidemiologia
14.
Genes Dev ; 33(3-4): 209-220, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30692207

RESUMO

Spatiotemporal control of Wnt signaling is essential for the development and homeostasis of many tissues. The transmembrane E3 ubiquitin ligases ZNRF3 (zinc and ring finger 3) and RNF43 (ring finger protein 43) antagonize Wnt signaling by promoting degradation of frizzled receptors. ZNRF3 and RNF43 are frequently inactivated in human cancer, but the molecular and therapeutic implications remain unclear. Here, we demonstrate that adrenocortical-specific loss of ZNRF3, but not RNF43, results in adrenal hyperplasia that depends on Porcupine-mediated Wnt ligand secretion. Furthermore, we discovered a Wnt/ß-catenin signaling gradient in the adrenal cortex that is disrupted upon loss of ZNRF3. Unlike ß-catenin gain-of-function models, which induce high Wnt/ß-catenin activation and expansion of the peripheral cortex, ZNRF3 loss triggers activation of moderate-level Wnt/ß-catenin signaling that drives proliferative expansion of only the histologically and functionally distinct inner cortex. Genetically reducing ß-catenin dosage significantly reverses the ZNRF3-deficient phenotype. Thus, homeostatic maintenance of the adrenal cortex is dependent on varying levels of Wnt/ß-catenin activation, which is regulated by ZNRF3.


Assuntos
Córtex Suprarrenal/metabolismo , Homeostase/genética , Ubiquitina-Proteína Ligases/metabolismo , Via de Sinalização Wnt/fisiologia , beta Catenina/metabolismo , Córtex Suprarrenal/citologia , Córtex Suprarrenal/crescimento & desenvolvimento , Doenças do Córtex Suprarrenal/fisiopatologia , Animais , Proliferação de Células/genética , Feminino , Técnicas de Inativação de Genes , Masculino , Camundongos , Modelos Animais , Ativação Transcricional/genética , Ubiquitina-Proteína Ligases/genética
16.
Hypertension ; 72(3): 632-640, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30354756

RESUMO

Aldosterone-producing adenomas (APAs) harbor marked intratumoral heterogeneity in terms of morphology, steroidogenesis, and genetics. However, an association of biological significance of morphologically identified tumor cell subtypes and genotypes is virtually unknown. KCNJ5 mutation is most frequently detected and generally considered a curable phenotype by adrenalectomy. Therefore, to explore the biological significance of KCNJ5 mutation in APA based on intracellular hormonal activities, 35 consecutively selected APAs (n=18; KCNJ5 mutated, n=17; wild type) were quantitatively examined in the whole tumor areas by newly developed digital image analysis incorporating their histological and ultrastructural features (14 cells from 2 KCNJ5-mutated APAs and 15 cells from 1 wild type) and CYP11B2 immunoreactivity. Results demonstrated that KCNJ5-mutated APAs had significantly lower nuclear/cytoplasm ratio and more abundant clear cells than wild type. CYP11B2 immunoreactivity was not significantly different between these genotypes, but a significant correlation was detected between the proportion of clear cells and CYP11B2 immunoreactivity in all of the APAs examined. CYP11B2 was predominantly immunolocalized in clear cells in KCNJ5-mutated APAs. Quantitative ultrastructural analysis revealed that KCNJ5-mutated APAs had significantly more abundant and smaller-sized mitochondria with well-developed cristae than wild type, whereas wild type had more abundant lipid droplets per unit area despite the small number of the cases examined. Our results did provide the novel insights into the morphological features of APA based on their biological significance. KCNJ5-mutated APAs were characterized by predominance of enlarged lipid-rich clear cells possibly resulting in increased neoplastic aldosterone biosynthesis.


Assuntos
Neoplasias do Córtex Suprarrenal/genética , Adenoma Adrenocortical/genética , Aldosterona/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/genética , Mutação , Neoplasias do Córtex Suprarrenal/metabolismo , Neoplasias do Córtex Suprarrenal/ultraestrutura , Adenoma Adrenocortical/metabolismo , Adenoma Adrenocortical/ultraestrutura , Adulto , Citocromo P-450 CYP11B2/metabolismo , Feminino , Humanos , Gotículas Lipídicas/ultraestrutura , Masculino , Microscopia Eletrônica de Transmissão , Pessoa de Meia-Idade , Mitocôndrias/ultraestrutura
17.
Hypertension ; 72(3): 650-657, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30012870

RESUMO

Unilateral primary aldosteronism (PA) is the most common surgically curable form of hypertension that must be accurately differentiated from bilateral PA for therapeutic management (surgical versus medical). Adrenalectomy results in biochemical cure (complete biochemical success) in almost all patients diagnosed with unilateral PA; the remaining patients with partial or absent biochemical success comprise those with persisting aldosteronism who were misdiagnosed as unilateral PA preoperatively. To identify determinants of postsurgical biochemical outcomes, we compared the adrenal histopathology and the peripheral venous steroid profiles of patients with partial and absent or complete biochemical success after adrenalectomy for unilateral PA. A large multicenter cohort of adrenals from patients with absent and partial biochemical success (n=43) displayed a higher prevalence of hyperplasia (49% versus 21%; P=0.004) and a lower prevalence of solitary functional adenoma (44% versus 79%; P<0.001) compared with adrenals from age- and sex-matched patients with PA with complete biochemical success (n=52). We measured the peripheral plasma steroid concentrations in a subgroup of these patients (n=43) and in a group of patients with bilateral PA (n=27). Steroid profiling was associated with histopathologic phenotypes (solitary functional adenoma, hyperplasia, and aldosterone-producing cell clusters) and classified patients according to biochemical outcome or diagnosis of bilateral PA. If validated, peripheral venous steroid profiling may be a useful tool to guide the decision to perform surgery based on expectations of biochemical outcome after the procedure.


Assuntos
Glândulas Suprarrenais/cirurgia , Adrenalectomia/métodos , Aldosterona/sangue , Hiperaldosteronismo/cirurgia , Glândulas Suprarrenais/metabolismo , Glândulas Suprarrenais/patologia , Adulto , Citocromo P-450 CYP11B2/metabolismo , Feminino , Humanos , Hiperaldosteronismo/sangue , Hiperaldosteronismo/metabolismo , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , /estatística & dados numéricos
18.
Endocr Rev ; 39(6): 1029-1056, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30007283

RESUMO

The identification of several germline and somatic ion channel mutations in aldosterone-producing adenomas (APAs) and detection of cell clusters that can be responsible for excess aldosterone production, as well as the isolation of autoantibodies activating the angiotensin II type 1 receptor, have rapidly advanced the understanding of the biology of primary aldosteronism (PA), particularly that of APA. Hence, the main purpose of this review is to discuss how discoveries of the last decade could affect histopathology analysis and clinical practice. The structural remodeling through development and aging of the human adrenal cortex, particularly of the zona glomerulosa, and the complex regulation of aldosterone, with emphasis on the concepts of zonation and channelopathies, will be addressed. Finally, the diagnostic workup for PA and its subtyping to optimize treatment are reviewed.


Assuntos
Neoplasias do Córtex Suprarrenal , Adenoma Adrenocortical , Envelhecimento , Aldosterona/metabolismo , Hiperaldosteronismo , Zona Glomerulosa , Neoplasias do Córtex Suprarrenal/diagnóstico , Neoplasias do Córtex Suprarrenal/metabolismo , Neoplasias do Córtex Suprarrenal/patologia , Adenoma Adrenocortical/diagnóstico , Adenoma Adrenocortical/metabolismo , Adenoma Adrenocortical/patologia , Envelhecimento/metabolismo , Envelhecimento/patologia , Humanos , Hiperaldosteronismo/diagnóstico , Hiperaldosteronismo/metabolismo , Hiperaldosteronismo/patologia , Zona Glomerulosa/metabolismo , Zona Glomerulosa/patologia
19.
J Neuromuscul Dis ; 5(3): 295-306, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30010143

RESUMO

BACKGROUND: Mineralocorticoid receptor antagonists added to angiotensin converting enzyme inhibitors have shown preclinical efficacy for both skeletal and cardiac muscle outcomes in young sedentary dystrophin-deficient mdx mice also haploinsufficient for utrophin, a Duchenne muscular dystrophy (DMD) model. The mdx genotypic DMD model has mild pathology, making non-curative therapeutic effects difficult to distinguish at baseline. Since the cardiac benefit of mineralocorticoid receptor antagonists has been translated to DMD patients, it is important to optimize potential advantages for skeletal muscle by further defining efficacy parameters. OBJECTIVE: We aimed to test whether therapeutic effects of mineralocorticoid receptor antagonists added to angiotensin converting enzyme inhibitors are detectable using three different reported methods of exacerbating the mdx phenotype. METHODS: We tested treatment with lisinopril and the mineralocorticoid receptor antagonist spironolactone in: 10 week-old exercised, 1 year-old sedentary, and 5 month-old isoproterenol treated mdx mice and performed comprehensive functional and histological measurements. RESULTS: None of the protocols to exacerbate mdx phenotypes resulted in dramatically enhanced pathology and no significant benefit was observed with treatment. CONCLUSIONS: Since endogenous mineralocorticoid aldosterone production from immune cells in dystrophic muscle may explain antagonist efficacy, it is likely that these drugs work optimally during the narrow window of peak inflammation in mdx mice. Exercised and aged mdx mice do not display prolific damage and inflammation, likely explaining the absence of continued efficacy of these drugs. Since inflammation is more prevalent in DMD patients, the therapeutic window for mineralocorticoid receptor antagonists in patients may be longer.


Assuntos
Envelhecimento , Antagonistas de Receptores de Mineralocorticoides/uso terapêutico , Distrofia Muscular de Duchenne/tratamento farmacológico , Condicionamento Físico Animal , Agonistas Adrenérgicos beta/farmacologia , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Animais , Modelos Animais de Doenças , Coração/efeitos dos fármacos , Inflamação/etiologia , Inflamação/patologia , Isoproterenol/farmacologia , Camundongos , Camundongos Endogâmicos mdx/genética , Força Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Distrofia Muscular de Duchenne/diagnóstico por imagem , Distrofia Muscular de Duchenne/patologia , Comportamento Sedentário , Espironolactona/uso terapêutico
20.
J Clin Endocrinol Metab ; 103(3): 965-971, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29294065

RESUMO

Context: Aldosterone production is stimulated by activation of calcium signaling in aldosterone-producing adenomas (APAs), and epigenetic factors such as DNA methylation may be associated with the expression of genes involved in aldosterone regulation. Objective: Our aim was to investigate the DNA methylation of genes related to calcium signaling cascades in APAs and the association of mutations in genes linked to APAs with DNA methylation levels. Methods: Nonfunctioning adrenocortical adenoma (n = 12) and APA (n = 35) samples were analyzed. The KCNJ5 T158A mutation was introduced into human adrenocortical cell lines (HAC15 cells) using lentiviral delivery. DNA methylation array analysis was conducted using adrenal tumor samples and HAC15 cells. Results: The Purkinje cell protein 4 (PCP4) gene was one of the most hypomethylated in APAs. DNA methylation levels in two sites of PCP4 showed a significant inverse correlation with messenger RNA expression in adrenal tumors. Bioinformatics and multiple regression analysis revealed that CCAAT/enhancer binding protein alpha (CEBPA) may bind to the methylation site of the PCP4 promoter. According to chromatin immunoprecipitation assay, CEBPA was bound to the PCP4 hypomethylated region by chromatin immunoprecipitation assay. There were no significant differences in PCP4 methylation levels among APA genotypes. Moreover, KCNJ5 T158A did not influence PCP4 methylation levels in HAC15 cells. Conclusions: We showed that the PCP4 promoter was one of the most hypomethylated in APAs and that PCP4 transcription may be associated with demethylation as well as with CEBPA in APAs. KCNJ5 mutations known to result in aldosterone overproduction were not related to PCP4 methylation in either clinical or in vitro studies.


Assuntos
Neoplasias do Córtex Suprarrenal/genética , Adenoma Adrenocortical/genética , Aldosterona/biossíntese , Metilação de DNA/fisiologia , Proteínas do Tecido Nervoso/biossíntese , Neoplasias do Córtex Suprarrenal/metabolismo , Adenoma Adrenocortical/metabolismo , Adulto , Sinalização do Cálcio/genética , Sinalização do Cálcio/fisiologia , Calmodulina/metabolismo , DNA de Neoplasias/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Proteínas do Tecido Nervoso/genética , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Neoplásico/genética , Células Tumorais Cultivadas
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