Sample records for aldosterone synthase expression

  1. Molecular identity and gene expression of aldosterone synthase cytochrome P450

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Okamoto, Mitsuhiro; Nonaka, Yasuki; Takemori, Hiroshi

    11{beta}-Hydroxylase (CYP11B1) of bovine adrenal cortex produced corticosterone as well as aldosterone from 11-deoxycorticosterone in the presence of the mitochondrial P450 electron transport system. CYP11B1s of pig, sheep, and bullfrog, when expressed in COS-7 cells, also performed corticosterone and aldosterone production. Since these CYP11B1s are present in the zonae fasciculata and reticularis as well as in the zona glomerulosa, the zonal differentiation of steroid production may occur by the action of still-unidentified factor(s) on the enzyme-catalyzed successive oxygenations at C11- and C18-positions of steroid. In contrast, two cDNAs, one encoding 11{beta}-hydroxylase and the other encoding aldosterone synthase (CYP11B2), were isolatedmore » from rat, mouse, hamster, guinea pig, and human adrenals. The expression of CYP11B1 gene was regulated by cyclic AMP (cAMP)-dependent signaling, whereas that of CYP11B2 gene by calcium ion-signaling as well as cAMP-signaling. Salt-inducible protein kinase, a cAMP-induced novel protein kinase, was one of the regulators of CYP11B2 gene expression.« less

  2. Investigation of aldosterone-synthase inhibition in rats.

    PubMed

    Ménard, Joël; Gonzalez, Marie-Françoise; Guyene, Thanh-Tam; Bissery, Alvine

    2006-06-01

    In-vivo investigation of aldosterone-synthase inhibitors requires experimental models to characterize the biological effects of these compounds. Seven successive experiments were performed in groups of 2-month-old male spontaneously hypertensive rats. Urinary free aldosterone was the main end-point measured during two contrasted diets: low sodium-high potassium (LS), inducing high urinary aldosterone (839 pmol/24 h, 95% confidence interval 654-1077), and high sodium-normal potassium (HS), inducing low urinary aldosterone (38.1 pmol/24 h; 95% confidence interval, 32.4-44.9). FAD 286 A (10 and 30 mg/kg) decreased urinary free aldosterone by 53 and 87% on the LS diet, and 50 and 75% on the HS. Plasma renin concentration increased three-fold after a 4-week treatment of 30 mg/kg FAD 286 A on the LS diet and did not change on the HS. The combination of FAD 286 A (30 mg/kg) and spironolactone (30 mg/kg) on the LS diet induced a biological picture of severe hypoaldosteronism and was not tolerated, whereas the HS diet prevented these abnormalities. The combination of FAD 286 A (30 mg/kg) and furosemide (30 mg/kg) on the HS diet corrected the diuretic-induced hypokalemia (4.1 +/- 0.2 versus 3.7 +/- 2.2 mEq/l, P < 0.033). This experimental model will be useful to screen future aldosterone-synthase inhibitors and study their biological effects in various experimental conditions.

  3. The Aldosterone Synthase Inhibitor FAD286 is Suitable for Lowering Aldosterone Levels in ZDF Rats but not in db/db Mice.

    PubMed

    Hofmann, Anja; Brunssen, Coy; Peitzsch, Mirko; Balyura, Mariya; Mittag, Jennifer; Frenzel, Annika; Jannasch, Anett; Brown, Nicholas F; Weldon, Steven M; Gueneva-Boucheva, Kristina K; Eisenhofer, Graeme; Bornstein, Stefan R; Morawietz, Henning

    2017-06-01

    Inhibition of aldosterone synthase is an alternative treatment option to mineralocorticoid receptor antagonism to prevent harmful aldosterone actions. FAD286 is one of the best characterized aldosterone synthase inhibitors to date. FAD286 improves glucose tolerance and increases glucose-stimulated insulin secretion in obese and diabetic ZDF rats. However, there is limited knowledge about the dose-dependent effects of FAD286 on plasma aldosterone, corticosterone, and 11-deoxycorticosterone in ZDF rats and in db / db mice, a second important rodent model of obesity and type 2 diabetes. In addition, effects of FAD286 on plasma steroids in mice and rats are controversial. Therefore, obese Zucker diabetic fatty (ZDF) rats and db / db mice were treated with FAD286 for up to 15 weeks and plasma steroids were evaluated using highly sensitive liquid chromatography-tandem mass spectrometry. In ZDF rats, FAD286 (10 mg/kg/d) treatment resulted in nearly complete disappearance of plasma aldosterone while corticosterone levels remained unaffected and those of 11-deoxycorticosterone were increased ~4-fold compared to vehicle control. A lower dose of FAD286 (3 mg/kg / d) showed no effect on plasma aldosterone or corticosterone, but 11-deoxycorticosterone was again increased ~4-fold compared to control. In contrast to ZDF rats, a high dose of FAD286 (40 mg/kg/d) did not affect plasma aldosterone levels in db / db mice although 11-deoxycorticosterone increased ~2.5-fold. A low dose of FAD286 (10 mg/kg/d) increased plasma aldosterone without affecting corticosterone or 11-deoxycorticosterone. In conclusion, the aldosterone synthase inhibitor, FAD286, lowers plasma aldosterone in obese ZDF rats, but not in obese db / db mice. © Georg Thieme Verlag KG Stuttgart · New York.

  4. GPER-1 and estrogen receptor-β ligands modulate aldosterone synthesis.

    PubMed

    Caroccia, Brasilina; Seccia, Teresa M; Campos, Abril Gonzalez; Gioco, Francesca; Kuppusamy, Maniselvan; Ceolotto, Giulio; Guerzoni, Eugenia; Simonato, Francesca; Mareso, Sara; Lenzini, Livia; Fassina, Ambrogio; Rossi, Gian Paolo

    2014-11-01

    Fertile women have lower blood pressure and cardiovascular risk than age-matched men, which suggests that estrogens exert cardiovascular protective effects. However, whether 17 β-estradiol (E2) blunts aldosterone secretion, and thereby affects the gender dimorphism of blood pressure, is unknown. We therefore sought for the estrogen receptor (ER) subtypes in human adrenocortical tissues ex vivo by performing gene and protein expression studies. We also investigated the effect of E2 on aldosterone synthesis and the involved receptors through in vitro functional experiments in the adrenocortical cells HAC15. We found that in the human adrenal cortex and aldosterone-producing adenoma cells, the most expressed ERs were the ERβ and the G protein-coupled receptor-1 (GPER-1), respectively. After selective ERβ blockade, E2 (10 nmol/L) markedly increased both the expression of aldosterone synthase and the production of aldosterone (+5- to 7-fold vs baseline, P < .001). Under the same condition, the GPER-1 receptor agonist 1-[4-(6-bromo-benzo (1, 3)dioxol-5-yl)-3a,4,5,9b-tetrahydro-3H-cyclopenta[c] quinolin-8-yl]-ethanone (G-1) (10 nmol/L) mimicked this effect, which was abrogated by cotreatment with either the GPER-1 receptor antagonist (3aS*,4R*,9bR*)-4-(6-Bro-mo-1,3-benzodioxol-5-yl)-3a,4,5,9b-3H-cyclopenta[c]quinoline (G-15), or a selective protein kinase A inhibitor 8-Bromo-2-monobutyryladenosine-3,5-cyclic mono-phosphorothioate, Rp-isomer. Silencing of the ERβ significantly raised aldosterone synthase expression and aldosterone production. Conversely, silencing of the GPER-1 lowered aldosterone synthase gene and protein expression. Moreover, it blunted the stimulatory effect of E2 on aldosterone synthase that was seen during ERβ blockade. These results support the conclusion that in humans, E2 inhibits aldosterone synthesis by acting via ERβ. Pharmacologic disinhibition of ERβ unmasks a potent secretagogue effect of E2 that involves GPER-1 and protein kinase A

  5. FAD286, an aldosterone synthase inhibitor, reduced atherosclerosis and inflammation in apolipoprotein E-deficient mice.

    PubMed

    Gamliel-Lazarovich, Aviva; Gantman, Anna; Coleman, Raymond; Jeng, Arco Y; Kaplan, Marielle; Keidar, Shlomo

    2010-09-01

    Aldosterone is known to be involved in atherosclerosis and cardiovascular disease and blockade of its receptor was shown to improve cardiovascular function. It was, therefore, hypothesized that inhibition of aldosterone synthesis would also reduce atherosclerosis development. To test this hypothesis, we examined the effect of FAD286 (FAD), an aldosterone synthase inhibitor, on the development of atherosclerosis in spontaneous atherosclerotic apolipoprotein E-deficient mice. Mice were divided into three treatment groups: normal diet, low-salt diet (LSD) and LSD treated with FAD at 30 mg/kg per day (LSD + FAD) for 10 weeks. Histomorphometry of the aortas obtained from these mice showed that atherosclerotic lesion area increased by three-fold under LSD compared with normal diet and FAD significantly reduced lesion area to values similar to normal diet. Changes in atherosclerosis were paralleled by changes in the expression of the inflammation markers (C-reactive protein, monocyte chemotactic protein-1, interleukin-6, nuclear factor kappa B and intercellular adhesion molecule-1) in peritoneal macrophages obtained from these mice. Surprisingly, whereas LSD increased serum or urine aldosterone levels, FAD did not alter these levels when evaluated at the end of the study. In J774A.1 macrophage-like cell line stimulated with lipopolysaccharide, FAD was shown to have a direct dose-dependent anti-inflammatory effect. In apolipoprotein E-deficient mice, FAD reduces atherosclerosis and inflammation. However, these actions appeared to be dissociated from its effect on inhibition of aldosterone synthesis.

  6. Acute and Chronic Regulation of Aldosterone Production

    PubMed Central

    Hattangady, Namita; Olala, Lawrence; Bollag, Wendy B.; Rainey, William E.

    2011-01-01

    Aldosterone is the major mineralocorticoid synthesized by the adrenal. Secretion of aldosterone is regulated tightly by the adrenocortical glomerulosa cells due to the selective expression of CYP11B2 in the outermost zone, the zona glomerulosa. Aldosterone is largely responsible for regulation of systemic blood pressure through the absorption of electrolytes and water under the regulation of certain specific agonists. Angiotensin II (Ang II), potassium (K+) and adrenocorticotropin (ACTH) are the main physiological agonists which regulate aldosterone secretion. The mechanisms involved in this process may be regulated minutes after a stimulus (acutely) through increased expression and phosphorylation of the steroidogenic acute regulatory (StAR) protein, over hours to days (chronically) by increased expression of the enzymes involved in the synthesis of aldosterone, particularly aldosterone synthase (CYP11B2). Imbalance in any of these processes may lead to several aldosterone excess disorders. In this review we attempt to summarize the key molecular events involved in and specifically attributed to the acute and chronic phases of aldosterone secretion. PMID:21839803

  7. Collecting Duct Nitric Oxide Synthase 1ß Activation Maintains Sodium Homeostasis During High Sodium Intake Through Suppression of Aldosterone and Renal Angiotensin II Pathways.

    PubMed

    Hyndman, Kelly A; Mironova, Elena V; Giani, Jorge F; Dugas, Courtney; Collins, Jessika; McDonough, Alicia A; Stockand, James D; Pollock, Jennifer S

    2017-10-24

    During high sodium intake, the renin-angiotensin-aldosterone system is downregulated and nitric oxide signaling is upregulated in order to remain in sodium balance. Recently, we showed that collecting duct nitric oxide synthase 1β is critical for fluid-electrolyte balance and subsequently blood pressure regulation during high sodium feeding. The current study tested the hypothesis that high sodium activation of the collecting duct nitric oxide synthase 1β pathway is critical for maintaining sodium homeostasis and for the downregulation of the renin-angiotensin-aldosterone system-epithelial sodium channel axis. Male control and collecting duct nitric oxide synthase 1β knockout (CDNOS1KO) mice were placed on low, normal, and high sodium diets for 1 week. In response to the high sodium diet, plasma sodium was significantly increased in control mice and to a significantly greater level in CDNOS1KO mice. CDNOS1KO mice did not suppress plasma aldosterone in response to the high sodium diet, which may be partially explained by increased adrenal AT1R expression. Plasma renin concentration was appropriately suppressed in both genotypes. Furthermore, CDNOS1KO mice had significantly higher intrarenal angiotensin II with high sodium diet, although intrarenal angiotensinogen levels and angiotensin-converting enzyme activity were similar between knockout mice and controls. In agreement with inappropriate renin-angiotensin-aldosterone system activation in the CDNOS1KO mice on a high sodium diet, epithelial sodium channel activity and sodium transporter abundance were significantly higher compared with controls. These data demonstrate that high sodium activation of collecting duct nitric oxide synthase 1β signaling induces suppression of systemic and intrarenal renin-angiotensin-aldosterone system, thereby modulating epithelial sodium channel and other sodium transporter abundance and activity to maintain sodium homeostasis. © 2017 The Authors. Published on behalf of the

  8. Effect of KCNJ5 Mutations on Gene Expression in Aldosterone-Producing Adenomas and Adrenocortical Cells

    PubMed Central

    Monticone, Silvia; Hattangady, Namita G.; Nishimoto, Koshiro; Mantero, Franco; Rubin, Beatrice; Cicala, Maria Verena; Pezzani, Raffaele; Auchus, Richard J.; Ghayee, Hans K.; Shibata, Hirotaka; Kurihara, Isao; Williams, Tracy A.; Giri, Judith G.; Bollag, Roni J.; Edwards, Michael A.; Isales, Carlos M.

    2012-01-01

    Context: Primary aldosteronism is a heterogeneous disease that includes both sporadic and familial forms. A point mutation in the KCNJ5 gene is responsible for familial hyperaldosteronism type III. Somatic mutations in KCNJ5 also occur in sporadic aldosterone producing adenomas (APA). Objective: The objective of the study was to define the effect of the KCNJ5 mutations on gene expression and aldosterone production using APA tissue and human adrenocortical cells. Methods: A microarray analysis was used to compare the transcriptome profiles of female-derived APA samples with and without KCNJ5 mutations and HAC15 adrenal cells overexpressing either mutated or wild-type KCNJ5. Real-time PCR validated a set of differentially expressed genes. Immunohistochemical staining localized the KCNJ5 expression in normal adrenals and APA. Results: We report a 38% (18 of 47) prevalence of KCNJ5 mutations in APA. KCNJ5 immunostaining was highest in the zona glomerulosa of NA and heterogeneous in APA tissue, and KCNJ5 mRNA was 4-fold higher in APA compared with normal adrenals (P < 0.05). APA with and without KCNJ5 mutations displayed slightly different gene expression patterns, notably the aldosterone synthase gene (CYP11B2) was more highly expressed in APA with KCNJ5 mutations. Overexpression of KCNJ5 mutations in HAC15 increased aldosterone production and altered expression of 36 genes by greater than 2.5-fold (P < 0.05). Real-time PCR confirmed increases in CYP11B2 and its transcriptional regulator, NR4A2. Conclusions: KCNJ5 mutations are prevalent in APA, and our data suggest that these mutations increase expression of CYP11B2 and NR4A2, thus increasing aldosterone production. PMID:22628608

  9. Calneuron 1 Increased Ca2+ in the Endoplasmic Reticulum and Aldosterone Production in Aldosterone-Producing Adenoma.

    PubMed

    Kobuke, Kazuhiro; Oki, Kenji; Gomez-Sanchez, Celso E; Gomez-Sanchez, Elise P; Ohno, Haruya; Itcho, Kiyotaka; Yoshii, Yoko; Yoneda, Masayasu; Hattori, Noboru

    2018-01-01

    Aldosterone production is initiated by angiotensin II stimulation and activation of intracellular Ca 2+ signaling. In aldosterone-producing adenoma (APA) cells, the activation of intracellular Ca 2+ signaling is independent of the renin-angiotensin-aldosterone systems. The purpose of our study was to clarify molecular mechanisms of aldosterone production related to Ca 2+ signaling. Transcriptome analysis revealed that the CALN1 gene encoding calneuron 1 had the strongest correlation with CYP11B2 (aldosterone synthase) among genes encoding Ca 2+ -binding proteins in APA. CALN1 modulation and synthetic or fluorescent compounds were used for functional studies in human adrenocortical carcinoma (HAC15) cells. CALN1 expression was 4.4-fold higher in APAs than nonfunctioning adrenocortical adenomas. CALN1 expression colocalized with CYP11B2 expression as investigated using immunohistochemistry in APA and zona glomerulosa of male rats fed by a low-salt diet. CALN1 expression was detected in the endoplasmic reticulum (ER) by using GFP-fused CALN1, CellLight ER-RFP, and the corresponding antibodies. CALN1 -overexpressing HAC15 cells showed increased Ca 2+ in the ER and cytosol fluorescence-based studies. Aldosterone production was potentiated in HAC15 cells by CALN1 expression, and dose-responsive inhibition with TMB-8 showed that CALN1-mediated Ca 2+ storage in ER involved sarcoendoplasmic reticulum calcium transport ATPase. The silencing of CALN1 decreased Ca 2+ in ER, and abrogated angiotensin II- or KCNJ5 T158A-mediated aldosterone production in HAC15 cells. Increased CALN1 expression in APA was associated with elevated Ca 2+ storage in ER and aldosterone overproduction. Suppression of CALN1 expression prevented angiotensin II- or KCNJ5 T158A-mediated aldosterone production in HAC15 cells, suggesting that CALN1 is a potential therapeutic target for excess aldosterone production. © 2017 American Heart Association, Inc.

  10. Aldosterone synthase inhibition improves cardiovascular function and structure in rats with heart failure: a comparison with spironolactone.

    PubMed

    Mulder, Paul; Mellin, Virginie; Favre, Julie; Vercauteren, Magali; Remy-Jouet, Isabelle; Monteil, Christelle; Richard, Vincent; Renet, Sylvanie; Henry, Jean Paul; Jeng, Arco Y; Webb, Randy L; Thuillez, Christian

    2008-09-01

    Inhibition of aldosterone synthase, the key enzyme in aldosterone formation, could be an alternative strategy for mineralocorticoid-receptor antagonists in congestive heart failure (CHF), but its effect in CHF is unknown. We compared, in rats with CHF, the effects of a 7 day and a 12 week treatment with the aldosterone synthase inhibitor FAD286 (4 mg kg(-1) day(-1)) with those induced by spironolactone (80 mg kg(-1) day(-1)). FAD286/spironolactone increased cardiac output without modifying arterial pressure. Long-term FAD286 and spironolactone reduced left ventricular (LV) end-diastolic pressure, LV relaxation constant, and LV dilatation, and these effects were more marked with FAD286, whereas both drugs reduced LV hypertrophy and collagen accumulation to the same extent. Long-term FAD286/spironolactone prevented CHF-related enhancement in LV ACE and reduction in LV ACE-2, but only FAD286 prevented the reduction in LV AT(2) receptors. FAD286, but not long-term spironolactone, reduced the CHF-related enhancements in LV reactive oxygen species, reduced-oxidized glutathione ratio, and aortic nicotinamide adenine dinucleotide phosphate oxidase activity. FAD286 normalized the CHF-induced impairment of endothelium-dependent vasodilatation. In experimental CHF, FAD286 and spironolactone improve LV haemodynamics, remodelling, and function, but only FAD286 persistently normalizes LV 'redox status'. These results suggest that aldosterone synthase inhibition is a potential therapeutic strategy for the treatment of CHF.

  11. GSTA1 Expression Is Correlated With Aldosterone Level in KCNJ5-Mutated Adrenal Aldosterone-Producing Adenoma.

    PubMed

    Li, Xintao; Wang, Baojun; Tang, Lu; Zhang, Yu; Chen, Luyao; Gu, Liangyou; Zhang, Fan; Ouyang, Jinzhi; Zhang, Xu

    2018-03-01

    KCNJ5 mutation is a major cause of aldosterone-producing adenomas (APAs). The development of APA apart from KCNJ5 mutation is less investigated. To investigate other mechanisms affecting aldosterone secretion apart from KCNJ5. Six pairs of KCNJ5-mutated, high and low aldosterone-secreting APAs, five non-KCNJ5-mutated APAs, and four normal adrenal glands were assayed by Affymetrix GeneChip Human Transcriptome Array 2.0. A total of 113 APA samples were investigated to explore the expression of glutathione-S-transferase A1 (GSTA1). H295R cells were used to verify the function of GSTA1. GSTA1 was the top gene downregulated in high-aldosterone KCNJ5-mutated APAs. GSTA1 was also downregulated in KCNJ5-mutated APAs compared with wild-type KCNJ5 APAs. Accordingly, mutant KCNJ5 decreased GSTA1 messenger RNA and protein expression levels. GSTA1 overexpression suppressed aldosterone secretion whether in wild-type or mutant KCNJ5 H295R cells. Adding ethacrynic acid or silencing of GSTA1 increased aldosterone secretion by increasing reactive oxygen species (ROS), superoxide, H2O2 levels, and Ca2+ influx. The expression of the transcription factors NR4A1, NR4A2, and CAMK1 and intracellular Ca2+ were significantly upregulated by GSTA1 inhibition. The reduced form of NAD phosphate oxidase inhibitor or H2O2 scavenger or blocking calmodulin or calcium channels could significantly reduce aldosterone secretion in GSTA1-inhibited cells. (1) GSTA1 expression is reversely correlated with aldosterone level in KCNJ5-mutated APAs, (2) GSTA1 regulates aldosterone secretion by ROS and Ca2+ signaling, and (3) KCNJ5 mutation downregulates GSTA1 expression, and overexpression of GSTA1 reverses increased aldosterone in KCNJ5-mutated adrenal cells.

  12. Quantitative assessment of CYP11B1 and CYP11B2 expression in aldosterone-producing adenomas.

    PubMed

    Fallo, F; Pezzi, V; Barzon, L; Mulatero, P; Veglio, F; Sonino, N; Mathis, J M

    2002-12-01

    The presence and pathophysiological role of CYP11B1 (11beta-hydroxylase) gene in the zona glomerulosa of human adrenal cortex is still controversial. In order to specifically quantify CYP11B1, CYP11B2 (aldosterone synthase) and CYP17(17alpha-hydroxylase) mRNA levels, we developed a real-time RT-PCR assay and examined the expression in a series of adrenal tIssues, including six normal adrenals from patients adrenalectomized for renal cancer and twelve aldosterone-producing adenomas (APA) from patients with primary aldosteronism. CYP11B1 mRNA levels were clearly detected in normal adrenals, which comprised both zona glomerulosa and fasciculata/reticularis cells, but were also measured at a lower range (P<0.05) in APA. The levels of CYP11B2 mRNA were lower (P<0.005) in normal adrenals than in APA. CYP17 mRNAlevels were similar in normal adrenals and in APA. In patients with APA, CYP11B2 and CYP11B1 mRNA levels were not correlated either with basal aldosterone or with the change from basal aldosterone in response to posture or to dexamethasone. No correlation between CYP11B1 mRNA or CYP11B2 mRNA and the percentage of zona fasciculata-like cells was observed in APA. Real-time RT-PCR can be reliably used to quantify CYP11B1 and CYP11B2 mRNA levels in adrenal tIssues. Expression of CYP11B1 in hyperfunctioning zona glomerulosa suggests an additional formation of corticosterone via 11beta-hydroxylase, providing further substrate for aldosterone biosynthesis. CYP11B1 and CYP11B2 mRNA levels in APA are not related to the in vivo secretory activity of glomerulosa cells, where post-transcriptional factors might ultimately regulate aldosterone production.

  13. Suppressive effects of RXR agonist PA024 on adrenal CYP11B2 expression, aldosterone secretion and blood pressure.

    PubMed

    Suzuki, Dai; Saito-Hakoda, Akiko; Ito, Ryo; Shimizu, Kyoko; Parvin, Rehana; Shimada, Hiroki; Noro, Erika; Suzuki, Susumu; Fujiwara, Ikuma; Kagechika, Hiroyuki; Rainey, William E; Kure, Shigeo; Ito, Sadayoshi; Yokoyama, Atsushi; Sugawara, Akira

    2017-01-01

    The effects of retinoids on adrenal aldosterone synthase gene (CYP11B2) expression and aldosterone secretion are still unknown. We therefore examined the effects of nuclear retinoid X receptor (RXR) pan-agonist PA024 on CYP11B2 expression, aldosterone secretion and blood pressure, to elucidate its potential as a novel anti-hypertensive drug. We demonstrated that PA024 significantly suppressed angiotensin II (Ang II)-induced CYP11B2 mRNA expression, promoter activity and aldosterone secretion in human adrenocortical H295R cells. Human CYP11B2 promoter functional analyses using its deletion and point mutants indicated that the suppression of CYP11B2 promoter activity by PA024 was in the region from -1521 (full length) to -106 including the NBRE-1 and the Ad5 elements, and the Ad5 element may be mainly involved in the PA024-mediated suppression. PA024 also significantly suppressed the Ang II-induced mRNA expression of transcription factors NURR1 and NGFIB that bind to and activate the Ad5 element. NURR1 overexpression demonstrated that the decrease of NURR1 expression may contribute to the PA024-mediated suppression of CYP11B2 transcription. PA024 also suppressed the Ang II-induced mRNA expression of StAR, HSD3β2 and CYP21A2, a steroidogenic enzyme group involved in aldosterone biosynthesis. Additionally, the PA024-mediated CYP11B2 transcription suppression was shown to be exerted via RXRα. Moreover, the combination of PPARγ agonist pioglitazone and PA024 caused synergistic suppressive effects on CYP11B2 mRNA expression. Finally, PA024 treatment significantly lowered both the systolic and diastolic blood pressure in Tsukuba hypertensive mice (hRN8-12 x hAG2-5). Thus, RXR pan-agonist PA024 may be a candidate anti-hypertensive drugs that acts via the suppression of aldosterone synthesis and secretion.

  14. Angiotensin II-aldosterone interaction in human coronary microarteries involves GPR30, EGFR, and endothelial NO synthase.

    PubMed

    Batenburg, Wendy W; Jansen, Pieter M; van den Bogaerdt, Antoon J; J Danser, Alexander H

    2012-04-01

    The aim of this study was to investigate the aldosterone-angiotensin (Ang) II interaction in human coronary microarteries (HCMAs). HCMAs, obtained from 75 heart-beating organ donors, were mounted in myographs and exposed to Ang II, either directly or following a 30-min pre-incubation with aldosterone, 17β-oestradiol, hydrocortisone, the p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580, the extracellular regulated kinase 1/2 (ERK1/2) inhibitor PD98059, the GPR30 antagonist G15, or the epidermal growth factor receptor (EGFR) antagonist AG1478. Ang II constricted HCMAs in a concentration-dependent manner. All steroids, at nanomolar levels, potentiated Ang II and G15 prevented this effect. The potentiation disappeared or was reversed into Ang II antagonism at micromolar steroid levels. NO synthase (NOS) inhibition prevented the latter antagonism in the case of 17β-oestradiol, whereas both aldosterone and 17β-oestradiol at micro- (but not nano-) molar levels induced endothelial NOS phosphorylation in human umbilical vein endothelial cells. AG1478, but not SB203580 or PD98059, abolished the Ang II-induced contraction in the presence of aldosterone or 17β-oestradiol, and none of these drugs affected Ang II alone. Steroids including aldosterone affect Ang II-induced vasoconstriction in a biphasic manner. Potentiation occurs at nanomolar steroid levels and depends on GPR30 and EGFR transactivation. At micromolar steroid levels, this potentiation either disappears (aldosterone and hydrocortisone) or is reversed into an inhibition (17β-oestradiol), and this is due to the endothelial NOS activation that occurs at such concentrations.

  15. Contribution of aldosterone to cardiovascular and renal inflammation and fibrosis

    PubMed Central

    Brown, Nancy J.

    2014-01-01

    The steroid hormone aldosterone regulates sodium and potassium homeostasis. Aldosterone and activation of the mineralocorticoid receptor also causes inflammation and fibrosis of the heart, fibrosis and remodelling of blood vessels and tubulointerstitial fibrosis and glomerular injury in the kidney. Aldosterone and mineralocorticoid-receptor activation initiate an inflammatory response by increasing the generation of reactive oxygen species by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and mitochondria. High salt intake potentiates these effects, in part by activating the Rho family member Rac1, a regulatory subunit of reduced NADPH oxidase that activates the mineralocorticoid receptor. Studies in mice in which the mineralocorticoid receptor has been deleted from specific cell types suggest a key role for macrophages in promoting inflammation and fibrosis. Aldosterone can exert mineralocorticoid-receptor-independent effects via the angiotensin II receptor and via G-protein-coupled receptor 30. Mineralocorticoid-receptor antagonists are associated with decreased mortality in patients with heart disease and show promise in patients with kidney injury, but can elevate serum potassium concentration. Studies in rodents genetically deficient in aldosterone synthase or treated with a pharmacological aldosterone-synthase inhibitor are providing insight into the relative contribution of aldosterone compared with the contribution of mineralocorticoid-receptor activation in inflammation, fibrosis, and injury. Aldosterone-synthase inhibitors are under development in humans. PMID:23774812

  16. Association of Aldosterone Synthase Polymorphism (CYP11B2 -344T>C) and Genetic Ancestry with Atrial Fibrillation and Serum Aldosterone in African Americans with Heart Failure

    PubMed Central

    Bress, Adam; Han, Jin; Patel, Shitalben R.; Desai, Ankit A.; Mansour, Ibrahim; Groo, Vicki; Progar, Kristin; Shah, Ebony; Stamos, Thomas D.; Wing, Coady; Garcia, Joe G. N.; Kittles, Rick; Cavallari, Larisa H.

    2013-01-01

    The objective of this study was to examine the extent to which aldosterone synthase genotype (CYP11B2) and genetic ancestry correlate with atrial fibrillation (AF) and serum aldosterone in African Americans with heart failure. Clinical data, echocardiographic measurements, and a genetic sample for determination of CYP11B2 -344T>C (rs1799998) genotype and genetic ancestry were collected from 194 self-reported African Americans with chronic, ambulatory heart failure. Genetic ancestry was determined using 105 autosomal ancestry informative markers. In a sub-set of patients (n = 126), serum was also collected for determination of circulating aldosterone. The CYP11B2 −344C allele frequency was 18% among the study population, and 19% of patients had AF. Multiple logistic regression revealed that the CYP11B2 −344CC genotype was a significant independent predictor of AF (OR 12.7, 95% CI 1.60–98.4, p = 0.0150, empirical p = 0.011) while holding multiple clinical factors, left atrial size, and percent European ancestry constant. Serum aldosterone was significantly higher among patients with AF (p = 0.036), whereas increased West African ancestry was inversely correlated with serum aldosterone (r = −0.19, p = 0.037). The CYP11B2 −344CC genotype was also overrepresented among patients with extreme aldosterone elevation (≥90th percentile, p = 0.0145). In this cohort of African Americans with chronic ambulatory heart failure, the CYP11B2 −344T>C genotype was a significant independent predictor of AF while holding clinical, echocardiographic predictors, and genetic ancestry constant. In addition, increased West African ancestry was associated with decreased serum aldosterone levels, potentially providing an explanation for the lower risk for AF observed among African Americans. PMID:23936266

  17. Stimulatory Effect of Food Restriction on the Steroidogenesis of Aldosterone in Ovariectomized Rats.

    PubMed

    Kau, Mei-Mei; Yu, Ching-Han; Tsai, Shiow-Chwen; Wang, Jiing-Rong; Wang, Paulus S.

    2017-04-30

    Food or calorie restriction (FR or CR) induces several physiological changes including weight loss, metabolic adaptations, mineral and hormonal changes. However, the effects of FR on aldosterone steroidogenesis in zona glomerulosa (ZG) cells have not been elucidated. Therefore, the present study was designed to investigate the effects of FR on aldosterone secretion and the involved mechanisms in ovariectomized (Ovx) rats. Ovx rats were divided into ad libitum fed (control) and FR groups. The FR rats exhibited decreased body weight, water intake, urine flow, sodium excretion and increased plasma aldosterone in comparison with control rats. FR elevated the basal and angiotensin II-stimulated aldosterone secretion from ZG cells. The conversions of 25-hydroxy-cholesterol to pregnenolone or corticosterone to aldosterone in ZG cells of FR group were greater than that in control group. FR group had a higher protein expression of steroidogenic acute regulatory (StAR) protein in ZG cells. However, there was no different protein expression of cytochrome P450 sidechain cleavage enzyme (P450scc) in ZG cells between control and FR groups. In summary, the increased activities of P450scc and aldosterone synthase as well as the protein expression of StAR protein in ZG cells are involved in the effects of FR on aldosterone steroidogenesis in Ovx rats. We also suggest that the increase of aldosterone might be associated with anti-diuresis and antinatriuresis in FR group. These results are helpful for understanding the role of aldosterone in physiological adaptation and renal sodium conservation during FR.

  18. Adipocyte-Derived Hormone Leptin Is a Direct Regulator of Aldosterone Secretion, Which Promotes Endothelial Dysfunction and Cardiac Fibrosis.

    PubMed

    Huby, Anne-Cécile; Antonova, Galina; Groenendyk, Jake; Gomez-Sanchez, Celso E; Bollag, Wendy B; Filosa, Jessica A; Belin de Chantemèle, Eric J

    2015-12-01

    In obesity, the excessive synthesis of aldosterone contributes to the development and progression of metabolic and cardiovascular dysfunctions. Obesity-induced hyperaldosteronism is independent of the known regulators of aldosterone secretion, but reliant on unidentified adipocyte-derived factors. We hypothesized that the adipokine leptin is a direct regulator of aldosterone synthase (CYP11B2) expression and aldosterone release and promotes cardiovascular dysfunction via aldosterone-dependent mechanisms. Immunostaining of human adrenal cross-sections and adrenocortical cells revealed that adrenocortical cells coexpress CYP11B2 and leptin receptors. Measurements of adrenal CYP11B2 expression and plasma aldosterone levels showed that increases in endogenous (obesity) or exogenous (infusion) leptin dose-dependently raised CYP11B2 expression and aldosterone without elevating plasma angiotensin II, potassium or corticosterone. Neither angiotensin II receptors blockade nor α and β adrenergic receptors inhibition blunted leptin-induced aldosterone secretion. Identical results were obtained in cultured adrenocortical cells. Enhanced leptin signaling elevated CYP11B2 expression and plasma aldosterone, whereas deficiency in leptin or leptin receptors blunted obesity-induced increases in CYP11B2 and aldosterone, ruling out a role for obesity per se. Leptin increased intracellular calcium, elevated calmodulin and calmodulin-kinase II expression, whereas calcium chelation blunted leptin-mediated increases in CYP11B2, in adrenocortical cells. Mineralocorticoid receptor blockade blunted leptin-induced endothelial dysfunction and increases in cardiac fibrotic markers. Leptin is a newly described regulator of aldosterone synthesis that acts directly on adrenal glomerulosa cells to increase CYP11B2 expression and enhance aldosterone production via calcium-dependent mechanisms. Furthermore, leptin-mediated aldosterone secretion contributes to cardiovascular disease by promoting

  19. Transcriptome Pathway Analysis of Pathological and Physiological Aldosterone-Producing Human Tissues.

    PubMed

    Zhou, Junhua; Lam, Brian; Neogi, Sudeshna G; Yeo, Giles S H; Azizan, Elena A B; Brown, Morris J

    2016-12-01

    Primary aldosteronism is present in ≈10% of hypertensives. We previously performed a microarray assay on aldosterone-producing adenomas and their paired zona glomerulosa and fasciculata. Confirmation of top genes validated the study design and functional experiments of zona glomerulosa selective genes established the role of the encoded proteins in aldosterone regulation. In this study, we further analyzed our microarray data using AmiGO 2 for gene ontology enrichment and Ingenuity Pathway Analysis to identify potential biological processes and canonical pathways involved in pathological and physiological aldosterone regulation. Genes differentially regulated in aldosterone-producing adenoma and zona glomerulosa were associated with steroid metabolic processes gene ontology terms. Terms related to the Wnt signaling pathway were enriched in zona glomerulosa only. Ingenuity Pathway Analysis showed "NRF2-mediated oxidative stress response pathway" and "LPS (lipopolysaccharide)/IL-1 (interleukin-1)-mediated inhibition of RXR (retinoid X receptor) function" were affected in both aldosterone-producing adenoma and zona glomerulosa with associated genes having up to 21- and 8-fold differences, respectively. Comparing KCNJ5-mutant aldosterone-producing adenoma, zona glomerulosa, and zona fasciculata samples with wild-type samples, 138, 56, and 59 genes were differentially expressed, respectively (fold-change >2; P<0.05). ACSS3, encoding the enzyme that synthesizes acetyl-CoA, was the top gene upregulated in KCNJ5-mutant aldosterone-producing adenoma compared with wild-type. NEFM, a gene highly upregulated in zona glomerulosa, was upregulated in KCNJ5 wild-type aldosterone-producing adenomas. NR4A2, the transcription factor for aldosterone synthase, was highly expressed in zona fasciculata adjacent to a KCNJ5-mutant aldosterone-producing adenoma. Further interrogation of these genes and pathways could potentially provide further insights into the pathology of primary

  20. Expression of Angiotensin II and Aldosterone in Radiation-induced Lung Injury.

    PubMed

    Cao, Shuo; Wu, Rong

    2012-12-01

    Radiation-induced lung injury (RILI) is the most common, dose-limiting complication in thoracic malignancy radiotherapy. Considering its negative impact on patients and restrictions to efficacy, the mechanism of RILI was studied. Wistar rats were locally irradiated with a single dose of 0, 16, and 20 Gy to the right half of the lung to establish a lung injury model. Two and six months after irradiation, the right half of the rat lung tissue was removed, and the concentrations of TGF-β1, angiotensin II, and aldosterone were determined via enzyme-linked immunosorbent assay. Statistical differences were observed in the expression levels of angiotensin II and aldosterone between the non-irradiation and irradiation groups. Moreover, the expression level of the angiotensin II-aldosterone system increased with increasing doses, and the difference was still observed as time progressed. Angiotensin II-aldosterone system has an important pathophysiological function in the progression of RILI.

  1. Aldosterone-stimulating somatic gene mutations are common in normal adrenal glands

    PubMed Central

    Nishimoto, Koshiro; Tomlins, Scott A.; Kuick, Rork; Cani, Andi K.; Giordano, Thomas J.; Hovelson, Daniel H.; Liu, Chia-Jen; Sanjanwala, Aalok R.; Edwards, Michael A.; Gomez-Sanchez, Celso E.; Nanba, Kazutaka; Rainey, William E.

    2015-01-01

    Primary aldosteronism (PA) represents the most common cause of secondary hypertension, but little is known regarding its adrenal cellular origins. Recently, aldosterone-producing cell clusters (APCCs) with high expression of aldosterone synthase (CYP11B2) were found in both normal and PA adrenal tissue. PA-causing aldosterone-producing adenomas (APAs) harbor mutations in genes encoding ion channels/pumps that alter intracellular calcium homeostasis and cause renin-independent aldosterone production through increased CYP11B2 expression. Herein, we hypothesized that APCCs have APA-related aldosterone-stimulating somatic gene mutations. APCCs were studied in 42 normal adrenals from kidney donors. To clarify APCC molecular characteristics, we used microarrays to compare the APCC transcriptome with conventional adrenocortical zones [zona glomerulosa (ZG), zona fasciculata, and zona reticularis]. The APCC transcriptome was most similar to ZG but with an enhanced capacity to produce aldosterone. To determine if APCCs harbored APA-related mutations, we performed targeted next generation sequencing of DNA from 23 APCCs and adjacent normal adrenal tissue isolated from both formalin-fixed, paraffin-embedded, and frozen tissues. Known aldosterone driver mutations were identified in 8 of 23 (35%) APCCs, including mutations in calcium channel, voltage-dependent, L-type, α1D-subunit (CACNA1D; 6 of 23 APCCs) and ATPase, Na+/K+ transporting, α1-polypeptide (ATP1A1; 2 of 23 APCCs), which were not observed in the adjacent normal adrenal tissue. Overall, we show three major findings: (i) APCCs are common in normal adrenals, (ii) APCCs harbor somatic mutations known to cause excess aldosterone production, and (iii) the mutation spectrum of aldosterone-driving mutations is different in APCCs from that seen in APA. These results provide molecular support for APCC as a precursor of PA. PMID:26240369

  2. Effect of aldosterone on cochlear Af9 expression and hearing in guinea pig.

    PubMed

    Qin, Li; Zhang, Biyun; Wang, Qianying; Li, Duanchao; Luo, Xiaoli; Zhong, Shixun

    2017-09-01

    Af9 protein in cochlea may be closely related to endolymph regulation by aldosterone and thus may be involved in pathogenesis of endolymphatic hydrops (EH). EH is the pathological characteristic of Ménière's disease (MD). Aldosterone could induce EH, but its relationship with MD is still controversial. The aim of the present study is to investigate the Af9 protein expression in guinea pig cochlea and regulation of Af9 expression and cochlear function by aldosterone. The role of Af9 in pathogenesis of EH is discussed. Thirty guinea pigs were randomly divided into two groups. The treatment group was intraperitoneally injected with aldosterone 0.1 mg/kg/d for 5 days, while the control group was done with saline. Hearing and histomorphology of cochlea were examined. In addition, expression of Af9 protein was studied. The hearing threshold of the treatment group was increased. EH was induced in 73% of guinea pigs in the treatment group, and no EH was found in the control group. Af9 protein was found in spiral limbus, stria vascularis, Reissner's membrane, organ of Corti and spiral ganglion in both groups. Af9 expression in cochlea decreased significantly at protein level after treatment by aldosterone.

  3. Aldosterone and cardiovascular disease: the heart of the matter

    PubMed Central

    He, B. Julie; Anderson, Mark E.

    2012-01-01

    Aldosterone contributes to the endocrine basis of heart failure and studies on cardiac aldosterone signaling have reinforced its value as a therapeutic target. Recent focus has shifted to new roles of aldosterone that appear to depend on co-existing pathologic stimuli, cell type, and disease etiology. This review evaluates recent advances in mechanisms underlying aldosterone-induced cardiac disease and highlights the interplay between aldosterone and Ca2+ and calmodulin dependent protein kinase II, whose hyperactivity during heart failure contributes to disease progression. Increasing evidence implicates aldosterone in diastolic dysfunction, and there is need to develop more targeted therapeutics such as aldosterone synthase inhibitors and molecularly specific anti-oxidants. Despite accumulating knowledge, many questions still persist and will likely dictate areas of future research. PMID:23040074

  4. Antiaging Gene Klotho Regulates Adrenal CYP11B2 Expression and Aldosterone Synthesis

    PubMed Central

    Zhou, Xiaoli; Chen, Kai; Wang, Yongjun; Schuman, Mariano; Lei, Han

    2016-01-01

    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. PMID:26471128

  5. Antiaging Gene Klotho Regulates Adrenal CYP11B2 Expression and Aldosterone Synthesis.

    PubMed

    Zhou, Xiaoli; Chen, Kai; Wang, Yongjun; Schuman, Mariano; Lei, Han; Sun, Zhongjie

    2016-06-01

    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. Copyright © 2016 by the American Society of Nephrology.

  6. Regulation of aldosterone secretion by mineralocorticoid receptor-mediated signaling.

    PubMed

    Chong, Cherish; Hamid, Anis; Yao, Tham; Garza, Amanda E; Pojoga, Luminita H; Adler, Gail K; Romero, Jose R; Williams, Gordon H

    2017-03-01

    We posit the existence of a paracrine/autocrine negative feedback loop, mediated by the mineralocorticoid receptor (MR), regulating aldosterone secretion. To assess this hypothesis, we asked whether altering MR activity in zona glomerulosa (ZG) cells affects aldosterone production. To this end, we studied ex vivo ZG cells isolated from male Wistar rats fed chow containing either high (1.6% Na + (HS)) or low (0.03% Na + (LS)) amount of sodium. Western blot analyses demonstrated that MR was present in both the ZG and zona fasciculata/zona reticularis (ZF/ZR/ZR). In ZG cells isolated from rats on LS chow, MR activation by fludrocortisone produced a 20% and 60% reduction in aldosterone secretion basally and in response to angiotensin II (ANGII) stimulation, respectively. Corticosterone secretion was increased in these cells suggesting that aldosterone synthase activity was being reduced by fludrocortisone. In contrast, canrenoic acid, an MR antagonist, enhanced aldosterone production by up to 30% both basally and in response to ANGII. Similar responses were observed in ZG cells from rats fed HS. Modulating glucocorticoid receptor (GR) activity did not alter aldosterone production by ZG cells; however, altering GR activity did modify corticosterone production from ZF/ZR/ZR cells both basally and in response to adrenocorticotropic hormone (ACTH). Additionally, activating the MR in ZF/ZR/ZR cells strikingly reduced corticosterone secretion. In summary, these data support the hypothesis that negative ultra-short feedback loops regulate adrenal steroidogenesis. In the ZG, aldosterone secretion is regulated by the MR, but not the GR, an effect that appears to be secondary to a change in aldosterone synthase activity. © 2017 Society for Endocrinology.

  7. Very low-density lipoprotein (VLDL)-induced signals mediating aldosterone production.

    PubMed

    Tsai, Ying-Ying; Rainey, William E; Bollag, Wendy B

    2017-02-01

    Aldosterone, secreted by the adrenal zona glomerulosa, enhances sodium retention, thus increasing blood volume and pressure. Excessive production of aldosterone results in high blood pressure and contributes to cardiovascular and renal disease, stroke and visual loss. Hypertension is also associated with obesity, which is correlated with other serious health risks as well. Although weight gain is associated with increased blood pressure, the mechanism by which excess fat deposits increase blood pressure remains unclear. Several studies have suggested that aldosterone levels are elevated with obesity and may represent a link between obesity and hypertension. In addition to hypertension, obese patients typically have dyslipidemia, including elevated serum levels of very low-density lipoprotein (VLDL). VLDL, which functions to transport triglycerides from the liver to peripheral tissues, has been demonstrated to stimulate aldosterone production. Recent studies suggest that the signaling pathways activated by VLDL are similar to those utilized by AngII. Thus, VLDL increases cytosolic calcium levels and stimulates phospholipase D (PLD) activity to result in the induction of steroidogenic acute regulatory (StAR) protein and aldosterone synthase (CYP11B2) expression. These effects seem to be mediated by the ability of VLDL to increase the phosphorylation (activation) of their regulatory transcription factors, such as the cAMP response element-binding (CREB) protein family of transcription factors. Thus, research into the pathways by which VLDL stimulates aldosterone production may identify novel targets for the development of therapies for the treatment of hypertension, particularly those associated with obesity, and other aldosterone-modulated pathologies. © 2017 Society for Endocrinology.

  8. Small-Conductance Ca2+-Activated Potassium Channels Negatively Regulate Aldosterone Secretion in Human Adrenocortical Cells.

    PubMed

    Yang, Tingting; Zhang, Hai-Liang; Liang, Qingnan; Shi, Yingtang; Mei, Yan-Ai; Barrett, Paula Q; Hu, Changlong

    2016-09-01

    Aldosterone, which plays a key role in maintaining water and electrolyte balance, is produced by zona glomerulosa cells of the adrenal cortex. Autonomous overproduction of aldosterone from zona glomerulosa cells causes primary hyperaldosteronism. Recent clinical studies have highlighted the pathological role of the KCNJ5 potassium channel in primary hyperaldosteronism. Our objective was to determine whether small-conductance Ca(2+)-activated potassium (SK) channels may also regulate aldosterone secretion in human adrenocortical cells. We found that apamin, the prototypic inhibitor of SK channels, decreased membrane voltage, raised intracellular Ca(2+) and dose dependently increased aldosterone secretion from human adrenocortical H295R cells. By contrast, 1-Ethyl-2-benzimidazolinone, an agonist of SK channels, antagonized apamin's action and decreased aldosterone secretion. Commensurate with an increase in aldosterone production, apamin increased mRNA expression of steroidogenic acute regulatory protein and aldosterone synthase that control the early and late rate-limiting steps in aldosterone biosynthesis, respectively. In addition, apamin increased angiotensin II-stimulated aldosterone secretion, whereas 1-Ethyl-2-benzimidazolinone suppressed both angiotensin II- and high K(+)-stimulated production of aldosterone in H295R cells. These findings were supported by apamin-modulation of basal and angiotensin II-stimulated aldosterone secretion from acutely prepared slices of human adrenals. We conclude that SK channel activity negatively regulates aldosterone secretion in human adrenocortical cells. Genetic association studies are necessary to determine whether mutations in SK channel subtype 2 genes may also drive aldosterone excess in primary hyperaldosteronism. © 2016 American Heart Association, Inc.

  9. Subchronic treatment with aldosterone induces depression-like behaviours and gene expression changes relevant to major depressive disorder.

    PubMed

    Hlavacova, Natasa; Wes, Paul D; Ondrejcakova, Maria; Flynn, Marianne E; Poundstone, Patricia K; Babic, Stanislav; Murck, Harald; Jezova, Daniela

    2012-03-01

    The potential role of aldosterone in the pathophysiology of depression is unclear. The aim of this study was to test the hypothesis that prolonged elevation of circulating aldosterone induces depression-like behaviour accompanied by disease-relevant changes in gene expression in the hippocampus. Subchronic (2-wk) treatment with aldosterone (2 μg/100 g body weight per day) or vehicle via subcutaneous osmotic minipumps was used to induce hyperaldosteronism in male rats. All rats (n = 20/treatment group) underwent a modified sucrose preference test. Half of the animals from each treatment group were exposed to the forced swim test (FST), which served both as a tool to assess depression-like behaviour and as a stress stimulus. Affymetrix microarray analysis was used to screen the entire rat genome for gene expression changes in the hippocampus. Aldosterone treatment induced an anhedonic state manifested by decreased sucrose preference. In the FST, depressogenic action of aldosterone was manifested by decreased latency to immobility and increased time spent immobile. Aldosterone treatment resulted in transcriptional changes of genes in the hippocampus involved in inflammation, glutamatergic activity, and synaptic and neuritic remodelling. Furthermore, aldosterone-regulated genes substantially overlapped with genes affected by stress in the FST. This study demonstrates the existence of a causal relationship between the hyperaldosteronism and depressive behaviour. In addition, aldosterone treatment induced changes in gene expression that may be relevant to the aetiology of major depressive disorder. Subchronic treatment with aldosterone represents a new animal model of depression, which may contribute to the development of novel targets for the treatment of depression.

  10. RGS2 is regulated by angiotensin II and functions as a negative feedback of aldosterone production in H295R human adrenocortical cells.

    PubMed

    Romero, Damian G; Plonczynski, Maria W; Gomez-Sanchez, Elise P; Yanes, Licy L; Gomez-Sanchez, Celso E

    2006-08-01

    Regulator of G protein signaling (RGS) proteins interact with Galpha-subunits of heterotrimeric G proteins, accelerating the rate of GTP hydrolysis and finalizing the intracellular signaling triggered by the G protein-coupled receptor-ligand interaction. Angiotensin (Ang) II interacts with its G protein-coupled receptor in zona glomerulosa adrenal cells and triggers a cascade of intracellular signals that regulates steroidogenesis and proliferation. We studied Ang II-mediated regulation of RGS2, the role of RGS2 in steroidogenesis, and the intracellular signal events involved in H295R human adrenal cells. We report that both H295R cells and human adrenal gland express RGS2 mRNA. In H295R cells, Ang II caused a rapid and transient increase in RGS2 mRNA levels quantified by real-time RT-PCR. Ang II effects were mimicked by calcium ionophore A23187 and blocked by calcium channel blocker nifedipine. Ang II effects also were blocked by calmodulin antagonists (W-7 and calmidazolium) and calcium/calmodulin-dependent kinase antagonist KN-93. RGS2 overexpression by retroviral infection in H295R cells caused a decrease in Ang II-stimulated aldosterone secretion but did not modify cortisol secretion. In reporter assays, RGS2 decreased Ang II-mediated aldosterone synthase up-regulation. These results suggest that Ang II up-regulates RGS2 mRNA by the calcium/calmodulin-dependent kinase pathway in H295R cells. RGS2 overexpression specifically decreases aldosterone secretion through a decrease in Ang II-mediated aldosterone synthase-induced expression. In conclusion, RGS2 expression is induced by Ang II to terminate the intracellular signaling cascade generated by Ang II. RGS2 alterations in expression levels or functionality could be implicated in deregulations of Ang II signaling and abnormal aldosterone secretion by the adrenal gland.

  11. Effects of ACTH, dexamethasone, and adrenalectomy on 11β-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) gene expression in the rat central nervous system

    PubMed Central

    Ye, Ping; Kenyon, Christopher J; MacKenzie, Scott M; Nichol, Katherine; Seckl, Jonathan R; Fraser, Robert; Connell, John M C; Davies, Eleanor

    2008-01-01

    Using a highly sensitive quantitative RT-PCR method for the measurement of CYP11B1 (11β-hydroxylase) and CYP11B2 (aldosterone synthase) mRNAs, we previously demonstrated that CYP11B2 expression in the central nervous system (CNS) is subject to regulation by dietary sodium. We have now quantified the expression of these genes in the CNS of male Wistar Kyoto (WKY) rats in response to systemic ACTH infusion, dexamethasone infusion, and to adrenalectomy. CYP11B1 and CYP11B2 mRNA levels were measured in total RNA isolated from the adrenal gland and discrete brain regions using real-time quantitative RT-PCR. ACTH infusion (40 ng/day for 7 days, N=8) significantly increased CYP11B1 mRNA in the adrenal gland, hypothalamus, and cerebral cortex compared with animals infused with vehicle only. ACTH infusion decreased adrenal CYP11B2 expression but increased expression in all of the CNS regions except the cortex. Dexamethasone (10 μg/day for 7 days, N=8) reduced adrenal CYP11B1 mRNA compared with control animals but had no significant effect on either gene's expression in the CNS. Adrenalectomy (N=6 per group) significantly increased CYP11B1 expression in the hippocampus and hypothalamus and raised CYP11B2 expression in the cerebellum relative to sham-operated animals. This study confirms the transcription of CYP11B1 and CYP11B2 throughout the CNS and demonstrates that gene transcription is subject to differential regulation by ACTH and circulating corticosteroid levels. PMID:18252953

  12. Renal denervation attenuates aldosterone expression and associated cardiovascular pathophysiology in angiotensin II-induced hypertension.

    PubMed

    Hong, Mo-Na; Li, Xiao-Dong; Chen, Dong-Rui; Ruan, Cheng-Chao; Xu, Jian-Zhong; Chen, Jing; Wu, Yong-Jie; Ma, Yu; Zhu, Ding-Liang; Gao, Ping-Jin

    2016-10-18

    The sympathetic nervous system interacts with the renin-angiotensin-aldosterone system (RAAS) contributing to cardiovascular diseases. In this study, we sought to determine if renal denervation (RDN) inhibits aldosterone expression and associated cardiovascular pathophysiological changes in angiotensin II (Ang II)-induced hypertension. Bilateral RDN or SHAM operation was performed before chronic 14-day Ang II subcutaneous infusion (200ng/kg/min) in male Sprague-Dawley rats. Bilateral RDN blunted Ang II-induced hypertension and ameliorated the mesenteric vascular dysfunction. Cardiovascular hypertrophy in response to Ang II was significantly attenuated by RDN as shown by histopathology and transthoracic echocardiography. Moreover, Ang II-induced vascular and myocardial inflammation and fibrosis were suppressed by RDN with concurrent decrease in fibronectin and collagen deposition, macrophage infiltration, and MCP-1 expression. Interestingly, RDN also inhibited Ang II-induced aldosterone expression in the plasma, kidney and heart. This was associated with the reduction of calcitonin gene-related peptide (CGRP) in the adrenal gland. Ang II promoted aldosterone secretion which was partly attenuated by CGRP in the adrenocortical cell line, suggesting a protective role of CGRP in this model. Activation of transforming growth factor-β (TGF-β)/Smad and mitogen-activated protein kinases (MAPKs) signaling pathway was both inhibited by RDN especially in the heart. These results suggest that the regulation of the renal sympathetic nerve in Ang II-induced hypertension and associated cardiovascular pathophysiological changes is likely mediated by aldosterone, with CGRP involvement.

  13. Renal denervation attenuates aldosterone expression and associated cardiovascular pathophysiology in angiotensin II-induced hypertension

    PubMed Central

    Chen, Dong-Rui; Ruan, Cheng-Chao; Xu, Jian-Zhong; Chen, Jing; Wu, Yong-Jie; Ma, Yu; Zhu, Ding-Liang; Gao, Ping-Jin

    2016-01-01

    The sympathetic nervous system interacts with the renin-angiotensin-aldosterone system (RAAS) contributing to cardiovascular diseases. In this study, we sought to determine if renal denervation (RDN) inhibits aldosterone expression and associated cardiovascular pathophysiological changes in angiotensin II (Ang II)-induced hypertension. Bilateral RDN or SHAM operation was performed before chronic 14-day Ang II subcutaneous infusion (200ng/kg/min) in male Sprague-Dawley rats. Bilateral RDN blunted Ang II-induced hypertension and ameliorated the mesenteric vascular dysfunction. Cardiovascular hypertrophy in response to Ang II was significantly attenuated by RDN as shown by histopathology and transthoracic echocardiography. Moreover, Ang II-induced vascular and myocardial inflammation and fibrosis were suppressed by RDN with concurrent decrease in fibronectin and collagen deposition, macrophage infiltration, and MCP-1 expression. Interestingly, RDN also inhibited Ang II-induced aldosterone expression in the plasma, kidney and heart. This was associated with the reduction of calcitonin gene-related peptide (CGRP) in the adrenal gland. Ang II promoted aldosterone secretion which was partly attenuated by CGRP in the adrenocortical cell line, suggesting a protective role of CGRP in this model. Activation of transforming growth factor-β (TGF-β)/Smad and mitogen-activated protein kinases (MAPKs) signaling pathway was both inhibited by RDN especially in the heart. These results suggest that the regulation of the renal sympathetic nerve in Ang II-induced hypertension and associated cardiovascular pathophysiological changes is likely mediated by aldosterone, with CGRP involvement. PMID:27661131

  14. Expression and biochemical characteristics of two different aldosterone receptors in both healthy and dilated cardiomyopathy dog heart tissue.

    PubMed

    Reynoso Palomar, Alejandro R; Rodriguez Bravo, Moncerrat; Villa Mancera, Abel E; Mucha, Carlos J

    2017-03-01

    Recently, replicates of the aldosterone receptor expression have been done in healthy heart dog tissues through immunohistochemistry, showing an apparent heterogeneous distribution in the four chambers. Recent studies have also identified immediate effects of aldosterone, suggesting aldosterone also produces non-genomic effects caused by an unidentified receptor. In order to study the molecular and quantitative expression characteristics of aldosterone binding receptors in the canine heart, we conducted studies, using Western Blot, in the heart from both healthy animals and animals with dilated cardiomyopathy. The results show the presence and distribution of two aldosterone receptors; one of 110/120 kDa molecular weight, suggested as cytosolic/nuclear and the other of undetermined location with a 250 kDa molecular weight.

  15. Aberrant gonadotropin-releasing hormone receptor (GnRHR) expression and its regulation of CYP11B2 expression and aldosterone production in adrenal aldosterone-producing adenoma (APA).

    PubMed

    Nakamura, Yasuhiro; Hattangady, Namita G; Ye, Ping; Satoh, Fumitoshi; Morimoto, Ryo; Ito-Saito, Takako; Sugawara, Akira; Ohba, Koji; Takahashi, Kazuhiro; Rainey, William E; Sasano, Hironobu

    2014-03-25

    Aberrant expression of gonadotropin-releasing hormone receptor (GnRHR) has been reported in human adrenal tissues including aldosterone-producing adenoma (APA). However, the details of its expression and functional role in adrenals are still not clear. In this study, quantitative RT-PCR analysis revealed the mean level of GnRHR mRNA was significantly higher in APAs than in human normal adrenal (NA) (P=0.004). GnRHR protein expression was detected in human NA and neoplastic adrenal tissues. In H295R cells transfected with GnRHR, treatment with GnRH resulted in a concentration-dependent increase in CYP11B2 reporter activity. Chronic activation of GnRHR with GnRH (100nM), in a cell line with doxycycline-inducible GnRHR (H295R-TR/GnRHR), increased CYP11B2 expression and aldosterone production. These agonistic effects were inhibited by blockers for the calcium signaling pathway, KN93 and calmidazolium. These results suggest GnRH, through heterotopic expression of its receptor, may be a potential regulator of CYP11B2 expression levels in some cases of APA. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  16. Macrolides selectively inhibit mutant KCNJ5 potassium channels that cause aldosterone-producing adenoma

    PubMed Central

    Scholl, Ute I.; Abriola, Laura; Zhang, Chengbiao; Reimer, Esther N.; Plummer, Mark; Zhang, Junhui; Hoyer, Denton; Merkel, Jane S.; Wang, Wenhui; Lifton, Richard P.

    2017-01-01

    Aldosterone-producing adenomas (APAs) are benign tumors of the adrenal gland that constitutively produce the salt-retaining steroid hormone aldosterone and cause millions of cases of severe hypertension worldwide. Either of 2 somatic mutations in the potassium channel KCNJ5 (G151R and L168R, hereafter referred to as KCNJ5MUT) in adrenocortical cells account for half of APAs worldwide. These mutations alter channel selectivity to allow abnormal Na+ conductance, resulting in membrane depolarization, calcium influx, aldosterone production, and cell proliferation. Because APA diagnosis requires a difficult invasive procedure, patients often remain undiagnosed and inadequately treated. Inhibitors of KCNJ5MUT could allow noninvasive diagnosis and therapy of APAs carrying KCNJ5 mutations. Here, we developed a high-throughput screen for rescue of KCNJ5MUT-induced lethality and identified a series of macrolide antibiotics, including roxithromycin, that potently inhibit KCNJ5MUT, but not KCNJ5WT. Electrophysiology demonstrated direct KCNJ5MUT inhibition. In human aldosterone-producing adrenocortical cancer cell lines, roxithromycin inhibited KCNJ5MUT-induced induction of CYP11B2 (encoding aldosterone synthase) expression and aldosterone production. Further exploration of macrolides showed that KCNJ5MUT was similarly selectively inhibited by idremcinal, a macrolide motilin receptor agonist, and by synthesized macrolide derivatives lacking antibiotic or motilide activity. Macrolide-derived selective KCNJ5MUT inhibitors thus have the potential to advance the diagnosis and treatment of APAs harboring KCNJ5MUT. PMID:28604387

  17. Macrolides selectively inhibit mutant KCNJ5 potassium channels that cause aldosterone-producing adenoma.

    PubMed

    Scholl, Ute I; Abriola, Laura; Zhang, Chengbiao; Reimer, Esther N; Plummer, Mark; Kazmierczak, Barbara I; Zhang, Junhui; Hoyer, Denton; Merkel, Jane S; Wang, Wenhui; Lifton, Richard P

    2017-06-30

    Aldosterone-producing adenomas (APAs) are benign tumors of the adrenal gland that constitutively produce the salt-retaining steroid hormone aldosterone and cause millions of cases of severe hypertension worldwide. Either of 2 somatic mutations in the potassium channel KCNJ5 (G151R and L168R, hereafter referred to as KCNJ5MUT) in adrenocortical cells account for half of APAs worldwide. These mutations alter channel selectivity to allow abnormal Na+ conductance, resulting in membrane depolarization, calcium influx, aldosterone production, and cell proliferation. Because APA diagnosis requires a difficult invasive procedure, patients often remain undiagnosed and inadequately treated. Inhibitors of KCNJ5MUT could allow noninvasive diagnosis and therapy of APAs carrying KCNJ5 mutations. Here, we developed a high-throughput screen for rescue of KCNJ5MUT-induced lethality and identified a series of macrolide antibiotics, including roxithromycin, that potently inhibit KCNJ5MUT, but not KCNJ5WT. Electrophysiology demonstrated direct KCNJ5MUT inhibition. In human aldosterone-producing adrenocortical cancer cell lines, roxithromycin inhibited KCNJ5MUT-induced induction of CYP11B2 (encoding aldosterone synthase) expression and aldosterone production. Further exploration of macrolides showed that KCNJ5MUT was similarly selectively inhibited by idremcinal, a macrolide motilin receptor agonist, and by synthesized macrolide derivatives lacking antibiotic or motilide activity. Macrolide-derived selective KCNJ5MUT inhibitors thus have the potential to advance the diagnosis and treatment of APAs harboring KCNJ5MUT.

  18. Thrombospondin expression in aldosterone-producing adenomas.

    PubMed

    Hatakeyama, Haruhiko; Nishizawa, Makoto; Nakagawa, Atsushi; Nakano, Shigeru; Kigoshi, Toshikazu; Miyamori, Isamu; Uchida, Kenzo

    2002-07-01

    Thrombospondin (TSP) 1 and 2 are extracellular matrix proteins that appear to play a role in cell adhesion and cell migration. It has been demonstrated that the pattern of TSP expression is shifted from TSP1 to TSP2 under adrenocorticotrophic hormone treatment in bovine adrenocortical cells. We investigated the expression in human adrenal tissues by Northern blot analysis and correlated these data with the expression of the adrenocorticotrophic hormone-receptor (ACTH-R). All adrenal tissues (control adrenals, nonfunctional adenomas and ACTH-dependent aldosterone-producing adenomas (APA)) expressed both TSP1 and TSP2 mRNAs. Compared to control adrenals (TSP1 and TSP2 expression = 100 +/- 12%, respectively), TSP1 expression was negatively (51 +/- 10%, p < 0.01) and TSP2 expression was positively (289 +/- 36%, p < 0.01) regulated in APA. No significant differences in TSP1 and TSP2 expressions were found between control adrenals and nonfunctional adenomas. In APA, TSP1 (r = -0.86, p<0.01) and TSP2 (r = 0.88, p < 0.01) expressions correlated closely with the expression of ACTH-R. These results suggest that ACTH activity plays an important role in regulating the expression of TSPs in human adrenal tissues. We speculate that the shift of expression observed in APA may be associated with the phenotype of the tumors.

  19. Aldosterone and the conquest of land.

    PubMed

    Colombo, L; Dalla Valle, L; Fiore, C; Armanini, D; Belvedere, P

    2006-04-01

    The sequence of the phylogenetic events that preceded the appearance of aldosterone in vertebrates is described, starting from the ancestral conversion of cytochrome P450s from oxygen detoxification to xenobiotic detoxification and synthesis of oxygenated endobiotics with useful functions in intercellular signalling, such as steroid hormones. At the end of the Silurian period [438-408 million yr ago, (Mya)], a complete set of cytochrome P450s for corticoid synthesis was presumably already available, except for mitochondrial cytochrome P450c18 or aldosterone synthase encoded by CYP11B2. This gene arose by duplication of the CYP11B gene in the sarcopterygian or lobe-finned fish/tetrapod line after its divergence from the actinopterygian or ray-finned fish line 420 Mya, but before the beginning of the colonization of land by tetrapods in the late Devonian period, around 370 Mya. The fact that aldosterone is already present in Dipnoi, which occupy an evolutionary transition between water- and air-breathing but are fully aquatic, suggests that the role of this steroid was to potentiate the corticoid response to hypoxia, rather than to prevent dehydration out of the water. In terrestrial amphibians, there is no differentiation between the secretion rates and gluco- and mineralocorticoid effects of aldosterone and corticosterone. In sauropsids, plasma aldosterone concentrations are much lower than in amphibians, but regulation of salt/water balance is dependent upon both aldosterone and corticosterone, though sometimes with opposed actions. In terrestrial mammals, aldosterone acquires a specific mineralocorticoid function, because its interaction with the mineralocorticoid receptor is protected by the coexpression of the enzyme 11beta-hydroxysteroid dehydrogenase type 2, which inactivates both cortisol and corticosterone. There is evidence that aldosterone can be also synthesized extra-adrenally in brain neurons and cardiac myocytes, which lack this protection and where

  20. Regulation of aldosterone production by ion channels: From basal secretion to primary aldosteronism.

    PubMed

    Yang, Tingting; He, Min; Hu, Changlong

    2018-03-01

    Aldosterone is produced by zona glomerulosa (ZG) cells of the adrenal cortex and plays a key role in balancing water and electrolytes levels. Autonomous overproduction of aldosterone leads to primary aldosteronism (PA), which is the most common form of secondary endocrine hypertension. Recently, significant progress has been made towards understanding the genetic basis of PA, where increasing clinical evidence suggests that mutations in ion channels appear to be the major cause of aldosterone-producing adenomas. In this review, we focused on potassium and calcium channels that regulate aldosterone secretion, and their roles in the pathology of PA. Because potassium and calcium channels are differentially expressed in ZG cells in different species of mammals, the limitations of published studies are also discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Vascular effects of aldosterone: sorting out the receptors and the ligands.

    PubMed

    Feldman, Ross D; Gros, Robert

    2013-12-01

    Aldosterone has actions far beyond its role as a renal regulator of sodium reabsorption, and broader mechanisms of action than simply a transcriptional regulator. Aldosterone has a number of vascular effects, including regulation of vascular reactivity and vascular growth and/or development. Aldosterone-mediated effects on vascular reactivity reflect a balance between its endothelial-dependent vasodilator effects and its direct smooth muscle vasoconstrictor effects. The endothelial vasodilator effects of aldosterone are mediated by phosphatidylinositol 3-kinase-dependent activation of nitric oxide synthase. G-Protein oestrogen receptor (GPER) is a recently recognized G-protein coupled receptor (GPCR) that is activated by steroid hormones. It was first recognized as the GPCR mediating the rapid effects of oestrogens. Activation of GPER also mediates at least some of the vascular effects of aldosterone in smooth muscle and endothelial cells. In vascular endothelial cells, aldosterone activation of GPER mediates vasodilation. In contrast, activation of endothelial mineralocorticoid receptors has been linked to enhanced vasoconstrictor and/or impaired vasodilator responses. © 2013 Wiley Publishing Asia Pty Ltd.

  2. Renin knockout rat: control of adrenal aldosterone and corticosterone synthesis in vitro and adrenal gene expression

    PubMed Central

    Gehrand, Ashley; Bruder, Eric D.; Hoffman, Matthew J.; Engeland, William C.; Moreno, Carol

    2014-01-01

    The classic renin-angiotensin system is partly responsible for controlling aldosterone secretion from the adrenal cortex via the peptide angiotensin II (ANG II). In addition, there is a local adrenocortical renin-angiotensin system that may be involved in the control of aldosterone synthesis in the zona glomerulosa (ZG). To characterize the long-term control of adrenal steroidogenesis, we utilized adrenal glands from renin knockout (KO) rats and compared steroidogenesis in vitro and steroidogenic enzyme expression to wild-type (WT) controls (Dahl S rat). Adrenal capsules (ZG; aldosterone production) and subcapsules [zona reticularis/fasciculata (ZFR); corticosterone production] were separately dispersed and studied in vitro. Plasma renin activity and ANG II concentrations were extremely low in the KO rats. Basal and cAMP-stimulated aldosterone production was significantly reduced in renin KO ZG cells, whereas corticosterone production was not different between WT and KO ZFR cells. As expected, adrenal renin mRNA expression was lower in the renin KO compared with the WT rat. Real-time PCR and immunohistochemical analysis showed a significant decrease in P450aldo (Cyp11b2) mRNA and protein expression in the ZG from the renin KO rat. The reduction in aldosterone synthesis in the ZG of the renin KO adrenal seems to be accounted for by a specific decrease in P450aldo and may be due to the absence of chronic stimulation of the ZG by circulating ANG II or to a reduction in locally released ANG II within the adrenal gland. PMID:25394830

  3. Akt-mediated cardioprotective effects of aldosterone in type 2 diabetic mice.

    PubMed

    Fazal, Loubina; Azibani, Feriel; Bihry, Nicolas; Coutance, Guillaume; Polidano, Evelyne; Merval, Régine; Vodovar, Nicolas; Launay, Jean-Marie; Delcayre, Claude; Samuel, Jane-Lise

    2014-06-01

    Studies have shown that aldosterone would have angiogenic effects and therefore would be beneficial in the context of cardiovascular diseases. We thus investigated the potential involvement of aldosterone in triggering a cardiac angiogenic response in the context of type-2 diabetes and the molecular pathways involved. Male 3-wk-old aldosterone synthase (AS)-overexpressing mice and their control wild-type (WT) littermates were fed a standard or high-fat, high-sucrose (HFHS) diet. After 6 mo of diet treatment, mice were euthanized, and cardiac samples were assayed by RT-PCR, immunoblotting, and immunohistology. HFHS diet induced type-2 diabetes in WT (WT-D) and AS (AS-D) mice. VEGFa mRNAs decreased in WT-D (-43%, P<0.05 vs. WT) and increased in AS-D mice (+236%, P< 0.01 vs. WT-D). In WT-D mouse hearts, the proapoptotic p38MAPK was activated (P<0.05 vs. WT and AS-D), whereas Akt activity decreased (-64%, P<0.05 vs. WT). The AS mice, which exhibited a cardiac up-regulation of IGF1-R, showed an increase in Akt phosphorylation when diabetes was induced (P<0.05 vs. WT and AS-D). Contrary to WT-D mice, AS-D mouse hearts did not express inflammatory markers and exhibited a normal capillary density (P<0.05 vs. WT-D). To our knowledge, this is the first study providing new insights into the mechanisms whereby aldosterone prevents diabetes-induced cardiac disorders. © FASEB.

  4. NADPH Oxidase-Derived H2O2 Contributes to Angiotensin II-Induced Aldosterone Synthesis in Human and Rat Adrenal Cortical Cells

    PubMed Central

    Rajamohan, Senthilkumar B.; Raghuraman, Gayatri; Prabhakar, Nanduri R.

    2012-01-01

    Abstract Background The Renin-Angiotensin-Aldosterone-System plays a pivotal role in hypertension. Angiotensin II (Ang II) is a major regulator of aldosterone synthesis and secretion, and it is known to facilitate reactive oxygen species (ROS) generation in many cell types. Aims: Here, we assessed the role of ROS signaling in Ang II-induced aldosterone synthesis by focusing on the regulation of aldosterone synthase (CYP11B2), a cytochrome P450 oxidase that catalyzes the final step in aldosterone biosynthetic pathway. Results: Ang II increased CYP11B2 activity, mRNA and protein with a concomitant elevation of 6-Carboxy- 2′,7′-dichlorodihydrofluorescein diacetate fluorescence, malondialdehyde and protein carbonyl levels (indices of ROS), NADPH oxidase (Nox) activity, and H2O2 levels in human and rat adrenal cortical cells. The expression of nuclear receptor related 1 protein, a transcription factor known to regulate CYP11B2 expression, was also augmented by Ang II. These Ang II-evoked effects were either abolished or attenuated by pretreatment of cells with either Ang II type I receptor (AT1R) antagonist, or antioxidants or Nox inhibitor or siRNA silencing of Nox1, 2 and 4, or inhibitors of phospholipase C and protein kinase C. Exogenous H2O2 mimicked the facilitatory effects of Ang II on CYP11B2 activity, mRNA, and protein expression, and these changes were significantly reduced by PEG-catalase. Innovation: ROS, particularly H2O2, is identified as a key regulator of aldosterone production. Conclusion: Our results suggest that Ang II facilitates CYP11B2 activity and the ensuing aldosterone production via activation of AT1R-Nox-H2O2 signaling pathway. Antioxid. Redox Signal. 17, 445–459. PMID:22214405

  5. Aldosterone induces clonal β-cell failure through glucocorticoid receptor

    PubMed Central

    Chen, Fang; Liu, Jia; Wang, Yanyang; Wu, Tijun; Shan, Wei; Zhu, Yunxia; Han, Xiao

    2015-01-01

    Aldosterone excess causes insulin resistance in peripheral tissues and directly impairs the function of clonal β-cell. The aim of this study was to investigate the molecular mechanisms involved in the aldosterone-induced impairment of clonal β-cells. As expected, aldosterone induced apoptosis and β-cell dysfunction, including impairment of insulin synthesis and secretion, which were reversed by Glucocorticoid receptor (GR) antagonists or GR-specific siRNA. However, mineralocorticoid receptor (MR) antagonists or MR-specific siRNA had no effect on impairment of clonal β-cells induced by aldosterone. Besides, aldosterone significantly decreased expression and activity of MafA, while activated JNK and p38 MAPK in a GR-dependent manner. In addition, JNK inhibitors (SP600125) and/or p38 inhibitors (SB203580) could abolish the effect of aldosterone on MafA expression and activity. Importantly, overexpression of JNK1 or p38 reversed the protective effect of a GR antagonist on the decrease of MafA expression and activity. Furthermore, aldosterone inhibits MafA expression at the transcriptional and post-transcriptional level through activation of JNK and p38, respectively. Consequently, overexpression of MafA increased synthesis and secretion of insulin, and decreased apoptosis in clonal β-cells exposed to aldosterone. These findings identified aldosterone as an inducer of clonal β-cell failure that operates through the GR-MAPK-MafA signaling pathway. PMID:26287126

  6. Myeloid cells are capable of synthesizing aldosterone to exacerbate damage in muscular dystrophy.

    PubMed

    Chadwick, Jessica A; Swager, Sarah A; Lowe, Jeovanna; Welc, Steven S; Tidball, James G; Gomez-Sanchez, Celso E; Gomez-Sanchez, Elise P; Rafael-Fortney, Jill A

    2016-12-01

    FDA-approved mineralocorticoid receptor (MR) antagonists are used to treat heart failure. We have recently demonstrated efficacy of MR antagonists for skeletal muscles in addition to heart in Duchenne muscular dystrophy mouse models and that mineralocorticoid receptors are present and functional in skeletal muscles. The goal of this study was to elucidate the underlying mechanisms of MR antagonist efficacy on dystrophic skeletal muscles. We demonstrate for the first time that infiltrating myeloid cells clustered in damaged areas of dystrophic skeletal muscles have the capacity to produce the natural ligand of MR, aldosterone, which in excess is known to exacerbate tissue damage. Aldosterone synthase protein levels are increased in leukocytes isolated from dystrophic muscles compared with controls and local aldosterone levels in dystrophic skeletal muscles are increased, despite normal circulating levels. All genes encoding enzymes in the pathway for aldosterone synthesis are expressed in muscle-derived leukocytes. 11β-HSD2, the enzyme that inactivates glucocorticoids to increase MR selectivity for aldosterone, is also increased in dystrophic muscle tissues. These results, together with the demonstrated preclinical efficacy of antagonists, suggest MR activation is in excess of physiological need and likely contributes to the pathology of muscular dystrophy. This study provides new mechanistic insight into the known contribution of myeloid cells to muscular dystrophy pathology. This first report of myeloid cells having the capacity to produce aldosterone may have implications for a wide variety of acute injuries and chronic diseases with inflammation where MR antagonists may be therapeutic. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Mechanisms of Hypertension: The Expanding Role of Aldosterone

    PubMed Central

    FREEL, E. MARIE; CONNELL, JOHN M.C.

    2005-01-01

    Hypertension is a common disorder that affects a large heterogeneous patient population. Subgroups can be identified on the basis of their responses to hormonal and biologic stimuli. These subgroups include low-renin hypertensives and nonmodulators. Aldosterone, the principal human mineralocorticoid, is increasingly recognized as playing a significant role in cardiovascular morbidity, and its role in hypertension has recently been reevaluated with studies that suggest that increased aldosterone biosynthesis (as defined by an elevated aldosterone to renin ratio) is a key phenotype in up to 15% of individuals with hypertension. It was reported previously that a polymorphism of the gene (C to T conversion at position −344) encoding aldosterone synthase is associated with hypertension, particularly in individuals with a high ratio. However, the most consistent association with this variant is a relative impairment of adrenal 11β-hydroxylation. This review explores the evidence for this and provides a hypothesis linking impaired 11β-hydroxylation and hypertension with a raised aldosterone to renin ratio. It is also speculated that there is substantial overlap between this group of patients and previously identified low-renin hypertensives and nonmodulators. Thus, these groups may form a neurohormonal spectrum reflecting different stages of hypertension or indeed form sequential steps in the natural history of hypertension in genetically susceptible individuals. PMID:15284285

  8. Aldosterone Upregulates Transient Receptor Potential Melastatin 7 (TRPM7)*

    PubMed Central

    Valinsky, William C.; Jolly, Anna; Miquel, Perrine

    2016-01-01

    Transient receptor potential melastatin 7 (TRPM7) is a ubiquitously expressed Mg2+-permeable ion channel fused to a C-terminal α-kinase domain. Recently, aldosterone was shown to increase intracellular Mg2+ levels and alter inflammatory signaling in TRPM7-expressing HEK293 cells. This study was undertaken to assess whether these effects were related to an aldosterone-mediated increase of TRPM7 current and/or plasma membrane localization. Using HEK293 cells stably expressing WT-TRPM7, we found that 18-h application of aldosterone significantly increased TRPM7 current and TRPM7 plasma membrane protein expression by 48% and 34%, respectively. The aldosterone-mediated increase of TRPM7 current was inhibited by eplerenone, a mineralocorticoid receptor (MR) blocker, and GSK-650394, an inhibitor of the serum- and glucocorticoid-regulated kinase 1 (SGK1). SGK1 blockade also prevented the aldosterone-induced increase of TRPM7 plasma membrane protein. It was further determined that K1648R-TRPM7, the phosphotransferase-inactive TRPM7 mutant, was unresponsive to aldosterone. Therefore, chronic aldosterone treatment increases the plasma membrane expression of TRPM7, which is associated with an increase of TRPM7 current. This process occurs via an MR-dependent, genomic signaling cascade involving SGK1 and a functioning TRPM7 α-kinase domain. We suggest that this mechanism may be of general relevance when interpreting the effects of aldosterone because the MR receptor is found in multiple tissues, and TRPM7 and SGK1 are ubiquitously expressed. PMID:27466368

  9. Aldosterone Upregulates Transient Receptor Potential Melastatin 7 (TRPM7).

    PubMed

    Valinsky, William C; Jolly, Anna; Miquel, Perrine; Touyz, Rhian M; Shrier, Alvin

    2016-09-16

    Transient receptor potential melastatin 7 (TRPM7) is a ubiquitously expressed Mg(2+)-permeable ion channel fused to a C-terminal α-kinase domain. Recently, aldosterone was shown to increase intracellular Mg(2+) levels and alter inflammatory signaling in TRPM7-expressing HEK293 cells. This study was undertaken to assess whether these effects were related to an aldosterone-mediated increase of TRPM7 current and/or plasma membrane localization. Using HEK293 cells stably expressing WT-TRPM7, we found that 18-h application of aldosterone significantly increased TRPM7 current and TRPM7 plasma membrane protein expression by 48% and 34%, respectively. The aldosterone-mediated increase of TRPM7 current was inhibited by eplerenone, a mineralocorticoid receptor (MR) blocker, and GSK-650394, an inhibitor of the serum- and glucocorticoid-regulated kinase 1 (SGK1). SGK1 blockade also prevented the aldosterone-induced increase of TRPM7 plasma membrane protein. It was further determined that K1648R-TRPM7, the phosphotransferase-inactive TRPM7 mutant, was unresponsive to aldosterone. Therefore, chronic aldosterone treatment increases the plasma membrane expression of TRPM7, which is associated with an increase of TRPM7 current. This process occurs via an MR-dependent, genomic signaling cascade involving SGK1 and a functioning TRPM7 α-kinase domain. We suggest that this mechanism may be of general relevance when interpreting the effects of aldosterone because the MR receptor is found in multiple tissues, and TRPM7 and SGK1 are ubiquitously expressed. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Gonadotropin-Releasing Hormone Stimulate Aldosterone Production in a Subset of Aldosterone-Producing Adenoma

    PubMed Central

    Kishimoto, Rui; Oki, Kenji; Yoneda, Masayasu; Gomez-Sanchez, Celso E.; Ohno, Haruya; Kobuke, Kazuhiro; Itcho, Kiyotaka; Kohno, Nobuoki

    2016-01-01

    Abstract We aimed to detect novel genes associated with G protein-coupled receptors (GPCRs) in aldosterone-producing adenoma (APA) and elucidate the mechanisms underlying aldosterone production. Microarray analysis targeting GPCR-associated genes was conducted using APA without known mutations (APA-WT) samples (n = 3) and APA with the KCNJ5 mutation (APA-KCNJ5; n = 3). Since gonadotropin-releasing hormone receptor (GNRHR) was the highest expression in APA-WT by microarray analysis, we investigated the effect of gonadotropin-releasing hormone (GnRH) stimulation on aldosterone production. The quantitative polymerase chain reaction assay results revealed higher GNRHR expression levels in APA-WT samples those in APA-KCNJ5 samples (P < 0.05). LHCGR levels were also significantly elevated in APA-WT samples, and there was a significant and positive correlation between GNRHR and LHCGR expression in all APA samples (r = 0.476, P < 0.05). Patients with APA-WT (n = 9), which showed higher GNRHR and LHCGR levels, had significantly higher GnRH-stimulated aldosterone response than those with APA-KCNJ5 (n = 13) (P < 0.05). Multiple regression analysis revealed that the presence of the KCNJ5 mutation was linked to GNRHR mRNA expression (β = 0.94 and P < 0.01). HAC15 cells with KCNJ5 gene carrying T158A mutation exhibited a significantly lower GNRHR expression than that in control cells (P < 0.05). We clarified increased expression of GNRHR and LHCGR in APA-WT, and the molecular analysis including the receptor expression associated with clinical findings of GnRH stimulation. PMID:27196470

  11. Prenatal Testosterone Exposure Decreases Aldosterone Production but Maintains Normal Plasma Volume and Increases Blood Pressure in Adult Female Rats.

    PubMed

    More, Amar S; Mishra, Jay S; Hankins, Gary D; Kumar, Sathish

    2016-08-01

    Plasma testosterone levels are elevated in pregnant women with preeclampsia and polycystic ovaries; their offspring are at increased risk for hypertension during adult life. We tested the hypothesis that prenatal testosterone exposure induces dysregulation of the renin-angiotensin-aldosterone system, which is known to play an important role in water and electrolyte balance and blood pressure regulation. Female rats (6 mo old) prenatally exposed to testosterone were examined for adrenal expression of steroidogenic genes, telemetric blood pressure, blood volume and Na(+) and K(+) levels, plasma aldosterone, angiotensin II and vasopressin levels, and vascular responses to angiotensin II and arg(8)-vasopressin. The levels of Cyp11b2 (aldosterone synthase), but not the other adrenal steroidogenic genes, were decreased in testosterone females. Accordingly, plasma aldosterone levels were lower in testosterone females. Plasma volume and serum and urine Na(+) and K(+) levels were not significantly different between control and testosterone females; however, prenatal testosterone exposure significantly increased plasma vasopressin and angiotensin II levels and arterial pressure in adult females. In testosterone females, mesenteric artery contractile responses to angiotensin II were significantly greater, while contractile responses to vasopressin were unaffected. Angiotensin II type-1 receptor expression was increased, while angiotensin II type-2 receptor was decreased in testosterone arteries. These results suggest that prenatal testosterone exposure downregulates adrenal Cyp11b2 expression, leading to decreased plasma aldosterone levels. Elevated angiotensin II and vasopressin levels along with enhanced vascular responsiveness to angiotensin II may serve as an underlying mechanism to maintain plasma volume and Na(+) and K(+) levels and mediate hypertension in adult testosterone females. © 2016 by the Society for the Study of Reproduction, Inc.

  12. High risk of adrenal toxicity of N1-desoxy quinoxaline 1,4-dioxide derivatives and the protection of oligomeric proanthocyanidins (OPC) in the inhibition of the expression of aldosterone synthetase in H295R cells.

    PubMed

    Wang, Xu; Yang, Chunhui; Ihsan, Awais; Luo, Xun; Guo, Pu; Cheng, Guyue; Dai, Menghong; Chen, Dongmei; Liu, Zhenli; Yuan, Zonghui

    2016-02-03

    Quinoxaline 1,4-dioxide derivatives (QdNOs) with a wide range of biological activities are used in animal husbandry worldwide. It was found that QdNOs significantly inhibited the gene expression of CYP11B1 and CYP11B2, the key aldosterone synthases, and thus reduced aldosterone levels. However, whether the metabolites of QdNOs have potential adrenal toxicity and the role of oxidative stress in the adrenal toxicity of QdNOs remains unclear. The relatively new QdNOs, cyadox (CYA), mequindox (MEQ), quinocetone (QCT) and their metabolites, were selected for elucidation of their toxic mechanisms in H295R cells. Interestingly, the results showed that the main toxic metabolites of QCT, MEQ, and CYA were their N1-desoxy metabolites, which were more harmful than other metabolites and evoked dose and time-dependent cell damage on adrenal cells and inhibited aldosterone production. Gene and protein expression of CYP11B1 and CYP11B2 and mRNA expression of transcription factors, such as NURR1, NGFIB, CREB, SF-1, and ATF-1, were down regulated by N1-desoxy QdNOs. The natural inhibitors of oxidant stress, oligomeric proanthocyanidins (OPC), could upregulate the expression of diverse transcription factors, including CYP11B1 and CYP11B2, and elevated aldosterone levels to reduce adrenal toxicity. This study demonstrated for the first time that N1-desoxy QdNOs have the potential to be the major toxic metabolites in adrenal toxicity, which may shed new light on the adrenal toxicity of these fascinating compounds and help to provide a basic foundation for the formulation of safety controls for animal products and the design of new QdNOs with less harmful effects. Copyright © 2016. Published by Elsevier Ireland Ltd.

  13. SFE/SFHTA/AFCE consensus on primary aldosteronism, part 5: Genetic diagnosis of primary aldosteronism.

    PubMed

    Zennaro, Maria-Christina; Jeunemaitre, Xavier

    2016-07-01

    While the majority of cases of primary aldosteronism (PA) are sporadic, four forms of autosomal-dominant inheritance have been described: familial hyperaldosteronism (FH) types I to IV. FH-I, also called glucocorticoid-remediable aldosteronism, is characterized by early and severe hypertension, usually before the age of 20 years. It is due to the formation of a chimeric gene between the adjacent CYP11B2 and CYP11B1 genes (coding for aldosterone synthase and 11β-hydroxylase, respectively). FH-I is often associated with family history of stroke before 40years of age. FH-II is clinically and biochemically indistinguishable from sporadic forms of PA and is only diagnosed on the basis of two or more affected family members. No causal genes have been identified so far and no genetic test is available. FH-III is characterized by severe and early-onset hypertension in children and young adults, resistant to treatment and associated with severe hypokalemia. Mild forms, resembling FH-II, have been described. FH-III is due to gain-of-function mutations in the KCNJ5 gene. Recently, a new autosomal-dominant form of familial PA, FH-IV, associated with mutations in the CACNA1H gene, was described in patients with hypertension and PA before the age of 10years. In rare cases, PA may be associated with complex neurologic disorder involving epileptic seizures and cerebral palsy (Primary Aldosteronism, Seizures, and Neurologic Abnormalities [PASNA]) due to de novo germline CACNA1D mutations. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  14. Regulators of G-protein signaling 4 in adrenal gland: localization, regulation, and role in aldosterone secretion.

    PubMed

    Romero, Damian G; Zhou, Ming Yi; Yanes, Licy L; Plonczynski, Maria W; Washington, Tanganika R; Gomez-Sanchez, Celso E; Gomez-Sanchez, Elise P

    2007-08-01

    Regulators of G-protein signaling (RGS proteins) interact with Galpha subunits of heterotrimeric G-proteins, accelerating the rate of GTP hydrolysis and finalizing the intracellular signaling triggered by the G-protein-coupled receptor (GPCR)-ligand interaction. Angiotensin II (Ang II) interacts with its GPCR in adrenal zona glomerulosa cells and triggers a cascade of intracellular signals that regulates steroidogenesis and proliferation. On screening for adrenal zona glomerulosa-specific genes, we found that RGS4 was exclusively localized in the zona glomerulosa of the rat adrenal cortex. We studied RGS4 expression and regulation in the rat adrenal gland, including the signaling pathways involved, as well as the role of RGS4 in steroidogenesis in human adrenocortical H295R cells. We reported that RGS4 mRNA expression in the rat adrenal gland was restricted to the adrenal zonal glomerulosa and upregulated by low-salt diet and Ang II infusion in rat adrenal glands in vivo. In H295R cells, Ang II caused a rapid and transient increase in RGS4 mRNA levels mediated by the calcium/calmodulin/calmodulin-dependent protein kinase and protein kinase C pathways. RGS4 overexpression by retroviral infection in H295R cells decreased Ang II-stimulated aldosterone secretion. In reporter assays, RGS4 decreased Ang II-mediated aldosterone synthase upregulation. In summary, RGS4 is an adrenal gland zona glomerulosa-specific gene that is upregulated by aldosterone secretagogues, in vivo and in vitro, and functions as a negative feedback of Ang II-triggered intracellular signaling. Alterations in RGS4 expression levels or functions may be involved in deregulations of Ang II signaling and abnormal aldosterone secretion.

  15. Aldosterone stimulates superoxide production in macula densa cells.

    PubMed

    Zhu, Xiaolong; Manning, R Davis; Lu, Deyin; Gomez-Sanchez, Celso E; Fu, Yiling; Juncos, Luis A; Liu, Ruisheng

    2011-09-01

    Two major factors which regulate tubuloglomerular feedback (TGF)-mediated constriction of the afferent arteriole are release of superoxide (O(2)(-)) and nitric oxide (NO) by macula densa (MD) cells. MD O(2)(-) inactivates NO; however, among the factors that increase MD O(2)(-) release, the role of aldosterone is unclear. We hypothesize that aldosterone activates the mineralocorticoid receptor (MR) on MD cells, resulting in increased O(2)(-) production due to upregulation of cyclooxygenase-1 (COX-2) and NOX-2, and NOX-4, isoforms of NAD(P)H oxidase. Studies were performed on MMDD1 cells, a renal epithelial cell line with properties of MD cells. RT-PCR and Western blotting confirmed the expression of MR. Aldosterone (10(-8) mol/l for 30 min) doubled MMDD1 cell O(2)(-) production, and this was completely blocked by MR inhibition with 10(-5) mol/l eplerenone. RT-PCR, real-time PCR, and Western blotting demonstrated aldosterone-induced increases in COX-2, NOX-2, and NOX-4 expression. Inhibition of COX-2 (NS398), NADPH oxidase (apocynin), or a combination blocked aldosterone-induced O(2)(-) production to the same degree. These data suggest that aldosterone-stimulated MD O(2)(-) production is mediated by COX-2 and NADPH oxidase. Next, COX-2 small-interfering RNA (siRNA) specifically decreased COX-2 mRNA without affecting NOX-2 or NOX-4 mRNAs. In the presence of the COX-2 siRNA, the aldosterone-induced increases in COX-2, NOX-2, and NOX-4 mRNAs and O(2)(-) production were completely blocked, suggesting that COX-2 causes increased expression of NOX-2 and NOX-4. In conclusion 1) MD cells express MR; 2) aldosterone increases O(2)(-) production by activating MR; and 3) aldosterone stimulates COX-2, which further activates NOX-2 and NOX-4 and generates O(2)(-). The resulting balance between O(2)(-) and NO in the MD is important in modulating TGF.

  16. Purkinje Cell Protein 4 Expression Is Associated With DNA Methylation Status in Aldosterone-Producing Adenoma.

    PubMed

    Kobuke, Kazuhiro; Oki, Kenji; Gomez-Sanchez, Celso E; Ohno, Haruya; Itcho, Kiyotaka; Yoshii, Yoko; Yoneda, Masayasu; Hattori, Noboru

    2018-03-01

    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. 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. 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. 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. 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.

  17. Effect of aldosterone on BK channel expression in mammalian cortical collecting duct

    PubMed Central

    Estilo, Genevieve; Liu, Wen; Pastor-Soler, Nuria; Mitchell, Phillip; Carattino, Marcelo D.; Kleyman, Thomas R.; Satlin, Lisa M.

    2008-01-01

    Apical large-conductance Ca2+-activated K+ (BK) channels in the cortical collecting duct (CCD) mediate flow-stimulated K+ secretion. Dietary K+ loading for 10–14 days leads to an increase in BK channel mRNA abundance, enhanced flow-stimulated K+ secretion in microperfused CCDs, and a redistribution of immunodetectable channels from an intracellular pool to the apical membrane (Najjar F, Zhou H, Morimoto T, Bruns JB, Li HS, Liu W, Kleyman TR, Satlin LM. Am J Physiol Renal Physiol 289: F922–F932, 2005). To test whether this adaptation was mediated by a K+-induced increase in aldosterone, New Zealand White rabbits were fed a low-Na+ (LS) or high-Na+ (HS) diet for 7–10 days to alter circulating levels of aldosterone but not serum K+ concentration. Single CCDs were isolated for quantitation of BK channel subunit (total, α-splice variants, β-isoforms) mRNA abundance by real-time PCR and measurement of net transepithelial Na+ (JNa) and K+ (JK) transport by microperfusion; kidneys were processed for immunolocalization of BK α-subunit by immunofluorescence microscopy. At the time of death, LS rabbits excreted no urinary Na+ and had higher circulating levels of aldosterone than HS animals. The relative abundance of BK α-, β2-, and β4-subunit mRNA and localization of immunodetectable α-subunit were similar in CCDs from LS and HS animals. In response to an increase in tubular flow rate from ∼1 to 5 nl·min−1·mm−1, the increase in JNa was greater in LS vs. HS rabbits, yet the flow-stimulated increase in JK was similar in both groups. These data suggest that aldosterone does not contribute to the regulation of BK channel expression/activity in response to dietary K+ loading. PMID:18579708

  18. Aldosterone acutely stimulates NCC activity via a SPAK-mediated pathway.

    PubMed

    Ko, Benjamin; Mistry, Abinash C; Hanson, Lauren; Mallick, Rickta; Wynne, Brandi M; Thai, Tiffany L; Bailey, James L; Klein, Janet D; Hoover, Robert S

    2013-09-01

    Hypertension is a leading cause of morbidity and mortality worldwide, and disordered sodium balance has long been implicated in its pathogenesis. Aldosterone is perhaps the key regulator of sodium balance and thus blood pressure. The sodium chloride cotransporter (NCC) in the distal convoluted tubule of the kidney is a major site of sodium reabsorption and plays a key role in blood pressure regulation. Chronic exposure to aldosterone increases NCC protein expression and function. However, more acute effects of aldosterone on NCC are unknown. In our salt-abundant modern society where chronic salt deprivation is rare, understanding the acute effects of aldosterone is critical. Here, we examined the acute effects (12-36 h) of aldosterone on NCC in the rodent kidney and in a mouse distal convoluted tubule cell line. Studies demonstrated that aldosterone acutely stimulated NCC activity and phosphorylation without affecting total NCC abundance or surface expression. This effect was dependent upon the presence of the mineralocorticoid receptor and serum- and glucocorticoid-regulated kinase 1 (SGK1). Furthermore, STE20/SPS-1-related proline/alanine-rich kinase (SPAK) phosphorylation also increased, and gene silencing of SPAK eliminated the effect of aldosterone on NCC activity. Aldosterone administration via a minipump in adrenalectomized rodents confirmed an increase in NCC phosphorylation without a change in NCC total protein. These data indicate that acute aldosterone-induced SPAK-dependent phosphorylation of NCC increases individual transporter activity.

  19. Aldosterone acutely stimulates NCC activity via a SPAK-mediated pathway

    PubMed Central

    Mistry, Abinash C.; Hanson, Lauren; Mallick, Rickta; Wynne, Brandi M.; Thai, Tiffany L.; Bailey, James L.; Klein, Janet D.; Hoover, Robert S.

    2013-01-01

    Hypertension is a leading cause of morbidity and mortality worldwide, and disordered sodium balance has long been implicated in its pathogenesis. Aldosterone is perhaps the key regulator of sodium balance and thus blood pressure. The sodium chloride cotransporter (NCC) in the distal convoluted tubule of the kidney is a major site of sodium reabsorption and plays a key role in blood pressure regulation. Chronic exposure to aldosterone increases NCC protein expression and function. However, more acute effects of aldosterone on NCC are unknown. In our salt-abundant modern society where chronic salt deprivation is rare, understanding the acute effects of aldosterone is critical. Here, we examined the acute effects (12–36 h) of aldosterone on NCC in the rodent kidney and in a mouse distal convoluted tubule cell line. Studies demonstrated that aldosterone acutely stimulated NCC activity and phosphorylation without affecting total NCC abundance or surface expression. This effect was dependent upon the presence of the mineralocorticoid receptor and serum- and glucocorticoid-regulated kinase 1 (SGK1). Furthermore, STE20/SPS-1-related proline/alanine-rich kinase (SPAK) phosphorylation also increased, and gene silencing of SPAK eliminated the effect of aldosterone on NCC activity. Aldosterone administration via a minipump in adrenalectomized rodents confirmed an increase in NCC phosphorylation without a change in NCC total protein. These data indicate that acute aldosterone-induced SPAK-dependent phosphorylation of NCC increases individual transporter activity. PMID:23739593

  20. Aldosterone and Mineralocorticoid Receptors-Physiology and Pathophysiology.

    PubMed

    Funder, John W

    2017-05-11

    Aldosterone is a uniquely terrestrial hormone, first appearing in lungfish, which have both gills and lungs. Mineralocorticoid receptors (MRs), on the other hand, evolved much earlier, and are found in cartilaginous and bony fish, presumptive ligand cortisol. MRs have equivalent high affinity for aldosterone, progesterone, and cortisol; in epithelia, despite much higher cortisol circulating levels, aldosterone selectively activates MRs by co-expression of the enzyme 11β-hydroxysteroid dehydrogenase, Type 11. In tissues in which the enzyme is not expressed, MRs are overwhelmingly occupied but not activated by cortisol, which normally thus acts as an MR antagonist; in tissue damage, however, cortisol mimics aldosterone and acts as an MR agonist. The risk profile for primary aldosteronism (PA) is much higher than that in age-, sex-, and blood pressure-matched essential hypertensives. High levels of aldosterone per se are not the problem: in chronic sodium deficiency, as seen in the monsoon season in the highlands of New Guinea, plasma aldosterone levels are extraordinarily high, but cause neither hypertension nor cardiovascular damage. Such damage occurs when aldosterone levels are out of the normal feedback control, and are inappropriately elevated for the salt status of the individual (or experimental animal). The question thus remains of how excess salt can synergize with elevated aldosterone levels to produce deleterious cardiovascular effects. One possible mechanism is through the agency of the elusive ouabain-like factors (OLFs). Such factors are secreted from the adrenal in response to ACTH (adrenalocortical tropic hormone), to angiotensin via AT2R, and-the polar opposite of aldosterone-to sodium loading. They act on blood vessels to cause vasoconstriction and thus elevate blood pressure to dump excess sodium through pressure natriuresis. Their levels are chronically elevated in PA in response to the continually elevated sodium status, and they thus act to

  1. Local Control of Aldosterone Production and Primary Aldosteronism.

    PubMed

    Lalli, Enzo; Barhanin, Jacques; Zennaro, Maria-Christina; Warth, Richard

    2016-03-01

    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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Fenofibrate inhibits aldosterone-induced apoptosis in adult rat ventricular myocytes via stress-activated kinase-dependent mechanisms

    PubMed Central

    De Silva, Deepa S.; Wilson, Richard M.; Hutchinson, Christoph; Ip, Peter C.; Garcia, Anthony G.; Lancel, Steve; Ito, Masa; Pimentel, David R.; Sam, Flora

    2009-01-01

    Aldosterone induces extracellular signal-regulated kinase (ERK)-dependent cardiac remodeling. Fenofibrate improves cardiac remodeling in adult rat ventricular myocytes (ARVM) partly via inhibition of aldosterone-induced ERK1/2 phosphorylation and inhibition of matrix metalloproteinases. We sought to determine whether aldosterone caused apoptosis in cultured ARVM and whether fenofibrate ameliorated the apoptosis. Aldosterone (1 μM) induced apoptosis by increasing terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL)-positive nuclei in ARVM. Spironolactone (100 nM), an aldosterone receptor antagonist, but not RU-486, a glucocorticoid receptor, inhibited aldosterone-mediated apoptosis, indicating that the mineralocorticoid receptor (MR) plays a role. SP-600125 (3 μM)—a selective inhibitor of c-Jun NH2-terminal kinase (JNK)—inhibited aldosterone-induced apoptosis in ARVM. Although aldosterone increased the expression of both stress-activated protein kinases, pretreatment with fenofibrate (10 μM) decreased aldosterone-mediated apoptosis by inhibiting only JNK phosphorylation and the aldosterone-induced increases in Bax, p53, and cleaved caspase-3 and decreases in Bcl-2 protein expression in ARVM. In vivo studies demonstrated that chronic fenofibrate (100 mg·kg body wt−1·day−1) inhibited myocardial Bax and increased Bcl-2 expression in aldosterone-induced cardiac hypertrophy. Similarly, eplerenone, a selective MR inhibitor, used in chronic pressure-overload ascending aortic constriction inhibited myocardial Bax expression but had no effect on Bcl-2 expression. Therefore, involvement of JNK MAPK-dependent mitochondrial death pathway mediates ARVM aldosterone-induced apoptosis and is inhibited by fenofibrate, a peroxisome proliferator-activated receptor (PPAR)α ligand. Fenofibrate mediates beneficial effects in cardiac remodeling by inhibiting programmed cell death and the stress-activated kinases. PMID:19395558

  3. Therapeutic targeting of aldosterone: a novel approach to the treatment of glomerular disease

    PubMed Central

    Brem, Andrew S.; Gong, Rujun

    2015-01-01

    Numerous studies have established a role for mineralocorticoids in the development of renal fibrosis. Originally, the research focus for mineralocorticoid-induced fibrosis was on the collecting duct, where “classical” mineralocorticoid receptors (MR) involved with electrolyte transport are present. Epithelial cells in this segment can, under selected circumstances, also respond to MR activation by initiating pro-fibrotic pathways. More recently, “non-classical” MR have been described in kidney cells not associated with electrolyte transport including mesangial cells and podocytes within the glomerulus. Activation of MR in these cells appears to lead to glomerular sclerosis. Mechanistically, aldosterone induces excess production of reactive oxygen species (ROS) and oxidative stress in glomerular cells through activation of NADPH oxidase. In mesangial cells, aldosterone also has pro-apoptotic, mitogenic, and pro-fibrogenic effects, all of which potentially promote active remodeling and expansion of the mesangium. While mitochondrial dysfunction seems to mediate the aldosterone-induced mesangial apoptosis, the ROS dependent EGFR transactivation is likely responsible for aldosterone-induced mesangial mitosis and proliferation. In podocytes, mitochondrial dysfunction elicited by oxidative stress is an early event associated with aldosterone-induced podocyte injury. Both the p38MAPK signaling and the redox sensitive glycogen synthase kinase (GSK) 3β pathways are centrally implicated in aldosterone-induced podocyte death. Aldosterone-induced GSK3β over-activity could potentially cause hyperphosphorylation and over-activation of putative GSK3β substrates, including structural components of the mitochondrial permeability transition (MPT) pore, all of which lead to cell injury and death. Clinically, proteinuria significantly decreases when aldosterone inhibitors are included in the treatment of many glomerular diseases further supporting the view that

  4. Interleukin-33/ST2 system attenuates aldosterone-induced adipogenesis and inflammation.

    PubMed

    Martínez-Martínez, Ernesto; Cachofeiro, Victoria; Rousseau, Elodie; Álvarez, Virginia; Calvier, Laurent; Fernández-Celis, Amaya; Leroy, Céline; Miana, María; Jurado-López, Raquel; Briones, Ana M; Jaisser, Frederic; Zannad, Faiez; Rossignol, Patrick; López-Andrés, Natalia

    2015-08-15

    Interleukin-33 (IL-33) but not soluble ST2 (sST2) exerts anti-inflammatory and protective effects in several tissues. Aldosterone, a proinflammatory mediator which promotes adipogenesis, is elevated in obese patients. The aim of this study was to investigate the interactions between IL-33/ST2 system and Aldosterone in adipose tissue. Rats fed a high fat diet presented increased sST2 expression, diminished IL-33/sST2 ratio and enhanced levels of differentiation and inflammation in adipose tissue as compared to controls. A similar pattern was observed in adipose tissue from C57BL/6 Aldosterone-treated mice. In both animal models, Aldosterone was correlated with sST2. Treatment of 3T3-L1 adipocytes with IL-33 delayed adipocyte differentiation diminished lipid accumulation and decreased inflammation. Aldosterone decreased IL-33 and increased sST2 expressions in differentiated adipocytes. Aldosterone-induced adipocyte differentiation and inflammation were blocked by IL-33 treatment, but sST2 did not exert any effects. The crosstalk between IL-33/ST2 and Aldosterone could be relevant in the metabolic consequences of obesity. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. Aldosterone induces a vascular inflammatory phenotype in the rat heart.

    PubMed

    Rocha, Ricardo; Rudolph, Amy E; Frierdich, Gregory E; Nachowiak, Denise A; Kekec, Beverly K; Blomme, Eric A G; McMahon, Ellen G; Delyani, John A

    2002-11-01

    Vascular inflammation was examined as a potential mechanism of aldosterone-mediated myocardial injury in uninephrectomized rats receiving 1% NaCl-0.3% KCl to drink for 1, 2, or 4 wk and 1) vehicle, 2) aldosterone infusion (0.75 microg/h), or 3) aldosterone infusion (0.75 microg/h) plus the selective aldosterone blocker eplerenone (100 mg. kg(-1). day(-1)). Aldosterone induced severe hypertension at 4 wk [systolic blood pressure (SBP), 210 +/- 3 mmHg vs. vehicle, 131 +/- 2 mmHg, P < 0.001], which was partially attenuated by eplerenone (SBP, 180 +/- 7 mmHg; P < 0.001 vs. aldosterone alone and vehicle). No significant increases in myocardial interstitial collagen fraction or hydroxyproline concentration were detected throughout the study. However, histopathological analysis of the heart revealed severe coronary inflammatory lesions, which were characterized by monocyte/macrophage infiltration and resulted in focal ischemic and necrotic changes. The histological evidence of coronary lesions was preceded by and associated with the elevation of cyclooxygenase-2 (up to approximately 4-fold), macrophage chemoattractant protein-1 (up to approximately 4-fold), and osteopontin (up to approximately 13-fold) mRNA expression. Eplerenone attenuated proinflammatory molecule expression in the rat heart and subsequent vascular and myocardial damage. Thus aldosterone and salt treatment in uninephrectomized rats led to severe hypertension and the development of a vascular inflammatory phenotype in the heart, which may represent one mechanism by which aldosterone contributes to myocardial disease.

  6. Inflammation and Fibrosis in Perirenal Adipose Tissue of Patients With Aldosterone-Producing Adenoma.

    PubMed

    Wu, Chunyan; Zhang, Huijian; Zhang, Jiajun; Xie, Cuihua; Fan, Cunxia; Zhang, Hongbin; Wu, Peng; Wei, Qiang; Tan, Wanlong; Xu, Lingling; Wang, Ling; Xue, Yaoming; Guan, Meiping

    2018-01-01

    The prevalence of primary aldosteronism is much higher than previously thought. Recent studies have shown that primary aldosteronism is related to a higher risk of cardiovascular events. However, the underlying mechanism is not yet clear. Here we investigate the characteristics, including inflammation, fibrosis, and adipokine expression, of adipose tissues from different deposits in patients with aldosterone-producing adenoma (APA). Inflammation and fibrosis changes were evaluated in perirenal and subcutaneous adipose tissues obtained from patients with APA (n = 16), normotension (NT; n = 10), and essential hypertension (EH; n = 5) undergoing laparoscopic surgery. We also evaluated the effect of aldosterone in isolated human perirenal adipose tissue stromal vascular fraction (SVF) cells and investigated the effect of aldosterone in mouse 3T3-L1 and brown preadipocytes. Compared with the EH group, significantly higher levels of interleukin-6 (IL-6) and tumor necrosis factor-α messenger RNA (mRNA) and protein were observed in perirenal adipose tissue of patients with APA. Expression of genes related to fibrosis and adipogenesis in perirenal adipose tissue was notably higher in patients with APA than in patients with NT and EH. Aldosterone significantly induced IL-6 and fibrosis gene mRNA expression in differentiated SVF cells. Aldosterone treatment enhanced mRNA expression of genes associated with inflammation and fibrosis and stimulated differentiation of 3T3-L1 and brown preadipocytes. In conclusion, these data indicate that high aldosterone in patients with APA may induce perirenal adipose tissue dysfunction and lead to inflammation and fibrosis, which may be involved in the high risk of cardiovascular events observed in patients with primary aldosteronism. Copyright © 2018 Endocrine Society.

  7. Molecular cloning and functional expression of geranylgeranyl pyrophosphate synthase from Coleus forskohlii Briq

    PubMed Central

    Engprasert, Surang; Taura, Futoshi; Kawamukai, Makoto; Shoyama, Yukihiro

    2004-01-01

    Background Isopentenyl diphosphate (IPP), a common biosynthetic precursor to the labdane diterpene forskolin, has been biosynthesised via a non-mevalonate pathway. Geranylgeranyl diphosphate (GGPP) synthase is an important branch point enzyme in terpenoid biosynthesis. Therefore, GGPP synthase is thought to be a key enzyme in biosynthesis of forskolin. Herein we report the first confirmation of the GGPP synthase gene in Coleus forskohlii Briq. Results The open reading frame for full-length GGPP synthase encodes a protein of 359 amino acids, in which 1,077 nucleotides long with calculated molecular mass of 39.3 kDa. Alignments of C. forskohlii GGPP synthase amino acid sequences revealed high homologies with other plant GGPP synthases. Several highly conserved regions, including two aspartate-rich motifs were identified. Transient expression of the N-terminal region of C. forskohlii GGPP synthase-GFP fusion protein in tobacco cells demonstrated subcellular localization in the chloroplast. Carotenoid production was observed in Escherichia coli harboring pACCAR25ΔcrtE from Erwinia uredovora and plasmid carrying C. forskohlii GGPP synthase. These results suggested that cDNA encoded functional GGPP synthase. Furthermore, C. forskohlii GGPP synthase expression was strong in leaves, decreased in stems and very little expression was observed in roots. Conclusion This investigation proposed that forskolin was synthesised via a non-mevalonate pathway. GGPP synthase is thought to be involved in the biosynthesis of forskolin, which is primarily synthesised in the leaves and subsequently accumulates in the stems and roots. PMID:15550168

  8. NLRP3 Inflammasome Mediates Aldosterone-Induced Vascular Damage.

    PubMed

    Bruder-Nascimento, Thiago; Ferreira, Nathanne S; Zanotto, Camila Z; Ramalho, Fernanda; Pequeno, Isabela O; Olivon, Vania C; Neves, Karla B; Alves-Lopes, Rheure; Campos, Eduardo; Silva, Carlos Alberto A; Fazan, Rubens; Carlos, Daniela; Mestriner, Fabiola L; Prado, Douglas; Pereira, Felipe V; Braga, Tarcio; Luiz, Joao Paulo M; Cau, Stefany B; Elias, Paula C; Moreira, Ayrton C; Câmara, Niels O; Zamboni, Dario S; Alves-Filho, Jose Carlos; Tostes, Rita C

    2016-12-06

    Inflammation is a key feature of aldosterone-induced vascular damage and dysfunction, but molecular mechanisms by which aldosterone triggers inflammation remain unclear. The NLRP3 inflammasome is a pivotal immune sensor that recognizes endogenous danger signals triggering sterile inflammation. We analyzed vascular function and inflammatory profile of wild-type (WT), NLRP3 knockout (NLRP3 -/- ), caspase-1 knockout (Casp-1 -/- ), and interleukin-1 receptor knockout (IL-1R -/- ) mice treated with vehicle or aldosterone (600 µg·kg -1 ·d -1 for 14 days through osmotic mini-pump) while receiving 1% saline to drink. Here, we show that NLRP3 inflammasome plays a central role in aldosterone-induced vascular dysfunction. Long-term infusion of aldosterone in mice resulted in elevation of plasma interleukin-1β levels and vascular abnormalities. Mice lacking the IL-1R or the inflammasome components NLRP3 and caspase-1 were protected from aldosterone-induced vascular damage. In vitro, aldosterone stimulated NLRP3-dependent interleukin-1β secretion by bone marrow-derived macrophages by activating nuclear factor-κB signaling and reactive oxygen species generation. Moreover, chimeric mice reconstituted with NLRP3-deficient hematopoietic cells showed that NLRP3 in immune cells mediates aldosterone-induced vascular damage. In addition, aldosterone increased the expression of NLRP3, active caspase-1, and mature interleukin-1β in human peripheral blood mononuclear cells. Hypertensive patients with hyperaldosteronism or normal levels of aldosterone exhibited increased activity of NLRP3 inflammasome, suggesting that the effect of hyperaldosteronism on the inflammasome may be mediated through high blood pressure. Together, these data demonstrate that NLRP3 inflammasome, through activation of IL-1R, is critically involved in the deleterious vascular effects of aldosterone, placing NLRP3 as a potential target for therapeutic interventions in conditions with high aldosterone levels.

  9. Interleukin-18 deficiency protects against renal interstitial fibrosis in aldosterone/salt-treated mice.

    PubMed

    Tanino, Akiko; Okura, Takafumi; Nagao, Tomoaki; Kukida, Masayoshi; Pei, Zuowei; Enomoto, Daijiro; Miyoshi, Ken-Ichi; Okamura, Haruki; Higaki, Jitsuo

    2016-10-01

    Interleukin (IL)-18 is a member of the IL-1 family of cytokines and was described originally as an interferon γ-inducing factor. Aldosterone plays a central role in the regulation of sodium and potassium homoeostasis by binding to the mineralocorticoid receptor and contributes to kidney and cardiovascular damage. Aldosterone has been reported to induce IL-18, resulting in cardiac fibrosis with induced IL-18-mediated osteopontin (OPN). We therefore hypothesized that aldosterone-induced renal fibrosis via OPN may be mediated by IL-18. To verify this hypothesis, we compared mice deficient in IL-18 and wild-type (WT) mice in a model of aldosterone/salt-induced hypertension. IL-18(-/-) and C57BL/6 WT mice were used for the uninephrectomized aldosterone/salt hypertensive model, whereas NRK-52E cells (rat kidney epithelial cells) were used in an in vitro model. In the present in vivo study, IL-18 protein expression was localized in medullary tubules in the WT mice, whereas in aldosterone-infused WT mice this expression was up-regulated markedly in the proximal tubules, especially in injured and dilated tubules. This renal damage caused by aldosterone was attenuated significantly by IL-18 knockout with down-regulation of OPN expression. In the present in vitro study, aldosterone directly induced IL-18 gene expression in renal tubular epithelial cells in a concentration- and time-dependent manner. These effects were inhibited completely by spironolactone. IL-18 may be a key mediator of aldosterone-induced renal fibrosis by inducing OPN, thereby exacerbating renal interstitial fibrosis. Inhibition of IL-18 may therefore provide a potential target for therapeutic intervention aimed at preventing the progression of renal injury. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

  10. Distal Renal Tubules Are Deficient in Aggresome Formation and Autophagy upon Aldosterone Administration

    PubMed Central

    Cheema, Muhammad Umar; Damkier, Helle Hasager; Nielsen, Jakob; Poulsen, Ebbe Toftgaard; Enghild, Jan J.; Fenton, Robert A.; Praetorius, Jeppe

    2014-01-01

    Prolonged elevations of plasma aldosterone levels are associated with renal pathogenesis. We hypothesized that renal distress could be imposed by an augmented aldosterone-induced protein turnover challenging cellular protein degradation systems of the renal tubular cells. Cellular accumulation of specific protein aggregates in rat kidneys was assessed after 7 days of aldosterone administration. Aldosterone induced intracellular accumulation of 60 s ribosomal protein L22 in protein aggregates, specifically in the distal convoluted tubules. The mineralocorticoid receptor inhibitor spironolactone abolished aldosterone-induced accumulation of these aggregates. The aldosterone-induced protein aggregates also contained proteasome 20 s subunits. The partial de-ubiquitinase ataxin-3 was not localized to the distal renal tubule protein aggregates, and the aggregates only modestly colocalized with aggresome transfer proteins dynactin p62 and histone deacetylase 6. Intracellular protein aggregation in distal renal tubules did not lead to development of classical juxta-nuclear aggresomes or to autophagosome formation. Finally, aldosterone treatment induced foci in renal cortex of epithelial vimentin expression and a loss of E-cadherin expression, as signs of cellular stress. The cellular changes occurred within high, but physiological aldosterone concentrations. We conclude that aldosterone induces protein accumulation in distal renal tubules; these aggregates are not cleared by autophagy that may lead to early renal tubular damage. PMID:25000288

  11. Aldosterone mediates its rapid effects in vascular endothelial cells through GPER activation.

    PubMed

    Gros, Robert; Ding, Qingming; Liu, Bonan; Chorazyczewski, Jozef; Feldman, Ross D

    2013-03-01

    The importance of the rapid vascular effects of aldosterone is increasingly appreciated. Through these rapid pathways, aldosterone has been shown to regulate vascular contractility, cell growth, and apoptosis. In our most recent studies, we demonstrated the effects of aldosterone on cell growth and contractility in vascular smooth muscle cells. We showed that these effects could occur via activation of the classic mineralocorticoid receptor, as well the recently characterized G protein-coupled estrogen receptor (GPER), initially characterized as an estrogen-specific receptor. However, the mechanisms underlying aldosterone's endothelium-dependent actions are unknown. Furthermore, the ERK regulatory and proapoptotic effects of aldosterone mediated by GPER activation in cultured vascular smooth muscle cells were only apparent when GPER was reintroduced into these cells by gene transfer. Whether GPER activation via aldosterone might be an important regulator in native vascular cells has been questioned. Therefore, to determine the role of GPER in mediating aldosterone's effects on cell growth and vascular reactivity in native cells, we examined rat aortic vascular endothelial cells, a model characterized by persistent robust expression of GPER, but without detectable mineralocorticoid receptor expression. In these endothelial cells, the GPER agonist G1 mediates a rapid increase in ERK phosphorylation that is wholly GPER-dependent, paralleling the actions of aldosterone. The effects of G1 and aldosterone to stimulate ERK phosphorylation paralleled their proapoptotic and antiproliferative effects. In previous studies, we reported that aldosterone mediates a rapid endothelium-dependent vasodilatory effect, antagonistic to its direct vasoconstrictor effect in endothelium-denuded preparations. Using a rat aortic ring/organ bath preparation to determine the GPER dependence of aldosterone's endothelium-dependent vasodilator effects, we demonstrate that aldosterone inhibits

  12. Aldosterone sensitizes connecting tubule glomerular feedback via the aldosterone receptor GPR30

    PubMed Central

    Ren, YiLin; D'Ambrosio, Martin A.; Garvin, Jeffrey L.; Leung, Pablo; Kutskill, Kristopher; Wang, Hong; Peterson, Edward L.

    2014-01-01

    Increasing Na delivery to epithelial Na channels (ENaC) in the connecting tubule (CNT) dilates the afferent arteriole (Af-Art), a process we call connecting tubule glomerular feedback (CTGF). We hypothesize that aldosterone sensitizes CTGF via a nongenomic mechanism that stimulates CNT ENaC via the aldosterone receptor GPR30. Rabbit Af-Arts and their adherent CNTs were microdissected and simultaneously perfused. Two consecutive CTGF curves were elicited by increasing luminal NaCl in the CNT. During the control period, the concentration of NaCl that elicited a half-maximal response (EC50) was 37.0 ± 2.0 mmol/l; addition of aldosterone 10−8 mol/l to the CNT lumen caused a left-shift (decrease) in EC50 to 19.3 ± 1.3 mmol/l (P = 0.001 vs. control; n = 6). Neither the transcription inhibitor actinomycin D nor the translation inhibitor cycloheximide prevented the effect of aldosterone (control EC50 = 34.7 ± 1.9 mmol/l; aldosterone+actinomycin D EC50 = 22.6 ± 1.6 mmol/l; P < 0.001 and control EC50 = 32.4 ± 4.3 mmol/l; aldosterone+cycloheximide EC50 = 17.4 ± 3.3 mmol/l; P < 0.001). The aldosterone antagonist eplerenone prevented the sensitization of CTGF by aldosterone (control EC50 = 33.2 ± 1.7 mmol/l; aldosterone+eplerenone EC50 = 33.5 ± 1.3 mmol/l; n = 7). The GPR30 receptor blocker G-36 blocked the sensitization of CTGF by aldosterone (aldosterone EC50 = 16.5 ± 1.9 mmol/l; aldosterone+G-36 EC50 = 29.0 ± 2.1 mmol/l; n = 7; P < 0.001). Finally, we found that the sensitization of CTGF by aldosterone was mediated, at least in part, by the sodium/hydrogen exchanger (NHE). We conclude that aldosterone in the CNT lumen sensitizes CTGF via a nongenomic effect involving GPR30 receptors and NHE. Sensitized CTGF induced by aldosterone may contribute to renal damage by increasing Af-Art dilation and glomerular capillary pressure (glomerular barotrauma). PMID:24966088

  13. Aldosterone Induced Galectin-3 Secretion In Vitro and In Vivo: From Cells to Humans

    PubMed Central

    Lin, Yen-Hung; Chou, Chia-Hung; Wu, Xue-Ming; Chang, Yi-Yao; Hung, Chi-Sheng; Chen, Ying-Hsien; Tzeng, Yu-Lin; Wu, Vin-Cent; Ho, Yi-Lwun; Hsieh, Fon-Jou; Wu, Kwan-Dun

    2014-01-01

    Context Patients with primary aldosteronism are associated with increased myocardial fibrosis. Galectin-3 is one of the most important mediators between macrophage activation and myocardial fibrosis. Objective To investigate whether aldosterone induces galectin-3 secretion in vitro and in vivo. Methods and Results We investigated the possible molecular mechanism of aldosterone-induced galectin-3 secretion in macrophage cell lines (THP-1 and RAW 264.7 cells). Aldosterone induced galectin-3 secretion through mineralocorticoid receptors via the PI3K/Akt and NF-κB transcription signaling pathways. In addition, aldosterone-induced galectin-3 expression enhanced fibrosis-related factor expression in fibroblasts. We observed that galectin-3 mRNA from peripheral blood mononuclear cells and serum galectin-3 levels were both significantly increased in mice implanted with aldosterone pellets on days 7 and 14. We then conducted a prospective preliminary clinical study to investigate the association between aldosterone and galectin-3. Patients with aldosterone-producing adenoma had a significantly higher plasma galectin-3 level than patients with essential hypertension. One year after adrenalectomy, the plasma galectin-3 level had decreased significantly in the patients with aldosterone-producing adenoma. Conclusion This study demonstrated that aldosterone could induce galectin-3 secretion in vitro and in vivo. PMID:25180794

  14. Intra-adrenal Aldosterone Secretion: Segmental Adrenal Venous Sampling for Localization.

    PubMed

    Satani, Nozomi; Ota, Hideki; Seiji, Kazumasa; Morimoto, Ryo; Kudo, Masataka; Iwakura, Yoshitsugu; Ono, Yoshikiyo; Nezu, Masahiro; Omata, Kei; Ito, Sadayoshi; Satoh, Fumitoshi; Takase, Kei

    2016-01-01

    To use segmental adrenal venous sampling (AVS) (S-AVS) of effluent tributaries (a version of AVS that, in addition to helping identify aldosterone hypersecretion, also enables the evaluation of intra-adrenal hormone distribution) to detect and localize intra-adrenal aldosterone secretion. The institutional review board approved this study, and all patients provided informed consent. S-AVS was performed in 65 patients with primary aldosteronism (34 men; mean age, 50.9 years ± 11 [standard deviation]). A microcatheter was inserted in first-degree tributary veins. Unilateral aldosterone hypersecretion at the adrenal central vein was determined according to the lateralization index after cosyntropin stimulation. Excess aldosterone secretion at the adrenal tributary vein was considered to be present when the aldosterone/cortisol ratio from this vein exceeded that from the external iliac vein; suppressed secretion was indicated by the opposite pattern. Categoric variables were expressed as numbers and percentages; continuous variables were expressed as means ± standard errors of the mean. The AVS success rate, indicated by a selectivity index of 5 or greater, was 98% (64 of 65). The mean numbers of sampled tributaries on the left and right sides were 2.11 and 1.02, respectively. The following diagnoses were made on the basis of S-AVS results: unilateral aldosterone hypersecretion in 30 patients, bilateral hypersecretion without suppressed segments in 22 patients, and bilateral hypersecretion with at least one suppressed segment in 12 patients. None of the patients experienced severe complications. S-AVS could be used to identify heterogeneous intra-adrenal aldosterone secretion. Patients who have bilateral aldosterone-producing adenomas can be treated with adrenal-sparing surgery or other minimally invasive local therapies if any suppressed segment is identified at S-AVS. © RSNA, 2015.

  15. The impact of galectin-3 inhibition on aldosterone-induced cardiac and renal injuries.

    PubMed

    Calvier, Laurent; Martinez-Martinez, Ernesto; Miana, Maria; Cachofeiro, Victoria; Rousseau, Elodie; Sádaba, J Rafael; Zannad, Faiez; Rossignol, Patrick; López-Andrés, Natalia

    2015-01-01

    This study investigated whether galectin (Gal)-3 inhibition could block aldosterone-induced cardiac and renal fibrosis and improve cardiorenal dysfunction. Aldosterone is involved in cardiac and renal fibrosis that is associated with the development of cardiorenal injury. However, the mechanisms of these interactions remain unclear. Gal-3, a β-galactoside-binding lectin, is increased in heart failure and kidney injury. Rats were treated with aldosterone-salt combined with spironolactone (a mineralocorticoid receptor antagonist) or modified citrus pectin (a Gal-3 inhibitor), for 3 weeks. Wild-type and Gal-3 knockout mice were treated with aldosterone for 3 weeks. Hemodynamic, cardiac, and renal parameters were analyzed. Hypertensive aldosterone-salt-treated rats presented cardiac and renal hypertrophy (at morphometric, cellular, and molecular levels) and dysfunction. Cardiac and renal expressions of Gal-3 as well as levels of molecular markers attesting fibrosis were also augmented by aldosterone-salt treatment. Spironolactone or modified citrus pectin treatment reversed all of these effects. In wild-type mice, aldosterone did not alter blood pressure levels but increased cardiac and renal Gal-3 expression, fibrosis, and renal epithelial-mesenchymal transition. Gal-3 knockout mice were resistant to aldosterone effects. In experimental hyperaldosteronism, the increase in Gal-3 expression was associated with cardiac and renal fibrosis and dysfunction but was prevented by pharmacological inhibition (modified citrus pectin) or genetic disruption of Gal-3. These data suggest a key role for Gal-3 in cardiorenal remodeling and dysfunction induced by aldosterone. Gal-3 could be used as a new biotarget for specific pharmacological interventions. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  16. Of channels and pumps: different ways to boost the aldosterone?

    PubMed

    Bandulik, S

    2017-07-01

    The mineralocorticoid aldosterone is a major factor controlling the salt and water balance and thereby also the arterial blood pressure. Accordingly, primary aldosteronism (PA) characterized by an inappropriately high aldosterone secretion is the most common form of secondary hypertension. The physiological stimulation of aldosterone synthesis in adrenocortical glomerulosa cells by angiotensin II and an increased plasma K + concentration depends on a membrane depolarization and an increase in the cytosolic Ca 2+ activity. Recurrent gain-of-function mutations of ion channels and transporters have been identified in a majority of cases of aldosterone-producing adenomas and in familial forms of PA. In this review, the physiological role of these genes in the regulation of aldosterone synthesis and the altered function of the mutant proteins as well are described. The specific changes of the membrane potential and the cellular ion homoeostasis in adrenal cells expressing the different mutants are compared, and their impact on autonomous aldosterone production and proliferation is discussed. © 2016 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  17. Dysregulation of Aldosterone Secretion in Mast Cell-Deficient Mice.

    PubMed

    Boyer, Hadrien-Gaël; Wils, Julien; Renouf, Sylvie; Arabo, Arnaud; Duparc, Céline; Boutelet, Isabelle; Lefebvre, Hervé; Louiset, Estelle

    2017-12-01

    Resident adrenal mast cells have been shown to activate aldosterone secretion in rat and man. Especially, mast cell proliferation has been observed in adrenal tissues from patients with aldosterone-producing adrenocortical adenoma. In the present study, we show that the activity of adrenal mast cells is stimulated by low-sodium diet and correlates with aldosterone synthesis in C57BL/6 and BALB/c mice. We have also investigated the regulation of aldosterone secretion in mast cell-deficient C57BL/6 Kit W-sh/W-sh mice in comparison with wild-type C57BL/6 mice. Kit W-sh/W-sh mice submitted to normal sodium diet had basal plasma aldosterone levels similar to those observed in wild-type animals. Conversely, low-sodium diet unexpectedly induced an exaggerated aldosterone response, which seemed to result from an increase in adrenal renin and angiotensin type 1 receptor expression. Severe hyperaldosteronism was associated with an increase in systolic blood pressure and marked hypokalemia, which favored polyuria. Adrenal renin and angiotensin type 1 receptor overexpression may represent a compensatory mechanism aimed at activating aldosterone production in the absence of mast cells. Finally, C57BL/6 Kit W-sh/W-sh mice represent an unexpected animal model of primary aldosteronism, which has the particularity to be triggered by sodium restriction. © 2017 American Heart Association, Inc.

  18. Epidermal growth factor receptor signaling mediates aldosterone-induced profibrotic responses in kidney

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sheng, Lili; Yang, Min; Ding, Wei

    Aldosterone has been recognized as a risk factor for the development of chronic kidney disease (CKD). Studies have indicated that enhanced activation of epidermal growth factor receptor (EGFR) is associated with the development and progression of renal fibrosis. But if EGFR is involved in aldosterone-induced renal fibrosis is less investigated. In the present study, we examined the effect of erlotinib, an inhibitor of EGFR tyrosine kinase activity, on the progression of aldosterone-induced renal profibrotic responses in a murine model underwent uninephrectomy. Erlotinib-treated rats exhibited relieved structural lesion comparing with rats treated with aldosterone alone, as characterized by glomerular hypertrophy, mesangialmore » cell proliferation and expansion. Also, erlotinib inhibited the expression of TGF-β, α-SMA and mesangial matrix proteins such as collagen Ⅳ and fibronectin. In cultured mesangial cells, inhibition of EGFR also abrogated aldosterone-induced expression of extracellular matrix proteins, cell proliferation and migration. We also demonstrated that aldosterone induced the phosphorylation of EGFR through generation of ROS. And the activation of EGFR resulted in the phosphorylation of ERK1/2, leading to the activation of profibrotic pathways. Taken together, we concluded that aldosterone-mediated tissue fibrosis relies on ROS induced EGFR/ERK activation, highlighting EGFR as a potential therapeutic target for modulating renal fibrosis. - Highlights: • EGFR was involved in aldosterone-induced renal profibrotic responses. • Aldosterone-induced EGFR activation was mediated by MR-dependent ROS generation. • EGFR activated the MAPK/ERK1/2 signaling to promote renal fibrosis.« less

  19. The effects of infusions of ring-A-reduced derivatives of aldosterone on the antinatriuretic and kaliuretic actions of aldosterone.

    PubMed

    Morris, D J; Souness, G W; Saccoccio, N A; Harnik, M

    1989-01-01

    Infusion of Ring-A-reduced metabolites of aldosterone in adrenalectomized male rats for 4 days revealed that 5 alpha-Ring-A-reduced derivatives, 5 alpha-dihydroaldosterone (5 alpha-DHAldo; 2.5-5.0 micrograms/day), 3 alpha,5 alpha-tetrahydroaldosterone (3 alpha,5 alpha-THAldo; 5-25 micrograms/day), and 3 beta,5 alpha-THAldo (50-175 micrograms/day) possessed intrinsic Na+-retaining activity. The same infusions of 5 alpha-DHAldo, 3 alpha,5 alpha-THAldo, and 3 beta,5 alpha-THAldo, also lowered the urinary excretion of potassium. The 5 beta-Ring-A-reduced derivative 3 alpha,5 beta-THAldo did not demonstrate either of these biological properties. In another set of experiments, on the fourth day of infusion, aldosterone (0.1 microgram/rat) was administered acutely subcutaneously; none of the Ring-A-reduced derivatives altered the Na+-retaining activity of aldosterone. However, in a dose-dependent manner, both 3 alpha,5 alpha-THAldo and 3 beta,5 alpha-THAldo blunted the urinary K+-secretory effect of aldosterone; low dosages of 5 alpha-DHAldo and larger dosages of 3 alpha,5 beta-THAldo did not. Thus, the 5 alpha-reduced derivatives of aldosterone not only lowered urinary Na+ and K+ excretion in their own right, but two of them blunted the kaliuretic response of the parent mineralocorticoid, aldosterone. Further experiments will be required to determine whether these aldosterone metabolites are further metabolized or interconverted during the expression of the regulatory properties described here and whether these properties are physiologically relevant.

  20. Reduced methylation of the thromboxane synthase gene is correlated with its increased vascular expression in preeclampsia.

    PubMed

    Mousa, Ahmad A; Strauss, Jerome F; Walsh, Scott W

    2012-06-01

    Preeclampsia is characterized by increased thromboxane and decreased prostacyclin levels, which predate symptoms, and can explain some of the clinical manifestations of preeclampsia, including hypertension and thrombosis. In this study, we examined DNA methylation of the promoter region of the thromboxane synthase gene (TBXAS1) and the expression of thromboxane synthase in systemic blood vessels of normal pregnant and preeclamptic women. Thromboxane synthase is responsible for the synthesis of thromboxane A(2), a potent vasoconstrictor and activator of platelets. We also examined the effect of experimentally induced DNA hypomethylation on the expression of thromboxane synthase in a neutrophil-like cell line (HL-60 cells) and in cultured vascular smooth muscle and endothelial cells. We found that DNA methylation of the TBXAS1 promoter was decreased and thromboxane synthase expression was increased in omental arteries of preeclamptic women as compared with normal pregnant women. Increased thromboxane synthase expression was observed in vascular smooth muscles cells, endothelial cells, and infiltrating neutrophils. Experimentally induced DNA hypomethylation only increased expression of thromboxane synthase in the neutrophil-like cell line, whereas tumor necrosis factor-α, a neutrophil product, increased its expression in cultured vascular smooth muscle cells. Our study suggests that epigenetic mechanisms and release of tumor necrosis factor-α by infiltrating neutrophils could contribute to the increased expression of thromboxane synthase in maternal systemic blood vessels, contributing to the hypertension and coagulation abnormalities associated with preeclampsia.

  1. Aldosterone Promotes Cardiac Endothelial Cell Proliferation In Vivo

    PubMed Central

    Gravez, Basile; Tarjus, Antoine; Pelloux, Véronique; Ouvrard‐Pascaud, Antoine; Delcayre, Claude; Samuel, Janelise; Clément, Karine; Farman, Nicolette; Jaisser, Fréderic; Messaoudi, Smail

    2015-01-01

    Background Experimentally, aldosterone in association with NaCl induces cardiac fibrosis, oxidative stress, and inflammation through mineralocorticoid receptor activation; however, the biological processes regulated by aldosterone alone in the heart remain to be identified. Methods and Results Mice were treated for 7 days with aldosterone, and then cardiac transcriptome was analyzed. Aldosterone regulated 60 transcripts (51 upregulated and 9 downregulated) in the heart (fold change ≥1.5, false discovery rate <0.01). To identify the biological processes modulated by aldosterone, a gene ontology analysis was performed. The majority of aldosterone‐regulated genes were involved in cell division. The cardiac Ki‐67 index (an index of proliferation) of aldosterone‐treated mice was higher than that of nontreated mice, confirming microarray predictions. Costaining of Ki‐67 with vinculin, CD68, α‐smooth muscle actin, CD31, or caveolin 1 revealed that the cycling cells were essentially endothelial cells. Aldosterone‐induced mineralocorticoid receptor–dependent proliferation was confirmed ex vivo in human endothelial cells. Moreover, pharmacological‐specific blockade of mineralocorticoid receptor by eplerenone inhibited endothelial cell proliferation in a preclinical model of heart failure (transverse aortic constriction). Conclusions Aldosterone modulates cardiac gene expression and induces the proliferation of cardiac endothelial cells in vivo. PMID:25564371

  2. Mechanisms of renal control of potassium homeostasis in complete aldosterone deficiency.

    PubMed

    Todkar, Abhijeet; Picard, Nicolas; Loffing-Cueni, Dominique; Sorensen, Mads V; Mihailova, Marija; Nesterov, Viatcheslav; Makhanova, Natalia; Korbmacher, Christoph; Wagner, Carsten A; Loffing, Johannes

    2015-02-01

    Aldosterone-independent mechanisms may contribute to K(+) homeostasis. We studied aldosterone synthase knockout (AS(-/-)) mice to define renal control mechanisms of K(+) homeostasis in complete aldosterone deficiency. AS(-/-) mice were normokalemic and tolerated a physiologic dietary K(+) load (2% K(+), 2 days) without signs of illness, except some degree of polyuria. With supraphysiologic K(+) intake (5% K(+)), AS(-/-) mice decompensated and became hyperkalemic. High-K(+) diets induced upregulation of the renal outer medullary K(+) channel in AS(-/-) mice, whereas upregulation of the epithelial sodium channel (ENaC) sufficient to increase the electrochemical driving force for K(+) excretion was detected only with a 2% K(+) diet. Phosphorylation of the thiazide-sensitive NaCl cotransporter was consistently lower in AS(-/-) mice than in AS(+/+) mice and was downregulated in mice of both genotypes in response to increased K(+) intake. Inhibition of the angiotensin II type 1 receptor reduced renal creatinine clearance and apical ENaC localization, and caused severe hyperkalemia in AS(-/-) mice. In contrast with the kidney, the distal colon of AS(-/-) mice did not respond to dietary K(+) loading, as indicated by Ussing-type chamber experiments. Thus, renal adaptation to a physiologic, but not supraphysiologic, K(+) load can be achieved in aldosterone deficiency by aldosterone-independent activation of the renal outer medullary K(+) channel and ENaC, to which angiotensin II may contribute. Enhanced urinary flow and reduced activity of the thiazide-sensitive NaCl cotransporter may support renal adaptation by activation of flow-dependent K(+) secretion and increased intratubular availability of Na(+) that can be reabsorbed in exchange for K(+) secreted. Copyright © 2015 by the American Society of Nephrology.

  3. Case Report: Nodule Development From Subcapsular Aldosterone-Producing Cell Clusters Causes Hyperaldosteronism.

    PubMed

    Nishimoto, Koshiro; Seki, Tsugio; Kurihara, Isao; Yokota, Kenichi; Omura, Masao; Nishikawa, Tetsuo; Shibata, Hirotaka; Kosaka, Takeo; Oya, Mototsugu; Suematsu, Makoto; Mukai, Kuniaki

    2016-01-01

    We previously reported that the human adrenal cortex remodels to form subcapsular aldosterone-producing cell clusters (APCCs). Some APCCs were recently found to carry aldosterone-producing adenoma (APA)-associated somatic mutations in ion channel/pump genes, which implied that APCCs produce aldosterone autonomously and are an origin of APA. However, there has been no report describing an APCC-to-APA transitional lesion. A histological examination revealed unilateral multiple adrenocortical micronodules in the adrenals of two patients with primary aldosteronism (PA). Based on immunohistochemistry for aldosterone synthase, some of the micronodules were identified as possible APCC-to-APA transitional lesions (pAATLs; a tentative term used in this manuscript), which consisted of a subcapsular APCC-like portion and an inner micro-APA-like (mAPA-like) portion without an apparent histological border. Genomic DNA samples prepared from pAATL histological sections were analyzed by next-generation sequencing for the known APA-associated mutations. The mAPA-like portions from two of the three large pAATLs examined harbored mutations (KCNJ5 [p.G151R] in pAATL 3 and ATP1A1 [p.L337M] in pAATL 7), whereas their corresponding APCC-like portions did not, suggesting their role in the formation of mAPA. Another lesion carried novel mutations in ATP1A1 (p.Ile322_Ile325del and p.Ile327Ser) in both the mAPA-like and APCC-like portions, thereby supporting these portions having a clonal origin. A novel aldosterone-producing pathology, pAATL that causes unilateral PA, was detected in the adrenals of two patients. Next-generation sequencing analyses of the large pAATLs suggested that the introduction of APA-associated mutations in the ion channel/pump genes may be involved in the development of mAPA from existing APCCs.

  4. Association between urine aldosterone and diastolic function in patients with primary aldosteronism and essential hypertension.

    PubMed

    Chang, Yi-Yao; Lee, Hsiu-Hao; Hung, Chi-Sheng; Wu, Xue-Ming; Lee, Jen-Kuang; Wang, Shuo-Meng; Liao, Min-Tsun; Chen, Ying-Hsien; Wu, Vin-Cent; Wu, Kwan-Dun; Lin, Yen-Hung

    2014-09-01

    To investigate the association between aldosterone and cardiac diastolic dysfunction. We prospectively enrolled 20 patients with primary aldosteronism (PA) and 22 patients with essential hypertension (EH). Plasma aldosterone concentration, plasma renin activity, and 24-h urine aldosterone level were measured. Echocardiography, including tissue Doppler image recordings, was performed. PA patients had a significantly higher left ventricular (LV) mass index and worse LV diastolic function than those in EH patients. Among various measures of aldosterone, log-transformed 24-h urine aldosterone level had the most consistent correlation with diastolic function. Aldosterone is strongly associated with LV diastolic dysfunction. Twenty-four hour urine aldosterone is a good indicator to evaluate the impact of aldosterone on LV diastolic function. Copyright © 2014. Published by Elsevier Inc.

  5. Long-term aldosterone administration increases renal Na+-Cl- cotransporter abundance in late distal convoluted tubule.

    PubMed

    Poulsen, Søren Brandt; Christensen, Birgitte Mønster

    2017-09-01

    Renal Na + -Cl - cotransporter (NCC) is expressed in early distal convoluted tubule (DCT) 1 and late DCT (DCT2). NCC activity can be stimulated by aldosterone administration, and the mechanism is assumed to depend on the enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), which inactivates glucocorticoids that would otherwise occupy aldosterone receptors. Because 11β-HSD2 in rat may only be abundantly expressed in DCT2 cells and not in DCT1 cells, it has been speculated that aldosterone specifically stimulates NCC activity in DCT2 cells. In mice, however, it is debated if 11β-HSD2 is expressed in DCT2 cells. The present study examined whether aldosterone administration in mice stimulates NCC abundance and phosphorylation in DCT2 cells but not in DCT1 cells. B6/C57 male mice were administered 100 µg aldosterone·kg body weight -1 ·24 h -1 for 6 days and euthanized during isoflurane inhalation. Western blotting of whole kidney homogenate showed that aldosterone administration stimulated NCC and pT58-NCC abundances ( P < 0.001). In DCT1 cells, confocal microscopy detected no effect of the aldosterone administration on NCC and pT58-NCC abundances. By contrast, NCC and pT58-NCC abundances were stimulated by aldosterone administration in the middle of DCT2 ( P < 0.001 and <0.01, respectively) and at the junction between DCT2 and CNT ( P < 0.001 and <0.05, respectively). In contrast to rat, immunohistochemistry in mouse showed no/very weak 11β-HSD2 expression in DCT2 cells. Collectively, long-term aldosterone administration stimulates mouse NCC and pT58-NCC abundances in DCT2 cells and presumably not in DCT1 cells. Copyright © 2017 the American Physiological Society.

  6. Vascular Consequences of Aldosterone Excess and Mineralocorticoid Receptor Antagonism.

    PubMed

    Chrissobolis, Sophocles

    2017-01-01

    Aldosterone binds to mineralocorticoid receptors (MRs) on renal epithelial cells to regulate sodium and water reabsorption, and therefore blood pressure. Recently, the actions of aldosterone outside the kidney have been extensively investigated, with numerous reports of aldosterone having detrimental actions, including in the vasculature. Notably, elevated aldosterone levels are an independent cardiovascular risk factor, and in addition to causing an increase in blood pressure, aldosterone can have blood pressure-dependent and -independent effects commonly manifested in the vasculature in cardiovascular diseases, including oxidative stress, endothelial dysfunction, inflammation, remodeling, stiffening, and plaque formation. Receptor-dependent mechanisms mediating these actions include the MR expressed on vascular endothelial and smooth muscle cells, but also include the angiotensin II type 1 receptor, epidermal growth factor receptor and vascular endothelial growth factor receptor 1, with downstream mechanisms including NADPH oxidase, cyclooxygenase, glucose-6-phosphate dehydrogenase, poly-(ADP ribose) polymerase and placental growth factor. The beneficial actions of MR antagonism in experimental hypertension include improved endothelial function, reduced hypertrophy and remodeling, and in atherosclerosis beneficial actions include reduced plaque area, inflammation, oxidative stress and endothelial dysfunction. Aldosterone excess is detrimental and MR antagonism is beneficial in humans also. The emerging concept of the contribution of aldosterone/MR-induced immunity to vascular pathology will also be discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. Acute electroacupuncture inhibits nitric oxide synthase expression in the spinal cord of neuropathic rats.

    PubMed

    Cha, Myeoung Hoon; Bai, Sun Joon; Lee, Kyung Hee; Cho, Zang Hee; Kim, Young-Bo; Lee, Hye-Jung; Lee, Bae Hwan

    2010-02-01

    To examine the effects of electroacupuncture stimulation on behavioral changes and neuronal nitric oxide synthase expression in the rat spinal cord after nerve injury. Under pentobarbital anesthesia, male Sprague-Dawley rats were subjected to neuropathic surgery by tightly ligating and cutting the left tibial and sural nerves. Behavioral responses to mechanical stimulation were tested for 2 weeks post-operatively. At the end of behavioral testing, electroacupuncture stimulation was applied to ST36 (Choksamni) and SP9 (Eumleungcheon) acupoints. Immunocytochemical staining was performed to investigate changes in the expression of neuronal nitric oxide synthase-immunoreactive neurons in the L4-5 spinal cord. Mechanical allodynia was observed by nerve injury. The mechanical allodynia was decreased after electroacupuncture stimulation. Neuronal nitric oxide synthase expression was also decreased in L4-5 spinal cord by electroacupuncture treatment. These results suggest that electroacupuncture relieves mechanical allodynia in the neuropathic rats possibly by the inhibition of neuronal nitric oxide synthase expression in the spinal cord.

  8. TRAF3IP2 Mediates Aldosterone/Salt-Induced Cardiac Hypertrophy and Fibrosis

    PubMed Central

    Sakamuri, Siva S.V.P; Valente, Anthony J.; Siddesha, Jalahalli M.; Delafontaine, Patrice; Siebenlist, Ulrich; Gardner, Jason D.; Chandrasekar, Bysani

    2016-01-01

    Aberrant activation of the renin-angiotensin-aldosterone system (RAAS) contributes to adverse cardiac remodeling and eventual failure. Here we investigated whether TRAF3-interacting Protein 2 (TRAF3IP2), a redox-sensitive cytoplasmic adaptor molecule and an upstream regulator of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1), mediates aldosterone-induced cardiac hypertrophy and fibrosis. Wild type (WT) and TRAF3IP2-null mice were infused with aldosterone (0.2mg/kg/day) for 4 weeks along with 1%NaCl in drinking water. Aldosterone/salt, but not salt alone, upregulated TRAF3IP2 expression in WT mouse hearts. Aldosterone elevated blood pressure to a similar extent in both WT and TRAF3IP2-null groups. Importantly, TRAF3IP2 gene deletion attenuated aldosterone/salt-induced (i) p65 and c-Jun activation, (ii) extracellular matrix (collagen Iα1 and collagen 3α1), matrix metalloproteinase (MMP2), lysyl oxidase (LOX), inflammatory cytokine (IL-6 and IL-18), chemokine (CXCL1 and CXCL2), and adhesion molecule (ICAM1) gene expression in hearts, (iii) IL-6, IL-18, and MMP2 protein levels, (iv) systemic IL-6 and IL-18 levels, and (iv) cardiac hypertrophy and fibrosis. These results indicate that TRAF3IP2 is a critical signaling intermediate in aldosterone/salt-induced myocardial hypertrophy and fibrosis, and thus a potential therapeutic target in hypertensive heart disease. PMID:27040306

  9. Aldosterone Contributes to Sympathoexcitation in Renovascular Hypertension.

    PubMed

    Lincevicius, Gisele S; Shimoura, Caroline G; Nishi, Erika E; Perry, Juliana C; Casarini, Dulce E; Gomes, Guiomar N; Bergamaschi, Cássia T; Campos, Ruy R

    2015-09-01

    Although angiotensin II (Ang II) is essential to the development of renovascular hypertension, aldosterone plays a role as well. Recent studies have demonstrated a cross-talk between Ang II type 1 and mineralocorticoid receptors in the brain and kidneys. However, the role of aldosterone in the autonomic and renal dysfunction of renovascular hypertension is not well understood. The current study evaluated whether aldosterone contributes to cardiovascular and renal dysfunction in the 2 kidney-1 clip (2K1C) model. Mean arterial pressure (MAP) and baroreceptor reflex for control of the heart rate were evaluated in 2K1C treated or not treated with spironolactone (200mg/kg/day, 7 days). Tonic and reflex control of renal sympathetic nerve activity (rSNA) were assessed in urethane-anaesthetized rats. Plasma renin activity (PRA), kidney renin protein expression, renal injury, and central AT1 receptor protein expression were assessed. Spiro reduced MAP (198±4 vs. 170±9mm Hg; P < 0.05), normalized rSNA (147±9 vs. 96±10 pps; P < 0.05), and increased renal baroreceptor reflex sensitivity in the 2K1C rats. Spiro reduced α-smooth muscle actin expression in the nonclipped kidney in the 2K1C group (5±0.6 vs. 1.1±0.2%; P < 0.05). There was no change in PRA; however, a decrease in renin protein expression in the nonclipped kidney was found in the 2K1C treated group (217±30 vs. 160±19%; P < 0.05). Spiro treatment decreased AT1 receptor in the central nervous system (CNS) only in 2K1C rats (138±10 vs. 84±12%; P < 0.05). Aldosterone contributes to autonomic dysfunction and intrarenal injury in 2K1C, these effects are mediated by the CNS. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Aspirin inhibits interleukin 1-induced prostaglandin H synthase expression in cultured endothelial cells

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Wu, K.K.; Sanduja, R.; Tsai, A.L.

    Prostaglandin H (PGH) synthase is a key enzyme in the biosynthesis of prostaglandins, thromboxane, and prostacyclin. In cultured human umbilical vein endothelial cells, interleukin 1 (IL-1) is known to induce the synthesis of this enzyme, thereby raising the level of PGH synthase protein severalfold over the basal level. Pretreatment with aspirin at low concentrations inhibited more than 60% of the enzyme mass and also the cyclooxygenase activity in IL-1-induced cells with only minimal effects on the basal level of the synthase enzyme in cells without IL-1. Sodium salicylate exhibited a similar inhibitory action whereas indomethacin had no apparent effect. Similarlymore » low levels of aspirin inhibited the increased L-({sup 35}S)methionine incorporation into PGH synthase that was induced by IL0-1 and also suppressed expression of the 2.7-kilobase PGH synthase mRNA. These results suggest that in cultured endothelial cells a potent inhibition of eicosanoid biosynthetic capacity can be effected by aspirin or salicylate at the level of PGH synthase gene expression. The aspirin effect may well be due to degradation of salicylate.« less

  11. Expression of inflammation-related genes in aldosterone-producing adenomas with KCNJ5 mutation.

    PubMed

    Murakami, Masanori; Yoshimoto, Takanobu; Nakano, Yujiro; Tsuchiya, Kyoichiro; Minami, Isao; Bouchi, Ryotaro; Fujii, Yasuhisa; Nakabayashi, Kazuhiko; Hashimoto, Koshi; Hata, Ken-Ichiro; Kihara, Kazunori; Ogawa, Yoshihiro

    2016-08-05

    The adrenocortical cells have been shown to produce various inflammatory cytokines such as TNFα and IL-6, which could modulate steroidogenesis. However, the role of inflammatory cytokines in aldosterone-producing adenomas (APAs) is not fully understood. In the present study, we examined the relationships between mRNA expression levels of the inflammation-related genes and somatic mutations in APA tissues. We evaluated mRNA expression levels of TNFA, IL6, and NFKB1 in APA tissues obtained from 44 Japanese APA patients. We revealed that mRNA expression patterns of the inflammation-related genes depended on a KCNJ5 somatic mutation. In addition, we showed that mRNA expression levels of the inflammation-related genes correlated with those of the steroidogenic enzyme CYP11B1 in the patients with APAs. The present study documented for the first time the expression of inflammation-related genes in APAs and the correlation of their expression levels with the KCNJ5 mutation status and mRNA expression levels of steroidogenic enzymes, indicating the pathophysiological relevance of inflammation-related genes in APAs. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Expression and Activity of Nitric Oxide Synthase Isoforms in Methamphetamine-Induced Striatal Dopamine Toxicity

    PubMed Central

    Friend, Danielle M.; Son, Jong H.; Keefe, Kristen A.

    2013-01-01

    Nitric oxide is implicated in methamphetamine (METH)-induced neurotoxicity; however, the source of the nitric oxide has not been identified. Previous work has also revealed that animals with partial dopamine loss induced by a neurotoxic regimen of methamphetamine fail to exhibit further decreases in striatal dopamine when re-exposed to methamphetamine 7–30 days later. The current study examined nitric oxide synthase expression and activity and protein nitration in striata of animals administered saline or neurotoxic regimens of methamphetamine at postnatal days 60 and/or 90, resulting in four treatment groups: Saline:Saline, METH:Saline, Saline:METH, and METH:METH. Acute administration of methamphetamine on postnatal day 90 (Saline:METH and METH:METH) increased nitric oxide production, as evidenced by increased protein nitration. Methamphetamine did not, however, change the expression of endothelial or inducible isoforms of nitric oxide synthase, nor did it change the number of cells positive for neuronal nitric oxide synthase mRNA expression or the amount of neuronal nitric oxide synthase mRNA per cell. However, nitric oxide synthase activity in striatal interneurons was increased in the Saline:METH and METH:METH animals. These data suggest that increased nitric oxide production after a neurotoxic regimen of methamphetamine results from increased nitric oxide synthase activity, rather than an induction of mRNA, and that constitutively expressed neuronal nitric oxide synthase is the most likely source of nitric oxide after methamphetamine administration. Of interest, animals rendered resistant to further methamphetamine-induced dopamine depletions still show equivalent degrees of methamphetamine-induced nitric oxide production, suggesting that nitric oxide production alone in response to methamphetamine is not sufficient to induce acute neurotoxic injury. PMID:23230214

  13. TRAF3IP2 mediates aldosterone/salt-induced cardiac hypertrophy and fibrosis.

    PubMed

    Sakamuri, Siva S V P; Valente, Anthony J; Siddesha, Jalahalli M; Delafontaine, Patrice; Siebenlist, Ulrich; Gardner, Jason D; Bysani, Chandrasekar

    2016-07-05

    Aberrant activation of the renin-angiotensin-aldosterone system (RAAS) contributes to adverse cardiac remodeling and eventual failure. Here we investigated whether TRAF3 Interacting Protein 2 (TRAF3IP2), a redox-sensitive cytoplasmic adaptor molecule and an upstream regulator of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1), mediates aldosterone-induced cardiac hypertrophy and fibrosis. Wild type (WT) and TRAF3IP2-null mice were infused with aldosterone (0.2 mg/kg/day) for 4 weeks along with 1%NaCl in drinking water. Aldosterone/salt, but not salt alone, upregulated TRAF3IP2 expression in WT mouse hearts. Further, aldosterone elevated blood pressure to a similar extent in both WT and TRAF3IP2-null groups. However, TRAF3IP2 gene deletion attenuated aldosterone/salt-induced (i) p65 and c-Jun activation, (ii) extracellular matrix (collagen Iα1 and collagen IIIα1), matrix metalloproteinase (MMP2), lysyl oxidase (LOX), inflammatory cytokine (IL-6 and IL-18), chemokine (CXCL1 and CXCL2), and adhesion molecule (ICAM1) mRNA expression in hearts, (iii) IL-6, IL-18, and MMP2 protein levels, (iv) systemic IL-6 and IL-18 levels, and (iv) cardiac hypertrophy and fibrosis. These results indicate that TRAF3IP2 is a critical signaling intermediate in aldosterone/salt-induced myocardial hypertrophy and fibrosis, and thus a potential therapeutic target in hypertensive heart disease. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  14. Obstructive Sleep Apnea and Aldosterone

    PubMed Central

    Svatikova, Anna; Olson, Lyle J.; Wolk, Robert; Phillips, Bradley G.; Adachi, Taro; Schwartz, Gary L.; Somers, Virend K.

    2009-01-01

    Background: Obstructive sleep apnea (OSA) is a major risk factor for hypertension and has been associated with increased risk for cardiovascular morbidity. A dysregulated renin-angiotensin-aldosterone system may contribute to excess sodium retention and hypertension and may be activated in OSA. We tested the hypothesis that serum levels of aldosterone and plasma renin activity (PRA) are increased by apneic sleep in subjects without cardiovascular disease, compared to healthy control subjects. Methods and Results: Plasma aldosterone level was measured in 21 subjects with moderate to severe OSA and was compared to 19 closely matched healthy subjects. Plasma renin activity (PRA) was measured in 19 OSA patients and in 20 healthy controls. Aldosterone and PRA were measured before sleep (9pm), after 5 hrs of untreated OSA (2am) and in the morning after awakening (6am). There were no baseline (9pm) differences in serum aldosterone levels and PRA between the healthy controls and OSA patients (aldosterone: 55.2 ± 9 vs 56.0 ± 9 pg/mL; PRA: 0.99 ± 0.15 vs 1.15 ± 0.15 ng/mL/hr). Neither several hours of untreated severe OSA nor CPAP treatment affected aldosterone levels and PRA in OSA patients. Diurnal variation of both aldosterone and PRA was observed in both groups, in that morning renin and aldosterone levels were higher than those measured at night before sleep. Conclusions: Our study shows that patients with moderate to severe OSA without co-existing cardiovascular disease have plasma aldosterone and renin levels similar to healthy subjects. Neither untreated OSA nor CPAP treatment acutely affect plasma aldosterone or renin levels. Citation: Svatikova A; Olson LJ; Wolk R; Phillips BG; Adachi T; Schwartz GL; Somers VK. Obstructive sleep apnea and aldosterone. SLEEP 2009;32(12):1589-1592. PMID:20041594

  15. Hypokalemia and Pendrin Induction by Aldosterone.

    PubMed

    Xu, Ning; Hirohama, Daigoro; Ishizawa, Kenichi; Chang, Wen Xiu; Shimosawa, Tatsuo; Fujita, Toshiro; Uchida, Shunya; Shibata, Shigeru

    2017-05-01

    Aldosterone plays an important role in regulating Na-Cl reabsorption and blood pressure. Epithelial Na + channel, Na + -Cl - cotransporter, and Cl - /HCO 3 - exchanger pendrin are the major mediators of Na-Cl transport in the aldosterone-sensitive distal nephron. Existing evidence also suggests that plasma K + concentration affects renal Na-Cl handling. In this study, we posited that hypokalemia modulates the effects of aldosterone on pendrin in hyperaldosteronism. Chronic aldosterone infusion in mice increased pendrin levels at the plasma membrane, and correcting hypokalemia in this model almost completely blocked pendrin upregulation. However, hypokalemia induced by a low-K + diet resulted in pendrin downregulation along with reduced plasma aldosterone levels, indicating that both hypokalemia and aldosterone excess are necessary for pendrin induction. In contrast, decreased plasma K + levels were sufficient to increase Na + -Cl - cotransporter levels. We found that phosphorylation of mineralocorticoid receptor that prevents aldosterone binding in intercalated cells was suppressed by hypokalemia, which resulted in enhanced pendrin response to aldosterone, explaining the coordinated action of aldosterone and hypokalemia in pendrin regulation. Finally, to address the physiological significance of our observations, we administered aldosterone to mice lacking pendrin. Notably, plasma K + levels were significantly lower in pendrin knockout mice (2.7±0.1 mmol/L) than in wild-type mice (3.0±0.1 mmol/L) after aldosterone infusion, demonstrating that pendrin alleviates hypokalemia in a state of aldosterone excess. These data indicate that the decreased plasma K + levels promote pendrin induction by aldosterone, which, in concert with Na + -Cl - cotransporter, counteracts the progression of hypokalemia but promotes hypertension in primary aldosterone excess. © 2017 American Heart Association, Inc.

  16. Seasonal influence on gene expression of monoterpene synthases in Salvia officinalis (Lamiaceae).

    PubMed

    Grausgruber-Gröger, Sabine; Schmiderer, Corinna; Steinborn, Ralf; Novak, Johannes

    2012-03-01

    Garden sage (Salvia officinalis L., Lamiaceae) is one of the most important medicinal and aromatic plants and possesses antioxidant, antimicrobial, spasmolytic, astringent, antihidrotic and specific sensorial properties. The essential oil of the plant, formed mainly in very young leaves, is in part responsible for these activities. It is mainly composed of the monoterpenes 1,8-cineole, α- and β-thujone and camphor synthesized by the 1,8-cineole synthase, the (+)-sabinene synthase and the (+)-bornyl diphosphate synthase, respectively, and is produced and stored in epidermal glands. In this study, the seasonal influence on the formation of the main monoterpenes in young, still expanding leaves of field-grown sage plants was studied in two cultivars at the level of mRNA expression, analyzed by qRT-PCR, and at the level of end-products, analyzed by gas chromatography. All monoterpene synthases and monoterpenes were significantly influenced by cultivar and season. 1,8-Cineole synthase and its end product 1,8-cineole remained constant until August and then decreased slightly. The thujones increased steadily during the vegetative period. The transcript level of their corresponding terpene synthase, however, showed its maximum in the middle of the vegetative period and declined afterwards. Camphor remained constant until August and then declined, exactly correlated with the mRNA level of the corresponding terpene synthase. In summary, terpene synthase mRNA expression and respective end product levels were concordant in the case of 1,8-cineole (r=0.51 and 0.67 for the two cultivars, respectively; p<0.05) and camphor (r=0.75 and 0.82; p<0.05) indicating basically transcriptional control, but discordant for α-/β-thujone (r=-0.05 and 0.42; p=0.87 and 0.13, respectively). Copyright © 2011 Elsevier GmbH. All rights reserved.

  17. Calpain-10 Activity Underlies Angiotensin II-Induced Aldosterone Production in an Adrenal Glomerulosa Cell Model

    PubMed Central

    Seremwe, Mutsa; Schnellmann, Rick G.

    2015-01-01

    Aldosterone is a steroid hormone important in the regulation of blood pressure. Aberrant production of aldosterone results in the development and progression of diseases including hypertension and congestive heart failure; therefore, a complete understanding of aldosterone production is important for developing more effective treatments. Angiotensin II (AngII) regulates steroidogenesis, in part through its ability to increase intracellular calcium levels. Calcium can activate calpains, proteases classified as typical or atypical based on the presence or absence of penta-EF-hands, which are involved in various cellular responses. We hypothesized that calpain, in particular calpain-10, is activated by AngII in adrenal glomerulosa cells and underlies aldosterone production. Our studies showed that pan-calpain inhibitors reduced AngII-induced aldosterone production in 2 adrenal glomerulosa cell models, primary bovine zona glomerulosa and human adrenocortical carcinoma (HAC15) cells, as well as CYP11B2 expression in the HAC15 cells. Although AngII induced calpain activation in these cells, typical calpain inhibitors had no effect on AngII-elicited aldosterone production, suggesting a lack of involvement of classical calpains in this process. However, an inhibitor of the atypical calpain, calpain-10, decreased AngII-induced aldosterone production. Consistent with this result, small interfering RNA (siRNA)-mediated knockdown of calpain-10 inhibited aldosterone production and CYP11B2 expression, whereas adenovirus-mediated overexpression of calpain-10 resulted in increased AngII-induced aldosterone production. Our results indicate that AngII-induced activation of calpain-10 in glomerulosa cells underlies aldosterone production and identify calpain-10 or its downstream pathways as potential targets for the development of drug therapies for the treatment of hypertension. PMID:25836666

  18. Aldosterone down-regulates the slowly activated delayed rectifier potassium current in adult guinea pig cardiomyocytes.

    PubMed

    Lv, Yankun; Bai, Song; Zhang, Hua; Zhang, Hongxue; Meng, Jing; Li, Li; Xu, Yanfang

    2015-12-01

    There is emerging evidence that the mineralocorticoid hormone aldosterone is associated with arrhythmias in cardiovascular disease. However, the effect of aldosterone on the slowly activated delayed rectifier potassium current (IK s ) remains poorly understood. The present study was designed to investigate the modulation of IK s by aldosterone. Adult guinea pigs were treated with aldosterone for 28 days via osmotic pumps. Standard glass microelectrode recordings and whole-cell patch-clamp techniques were used to record action potentials in papillary muscles and IK s in ventricular cardiomyocytes. The aldosterone-treated animals exhibited a prolongation of the QT interval and action potential duration with a higher incidence of early afterdepolarizations. Patch-clamp recordings showed a significant down-regulation of IK s density in the ventricular myocytes of these treated animals. These aldosterone-induced electrophysiological changes were fully prevented by a combined treatment with spironolactone, a mineralocorticoid receptor (MR) antagonist. In addition, in in vitro cultured ventricular cardiomyocytes, treatment with aldosterone (sustained exposure for 24 h) decreased the IK s density in a concentration-dependent manner. Furthermore, a significant corresponding reduction in the mRNA/protein expression of IKs channel pore and auxiliary subunits, KCNQ1 and KCNE1 was detected in ventricular tissue from the aldosterone-treated animals. Aldosterone down-regulates IK s by inhibiting the expression of KCNQ1 and KCNE1, thus delaying the ventricular repolarization. These results provide new insights into the mechanism underlying K(+) channel remodelling in heart disease and may explain the highly beneficial effects of MR antagonists in HF. © 2015 The British Pharmacological Society.

  19. Aldosteronism and hypertension.

    PubMed

    Calhoun, David A

    2006-09-01

    A growing body of evidence suggests that hyperaldosteronism contributes significantly to the development and the severity of hypertension as well as to resistance to antihypertensive treatment. In cross-sectional analyses, plasma aldosterone levels have been shown to relate to BP levels, particularly in obese individuals. In these same individuals, BP was not related to plasma renin activity, suggesting an effect of aldosterone on BP independent of renin-angiotensin II. In a recent prospective analysis from the Framingham investigators, baseline serum aldosterone was strongly associated with development of hypertension during a 4-yr follow-up.

  20. Discordance between imaging and immunohistochemistry in unilateral primary aldosteronism.

    PubMed

    Nanba, Aya T; Nanba, Kazutaka; Byrd, James B; Shields, James J; Giordano, Thomas J; Miller, Barbara S; Rainey, William E; Auchus, Richard J; Turcu, Adina F

    2017-12-01

    Correct subtyping of primary aldosteronism (PA) is essential for good surgical outcomes. Adrenal vein sampling (AVS) and/or computed tomography (CT) are used for PA subclassification. Clinical and/or biochemical improvement after surgery, however, is not always achieved in patients with presumed unilateral PA. We aimed to identify the pitfalls in PA subclassification leading to surgical treatment failures. We retrospectively studied 208 patients who underwent adrenal vein sampling (AVS) for PA subclassification in a tertiary referral centre, between January 2009 and August 2016. Simultaneous bilateral AVS was performed before and after cosyntropin administration. We implemented immunohistochemistry for aldosterone synthase (CYP11B2) and 17α-hydroxylase/17,20 lyase (CYP17A1) in adrenal glands resected from patients without improvement of PA after surgical treatment and from those with limitations in AVS interpretation. Of 55 patients who underwent adrenalectomy, three (5.5%) had no improvement of PA. All three patients underwent partial adrenalectomy to remove a CT-detected nodule present on the same side with AVS lateralization. Immunohistochemistry revealed a CYP11B2-negative nodule in both cases available. All patients who underwent total adrenalectomy based on AVS lateralization benefitted from surgery, including three patients with unilateral unsuccessful AVS and aldosterone suppression in the catheterized side vs inferior vena cava. Radiographically identified adrenal nodules are not always a source of PA, even when ipsilateral with AVS lateralization. These data caution against reliance on imaging findings, either alone or in conjunction with AVS, to guide surgery for PA. © 2017 John Wiley & Sons Ltd.

  1. Studies on the Expression of Sesquiterpene Synthases Using Promoter-β-Glucuronidase Fusions in Transgenic Artemisia annua L

    PubMed Central

    Wang, Hongzhen; Han, Junli; Kanagarajan, Selvaraju; Lundgren, Anneli; Brodelius, Peter E.

    2013-01-01

    In order to better understand the influence of sesquiterpene synthases on artemisinin yield in Artemisia annua, the expression of some sesquiterpene synthases has been studied using transgenic plants expressing promoter-GUS fusions. The cloned promoter sequences were 923, 1182 and 1510 bp for β-caryophyllene (CPS), epi-cedrol (ECS) and β-farnesene (FS) synthase, respectively. Prediction of cis-acting regulatory elements showed that the promoters are involved in complex regulation of expression. Transgenic A. annua plants carrying promoter-GUS fusions were studied to elucidate the expression pattern of the three sesquiterpene synthases and compared to the previously studied promoter of amorpha-4,11-diene synthase (ADS), a key enzyme of artemisinin biosynthesis. The CPS and ECS promoters were active in T-shaped trichomes of leaves and stems, basal bracts of flower buds and also in some florets cells but not in glandular secretory trichome while FS promoter activity was only observed in leaf cells and trichomes of transgenic shoots. ADS, CPS, ECS and FS transcripts were induced by wounding in a time depended manner. The four sesquiterpene synthases may be involved in responsiveness of A. annua to herbivory. Methyl jasmonate treatment triggered activation of the promoters of all four sesquiterpene synthases in a time depended manner. Southern blot result showed that the GUS gene was inserted into genomic DNA of transgenic lines as a single copy or two copies. The relative amounts of CPS and ECS as well as germacrene A synthase (GAS) transcripts are much lower than that of ADS transcript. Consequently, down-regulation of the expression of the CPS, ECS or GAS gene may not improve artemsinin yield. However, blocking the expression of FS may have effects on artemisinin production. PMID:24278301

  2. Aldosterone Induces Renal Fibrosis and Inflammatory M1-Macrophage Subtype via Mineralocorticoid Receptor in Rats

    PubMed Central

    Martín-Fernández, Beatriz; Rubio-Navarro, Alfonso; Cortegano, Isabel; Ballesteros, Sandra; Alía, Mario; Cannata-Ortiz, Pablo; Olivares-Álvaro, Elena; Egido, Jesús; de Andrés, Belén; Gaspar, María Luisa; de las Heras, Natalia; Lahera, Vicente; Moreno, Juan Antonio

    2016-01-01

    We aimed to evaluate macrophages heterogeneity and structural, functional and inflammatory alterations in rat kidney by aldosterone + salt administration. The effects of treatment with spironolactone on above parameters were also analyzed. Male Wistar rats received aldosterone (1 mgkg-1d-1) + 1% NaCl for 3 weeks. Half of the animals were treated with spironolactone (200 mg kg-1d-1). Systolic and diastolic blood pressures were elevated (p<0.05) in aldosterone + salt–treated rats. Relative kidney weight, collagen content, fibronectin, macrophage infiltrate, CTGF, Col I, MMP2, TNF-α, CD68, Arg2, and SGK-1 were increased (p<0.05) in aldosterone + salt–treated rats, being reduced by spironolactone (p<0.05). Increased iNOS and IFN-γ mRNA gene expression (M1 macrophage markers) was observed in aldosterone + salt rats, whereas no significant differences were observed in IL-10 and gene ArgI mRNA expression or ED2 protein content (M2 macrophage markers). All the observed changes were blocked with spironolactone treatment. Macrophage depletion with liposomal clodronate reduced macrophage influx and inflammatory M1 markers (INF-γ or iNOS), whereas interstitial fibrosis was only partially reduced after this intervention, in aldosterone plus salt-treated rats. In conclusion, aldosterone + salt administration mediates inflammatory M1 macrophage phenotype and increased fibrosis throughout mineralocorticoid receptors activation. PMID:26730742

  3. Abnormal aldosterone physiology and cardiometabolic risk factors.

    PubMed

    Vaidya, Anand; Underwood, Patricia C; Hopkins, Paul N; Jeunemaitre, Xavier; Ferri, Claudio; Williams, Gordon H; Adler, Gail K

    2013-04-01

    Abnormal aldosterone physiology has been implicated in the pathogenesis of cardiometabolic diseases. Single aldosterone measurements capture only a limited range of aldosterone physiology. New methods of characterizing aldosterone physiology may provide a more comprehensive understanding of its relationship with cardiometabolic disease. We evaluated whether novel indices of aldosterone responses to dietary sodium modulation, the sodium-modulated aldosterone suppression-stimulation index (SASSI for serum and SAUSSI for urine), could predict cardiometabolic risk factors. We performed cross-sectional analyses on 539 subjects studied on liberal and restricted sodium diets with serum and urinary aldosterone measurements. SASSI and SAUSSI were calculated as the ratio of aldosterone on liberal (maximally suppressed aldosterone) to the aldosterone on restricted (stimulated aldosterone) diets and associated with risk factors using adjusted regression models. Cardiometabolic risk factors associated with either impaired suppression of aldosterone on liberal diet, or impaired stimulation on restricted diet, or both; in all of these individual cases, these risk factors associated with higher SASSI or SAUSSI. In the context of abnormalities that constitute the metabolic syndrome, there was a strong positive association between the number of metabolic syndrome components (0-4) and both SASSI and SAUSSI (P<0.0001) that was independent of known aldosterone secretagogues (angiotensin II, corticotropin, potassium). SASSI and SAUSSI exhibited a high sensitivity in detecting normal individuals with zero metabolic syndrome components (86% for SASSI and 83% for SAUSSI). Assessing the physiological range of aldosterone responses may provide greater insights into adrenal pathophysiology. Dysregulated aldosterone physiology may contribute to, or result from, early cardiometabolic abnormalities.

  4. Cistrome of the aldosterone-activated mineralocorticoid receptor in human renal cells.

    PubMed

    Le Billan, Florian; Khan, Junaid A; Lamribet, Khadija; Viengchareun, Say; Bouligand, Jérôme; Fagart, Jérôme; Lombès, Marc

    2015-09-01

    Aldosterone exerts its effects mainly by activating the mineralocorticoid receptor (MR), a transcription factor that regulates gene expression through complex and dynamic interactions with coregulators and transcriptional machinery, leading to fine-tuned control of vectorial ionic transport in the distal nephron. To identify genome-wide aldosterone-regulated MR targets in human renal cells, we set up a chromatin immunoprecipitation (ChIP) assay by using a specific anti-MR antibody in a differentiated human renal cell line expressing green fluorescent protein (GFP)-MR. This approach, coupled with high-throughput sequencing, allowed identification of 974 genomic MR targets. Computational analysis identified an MR response element (MRE) including single or multiple half-sites and palindromic motifs in which the AGtACAgxatGTtCt sequence was the most prevalent motif. Most genomic MR-binding sites (MBSs) are located >10 kb from the transcriptional start sites of target genes (84%). Specific aldosterone-induced recruitment of MR on the first most relevant genomic sequences was further validated by ChIP-quantitative (q)PCR and correlated with concomitant and positive aldosterone-activated transcriptional regulation of the corresponding gene, as assayed by RT-qPCR. It was notable that most MBSs lacked MREs but harbored DNA recognition motifs for other transcription factors (FOX, EGR1, AP1, PAX5) suggesting functional interaction. This work provides new insights into aldosterone MR-mediated renal signaling and opens relevant perspectives for mineralocorticoid-related pathophysiology. © FASEB.

  5. Heterologous expression of an active chitin synthase from Rhizopus oryzae.

    PubMed

    Salgado-Lugo, Holjes; Sánchez-Arreguín, Alejandro; Ruiz-Herrera, José

    2016-12-01

    Chitin synthases are highly important enzymes in nature, where they synthesize structural components in species belonging to different eukaryotic kingdoms, including kingdom Fungi. Unfortunately, their structure and the molecular mechanism of synthesis of their microfibrilar product remain largely unknown, probably because no fungal active chitin synthases have been isolated, possibly due to their extreme hydrophobicity. In this study we have turned to the heterologous expression of the transcript from a small chitin synthase of Rhizopus oryzae (RO3G_00942, Chs1) in Escherichia coli. The enzyme was active, but accumulated mostly in inclusion bodies. High concentrations of arginine or urea solubilized the enzyme, but their dilution led to its denaturation and precipitation. Nevertheless, use of urea permitted the purification of small amounts of the enzyme. The properties of Chs1 (Km, optimum temperature and pH, effect of GlcNAc) were abnormal, probably because it lacks the hydrophobic transmembrane regions characteristic of chitin synthases. The product of the enzyme showed that, contrasting with chitin made by membrane-bound Chs's and chitosomes, was only partially in the form of short microfibrils of low crystallinity. This approach may lead to future developments to obtain active chitin synthases that permit understanding their molecular mechanism of activity, and microfibril assembly. Copyright © 2016. Published by Elsevier Inc.

  6. Primary aldosteronism: diagnosis and treatment.

    PubMed

    Pimenta, Eduardo; Calhoun, David A

    2006-12-01

    Recent studies have indicated a higher prevalence of primary aldosteronism (PA) than reported historically. Aldosterone excess induces sodium and fluid retention with consequential increases in blood pressure. Patients with PA are at an increased risk of developing left ventricular hypertrophy, chronic kidney disease, and endothelial dysfunction. Measurement of the plasma aldosterone/plasma renin activity ratio is an effective screening test for PA. The majority of patients with PA do not have a discernable aldosterone-producing adenoma (APA), and the aldosterone excess is considered idiopathic in etiology and/or attributed to adrenal hyperplasia. Treatment of PA includes medical therapy with mineralocorticoid receptor antagonists and adrenalectomy for patients with a unilateral APA. A reasonable treatment strategy is to attempt medical therapy in all patients with a high plasma aldosterone/PRA ratio and reserve the extensive workup needed to identify an APA for those patients whose hypertension or hypokalemia cannot be controlled medically.

  7. A MicroRNA Cluster miR-23-24-27 Is Upregulated by Aldosterone in the Distal Kidney Nephron Where it Alters Sodium Transport.

    PubMed

    Liu, Xiaoning; Edinger, Robert S; Klemens, Christine A; Phua, Yu L; Bodnar, Andrew J; LaFramboise, William A; Ho, Jacqueline; Butterworth, Michael B

    2017-06-01

    The epithelial sodium channel (ENaC) is expressed in the epithelial cells of the distal convoluted tubules, connecting tubules, and cortical collecting duct (CCD) in the kidney nephron. Under the regulation of the steroid hormone aldosterone, ENaC is a major determinant of sodium (Na + ) and water balance. The ability of aldosterone to regulate microRNAs (miRs) in the kidney has recently been realized, but the role of miRs in Na + regulation has not been well established. Here we demonstrate that expression of a miR cluster mmu-miR-23-24-27, is upregulated in the CCD by aldosterone stimulation both in vitro and in vivo. Increasing the expression of these miRs increased Na + transport in the absence of aldosterone stimulation. Potential miR targets were evaluated and miR-27a/b was verified to bind to the 3'-untranslated region of intersectin-2, a multi-domain protein expressed in the distal kidney nephron and involved in the regulation of membrane trafficking. Expression of Itsn2 mRNA and protein was decreased after aldosterone stimulation. Depletion of Itsn2 expression, mimicking aldosterone regulation, increased ENaC-mediated Na + transport, while Itsn2 overexpression reduced ENaC's function. These findings reinforce a role for miRs in aldosterone regulation of Na + transport, and implicate miR-27 in aldosterone's action via a novel target. J. Cell. Physiol. 232: 1306-1317, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  8. Aldosterone antagonists in heart failure.

    PubMed

    Miller, Susan E; Alvarez, René J

    2013-01-01

    Chronic, systolic heart failure is an increasing and costly health problem, and treatments based on pathophysiology have evolved that include the use of aldosterone antagonists. Advances in the understanding of neurohormonal responses to heart failure have led to better pharmacologic treatments. The steroid hormone aldosterone has been associated with detrimental effects on the cardiovascular system, such as ventricular remodeling and endothelial dysfunction. This article will review the literature and guidelines that support the use of aldosterone antagonists in the treatment of chronic, systolic heart failure. Aldosterone antagonists are life-saving drugs that have been shown to decrease mortality in patients with New York Heart Association class III to IV heart failure and in patients with heart failure after an acute myocardial infarction. Additional studies are being conducted to determine if the role of aldosterone antagonists can be expanded to patients with less severe forms of heart failure. Aldosterone antagonists are an important pharmacologic therapy in the neurohormonal blockade necessary in the treatment of systolic heart failure. These drugs have been shown to decrease mortality and reduce hospital readmission rates. The major complication of aldosterone antagonists is hyperkalemia, which can be avoided with appropriate patient selection and diligent monitoring.

  9. 2-Methyl-3-buten-2-ol (MBO) synthase expression in Nostoc punctiforme leads to over production of phytols.

    PubMed

    Gupta, Dinesh; Ip, Tina; Summers, Michael L; Basu, Chhandak

    2015-01-01

    Phytol is a diterpene alcohol of medicinal importance and it also has potential to be used as biofuel. We found over production of phytol in Nostoc punctiforme by expressing a 2-Methyl-3-buten-2-ol (MBO) synthase gene. MBO synthase catalyzes the conversion of dimethylallyl pyrophosphate (DMAPP) into MBO, a volatile hemiterpene alcohol, in Pinus sabiniana. The result of enhanced phytol production in N. punctiforme, instead of MBO, could be explained by one of the 2 models: either the presence of a native prenyltransferase enzyme with a broad substrate specificity, or appropriation of a MBO synthase metabolic intermediate by a native geranyl diphosphate (GDP) synthase. In this work, an expression vector with an indigenous petE promoter for gene expression in the cyanobacterium N. punctiforme was constructed and MBO synthase gene expression was successfully shown using reverse transcriptase (RT)-PCR and SDS-PAGE. Gas chromatography--mass spectrophotometry (GC-MS) was performed to confirm phytol production from the transgenic N. punctiforme strains. We conclude that the expression of MBO synthase in N. punctiforme leads to overproduction of an economically important compound, phytol. This study provides insights about metabolic channeling of isoprenoids in cyanobacteria and also illustrates the challenges of bioengineering non-native hosts to produce economically important compounds.

  10. Altered expression of the caffeine synthase gene in a naturally caffeine-free mutant of Coffea arabica.

    PubMed

    Maluf, Mirian Perez; da Silva, Carla Cristina; de Oliveira, Michelle de Paula Abreu; Tavares, Aline Gomes; Silvarolla, Maria Bernadete; Guerreiro, Oliveiro

    2009-10-01

    In this work, we studied the biosynthesis of caffeine by examining the expression of genes involved in this biosynthetic pathway in coffee fruits containing normal or low levels of this substance. The amplification of gene-specific transcripts during fruit development revealed that low-caffeine fruits had a lower expression of the theobromine synthase and caffeine synthase genes and also contained an extra transcript of the caffeine synthase gene. This extra transcript contained only part of exon 1 and all of exon 3. The sequence of the mutant caffeine synthase gene revealed the substitution of isoleucine for valine in the enzyme active site that probably interfered with enzymatic activity. These findings indicate that the absence of caffeine in these mutants probably resulted from a combination of transcriptional regulation and the presence of mutations in the caffeine synthase amino acid sequence.

  11. Altered expression of the caffeine synthase gene in a naturally caffeine-free mutant of Coffea arabica

    PubMed Central

    2009-01-01

    In this work, we studied the biosynthesis of caffeine by examining the expression of genes involved in this biosynthetic pathway in coffee fruits containing normal or low levels of this substance. The amplification of gene-specific transcripts during fruit development revealed that low-caffeine fruits had a lower expression of the theobromine synthase and caffeine synthase genes and also contained an extra transcript of the caffeine synthase gene. This extra transcript contained only part of exon 1 and all of exon 3. The sequence of the mutant caffeine synthase gene revealed the substitution of isoleucine for valine in the enzyme active site that probably interfered with enzymatic activity. These findings indicate that the absence of caffeine in these mutants probably resulted from a combination of transcriptional regulation and the presence of mutations in the caffeine synthase amino acid sequence. PMID:21637458

  12. High potassium promotes mutual interaction between (pro)renin receptor and the local renin-angiotensin-aldosterone system in rat inner medullary collecting duct cells.

    PubMed

    Xu, Chuanming; Fang, Hui; Zhou, Li; Lu, Aihua; Yang, Tianxin

    2016-10-01

    (Pro)renin receptor (PRR) is predominantly expressed in the collecting duct (CD) with unclear functional implication. It is not known whether CD PRR is regulated by high potassium (HK). Here, we aimed to investigate the effect of HK on PRR expression and its role in regulation of aldosterone synthesis and release in the CD. In primary rat inner medullary CD cells, HK augmented PRR expression and soluble PPR (sPRR) release in a time- and dose-dependent manner, which was attenuated by PRR small interfering RNA (siRNA), eplerenone, and losartan. HK upregulated aldosterone release in parallel with an increase of CYP11B2 (cytochrome P-450, family 11, subfamily B, polypeptide 2) protein expression and upregulation of medium renin activity, both of which were attenuated by a PRR antagonist PRO20, PRR siRNA, eplerenone, and losartan. Similarly, prorenin upregulated aldosterone release and CYP11B2 expression, both of which were attenuated by PRR siRNA. Interestingly, a recombinant sPRR (sPRR-His) also stimulated aldosterone release and CYP11B2 expression. Taken together, we conclude that HK enhances a local renin-angiotensin-aldosterone system (RAAS), leading to increased PRR expression, which in turn amplifies the response of the RAAS, ultimately contributing to heightened aldosterone release.

  13. High potassium promotes mutual interaction between (pro)renin receptor and the local renin-angiotensin-aldosterone system in rat inner medullary collecting duct cells

    PubMed Central

    Xu, Chuanming; Fang, Hui; Zhou, Li; Lu, Aihua

    2016-01-01

    (Pro)renin receptor (PRR) is predominantly expressed in the collecting duct (CD) with unclear functional implication. It is not known whether CD PRR is regulated by high potassium (HK). Here, we aimed to investigate the effect of HK on PRR expression and its role in regulation of aldosterone synthesis and release in the CD. In primary rat inner medullary CD cells, HK augmented PRR expression and soluble PPR (sPRR) release in a time- and dose-dependent manner, which was attenuated by PRR small interfering RNA (siRNA), eplerenone, and losartan. HK upregulated aldosterone release in parallel with an increase of CYP11B2 (cytochrome P-450, family 11, subfamily B, polypeptide 2) protein expression and upregulation of medium renin activity, both of which were attenuated by a PRR antagonist PRO20, PRR siRNA, eplerenone, and losartan. Similarly, prorenin upregulated aldosterone release and CYP11B2 expression, both of which were attenuated by PRR siRNA. Interestingly, a recombinant sPRR (sPRR-His) also stimulated aldosterone release and CYP11B2 expression. Taken together, we conclude that HK enhances a local renin-angiotensin-aldosterone system (RAAS), leading to increased PRR expression, which in turn amplifies the response of the RAAS, ultimately contributing to heightened aldosterone release. PMID:27534754

  14. Nitric oxide synthase expression in foetal placentas of cows with retained fetal membranes.

    PubMed

    Shixin, Fu; Li, Zhang; Chunhai, Luo; Chuang, Xu; Cheng, Xia; Zhe, Wang; Xiaobing, Li

    2011-10-01

    The objectives of this study were to investigate relationship of retained fetal membranes (RFM) to expression of NOS and NOS mRNA and to analyze pathohistological changes and the distribution of nitric oxide synthase (NOS) in foetal placentas of cows with RFM. Twenty cows were assigned to two groups, a control group (no retained fetal membranes, NRFM, n = 10) and a diseased group (RFM, n = 10). The endpoint method was used to detect the nitric oxide (NO) content and nitric oxide synthase (NOS) activity in foetal placental tissue fluid and the fluorescent quantitation PCR was used to measure the expression of NOS mRNA. Immunohistochemistry and hematoxylin-eosin staining were used to observe pathohistological changes. Tissue from RFM cows showed fibronecrosis of the chorionic villi, and a decreased number of trophoblastic cells. The majority of trophoblastic cells displayed vacuolar degeneration. Interstitium vessels were distended and congested. Expression of induced nitric oxide synthase (iNOS) protein and iNOS mRNA was significantly higher (P < 0.05) in the cytoplasm of placental villus trophoblastic cells in the RFM group. But expression of endothelial nitric oxide synthase (eNOS) protein and eNOS mRNA was significantly lower (P<0.05) in the RFM group. The NO content and NOS activity of cows with RFM were significantly higher (P < 0.05). A high expression of iNOS protein and iNOS mRNA in the cow foetal placenta could produce high content of NO, which might inhibit uterine contraction. So over expression of iNOS protein and iNOS mRNA might be an important agent of retained fetal membranes in cows, and it may be a potential diagnosis biomarker. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Geranyl diphosphate synthase from mint

    DOEpatents

    Croteau, Rodney Bruce; Wildung, Mark Raymond; Burke, Charles Cullen; Gershenzon, Jonathan

    1999-01-01

    A cDNA encoding geranyl diphosphate synthase from peppermint has been isolated and sequenced, and the corresponding amino acid sequence has been determined. Accordingly, an isolated DNA sequence (SEQ ID No:1) is provided which codes for the expression of geranyl diphosphate synthase (SEQ ID No:2) from peppermint (Mentha piperita). In other aspects, replicable recombinant cloning vehicles are provided which code for geranyl diphosphate synthase or for a base sequence sufficiently complementary to at least a portion of the geranyl diphosphate synthase DNA or RNA to enable hybridization therewith (e.g., antisense geranyl diphosphate synthase RNA or fragments of complementary geranyl diphosphate synthase DNA which are useful as polymerase chain reaction primers or as probes for geranyl diphosphate synthase or related genes). In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding geranyl diphosphate synthase. Thus, systems and methods are provided for the recombinant expression of geranyl diphosphate synthase that may be used to facilitate the production, isolation and purification of significant quantities of recombinant geranyl diphosphate synthase for subsequent use, to obtain expression or enhanced expression of geranyl diphosphate synthase in plants in order to enhance the production of monoterpenoids, to produce geranyl diphosphate in cancerous cells as a precursor to monoterpenoids having anti-cancer properties or may be otherwise employed for the regulation or expression of geranyl diphosphate synthase or the production of geranyl diphosphate.

  16. 24-hour urinary aldosterone excretion test

    MedlinePlus

    Aldosterone - urine; Addison disease - urine aldosterone; Cirrhosis - serum aldosterone ... A 24-hour urine sample is needed. You will need to collect your urine over 24 hours . Your health care provider will tell ...

  17. Bimodal Aldosterone Distribution in Low-Renin Hypertension

    PubMed Central

    2013-01-01

    BACKGROUND In low-renin hypertension (LRH), serum aldosterone levels are higher in those subjects with primary aldosteronism and may be lower in those with non-aldosterone mineralocorticoid excess or primary renal sodium retention. We investigated the hypothesis that the frequency distribution of aldosterone in LRH is bimodal. METHODS Of the 3,532 attendees at the sixth examination cycle of the Framingham Offspring Study, 1,831 were included in this cross-sectional analysis after we excluded those with conditions or taking medications such as antihypertensive drugs that might affect renin or aldosterone. RESULTS Three hundred three subjects (17%) had untreated hypertension (SBP ≥140mm Hg or DBP ≥90mm Hg). LRH, defined as plasma renin ≤5 mU/L, was present in 93 of those 303 hypertensive subjects (31%). Aldosterone values were adjusted statistically for age, sex, and the urinary sodium/creatinine ratio. In the subjects with LRH, the adjusted aldosterone distribution was bimodal (dip test for unimodality, P = 0.008). The adjusted aldosterone distribution was unimodal in the normal subjects (P = 0.98) and in the hypertensive subjects with normal plasma renin (P = 0.94). CONCLUSIONS In this community-based sample of white subjects, those with low-renin hypertension had a bimodal adjusted aldosterone distribution. Subjects with normal-renin hypertension and subjects with normal blood pressure had unimodal adjusted aldosterone distributions. These findings suggest 2 pathophysiological variants of LRH, one that is aldosterone-dependent and one that is non-aldosterone-dependent. PMID:23757402

  18. Aldosterone to Renin Ratio as a Screening Instrument for Primary Aldosteronism in a Middle-Aged Population with Atrial Fibrillation.

    PubMed

    Mourtzinis, Georgios; Ebrahimi, Ahmad; Gustafsson, Helena; Johannsson, Gudmundur; Manhem, Karin

    2017-11-01

    Atrial fibrillation seems to be overrepresented among patients with primary aldosteronism. The aim of this study was to determine the usefulness of aldosterone to renin ratio as a screening instrument for primary aldosteronism in an atrial fibrillation population with relatively low cardiovascular risk profile. A total of 149 patients <65 years and with history of AF were screened for primary aldosteronism using aldosterone to renin ratio. Pathologically increased aldosterone to renin ratio (>65 pmol/mIU) was found in 15 participants (10.1%). Further investigation of the positive screened participants and confirmatory saline infusion test resulted in a diagnosis of primary aldosteronism in four individuals out of 149 (2.6%). Three out of the four individuals with primary aldosteronism had previously been diagnosed with hypertension, but only one out of the four had uncontrolled blood pressure, that is, >140/90 mmHg. All participants had normal potassium levels. Individuals with increased aldosterone to renin ratio had significantly higher mean systolic and diastolic blood pressure in comparison to participants with normal aldosterone to renin ratio (136 vs. 126 mmHg, p=0.02 and 84 vs. 78 mmHg, p=0.02). These findings suggest that assessment of aldosterone to renin ratio can be useful for identification of underlying primary aldosteronism in patients with diagnosed atrial fibrillation and hypertension in spite of well controlled blood pressure and normokalemia. © Georg Thieme Verlag KG Stuttgart · New York.

  19. Aldosterone modulates thiazide-sensitive sodium chloride cotransporter abundance via DUSP6-mediated ERK1/2 signaling pathway.

    PubMed

    Feng, Xiuyan; Zhang, Yiqian; Shao, Ningjun; Wang, Yanhui; Zhuang, Zhizhi; Wu, Ping; Lee, Matthew J; Liu, Yingli; Wang, Xiaonan; Zhuang, Jieqiu; Delpire, Eric; Gu, Dingying; Cai, Hui

    2015-05-15

    Thiazide-sensitive sodium chloride cotransporter (NCC) plays an important role in maintaining blood pressure. Aldosterone is known to modulate NCC abundance. Previous studies reported that dietary salts modulated NCC abundance through either WNK4 [with no lysine (k) kinase 4]-SPAK (Ste20-related proline alanine-rich kinase) or WNK4-extracellular signal-regulated kinase-1 and -2 (ERK1/2) signaling pathways. To exclude the influence of SPAK signaling pathway on the role of the aldosterone-mediated ERK1/2 pathway in NCC regulation, we investigated the effects of dietary salt changes and aldosterone on NCC abundance in SPAK knockout (KO) mice. We found that in SPAK KO mice low-salt diet significantly increased total NCC abundance while reducing ERK1/2 phosphorylation, whereas high-salt diet decreased total NCC while increasing ERK1/2 phosphorylation. Importantly, exogenous aldosterone administration increased total NCC abundance in SPAK KO mice while increasing DUSP6 expression, an ERK1/2-specific phosphatase, and led to decreasing ERK1/2 phosphorylation without changing the ratio of phospho-T53-NCC/total NCC. In mouse distal convoluted tubule (mDCT) cells, aldosterone increased DUSP6 expression while reducing ERK1/2 phosphorylation. DUSP6 Knockdown increased ERK1/2 phosphorylation while reducing total NCC expression. Inhibition of DUSP6 by (E)-2-benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one increased ERK1/2 phosphorylation and reversed the aldosterone-mediated increments of NCC partly by increasing NCC ubiquitination. Therefore, these data suggest that aldosterone modulates NCC abundance via altering NCC ubiquitination through a DUSP6-dependent ERK1/2 signal pathway in SPAK KO mice and part of the effects of dietary salt changes may be mediated by aldosterone in the DCTs.

  20. Aldosterone modulates thiazide-sensitive sodium chloride cotransporter abundance via DUSP6-mediated ERK1/2 signaling pathway

    PubMed Central

    Feng, Xiuyan; Zhang, Yiqian; Shao, Ningjun; Wang, Yanhui; Zhuang, Zhizhi; Wu, Ping; Lee, Matthew J.; Liu, Yingli; Wang, Xiaonan; Zhuang, Jieqiu; Delpire, Eric; Gu, Dingying

    2015-01-01

    Thiazide-sensitive sodium chloride cotransporter (NCC) plays an important role in maintaining blood pressure. Aldosterone is known to modulate NCC abundance. Previous studies reported that dietary salts modulated NCC abundance through either WNK4 [with no lysine (k) kinase 4]-SPAK (Ste20-related proline alanine-rich kinase) or WNK4-extracellular signal-regulated kinase-1 and -2 (ERK1/2) signaling pathways. To exclude the influence of SPAK signaling pathway on the role of the aldosterone-mediated ERK1/2 pathway in NCC regulation, we investigated the effects of dietary salt changes and aldosterone on NCC abundance in SPAK knockout (KO) mice. We found that in SPAK KO mice low-salt diet significantly increased total NCC abundance while reducing ERK1/2 phosphorylation, whereas high-salt diet decreased total NCC while increasing ERK1/2 phosphorylation. Importantly, exogenous aldosterone administration increased total NCC abundance in SPAK KO mice while increasing DUSP6 expression, an ERK1/2-specific phosphatase, and led to decreasing ERK1/2 phosphorylation without changing the ratio of phospho-T53-NCC/total NCC. In mouse distal convoluted tubule (mDCT) cells, aldosterone increased DUSP6 expression while reducing ERK1/2 phosphorylation. DUSP6 Knockdown increased ERK1/2 phosphorylation while reducing total NCC expression. Inhibition of DUSP6 by (E)-2-benzylidene-3-(cyclohexylamino)-2,3-dihydro-1H-inden-1-one increased ERK1/2 phosphorylation and reversed the aldosterone-mediated increments of NCC partly by increasing NCC ubiquitination. Therefore, these data suggest that aldosterone modulates NCC abundance via altering NCC ubiquitination through a DUSP6-dependent ERK1/2 signal pathway in SPAK KO mice and part of the effects of dietary salt changes may be mediated by aldosterone in the DCTs. PMID:25761881

  1. Geranyl diphosphate synthase from mint

    DOEpatents

    Croteau, R.B.; Wildung, M.R.; Burke, C.C.; Gershenzon, J.

    1999-03-02

    A cDNA encoding geranyl diphosphate synthase from peppermint has been isolated and sequenced, and the corresponding amino acid sequence has been determined. Accordingly, an isolated DNA sequence (SEQ ID No:1) is provided which codes for the expression of geranyl diphosphate synthase (SEQ ID No:2) from peppermint (Mentha piperita). In other aspects, replicable recombinant cloning vehicles are provided which code for geranyl diphosphate synthase or for a base sequence sufficiently complementary to at least a portion of the geranyl diphosphate synthase DNA or RNA to enable hybridization therewith (e.g., antisense geranyl diphosphate synthase RNA or fragments of complementary geranyl diphosphate synthase DNA which are useful as polymerase chain reaction primers or as probes for geranyl diphosphate synthase or related genes). In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding geranyl diphosphate synthase. Thus, systems and methods are provided for the recombinant expression of geranyl diphosphate synthase that may be used to facilitate the production, isolation and purification of significant quantities of recombinant geranyl diphosphate synthase for subsequent use, to obtain expression or enhanced expression of geranyl diphosphate synthase in plants in order to enhance the production of monoterpenoids, to produce geranyl diphosphate in cancerous cells as a precursor to monoterpenoids having anti-cancer properties or may be otherwise employed for the regulation or expression of geranyl diphosphate synthase or the production of geranyl diphosphate. 5 figs.

  2. Therapeutic perspectives in hypertension: novel means for renin-angiotensin-aldosterone system modulation and emerging device-based approaches.

    PubMed

    Unger, Thomas; Paulis, Ludovit; Sica, Domenic A

    2011-11-01

    The conventional antihypertensive therapies including renin-angiotensin-aldosterone system antagonists (converting enzyme inhibitors, receptor blockers, renin inhibitors, and mineralocorticoid receptor blockers), diuretics, β-blockers, and calcium channel blockers are variably successful in achieving the challenging target blood pressure values in hypertensive patients. Difficult to treat hypertension is still a commonly observed problem world-wide. A number of drugs are considered to be used as novel therapies for hypertension. Renalase supplementation, vasopeptidase inhibitors, endothelin antagonists, and especially aldosterone antagonists (aldosterone synthase inhibitors and novel selective mineralocorticoid receptor blockers) are considered an option in resistant hypertension. In addition, the aldosterone antagonists as well as (pro)renin receptor blockers or AT(2) receptor agonists might attenuate end-organ damage. This array of medications has now been complemented by a number of new approaches of non-pharmacological strategies including vaccination, genomic interference, controlled breathing, baroreflex activation, and probably most successfully renal denervation techniques. However, the progress on innovative therapies seems to be slow and the problem of resistant hypertension and proper blood pressure control appears to be still persisting. Therefore the regimens of currently available drugs are being fine-tuned, resulting in the establishment of several novel fixed-dose combinations including triple combinations with the aim to facilitate proper blood pressure control. It remains an exciting question which approach will confer the best blood pressure control and risk reduction in this tricky disease.

  3. Therapeutic perspectives in hypertension: novel means for renin–angiotensin–aldosterone system modulation and emerging device-based approaches

    PubMed Central

    Unger, Thomas; Paulis, Ludovit; Sica, Domenic A.

    2011-01-01

    The conventional antihypertensive therapies including renin–angiotensin–aldosterone system antagonists (converting enzyme inhibitors, receptor blockers, renin inhibitors, and mineralocorticoid receptor blockers), diuretics, β-blockers, and calcium channel blockers are variably successful in achieving the challenging target blood pressure values in hypertensive patients. Difficult to treat hypertension is still a commonly observed problem world-wide. A number of drugs are considered to be used as novel therapies for hypertension. Renalase supplementation, vasopeptidase inhibitors, endothelin antagonists, and especially aldosterone antagonists (aldosterone synthase inhibitors and novel selective mineralocorticoid receptor blockers) are considered an option in resistant hypertension. In addition, the aldosterone antagonists as well as (pro)renin receptor blockers or AT2 receptor agonists might attenuate end-organ damage. This array of medications has now been complemented by a number of new approaches of non-pharmacological strategies including vaccination, genomic interference, controlled breathing, baroreflex activation, and probably most successfully renal denervation techniques. However, the progress on innovative therapies seems to be slow and the problem of resistant hypertension and proper blood pressure control appears to be still persisting. Therefore the regimens of currently available drugs are being fine-tuned, resulting in the establishment of several novel fixed-dose combinations including triple combinations with the aim to facilitate proper blood pressure control. It remains an exciting question which approach will confer the best blood pressure control and risk reduction in this tricky disease. PMID:21951628

  4. Vascular dysfunction and fibrosis in stroke-prone spontaneously hypertensive rats: The aldosterone-mineralocorticoid receptor-Nox1 axis.

    PubMed

    Harvey, Adam P; Montezano, Augusto C; Hood, Katie Y; Lopes, Rheure A; Rios, Francisco; Ceravolo, Graziela; Graham, Delyth; Touyz, Rhian M

    2017-06-15

    We questioned whether aldosterone and oxidative stress play a role in vascular damage in severe hypertension and investigated the role of Nox1 in this process. We studied mesenteric arteries, aortas and vascular smooth muscle cells (VSMC) from WKY and SHRSP rats. Vascular effects of eplerenone or canrenoic acid (CA) (mineralocorticoid receptor (MR) blockers), ML171 (Nox1 inhibitor) and EHT1864 (Rac1/2 inhibitor) were assessed. Nox1-knockout mice were also studied. Vessels and VSMCs were probed for Noxs, reactive oxygen species (ROS) and pro-fibrotic/inflammatory signaling. Blood pressure and plasma levels of aldosterone and galectin-3 were increased in SHRSP versus WKY. Acetylcholine-induced vasorelaxation was decreased (61% vs 115%) and phenylephrine-induced contraction increased in SHRSP versus WKY (E max 132.8% vs 96.9%, p<0.05). Eplerenone, ML171 and EHT1864 attenuated hypercontractility in SHRSP. Vascular expression of collagen, fibronectin, TGFβ, MCP-1, RANTES, MMP2, MMP9 and p66Shc was increased in SHRSP versus WKY. These changes were associated with increased ROS generation, 3-nitrotyrosine expression and Nox1 upregulation. Activation of vascular p66Shc and increased expression of Nox1 and collagen I were prevented by CA in SHRSP. Nox1 expression was increased in aldosterone-stimulated WKY VSMCs, an effect that was amplified in SHRSP VSMCs (5.2vs9.9 fold-increase). ML171 prevented aldosterone-induced VSMC Nox1-ROS production. Aldosterone increased vascular expression of fibronectin and PAI-1 in wild-type mice but not in Nox1-knockout mice. Our findings suggest that aldosterone, which is increased in SHRSP, induces vascular damage through MR-Nox1-p66Shc-mediated processes that modulate pro-fibrotic and pro-inflammatory signaling pathways. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Nedd4-2 Modulates Renal Na+-Cl− Cotransporter via the Aldosterone-SGK1-Nedd4-2 Pathway

    PubMed Central

    Arroyo, Juan Pablo; Lagnaz, Dagmara; Ronzaud, Caroline; Vázquez, Norma; Ko, Benjamin S.; Moddes, Lauren; Ruffieux-Daidié, Dorothée; Hausel, Pierrette; Koesters, Robert; Yang, Baoli; Stokes, John B.; Hoover, Robert S.

    2011-01-01

    Regulation of renal Na+ transport is essential for controlling blood pressure, as well as Na+ and K+ homeostasis. Aldosterone stimulates Na+ reabsorption by the Na+-Cl− cotransporter (NCC) in the distal convoluted tubule (DCT) and by the epithelial Na+ channel (ENaC) in the late DCT, connecting tubule, and collecting duct. Aldosterone increases ENaC expression by inhibiting the channel's ubiquitylation and degradation; aldosterone promotes serum-glucocorticoid-regulated kinase SGK1-mediated phosphorylation of the ubiquitin-protein ligase Nedd4-2 on serine 328, which prevents the Nedd4-2/ENaC interaction. It is important to note that aldosterone increases NCC protein expression by an unknown post-translational mechanism. Here, we present evidence that Nedd4-2 coimmunoprecipitated with NCC and stimulated NCC ubiquitylation at the surface of transfected HEK293 cells. In Xenopus laevis oocytes, coexpression of NCC with wild-type Nedd4-2, but not its catalytically inactive mutant, strongly decreased NCC activity and surface expression. SGK1 prevented this inhibition in a kinase-dependent manner. Furthermore, deficiency of Nedd4-2 in the renal tubules of mice and in cultured mDCT15 cells upregulated NCC. In contrast to ENaC, Nedd4-2-mediated inhibition of NCC did not require the PY-like motif of NCC. Moreover, the mutation of Nedd4-2 at either serine 328 or 222 did not affect SGK1 action, and mutation at both sites enhanced Nedd4-2 activity and abolished SGK1-dependent inhibition. Taken together, these results suggest that aldosterone modulates NCC protein expression via a pathway involving SGK1 and Nedd4-2 and provides an explanation for the well-known aldosterone-induced increase in NCC protein expression. PMID:21852580

  6. Monoterpene synthases from common sage (Salvia officinalis)

    DOEpatents

    Croteau, Rodney Bruce; Wise, Mitchell Lynn; Katahira, Eva Joy; Savage, Thomas Jonathan

    1999-01-01

    cDNAs encoding (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase from common sage (Salvia officinalis) have been isolated and sequenced, and the corresponding amino acid sequences has been determined. Accordingly, isolated DNA sequences (SEQ ID No:1; SEQ ID No:3 and SEQ ID No:5) are provided which code for the expression of (+)-bornyl diphosphate synthase (SEQ ID No:2), 1,8-cineole synthase (SEQ ID No:4) and (+)-sabinene synthase SEQ ID No:6), respectively, from sage (Salvia officinalis). In other aspects, replicable recombinant cloning vehicles are provided which code for (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase, or for a base sequence sufficiently complementary to at least a portion of (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase. Thus, systems and methods are provided for the recombinant expression of the aforementioned recombinant monoterpene synthases that may be used to facilitate their production, isolation and purification in significant amounts. Recombinant (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase may be used to obtain expression or enhanced expression of (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase in plants in order to enhance the production of monoterpenoids, or may be otherwise employed for the regulation or expression of (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase, or the production of their products.

  7. Aldosterone-Induced Vascular Remodeling and Endothelial Dysfunction Require Functional Angiotensin Type 1a Receptors.

    PubMed

    Briet, Marie; Barhoumi, Tlili; Mian, Muhammad Oneeb Rehman; Coelho, Suellen C; Ouerd, Sofiane; Rautureau, Yohann; Coffman, Thomas M; Paradis, Pierre; Schiffrin, Ernesto L

    2016-05-01

    We investigated the role of angiotensin type 1a receptors (AGTR1a) in vascular injury induced by aldosterone activation of mineralocorticoid receptors in Agtr1a(-/-) and wild-type (WT) mice infused with aldosterone for 14 days while receiving 1% NaCl in drinking water. Aldosterone increased systolic blood pressure (BP) by ≈30 mm Hg in WT mice and ≈50 mm Hg in Agtr1a(-/-) mice. Aldosterone induced aortic and small artery remodeling, impaired endothelium-dependent relaxation in WT mice, and enhanced fibronectin and collagen deposition and vascular inflammation. None of these vascular effects were observed in Agtr1a(-/-) mice. Aldosterone effects were prevented by the AGTR1 antagonist losartan in WT mice. In contrast to aldosterone, norepinephrine caused similar BP increase and mesenteric artery remodeling in WT and Agtr1a(-/-) mice. Agtr1a(-/-) mice infused with aldosterone did not increase sodium excretion in response to a sodium chloride challenge, suggesting that sodium retention could contribute to the exaggerated BP rise induced by aldosterone. Agtr1a(-/-) mice had decreased mesenteric artery expression of the calcium-activated potassium channel Kcnmb1, which may enhance myogenic tone and together with sodium retention, exacerbate BP responses to aldosterone/salt in Agtr1a(-/-) mice. We conclude that although aldosterone activation of mineralocorticoid receptors raises BP more in Agtr1a(-/-) mice, AGTR1a is required for mineralocorticoid receptor stimulation to induce vascular remodeling and inflammation and endothelial dysfunction. © 2016 American Heart Association, Inc.

  8. ALDOSTERONE-INDUCED VASCULAR REMODELING AND ENDOTHELIAL DYSFUNCTION REQUIRE FUNCTIONAL ANGIOTENSIN TYPE 1a RECEPTORS

    PubMed Central

    Coelho, Suellen C.; Ouerd, Sofiane; Rautureau, Yohann; Coffman, Thomas M.; Paradis, Pierre; Schiffrin, Ernesto L.

    2016-01-01

    We investigated the role of angiotensin type 1a receptors (AGTR1a) in vascular injury induced by aldosterone activation of mineralocorticoid receptors (MR) in Agtr1a−/− and wild-type mice infused with aldosterone for 14 days while receiving 1% NaCl in drinking water. Aldosterone increased systolic blood pressure by ~30 mmHg in wild-type mice, and ~50 mmHg in Agtr1a−/− mice. Aldosterone induced aortic and small artery remodeling and impaired endothelium-dependent relaxation in wild-type mice, and enhanced fibronectin and collagen deposition, and vascular inflammation. None of these vascular effects were observed in Agtr1a−/− mice. Aldosterone effects were prevented by the AGTR1 antagonist losartan in wild-type mice. In contrast to aldosterone, norepinephrine caused similar BP increase and mesenteric artery remodeling in wild-type and Agtr1a−/− mice. Agtr1a−/− mice infused with aldosterone did not increase sodium excretion in response to a sodium chloride challenge, suggesting sodium retention that could contribute to the exaggerated blood pressure rise induced by aldosterone. Agtr1a−/− mice had decreased mesenteric artery expression of the calcium-activated potassium channel Kcnmb1, which may enhance myogenic tone and together with sodium retention exacerbate BP responses to aldosterone/salt in Agtr1a−/− mice. We conclude that although aldosterone activation of MR raises BP more in Agtr1a−/− mice, AGTR1a is required for MR stimulation to induce vascular remodeling and inflammation, and endothelial dysfunction. PMID:27045029

  9. ABNORMAL ALDOSTERONE PHYSIOLOGY AND CARDIO-METABOLIC RISK FACTORS

    PubMed Central

    Vaidya, Anand; Underwood, Patricia C.; Hopkins, Paul N.; Jeunemaitre, Xavier; Ferri, Claudio; Williams, Gordon H.; Adler, Gail K.

    2013-01-01

    Abnormal aldosterone physiology has been implicated in the pathogenesis of cardio-metabolic diseases. Single aldosterone measurements capture only a limited range of aldosterone physiology. New methods of characterizing aldosterone physiology may provide a more comprehensive understanding of its relationship with cardio-metabolic disease. We evaluated whether novel indices of aldosterone responses to dietary sodium modulation, the Sodium-modulated Aldosterone Suppression-Stimulation Index (SASSI for serum and SAUSSI for urine), could predict cardio-metabolic risk factors. We performed cross-sectional analyses on 539 subjects studied on liberal (LIB) and restricted (RES) sodium diets with serum and urinary aldosterone measurements. SASSI and SAUSSI were calculated as the ratio of aldosterone on LIB (maximally suppressed aldosterone) to aldosterone on RES (stimulated aldosterone) diets, and associated with risk factors using adjusted regression models. Cardio-metabolic risk factors associated with either impaired suppression of aldosterone on LIB diet, or impaired stimulation on RES diet, or both; in all of these individual cases, these risk factors associated with higher SASSI or SAUSSI. In the context of abnormalities that comprise the metabolic syndrome (MetS), there was a strong positive association between the number of MetS components (0–4) and both SASSI and SAUSSI (P<0.0001) that was independent of known aldosterone secretagogues (angiotensin II, corticotropin, potassium). SASSI and SAUSSI exhibited a high sensitivity in detecting normal individuals with zero MetS components (86% for SASSI and 83% for SAUSSI). Assessing the physiologic range of aldosterone responses may provide greater insights into adrenal pathophysiology. Dysregulated aldosterone physiology may contribute to, and/or result from, early cardio-metabolic abnormalities. PMID:23399714

  10. Impact of drought stress on specialised metabolism: Biosynthesis and the expression of monoterpene synthases in sage (Salvia officinalis).

    PubMed

    Radwan, Alzahraa; Kleinwächter, Maik; Selmar, Dirk

    2017-09-01

    In previous experiments, we demonstrated that the amount of monoterpenes in sage is increased massively by drought stress. Our current study is aimed to elucidate whether this increase is due, at least in part, to elevated activity of the monoterpene synthases responsible for the biosynthesis of essential oils in sage. Accordingly, the transcription rates of the monoterpene synthases were analyzed. Salvia officinalis plants were cultivated under moderate drought stress. The concentrations of monoterpenes as well as the expression of the monoterpene synthases were analyzed. The amount of monoterpenes massively increased in response to drought stress; it doubled after just two days of drought stress. The observed changes in monoterpene content mostly match with the patterns of monoterpene synthase expressions. The expression of bornyl diphosphate synthase was strongly up-regulated; its maximum level was reached after two days. Sabinene synthase increased gradually and reached a maximum after two weeks. In contrast, the transcript level of cineole synthase continuously declined. This study revealed that the stress related increase of biosynthesis is not only due to a "passive" shift caused by the stress related over-reduced status, but also is due - at least in part-to an "active" up-regulation of the enzymes involved. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Effect of Swimming on the Production of Aldosterone in Rats

    PubMed Central

    Wang, Paulus S.; Jian, Cai-Yun; Yeh, Yung-Hsing; Chen, Yi-An; Wang, Kai-Lee; Lin, Yi-Chun; Chang, Ling-Ling; Wang, Guei-Jane; Wang, Shyi-Wu

    2014-01-01

    It has been demonstrated that exercise is one of the stresses known to increase the aldosterone secretion. Both potassium and angiotensin II (Ang II) levels are shown to be correlated with aldosterone production during exercise, but the mechanism is still unclear. In an in vivo study, male rats were catheterized via right jugular vein (RJV), and divided into four groups namely water immersion, swimming, lactate infusion (13 mg/kg/min) and pyruvate infusion (13 mg/kg/min) groups. Each group was treated for 10 min. Blood samples were collected at 0, 10, 15, 30, 60 and 120 min from RJV after administration. In an in vitro study, rat zona glomerulosa (ZG) cells were challenged by lactate (1–10 mM) in the presence or absence of Ang II (10−8 M) for 60 min. The levels of aldosterone in plasma and medium were measured by radioimmunoassay. Cell lysates were analyzed by immunoblotting assay. After exercise and lactate infusion, plasma levels of aldosterone and lactate were significantly higher than those in the control group. Swimming for 10 min significantly increased the plasma Ang II levels in male rats. Administration of lactate plus Ang II significantly increased aldosterone production and enhanced protein expression of steroidogenic acute regulatory protein (StAR) in ZG cells. These results demonstrated that acute exercise led to the increase of both aldosterone and Ang II secretion, which is associated with lactate action on ZG cells and might be dependent on the activity of renin-angiotensin system. PMID:25289701

  12. Identification of novel isoprene synthases through genome mining and expression in Escherichia coli.

    PubMed

    Ilmén, Marja; Oja, Merja; Huuskonen, Anne; Lee, Sangmin; Ruohonen, Laura; Jung, Simon

    2015-09-01

    Isoprene is a naturally produced hydrocarbon emitted into the atmosphere by green plants. It is also a constituent of synthetic rubber and a potential biofuel. Microbial production of isoprene can become a sustainable alternative to the prevailing chemical production of isoprene from petroleum. In this work, sequence homology searches were conducted to find novel isoprene synthases. Candidate sequences were functionally expressed in Escherichia coli and the desired enzymes were identified based on an isoprene production assay. The activity of three enzymes was shown for the first time: expression of the candidate genes from Ipomoea batatas, Mangifera indica, and Elaeocarpus photiniifolius resulted in isoprene formation. The Ipomoea batatas isoprene synthase produced the highest amounts of isoprene in all experiments, exceeding the isoprene levels obtained by the previously known Populus alba and Pueraria montana isoprene synthases that were studied in parallel as controls. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  13. Albuminuria is associated with an increased prostasin in urine while aldosterone has no direct effect on urine and kidney tissue abundance of prostasin.

    PubMed

    Oxlund, Christina; Kurt, Birgül; Schwarzensteiner, Ilona; Hansen, Mie R; Stæhr, Mette; Svenningsen, Per; Jacobsen, Ib A; Hansen, Pernille B; Thuesen, Anne D; Toft, Anja; Hinrichs, Gitte R; Bistrup, Claus; Jensen, Boye L

    2017-06-01

    The proteinase prostasin is a candidate mediator for aldosterone-driven proteolytic activation of the epithelial sodium channel (ENaC). It was hypothesized that the aldosterone-mineralocorticoid receptor (MR) pathway stimulates prostasin abundance in kidney and urine. Prostasin was measured in plasma and urine from type 2 diabetic patients with resistant hypertension (n = 112) randomized to spironolactone/placebo in a clinical trial. Prostasin protein level was assessed by immunoblotting in (1) human and rat urines with/without nephrotic syndrome, (2) human nephrectomy tissue, (3) urine and kidney from aldosterone synthase-deficient (AS -/- ) mice and ANGII- and aldosterone-infused mice, and in (4) kidney from adrenalectomized rats. Serum aldosterone concentration related to prostasin concentration in urine but not in plasma. Plasma prostasin concentration increased significantly after spironolactone compared to control. Urinary prostasin and albumin related directly and were reduced by spironolactone. In patients with nephrotic syndrome, urinary prostasin protein was elevated compared to controls. In rat nephrosis, proteinuria coincided with increased urinary prostasin, unchanged kidney tissue prostasin, and decreased plasma prostasin while plasma aldosterone was suppressed. Prostasin protein abundance in human nephrectomy tissue was similar across gender and ANGII inhibition regimens. Prostasin urine abundance was not different in AS -/- and aldosterone-infused mice. Prostasin kidney level was not different from control in adrenalectomized rats and AS -/- mice. We found no evidence for a direct relationship between mineralocorticoid receptor signaling and kidney and urine prostasin abundance. The reduction of urinary prostasin in spironolactone-treated patients is most likely the result of an improved glomerular filtration barrier function and generally reduced proteinuria.

  14. Screening for primary aldosteronism--normal ranges for aldosterone and renin in three South African population groups.

    PubMed

    Rayner, B L; Myers, J E; Opie, L H; Trinder, Y A; Davidson, J S

    2001-07-01

    To establish normal ranges for plasma aldosterone, renin and aldosterone/renin (A/R) ratio in South African normotensives under typical outpatient conditions, and to estimate the prevalence of primary aldosteronism (PA) among hypertensives in primary care settings. One hundred and thirty-six normotensive subjects and 154 sex- and age-matched hypertensives at three primary care clinics had measurements of blood pressure, plasma creatinine, K+, aldosterone, plasma renin activity, and spot urine for urinary Na+/creatinine ratio. Medication was not withdrawn before testing. Mean plasma renin activity in black normotensive subjects (0.95 +/- 1.25 ng/ml/h, mean +/- standard deviation (SD)) was significantly lower than in white (2.09 +/- 1.12 ng/ml/h; P < 0.0001) and coloured (1.81 +/- 1.86 ng/ml/h, P = 0.013) normotensives. Mean plasma aldosterone in black normotensives (306 +/- 147 pmol/l) was also significantly lower than in white (506 +/- 324 pmol/l, P = 0.0002) and coloured (418 +/- 304 pmol/l, P = 0.0148) normotensives. In hypertensives, there were no significant differences in renin or aldosterone levels between the three population groups. Urinary Na+/creatinine ratios, an index of Na+ intake, were not significantly different in the three population groups. None of the normotensives had an A/R ratio > or = 1,000 plus aldosterone > or = 750, while 7.1% of hypertensives exceeded these levels, suggesting that they are appropriate criteria for screening for PA. A large fraction of black normotensive subjects had low renin and aldosterone levels compared with whites, suggesting a salt-retaining tendency in black subjects. These results have important implications for the interpretation of plasma renin and aldosterone levels in hypertensive patients. In primary care settings, 7.1% of hypertensives had biochemical results indicating the need for investigation of PA.

  15. Endocrine and Hypertensive Disorders of Potassium Regulation: Primary Aldosteronism

    PubMed Central

    Weiner, I. David

    2013-01-01

    The identification that primary aldosteronism is a common cause of resistant hypertension is a significant advance in our ability to care for patients with hypertension. Primary aldosteronism is common, and when unrecognized is associated with increased incidence of adverse cardiovascular outcomes. Identification of primary aldosteronism is based upon use of the plasma aldosterone level, plasma renin activity and the aldosterone:renin ratio (ARR). Differentiation between unilateral and bilateral autonomous adrenal aldosterone production then guides further therapy, with use of mineralocorticoid receptor blockers for those with bilateral autonomous adrenal aldosterone production and laparoscopic adrenalectomy for those with unilateral autonomous aldosterone production. In this review, we discuss in detail the pathogenesis of primary aldosteronism-induced hypertension and potassium disorders, the evaluation of the patient with suspected primary aldosteronism and the management of primary aldosteronism, both through medications and through surgery. PMID:23953804

  16. Effect of Combined Stress on Morphological Changes and Expression of NO Synthases in Rat Ventral Hippocampus.

    PubMed

    Smirnov, A V; Tyurenkov, I N; Shmidt, M V; Ekova, M R; Mednikov, D S; Borodin, D D

    2015-11-01

    Adult rats were subjected to 7-day combined stress with stochastic changes of stressors of different modalities (noise, vibration, pulsating bright light) along with mobility restriction and elevated temperature in the chamber during stress exposures (daily 30-min sessions). Circulatory disorders, inhibition of endothelial NO-synthase expression in endothelial cells of the microcirculatory bed, perivascular edema, pronounced degenerative changes, and enhanced expression of inducible NO synthase in CA3 pyramidal neurons in the ventral hippocampus of stressed 12-month-old rats were observed. These findings can attest to the involvement NOdependent mechanisms and different contribution of NO synthase isoforms into the formation of hippocampal neuronal damage.

  17. Obesity-stimulated aldosterone release is not related to an S1P-dependent mechanism.

    PubMed

    Werth, Stephan; Müller-Fielitz, Helge; Raasch, Walter

    2017-12-01

    Aldosterone has been identified as an important factor in obesity-associated hypertension. Here, we investigated whether sphingosine-1-phosphate (S1P), which has previously been linked to obesity, increases aldosterone release. S1P-induced aldosterone release was determined in NCI H295R cells in the presence of S1P receptor (S1PR) antagonists. In vivo release of S1P (100-300 µg/kg bw ) was investigated in pithed, lean Sprague Dawley (SD) rats, diet-obese spontaneous hypertensive rats (SHRs), as well as in lean or obese Zucker rats. Aldosterone secretion was increased in NCI H295R cells by S1P, the selective S1PR1 agonist SEW2871 and the selective S1PR2 antagonist JTE013. Treatment with the S1PR1 antagonist W146 or fingolimod and the S1PR1/3 antagonist VPbib2319 decreased baseline and/or S1P-stimulated aldosterone release. Compared to saline-treated SD rats, plasma aldosterone increased by ~50 pg/mL after infusing S1P. Baseline levels of S1P and aldosterone were higher in obese than in lean SHRs. Adrenal S1PR expression did not differ between chow- or CD-fed rats that had the highest S1PR1 and lowest S1PR4 levels. S1P induced a short-lasting increase in plasma aldosterone in obese, but not in lean SHRs. However, 2-ANOVA did not demonstrate any difference between lean and obese rats. S1P-induced aldosterone release was also similar between obese and lean Zucker rats. We conclude that S1P is a local regulator of aldosterone production. S1PR1 agonism induces an increase in aldosterone secretion, while stimulating adrenal S1PR2 receptor suppresses aldosterone production. A significant role of S1P in influencing aldosterone secretion in states of obesity seems unlikely. © 2017 Society for Endocrinology.

  18. Impact of aldosterone antagonists on the substrate for atrial fibrillation: Aldosterone promotes oxidative stress and atrial structural/electrical remodeling

    PubMed Central

    Mayyas, Fadia; Alzoubi, Karem H.; Van Wagoner, David R.

    2014-01-01

    Atrial fibrillation (AF), the most common cardiac arrhythmia, is an electrocardiographic description of a condition with multiple and complex underlying mechanisms. Oxidative stress is an important driver of structural remodeling that creates a substrate for AF. Oxidant radicals may promote increase of atrial oxidative damage, electrical and structural remodeling, and atrial inflammation. AF and other cardiovascular morbidities activate angiotensin (Ang-II)-dependent and independent cascades. A key component of the renin–angiotensin-aldosterone system (RAAS) is the mineralocorticoid aldosterone. Recent studies provide evidence of myocardial aldosterone synthesis. Aldosterone promotes cardiac oxidative stress, inflammation and structural/electrical remodeling via multiple mechanisms. In HF patients, aldosterone production is enhanced. In patients and in experimental HF and AF models, aldosterone receptor antagonists have favorable influences on cardiac remodeling and oxidative stress. Therapeutic approaches that seek to reduce AF burden by modulating the aldosterone system are likely beneficial but underutilized. PMID:23993726

  19. The Potassium Channel, Kir3.4 Participates in Angiotensin II-Stimulated Aldosterone Production by a Human Adrenocortical Cell Line

    PubMed Central

    Oki, Kenji; Plonczynski, Maria W.; Lam, Milay Luis; Gomez-Sanchez, Elise P.

    2012-01-01

    Angiotensin II (A-II) regulation of aldosterone secretion is initiated by inducing cell membrane depolarization, thereby increasing intracellular calcium and activating the calcium calmodulin/calmodulin kinase cascade. Mutations in the selectivity filter of the KCNJ5 gene coding for inward rectifying potassium channel (Kir)3.4 has been found in about one third of aldosterone-producing adenomas. These mutations result in loss of selectivity of the inward rectifying current for potassium, which causes membrane depolarization and opening of calcium channels and activation of the calcium calmodulin/calmodulin kinase cascade and results in an increase in aldosterone secretion. In this study we show that A-II and a calcium ionophore down-regulate the expression of KCNJ5 mRNA and protein. Activation of Kir3.4 by naringin inhibits A-II-stimulated membrane voltage and aldosterone secretion. Overexpression of KCNJ5 in the HAC15 cells using a lentivirus resulted in a decrease in membrane voltage, intracellular calcium, expression of steroidogenic acute regulatory protein, 3-β-hydroxysteroid dehydrogenase 3B2, cytochrome P450 11B1 and cytochrome P450 11B2 mRNA, and aldosterone synthesis. In conclusion, A-II appears to stimulate aldosterone secretion by depolarizing the membrane acting in part through the regulation of the expression and activity of Kir3.4. PMID:22798349

  20. Identification of a novel CoA synthase isoform, which is primarily expressed in Brain

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nemazanyy, Ivan; Panasyuk, Ganna; Breus, Oksana

    2006-03-24

    CoA and its derivatives Acetyl-CoA and Acyl-CoA are important players in cellular metabolism and signal transduction. CoA synthase is a bifunctional enzyme which mediates the final stages of CoA biosynthesis. In previous studies, we have reported molecular cloning, biochemical characterization, and subcellular localization of CoA synthase (CoASy). Here, we describe the existence of a novel CoA synthase isoform, which is the product of alternative splicing and possesses a 29aa extension at the N-terminus. We termed it CoASy {beta} and originally identified CoA synthase, CoASy {alpha}. The transcript specific for CoASy {beta} was identified by electronic screening and by RT-PCR analysismore » of various rat tissues. The existence of this novel isoform was further confirmed by immunoblot analysis with antibodies directed to the N-terminal peptide of CoASy {beta}. In contrast to CoASy {alpha}, which shows ubiquitous expression, CoASy {beta} is primarily expressed in Brain. Using confocal microscopy, we demonstrated that both isoforms are localized on mitochondria. The N-terminal extension does not affect the activity of CoA synthase, but possesses a proline-rich sequence which can bring the enzyme into complexes with signalling proteins containing SH3 or WW domains. The role of this novel isoform in CoA biosynthesis, especially in Brain, requires further elucidation.« less

  1. The Aldosterone Renin Ratio (ARR) APP as Tool to Enhance the Detection Rate of Primary Aldosteronism.

    PubMed

    Rossi, Gian Paolo; Bisogni, Valeria

    2016-06-01

    Primary aldosteronism is one of the most common forms of secondary hypertension, but it is often under diagnosed, which leads to the development of cardiovascular damage, and excess costs for long-term drug treatment and management of complications. The aldosterone to renin ratio (ARR) is a key step for early detection of primary aldosteronism, but unfortunately is not easily estimated. This is because plasma aldosterone and renin are measured with different assays, which provide results in different units of measure, with ensuing difficulty of obtaining the calculation of the ARR in the proper units and impossibility of interpreting results with reference to established cut off values. Therefore, doctors are often unable to draw unambiguous conclusions to be used for the clinical decision-making. To the aim of making the diagnostic work-up easier, we have developed an Application that provide a swift calculation of the ARR regardless of the units of measure used for plasma aldosterone and renin values. If the concomitant serum potassium level is available the App also provides the patient's probability of having an aldosterone-producing adenoma based on a validated logistic discriminant analysis.

  2. Long-term treatment with aldosterone slows the progression of age-related hearing loss.

    PubMed

    Halonen, Joshua; Hinton, Ashley S; Frisina, Robert D; Ding, Bo; Zhu, Xiaoxia; Walton, Joseph P

    2016-06-01

    Age-related hearing loss (ARHL), clinically referred to as presbycusis, is one of the three most prevalent chronic medical conditions of our elderly, with the majority of persons over the age of 60 suffering from some degree of ARHL. The progressive loss of auditory sensitivity and perceptual capability results in significant declines in workplace productivity, quality of life, cognition and abilities to communicate effectively. Aldosterone is a mineralocorticoid hormone produced in the adrenal glands and plays a role in the maintenance of key ion pumps, including the Na-K(+)-Cl co-transporter 1 or NKCC1, which is involved in homeostatic maintenance of the endocochlear potential. Previously we reported that aldosterone (1 μM) increases NKCC1 protein expression in vitro and that this up-regulation of NKCC1 was not dose-dependent (dosing range from 1 nM to 100 μM). In the current study we measured behavioral and electrophysiological hearing function in middle-aged mice following long-term systemic treatment with aldosterone. We also confirmed that blood pressure remained stable during treatment and that NKCC1 protein expression was upregulated. Pre-pulse inhibition of the acoustic startle response was used as a functional measure of hearing, and the auditory brainstem response was used as an objective measure of peripheral sensitivity. Long-term treatment with aldosterone improved both behavioral and physiological measures of hearing (ABR thresholds). These results are the first to demonstrate a protective effect of aldosterone on age-related hearing loss and pave the way for translational drug development, using aldosterone as a key component to prevent or slow down the progression of ARHL. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Aldosterone Inhibits the Fetal Program and Increases Hypertrophy in the Heart of Hypertensive Mice

    PubMed Central

    Azibani, Feriel; Devaux, Yvan; Coutance, Guillaume; Schlossarek, Saskia; Polidano, Evelyne; Fazal, Loubina; Merval, Regine; Carrier, Lucie; Solal, Alain Cohen; Chatziantoniou, Christos; Launay, Jean-Marie; Samuel, Jane-Lise; Delcayre, Claude

    2012-01-01

    Background Arterial hypertension (AH) induces cardiac hypertrophy and reactivation of “fetal” gene expression. In rodent heart, alpha-Myosin Heavy Chain (MyHC) and its micro-RNA miR-208a regulate the expression of beta-MyHC and of its intronic miR-208b. However, the role of aldosterone in these processes remains unclear. Methodology/Principal Findings RT-PCR and western-blot were used to investigate the genes modulated by arterial hypertension and cardiac hyperaldosteronism. We developed a model of double-transgenic mice (AS-Ren) with cardiac hyperaldosteronism (AS mice) and systemic hypertension (Ren). AS-Ren mice had increased (x2) angiotensin II in plasma and increased (x2) aldosterone in heart. Ren and AS-Ren mice had a robust and similar hypertension (+70%) versus their controls. Anatomical data and echocardiography showed a worsening of cardiac hypertrophy (+41%) in AS-Ren mice (P<0.05 vs Ren). The increase of ANP (x 2.5; P<0.01) mRNA observed in Ren mice was blunted in AS-Ren mice. This non-induction of antitrophic natriuretic peptides may be involved in the higher trophic cardiac response in AS-Ren mice, as indicated by the markedly reduced cardiac hypertrophy in ANP-infused AS-Ren mice for one month. Besides, the AH-induced increase of ßMyHC and its intronic miRNA-208b was prevented in AS-Ren. The inhibition of miR 208a (−75%, p<0.001) in AS-Ren mice compared to AS was associated with increased Sox 6 mRNA (x 1.34; p<0.05), an inhibitor of ßMyHC transcription. Eplerenone prevented all aldosterone-dependent effects. Conclusions/Significance Our results indicate that increased aldosterone in heart inhibits the induction of atrial natriuretic peptide expression, via the mineralocorticoid receptor. This worsens cardiac hypertrophy without changing blood pressure. Moreover, this work reveals an original aldosterone-dependent inhibition of miR-208a in hypertension, resulting in the inhibition of β-myosin heavy chain expression through the induction of

  4. Plasma adrenocorticotropic hormone but not aldosterone is correlated with blood pressure in patients with aldosterone-producing adenomas.

    PubMed

    Kobayashi, Hiroki; Haketa, Akira; Takahiro, Ueno; Otsuka, Hiromasa; Tanaka, Sho; Hatanaka, Yoshinari; Ikeda, Yukihiro; Abe, Masanori; Fukuda, Noboru; Soma, Masayoshi

    2017-03-01

    Although plasma aldosterone concentration (PAC) varies depending on primary aldosteronism (PA) subtypes, patients with different subtypes may have similar blood pressure (BP). The authors hypothesized that hormones other than aldosterone might influence BP in PA patients. A total of 73 PA cases, including 30 cases of aldosterone-producing adenomas (APAs), 29 cases of bilateral hyperaldosteronism, and 24 control cases of essential hypertension were enrolled retrospectively. The authors examined the levels of aldosterone, cortisol, renin, and adrenocorticotropic hormone (ACTH) measured at 12 am, 6 am, 12 pm, and 6 pm and BP in the early morning (6 am to 7 am), late morning (9 am to 11 am), and early evening (5 pm to 7 pm). Results showed no statistically significant correlation between PAC and BP in the patients with PA; however, early and late morning systolic BP strongly correlated with ACTH at 6 am in patients with APA. These results suggest that hormones other than aldosterone, such as ACTH, may affect BP in patients with APA. ©2016 Wiley Periodicals, Inc.

  5. A Continuum of Renin-Independent Aldosteronism in Normotension

    PubMed Central

    Baudrand, Rene; Guarda, Francisco J.; Fardella, Carlos; Hundemer, Gregory; Brown, Jenifer; Williams, Gordon; Vaidya, Anand

    2017-01-01

    Primary aldosteronism (PA) is a severe form of autonomous aldosteronism. Milder forms of autonomous and renin-independent aldosteronism may be common, even in normotension. We characterized aldosterone secretion in 210 normotensives who had suppressed plasma renin activity (PRA<1.0 ng/mL/h), completed an oral sodium suppression test, received an infusion of angiotensin II (AngII), and had measurements of blood pressure (BP) and renal plasma flow (RPF). Continuous associations between urinary aldosterone excretion rate (AER), renin, and potassium handling were investigated. Severe autonomous aldosterone secretion that was consistent with confirmed PA was defined based on accepted criteria of an AER >12 mcg/24h with urinary sodium excretion >200 mmol/24h. Across the population, there were strong and significant associations between higher AER and higher urinary potassium excretion, higher AngII-stimulated aldosterone, and lower PRA, suggesting a continuum of renin-independent aldosteronism and mineralocorticoid receptor activity. Autonomous aldosterone secretion that fulfilled confirmatory criteria for PA was detected in 29 participants (14%). Normotensives with evidence suggestive of confirmed PA had higher 24h urinary AER (20.2±12.2 vs. 6.2±2.9 mcg/24h, P<0.001) as expected, but also higher AngII-stimulated aldosterone (12.4±8.6 vs. 6.6±4.3 ng/dL, P<0.001) and lower 24h urinary sodium-to-potassium excretion (2.69±0.65 vs. 3.69±1.50 mmol/mmol, P=0.001); however, there were no differences in age, aldosterone-to-renin ratio, BP, or RPF between the two groups. These findings indicate a continuum of renin-independent aldosteronism and mineralocorticoid receptor activity in normotension that ranges from subtle to overtly dysregulated and autonomous. Longitudinal studies are needed to determine whether this spectrum of autonomous aldosterone secretion contributes to hypertension and cardiovascular disease. PMID:28289182

  6. Quantitative Value of Aldosterone-Renin Ratio for Detection of Aldosterone-Producing Adenoma: The Aldosterone-Renin Ratio for Primary Aldosteronism (AQUARR) Study.

    PubMed

    Maiolino, Giuseppe; Rossitto, Giacomo; Bisogni, Valeria; Cesari, Maurizio; Seccia, Teresa Maria; Plebani, Mario; Rossi, Gian Paolo

    2017-05-21

    Current guidelines recommend use of the aldosterone-renin ratio (ARR) for the case detection of primary aldosteronism followed by confirmatory tests to exclude false-positive results from further diagnostic workup. We investigated the hypothesis that this could be unnecessary in patients with a high ARR value if the quantitative information carried by the ARR is taken into due consideration. We interrogated 2 large data sets of prospectively collected patients studied with the same predefined protocol, which included the captopril challenge test. We used an unambiguous diagnosis of aldosterone-producing adenoma as reference index. We also assessed whether the post-captopril ARR and plasma aldosterone concentration fall furnished a diagnostic gain over baseline ARR values. We found that the false-positive rate fell exponentially, and, conversely, the specificity increased with rising ARR values. At receiver operating characteristics curves and diagnostic odds ratio analysis, the high baseline ARR values implied very high positive likelihood ratio and diagnostic odds ratio values. The baseline and post-captopril ARR showed similar diagnostic accuracy (area under the receiver operating characteristics curve) in both the exploratory and validation cohorts, indicating lack of diagnostic gain with this confirmatory test (between-area under the curve difference, 0.005; 95% CI, -0.031 to 0.040; P =0.7 for comparison, and 0.05; 95% CI, -0.061 to 0.064; P =0.051 for comparison, respectively). These results indicate that the ARR conveys key quantitative information that, if properly used, can simplify the diagnostic workup, resulting in saving of money and resources. This can offer the chance of diagnosis and ensuing adrenalectomy to a larger number of hypertensive patients, ultimately resulting in better control of blood pressure. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

  7. Iron restriction inhibits renal injury in aldosterone/salt-induced hypertensive mice.

    PubMed

    Sawada, Hisashi; Naito, Yoshiro; Oboshi, Makiko; Iwasaku, Toshihiro; Okuhara, Yoshitaka; Morisawa, Daisuke; Eguchi, Akiyo; Hirotani, Shinichi; Masuyama, Tohru

    2015-05-01

    Excess iron is associated with the pathogenesis of several renal diseases. Aldosterone is reported to have deleterious effects on the kidney, but there have been no reports of the role of iron in aldosterone/salt-induced renal injury. Therefore, we investigated the effects of dietary iron restriction on the development of hypertension and renal injury in aldosterone/salt-induced hypertensive mice. Ten-week-old male C57BL/6J mice were uninephrectomized and infused with aldosterone for four weeks. These were divided into two groups: one fed a high-salt diet (Aldo) and the other fed a high-salt with iron-restricted diet (Aldo-IR). Vehicle-infused mice without a uninephrectomy were also divided into two groups: one fed a normal diet (control) and the other fed an iron-restricted diet (IR) for 4 weeks. As compared with control and IR mice, Aldo mice showed an increase in both systolic blood pressure and urinary albumin/creatinine ratio, but these increases were reduced in the Aldo-IR group. In addition, renal histology revealed that Aldo mice exhibited glomerulosclerosis and tubulointerstitial fibrosis, whereas these changes were attenuated in Aldo-IR mice. Expression of intracellular iron transport protein transferrin receptor 1 was increased in the renal tubules of Aldo mice compared with control mice. Dietary iron restriction attenuated the development of hypertension and renal injury in aldosterone/salt-induced hypertensive mice.

  8. Intracellular calcium: a prerequisite for aldosterone action.

    PubMed

    Schäfer, C; Shahin, V; Albermann, L; Schillers, H; Hug, M J; Oberleithner, H

    2003-12-01

    Transport of salt and water in various tissues is under control of the mineralocorticoid hormone aldosterone. As a liphophilic hormone, aldosterone diffuses through the plasma membrane and, then, binds to cytosolic mineralocorticoid receptors in the target cells. After binding to nuclear pore complexes, the activated receptor is translocated to the nucleus where transcription processes are initiated. After a lag period of about 20 minutes hormone-specific early mRNA transcripts leave the nucleus through nuclear pores. Some of the steps in this cascade can be followed by electrophysiology in Xenopus laevis oocyte nuclei. In addition to the genomic pathway, aldosterone exerts a rapid pre-genomic response that involves an increase in intracellular calcium. In this study, we tested for the potential role of Ca(2+) in the genomic response of the hormone. We measured the electrical resistance across the nuclear envelope in response to aldosterone, in presence and absence of intracellular Ca(2+). Nuclear envelope electrical resistance reflects receptor binding to the nuclear pore complexes ("early" resistance peak, 2 minutes after aldosterone), ongoing transcription ("transient" resistance drop, 5-15 minutes after aldosterone) and mRNA export ("late" resistance peak, 20 minutes after aldosterone). Pre-injection of the Ca(2+) chelator EGTA eliminated all electrical responses evoked by aldosterone. The transient resistance drop and the late resistance peak, induced by the hormone, were prevented by the transcription inhibitor actinomycin D, coinjected with aldosterone, while the early resistance peak remained unaffected. We conclude that (i). the presence of intracellular Ca(2+) is a prerequisite for the genomic action of aldosterone. (ii). Intracellular calcium plays a role early in the signaling cascade, either in agonist-receptor interaction, or receptor transport/docking to the nuclear pore complexes.

  9. Overexpressed cyclophilin B suppresses aldosterone-induced proximal tubular cell injury both in vitro and in vivo.

    PubMed

    Wang, Bin; Lin, Lilu; Wang, Haidong; Guo, Honglei; Gu, Yong; Ding, Wei

    2016-10-25

    The renin-angiotensin-aldosterone system (RAAS) is overactivated in patients with chronic kidney disease. Oxidative stress and endoplasmic reticulum stress (ERS) are two major mechanisms responsible for aldosterone-induced kidney injury. Cyclophilin (CYP) B is a chaperone protein that accelerates the rate of protein folding through its peptidyl-prolyl cis-trans isomerase (PPIase) activity. We report that overexpression of wild-type CYPB attenuated aldosterone-induced oxidative stress (evidenced by reduced production of reactive oxygen species and improved mitochondrial dysfunction), ERS (indicated by reduced expression of the ERS markers glucose-regulated protein 78 [GRP78] and C/-EBP homologous protein [CHOP]), and tubular cell apoptosis in comparison with aldosterone-induced human kidney-2 (HK-2) cells. The in vivo study also yielded similar results. Hence, CYPB performs a crucial function in protecting cells against aldosterone-induced oxidative stress, ERS, and tubular cell injury via its PPIase activity.

  10. Overexpressed cyclophilin B suppresses aldosterone-induced proximal tubular cell injury both in vitro and in vivo

    PubMed Central

    Wang, Haidong; Guo, Honglei; Gu, Yong; Ding, Wei

    2016-01-01

    The renin-angiotensin-aldosterone system (RAAS) is overactivated in patients with chronic kidney disease. Oxidative stress and endoplasmic reticulum stress (ERS) are two major mechanisms responsible for aldosterone-induced kidney injury. Cyclophilin (CYP) B is a chaperone protein that accelerates the rate of protein folding through its peptidyl-prolyl cis-trans isomerase (PPIase) activity. We report that overexpression of wild-type CYPB attenuated aldosterone-induced oxidative stress (evidenced by reduced production of reactive oxygen species and improved mitochondrial dysfunction), ERS (indicated by reduced expression of the ERS markers glucose-regulated protein 78 [GRP78] and C/-EBP homologous protein [CHOP]), and tubular cell apoptosis in comparison with aldosterone-induced human kidney-2 (HK-2) cells. The in vivo study also yielded similar results. Hence, CYPB performs a crucial function in protecting cells against aldosterone-induced oxidative stress, ERS, and tubular cell injury via its PPIase activity. PMID:27732567

  11. Directed evolution and expression tuning of geraniol synthase for efficient geraniol production in Escherichia coli.

    PubMed

    Tashiro, Miki; Fujii, Akira; Kawai-Noma, Shigeko; Saito, Kyoichi; Umeno, Daisuke

    2017-11-17

    To achieve an efficient production of geraniol and its derivatives in Escherichia coli, we aimed to improve the activity of geraniol synthase (GES) through a single round of mutagenesis and screening for higher substrate consumption. We isolated GES variants that outperform their parent in geraniol production. The analysis of GES variants indicated that the expression level of GES was the bottleneck for geraniol synthesis. Over-expression of the mutant GES M53 with a 5'-untranslated sequence designed for high translational efficiency, along with the additional expression of mevalonate pathway enzymes, isopentenyl pyrophosphate isomerase, and geranyl pyrophosphate synthase, yielded 300 mg/L/12 h geraniol and its derivatives (>1000 mg/L/42 h in total) in a shaking flask.

  12. Aldosterone does not alter endothelin B receptor signaling in the inner medullary collecting duct.

    PubMed

    Ramkumar, Nirupama; Stuart, Deborah; Yang, Tianxin; Kohan, Donald E

    2017-03-01

    Recent studies suggest that aldosterone-mediated sulfenic acid modification of the endothelin B receptor (ETB) promotes renal injury in an ischemia/reperfusion model through reduced ETB-stimulated nitric oxide production. Similarly, aldosterone inactivation of ETB signaling promotes pulmonary artery hypertension. Consequently, we asked whether aldosterone inhibits collecting duct ETB signaling; this could promote fluid retention since CD ETB exerts natriuretic and diuretic effects. A mouse inner medullary collecting duct cell line (IMCD3) was treated with aldosterone for 48 h followed by sarafotoxin-6c, an ETB-selective agonist, and extracellular signal-related kinase 1/2 (ERK) phosphorylation assessed. S6c increased the phospho/total-ERK ratio similarly in control and aldosterone-treated cells (aldosterone alone increased phospho/total-ERK). Since cultured IMCD cell lines lack ETB inhibited AVP signaling, the effect of S6c on AVP-stimulated cAMP in acutely isolated IMCD was assessed. Rats (have much higher CD ETB expression than mice) were exposed to 3 days of a normal or low Na + diet, or low Na + diet + desoxycorticosterone acetate. S6c inhibited AVP-stimulated cAMP in rat IMCD by the same degree in the high mineralocorticoid groups compared to controls. Finally, S6c-stimulated cGMP accumulation in cultured IMCD, or S6c-stimulated nitric oxide or cGMP in acutely isolated IMCD, was not affected by prior aldosterone exposure. These findings provide evidence that aldosterone does not modify ETB effects on ERK phosphorylation, AVP-dependent cAMP inhibition, or NO/cGMP accumulation in the IMCD Thus, while aldosterone can inhibit endothelial cell ETB activity to promote hypertension and injury, this response does not appear to occur in the IMCD. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  13. Activation of the Endogenous Renin-Angiotensin-Aldosterone System or Aldosterone Administration Increases Urinary Exosomal Sodium Channel Excretion.

    PubMed

    Qi, Ying; Wang, Xiaojing; Rose, Kristie L; MacDonald, W Hayes; Zhang, Bing; Schey, Kevin L; Luther, James M

    2016-02-01

    Urinary exosomes secreted by multiple cell types in the kidney may participate in intercellular signaling and provide an enriched source of kidney-specific proteins for biomarker discovery. Factors that alter the exosomal protein content remain unknown. To determine whether endogenous and exogenous hormones modify urinary exosomal protein content, we analyzed samples from 14 mildly hypertensive patients in a crossover study during a high-sodium (HS, 160 mmol/d) diet and low-sodium (LS, 20 mmol/d) diet to activate the endogenous renin-angiotensin-aldosterone system. We further analyzed selected exosomal protein content in a separate cohort of healthy persons receiving intravenous aldosterone (0.7 μg/kg per hour for 10 hours) versus vehicle infusion. The LS diet increased plasma renin activity and aldosterone concentration, whereas aldosterone infusion increased only aldosterone concentration. Protein analysis of paired urine exosome samples by liquid chromatography-tandem mass spectrometry-based multidimensional protein identification technology detected 2775 unique proteins, of which 316 exhibited significantly altered abundance during LS diet. Sodium chloride cotransporter (NCC) and α- and γ-epithelial sodium channel (ENaC) subunits from the discovery set were verified using targeted multiple reaction monitoring mass spectrometry quantified with isotope-labeled peptide standards. Dietary sodium restriction or acute aldosterone infusion similarly increased urine exosomal γENaC[112-122] peptide concentrations nearly 20-fold, which correlated with plasma aldosterone concentration and urinary Na/K ratio. Urine exosomal NCC and αENaC concentrations were relatively unchanged during these interventions. We conclude that urinary exosome content is altered by renin-angiotensin-aldosterone system activation. Urinary measurement of exosomal γENaC[112-122] concentration may provide a useful biomarker of ENaC activation in future clinical studies. Copyright © 2016 by

  14. Activation of the Endogenous Renin-Angiotensin-Aldosterone System or Aldosterone Administration Increases Urinary Exosomal Sodium Channel Excretion

    PubMed Central

    Qi, Ying; Wang, Xiaojing; Rose, Kristie L.; MacDonald, W. Hayes; Zhang, Bing; Schey, Kevin L.

    2016-01-01

    Urinary exosomes secreted by multiple cell types in the kidney may participate in intercellular signaling and provide an enriched source of kidney-specific proteins for biomarker discovery. Factors that alter the exosomal protein content remain unknown. To determine whether endogenous and exogenous hormones modify urinary exosomal protein content, we analyzed samples from 14 mildly hypertensive patients in a crossover study during a high-sodium (HS, 160 mmol/d) diet and low-sodium (LS, 20 mmol/d) diet to activate the endogenous renin-angiotensin-aldosterone system. We further analyzed selected exosomal protein content in a separate cohort of healthy persons receiving intravenous aldosterone (0.7 μg/kg per hour for 10 hours) versus vehicle infusion. The LS diet increased plasma renin activity and aldosterone concentration, whereas aldosterone infusion increased only aldosterone concentration. Protein analysis of paired urine exosome samples by liquid chromatography-tandem mass spectrometry–based multidimensional protein identification technology detected 2775 unique proteins, of which 316 exhibited significantly altered abundance during LS diet. Sodium chloride cotransporter (NCC) and α- and γ-epithelial sodium channel (ENaC) subunits from the discovery set were verified using targeted multiple reaction monitoring mass spectrometry quantified with isotope-labeled peptide standards. Dietary sodium restriction or acute aldosterone infusion similarly increased urine exosomal γENaC[112–122] peptide concentrations nearly 20-fold, which correlated with plasma aldosterone concentration and urinary Na/K ratio. Urine exosomal NCC and αENaC concentrations were relatively unchanged during these interventions. We conclude that urinary exosome content is altered by renin-angiotensin-aldosterone system activation. Urinary measurement of exosomal γENaC[112–122] concentration may provide a useful biomarker of ENaC activation in future clinical studies. PMID:26113616

  15. Engineering Isoprene Synthase Expression and Activity in Cyanobacteria.

    PubMed

    Chaves, Julie E; Rueda-Romero, Paloma; Kirst, Henning; Melis, Anastasios

    2017-12-15

    Efforts to heterologously produce quantities of isoprene hydrocarbons (C 5 H 8 ) renewably from CO 2 and H 2 O through the photosynthesis of cyanobacteria face barriers, including low levels of recombinant enzyme accumulation compounded by their slow innate catalytic activity. The present work sought to alleviate the "expression level" barrier upon placing the isoprene synthase (IspS) enzyme in different fusion configurations with the cpcB protein, the highly expressed β-subunit of phycocyanin. Different cpcB*IspS fusion constructs were made, distinguished by the absence or presence of linker amino acids between the two proteins. Composition of linker amino acids was variable with lengths of 7, 10, 16, and 65 amino acids designed to test for optimal activity of the IspS through spatial positioning between the cpcB and IspS. Results showed that fusion constructs with the highly expressed cpcB gene, as the leader sequence, improved transgene expression in the range of 61 to 275-fold over what was measured with the unfused IspS control. However, the specific activity of the IspS enzyme was attenuated in all fusion transformants, possibly because of allosteric effects exerted by the leader cpcB fusion protein. This inhibition varied depending on the nature of the linker amino acids between the cpcB and IspS proteins. In terms of isoprene production, the results further showed a trade-off between specific activity and transgenic enzyme accumulation. For example, the cpcB*L7*IspS strain showed only about 10% the isoprene synthase specific-activity of the unfused cpcB-IspS control, but it accumulated 254-fold more IspS enzyme. The latter more than countered the slower specific activity and made the cpcB*L7*IspS transformant the best isoprene producing strain in this work. Isoprene to biomass yield ratios improved from 0.2 mg g -1 in the unfused cpcB-IspS control to 5.4 mg g -1 in the cpcB*L7*IspS strain, a 27-fold improvement.

  16. The Sucrose Synthase Gene Family in Chinese Pear (Pyrus bretschneideri Rehd.): Structure, Expression, and Evolution.

    PubMed

    Abdullah, Muhammad; Cao, Yungpeng; Cheng, Xi; Meng, Dandan; Chen, Yu; Shakoor, Awais; Gao, Junshan; Cai, Yongping

    2018-05-11

    Sucrose synthase (SS) is a key enzyme involved in sucrose metabolism that is critical in plant growth and development, and particularly quality of the fruit. Sucrose synthase gene families have been identified and characterized in plants various plants such as tobacco, grape, rice, and Arabidopsis . However, there is still lack of detailed information about sucrose synthase gene in pear. In the present study, we performed a systematic analysis of the pear ( Pyrus bretschneideri Rehd.) genome and reported 30 sucrose synthase genes. Subsequently, gene structure, phylogenetic relationship, chromosomal localization, gene duplications, promoter regions, collinearity, RNA-Seq data and qRT-PCR were conducted on these sucrose synthase genes. The transcript analysis revealed that 10 PbSSs genes (30%) were especially expressed in pear fruit development. Additionally, qRT-PCR analysis verified the RNA-seq data and shown that PbSS30 , PbSS24 , and PbSS15 have a potential role in the pear fruit development stages. This study provides important insights into the evolution of sucrose synthase gene family in pear and will provide assistance for further investigation of sucrose synthase genes functions in the process of fruit development, fruit quality and resistance to environmental stresses.

  17. Amplification of mineralocorticoid activity of aldosterone by 18-hydroxy-corticosterone and 18-hydroxy-19-nor-corticosterone in adrenalectomized rats.

    PubMed

    Rosenthal, T; Shani, M; Peleg, E; Harnik, M

    1990-01-01

    A combination of aldosterone (1 micrograms) with either 18-OH-corticosterone (1 micrograms) or 18-OH-19-norcorticosterone (1 micrograms) injected to adrenalectomized rats indicated an amplification of mineralocorticoid activity as expressed by Na/K ratio in urine. Without aldosterone their mineralocorticoid potency was negligible.

  18. Isolation and bacterial expression of a sesquiterpene synthase CDNA clone from peppermint(mentha .chi. piperita, L.) that produces the aphid alarm pheromone (E)-.beta.-farnesene

    DOEpatents

    Croteau, Rodney Bruce; Wildung, Mark Raymond; Crock, John E.

    1999-01-01

    A cDNA encoding (E)-.beta.-farnesene synthase from peppermint (Mentha piperita) has been isolated and sequenced, and the corresponding amino acid sequence has been determined. Accordingly, an isolated DNA sequence (SEQ ID NO:1) is provided which codes for the expression of (E)-.beta.-farnesene synthase (SEQ ID NO:2), from peppermint (Mentha piperita). In other aspects, replicable recombinant cloning vehicles are provided which code for (E)-.beta.-farnesene synthase, or for a base sequence sufficiently complementary to at least a portion of (E)-.beta.-farnesene synthase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding (E)-.beta.-farnesene synthase. Thus, systems and methods are provided for the recombinant expression of the aforementioned recombinant (E)-.beta.-farnesene synthase that may be used to facilitate its production, isolation and purification in significant amounts. Recombinant (E)-.beta.-farnesene synthase may be used to obtain expression or enhanced expression of (E)-.beta.-farnesene synthase in plants in order to enhance the production of (E)-.beta.-farnesene, or may be otherwise employed for the regulation or expression of (E)-.beta.-farnesene synthase, or the production of its product.

  19. New drug therapies interfering with the renin-angiotensin-aldosterone system for resistant hypertension.

    PubMed

    Monge, Matthieu; Lorthioir, Aurélien; Bobrie, Guillaume; Azizi, Michel

    2013-12-01

    There is a persistent need for the development of new antihypertensive drugs, because the control of blood pressure is still not achievable in a significant proportion of hypertensive patients. Since the approval in 2007 of aliskiren, no other new antihypertensive based on new mechanism(s) of action have been approved. In fact, the development of promising novel drugs has been stopped for safety, efficacy or marketing reasons. Despite these difficulties, the pipeline is not dry and different new antihypertensive strategies targeting the renin-angiotensin-aldosterone pathway, are in clinical development stage. The dual angiotensin II receptor-neprilysin inhibitor LCZ696, a single molecule synthetized by cocrystallisation of valsartan and the neprilysin inhibitor prodrug AHU377 is in development for resistant hypertension and for heart failure. Daglutril is a dual neprylisin-endothelin converting enzyme inhibitor which was shown to decrease BP in patients with type 2 diabetic nephropathy. Aldosterone synthase inhibitors and the third and fourth generation non-steroidal dihydropyridine based mineralocorticoid receptors blockers are new ways to target the multiple noxious effects of aldosterone in the kidney, vessels and heart. Centrally acting aminopeptidase A inhibitors block brain angiotensin III formation, one of the main effector peptides of the brain renin angiotensin system. However, a long time will be still necessary to evaluate extensively the efficacy and safety of these new approaches. In the mean time, using appropriate and personalized daily doses of available drugs, decreasing physician inertia, improving treatment adherence, improving access to healthcare and reducing treatment costs remain major objectives to reduce the incidence of resistant hypertension.

  20. Controlling Citrate Synthase Expression by CRISPR/Cas9 Genome Editing for n-Butanol Production in Escherichia coli.

    PubMed

    Heo, Min-Ji; Jung, Hwi-Min; Um, Jaeyong; Lee, Sang-Woo; Oh, Min-Kyu

    2017-02-17

    Genome editing using CRISPR/Cas9 was successfully demonstrated in Esherichia coli to effectively produce n-butanol in a defined medium under microaerobic condition. The butanol synthetic pathway genes including those encoding oxygen-tolerant alcohol dehydrogenase were overexpressed in metabolically engineered E. coli, resulting in 0.82 g/L butanol production. To increase butanol production, carbon flux from acetyl-CoA to citric acid cycle should be redirected to acetoacetyl-CoA. For this purpose, the 5'-untranslated region sequence of gltA encoding citrate synthase was designed using an expression prediction program, UTR designer, and modified using the CRISPR/Cas9 genome editing method to reduce its expression level. E. coli strains with decreased citrate synthase expression produced more butanol and the citrate synthase activity was correlated with butanol production. These results demonstrate that redistributing carbon flux using genome editing is an efficient engineering tool for metabolite overproduction.

  1. Interacting influence of potassium and polychlorinated biphenyl on cortisol and aldosterone biosynthesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Li, L.-A.; Lin, Tsu-Chun Emma

    Giving human adrenocortical H295R cells 14 mM KCl for 24 h significantly induced not only aldosterone biosynthesis but also cortisol biosynthesis. Pre-treating the cells with polychlorinated biphenyl 126 (PCB126) further increased potassium-induced aldosterone and cortisol productions in a dose-dependent manner, but all examined concentrations of PCB126 had little effect on the yields of precursor steroids progesterone and 17-OH-progesterone. Subsequent examinations revealed that CYP11B1 and CYP11B2 genes, responsible for the respective final steps of the cortisol and aldosterone biosynthetic pathways, exhibited increased responsiveness to PCB126 under high potassium. While 10{sup -5} M PCB126 was needed to induce a significant increase inmore » the basal mRNA abundance of either gene, PCB126 could enhance potassium-induced mRNA expression of CYP11B1 at 10{sup -7} M and CYP11B2 at 10{sup -9} M. Actually, potassium and PCB126 synergistically upregulated mRNA expression of both genes. Potassium raised the transcriptional rates of CYP11B1 and CYP11B2 probably through a conserved Ad5 cis-element, whereas PCB126 appeared to regulate these two genes at the post-transcriptional level. Positive potassium-PCB126 synergism was also detected in CYP11B2 enzyme activity estimated by aldosterone/progesterone ratio. In contrast, potassium and PCB126 increased CYP11B1 enzyme activity or cortisol/17-OH-progesterone ratio additively. Moreover, potassium improved the time effect of PCB126 on gene expression and enzyme activity of CYP11B2, but not the PCB126 time response of CYP11B1. These data demonstrated that potassium differentially enhanced the potency of PCB126 to induce CYP11B1- and CYP11B2-mediated steroidogenesis.« less

  2. Co-expression of peppermint geranyl diphosphate synthase small subunit enhances monoterpene production in transgenic tobacco plants.

    PubMed

    Yin, Jun-Lin; Wong, Woon-Seng; Jang, In-Cheol; Chua, Nam-Hai

    2017-02-01

    Monoterpenes are important for plant survival and useful to humans. In addition to their function in plant defense, monoterpenes are also used as flavors, fragrances and medicines. Several metabolic engineering strategies have been explored to produce monoterpene in tobacco but only trace amounts of monoterpenes have been detected. We investigated the effects of Solanum lycopersicum 1-deoxy-d-xylulose-5-phosphate synthase (SlDXS), Arabidopsis thaliana geranyl diphosphate synthase 1 (AtGPS) and Mentha × piperita geranyl diphosphate synthase small subunit (MpGPS.SSU) on production of monoterpene and geranylgeranyl diphosphate (GGPP) diversities, and plant morphology by transient expression in Nicotiana benthamiana and overexpression in transgenic Nicotiana tabacum. We showed that MpGPS.SSU could enhance the production of various monoterpenes such as (-)-limonene, (-)-linalool, (-)-α-pinene/β-pinene or myrcene, in transgenic tobacco by elevating geranyl diphosphate synthase (GPS) activity. In addition, overexpression of MpGPS.SSU in tobacco caused early flowering phenotype and increased shoot branching by elevating contents of GA 3 and cytokinins due to upregulated transcript levels of several plastidic 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway genes, geranylgeranyl diphosphate synthases 3 (GGPPS3) and GGPPS4. Our method would allow the identification of new monoterpene synthase genes using transient expression in N. benthamiana and the improvement of monoterpene production in transgenic tobacco plants. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  3. Aldosterone, Parathyroid Hormone, and the Use of Renin-Angiotensin-Aldosterone System Inhibitors: The Multi-Ethnic Study of Atherosclerosis

    PubMed Central

    Brown, Jenifer; de Boer, Ian H.; Robinson-Cohen, Cassianne; Siscovick, David S.; Kestenbaum, Bryan; Allison, Matthew

    2015-01-01

    Context: Aldosterone and PTH are implicated in the pathogenesis of cardiovascular and skeletal diseases. An expanding body of evidence supports a bidirectional and positive physiologic relationship between aldosterone and PTH. Large population-based studies confirming this relationship, and whether it may be targeted as a potential method to mitigate the clinical consequences associated with excess aldosterone and PTH, are needed. Objective: We hypothesized that higher aldosterone levels would associate with higher PTH, and that the use of renin-angiotensin-aldosterone system (RAAS) inhibitors would predict lower PTH in a large, multi-ethnic, community-based cohort. Design, Setting, Participants: We conducted cross-sectional analyses of participants in the Multi-Ethnic Study of Atherosclerosis without apparent primary hyperparathyroidism or chronic kidney disease (n = 5668). We evaluated associations of RAAS inhibitor use with PTH concentration among 1888 treated hypertensive participants. We also tested associations of serum aldosterone concentration with PTH concentration among 1547 participants with these measurements. Outcome: Serum PTH concentration. Results: Higher aldosterone associated with higher PTH (β = 0.19 pg/ml per 1 ng/dl of aldosterone, P < .0001), and this finding was most pronounced among those with a primary hyperaldosteronism-like phenotype. There was a stepwise increment in PTH when comparing untreated normotensives, hypertensives using RAAS inhibitors, untreated hypertensives, and treated hypertensives using non-RAAS inhibitors (40.8, 45.0, 46.2, 47.1 pg/ml, respectively). The use of any RAAS inhibitor independently associated with lower PTH (β = −2.327 pg/ml per use of RAAS inhibitor, P = .006), when compared with the use of any non-RAAS inhibitor medication. Conclusions: Higher serum aldosterone concentration is associated with higher serum PTH concentration, and the use of RAAS inhibitors is associated with lower PTH concentration

  4. Overview of aldosterone-related genetic syndromes and recent advances.

    PubMed

    Zennaro, Maria-Christina; Fernandes-Rosa, Fabio L; Boulkroun, Sheerazed

    2018-06-01

    Primary aldosteronism is the most common form of secondary hypertension. Early diagnosis and treatment are key to cure of hypertension and prevention of cardiovascular complications. Recent genetic discoveries have improved our understanding on the pathophysiology of aldosterone production and triggered the development of new diagnostic procedures and targeted treatments for primary aldosteronism. Different inherited genetic abnormalities distinguish specific forms of familial hyperaldosteronism. Somatic mutations are found not only in aldosterone-producing adenoma (APA), leading to primary aldosteronism, but also in aldosterone producing cell clusters of normal and micronodules from image-negative adrenal glands. Genetic knowledge has allowed the discovery of surrogate biomarkers and specific pharmacological inhibitors. Ageing appears to be associated with dysregulated and relatively autonomous aldosterone production. New biochemical markers and pharmacological approaches may allow preoperative identification of somatic mutation carriers and use of targeted treatments.

  5. Aldosterone Activates Transcription Factor Nrf2 in Kidney Cells Both In Vitro and In Vivo

    PubMed Central

    Oteiza, Patricia I.; Link, Samuel; Hey, Valentin; Stopper, Helga; Schupp, Nicole

    2014-01-01

    Abstract Aims: An increased kidney cancer risk was found in hypertensive patients, who frequently exhibit hyperaldosteronism, known to contribute to kidney injury, with oxidative stress playing an important role. The capacity of kidney cells to up-regulate transcription factor nuclear factor-erythroid-2-related factor 2 (Nrf2), a key regulator of the cellular antioxidative defense, as a prevention of aldosterone-induced oxidative damage was investigated both in vitro and in vivo. Results: Aldosterone activated Nrf2 and increased the expression of enzymes involved in glutathione (GSH) synthesis and detoxification. This activation depended on the mineralocorticoid receptor (MR) and oxidative stress. In vitro, Nrf2 activation, GSH amounts, and target gene levels decreased after 24 h, while oxidant levels remained high. Nrf2 activation could not protect cells against oxidative DNA damage, as aldosterone-induced double-strand breaks and 7,8-dihydro-8-oxo-guanine (8-oxodG) lesions steadily rose. The Nrf2 activator sulforaphane enhanced the Nrf2 response both in vitro and in vivo, thereby preventing aldosterone-induced DNA damage. In vivo, Nrf2 activation further had beneficial effects on the aldosterone-caused blood pressure increase and loss of kidney function. Innovation: This is the first study showing the activation of Nrf2 by aldosterone. Moreover, the results identify sulforaphane as a substance that is capable of preventing aldosterone-induced damage both in vivo and in vitro. Conclusion: Aldosterone-induced Nrf2 adaptive response cannot neutralize oxidative actions of chronically increased aldosterone, which, therefore could be causally involved in the increased cancer incidence of hypertensive individuals. Enhancing the cellular antioxidative defense with sulforaphane might exhibit beneficial effects. Antioxid. Redox Signal. 21, 2126–2142. PMID:24512358

  6. Human interventions to characterize novel relationships between the renin-angiotensin-aldosterone system and parathyroid hormone.

    PubMed

    Brown, Jenifer M; Williams, Jonathan S; Luther, James M; Garg, Rajesh; Garza, Amanda E; Pojoga, Luminita H; Ruan, Daniel T; Williams, Gordon H; Adler, Gail K; Vaidya, Anand

    2014-02-01

    Observational studies in primary hyperaldosteronism suggest a positive relationship between aldosterone and parathyroid hormone (PTH); however, interventions to better characterize the physiological relationship between the renin-angiotensin-aldosterone system (RAAS) and PTH are needed. We evaluated the effect of individual RAAS components on PTH using 4 interventions in humans without primary hyperaldosteronism. PTH was measured before and after study (1) low-dose angiotensin II (Ang II) infusion (1 ng/kg per minute) and captopril administration (25 mg×1); study (2) high-dose Ang II infusion (3 ng/kg per minute); study (3) blinded crossover randomization to aldosterone infusion (0.7 µg/kg per hour) and vehicle; and study (4) blinded randomization to spironolactone (50 mg/daily) or placebo for 6 weeks. Infusion of Ang II at 1 ng/kg per minute acutely increased aldosterone (+148%) and PTH (+10.3%), whereas Ang II at 3 ng/kg per minute induced larger incremental changes in aldosterone (+241%) and PTH (+36%; P<0.01). Captopril acutely decreased aldosterone (-12%) and PTH (-9.7%; P<0.01). In contrast, aldosterone infusion robustly raised serum aldosterone (+892%) without modifying PTH. However, spironolactone therapy during 6 weeks modestly lowered PTH when compared with placebo (P<0.05). In vitro studies revealed the presence of Ang II type I and mineralocorticoid receptor mRNA and protein expression in normal and adenomatous human parathyroid tissues. We observed novel pleiotropic relationships between RAAS components and the regulation of PTH in individuals without primary hyperaldosteronism: the acute modulation of PTH by the RAAS seems to be mediated by Ang II, whereas the long-term influence of the RAAS on PTH may involve aldosterone. Future studies to evaluate the impact of RAAS inhibitors in treating PTH-mediated disorders are warranted.

  7. Obesity, hypertension and aldosterone: is leptin the link?

    PubMed

    Xie, Ding; Bollag, Wendy B

    2016-07-01

    Obesity is a serious health hazard with rapidly increasing prevalence in the United States. In 2014, the World Health Organization estimated that nearly 2 billion people worldwide were overweight with an estimated 600 million of these obese. Obesity is associated with many chronic diseases, including cardiovascular disease and hypertension. Data from the Framingham Heart study suggest that approximately 78% of the risk for hypertension in men and 65% in women is related to excess body weight, a relationship that is further supported by studies showing increases in blood pressure with weight gain and decreases with weight loss. However, the exact mechanism by which excess body fat induces hypertension remains poorly understood. Several clinical studies have demonstrated elevated plasma aldosterone levels in obese individuals, especially those with visceral adiposity, with decreased aldosterone levels measured in concert with reduced blood pressure following weight loss. Since aldosterone is a mineralocorticoid hormone that regulates blood volume and pressure, serum aldosterone levels may link obesity and hypertension. Nevertheless, the mechanism by which obesity induces aldosterone production is unclear. A recent study by Belin de Chantemele and coworkers suggests that one adipose-released factor, leptin, is a direct agonist for aldosterone secretion; other adipose-related factors may also contribute to elevated aldosterone levels in obesity, such as very low-density lipoprotein (VLDL), the levels of which are elevated in obesity and which also directly stimulates aldosterone biosynthesis. This focused review explores the possible roles of leptin and VLDL in modulating aldosterone secretion to underlie obesity-associated hypertension. © 2016 Society for Endocrinology.

  8. A Novel Phenotype of Familial Hyperaldosteronism Type III: Concurrence of Aldosteronism and Cushing's Syndrome

    PubMed Central

    Liu, Guanghua; Wang, Fen; Jiang, Jun; Yan, Zhaoli; Zhang, Dianxi; Zhang, Yinsheng

    2016-01-01

    Context: To date, all the familial hyperaldosteronism type III (FH-III) patients reported presenting with typical primary aldosteronism (PA), without showing other adrenal hormone abnormalities. Objective: This study characterized a novel phenotype of FH-III and explored the possible pathogenesis. Patients and Methods: A male patient presented with severe hypertension and hypokalemia at the age of 2 years and developed Cushing's syndrome at 20 years. He was diagnosed with PA and Cushing's syndrome on the basis of typical biochemical findings. He had massive bilateral adrenal hyperplasia and underwent left adrenalectomy. KCNJ5 was sequenced, and secretion of aldosterone and cortisol were observed both in vivo and in vitro. Results: A heterozygous germline p.Glu145Gln mutation of KCNJ5 was identified. ARMC5, PRKAR1A, PDE8B, PDE11A, and PRKACA genes and β-catenin, P53 immunoactivity were normal in the adrenal. CYP11B2 was highly expressed, whereas mRNA expression of CYP11B1, CYP17A1, and STAR was relatively low in the hyperplastic adrenal, compared with normal adrenal cortex and other adrenal diseases. In the primary cell culture of the resected hyperplastic adrenal, verapamil and nifedipine, two calcium channel blockers, markedly inhibited the secretion of both aldosterone and cortisol and the mRNA expression of CYP11B1, CYP11B2, CYP17A1, and STAR. Conclusions: We presented the first FH-III patient who had both severe PA and Cushing's syndrome. Hypersecretion of cortisol might be ascribed to overly large size of the hyperplastic adrenal because CYP11B1 expression was relatively low in his adrenal. Like aldosterone, synthesis and secretion of cortisol in the mutant adrenal may be mediated by voltage-gated Ca2+ channels. PMID:27403928

  9. LGR5 Activates Noncanonical Wnt Signaling and Inhibits Aldosterone Production in the Human Adrenal.

    PubMed

    Shaikh, Lalarukh Haris; Zhou, Junhua; Teo, Ada E D; Garg, Sumedha; Neogi, Sudeshna Guha; Figg, Nichola; Yeo, Giles S; Yu, Haixiang; Maguire, Janet J; Zhao, Wanfeng; Bennett, Martin R; Azizan, Elena A B; Davenport, Anthony P; McKenzie, Grahame; Brown, Morris J

    2015-06-01

    Aldosterone synthesis and cellularity in the human adrenal zona glomerulosa (ZG) is sparse and patchy, presumably due to salt excess. The frequency of somatic mutations causing aldosterone-producing adenomas (APAs) may be a consequence of protection from cell loss by constitutive aldosterone production. The objective of the study was to delineate a process in human ZG, which may regulate both aldosterone production and cell turnover. This study included a comparison of 20 pairs of ZG and zona fasciculata transcriptomes from adrenals adjacent to an APA (n = 13) or a pheochromocytoma (n = 7). Interventions included an overexpression of the top ZG gene (LGR5) or stimulation by its ligand (R-spondin-3). A transcriptome profile of ZG and zona fasciculata and aldosterone production, cell kinetic measurements, and Wnt signaling activity of LGR5 transfected or R-spondin-3-stimulated cells were measured. LGR5 was the top gene up-regulated in ZG (25-fold). The gene for its cognate ligand R-spondin-3, RSPO3, was 5-fold up-regulated. In total, 18 genes associated with the Wnt pathway were greater than 2-fold up-regulated. ZG selectivity of LGR5, and its absence in most APAs, were confirmed by quantitative PCR and immunohistochemistry. Both R-spondin-3 stimulation and LGR5 transfection of human adrenal cells suppressed aldosterone production. There was reduced proliferation and increased apoptosis of transfected cells, and the noncanonical activator protein-1/Jun pathway was stimulated more than the canonical Wnt pathway (3-fold vs 1.3-fold). ZG of adrenal sections stained positive for apoptosis markers. LGR5 is the most selectively expressed gene in human ZG and reduces aldosterone production and cell number. Such conditions may favor cells whose somatic mutation reverses aldosterone inhibition and cell loss.

  10. Isolation and bacterial expression of a sesquiterpene synthase cDNA clone from peppermint (Mentha x piperita, L.) that produces the aphid alarm pheromone (E)-.beta.-farnesene

    DOEpatents

    Croteau, Rodney Bruce; Crock, John E.

    2005-01-25

    A cDNA encoding (E)-.beta.-farnesene synthase from peppermint (Mentha piperita) has been isolated and sequenced, and the corresponding amino acid sequence has been determined. Accordingly, an isolated DNA sequence (SEQ ID NO:1) is provided which codes for the expression of (E)-.beta.-farnesene synthase (SEQ ID NO:2), from peppermint (Mentha piperita). In other aspects, replicable recombinant cloning vehicles are provided which code for (E)-.beta.-farnesene synthase, or for a base sequence sufficiently complementary to at least a portion of (E)-.beta.-farnesene synthase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding (E)-.beta.-farnesene synthase. Thus, systems and methods are provided for the recombinant expression of the aforementioned recombinant (E)-.beta.-famesene synthase that may be used to facilitate its production, isolation and purification in significant amounts. Recombinant (E)-.beta.-farnesene synthase may be used to obtain expression or enhanced expression of (E)-.beta.-famesene synthase in plants in order to enhance the production of (E)-.beta.-farnesene, or may be otherwise employed for the regulation or expression of (E)-.beta.-farnesene synthase, or the production of its product.

  11. Mineralocorticoid receptor antagonism protects the aorta from vascular smooth muscle cell proliferation and collagen deposition in a rat model of adrenal aldosterone-producing adenoma.

    PubMed

    Yan, Yongji; Wang, Chao; Lu, Yiqin; Gong, Huijie; Wu, Zhun; Ma, Xin; Li, Hongzhao; Wang, Baojun; Zhang, Xu

    2018-02-01

    The number of patients with adrenal aldosterone-producing adenomas (APAs) has gradually increased. However, even after adenoma resection, some patients still suffer from high systolic blood pressure (SBP), which is possibly due to great arterial remodeling. Moreover, mineralocorticoid receptors (MRs) were found to be expressed in vascular smooth muscle cells (VSMCs). This study aims to determine whether MR antagonism protects the aorta from aldosterone-induced aortic remolding. Male rats were subcutaneously implanted with an osmotic minipumps and randomly divided into four groups: control; aldosterone (1 μg/h); aldosterone plus a specific MR antagonist, eplerenone (100 mg/kg/day); and aldosterone plus a vasodilator, hydralazine (25 mg/kg/day). After 8 weeks of infusion, aortic smooth muscle cell proliferation and collagen deposition, as well as the MDM2 and TGF-β1 expression levels in the aorta, were examined. Model rats with APAs were successfully constructed. Compared with the control rats, the model rats exhibited (1) marked SBP elevation, (2) no significant alteration in aortic morphology, (3) increased VSMC proliferation and MDM2 expression in the aorta, and (4) enhanced total collagen and collagen III depositions in the aorta, accompanied with up-regulated expression of TGF-β1. These effects were significantly inhibited by co-administration with eplerenone but not with hydralazine. These findings suggested that specific MR antagonism protects the aorta from aldosterone-induced VSMC proliferation and collagen deposition.

  12. Contralateral suppression of aldosterone at adrenal venous sampling predicts hyperkalemia following adrenalectomy for primary aldosteronism.

    PubMed

    Shariq, Omair A; Bancos, Irina; Cronin, Patricia A; Farley, David R; Richards, Melanie L; Thompson, Geoffrey B; Young, William F; McKenzie, Travis J

    2018-01-01

    We aimed to determine whether a greater degree of contralateral suppression of aldosterone secretion at adrenal venous sampling predicted the development of postoperative hyperkalemia after unilateral adrenalectomy for primary aldosteronism. A retrospective analysis of patients undergoing unilateral adrenalectomy for primary aldosteronism between 2004-2015 was performed. Clinical and biochemical parameters of patients who developed hyperkalemia (≥5.2 mmol/L) after unilateral adreanlectomy were compared with those who remained normokalemic. The contralateral suppression index was defined as the aldosterone-to-cortisol ratio from the nondominant adrenal vein divided by the aldosterone-to-cortisol ratio from the external iliac vein. Of 192 patients who met criteria for inclusion, 12 (6.3%) developed hyperkalemia (median serum potassium 5.5 mmol/L, range 5.2-6.2 mmol/L), with a median time to onset of 13.5 days (range 7-55 days). Five patients had transiently increased serum potassium concentrations that normalized spontaneously. Four patients received mineralocorticoid replacement therapy with fludrocortisone. On univariate analysis, hyperkalemic patients had slightly greater preoperative serum creatinine levels (1.2 vs 1.0 mg/dL, P = .01), higher postoperative creatinine (1.3 vs 1.0 mg/dL, P = .02), lesser median contralateral suppression index (0.14 vs 0.27, P = .03), and larger adenomas (1.9 vs 1.4 cm, P = .02). On multivariable logistic regression, the contralateral suppression index remained the only significant predictor of postoperative hyperkalemia (P = .04) with an optimal cut-off of <0.47. Hyperkalemia after unilateral adrenalectomy for primary aldosteronism is uncommon and usually transient, but may require mineralocorticoid supplementation. Patients with a contralateral suppression index of <0.47 require meticulous follow-up and monitoring of serum potassium concentrations after unilateral adrenalectomy. Copyright © 2017

  13. The Occurrence of Apparent Bilateral Aldosterone Suppression in Adrenal Vein Sampling for Primary Aldosteronism

    PubMed Central

    Shibayama, Yui; Wada, Norio; Naruse, Mitsuhide; Kurihara, Isao; Ito, Hiroshi; Yoneda, Takashi; Takeda, Yoshiyu; Umakoshi, Hironobu; Tsuiki, Mika; Ichijo, Takamasa; Fukuda, Hisashi; Katabami, Takuyuki; Yoshimoto, Takanobu; Ogawa, Yoshihiro; Kawashima, Junji; Ohno, Yuichi; Sone, Masakatsu; Fujita, Megumi; Takahashi, Katsutoshi; Shibata, Hirotaka; Kamemura, Kohei; Fujii, Yuichi; Yamamoto, Koichi; Suzuki, Tomoko

    2018-01-01

    Abstract Context In adrenal venous sampling (AVS) for patients with primary aldosteronism (PA), apparent bilateral aldosterone suppression (ABAS), defined as lower aldosterone/cortisol ratios in the bilateral adrenal veins than that in the inferior vena cava, is occasionally experienced. ABAS is uninterpretable with respect to lateralization of excess aldosterone production. We previously reported that ABAS was not a rare phenomenon and was significantly reduced after adrenocorticotropic hormone (ACTH) administration. Objective To validate the effects of ACTH administration and adding sampling positions in the left adrenal vein on the prevalence of ABAS in the larger Japan Primary Aldosteronism Study. Patients The data from 1689 patients with PA who underwent AVS between January 2006 and October 2016 were studied. All patients in the previous study, the West Japan Adrenal Vein Sampling study, were excluded. Outcome Measurements The prevalence of ABAS was investigated at two sampling positions in the left adrenal vein, the central vein and the common trunk, without and with ACTH administration. Results The prevalence of ABAS with ACTH administration was significantly lower than that without ACTH administration [without ACTH vs with ACTH: 79/440 (18.0%) vs 45/591 (7.6%); P < 0.001]. With ACTH administration, the prevalence of ABAS was not different between the sampling position, at the central vein and at the common trunk [33/591 (5.6%) vs 32/591 (5.4%); P = 1.00]. Conclusions The effectiveness of ACTH administration for the reduction of ABAS in AVS regardless of the sampling position in the left adrenal vein was confirmed in the larger cohort. PMID:29687091

  14. Regulation of galactan synthase expression to modify galactan content in plants

    DOEpatents

    None

    2017-08-22

    The disclosure provides methods of engineering plants to modulate galactan content. Specifically, the disclosure provides methods for engineering a plant to increase the galactan content in a plant tissue by inducing expression of beta-1,4-galactan synthase (GALS), modulated by a heterologous promoter. Further disclosed are the methods of modulating expression level of GALS under the regulation of a transcription factor, as well as overexpression of UDP-galactose epimerse in the same plant tissue. Tissue specific promoters and transcription factors can be used in the methods are also provided.

  15. Association of Circulating Renin and Aldosterone With Osteocalcin and Bone Mineral Density in African Ancestry Families.

    PubMed

    Kuipers, Allison L; Kammerer, Candace M; Pratt, J Howard; Bunker, Clareann H; Wheeler, Victor W; Patrick, Alan L; Zmuda, Joseph M

    2016-05-01

    Hypertension is associated with accelerated bone loss, and the renin-angiotensin-aldosterone system is a key regulator of blood pressure. Although components of this system are expressed in human bone cells, studies in humans are sparse. Thus, we studied the association of circulating renin and aldosterone with osteocalcin and bone mineral density. We recruited 373 African ancestry family members without regard to health status from 6 probands (mean family size: 62 and relative pairs: 1687). Participants underwent a clinical examination, dual-energy x-ray absorptiometry, and quantitative computed tomographic scans. Renin activity, aldosterone concentration, and osteocalcin were measured in fasting blood samples. Aldosterone/renin ratio was calculated as aldosterone concentration/renin activity. All models were analyzed using pedigree-based variance components methods. Full models included adjustment for age, sex, body composition, comorbidities, lifestyle factors, blood pressure, and antihypertensive medication. Higher renin activity was significantly associated with lower total osteocalcin and with higher trabecular bone mineral density (both P<0.01). There were also significant genetic correlations between renin activity and whole-body bone mineral density. There were no associations with aldosterone concentration in any model and results for aldosterone/renin ratio were similar to those for renin activity. This is the first study to report a significant association between renin activity and a marker of bone turnover and bone mineral density in generally healthy individuals. Also, there is evidence for significant genetic pleiotropy and, thus, there may be a shared biological mechanism underlying both the renin-angiotensin-aldosterone system and bone metabolism that is independent of hypertension. © 2016 American Heart Association, Inc.

  16. ASSOCIATION OF CIRCULATING RENIN AND ALDOSTERONE WITH OSTEOCALCIN AND BONE MINERAL DENSITY IN AFRICAN ANCESTRY FAMILIES

    PubMed Central

    Kuipers, Allison L; Kammerer, Candace M; Howard Pratt, J; Bunker, Clareann H; Wheeler, Victor W; Patrick, Alan L; Zmuda, Joseph M

    2016-01-01

    Hypertension is associated with accelerated bone loss and the renin-angiotensin-aldosterone system is a key regulator of blood pressure. Although components of this system are expressed in human bone cells, studies in humans are sparse. Thus, we studied the association of circulating renin and aldosterone with osteocalcin and bone mineral density. We recruited 373 African ancestry family members without regard to health status from 6 probands (mean family size: 62; relative pairs: 1687). Participants underwent a clinical exam, dual energy x-ray absorptiometry, and quantitative computed tomography scans. Renin activity, aldosterone concentration, and osteocalcin were measured in fasting blood samples. Aldosterone to renin ratio was calculated as aldosterone concentration/renin activity. All models were analyzed using pedigree-based variance components methods. Full models included adjustment for age, sex, body composition, co-morbidities, lifestyle factors, blood pressure, and antihypertensive medication. Higher renin activity was significantly associated with lower total osteocalcin and with higher trabecular bone mineral density (both p<0.01). There were also significant genetic correlations between renin activity and whole body bone mineral density. There were no associations with aldosterone concentration in any model and results for aldosterone to renin ratio were similar to those for renin activity. This is the first study to report a significant association between renin activity and a marker of bone turnover and bone mineral density in generally healthy individuals. Also, there is evidence for significant genetic pleiotropy and, thus, there may be a shared biologic mechanism underlying both the renin-angiotensin-aldosterone system and bone metabolism that is independent of hypertension. PMID:26975710

  17. Aldosterone downregulates delayed rectifier potassium currents through an angiotensin type 1 receptor-dependent mechanism.

    PubMed

    Lv, Yankun; Wang, Yanjun; Zhu, Xiaoran; Zhang, Hua

    2018-01-01

    We have previously shown that aldosterone downregulates delayed rectifier potassium currents (I Ks ) via activation of the mineralocorticoid receptor (MR) in adult guinea pig cardiomyocytes. Here, we investigate whether angiotensin II/angiotensin type 1 receptor (AngII/AT1R) and intracellular calcium also play a role in these effects. Ventricular cardiomyocytes were isolated from adult guinea pigs and incubated with aldosterone (1 μmol·L -1 ) either alone or in combination with enalapril (1 μmol·L -1 ), losartan (1 μmol·L -1 ), nimodipine (1 μmol·L -1 ), or BAPTA-AM (2.5 μmol·L -1 ) for 24 h. We used the conventional whole cell patch-clamp technique to record the I Ks component. In addition, we evaluated expression of the I Ks subunits KCNQ1 and KCNE1 using Western blotting. Our results showed that both enalapril and losartan, but not nimodipine or BAPTA-AM, completely reversed the aldosterone-induced inhibition of I Ks and its effects on KCNQ1/KCNE1 protein levels. Furthermore, we found that AngII/AT1R mediates the inhibitory effects of aldosterone on I Ks . Finally, the downregulation of I Ks induced by aldosterone did not occur secondarily to a change in intracellular calcium concentrations. Taken together, our findings demonstrate that crosstalk between MR and AT1R underlies the effects of aldosterone, and provide new insights into the mechanism underlying potassium channels.

  18. Stachyose synthesis in seeds of adzuki bean (Vigna angularis): molecular cloning and functional expression of stachyose synthase.

    PubMed

    Peterbauer, T; Mucha, J; Mayer, U; Popp, M; Glössl, J; Richter, A

    1999-12-01

    Stachyose is the major soluble carbohydrate in seeds of a number of important crop species. It is synthesized from raffinose and galactinol by the action of stachyose synthase (EC 2.4.1.67). We report here on the identification of a cDNA encoding stachyose synthase from seeds of adzuki bean (Vigna angularis Ohwi et Ohashi). Based on internal amino acid sequences of the enzyme purified from adzuki bean, oligonucleotides were designed and used to amplify corresponding sequences from adzuki bean cDNA by RT-PCR, followed by rapid amplification of cDNA ends (RACE-PCR). The complete cDNA sequence comprised 3046 nucleotides and included an open reading frame which encoded a polypeptide of 857 amino acid residues. The entire coding region was amplified by PCR, engineered into the baculovirus expression vector pVL1393 and introduced into Spodoptera frugiperda (Sf21) insect cells for heterologous expression. The recombinant protein was immunologically reactive with polyclonal antibodies raised against stachyose synthase purified from adzuki bean and was shown to be a functional stachyose synthase with the same catalytic properties as its native counterpart. High levels of stachyose synthase mRNA were transiently accumulated midway through seed development, and the enzyme was also present in mature seeds and during germination.

  19. A serine protease inhibitor attenuates aldosterone-induced kidney injuries via the suppression of plasmin activity.

    PubMed

    Kakizoe, Yutaka; Miyasato, Yoshikazu; Onoue, Tomoaki; Nakagawa, Terumasa; Hayata, Manabu; Uchimura, Kohei; Morinaga, Jun; Mizumoto, Teruhiko; Adachi, Masataka; Miyoshi, Taku; Sakai, Yoshiki; Tomita, Kimio; Mukoyama, Masashi; Kitamura, Kenichiro

    2016-10-01

    Emerging evidence has suggested that aldosterone has direct deleterious effects on the kidney independently of its hemodynamic effects. However, the detailed mechanisms of these direct effects remain to be elucidated. We have previously reported that camostat mesilate (CM), a synthetic serine protease inhibitor, attenuated kidney injuries in Dahl salt-sensitive rats, remnant kidney rats, and unilateral ureteral obstruction rats, suggesting that some serine proteases would be involved in the pathogenesis of kidney injuries. The current study was conducted to investigate the roles of serine proteases and the beneficial effects of CM in aldosterone-related kidney injuries. We observed a serine protease that was activated by aldosterone/salt in rat kidney lysate, and identified it as plasmin with liquid chromatography-tandem mass spectrometry. Plasmin increased pro-fibrotic and inflammatory gene expressions in rat renal fibroblast cells. CM inhibited the protease activity of plasmin and suppressed cell injury markers induced by plasmin in the fibroblast cells. Furthermore, CM ameliorated glomerulosclerosis and interstitial fibrosis in the kidney of aldosterone/salt-treated rats. Our findings indicate that plasmin has important roles in kidney injuries that are induced by aldosterone/salt, and that serine protease inhibitor could provide a new strategy for the treatment of aldosterone-associated kidney diseases in humans. Copyright © 2016 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  20. Enhanced Toxic Metal Accumulation in Engineered Bacterial Cells Expressing Arabidopsis thaliana Phytochelatin Synthase

    PubMed Central

    Sauge-Merle, Sandrine; Cuiné, Stéphan; Carrier, Patrick; Lecomte-Pradines, Catherine; Luu, Doan-Trung; Peltier, Gilles

    2003-01-01

    Phytochelatins (PCs) are metal-binding cysteine-rich peptides, enzymatically synthesized in plants and yeasts from glutathione in response to heavy metal stress by PC synthase (EC 2.3.2.15). In an attempt to increase the ability of bacterial cells to accumulate heavy metals, the Arabidopsis thaliana gene encoding PC synthase (AtPCS) was expressed in Escherichia coli. A marked accumulation of PCs was observed in vivo together with a decrease in the glutathione cellular content. When bacterial cells expressing AtPCS were placed in the presence of heavy metals such as cadmium or the metalloid arsenic, cellular metal contents were increased 20- and 50-fold, respectively. We discuss the possibility of using genes of the PC biosynthetic pathway to design bacterial strains or higher plants with increased abilities to accumulate toxic metals, and also arsenic, for use in bioremediation and/or phytoremediation processes. PMID:12514032

  1. The Expression of Type-1 and Type-2 Nitric Oxide Synthase in Selected Tissues of the Gastrointestinal Tract during Mixed Mycotoxicosis

    PubMed Central

    Gajęcka, Magdalena; Stopa, Ewa; Tarasiuk, Michał; Zielonka, Łukasz; Gajęcki, Maciej

    2013-01-01

    The aim of the study was to verify the hypothesis that intoxication with low doses of mycotoxins leads to changes in the mRNA expression levels of nitric oxide synthase-1 and nitric oxide synthase-2 genes in tissues of the gastrointestinal tract and the liver. The experiment involved four groups of immature gilts (with body weight of up to 25 kg) which were orally administered zearalenone in a daily dose of 40 μg/kg BW (group Z, n = 18), deoxynivalenol at 12 μg/kg BW (group D, n = 18), zearalenone and deoxynivalenol (group M, n = 18) or placebo (group C, n = 21) over a period of 42 days. The lowest mRNA expression levels of nitric oxide synthase-1 and nitric oxide synthase-2 genes were noted in the sixth week of the study, in particular in group M. Our results suggest that the presence of low mycotoxin doses in feed slows down the mRNA expression of both nitric oxide synthase isomers, which probably lowers the concentrations of nitric oxide, a common precursor of inflammation. PMID:24284830

  2. Aldosterone and parathyroid hormone: a precarious couple for cardiovascular disease.

    PubMed

    Tomaschitz, Andreas; Ritz, Eberhard; Pieske, Burkert; Fahrleitner-Pammer, Astrid; Kienreich, Katharina; Horina, Jörg H; Drechsler, Christiane; März, Winfried; Ofner, Michael; Pieber, Thomas R; Pilz, Stefan

    2012-04-01

    Animal and human studies support a clinically relevant interaction between aldosterone and parathyroid hormone (PTH) levels and suggest an impact of the interaction on cardiovascular (CV) health. This review focuses on mechanisms behind the bidirectional interactions between aldosterone and PTH and their potential impact on the CV system. There is evidence that PTH increases the secretion of aldosterone from the adrenals directly as well as indirectly by activating the renin-angiotensin system. Upregulation of aldosterone synthesis might contribute to the higher risk of arterial hypertension and of CV damage in patients with primary hyperparathyroidism. Furthermore, parathyroidectomy is followed by decreased blood pressure levels and reduced CV morbidity as well as lower renin and aldosterone levels. In chronic heart failure, the aldosterone activity is inappropriately elevated, causing salt retention; it has been argued that the resulting calcium wasting causes secondary hyperparathyroidism. The ensuing intracellular calcium overload and oxidative stress, caused by PTH and amplified by the relative aldosterone excess, may increase the risk of CV events. In the setting of primary aldosteronism, renal and faecal calcium loss triggers increased PTH secretion which in turn aggravates aldosterone secretion and CV damage. This sequence explains why adrenalectomy and blockade of the mineralocorticoid receptor tend to decrease PTH levels in patients with primary aldosteronism. In view of the reciprocal interaction between aldosterone and PTH and the potentially ensuing CV damage, studies are urgently needed to evaluate diagnostic and therapeutic strategies addressing the interaction between the two hormones.

  3. Parathyroid Gland Function in Primary Aldosteronism.

    PubMed

    Asbach, E; Bekeran, M; Reincke, M

    2015-12-01

    Primary aldosteronism (PA) is the most frequent cause of secondary arterial hypertension. Beyond its effects on intravascular volume and blood pressure, PA causes metabolic alterations and a higher cardiovascular morbidity, which is reduced by PA-directed therapy. Experimental studies demonstrated that mineralocorticoid excess may also influence mineral homeostasis. A role in cardiovascular disease has also been attributed to parathyroid hormone (PTH). Increasing evidence supports a bidirectional interaction between aldosterone and PTH.Primary hyperparathyroidism is associated with arterial hypertension and an increased cardiovascular morbidity and mortality, which might be associated to higher aldosterone values; parathyreoidectomy results in lowered aldosterone and blood pressure levels. PA leads to secondary hyperparathyroidism, which is reversible by PA-directed therapy. A lower bone mineral density and a higher fracture rate were also shown to be reversible by PA-directed therapy. There is a suspicion of a bidirectional interaction between aldosterone and PTH, which might lead to a higher cardiovascular risk. There are more and more reports about coincident PA and primary hyperparathyroidism. From a pathophysiologic point of view this constellation is best characterized as tertiary hyperparathyroidism. Future aspects should further clarify the extent of these endocrine interactions and analyze the influence of this interplay on cardiovascular morbidity and mortality and bone health. © Georg Thieme Verlag KG Stuttgart · New York.

  4. Excess aldosterone-induced changes in insulin signaling molecules and glucose oxidation in gastrocnemius muscle of adult male rat.

    PubMed

    Selvaraj, Jayaraman; Sathish, Sampath; Mayilvanan, Chinnaiyan; Balasubramanian, Karundevi

    2013-01-01

    Emerging evidences demonstrate that excess aldosterone and insulin interact at target tissues. It has been shown that increased levels of aldosterone contribute to the development of insulin resistance and thus act as a risk factor for the development of type-2 diabetes mellitus. However, the molecular mechanisms involved in this scenario are yet to be identified. This study was designed to assess the dose-dependent effects of aldosterone on insulin signal transduction and glucose oxidation in the skeletal muscle (gastrocnemius) of adult male rat. Healthy adult male albino rats of Wistar strain (Rattus norvegicus) weighing 180-200 g were used in this study. Rats were divided into four groups. Group I: control (treated with 1 % ethanol only), group II: aldosterone treated (10 μg /kg body weight, twice daily for 15 days), group III: aldosterone treated (20 μg /kg body weight, twice daily for 15 days), and group IV: aldosterone treated (40 μg/kg body weight, twice daily for 15 days). Excess aldosterone caused glucose intolerance in a dose-dependent manner. Serum insulin and aldosterone were significantly increased, whereas serum testosterone was decreased. Aldosterone treatment impaired the rate of glucose uptake, oxidation, and insulin signal transduction in the gastrocnemius muscle through defective expression of IR, IRS-1, Akt, AS160, and GLUT4 genes. Phosphorylation of IRS-1, β-arrestin-2, and Akt was also reduced in a dose-dependent manner. Excess aldosterone results in glucose intolerance as a result of impaired insulin signal transduction leading to decreased glucose uptake and oxidation in skeletal muscle. In addition to this, it is inferred that excess aldosterone may act as one of the causative factors for the onset of insulin resistance and thus increased incidence of type-2 diabetes.

  5. Urinary renin, but not angiotensinogen or aldosterone, reflects the renal renin-angiotensin-aldosterone system activity and the efficacy of renin-angiotensin-aldosterone system blockade in the kidney.

    PubMed

    van den Heuvel, Mieke; Batenburg, Wendy W; Jainandunsing, Sjaam; Garrelds, Ingrid M; van Gool, Jeanette M G; Feelders, Richard A; van den Meiracker, Anton H; Danser, A H Jan

    2011-11-01

    To study which renin-angiotensin-aldosterone system (RAAS) component best reflects renal RAAS activity. We measured urinary and plasma renin, prorenin, angiotensinogen, aldosterone, albumin and creatinine in 101 diabetic and nondiabetic patients with or without hypertension. Plasma prorenin was elevated in diabetic patients. Urinary prorenin was undetectable. Urinary albumin and renin were higher in diabetic patients. Men had higher plasma renin/prorenin levels, and lower plasma angiotensinogen levels than women. Plasma creatinine and albumin were also higher in men. Urinary RAAS components showed no sexual dimorphism, whereas urinary creatinine and albumin were higher in men. Angiotensin-converting enzyme inhibitors and angiotensin II type 1 receptor blockers increased plasma renin and decreased plasma angiotensinogen, without altering plasma aldosterone. In contrast, in urine, these drugs decreased renin and aldosterone without affecting angiotensinogen. When analyzing all patients together, urinary angiotensinogen excretion closely mimicked that of albumin, whereas urinary angiotensinogen and albumin levels both were 0.05% or less of their concomitant plasma levels. This may reflect the identical glomerular filtration and tubular handling of both proteins, which have a comparable molecular weight. In contrast, urinary renin excretion did not correlate with urinary albumin excretion, and the urinary/plasma concentration ratio of renin was more than 200 times the ratio of albumin, despite its comparable molecular weight. Urinary aldosterone excretion closely followed urinary creatinine excretion. The increased urinary renin levels in diabetes and the decreased urinary renin levels following RAAS blockade, occurring independently of changes in plasma renin, reflect the activated renal RAAS in diabetes and the success of RAAS blockade in the kidney, respectively. Urinary renin, therefore, more closely reflects renal RAAS activity than urinary angiotensinogen or

  6. GPER is involved in the stimulatory effects of aldosterone in breast cancer cells and breast tumor-derived endothelial cells.

    PubMed

    Rigiracciolo, Damiano Cosimo; Scarpelli, Andrea; Lappano, Rosamaria; Pisano, Assunta; Santolla, Maria Francesca; Avino, Silvia; De Marco, Paola; Bussolati, Benedetta; Maggiolini, Marcello; De Francesco, Ernestina Marianna

    2016-01-05

    Aldosterone induces relevant effects binding to the mineralcorticoid receptor (MR), which acts as a ligand-gated transcription factor. Alternate mechanisms can mediate the action of aldosterone such as the activation of epidermal growth factor receptor (EGFR), MAPK/ERK, transcription factors and ion channels. The G-protein estrogen receptor (GPER) has been involved in the stimulatory effects of estrogenic signalling in breast cancer. GPER has been also shown to contribute to certain responses to aldosterone, however the role played by GPER and the molecular mechanisms implicated remain to be fully understood. Here, we evaluated the involvement of GPER in the stimulatory action exerted by aldosterone in breast cancer cells and breast tumor derived endothelial cells (B-TEC). Competition assays, gene expression and silencing studies, immunoblotting and immunofluorescence experiments, cell proliferation and migration were performed in order to provide novel insights into the role of GPER in the aldosterone-activated signalling. Our results demonstrate that aldosterone triggers the EGFR/ERK transduction pathway in a MR- and GPER-dependent manner. Aldosterone does not bind to GPER, it however induces the direct interaction between MR and GPER as well as between GPER and EGFR. Next, we ascertain that the up-regulation of the Na+/H+ exchanger-1 (NHE-1) induced by aldosterone involves MR and GPER. Biologically, both MR and GPER contribute to the proliferation and migration of breast and endothelial cancer cells mediated by NHE-1 upon aldosterone exposure. Our data further extend the current knowledge on the molecular mechanisms through which GPER may contribute to the stimulatory action elicited by aldosterone in breast cancer.

  7. Adrenal venous sampling in primary aldosteronism: multinomial regression modeling to detect aldosterone secretion lateralization when right adrenal sampling is missing.

    PubMed

    Durivage, Camille; Blanchette, Rémi; Soulez, Gilles; Chagnon, Miguel; Gilbert, Patrick; Giroux, Marie-France; Bourdeau, Isabelle; Oliva, Vincent L; Lacroix, André; Therasse, Eric

    2017-02-01

    Difficulty to recognize or canulate the right adrenal vein is the most frequent cause of adrenal venous sampling (AVS) failure. We aimed to assess multinomial regression modeling (MRM) of peripheral and left adrenal vein samplings to detect lateralization of aldosterone secretion when the right AVS is missing. Simultaneous bilateral AVS samplings were performed before (basal) and after intravenous cosyntropin injection in 188 consecutive patients between December 1989 and September 2015. Different reference standards for lateralization of aldosterone secretion were defined for basal and for postcosyntropin AVS and according to lateralization index cutoffs at least 2 and at least 4. MRMs were built to detect lateralization of aldosterone secretion according to these reference standards using only peripheral and left adrenal veins samplings (without the right AVS). Detection accuracy was assessed by the area under the receiver operating characteristic (AUROC) curves and detection sensitivities were reported for specificity at least 95%. For basal AVS with lateralization index at least 2, AUROC were respectively 0.931 [95% confidence interval (CI) 0.894-0.968] and 0.922 (95% CI 0.882-0.962) for right and left lateralization of aldosterone secretion detection and MRM could detect respectively 65.5 and 62.7% of the right and left lateralization of aldosterone secretion. For AVS after cosyntropin with lateralization index at least 4, AUROC were respectively 0.964 (95% CI: 0.940-0.987) and 0.955 (95% CI: 0.927-0.983) for right and left lateralization of aldosterone secretion, and MRM could detect respectively 77.2 and 72.9% of the right and left lateralization of aldosterone secretion. MRM can detect lateralization of aldosterone secretion without the right AVS in most patients and could eliminate the need for repeat AVS when right adrenal vein canulation is nonselective or impossible.

  8. Influence of gibberellin and daminozide on the expression of terpene synthases and on monoterpenes in common sage (Salvia officinalis).

    PubMed

    Schmiderer, Corinna; Grausgruber-Gröger, Sabine; Grassi, Paolo; Steinborn, Ralf; Novak, Johannes

    2010-07-01

    Common sage (Salvia officinalis L., Lamiaceae) is one of the most important medicinal and aromatic plants, with antioxidant, antimicrobial, spasmolytic, astringent, antihidrotic and specific sensorial properties. The essential oil of the plant, composed mainly of the monoterpenes 1,8-cineole, alpha-thujone, beta-thujone and camphor, is responsible for some of these effects. Gibberellins regulate diverse physiological processes in plants, such as seed germination, shoot elongation and cell division. In this study, we analyzed the effect of exogenously applied plant growth regulators, namely gibberellic acid (GA(3)) and daminozide, on leaf morphology and essential oil formation of two leaf stages during the period of leaf expansion. Essential oil content increased with increasing levels of gibberellins and decreased when gibberellin biosynthesis was blocked with daminozide. With increasing levels of gibberellins, 1,8-cineole and camphor contents increased. Daminozide blocked the accumulation of alpha- and beta-thujone. GA(3) at the highest level applied also led to a significant decrease of alpha- and beta-thujone. Monoterpene synthases are a class of enzymes responsible for the first step in monoterpene biosynthesis, competing for the same substrate geranylpyrophosphate. The levels of gene expression of the three most important monoterpene synthases in sage were investigated, 1,8-cineole synthase leading directly to 1,8-cineole, (+)-sabinene synthase responsible for the first step in the formation of alpha- and beta-thujone, and (+)-bornyl diphosphate synthase, the first step in camphor biosynthesis. The foliar application of GA(3) increased, while daminozide significantly decreased gene expression of the monoterpene synthases. The amounts of two of the end products, 1,8-cineole and camphor, were directly correlated with the levels of gene expression of the respective monoterpene synthases, indicating transcriptional control, while the formation of alpha- and beta

  9. Aldosterone response to angiotensin II during hypoxemia

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Colice, G.L.; Ramirez, G.

    1986-07-01

    Exercise stimulates the renin-angiotensin-aldosterone system (RAAS). However, increases in plasma aldosterone concentrations (PAC) are suppressed when exercise is performed at high altitude or under hypoxemic conditions. As the angiotensin-II response to high-altitude exercise is normal, it is speculated that an inhibitor, discharged during hypoxemia, acted to suppress angiotensin-II-mediated aldosterone release. A study was conducted to test this hypothesis, taking into account the measurement of the aldosterone response to exogenous angiotensin II during normoxemia and hypoxemia. It was found that the dose-response curve of PAC to angiotensin II was not significantly inhibited by the considered model of hypoxemia. The hypoxemia-mediated releasemore » of an angiotensin II inhibitor does, therefore, not explain the previous observations of PAC suppression during hypoxemic exercise. 28 references.« less

  10. Activity of [des-Aspartyl1]-Angiotensin II in Primary Aldosteronism

    PubMed Central

    Carey, Robert M.; Ayers, Carlos R.; Vaughan, E. Darracott; Peach, Michael J.; Herf, Steven M.

    1979-01-01

    This study describes the effects of [des-Aspartyl1]-angiotensin II ([des-Asp]-AII) on blood pressure and aldosterone production in patients with primary aldosteronism due to aldosterone-producing adrenal adenoma (APA) and idiopathic adrenal hyperplasia (IHA), and in normotensive control subjects. 10 patients with primary aldosteronism, 7 with APA and 3 with IHA, and 6 normotensive control subjects were placed on a constant 150-meq sodium diet for 4 days. [des-Asp]-AII was infused for 30 min at 6, 12, and 18 pmol/kg per min. Three groups of patients were identified on the basis of aldosterone response to [des-Asp]-AII. Group I, composed of normotensive control subjects, showed incremental increases in plasma aldosterone concentration from 6±1 to 14±3 ng/100 ml (P < 0.01) with [des-Asp]-AII infusion. Group II, composed of patients with primary aldosteronism, showed incremental increases in plasma aldosterone concentration from 33±8 to 65±13 ng/100 ml (P < 0.05) with 12 pmol/kg per min of [des-Asp]-AII. Group III, also composed of patients with primary aldosteronism, showed no increase of plasma aldosterone concentration with [des-Asp]-AII. Groups I and II showed similar percentage increases in plasma aldosterone concentration (P = NS). Group III showed significantly lower aldosterone responses than group I (P < 0.01). Group II included all patients with IHA and two patients with APA. Group III included only patients with APA. The blood pressure responses to [des-Asp]-AII of subjects in group I did not differ significantly from those of groups II or III. Thus, patients with IHA and a subgroup of patients with APA showed responsiveness to [des-Asp]-AII which was limited to adrenal cortical stimulation of aldosterone biosynthesis. This suggests that adrenal responsiveness to angiotensin is a major control mechanism in some forms of primary aldosteronism. The differential adrenal responsiveness to [des-Asp]-AII in patients with APA indicates either that there are two

  11. Aldosterone is associated with left ventricular hypertrophy in hemodialysis patients.

    PubMed

    Feniman De Stefano, Greicy Mara Mengue; Zanati-Basan, Silméia Garcia; De Stefano, Laercio Martins; Silva, Viviana Rugolo Oliveira E; Xavier, Patrícia Santi; Barretti, Pasqual; da Silva Franco, Roberto Jorge; Caramori, Jacqueline Costa Teixeira; Martin, Luis Cuadrado

    2016-10-01

    Patients with chronic kidney disease present a higher degree of left ventricular hypertrophy than expected for hypertension levels. In chronic kidney disease the plot between the quotient extracellular water/total body water and aldosterone is shifted up and to the right. There are few studies that verified the role of aldosterone in cardiac remodeling in this set of patients. The aim of this study was to evaluate the relationship between serum aldosterone and left ventricular mass index in patients with chronic kidney disease on hemodialysis. The patients were submitted to clinical and laboratory evaluation, bioelectrical impedance, echocardiography and ambulatory blood pressure monitoring. The 27 patients included were divided into two groups according to aldosterone level and compared with each other. The group of patients with higher aldosterone levels had higher left ventricular mass index. These groups were heterogeneous with regard to ambulatory systolic blood pressure, body mass index, and aldosterone levels and homogeneous with regard to the quotient extracellular water/total body water, renin-angiotensin-aldosterone system blockers, beta blocker use and other clinical characteristics. The association between aldosterone levels and left ventricular mass index was adjusted to confounding variables by a multiple linear regression analysis in which aldosterone was independently associated with left ventricular mass index. The data presented are consistent with a pathogenic role of aldosterone in left ventricular hypertrophy in patients with chronic kidney dialysis in dialysis patients. ClinicalTrials.gov identifier: NCT01128101. © The Author(s), 2016.

  12. Calcium-dependent mitochondrial cAMP production enhances aldosterone secretion.

    PubMed

    Katona, Dávid; Rajki, Anikó; Di Benedetto, Giulietta; Pozzan, Tullio; Spät, András

    2015-09-05

    Glomerulosa cells secrete aldosterone in response to agonists coupled to Ca(2+) increases such as angiotensin II and corticotrophin, coupled to a cAMP dependent pathway. A recently recognized interaction between Ca(2+) and cAMP is the Ca(2+)-induced cAMP formation in the mitochondrial matrix. Here we describe that soluble adenylyl cyclase (sAC) is expressed in H295R adrenocortical cells. Mitochondrial cAMP formation, monitored with a mitochondria-targeted fluorescent sensor (4mtH30), is enhanced by HCO3(-) and the Ca(2+) mobilizing agonist angiotensin II. The effect of angiotensin II is inhibited by 2-OHE, an inhibitor of sAC, and by RNA interference of sAC, but enhanced by an inhibitor of phosphodiesterase PDE2A. Heterologous expression of the Ca(2+) binding protein S100G within the mitochondrial matrix attenuates angiotensin II-induced mitochondrial cAMP formation. Inhibition and knockdown of sAC significantly reduce angiotensin II-induced aldosterone production. These data provide the first evidence for a cell-specific functional role of mitochondrial cAMP. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. MicroRNA-34b/c inhibits aldosterone-induced vascular smooth muscle cell calcification via a SATB2/Runx2 pathway.

    PubMed

    Hao, Jianbing; Zhang, Lei; Cong, Guangting; Ren, Liansheng; Hao, Lirong

    2016-12-01

    Increasing evidence shows that aldosterone and specific microRNAs (miRs) contribute to vascular smooth muscle cell (VSMC) calcification. In this study, we aim to explore the mechanistic links between miR-34b/c and aldosterone in VSMC calcification. VSMC calcification models were established both in vitro and in vivo. First, the levels of aldosterone, miR-34b/c and special AT-rich sequence-binding protein 2 (SATB2) were measured. Then, miR-34b/c mimics or inhibitors were transfected into VSMCs to evaluate the function of miR-34b/c. Luciferase reporter assays were used to demonstrate whether SATB2 was a direct target of miR-34b/c. Aldosterone and SATB2 were found to be markedly upregulated during VSMC calcification, whereas miR-34b/c expression was downregulated. Treatment with the mineralocorticoid receptor (MR) antagonist eplerenone inhibited VSMC calcification. In aldosterone-induced VSMC calcification, miR-34b/c levels were downregulated and SATB2 protein was upregulated. Furthermore, miR-34b/c overexpression alleviated aldosterone-induced VSMC calcification as well as inhibited the expression of SATB2 protein, whereas miR-34b/c inhibition markedly enhanced VSMC calcification and upregulated SATB2 protein. In addition, luciferase reporter assays showed that SATB2 is a direct target of miR-34b/c in VSMCs. Overexpression of SATB2 induced Runx2 overproduction and VSMC calcification. Therefore, miR-34b/c participates in aldosterone-induced VSMC calcification via a SATB2/Runx2 pathway. As miR-34b/c appears to be a negative regulator, it has potential as a therapeutic target of VSMC calcification.

  14. Specificity of Ocimum basilicum geraniol synthase modified by its expression in different heterologous systems.

    PubMed

    Fischer, Marc J C; Meyer, Sophie; Claudel, Patricia; Perrin, Mireille; Ginglinger, Jean François; Gertz, Claude; Masson, Jean E; Werck-Reinhardt, Danièle; Hugueney, Philippe; Karst, Francis

    2013-01-10

    Numerous aromatic plant species produce high levels of monoterpenols, using geranyl diphosphate (GPP) as a precursor. Sweet basil (Ocimum basilicum) geraniol synthase (GES) was used to evaluate the monoterpenol profiles arising from heterologous expressions in various plant models. Grapevine (Vitis vinifera) calli were transformed using Agrobacterium tumefasciens and the plants were regenerated. Thale cress (Arabidopsis thaliana) was transformed using the floral dip method. Tobacco (Nicotiana benthamiana) leaves were agro-infiltrated for transient expression. Although, as expected, geraniol was the main product detected in the leaves, different minor products were observed in these plants (V. vinifera: citronellol and nerol; N. benthamiana: linalool and nerol; A. thaliana: none). O. basilicum GES expression was also carried out with microbial system yeasts (Saccharomyces cerevisiae) and Escherichia coli. These results suggest that the functional properties of a monoterpenol synthase depend not only on the enzyme's amino-acidic sequence, but also on the cellular background. They also suggest that some plant species or microbial expression systems could induce the simultaneous formation of several carbocations, and could thus have a natural tendency to produce a wider spectrum of monoterpenols. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. GPER is involved in the stimulatory effects of aldosterone in breast cancer cells and breast tumor-derived endothelial cells

    PubMed Central

    Rigiracciolo, Damiano Cosimo; Scarpelli, Andrea; Lappano, Rosamaria; Pisano, Assunta; Santolla, Maria Francesca; Avino, Silvia; De Marco, Paola; Bussolati, Benedetta; Maggiolini, Marcello; De Francesco, Ernestina Marianna

    2016-01-01

    Aldosterone induces relevant effects binding to the mineralcorticoid receptor (MR), which acts as a ligand-gated transcription factor. Alternate mechanisms can mediate the action of aldosterone such as the activation of epidermal growth factor receptor (EGFR), MAPK/ERK, transcription factors and ion channels. The G-protein estrogen receptor (GPER) has been involved in the stimulatory effects of estrogenic signalling in breast cancer. GPER has been also shown to contribute to certain responses to aldosterone, however the role played by GPER and the molecular mechanisms implicated remain to be fully understood. Here, we evaluated the involvement of GPER in the stimulatory action exerted by aldosterone in breast cancer cells and breast tumor derived endothelial cells (B-TEC). Competition assays, gene expression and silencing studies, immunoblotting and immunofluorescence experiments, cell proliferation and migration were performed in order to provide novel insights into the role of GPER in the aldosterone-activated signalling. Our results demonstrate that aldosterone triggers the EGFR/ERK transduction pathway in a MR- and GPER-dependent manner. Aldosterone does not bind to GPER, it however induces the direct interaction between MR and GPER as well as between GPER and EGFR. Next, we ascertain that the up-regulation of the Na+/H+ exchanger-1 (NHE-1) induced by aldosterone involves MR and GPER. Biologically, both MR and GPER contribute to the proliferation and migration of breast and endothelial cancer cells mediated by NHE-1 upon aldosterone exposure. Our data further extend the current knowledge on the molecular mechanisms through which GPER may contribute to the stimulatory action elicited by aldosterone in breast cancer. PMID:26646587

  16. Latest aspects of aldosterone actions on the heart muscle.

    PubMed

    Kritis, A A; Gouta, C P; Liaretidou, E I; Kallaras, K I

    2016-02-01

    The genomic action of aldosterone has already been known to the scientific community and is well-documented to a satisfactory degree. However, the existence of rapid, non-genomic aldosterone actions has repeatedly been proven. These actions are apparent to a lot of tissues, among which the cardiac tissue, with the cardiac cells being responsible for the secretion of endogenous aldosterone. In the genomic pathway, the connection between the hormone and its receptor results increased reabsorption of sodium and water and excretion of potassium. Thus, the genomic procedure reacts indirectly on cardiovascular system by altering the blood pressure. New studies have shed light on unknown aspects of the non-genomic mechanism, which is sometimes performed by means of mineralocorticoid receptor (MR), while others through an MR-independent pathway. It is believed that aldosterone exerts its non-genomic action with the help of a different receptor, probably a G protein coupled receptor. A possible target is protein kinase C (PKC), and PKCε is postulated increase the permeability of the membrane of the cardiac cells to sodium, resulting in delayed repolarization and prolongation of action potential. These findings totally agree with and account for the serendipitous finding of our laboratory, that there is a positive correlation between plasma aldosterone levels and left ventricle (LV) contraction duration. Also, aldosterone has been proven to exacerbate the oxidative stress and induce vasoconstriction by acting on the vascular resistance and the cardiac output. Finally, this article deals with the role of aldosterone in cardiac fibrosis and the latest aspects of aldosterone actions on the heart muscle as well as providing a historical overview of the landmarks pertaining aldosterone's research.

  17. Prenatal diagnosis of Bartter syndrome: amniotic fluid aldosterone.

    PubMed

    Rachid, Myriam; Dreux, Sophie; Pean de Ponfilly, Gauthier; Vargas-Poussou, Rosa; Czerkiewicz, Isabelle; Chevenne, Didier; Oury, Jean-François; Deschênes, Georges; Muller, Françoise

    2017-04-01

    Bartter syndrome is a severe inherited tubulopathy characterized at birth by salt wasting, severe polyuria, dehydration, growth retardation and secondary hyperaldosteronism. Prenatally, the disease is usually discovered following onset of severe polyhydramnios. We studied amniotic fluid aldosterone concentration in cases of Bartter syndrome and in control groups. Amniotic fluid aldosterone was assayed by radioimmunoassay. We undertook a retrospective case-control study based on 36 cases of postnatally diagnosed Bartter syndrome and 144 controls matched for gestational age. Two controls groups were defined: controls with polyhydramnios (n=72) and control without polyhydramnios (n=72). Amniotic fluid aldosterone was compared between the three groups. The median amniotic fluid aldosterone concentration in the Bartter syndrome group (90 pg/mL) did not differ significantly from that in the controls with polyhydramnios (90 pg/mL, p=0.33) or the controls without polyhydramnios (87 pg/mL, p=0.41). In conclusion, amniotic fluid aldosterone assay cannot be used for prenatal diagnosis of Bartter syndrome.

  18. Global- and renal-specific sympathoinhibition in aldosterone hypertension.

    PubMed

    Lohmeier, Thomas E; Liu, Boshen; Hildebrandt, Drew A; Cates, Adam W; Georgakopoulos, Dimitrios; Irwin, Eric D

    2015-06-01

    Recent technology for chronic electric activation of the carotid baroreflex and renal nerve ablation provide global and renal-specific suppression of sympathetic activity, respectively, but the conditions for favorable antihypertensive responses in resistant hypertension are unclear. Because inappropriately high plasma levels of aldosterone are prevalent in these patients, we investigated the effects of baroreflex activation and surgical renal denervation in dogs with hypertension induced by chronic infusion of aldosterone (12 μg/kg per day). Under control conditions, basal values for mean arterial pressure and plasma norepinephrine concentration were 100±3 mm Hg and 134±26 pg/mL, respectively. By day 7 of baroreflex activation, plasma norepinephrine was reduced by ≈40% and arterial pressure by 16±2 mm Hg. All values returned to control levels during the recovery period. Arterial pressure increased to 122±5 mm Hg concomitant with a rise in plasma aldosterone concentration from 4.3±0.4 to 70.0±6.4 ng/dL after 14 days of aldosterone infusion, with no significant effect on plasma norepinephrine. After 7 days of baroreflex activation at control stimulation parameters, the reduction in plasma norepinephrine was similar but the fall in arterial pressure (7±1 mm Hg) was diminished (≈55%) during aldosterone hypertension when compared with control conditions. Despite sustained suppression of sympathetic activity, baroreflex activation did not have central actions to inhibit either the stimulation of vasopressin secretion or drinking induced by increased plasma osmolality during chronic aldosterone infusion. Finally, renal denervation did not attenuate aldosterone hypertension. These findings suggest that aldosterone excess may portend diminished blood pressure lowering to global and especially renal-specific sympathoinhibition during device-based therapy. © 2015 American Heart Association, Inc.

  19. Global and Renal-Specific Sympathoinhibition in Aldosterone Hypertension

    PubMed Central

    Lohmeier, Thomas E.; Liu, Boshen; Hildebrandt, Drew A.; Cates, Adam W.; Georgakopoulos, Dimitrios; Irwin, Eric D.

    2015-01-01

    Recent technology for chronic electrical activation of the carotid baroreflex and renal nerve ablation provide global and renal-specific suppression of sympathetic activity, respectively, but the conditions for favorable antihypertensive responses in resistant hypertension are unclear. Because inappropriately high plasma levels of aldosterone are prevalent in these patients, we investigated the effects of baroreflex activation and surgical renal denervation in dogs with hypertension induced by chronic infusion of aldosterone (12µg/kg/day). Under control conditions, basal values for mean arterial pressure and plasma norepinephrine concentration were 100±3 mm Hg and 134±26 pg/mL, respectively. By day 7 of baroreflex activation, plasma norepinephrine was reduced by ~ 40% and arterial pressure by 16±2 mmHg. All values returned to control levels during the recovery period. Arterial pressure increased to 122±5 mm Hg concomitant with a rise in plasma aldosterone concentration from 4.3±0.4 to 70.0±6.4 ng/dL after 14 days of aldosterone infusion, with no significant effect on plasma norepinephrine. After 7 days of baroreflex activation at control stimulation parameters, the reduction in plasma norepinephrine was similar but the fall in arterial pressure (7±1 mmHg) was diminished (~ 55%) during aldosterone hypertension as compared to control conditions. Despite sustained suppression of sympathetic activity, baroreflex activation did not have central actions to inhibit either the stimulation of vasopressin secretion or drinking induced by increased plasma osmolality during chronic aldosterone infusion. Finally, renal denervation did not attenuate aldosterone hypertension. These findings suggest that aldosterone excess may portend diminished blood pressure lowering to global and especially renal-specific sympathoinhibition during device-based therapy. PMID:25895584

  20. The Role of Aldosteronism in Causing Obesity-Related Cardiovascular Risk

    PubMed Central

    Calhoun, David A.; Sharma, Kumar

    2010-01-01

    Synopsis A large body of evidence strongly links aldosterone to development and progression of cardiovacscular disease, including vascular stiffness, left ventricular hypertrophy, congestive heart failure, chronic kidney disease, and especially, hypertension. Emerging data suggests that adipocytes may serve as a source of aldosterone, either directly, or indirectly, through release of aldosterone-stimulating factors. If adipocytes are confirmed to contribute importantly to hyperaldosteronism, it would have significant clinical implications in linking aldosterone to obesity-related increases in cardiovascular risk. Such a cause-and-effect would then provide the opportunity to reverse that risk with preferential use of aldosterone antagonists in obese patients. PMID:20621254

  1. Over-expression of a grape stilbene synthase gene in tomato induces parthenocarpy and causes abnormal pollen development.

    PubMed

    Ingrosso, Ilaria; Bonsegna, Stefania; De Domenico, Stefania; Laddomada, Barbara; Blando, Federica; Santino, Angelo; Giovinazzo, Giovanna

    2011-10-01

    A novel strategy to induce parthenocarpy in tomato fruits by the induction of resveratrol biosynthesis in flower tissues was exploited. Two transgenic tomato lines were considered: a higher resveratrol-producing (35SS) line, constitutively expressing a grape stilbene synthase cDNA, and a lower resveratrol-producing (LoxS) line, expressing stilbene synthase under a fruit-specific promoter. The expression of the stilbene synthase gene affected flavonoid metabolism in a different manner in the transgenic lines, and in one of these, the 35SS line, resulted in complete male sterility. Resveratrol was synthesised either in 35SS or LoxS tomato flowers, at an even higher extent (about 8-10 times) in the former line. We further investigated whether stilbene synthase expression may have resulted in impaired naringenin accumulation during flower development. In the 35SS flowers, naringenin was significantly impaired by about 50%, probably due to metabolic competition. Conversely, the amount of glycosylated flavonols increased in transgenic flowers, thereby excluding the diminished production of flavonols as a reason for parthenocarpy in tomato. We further investigated whether resveratrol synthesis may have resulted changes to pollen structure. Microscopic observations revealed the presence of few and abnormal flake-like pollen grains in 35SS flowers with no germination capability. Finally, the analysis of coumaric and ferulic acids, the precursors of lignin and sporopollenin biosynthesis, revealed significant depletion of these compounds, therefore suggesting an impairment in structural compounds as a reason for pollen ablation. These overall outcomes, to the best of our knowledge, reveal for the first time the major role displayed by resveratrol synthesis on parthenocarpy in tomato fruits. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  2. Interaction between nitric oxide and superoxide in the macula densa in aldosterone-induced alterations of tubuloglomerular feedback

    PubMed Central

    Zhang, Qian; Lin, Lin; Lu, Yan; Liu, Haifeng; Duan, Yanhua; Zhu, Xiaolong; Zou, Chengwei; Manning, R. Davis

    2013-01-01

    Tubuloglomerular feedback (TGF)-mediated constriction of the afferent arteriole is modulated by a balance between release of superoxide (O2−) and nitric oxide (NO) in macula densa (MD) cells. Aldosterone activates mineralocorticoid receptors that are expressed in the MD and induces both NO and O2− generation. We hypothesize that aldosterone enhances O2− production in the MD mediated by protein kinase C (PKC), which buffers the effect of NO in control of TGF response. Studies were performed in microdissected and perfused MD and in a MD cell line, MMDD1 cells. Aldosterone significantly enhanced O2− generation both in perfused MD and in MMDD1 cells. When aldosterone (10−7 mol/l) was added in the tubular perfusate, TGF response was reduced from 2.4 ± 0.3 μm to 1.4 ± 0.2 μm in isolated perfused MD. In the presence of tempol, a O2− scavenger, TGF response was 1.5 ± 0.2 μm. In the presence of both tempol and aldosterone in the tubular perfusate, TGF response was further reduced to 0.4 ± 0.2 μm. To determine if PKC is involved in aldosterone-induced O2− production, we exposed the O2− cells to a nonselective PKC inhibitor chelerythrine chloride, a specific PKCα inhibitor Go6976, or a PKCα siRNA, and the aldosterone-induced increase in O2− production was blocked. These data indicate that aldosterone-stimulated O2− production in the MD buffers the effect of NO in control of TGF response, an effect that was mediated by PKCα. PMID:23220724

  3. Sodium interference in the determination of urinary aldosterone.

    PubMed

    Aldea, Marta Lucía; Barallat, Jaume; Martín, María Amparo; Rosas, Irene; Pastor, María Cruz; Granada, María Luisa

    2016-02-01

    Primary hyperaldosteronism (PHA) is one of the most common endocrine forms of secondary hypertension. Among the most used confirmatory tests for PHA is urinary aldosterone determination after oral sodium loading test. The primary aim of our study was to investigate if sodium concentrations interfere with urinary aldosterone in an automated competitive immunoassay (Liaison®) as well as to verify the manufacturer's specifications. 24-hr urine samples were collected and stored frozen until assayed. Two pools at low and high aldosterone concentrations were prepared. Verification of performance for precision was tested according to Clinical and Laboratory Standards Institute (CLSI) document EP15-A2 and interference with increasing concentrations of NaCl according to CLSI EP7-A2. The assay met the quality specifications according to optimal biological variation. Our results show that sodium concentrations up to 200mmol/L do not interfere on urinary aldosterone quantification, but sodium concentrations above 486mmol/L negatively interfere with the test. The Liaison® automated method is useful for aldosterone determination in the PHA confirmatory test, but interferences with NaCl may occur. It is therefore recommended to determine urinary NaCl before measuring urinary aldosterone to avoid falsely low results. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  4. Clinical characteristics of aldosterone-producing microadenoma, macroadenoma, and idiopathic hyperaldosteronism in 93 patients with primary aldosteronism.

    PubMed

    Omura, Masao; Sasano, Hironobu; Saito, Jun; Yamaguchi, Kunio; Kakuta, Yukio; Nishikawa, Tetsuo

    2006-11-01

    Primary aldosteronism (PA) due to aldosterone-producing adenoma (APA) is a form of surgically curable secondary hypertension, and distinguishing APA from idiopathic hyperaldosteronism (IHA) is important for treatment. We made a differential diagnosis between APA and IHA using imaging tests such as adrenal CT and MRI as well as adrenal venous sampling (AVS) in all 93 cases of PA presenting at our institutions over the last decade. We identified 27 patients with aldosterone-producing microadenoma (APmicroA), all of whom could be diagnosed by AVS but not by the imaging tests. Then, we compared the clinical and roent-genological findings of these 27 patients with those of 42 patients with aldosterone-producing macroadenoma (APmacroA) and of 24 patients with IHA. Using surgically removed adrenal tissues, histopathological examinations and immunohistochemical analyses of steroidogenic enzymes were conducted. The findings for APmicroA were similar to those for APmacroA, except with respect to the diameter of the adrenal adenomas. Endocrinological and roentgenological findings for APmicroA were similar to those for IHA, but not to those for APmacroA. The rate of cure of hypertension was much greater in patients with APmicroA than in patients with APmacroA after the unilateral adrenalectomy (odds ratio, 4.0; p=0.028). In conclusion, it is important to accurately diagnose APmicroA, in which the laterality of the hyperproduction of aldosterone is only detectable by AVS, and to treat these patients by unilateral adrenalectomy in order to avoid long-term medical treatment and prevent hypertensive vascular complications.

  5. Aldosterone induces fibrosis, oxidative stress and DNA damage in livers of male rats independent of blood pressure changes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Queisser, Nina; Happ, Kathrin; Link, Samuel

    Mineralocorticoid receptor blockers show antifibrotic potential in hepatic fibrosis. The mechanism of this protective effect is not known yet, although reactive oxygen species seem to play an important role. Here, we investigated the effects of elevated levels of aldosterone (Ald), the primary ligand of the mineralocorticoid receptor, on livers of rats in a hyperaldosteronism model: aldosterone-induced hypertension. Male Sprague–Dawley rats were treated for 4 weeks with aldosterone. To distinguish if damage caused in the liver depended on increased blood pressure or on increased Ald levels, the mineralocorticoid receptor antagonist spironolactone was given in a subtherapeutic dose, not normalizing blood pressure.more » To investigate the impact of oxidative stress, the antioxidant tempol was administered. Aldosterone induced fibrosis, detected histopathologically, and by expression analysis of the fibrosis marker, α-smooth muscle actin. Further, the mRNA amount of the profibrotic cytokine TGF-β was increased significantly. Fibrosis could be reduced by scavenging reactive oxygen species, and also by blocking the mineralocorticoid receptor. Furthermore, aldosterone treatment caused oxidative stress and DNA double strand breaks in livers, as well as the elevation of DNA repair activity. An increase of the transcription factor Nrf2, the main regulator of the antioxidative response could be observed, and of its target genes heme oxygenase-1 and γ-glutamylcysteine synthetase. All these effects of aldosterone were prevented by spironolactone and tempol. Already after 4 weeks of treatment, aldosteroneinfusion induced fibrosis in the liver. This effect was independent of elevated blood pressure. DNA damage caused by aldosterone might contribute to fibrosis progression when aldosterone is chronically increased. - Highlights: • Aldosterone has direct profibrotic effects on the liver independent of blood pressure. • Fibrosis is mediated by the mineralocorticoid

  6. Therapeutic effect of enhancing endothelial nitric oxide synthase (eNOS) expression and preventing eNOS uncoupling

    PubMed Central

    Förstermann, Ulrich; Li, Huige

    2011-01-01

    Nitric oxide (NO) produced by the endothelium is an important protective molecule in the vasculature. It is generated by the enzyme endothelial NO synthase (eNOS). Similar to all NOS isoforms, functional eNOS transfers electrons from nicotinamide adenine dinucleotide phosphate (NADPH), via the flavins flavin adenine dinucleotide and flavin mononucleotide in the carboxy-terminal reductase domain, to the heme in the amino-terminal oxygenase domain. Here, the substrate L-arginine is oxidized to L-citrulline and NO. Cardiovascular risk factors such as diabetes mellitus, hypertension, hypercholesterolaemia or cigarette smoking reduce bioactive NO. These risk factors lead to an enhanced production of reactive oxygen species (ROS) in the vessel wall. NADPH oxidases represent major sources of this ROS and have been found upregulated in the presence of cardiovascular risk factors. NADPH-oxidase-derived superoxide avidly reacts with eNOS-derived NO to form peroxynitrite (ONOO-). The essential NOS cofactor (6R-)5,6,7,8-tetrahydrobiopterin (BH4) is highly sensitive to oxidation by this ONOO-. In BH4 deficiency, oxygen reduction uncouples from NO synthesis, thereby converting NOS to a superoxide-producing enzyme. Among conventional drugs, compounds interfering with the renin-angiotensin-aldosterone system and statins can reduce vascular oxidative stress and increase bioactive NO. In recent years, we have identified a number of small molecules that have the potential to prevent eNOS uncoupling and, at the same time, enhance eNOS expression. These include the protein kinase C inhibitor midostaurin, the pentacyclic triterpenoids ursolic acid and betulinic acid, the eNOS enhancing compounds AVE9488 and AVE3085, and the polyphenolic phytoalexin trans-resveratrol. Such compounds enhance NO production from eNOS also under pathophysiological conditions and may thus have therapeutic potential. PMID:21198553

  7. A marked proportional rise in IVC aldosterone following cosyntropin administration during AVS is a signal to the presence of adrenal hyperplasia in primary aldosteronism.

    PubMed

    Kline, G A; Pasieka, J L; Harvey, A; So, B; Dias, V C

    2014-05-01

    We hypothesized aldosteronoma responsiveness to cosyntropin may be a characterizing feature that could be determined in addition to standard adrenal vein sampling (AVS) data. We reviewed an AVS database from June 2005 to October 2011 including 65 patients with confirmed primary aldosteronism (PA) who underwent AVS and, if applicable, unilateral adrenalectomy. Patients were divided into confirmed lateralized and non-lateralized groups and subgrouped by histology. Plasma aldosterone in inferior vena cava (IVC) pre- and post-cosyntropin infusion during AVS was measured. Peak aldosterone and proportional change was compared between groups. Baseline and peak IVC aldosterone was higher in lateralized patients but incremental aldosterone rise was much greater in subjects with bilateral hyperplasia. From receiver operator characteristics (ROC) analysis, the optimized diagnostic cut point of peak IVC aldosterone of >649 pmol l(-1) would have a sensitivity of 94% for surgical disease although specificity of just 59%. A 250% increase in IVC aldosterone following cosyntropin would be specific enough to exclude 87% of surgical/lateralized disease. These diagnostic capabilities are similar to other results with non-AVS tests performed for diagnosis of lateralization. Although not specific enough to replace standard AVS interpretation, a marked IVC aldosterone increase after cosyntropin during AVS is a useful additional test to diagnose non-lateralizing forms of PA. Such a calculation requires no additional expense or tests.

  8. In Utero Exposure to the Antiandrogen Di-(2-Ethylhexyl) Phthalate Decreases Adrenal Aldosterone Production in the Adult Rat1

    PubMed Central

    Martinez-Arguelles, Daniel B.; Guichard, Theodore; Culty, Martine; Zirkin, Barry R.; Papadopoulos, Vassilios

    2011-01-01

    We previously reported that in utero exposure of the male fetus to the plasticizer di-(2-ethylhexyl) phthalate (DEHP) resulted in decreased circulating levels of testosterone in the adult without affecting Leydig cell numbers, luteinizing hormone levels, or steroidogenic enzyme expression. Fetal exposure to DEHP resulted in reduced mineralocorticoid receptor (MR; NR3C2) expression in adult Leydig cells. In the present studies, treatment of pregnant Sprague-Dawley dams from Gestational Day 14 until birth with 20, 50, 100, 300, or 750 mg kg−1 day−1 of DEHP resulted in significant sex-specific decreases in serum aldosterone but not corticosterone levels at Postnatal Day 60 (PND60) but not at PND21. There was no effect on circulating levels of potassium, angiotensin II or adrenocorticotropin hormone (ACTH). However, there was reduced expression of AT receptor Agtr1a, Agtr1b, and Agtr2 mRNAs. The mRNA levels of proteins and enzymes implicated in aldosterone biosynthesis were not affected by in utero DEHP treatment except for Cyp11b2, which was decreased at high (≥500 mg kg−1 day−1) doses. The data presented herein, together with our previous observation that aldosterone stimulates testosterone production via an MR-mediated mechanism, suggest that in utero exposure to DEHP causes reduction in both adrenal aldosterone synthesis and MR expression in Leydig cells, leading to reduced testosterone production in the adult. Moreover, these results suggest the existence of a DEHP-sensitive adrenal-testis axis regulating androgen formation. PMID:21389346

  9. Enzyme-linked immunosorbent assays for determination of plasma aldosterone using highly specific polyclonal antibodies.

    PubMed

    Schwartz, F; Hadas, E; Harnik, M; Solomon, B

    1990-01-01

    Two enzyme-linked immunosorbent assays were established and compared for the estimation of plasma aldosterone. In the first method immobilized aldosterone-protein complexes on the ELISA plates compete with aldosterone to be determined for the binding of certain amount of anti-aldosterone antibodies. The sensitivity of this method depends on the protein carrier used to conjugate with aldosterone. In the second method, anti-aldosterone antibodies adsorbed on ELISA plates compete for binding of known amount of the enzyme-labeled aldosterone and aldosterone to be determined. The highly specific rabbit anti-aldosterone antibodies were obtained by injection of aldosterone-oxime thyroglobulin. The detection limit of aldosterone in both methods ranged between 2-20 pg. The proposed assays are suitable for the determination of aldosterone in biological fluids compared with other reported ELISA assays, as well as with RIA.

  10. Macrolides Blunt Aldosterone Biosynthesis: A Proof-of-Concept Study in KCNJ5 Mutated Adenoma Cells Ex Vivo.

    PubMed

    Caroccia, Brasilina; Prisco, Selene; Seccia, Teresa Maria; Piazza, Maria; Maiolino, Giuseppe; Rossi, Gian Paolo

    2017-12-01

    Aldosterone-producing adenoma (APA), a major subtype of primary hyperaldosteronism, the main curable cause of human endocrine hypertension, involves somatic mutations in the potassium channel Kir3.4 ( KCNJ5 ) in 30% to 70% of cases, typically the more florid phenotypes. Because KCNJ5 mutated channels were reported to be specifically sensitive to inhibition by macrolide antibiotics, which concentration dependently blunts aldosterone production in HAC15 transfected with the G151R and L168R mutated channel, we herein tested the effect of clarithromycin on aldosterone synthesis and secretion in a pure population of aldosterone-secreting cells obtained by immunoseparation (CD56 + cells) from APA tissues with/without the 2 most common KCNJ5 mutations. From a large cohort of patients with an unambiguous APA diagnosis, we recruited those who were wild type (n=3) or had G151R (n=2) and L168R (n=2) mutations. We found that clarithromycin concentration dependently lowered CYP11B2 gene expression (by 60%) and aldosterone secretion (by 70%; P <0.001 for both) in CD56 + cells isolated ex vivo from KCNJ5 mutated APAs, although it was ineffective in CD56 + cells from wild-type APAs. By proving the principle that the oversecretion of aldosterone can be specifically blunted in APA cells ex vivo with G151R and L168R mutations, these results provide compelling evidence of the possibility of specifically correcting aldosterone excess in patients with APA carrying the 2 most common KCNJ5 somatic mutations. © 2017 American Heart Association, Inc.

  11. Prenatal diagnosis of Bartter syndrome: amniotic fluid aldosterone.

    PubMed

    Rachid, Myriam L; Dreux, Sophie; Pean de Ponfilly, Gauthier; Vargas-Poussou, Rosa; Czerkiewicz, Isabelle; Chevenne, Didier; Oury, Jean-François; Deschênes, Georges; Muller, Françoise

    2016-01-01

    Bartter syndrome is a severe inherited tubulopathy characterized by postnatal salt wasting, severe polyuria, dehydration, failure to thrive and secondary hyperaldosteronism. Prenatally, the disease is usually discovered following the onset of severe polyhydramnios in the second trimester. We studied amniotic fluid aldosterone concentration in Bartter syndrome and in controls. Amniotic fluid aldosterone was assayed by radioimmunoassay. We undertook a retrospective case-control study based on 36 cases of prenatally suspected and postnatally confirmed Bartter syndrome (22 with identified mutations): and 72 gestational age matched controls presenting with polyhydramnios and 72 without polyhydramnios. Amniotic fluid aldosterone was compared between the three groups. The median amniotic fluid aldosterone concentration in the Bartter syndrome group (90 pg/mL) was not different from that in the controls with polyhydramnios (90 pg/mL, P = 0.33) or without polyhydramnios (87 pg/mL, P = 0.41). Amniotic fluid aldosterone assay cannot be used for prenatal diagnosis of Bartter syndrome. © 2015 John Wiley & Sons, Ltd. © 2015 John Wiley & Sons, Ltd.

  12. Role of radiology in the management of primary aldosteronism.

    PubMed

    Patel, Shilpan M; Lingam, Ravi K; Beaconsfield, Tina I; Tran, Tan L; Brown, Beata

    2007-01-01

    The diagnosis of primary aldosteronism, the most common form of secondary hypertension, is based on clinical and biochemical features. Although radiology plays no role in the initial diagnosis, it has an important role in differentiating between the two main causes of primary aldosteronism: aldosterone-producing adenoma (APA) and bilateral adrenal hyperplasia (BAH). This distinction is important because APAs are generally managed surgically and BAH medically. Adrenal venous sampling is considered the standard of reference for determining the cause of primary aldosteronism but is technically demanding, operator dependent, costly, and time consuming, with a low but significant complication rate. Other imaging modalities, including computed tomography, magnetic resonance imaging, and adrenal scintigraphy, have also been used to determine the cause of primary aldosteronism. Cross-sectional imaging has traditionally focused on establishing the diagnosis of an APA, with that of BAH being one of exclusion. A high specificity for detecting an APA is desirable, since it will avert unnecessary surgery in patients with BAH. However, an overreliance on cross-sectional imaging can lead to the incorrect treatment of affected patients, mainly due to the wide variation in the reported diagnostic performance of these modalities. A combination of modalities is usually required to confidently determine the cause of primary aldosteronism. The quest for optimal radiologic management of primary aldosteronism continues just over a half century since this disease entity was first described. RSNA, 2007

  13. Resistant hypertension and aldosterone: an update.

    PubMed

    Clark, Donald; Ahmed, Mustafa I; Calhoun, David A

    2012-05-01

    Resistant hypertension (RHTN) is defined as a blood pressure remaining above goal despite the concurrent use of 3 antihypertensive medications of different classes, including, ideally a diuretic. RHTN is an important health problem with a prevalence rate expected to increase as populations become older, more obese, and at higher risk of having diabetes and chronic kidney disease, all of which are important risk factors for development of RHTN. The role of aldosterone has gained increasing recognition as a significant contributor to antihypertensive treatment resistance. In prospective studies, the prevalence of primary aldosteronism (PA) has ranged from 14%-21% in patients with RHTN, which is considerably higher than in the general hypertensive population. Furthermore, marked antihypertensive effects are seen when mineralocorticoid antagonists are added to the treatment regimen of patients with RHTN, further supporting aldosterone excess as an important cause of RHTN. A close association exists between hyperaldosteronism, RHTN, and obstructive sleep apnea (OSA) based upon recent studies which indicate that OSA is worsened by aldosterone-mediated fluid retention. This interaction is supported by preliminary data which demonstrates improvement in OSA severity after treatment with spironolactone. Copyright © 2012 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  14. RNA-Seq in the discovery of a sparsely expressed scent-determining monoterpene synthase in lavender (Lavandula).

    PubMed

    Adal, Ayelign M; Sarker, Lukman S; Malli, Radesh P N; Liang, Ping; Mahmoud, Soheil S

    2018-06-09

    Using RNA-Seq, we cloned and characterized a unique monoterpene synthase responsible for the formation of a scent-determining S-linalool constituent of lavender oils from Lavandula × intermedia. Several species of Lavandula produce essential oils (EOs) consisting mainly of monoterpenes including linalool, one of the most abundant and scent-determining oil constituents. Although R-linalool dominates the EOs of lavenders, varying amounts (depending on the species) of the S-linalool enantiomer can also be found in these plants. Despite its relatively low abundance, S-linalool contributes a sweet, pleasant scent and is an important constituent of lavender EOs. While several terpene synthase genes including R-linalool synthase have been cloned from lavenders many important terpene synthases including S-linalool synthase have not been described from these plants. In this study, we employed RNA-Seq and other complementary sequencing data to clone and functionally characterize the sparsely expressed S-linalool synthase cDNA (LiS-LINS) from Lavandula × intermedia. Recombinant LiS-LINS catalyzed the conversion of the universal monoterpene precursor geranyl diphosphate to S-linalool as the sole product. Intriguingly, LiS-LINS exhibited very low (~ 30%) sequence similarity to other Lavandula terpene synthases, including R-linalool synthase. However, the predicted 3D structure of this protein, including the composition and arrangement of amino acids at the active site, is highly homologous to known terpene synthase proteins. LiS-LINS transcripts were detected in flowers, but were much less abundant than those corresponding to LiR-LINS, paralleling enantiomeric composition of linalool in L. × intermedia oils. These data indicate that production of S-linalool is at least partially controlled at the level of transcription from LiS-LINS. The cloned LiS-LINS cDNA may be used to enhance oil composition in lavenders and other plants through metabolic engineering.

  15. New agents modulating the renin-angiotensin-aldosterone system—Will there be a new therapeutic option?

    PubMed Central

    Szoka, Piotr; Kolodziejczyk, Patrycjusz; Kramkowski, Karol; Wojewodzka-Zelezniakowicz, Marzena; Chabielska, Ewa

    2016-01-01

    The renin-angiotensin-aldosterone system (RAAS) is more complex than it was originally regarded. According to the current subject knowledge, there are two main axes of the RAAS: (1) angiotensin-converting enzyme (ACE)-angiotensin II-AT1 receptor axis and (2) ACE2-angiotensin-(1-7)-Mas receptor axis. The activation of the first axis leads to deleterious effects, including vasoconstriction, endothelial dysfunction, thrombosis, inflammation, and fibrosis; therefore, blocking the components of this axis is a highly rational and commonly used therapeutic procedure. The ACE2-Ang-(1-7)-Mas receptor axis has a different role, since it often opposes the effects induced by the classical ACE-Ang II-AT1 axis. Once the positive effects of the ACE2-Ang-(1-7)-Mas axis were discovered, the alternative ways of pharmacotherapy activating this axis of RAAS appeared. This article briefly describes new molecules affecting the RAAS, namely: recombinant human ACE2, ACE2 activators, angiotensin-(1-7) peptide and non-peptide analogs, aldosterone synthase inhibitors, and the third and fourth generation of mineralocorticoid receptor antagonists. The results of the experimental and clinical studies are encouraging, which leads us to believe that these new molecules can support the treatment of cardiovascular diseases as well as cardiometabolic disorders. PMID:27439538

  16. Relation of plasma aldosterone concentration to diuretic treatment in patients with severe heart disease.

    PubMed Central

    Knight, R K; Miall, P A; Hawkins, L A; Dacombe, J; Edwards, C R; Hamer, J

    1979-01-01

    To assess the relation of hyperaldosteronism and potassium depletion to the intensity of diuretic therapy we have measured plasma aldosterone by radioimmunoassay and total exchangeable potassium by radioisotope dilution in 24 patients when they were stable at the end of their preparation for cardiac operation. Some patients required intensive frusemide therapy to reach an optimal state for operation and many showed hyperaldosteronism. Plasma aldosterone was significantly related to daily dose of frusemide (r=0.77). Depletion of total exchangeable potassium expressed in terms of predicted weight was significantly related to plasma aldosterone (r= -0.64). The reduction in total exchangeable potassium is interpreted as chiefly related to loss of lean tissue mass from the wasting that leads to cardiac cachexia, but evidence is presented on the basis of measurements of extracellular fluid volume as sulphate space (20 patients) of entry of sodium into the cells which may indicate a true cellular potassium loss. Although plasma potassium is usually easily maintained with oral potassium supplements or aldosterone antagonists, we postulate that intensive diuretic therapy in severe heart disease may provoke hyperaldosteronism which accentuates potassium loss and may contribute to wasting and to intracellular potassium depletion in critical tissue, such as myocardium. PMID:508454

  17. Aldosterone, Cognitive Function, and Cerebral Hemodynamics in Hypertension and Antihypertensive Therapy

    PubMed Central

    Hart, Meaghan; Mack, Wendy; Lipsitz, Lewis A.

    2015-01-01

    BACKGROUND Animal studies suggest that the renin–angiotensin–aldosterone system is involved in neurocognitive function and the response to antihypertensive therapy. We investigated the impact of circulating aldosterone and renin activity on cognition and cerebral hemodynamics at baseline and after antihypertensive therapy for 1 year. METHODS Participants were older adults (n = 47; mean age = 71 years) enrolled in a clinical trial. Routine antihypertensive medications were replaced with the study regimen to achieve a blood pressure <140/90mm Hg. Executive function, memory, cerebral hemodynamics (blood flow velocity), CO2 vasoreactivity (measured using transcranial Doppler ultrasonography), plasma renin activity, and aldosterone were measured at baseline and at 6 and 12 months after the initiation of treatment. RESULTS At baseline, higher levels of circulating aldosterone were associated with lower blood flow velocity (β = −0.02; P = 0.03), lower CO2 vasoreactivity (β = −0.11; P = 0.007), and decreased autoregulation abilities (β = −0.09; P = 0.01). Those with higher levels of aldosterone at baseline demonstrated the greatest improvement in executive function (P = 0.014 for the aldosterone effect) and in CO2 vasoreactivity (P = 0.026 for the aldosterone effect) after 12 months of lowering blood pressure (<140/90mm Hg). Plasma renin activity was not associated with any of the measures. CONCLUSIONS Higher levels of aldosterone may be associated with decreased cerebrovascular function in hypertension. Those with higher aldosterone levels may benefit the most from lowering blood pressure. The role of aldosterone in brain health warrants further investigation in a larger trial. PMID:25213687

  18. Aldosterone and mortality in hemodialysis patients: role of volume overload.

    PubMed

    Hung, Szu-Chun; Lin, Yao-Ping; Huang, Hsin-Lei; Pu, Hsiao-Fung; Tarng, Der-Cherng

    2013-01-01

    Elevated aldosterone is associated with increased mortality in the general population. In patients on dialysis, however, the association is reversed. This paradox may be explained by volume overload, which is associated with lower aldosterone and higher mortality. We evaluated the relationship between aldosterone and outcomes in a prospective cohort of 328 hemodialysis patients stratified by the presence or absence of volume overload (defined as extracellular water/total body water >48%, as measured with bioimpedance). Baseline plasma aldosterone was measured before dialysis and categorized as low (<140 pg/mL), middle (140 to 280 pg/mL) and high (>280 pg/mL). Overall, 36% (n = 119) of the hemodialysis patients had evidence of volume overload. Baseline aldosterone was significantly lower in the presence of volume overload than in its absence. During a median follow-up of 54 months, 83 deaths and 70 cardiovascular events occurred. Cox multivariate analysis showed that by using the low aldosterone as the reference, high aldosterone was inversely associated with decreased hazard ratios for mortality (0.49; 95% confidence interval, 0.25-0.76) and first cardiovascular event (0.70; 95% confidence interval, 0.33-0.78) in the presence of volume overload. In contrast, high aldosterone was associated with an increased risk for mortality (1.97; 95% confidence interval, 1.69-3.75) and first cardiovascular event (2.01; 95% confidence interval, 1.28-4.15) in the absence of volume overload. The inverse association of aldosterone with adverse outcomes in hemodialysis patients is due to the confounding effect of volume overload. These findings support treatment of hyperaldosteronemia in hemodialysis patients who have achieved strict volume control.

  19. Retinal vasculopathy is reduced by dietary salt restriction: involvement of Glia, ENaCα, and the renin-angiotensin-aldosterone system.

    PubMed

    Deliyanti, Devy; Armani, Roksana; Casely, David; Figgett, William A; Agrotis, Alex; Wilkinson-Berka, Jennifer L

    2014-09-01

    Neovascularization and vaso-obliteration are vision-threatening events that develop by interactions between retinal vascular and glial cells. A high-salt diet is causal in cardiovascular and renal disease, which is linked to modulation of the renin-angiotensin-aldosterone system. However, it is not known whether dietary salt influences retinal vasculopathy and if the renin-angiotensin-aldosterone system is involved. We examined whether a low-salt (LS) diet influenced vascular and glial cell injury and the renin-angiotensin-aldosterone system in ischemic retinopathy. Pregnant Sprague Dawley rats were fed LS (0.03% NaCl) or normal salt (0.3% NaCl) diets, and ischemic retinopathy was induced in the offspring. An LS diet reduced retinal neovascularization and vaso-obliteration, the mRNA and protein levels of the angiogenic factors, vascular endothelial growth factor, and erythropoietin. Microglia, which influence vascular remodeling in ischemic retinopathy, were reduced by LS as was tumor necrosis factor-α. Macroglial Müller cells maintain the integrity of the blood-retinal barrier, and in ischemic retinopathy, LS reduced their gliosis and also vascular leakage. In retina, LS reduced mineralocorticoid receptor, angiotensin type 1 receptor, and renin mRNA levels, whereas, as expected, plasma levels of aldosterone and renin were increased. The aldosterone/mineralocorticoid receptor-sensitive epithelial sodium channel alpha (ENaCα), which is expressed in Müller cells, was increased in ischemic retinopathy and reduced by LS. In cultured Müller cells, high salt increased ENaCα, which was prevented by mineralocorticoid receptor and angiotensin type 1 receptor blockade. Conversely, LS reduced ENaCα, angiotensin type 1 receptor, and mineralocorticoid receptor expression. An LS diet reduced retinal vasculopathy, by modulating glial cell function and the retinal renin-angiotensin-aldosterone system. © 2014 American Heart Association, Inc.

  20. Differential proteomics reveals S100-A11 as a key factor in aldosterone-induced collagen expression in human cardiac fibroblasts.

    PubMed

    Martínez-Martínez, Ernesto; Ibarrola, Jaime; Lachén-Montes, Mercedes; Fernández-Celis, Amaya; Jaisser, Frederic; Santamaría, Enrique; Fernández-Irigoyen, Joaquín; López-Andrés, Natalia

    2017-08-23

    Aldosterone (Aldo) could induce cardiac fibrosis, a hallmark of heart disease. Aldo direct effects on collagen production in cardiac fibroblasts remain controversial. Our aim is to characterize changes in the proteome of adult human cardiac fibroblasts treated with Aldo to identify new proteins altered that might be new therapeutic targets in cardiovascular diseases. Aldo increased collagens expressions in human cardiac fibroblasts. Complementary, using a quantitative proteomic approach, 30 proteins were found differentially expressed between control and Aldo-treated cardiac fibroblasts. Among these proteins, 7 were up-regulated and 23 were down-regulated by Aldo. From the up-regulated proteins, collagen type I, collagen type III, collagen type VI and S100-A11 were verified by Western blot. Moreover, protein interaction networks revealed a functional link between a third of Aldo-modulated proteome and specific survival routes. S100-A11 was identified as a possible link between Aldo and collagen. Interestingly, CRISPR/Cas9-mediated knock-down of S100-A11 blocked Aldo-induced collagen production in human cardiac fibroblasts. In adult human cardiac fibroblasts treated with Aldo, proteomic analyses revealed an increase in collagen production. S100-A11 was identified as a new regulator of Aldo-induced collagen production in human cardiac fibroblasts. These data could identify new candidate proteins for the treatment of cardiac fibrosis in cardiovascular diseases. S100-A11 is identified by a proteomic approach as a novel regulator of Aldosterone-induced collagen production in human cardiac fibroblasts. Our data could identify new candidate proteins of interest for the treatment of cardiac fibrosis in cardiovascular diseases. Copyright © 2017. Published by Elsevier B.V.

  1. Circulating aldosterone induces the apical accumulation of the proton pumping V-ATPase and increases proton secretion in clear cells in the caput epididymis.

    PubMed

    Roy, Jeremy W; Hill, Eric; Ruan, Ye Chun; Vedovelli, Luca; Păunescu, Teodor G; Brown, Dennis; Breton, Sylvie

    2013-08-15

    Clear cells express the vacuolar proton-pumping H(+)-ATPase (V-ATPase) and acidify the lumen of the epididymis, a process that is essential for male fertility. The renin-angiotensin-aldosterone system (RAAS) regulates fluid and electrolyte balance in the epididymis, and a previous study showed binding of aldosterone exclusively to epididymal clear cells (Hinton BT, Keefer DA. Steroid Biochem 23: 231-233, 1985). We examined here the role of aldosterone in the regulation of V-ATPase in the epididymis. RT-PCR showed expression of the mineralocorticoid receptor [MR; nuclear receptor subfamily 3, group C member 2 (NR3C2)] and 11-β-dehydrogenase isozyme 2 (HSD11β2) mRNAs specifically in clear cells, isolated by fluorescence-activated cell sorting from B1-enhanced green fluorescent protein (EGFP) mice. Tail vein injection of adult rats with aldosterone, 1,2-dioctanoyl-sn-glycerol (DOG), or 8-(4-chlorophenylthio)-cAMP (cpt-cAMP) induced V-ATPase apical membrane accumulation and extension of V-ATPase-labeled microvilli in clear cells in the caput epididymis but not in the cauda. V-ATPase activity was measured in EGFP-expressing clear cells using the intracellular pH (pHi)-sensing dye seminaphthorhodafluor-5F-5-(and 6)-carboxylic acid, acetoxymethyl ester acetate (SNARF-5F). Aldosterone induced a rapid increase in the rate of Na(+)- and bicarbonate-independent pHi recovery following an NH4Cl-induced acid load in clear cells isolated from the caput but not the cauda. This effect was abolished by concanamycin A, spironolactone, and chelerythrine but not myristoylated-protein kinase inhibitor (mPKI) or mifepristone. Thus aldosterone increases V-ATPase-dependent proton secretion in clear cells in the caput epididymis via MR/NR3C2 and PKC activation. This study, therefore, identifies aldosterone as an active member of the RAAS for the regulation of luminal acidification in the proximal epididymis.

  2. Aldosterone hypersecretion in “non-salt-losing” congenital adrenal hyperplasia

    PubMed Central

    Bartter, Frederic C.; Henkin, Robert I.; Bryan, George T.

    1968-01-01

    Patients with the “non-salt-losing” form of the adrenogenital syndrome were studied before and after suppression of adrenal cortical activity with carbohydrate-active steroids. The response of aldosterone secretion to sodium deprivation was measured; in some patients response to adrenocorticotropic hormone (ACTH) was measured as well. The aldosterone secretion was normal and responded normally to sodium deprivation in all patients studied during suppression with carbohydrate-active steroids. This finding suggests that 21-hydroxylation of progesterone is normal in this syndrome. The sole abnormality in the production of aldosterone in these patients was found to be excessive secretion of aldosterone while they were not receiving suppressive doses of carbohydrate-active steroids. This finding strongly supports the view that the biogenetic pathways through which aldosterone is produced from progesterone are intact in this syndrome. No patient showed hypertension or hypokalemic alkalosis despite very high aldosterone secretion rates. This observation suggests that the hyper-aldosteronism is secondary to a tendency to sodium loss in the patient whose ACTH production is not suppressed. These studies provide additional evidence in support of the hypothesis that the salt-losing and “non-salt-losing” forms of adrenogenital syndrome are genetically and biochemically distinct. PMID:4299011

  3. Aldosterone, cognitive function, and cerebral hemodynamics in hypertension and antihypertensive therapy.

    PubMed

    Hajjar, Ihab; Hart, Meaghan; Mack, Wendy; Lipsitz, Lewis A

    2015-03-01

    Animal studies suggest that the renin-angiotensin-aldosterone system is involved in neurocognitive function and the response to antihypertensive therapy. We investigated the impact of circulating aldosterone and renin activity on cognition and cerebral hemodynamics at baseline and after antihypertensive therapy for 1 year. Participants were older adults (n = 47; mean age = 71 years) enrolled in a clinical trial. Routine antihypertensive medications were replaced with the study regimen to achieve a blood pressure <140/90 mm Hg. Executive function, memory, cerebral hemodynamics (blood flow velocity), CO2 vasoreactivity (measured using transcranial Doppler ultrasonography), plasma renin activity, and aldosterone were measured at baseline and at 6 and 12 months after the initiation of treatment. At baseline, higher levels of circulating aldosterone were associated with lower blood flow velocity (β = -0.02; P = 0.03), lower CO2 vasoreactivity (β = -0.11; P = 0.007), and decreased autoregulation abilities (β = -0.09; P = 0.01). Those with higher levels of aldosterone at baseline demonstrated the greatest improvement in executive function (P = 0.014 for the aldosterone effect) and in CO2 vasoreactivity (P = 0.026 for the aldosterone effect) after 12 months of lowering blood pressure (<140/90 mm Hg). Plasma renin activity was not associated with any of the measures. Higher levels of aldosterone may be associated with decreased cerebrovascular function in hypertension. Those with higher aldosterone levels may benefit the most from lowering blood pressure. The role of aldosterone in brain health warrants further investigation in a larger trial. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Analysis of postoperative biochemical values and clinical outcomes after adrenalectomy for primary aldosteronism.

    PubMed

    Swearingen, Andrew J; Kahramangil, Bora; Monteiro, Rosebel; Krishnamurthy, Vikram; Jin, Judy; Shin, Joyce; Siperstein, Allan; Berber, Eren

    2018-04-01

    Primary aldosteronism causes hypertension and hypokalemia and is often surgically treatable. Diagnosis includes elevated plasma aldosterone, suppressed plasma renin activity, and elevated aldosterone renin ratio. Adrenalectomy improves hypertension and hypokalemia. Postoperative plasma aldosterone and plasma renin activity may be useful in documenting cure or failure. A retrospective analysis of patients who underwent adrenalectomy for primary aldosteronism from 2010 to 2016 was performed, analyzing preoperative and postoperative plasma aldosterone, plasma renin activity, hypertension, and hypokalemia. The utility of postoperative testing was assessed. Clinical cure was defined as improved hypertension control and resolution of potassium loss. Biochemical cure was defined as aldosterone renin ratio reduction to <23.6. Forty-four patients were included; 20 had plasma aldosterone and plasma renin activity checked on postoperative day 1. In the study, 40/44 (91%) were clinically cured. All clinical failures had of biochemical failure at follow-up. Postoperative day 1aldosterone renin ratio <23.6 had PPV of 95% for clinical cure. Cured patients had mean plasma aldosterone drop of 33.1 ng/dL on postoperative day 1; noncured patient experienced 3.9 ng/dL increase. A cutoff of plasma aldosterone decrease of 10 ng/dL had high positive predictive value for clinical cure. Changes in plasma aldosterone and plasma renin activity after adrenalectomy correlate with improved hypertension and hypokalemia. The biochemical impact of adrenalectomy manifests as early as postoperative day 1. We propose a plasma aldosterone decrease of 10 ng/dL as a criterion to predict clinical cure. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Macrolides for KCNJ5-mutated aldosterone-producing adenoma (MAPA): design of a study for personalized diagnosis of primary aldosteronism.

    PubMed

    Maiolino, Giuseppe; Ceolotto, Giulio; Battistel, Michele; Barbiero, Giulio; Cesari, Maurizio; Amar, Laurence; Caroccia, Brasilina; Padrini, Roberto; Azizi, Michel; Rossi, Gian Paolo

    2018-02-06

    Aldosterone-producing adenoma (APA) is the main curable cause of endocrine hypertension cause of primary aldosteronism (PA) and it is in up to 66% of all cases investigated with adrenal vein sampling (AVS). Mutations in the KCNJ5 potassium channel involve up to 70% of APA and cause the most florid PA phenotypes. The recent finding that macrolide antibiotics specifically inhibit in vitro the altered function of mutated KCNJ5 channels has opened new horizons for the diagnosis and treatment of APA with KCNJ5 mutations in that it can allow identification and target treatment of PA patients harbouring a mutated APA. Thus, we aimed at investigating if clarithromycin and roxithromycin, two macrolides that potently blunt mutated Kir3.4 channel function in vitro, affect plasma aldosterone concentration in adrenal vein blood during AVS and in peripheral blood, respectively, in PA patients with a mutated APA. We designed two proof of concept studies. In study A: consecutive patients with an unambiguous biochemical evidence of PA will be exposed to a single dose of 250 mg clarithromycin during AVS, to assess its effect on the relative aldosterone secretion index in adrenal vein blood from the gland with and without APA. In study B: consecutive hypertensive patients submitted to the work-up for hypertension will receive a single oral dose of 150 mg roxithromycin. The experimental endpoints will be the change induced by roxithromycin of plasma aldosterone concentration and other steroids, direct active renin concentration, serum K + , systolic and diastolic blood pressure. We expect to prove that: (i) clarithromycin allows identification of mutated APA before adrenalectomy and sequencing of tumour DNA; (ii) the acute changes of plasma aldosterone concentration, direct active renin concentration, and blood pressure in peripheral venous blood after roxithromycin can be a proxy for the presence of an APA with somatic mutations.

  6. The Spectrum of Subclinical Primary Aldosteronism and Incident Hypertension: A Cohort Study

    PubMed Central

    Brown, Jenifer M.; Robinson-Cohen, Cassianne; Fernandez, Miguel Angel Luque; Allison, Matthew A.; Baudrand, Rene; Ix, Joachim H.; Kestenbaum, Bryan; de Boer, Ian H.; Vaidya, Anand

    2018-01-01

    Background Primary aldosteronism is recognized as a severe form of “renin-independent aldosteronism” that results in excessive mineralocorticoid receptor (MR) activation. Objective To investigate whether there is a spectrum of subclinical renin-independent aldosteronism among normotensives that increases risk for hypertension. Design Cohort study. Setting National community-based study. Participants 850 untreated normotensive participants in the Multi-Ethnic Study of Atherosclerosis with measurements of serum aldosterone, plasma renin activity (PRA). Measurements Longitudinal analyses investigated whether aldosterone concentrations, in the context of physiologic PRA phenotypes (suppressed: ≤0.50; indeterminate: 0.51–0.99; unsuppressed: ≥1.0 μg/L/h), associated with incident hypertension, defined as SBP≥140, DBP≥90 mmHg, or initiation of anti-hypertensive medications. Cross-sectional analyses investigated associations of aldosterone with MR activity, assessed via serum potassium and urinary fractional excretion of potassium. Results A suppressed renin phenotype was associated with a higher rate of incident hypertension when compared to other PRA phenotypes (85.4 [73.4, 99.3] vs. 53.3 [42.8, 66.4] vs. 54.5 [41.8, 71.0] cases per 1000 person-years of follow-up). With renin suppression, higher aldosterone concentrations were independently associated with an increased risk for incident hypertension; whereas no association between aldosterone and hypertension was observed when renin was not suppressed. Higher aldosterone concentrations were associated with lower serum potassium and higher urinary excretion of potassium, but only when renin was suppressed. Limitations Measurements of sodium and potassium occurred several years before renin and aldosterone. Conclusions Suppression of renin, and higher aldosterone concentrations in the context of this renin suppression, associated with an increased risk for developing hypertension and possibly also with

  7. The role of prostacyclin synthase and thromboxane synthase signaling in the development and progression of cancer.

    PubMed

    Cathcart, Mary-Clare; Reynolds, John V; O'Byrne, Kenneth J; Pidgeon, Graham P

    2010-04-01

    Prostacyclin synthase and thromboxane synthase signaling via arachidonic acid metabolism affects a number of tumor cell survival pathways such as cell proliferation, apoptosis, tumor cell invasion and metastasis, and angiogenesis. However, the effects of these respective synthases differ considerably with respect to the pathways described. While prostacyclin synthase is generally believed to be anti-tumor, a pro-carcinogenic role for thromboxane synthase has been demonstrated in a variety of cancers. The balance of oppositely-acting COX-derived prostanoids influences many processes throughout the body, such as blood pressure regulation, clotting, and inflammation. The PGI(2)/TXA(2) ratio is of particular interest in-vivo, with the corresponding synthases shown to be differentially regulated in a variety of disease states. Pharmacological inhibition of thromboxane synthase has been shown to significantly inhibit tumor cell growth, invasion, metastasis and angiogenesis in a range of experimental models. In direct contrast, prostacyclin synthase overexpression has been shown to be chemopreventive in a murine model of the disease, suggesting that the expression and activity of this enzyme may protect against tumor development. In this review, we discuss the aberrant expression and known functions of both prostacyclin synthase and thromboxane synthase in cancer. We discuss the effects of these enzymes on a range of tumor cell survival pathways, such as tumor cell proliferation, induction of apoptosis, invasion and metastasis, and tumor cell angiogenesis. As downstream signaling pathways of these enzymes have also been implicated in cancer states, we examine the role of downstream effectors of PGIS and TXS activity in tumor growth and progression. Finally, we discuss current therapeutic strategies aimed at targeting these enzymes for the prevention/treatment of cancer.

  8. Hypertension: renin-angiotensin-aldosterone system alterations.

    PubMed

    Te Riet, Luuk; van Esch, Joep H M; Roks, Anton J M; van den Meiracker, Anton H; Danser, A H Jan

    2015-03-13

    Blockers of the renin-angiotensin-aldosterone system (RAAS), that is, renin inhibitors, angiotensin (Ang)-converting enzyme (ACE) inhibitors, Ang II type 1 receptor antagonists, and mineralocorticoid receptor antagonists, are a cornerstone in the treatment of hypertension. How exactly they exert their effect, in particular in patients with low circulating RAAS activity, also taking into consideration the so-called Ang II/aldosterone escape that often occurs after initial blockade, is still incompletely understood. Multiple studies have tried to find parameters that predict the response to RAAS blockade, allowing a personalized treatment approach. Consequently, the question should now be answered on what basis (eg, sex, ethnicity, age, salt intake, baseline renin, ACE or aldosterone, and genetic variance) a RAAS blocker can be chosen to treat an individual patient. Are all blockers equal? Does optimal blockade imply maximum RAAS blockade, for example, by combining ≥2 RAAS blockers or by simply increasing the dose of 1 blocker? Exciting recent investigations reveal a range of unanticipated extrarenal effects of aldosterone, as well as a detailed insight in the genetic causes of primary aldosteronism, and mineralocorticoid receptor blockers have now become an important treatment option for resistant hypertension. Finally, apart from the deleterious ACE-Ang II-Ang II type 1 receptor arm, animal studies support the existence of protective aminopeptidase A-Ang III-Ang II type 2 receptor and ACE2-Ang-(1 to 7)-Mas receptor arms, paving the way for multiple new treatment options. This review provides an update about all these aspects, critically discussing the many controversies and allowing the reader to obtain a full understanding of what we currently know about RAAS alterations in hypertension. © 2015 American Heart Association, Inc.

  9. Cloning, expression, crystallization and preliminary X-ray data analysis of norcoclaurine synthase from Thalictrum flavum

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Pasquo, Alessandra; Bonamore, Alessandra; Franceschini, Stefano

    The cloning, expression, crystallization and preliminary X-ray data analysis of norcoclaurine synthase from T. flavum, a protein which catalyzes the first committed step in the biosynthesis of benzylisoquinoline alkaloids, are reported. Norcoclaurine synthase (NCS) catalyzes the condensation of 3,4-dihydroxyphenylethylamine (dopamine) and 4-hydroxyphenylacetaldehyde (4-HPAA) as the first committed step in the biosynthesis of benzylisoquinoline alkaloids in plants. The protein was cloned, expressed and purified. Crystals were obtained at 294 K by the hanging-drop vapour-diffusion method using ammonium sulfate and sodium chloride as precipitant agents and diffract to better than 3.0 Å resolution using a synchrotron-radiation source. The crystals belong to themore » trigonal space group P3{sub 1}21, with unit-cell parameters a = b = 86.31, c = 118.36 Å. A selenomethionine derivative was overexpressed, purified and crystallized in the same space group. A complete MAD data set was collected at 2.7 Å resolution. The model is under construction.« less

  10. Ovariectomy modify local renin-angiotensin-aldosterone system gene expressions in the heart of ApoE (-/-) mice.

    PubMed

    Borges, Celina Carvalho; Penna-de-Carvalho, Aline; Medeiros Junior, Jorge L; Aguila, Marcia Barbosa; Mandarim-de-Lacerda, Carlos A

    2017-12-15

    The evaluation of the local Renin-Angiotensin-Aldosterone system (RAAS) gene expressions in the heart of ovariectomized (OVX) apolipoprotein E deficient mice (ApoE). Four-months old C57BL/6 female mice (wild-type, wt, n=20), and ApoE female mice (n=20), were submitted to OVX or a surgical procedure without ovary removal (SHAM) and formed four groups (n=10/group): SHAM/wt, SHAM/ApoE, OVX/wt, and OVX/ApoE. OVX led to greater body mass, plasma triglycerides (TG) and total cholesterol, and resulted in insulin resistance and altered RAAS gene expressions in the heart tissue. The gene expression of angiotensin-converting enzyme (ACE)-2 was lower in OVX/wt than in SHAM/wt (P=0.0004), Mas receptor (MASr) was lower in OVX/wt compared to SHAM/wt (P<0.0001). Also, angiotensin II receptor type 1 (AT1r) was higher in OVX/wt than in SHAM/wt (P=0.0229), and AT2r was lower in OVX/wt than in SHAM/wt (P=0.0121). OVX and ApoE deficiency showed interaction potentializing the insulin resistance, increasing TG levels and altering ACE and MASr gene expressions. ACE gene expression was higher in OVX/ApoE than in OVX/wt (P<0.0001), and MASr gene expression was lower in OVX/ApoE than in OVX/wt (P<0.0001). The impact of OVX on local RAAS cascade in the heart of ApoE deficient animals, besides the metabolic changes culminating with insulin resistance, involves an upregulation of renin, ACE, and AT1r gene expressions. The findings may contribute to clarify the mechanisms of development of postmenopausal hypertension and the link between RAAS and apolipoprotein E. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. VLDL-activated cell signaling pathways that stimulate adrenal cell aldosterone production

    PubMed Central

    Tsai, Ying-Ying; Rainey, William E.; Johnson, Maribeth H.; Bollag, Wendy B.

    2016-01-01

    Aldosterone plays an important role in regulating ion and fluid homeostasis and thus blood pressure, and hyperaldosteronism results in hypertension. Hypertension is also observed with obesity, which is associated with additional health risks, including cardiovascular disease. Obese individuals have high serum levels of very low-density lipoprotein (VLDL), which has been shown to stimulate aldosterone production; however, the mechanisms underlying VLDL-induced aldosterone production are still unclear. Here we demonstrate in human adrenocortical carcinoma (HAC15) cells that submaximal concentrations of angiotensin II and VLDL stimulate aldosterone production in an additive fashion, suggesting the possibility of common mechanisms of action. We show using inhibitors that VLDL-induced aldosterone production is mediated by the PLC/IP3/PKC signaling pathway. Our results suggest that PKC is upstream of the extracellular signal-regulated kinase (ERK) activation previously observed with VLDL. An understanding of the mechanisms mediating VLDL-induced aldosterone production may provide insights into therapies to treat obesity-associated hypertension. PMID:27222295

  12. VLDL-activated cell signaling pathways that stimulate adrenal cell aldosterone production.

    PubMed

    Tsai, Ying-Ying; Rainey, William E; Johnson, Maribeth H; Bollag, Wendy B

    2016-09-15

    Aldosterone plays an important role in regulating ion and fluid homeostasis and thus blood pressure, and hyperaldosteronism results in hypertension. Hypertension is also observed with obesity, which is associated with additional health risks, including cardiovascular disease. Obese individuals have high serum levels of very low-density lipoprotein (VLDL), which has been shown to stimulate aldosterone production; however, the mechanisms underlying VLDL-induced aldosterone production are still unclear. Here we demonstrate in human adrenocortical carcinoma (HAC15) cells that submaximal concentrations of angiotensin II and VLDL stimulate aldosterone production in an additive fashion, suggesting the possibility of common mechanisms of action. We show using inhibitors that VLDL-induced aldosterone production is mediated by the PLC/IP3/PKC signaling pathway. Our results suggest that PKC is upstream of the extracellular signal-regulated kinase (ERK) activation previously observed with VLDL. An understanding of the mechanisms mediating VLDL-induced aldosterone production may provide insights into therapies to treat obesity-associated hypertension. Published by Elsevier Ireland Ltd.

  13. Mechanisms of connecting tubule glomerular feedback enhancement by aldosterone

    PubMed Central

    Ren, YiLin; Janic, Branislava; Kutskill, Kristopher; Peterson, Edward L.

    2016-01-01

    Connecting tubule glomerular feedback (CTGF) is a mechanism where an increase in sodium (Na) concentration in the connecting tubule (CNT) causes the afferent arteriole (Af-Art) to dilate. We recently reported that aldosterone within the CNT lumen enhances CTGF via a nongenomic effect involving GPR30 receptors and sodium/hydrogen exchanger (NHE), but the signaling pathways of this mechanism are unknown. We hypothesize that aldosterone enhances CTGF via cAMP/protein kinase A (PKA) pathway that activates protein kinase C (PKC) and stimulates superoxide (O2−) production. Rabbit Af-Arts and their adherent CNTs were microdissected and simultaneously perfused. Two consecutive CTGF curves were elicited by increasing the CNT luminal NaCl. We found that the main effect of aldosterone was to sensitize CTGF and we analyzed data by comparing NaCl concentration in the CNT perfusate needed to achieve half of the maximal response (EC50). During the control period, the NaCl concentration that elicited a half-maximal response (EC50) was 37.0 ± 2.0 mmol/l; addition of aldosterone (10−8 mol/l) to the CNT lumen decreased EC50 to 19.3 ± 1.3 mmol/l (P ≤ 0.001 vs. Control). The specific adenylyl cyclase inhibitor 2′,3′-dideoxyadenosine (ddA; 2 × 10−4 mol/l) and the PKA inhibitor H-89 dihydrochloride hydrate (H-89; 2 × 10−6 mol/l) prevented the aldosterone effect. The selective PKC inhibitor GF109203X (10−8 mol/l) also prevented EC50 reduction caused by aldosterone. CNT intraluminal addition of O2− scavenger tempol (10−4 mol/l) blocked the aldosterone effect. We conclude that aldosterone inside the CNT lumen enhances CTGF via a cAMP/PKA/PKC pathway and stimulates O2− generation and this process may contribute to renal damage by increasing glomerular capillary pressure. PMID:27413197

  14. Aldosterone and parathyroid hormone interactions as mediators of metabolic and cardiovascular disease.

    PubMed

    Tomaschitz, Andreas; Ritz, Eberhard; Pieske, Burkert; Rus-Machan, Jutta; Kienreich, Katharina; Verheyen, Nicolas; Gaksch, Martin; Grübler, Martin; Fahrleitner-Pammer, Astrid; Mrak, Peter; Toplak, Hermann; Kraigher-Krainer, Elisabeth; März, Winfried; Pilz, Stefan

    2014-01-01

    Inappropriate aldosterone and parathyroid hormone (PTH) secretion is strongly linked with development and progression of cardiovascular (CV) disease. Accumulating evidence suggests a bidirectional interplay between parathyroid hormone and aldosterone. This interaction may lead to a disproportionally increased risk of CV damage, metabolic and bone diseases. This review focuses on mechanisms underlying the mutual interplay between aldosterone and PTH as well as their potential impact on CV, metabolic and bone health. PTH stimulates aldosterone secretion by increasing the calcium concentration in the cells of the adrenal zona glomerulosa as a result of binding to the PTH/PTH-rP receptor and indirectly by potentiating angiotensin 2 induced effects. This may explain why after parathyroidectomy lower aldosterone levels are seen in parallel with improved cardiovascular outcomes. Aldosterone mediated effects are inappropriately pronounced in conditions such as chronic heart failure, excess dietary salt intake (relative aldosterone excess) and primary aldosteronism. PTH is increased as a result of (1) the MR (mineralocorticoid receptor) mediated calciuretic and magnesiuretic effects with a trend of hypocalcemia and hypomagnesemia; the resulting secondary hyperparathyroidism causes myocardial fibrosis and disturbed bone metabolism; and (2) direct effects of aldosterone on parathyroid cells via binding to the MR. This adverse sequence is interrupted by mineralocorticoid receptor blockade and adrenalectomy. Hyperaldosteronism due to klotho deficiency results in vascular calcification, which can be mitigated by spironolactone treatment. In view of the documented reciprocal interaction between aldosterone and PTH as well as the potentially ensuing target organ damage, studies are needed to evaluate diagnostic and therapeutic strategies to address this increasingly recognized pathophysiological phenomenon. © 2013.

  15. Aldosterone dysregulation with aging predicts renal vascular function and cardiovascular risk.

    PubMed

    Brown, Jenifer M; Underwood, Patricia C; Ferri, Claudio; Hopkins, Paul N; Williams, Gordon H; Adler, Gail K; Vaidya, Anand

    2014-06-01

    Aging and abnormal aldosterone regulation are both associated with vascular disease. We hypothesized that aldosterone dysregulation influences the age-related risk of renal vascular and cardiovascular disease. We conducted an analysis of 562 subjects who underwent detailed investigations under conditions of liberal and restricted dietary sodium intake (1124 visits) in the General Clinical Research Center. Aldosterone regulation was characterized by the ratio of maximal suppression to stimulation (supine serum aldosterone on a liberal sodium diet divided by the same measure on a restricted sodium diet). We previously demonstrated that higher levels of this Sodium-modulated Aldosterone Suppression-Stimulation Index (SASSI) indicate greater aldosterone dysregulation. Renal plasma flow (RPF) was determined via p-aminohippurate clearance to assess basal renal hemodynamics and the renal vascular responses to dietary sodium manipulation and angiotensin II infusion. Cardiovascular risk was calculated using the Framingham Risk Score. In univariate linear regression, older age (β=-4.60; P<0.0001) and higher SASSI (β=-58.63; P=0.001) predicted lower RPF and a blunted RPF response to sodium loading and angiotensin II infusion. We observed a continuous, independent, multivariate-adjusted interaction between age and SASSI, where the inverse relationship between SASSI and RPF was most apparent with older age (P<0.05). Higher SASSI and lower RPF independently predicted higher Framingham Risk Score (P<0.0001) and together displayed an additive effect. Aldosterone regulation and age may interact to mediate renal vascular disease. Our findings suggest that the combination of aldosterone dysregulation and renal vascular dysfunction could additively increase the risk of future cardiovascular outcomes; therefore, aldosterone dysregulation may represent a modifiable mechanism of age-related vascular disease.

  16. Aldosterone-Signaling Defect Exacerbates Sodium Wasting in Very Preterm Neonates: The Premaldo Study.

    PubMed

    Martinerie, Laetitia; Pussard, Eric; Yousef, Nadya; Cosson, Claudine; Lema, Ingrid; Husseini, Khaled; Mur, Sébastien; Lombès, Marc; Boileau, Pascal

    2015-11-01

    The neonatal period, notably in preterm infants, is characterized by high sodium wasting, implying that aldosterone, the main hormone regulating sodium reabsorption, is unable to maintain sodium homeostasis. This study sought to assess aldosterone secretion and action in neonates according to gestational age (GA). This was a multicenter prospective study (NCT01176162) conducted between 2011 and 2014 at five neonatology departments in France. Infants were followed during their first 3 months. The 155 newborns included were classified into three groups: Group 1 (n = 46 patients), <33 gestational weeks (GW); Group 2 (n = 67 patients), 33-36 GW; and Group 3 (n = 42 patients), ≥37 GW. Plasma aldosterone was measured in umbilical cord blood. Urinary aldosterone (UAldo) was assessed at day 0, day 3, month 1, and month 3 postnatal. The correlation between UAldo and the urinary Na/K ratio was determined as an index of renal aldosterone sensitivity. UAldo significantly increased with GA: from 8.8 ± 7.5 μg/mmol of creatinine (Group 1) to 21.1 ± 21.0 (Group 3) in correlation with plasma aldosterone levels in all groups (P < .001), demonstrating its reliability. The aldosterone/renin ratio significantly increased with GA, suggesting an aldosterone secretion defect in preterm infants. UAldo and urinary Na/K were correlated in very preterm but not in term neonates, consistent with very preterm neonates being renal-aldosterone sensitive and term neonates being aldosterone resistant. Very preterm infants have a previously unrecognized defective aldosterone secretion but conserved renal aldosterone sensitivity in the neonatal period, which modifies the current view of sodium balance in these infants and suggests alternative management approaches.

  17. Aldosterone-to-Renin Ratio Is Associated With Reduced 24-Hour Heart Rate Variability and QTc Prolongation in Hypertensive Patients

    PubMed Central

    Grübler, Martin R.; Kienreich, Katharina; Gaksch, Martin; Verheyen, Nicolas; Hartaigh, Bríain Ó.; Fahrleitner-Pammer, Astrid; März, Winfried; Schmid, Johannes; Oberreither, Eva-Maria; Wetzel, Julia; Catena, Cristiana; Sechi, Leonardo A.; Pieske, Burkert; Tomaschitz, Andreas; Pilz, Stefan

    2016-01-01

    Abstract Aldosterone is considered to exert direct effects on the myocardium and the sympathetic nervous system. Both QT time and heart rate (HR) variability (HRV) are considered to be markers of arrhythmic risk and autonomous dysregulation. In this study, we investigated the associations between aldosterone, QT time, and HRV in patients with arterial hypertension. We recruited 477 hypertensive patients (age: 60.2 ± 10.2 years; 52.3% females) with a mean systolic/diastolic 24-hour ambulatory blood pressure monitoring (ABPM) value of 128 ± 12.8/77.1 ± 9.2 mmHg and with a median of 2 (IQR: 1–3) antihypertensive agents. Patients were recruited from the outpatient clinic at the Department of Internal Medicine of the Medical University of Graz, Austria. Blood samples, 24-hour HRV derived from 24-hour blood pressure monitoring (ABPM) and ECG's were obtained. Plasma aldosterone and plasma renin concentrations were measured by means of a radioimmunoassay. Twenty-four-hour urine specimens were collected in parallel with ABPM. Mean QTc was 423.3 ± 42.0 milliseconds for males and 434.7 ± 38.3 milliseconds for females. Mean 24H-HR and 24H-HRV was 71.9 ± 9.8 and 10.0 ± 3.6 bpm, respectively. In linear regression analyses adjusted for age, sex, body mass index, ABPM, and current medication, aldosterone to active renin ratio (AARR) was significantly associated with the QTc interval, a marker for cardiac repolarization abnormalities (mean = 426 ± 42.4 milliseconds; β-coefficient = 0.121; P = 0.03) as well as with the 24-hour heart rate variability a surrogate for autonomic dysfunction (median = 9.67 [IQR = 7.38–12.22 bpm]; β-coefficient = −0.133; P = 0.01). In hypertensive patients, AARR is significantly related to QTc prolongation as well as HRV. Further studies investigating the effects of mineralocorticoid receptor blocker and aldosterone synthase inhibitors on QTc and HRV are warranted

  18. Cloning and heterologous expression of chlorophyll a synthase in Rhodobacter sphaeroides.

    PubMed

    Ipekoğlu, Emre M; Göçmen, Koray; Öz, Mehmet T; Gürgan, Muazzez; Yücel, Meral

    2017-03-01

    Rhodobacter sphaeroides is a purple non-sulfur bacterium which photoheterotrophically produces hydrogen from organic acids under anaerobic conditions. A gene coding for putative chlorophyll a synthase (chlG) from cyanobacterium Prochlorococcus marinus was amplified by nested polymerase chain reaction and cloned into an inducible-expression plasmid which was subsequently transferred to R. sphaeroides for heterologous expression. Induced expression of chlG in R. sphaeroides led to changes in light absorption spectrum within 400-700 nm. The hydrogen production capacity of the mutant strain was evaluated on hydrogen production medium with 15 mM malate and 2 mM glutamate. Hydrogen yield and productivity were increased by 13.6 and 22.6%, respectively, compared to the wild type strain. The results demonstrated the feasibility of genetic engineering to combine chlorophyll and bacteriochlorophyll biosynthetic pathways which utilize common intermediates. Heterologous expression of key enzymes from biosynthetic pathways of various pigments is proposed here as a general strategy to improve absorption spectra and yield of photosynthesis and hydrogen gas production in bacteria. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Inhibition of inducible nitric oxide synthase expression by novel nonsteroidal anti-inflammatory derivatives with gastrointestinal-sparing properties.

    PubMed Central

    Cirino, G.; Wheeler-Jones, C. P.; Wallace, J. L.; Del Soldato, P.; Baydoun, A. R.

    1996-01-01

    1. The effects of novel nitric oxide-releasing nonsteroidal anti-inflammatory compounds (NO-NSAIDs) on induction of nitric oxide (NO) synthase by bacterial lipopolysaccharide (LPS) were examined in a murine cultured macrophage cell line, J774. 2. LPS-induced nitrite production was markedly attenuated by the nitroxybutylester derivatives of flurbiprofen (FNBE), aspirin, ketoprofen, naproxen, diclofenac and ketorolac, with each compound reducing accumulated nitrite levels by > 40% at the maximum concentrations (100 micrograms ml-1) used. 3. Further examination revealed that nitrite production was inhibited in a concentration-dependent (1-100 micrograms ml-1) manner by FNBE which at 100 micrograms ml-1 decreased LPS-stimulated levels by 63.3 +/- 8.6% (n = 7). The parent compound flurbiprofen was relatively ineffective over the same concentration-range, inhibiting nitrite accumulation by 24 +/- 0.9% (n = 3) at the maximum concentration used (100 micrograms ml-1). 4. FNBE reduced LPS-induced nitrite production when added to cells up to 4 h after LPS. Thereafter, FNBE caused very little or no reduction in nitrite levels. Furthermore NO-NSAIDs (100 micrograms ml-1) did not inhibit the metabolism of L-[3H]-arginine to citrulline by NO synthase isolated from LPS-activated macrophages. 5. Western blot analysis demonstrated that NO synthase expression was markedly attenuated following co-incubation of J774 cell with LPS (1 microgram ml-1; 24 h) and FNBE (100 micrograms ml-1; 24 h). Thus taken together, these findings indicate that NO-NSAIDs inhibit induction of NO synthase without directly affecting enzyme activity. 6. In conclusion our results indicate that NO-NSAIDs can inhibit the inducible L-arginine-NO pathway, and are capable of suppressing NO synthesis by inhibiting expression of NO synthase. The clinical implications of these findings remain to be established. Images Figure 4 PMID:8730734

  20. The Role of Aldosterone in Obesity-Related Hypertension

    PubMed Central

    Kawarazaki, Wakako

    2016-01-01

    Obese subjects often have hypertension and related cardiovascular and renal diseases, and this has become a serious worldwide health problem. In obese subjects, impaired renal-pressure natriuresis causes sodium retention, leading to the development of salt-sensitive hypertension. Physical compression of the kidneys by visceral fat and activation of the sympathetic nervous system, renin–angiotensin systems (RAS), and aldosterone/mineralocorticoid receptor (MR) system are involved in this mechanism. Obese subjects often exhibit hyperaldosteronism, with increased salt sensitivity of blood pressure (BP). Adipose tissue excretes aldosterone-releasing factors, thereby stimulating aldosterone secretion independently of the systemic RAS, and aldosterone/MR activation plays a key role in the development of hypertension and organ damage in obesity. In obese subjects, both salt sensitivity of BP, enhanced by obesity-related metabolic disorders including aldosterone excess, and increased dietary sodium intake are closely related to the incidence of hypertension. Some salt sensitivity-related gene variants affect the risk of obesity, and together with salt intake, its combination is possibly associated with the development of hypertension in obese subjects. With high salt levels common in modern diets, salt restriction and weight control are undoubtedly important. However, not only MR blockade but also new diagnostic modalities and therapies targeting and modifying genes that are related to salt sensitivity, obesity, or RAS regulation are expected to prevent obesity and obesity-related hypertension. PMID:26927805

  1. GENETICS IN ENDOCRINOLOGY: The expanding genetic horizon of primary aldosteronism.

    PubMed

    Monticone, Silvia; Buffolo, Fabrizio; Tetti, Martina; Veglio, Franco; Pasini, Barbara; Mulatero, Paolo

    2018-03-01

    Aldosterone is the main mineralocorticoid hormone in humans and plays a key role in maintaining water and electrolyte homeostasis. Primary aldosteronism (PA), characterized by autonomous aldosterone overproduction by the adrenal glands, affects 6% of the general hypertensive population and can be either sporadic or familial. Aldosterone-producing adenoma (APA) and bilateral adrenal hyperplasia (BAH) are the two most frequent subtypes of sporadic PA and 4 forms of familial hyperaldosteronism (FH-I to FH-IV) have been identified. Over the last six years, the introduction of next-generation sequencing has significantly improved our understanding of the molecular mechanisms responsible for autonomous aldosterone overproduction in both sporadic and familial PA. Somatic mutations in four genes ( KCNJ5, ATP1A1, ATP2B3 and CACNA1D ), differently implicated in intracellular ion homeostasis, have been identified in nearly 60% of the sporadic APAs. Germline mutations in KCNJ5 and CACNA1H cause FH-III and FH-IV, respectively, while germline mutations in CACNA1D cause the rare PASNA syndrome, featuring primary aldosteronism seizures and neurological abnormalities. Further studies are warranted to identify the molecular mechanisms underlying BAH and FH-II, the most common forms of sporadic and familial PA whose molecular basis is yet to be uncovered. © 2018 European Society of Endocrinology.

  2. GPR48 Increases Mineralocorticoid Receptor Gene Expression

    PubMed Central

    Wang, Jiqiu; Li, Xiaoying; Ke, Yingying; Lu, Yan; Wang, Feng; Fan, Nengguang; Sun, Haiyan; Zhang, Huijie; Liu, Ruixin; Yang, Jun; Ye, Lei; Liu, Mingyao

    2012-01-01

    Aldosterone and the mineralocorticoid receptor (MR) are critical to the maintenance of electrolyte and BP homeostasis. Mutations in the MR cause aldosterone resistance known as pseudohypoaldosteronism type 1 (PHA1); however, some cases consistent with PHA1 do not exhibit known gene mutations, suggesting the possibility of alternative genetic variants. We observed that G protein–coupled receptor 48 (Gpr48/Lgr4) hypomorphic mutant (Gpr48m/m) mice had hyperkalemia and increased water loss and salt excretion despite elevated plasma aldosterone levels, suggesting aldosterone resistance. When we challenged the mice with a low-sodium diet, these features became more obvious; the mice also developed hyponatremia and increased renin expression and activity, resembling a mild state of PHA1. There was marked renal downregulation of MR and its downstream targets (e.g., the α-subunit of the amiloride-sensitive epithelial sodium channel), which could provide a mechanism for the aldosterone resistance. We identified a noncanonical cAMP-responsive element located in the MR promoter and demonstrated that GPR48 upregulates MR expression via the cAMP/protein kinase A pathway in vitro. Taken together, our data demonstrate that GPR48 enhances aldosterone responsiveness by activating MR expression, suggesting that GPR48 contributes to homeostasis of electrolytes and BP and may be a candidate gene for PHA1. PMID:22135314

  3. PCP4: a regulator of aldosterone synthesis in human adrenocortical tissues

    PubMed Central

    Felizola, Saulo J. A.; Nakamura, Yasuhiro; Ono, Yoshikiyo; Kitamura, Kanako; Kikuchi, Kumi; Onodera, Yoshiaki; Ise, Kazue; Takase, Kei; Sugawara, Akira; Hattangady, Namita; Rainey, William E.; Satoh, Fumitoshi; Sasano, Hironobu

    2014-01-01

    Purkinje cell protein 4 (PCP4) is a calmodulin (CaM) binding protein that accelerates calcium association and dissociation with CaM. It has been previously detected in aldosterone-producing adenomas (APA) but details on its expression and function in adrenocortical tissues have remained unknown. Therefore, we performed the immunohistochemical analysis of PCP4 in the following tissues: normal adrenal (NA; n=15), APA (n=15), cortisol producing adenomas (CPA; n=15) and idiopathic hyperaldosteronism cases (IHA; n=5). APA samples (n=45) were also submitted to quantitative RT-PCR (qPCR) of PCP4, CYP11B1, and CYP11B2, as well as DNA sequencing for KCNJ5 mutations. Transient transfection analysis using PCP4 siRNA was also performed in H295R adrenocortical carcinoma cells, following ELISA analysis, and CYP11B2 luciferase assays were also performed after PCP4 vector transfection in order to study the regulation of PCP4 protein expression. In our findings, PCP4 immunoreactivity was predominantly detected in APA and in the zona glomerulosa (ZG) of NA and IHA. In APA, the mRNA levels of PCP4 were significantly correlated with those of CYP11B2 (P<0.0001) and were significantly higher in cases with KCNJ5 mutation than wild-type (P=0.005). Following PCP4 vector transfection, CYP11B2 luciferase reporter activity was significantly higher than controls in the presence of angiotensin-II. Knockdown of PCP4 resulted in a significant decrease in CYP11B2 mRNA levels (P=0.012) and aldosterone production (P=0.011). Our results indicate that PCP4 is a regulator of aldosterone production in normal, hyperplastic and neoplastic human adrenocortical cells. PMID:24403568

  4. Measurement of salivary aldosterone: validation by low-dose ACTH test and gender differences.

    PubMed

    Hlavacova, N; Kerlik, J; Radikova, Z; Izakova, L; Jezova, D

    2013-10-01

    The aim of the present study was to validate the feasibility of measurement of the salivary aldosterone concentrations by performing a low-dose adrenocorticotropic hormone (ACTH) test. Moreover, the presence of gender differences in salivary aldosterone, considering the phase of the menstrual cycle in women, was verified. The sample consisted of 107 volunteers (60 men, 21 women in the follicular phase and 26 women in the luteal phase of the menstrual cycle). Saliva samples were taken by the subjects themselves around 08:00 AM, at least 60 min after awaking. A separate group of female subjects in the follicular phase underwent low-dose ACTH test (1µg synthetic ACTH i.v.) performed at 08:30 AM with blood and saliva sampling every 30 min for 120 min. Modification of the commercial aldosterone radioimmunoassay methodology for the salivary aldosterone measurement was performed. Salivary aldosterone concentrations rose in response to low-dose ACTH test and positive significant correlation in aldosterone concentrations between plasma and saliva was found. The results showed that women in the luteal phase of the menstrual cycle exhibited significantly higher morning concentrations in salivary aldosterone than men and women in the follicular phase. This study clearly demonstrates suitability of measurement of salivary aldosterone concentrations in the low-dose ACTH test and reveals gender differences in salivary aldosterone levels. The results show high validity of the presented method and its usefulness for assessment of the aldosterone concentrations in saliva.

  5. Increased Aldosterone Release During Head-Up Tilt in Early Primary Hypertension.

    PubMed

    Reinold, Annemarie; Schneider, Andreas; Kalizki, Tatjana; Raff, Ulrike; Schneider, Markus P; Schmieder, Roland E; Schmidt, Bernhard M W

    2017-05-01

    Hyperaldosteronism is well known cause of secondary hypertension. However, the importance of aldosterone for the much larger group of patients with primary hypertension is less clear. We hypothesized that in young subjects with primary hypertension, the rise of plasma aldosterone levels in response to head-up tilt testing as a stress stimulus is exaggerated. Hemodynamics (blood pressure (BP), heart rate (HR), cardiac index (CI), and total peripheral vascular resistance index (TPRI), all by TaskForce monitor) and hormones (plasma renin activity (PRA), angiotensin II (Ang II), aldosterone) were measured before and during 30 minutes of head-up tilt in 45 young hypertensive and 45 normotensive subjects. BP, HR, CI, and TPRI all increased in response to head-up tilt, with no difference between groups. There was no difference in baseline PRA, Ang II, and aldosterone between groups. During head-up tilt, PRA, and Ang II levels increased similarly. However, aldosterone levels increased to a greater extent in the hypertensive vs. normotensive subjects (P = 0.0021). Our data suggest that an increased release of aldosterone in response to orthostatic stress is a feature of early primary hypertension. The similar increase in PRA and Ang II suggests a potential role for secretagogues of aldosterone other than Ang II in this response. In addition to its established role in secondary hypertension, dysregulation of aldosterone release might contribute to the development of primary arterial hypertension. © American Journal of Hypertension, Ltd 2017. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  6. Expression analysis of cellulose synthase and main cytoskeletal protein genes in flax (Linum usitatissimum L.).

    PubMed

    Galinousky, Dmitry; Padvitski, Tsimafei; Bayer, Galina; Pirko, Yaroslav; Pydiura, Nikolay; Anisimova, Natallia; Nikitinskaya, Tatyana; Khotyleva, Liubov; Yemets, Alla; Kilchevsky, Aleksandr; Blume, Yaroslav

    2017-08-09

    Fiber flax is an important source of natural fiber and a comprehensive model for the plant fiber biogenesis studies. Cellulose-synthase (CesA) and cytoskeletal genes are known to be important for the cell wall biogenesis in general and for the biogenesis of flax fibers in particular. Currently, knowledge about activity of these genes during the plant growth is limited. In this study, we have investigated flax fiber biogenesis by measuring expression of CesA and cytoskeletal genes at two stages of the flax development (seedlings and stems at the rapid growth stage) in several flax subspecies (elongatum, mediterraneum, crepitans). RT-qPCR has been used to quantify the expression of LusСesA1, LusСesA4, LusСesA7, LusСesA6, Actin, and α-Tubulin genes in plant samples. We report that CesA genes responsible for the secondary cell wall synthesis (LusCesA4, LusCesA7) have different expression pattern compared with CesA genes responsible for the primary cell wall synthesis (LusCesA1, LusCesA6): an average expression of LusCesA4 and LusCesA7 genes is relatively high in seedlings and further increases in stems at the rapid growth stage, whereas an average expression of LusCesA1 and LusCesA6 genes decreases. Interestingly, LusCesA1 is the only studied gene with different expression dynamics between the flax subspecies: its expression decreases by 5.2-10.7 folds in elongatum and mediterraneum but does not change in crepitans subspecies when the rapid growth stage and seedlings are compared. The expression of cytoskeleton genes (coding actin and α-tubulin) is relatively stable and significantly higher than the expression of cellulose-synthase genes in all the studied samples. © 2017 International Federation for Cell Biology.

  7. Expression of inducible nitric oxide synthase in spontaneous bovine bronchopneumonia.

    PubMed

    Fligger, J M; Waldvogel, A S; Pfister, H; Jungi, T W

    1999-09-01

    The expression of inducible nitric oxide synthase (iNOS), major histocompatibility class II molecules (MHC-II), CD68, and the calcium-binding proteins S100A8 and S100A9 (also called MRP8 and MRP14, respectively) was assessed in lung tissues from cattle that succumbed to pneumonia. Expression patterns of these markers were related to the types of lung lesion. iNOS expression was only observed in lungs infected with Arcanobacterium pyogenes or Pasteurella haemolytica but not in lungs from cattle with subacute chronic interstitial pneumonia and acute interstitial pneumonia due to Escherichia coli infection. High levels of iNOS were expressed by cells (probably leukocytes) surrounding necrotic foci. Occasionally, iNOS was expressed by intraalveolar macrophages in viable parenchyma, by leukocytes within the airways, and by some chondrocytes in the supporting cartilage of bronchi. Cells expressing MHC-II were distributed relatively evenly throughout areas of inflammation and did not display any clear association with necrotic foci. Cell types expressing MHC-II included type II alveolar epithelial cells, spindle-shaped cells of the interstitium, cells in bronchus-associated lymphoid tissue, and leukocytes in lymph and blood vessels but largely excluded iNOS-positive cells. Likewise, CD68-positive cells were rarely positive for iNOS and were not confined to the areas surrounding necrotic tissue. As with MHC-II and CD68, there was little if any coexpression of iNOS and either of the S100 proteins tested. Thus, in cattle with necrotizing bronchopneumonia, iNOS-expressing cells were largely restricted to the cellular zone surrounding necrotic areas.

  8. Prognostic significance of thymidylate synthase (TS) expression in cutaneous malignant melanoma.

    PubMed

    Shimizu, A; Kaira, K; Yasuda, M; Asao, T; Ishikawa, O

    2016-01-01

    Thymidylate synthase (TS) plays an essential role in the pathogenesis and development of cancer, and TS-targeting agents have been widely used against different types of cancers. However, it remains still unclear whether or not TS is expressed in malignant melanoma. We conducted the clinicopathological study to investigate the prognostic significance of TS expression in cutaneous malignant melanoma. Ninety-nine patients with surgically resected cutaneous malignant melanoma were assessed. Tumor sections were stained by immunohistochemistry for TS, Ki-67, and microvessel density (MVD) determined by CD34. TS was positively expressed in 26% (26 out of 99). The expression of TS was significantly associated with T factor, cell proliferation (Ki-67) and MVD (CD34). By Spearman's rank test, TS expression was significantly correlated with Ki67 and CD34. By univariate analysis, ulceration, disease stage, TS, Ki-67 and CD34 had a significant relationship with survival. Multivariate analysis confirmed that TS was an independent prognostic factor for poor prognosis of cutaneous malignant melanoma. The positive expression of TS could be a useful marker for predicting poor prognosis in patients with cutaneous malignant melanoma, and TS-targeting agents may be worth trying for the treatment of this dismal disease.

  9. Aldosterone increases cardiac vagal tone via G protein-coupled oestrogen receptor activation

    PubMed Central

    Brailoiu, G Cristina; Benamar, Khalid; Arterburn, Jeffrey B; Gao, Erhe; Rabinowitz, Joseph E; Koch, Walter J; Brailoiu, Eugen

    2013-01-01

    In addition to acting on mineralocorticoid receptors, aldosterone has been recently shown to activate the G protein-coupled oestrogen receptor (GPER) in vascular cells. In light of the newly identified role for GPER in vagal cardiac control, we examined whether or not aldosterone activates GPER in rat nucleus ambiguus. Aldosterone produced a dose-dependent increase in cytosolic Ca2+ concentration in retrogradely labelled cardiac vagal neurons of nucleus ambiguus; the response was abolished by pretreatment with the GPER antagonist G-36, but was not affected by the mineralocorticoid receptor antagonists, spironolactone and eplerenone. In Ca2+-free saline, the response to aldosterone was insensitive to blockade of the Ca2+ release from lysosomes, while it was reduced by blocking the Ca2+ release via ryanodine receptors and abolished by blocking the IP3 receptors. Aldosterone induced Ca2+ influx via P/Q-type Ca2+ channels, but not via L-type and N-type Ca2+ channels. Aldosterone induced depolarization of cardiac vagal neurons of nucleus ambiguus that was sensitive to antagonism of GPER but not of mineralocorticoid receptor. in vivo studies, using telemetric measurement of heart rate, indicate that microinjection of aldosterone into the nucleus ambiguus produced a dose-dependent bradycardia in conscious, freely moving rats. Aldosterone-induced bradycardia was blocked by the GPER antagonist, but not by the mineralocorticoid receptor antagonists. In summary, we report for the first time that aldosterone decreases heart rate by activating GPER in cardiac vagal neurons of nucleus ambiguus. PMID:23878371

  10. Endothelial nitric oxide synthase is dynamically expressed during bone marrow stem cell differentiation into endothelial cells.

    PubMed

    Liu, Zhenguo; Jiang, Yuehua; Hao, Hong; Gupta, Kalpna; Xu, Jian; Chu, Ling; McFalls, Edward; Zweier, Jay; Verfaillie, Catherine; Bache, Robert J

    2007-09-01

    This study was designed to investigate the developmental expression of endothelial nitric oxide synthase (eNOS) during stem cell differentiation into endothelial cells and to examine the functional status of the newly differentiated endothelial cells. Mouse adult multipotent progenitor cells (MAPCs) were used as the source of stem cells and were induced to differentiate into endothelial cells with vascular endothelial growth factor (VEGF) in serum-free medium. Expression of eNOS in the cells during differentiation was evaluated with real-time PCR, nitric oxide synthase (NOS) activity, and Western blot analysis. It was found that eNOS, but no other NOS, was present in undifferentiated MAPCs. eNOS expression disappeared in the cells immediately after induction of differentiation. However, eNOS expression reoccurred at day 7 during differentiation. Increasing eNOS mRNA, protein content, and activity were observed in the cells at days 14 and 21 during differentiation. The differentiated endothelial cells formed dense capillary networks on growth factor-reduced Matrigel. VEGF-stimulated phosphorylation of extracellular signal-regulated kinase (ERK)-1 and ERK-2 occurred in these cells, which was inhibited by NOS inhibitor N(G)-nitro-L-arginine methyl ester. In conclusion, these data demonstrate that eNOS is present in MAPCs and is dynamically expressed during the differentiation of MAPCs into endothelial cells in vitro.

  11. Aldosterone breakthrough during aliskiren, valsartan, and combination (aliskiren + valsartan) therapy.

    PubMed

    Bomback, Andrew S; Rekhtman, Yelena; Klemmer, Philip J; Canetta, Pietro A; Radhakrishnan, Jai; Appel, Gerald B

    2012-01-01

    Aldosterone levels increase in 30%-40% of patients on angiotensin-converting enzyme inhibitors and/or angiotensin receptor blockers over the long term. This "aldosterone breakthrough" may carry important clinical consequences given aldosterone's nonepithelial, pro-fibrotic actions. The renin inhibitor, aliskiren, by suppressing the renin-angiotensin-aldosterone system (RAAS) proximally, may limit breakthrough compared to conventional RAAS blockade. This open-label study (NCT01129557) randomized subjects to aliskiren 300 mg daily (A), valsartan 320 mg daily (V), or aliskiren 150 mg + valsartan 160 mg daily (A+V) for 9 months. Eligible subjects had proteinuria >300 mg/day, estimated glomerular filtration rate (eGFR) >45 mL/min/1.73 m(2), and systolic blood pressure (BP) >130 or diastolic BP >80 mm Hg. Serum and 24-hour urine aldosterone (indexed to 24-hour urine Na) were checked before initiation of therapy and at 3, 6, and 9 months. Aldosterone breakthrough was defined as a sustained increase from baseline aldosterone by study end. The study was intended to enroll 120 subjects but was terminated early by the sponsor. We present here the results of 33 subjects who completed the protocol, of which 12 were randomized to A, 11 were randomized to V, and 10 were randomized to A+V. Mean baseline eGFR was 75.5 (±23.3) mL/min/1.73 m(2); baseline proteinuria was 3104 (±2943) mg/day; and baseline BP was 134.7 (±10.5)/84.8 (±8.4) mm Hg. Three (27%) subjects on V, three (25%) subjects on A, and three (30%) subjects on A+V had aldosterone breakthrough. Mean proteinuria reduction was 31% from baseline in all subjects: 30% in subjects with breakthrough vs. 32% in subjects without breakthrough. Mean BP reduction was 11.0/8.8 mm Hg in all subjects: 8.4/6.1 mm Hg in subjects with breakthrough vs. 12.0/9.8 mm Hg in subjects without breakthrough. Aliskiren, alone or in combination with valsartan, did not reduce the incidence of aldosterone breakthrough in subjects with hypertension

  12. Body Mass Index Predicts 24-Hour Urinary Aldosterone Levels in Patients With Resistant Hypertension.

    PubMed

    Dudenbostel, Tanja; Ghazi, Lama; Liu, Mingchun; Li, Peng; Oparil, Suzanne; Calhoun, David A

    2016-10-01

    Prospective studies indicate that hyperaldosteronism is found in 20% of patients with resistant hypertension. A small number of observational studies in normotensive and hypertensive patients suggest a correlation between aldosterone levels and obesity while others could not confirm these findings. The correlation between aldosterone levels and body mass index (BMI) in patients with resistant hypertension has not been previously investigated. Our objective was to determine whether BMI is positively correlated with plasma aldosterone concentration, plasma renin activity, aldosterone:renin ratio, and 24-hour urinary aldosterone in black and white patients. We performed a cross-sectional analysis of a large diverse cohort (n=2170) with resistant hypertension. The relationship between plasma aldosterone concentration, plasma renin activity, aldosterone:renin ratio, 24-hour urinary aldosterone, and BMI was investigated for the entire cohort, by sex and race (65.3% white, 40.3% men). We demonstrate that plasma aldosterone concentration and aldosterone:renin ratio were significantly correlated to BMI (P<0.0001) across the first 3 quartiles, but not from the 3rd to 4th quartile of BMI. Plasma renin activity was not correlated with BMI. Twenty-four-hour urinary aldosterone was positively correlated across all quartiles of BMI for the cohort (P<0.0001) and when analyzed by sex (men P<0.0001; women P=0.0013) and race (P<0.05), and stronger for men compared with women (r=0.19, P<0.001 versus r=0.05, P=0.431, P=0.028) regardless of race. In both black and white patients, aldosterone levels were positively correlated to increasing BMI, with the correlation being more pronounced in black and white men. These findings suggest that obesity, particularly the abdominal obesity typical of men, contributes to excess aldosterone in patients with resistant hypertension. © 2016 American Heart Association, Inc.

  13. Interactions of NADPH oxidase, renin-angiotensin-aldosterone system and reactive oxygen species in mequindox-mediated aldosterone secretion in Wistar rats.

    PubMed

    Huang, Xian-Ju; Wang, Xu; Ihsan, Awais; Liu, Qin; Xue, Xi-Juan; Su, Shi-Jia; Yang, Chun-Hui; Zhou, Wen; Yuan, Zong-Hui

    2010-10-05

    High doses of mequindox (MEQ) are associated with oxidative stress and pathological toxicity in the kidney. In this study, we demonstrated long term effects of MEQ on intra- or extra-adrenal renin-angiotensin-aldosterone system (RAAS) in vivo. RAAS plays a major role in aldosterone secretion. High doses of MEQ in the diet for 180 days in male rats led to inhibition of intra- and extra-adrenal RAAS, concident with down-regulation of Na(+)/K(+)-ATPase (NAKA) and mineralocorticoid receptor (MR), the downstream of aldosterone action. Significant changes of malondialdehyde (MDA), reduced glutathione (GSH), and superoxide dismutase (SOD) in kidney were also observed in the high doses (110, 275mg/kg) groups. The mRNA levels of most subunits of NADPH oxidase were significantly upregulated at low doses (25-110mg/kg) but the upregulation was diminished at higher doses in both kidney and adrenal gland, indicating a complicated and contradictory effect of MEQ on NADPH. These results highlight the complex interactions of drug metabolism, RAAS, NADPH oxidase and oxidative stress in response to MEQ-induced tissue toxicity and aldosterone secretion. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  14. Adrenal Venous Sampling: Where Is the Aldosterone Disappearing to?

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Solar, Miroslav; Ceral, Jiri, E-mail: ceral.jiri@fnhk.c; Krajina, Antonin

    Adrenal venous sampling (AVS) is generally considered to be the gold standard in distinguishing unilateral and bilateral aldosterone hypersecretion in primary hyperaldosteronism. However, during AVS, we noticed a considerable variability in aldosterone concentrations among samples thought to have come from the right adrenal glands. Some aldosterone concentrations in these samples were even lower than in samples from the inferior vena cava. We hypothesized that the samples with low aldosterone levels were unintentionally taken not from the right adrenal gland, but from hepatic veins. Therefore, we sought to analyze the impact of unintentional cannulation of hepatic veins on AVS. Thirty consecutivemore » patients referred for AVS were enrolled. Hepatic vein sampling was implemented in our standardized AVS protocol. The data were collected and analyzed prospectively. AVS was successful in 27 patients (90%), and hepatic vein cannulation was successful in all procedures performed. Cortisol concentrations were not significantly different between the hepatic vein and inferior vena cava samples, but aldosterone concentrations from hepatic venous blood (median, 17 pmol/l; range, 40-860 pmol/l) were markedly lower than in samples from the inferior vena cava (median, 860 pmol/l; range, 460-4510 pmol/l). The observed difference was statistically significant (P < 0.001). Aldosterone concentrations in the hepatic veins are significantly lower than in venous blood taken from the inferior vena cava. This finding is important for AVS because hepatic veins can easily be mistaken for adrenal veins as a result of their close anatomic proximity.« less

  15. Functional expression of plant acetolactate synthase genes in Escherichia coli

    PubMed Central

    Smith, Julie K.; Schloss, John V.; Mazur, Barbara J.

    1989-01-01

    Acetolactate synthase (ALS; EC 4.1.3.18) is the first common enzyme in the biosynthetic pathways leading to leucine, isoleucine, and valine. It is the target enzyme for three classes of structurally unrelated herbicides, the sulfonylureas, the imidazolinones, and the triazolopyrimidines. A cloned ALS gene from the small cruciferous plant Arabidopsis thaliana has been fused to bacterial transcription/translation signals and the resulting plasmid has been used to transform Escherichia coli. The cloned plant gene, which includes sequences encoding the chloroplast transit peptide, is functionally expressed in the bacteria. It is able to complement genetically a strain of E. coli that lacks endogenous ALS activity. An ALS gene cloned from a line of Arabidopsis previously shown to be resistant to sulfonylurea herbicides has been similarly expressed in E. coli. The herbicide-resistance phenotype is expressed in the bacteria, as assayed by both enzyme activity and the ability to grow in the presence of herbicides. This system has been useful for purifying substantial amounts of the plant enzyme, for studying the sequence parameters involved in subcellular protein localization, and for characterizing the interactions that occur between ALS and its various inhibitors. Images PMID:16594052

  16. Normotensive blood pressure in pregnancy: the role of salt and aldosterone.

    PubMed

    Gennari-Moser, Carine; Escher, Geneviève; Kramer, Simea; Dick, Bernhard; Eisele, Nicole; Baumann, Marc; Raio, Luigi; Frey, Felix J; Surbek, Daniel; Mohaupt, Markus G

    2014-02-01

    A successful pregnancy requires an accommodating environment. Salt and water availability are critical for plasma volume expansion. Any changes in sodium intake would alter aldosterone, a hormone previously described beneficial in pregnancy. To date, it remains ambiguous whether high aldosterone or high salt intake is preferable. We hypothesized that increased aldosterone is a rescue mechanism and appropriate salt availability is equally effective in maintaining a normotensive blood pressure (BP) phenotype in pregnancy. We compared normotensive pregnant women (n=31) throughout pregnancy with young healthy female individuals (n=31-62) and performed salt sensitivity testing within the first trimester. Suppression of urinary tetrahydro-aldosterone levels by salt intake as measured by gas chromatography-mass spectrometry and urinary sodium excretion corrected for creatinine, respectively, was shifted toward a higher salt intake in pregnancy (P<0.0001). In pregnancy, neither high urinary tetrahydro-aldosterone nor sodium excretion was correlated with higher BP. In contrast, in nonpregnant women, systolic BP rose with aldosterone (P<0.05). Testing the impact of salt on BP, we performed salt sensitivity testing in a final cohort of 19 pregnant and 24 nonpregnant women. On salt loading, 24-hour mean arterial pressure rose by 3.6±1.5 and dropped by -2.8±1.5 mm Hg favoring pregnant women (P<0.01; χ(2)=6.04; P<0.02). Our data suggest first that salt responsiveness of aldosterone is alleviated in conditions of pregnancy without causing aldosterone-induced hypertension. Second, salt seems to aid in BP lowering in pregnancy for reasons incompletely elucidated, yet involving renin suppression and potentially placental sensing mechanisms. Further research should identify susceptible individuals and clarify effector mechanisms.

  17. Isolation and functional characterization of a τ-cadinol synthase, a new sesquiterpene synthase from Lavandula angustifolia.

    PubMed

    Jullien, Frédéric; Moja, Sandrine; Bony, Aurélie; Legrand, Sylvain; Petit, Cécile; Benabdelkader, Tarek; Poirot, Kévin; Fiorucci, Sébastien; Guitton, Yann; Nicolè, Florence; Baudino, Sylvie; Magnard, Jean-Louis

    2014-01-01

    In this paper we characterize three sTPSs: a germacrene D (LaGERDS), a (E)-β-caryophyllene (LaCARS) and a τ-cadinol synthase (LaCADS). τ-cadinol synthase is reported here for the first time and its activity was studied in several biological models including transiently or stably transformed tobacco species. Three dimensional structure models of LaCADS and Ocimum basilicum γ-cadinene synthase were built by homology modeling using the template structure of Gossypium arboreum δ-cadinene synthase. The depiction of their active site organization provides evidence of the global influence of the enzymes on the formation of τ-cadinol: instead of a unique amino-acid, the electrostatic properties and solvent accessibility of the whole active site in LaCADS may explain the stabilization of the cadinyl cation intermediate. Quantitative PCR performed from leaves and inflorescences showed two patterns of expression. LaGERDS and LaCARS were mainly expressed during early stages of flower development and, at these stages, transcript levels paralleled the accumulation of the corresponding terpene products (germacrene D and (E)-β-caryophyllene). By contrast, the expression level of LaCADS was constant in leaves and flowers. Phylogenetic analysis provided informative results on potential duplication process leading to sTPS diversification in lavender.

  18. ALDOSTERONE DYSREGULATION WITH AGING PREDICTS RENAL-VASCULAR FUNCTION AND CARDIO-VASCULAR RISK

    PubMed Central

    Brown, Jenifer M.; Underwood, Patricia C.; Ferri, Claudio; Hopkins, Paul N.; Williams, Gordon H.; Adler, Gail K.; Vaidya, Anand

    2014-01-01

    Aging and abnormal aldosterone regulation are both associated with vascular disease. We hypothesized that aldosterone dysregulation influences the age-related risk of renal- and cardio-vascular disease. We conducted an analysis of 562 subjects who underwent detailed investigations under conditions of liberal and restricted dietary sodium intake (1,124 visits) in a Clinical Research Center. Aldosterone regulation was characterized by the ratio of maximal suppression-to-stimulation (supine serum aldosterone on a liberal sodium diet divided by the same measure on a restricted sodium diet). We previously demonstrated that higher levels of this Sodium-modulated Aldosterone Suppression-Stimulation Index (SASSI) indicate greater aldosterone dysregulation. Renal plasma flow (RPF) was determined via p-aminohippurate clearance to assess basal renal hemodynamics, and the renal-vascular responses to dietary sodium manipulation and angiotensin II (AngII) infusion. Cardiovascular risk was calculated using the Framingham Risk Score. In univariate linear regression, older age (β= -4.60, p<0.0001) and higher SASSI (β= -58.63, p=0.001) predicted lower RPF and a blunted RPF response to sodium loading and AngII infusion. We observed a continuous, independent, multivariate-adjusted interaction between age and SASSI, where the inverse relationship between SASSI and RPF was most apparent with older age (p<0.05). Higher SASSI and lower RPF independently predicted higher Framingham Risk Score (p<0.0001) and together displayed an additive effect. Aldosterone regulation and age may interact to mediate renal-vascular disease. Our findings suggest that the combination of aldosterone dysregulation and renal-vascular dysfunction could additively increase the risk of future cardiovascular outcomes; therefore, aldosterone dysregulation may represent a modifiable mechanism of age-related vascular disease. PMID:24664291

  19. Thymidylate synthase (TS) protein expression as a prognostic factor in advanced colorectal cancer: a comparison with TS mRNA expression.

    PubMed

    Nakagawa, Tateo; Shimada, Mitsuo; Kurita, Nobuhiro; Iwata, Takashi; Nishioka, Masanori; Yoshikawa, Kozo; Higashijima, Jun; Utsunomiya, Tohru

    2012-06-01

    The role of intratumoral thymidylate synthase (TS) mRNA or protein expression is still controversial and little has been reported regarding relation of them in colorectal cancer. Forty-six patients with advanced colorectal cancer who underwent surgical resection were included. TS mRNA expression was determined by the Danenberg tumor profile method based on laser-captured micro-dissection of the tumor cells. TS protein expression was evaluated using immunohistochemical staining. TS mRNA expression tended to relate TS protein expression. Statistical significance was not found in overall survival between the TS mRNA high group and low group regardless of performing adjuvant chemotherapy. The overall survival in the TS protein negative group was significantly higher than that in positive group in all and the patients without adjuvant chemotherapy. Multivariate analysis showed TS protein expression was as an independent prognostic factor. TS protein expression tends to be related TS mRNA expression and is an independent prognostic factor in advanced colorectal cancer.

  20. Aldosterone affects blood flow and vascular tone regulated by endothelium-derived NO: therapeutic implications

    PubMed Central

    Toda, Noboru; Nakanishi, Sadanobu; Tanabe, Shinichi

    2013-01-01

    Aldosterone, in doses inappropriate to the salt status, plays an important role in the development of cardiovascular injury, including endothelial dysfunction, independent of its hypertensive effects. Acute non-genomic effects of aldosterone acting on mineralocorticoid receptors are inconsistent in healthy humans: vasoconstriction or forearm blood flow decrease via endothelial dysfunction, vasodilatation mediated by increased NO actions, or no effects. However, in studies with experimental animals, aldosterone mostly enhances vasodilatation mediated by endothelium-derived NO. Chronic exposure to aldosterone, which induces genomic responses, results in impairments of endothelial function through decreased NO synthesis and action in healthy individuals, experimental animals and isolated endothelial cells. Chronic aldosterone reduces NO release from isolated human endothelial cells only when extracellular sodium is raised. Oxidative stress is involved in the impairment of endothelial function by promoting NO degradation. Aldosterone liberates endothelin-1 (ET-1) from endothelial cells, which elicits ETA receptor–mediated vasoconstriction by inhibiting endothelial NO synthesis and action and through its own direct vasoconstrictor action. Ca2+ flux through T-type Ca2+ channels activates aldosterone synthesis and thus enhances unwanted effects of aldosterone on the endothelium. Mineralocorticoid receptor inhibitors, ETA receptor antagonists and T-type Ca2+ channel blockers appear to diminish the pathophysiological participation of aldosterone in cardiovascular disease and exert beneficial actions on bioavailability of endothelium-derived NO, particularly in resistant hypertension and aldosteronism. PMID:23190073

  1. Aldosterone acting through the central nervous system sensitizes angiotensin II-induced hypertension.

    PubMed

    Xue, Baojian; Zhang, Zhongming; Roncari, Camila F; Guo, Fang; Johnson, Alan Kim

    2012-10-01

    Previous studies have shown that preconditioning rats with a nonpressor dose of angiotensin II (Ang II) sensitizes the pressor response produced by later treatment with a higher dose of Ang II and that Ang II and aldosterone (Aldo) can modulate each other's pressor effects through actions involving the central nervous system. The current studies tested whether Aldo can cross-sensitize the pressor actions of Ang II to enhance hypertension by employing an induction-delay-expression experimental design. Male rats were implanted for telemetered blood pressure recording. During induction, subpressor doses of either subcutaneous or intracerebroventricular Aldo were delivered for 1 week. Rats were then rested for 1 week (delay) to assure that any exogenous Aldo was metabolized. After this, Ang II was given subcutaneously for 2 weeks (expression). During induction and delay, Aldo had no sustained effect on blood pressure. However, during expression, Ang II-induced hypertension was greater in the groups receiving subcutaneous or intracerebroventricular Aldo during induction in comparison with those groups receiving vehicle. Central administration of mineralocorticoid receptor antagonist blocked sensitization. Brain tissue collected at the end of delay and expression showed increased mRNA expression of several renin-angiotensin-aldosterone system components in cardiovascular-related forebrain regions of cross-sensitized rats. Cultured subfornical organ neurons preincubated with Aldo displayed greater increases in [Ca2+]i after Ang II treatment, and there was a greater Fra-like immunoreactivity present at the end of expression in cardiovascular-related forebrain structures. Taken together, these results indicate that Aldo pretreatment cross-sensitizes the development of Ang II-induced hypertension probably by mechanisms that involve the central nervous system.

  2. New Sides of Aldosterone Action in Cardiovascular System as Potential Targets for Therapeutic Intervention.

    PubMed

    Kolodziejczyk, Patrycjusz; Gromotowicz-Poplawska, Anna; Aleksiejczuk, Michal; Chabielska, Ewa; Tutka, Piotr; Miltyk, Wojciech

    2018-03-26

    Aldosterone, the main mineralocorticoid hormone, plays a crucial role in the regulation of electrolyte homeostasis and blood pressure. Although, this role is undoubtedly important, it is not a hormonal action that attracts the most attention. Aldosterone seems to be very important important as a local messenger in the pathology of cardiovascular diseases (CVD). In the last few years, the attention was focused on the correlation between raised aldosterone level and increased risk of cardiovascular events. It has been demonstrated that aldosterone contributes to fibrosis, inflammation, endothelial dysfunction, fibrinolytic disordes, and oxidative stress leading to CVD development and progression. It used to be thought that the effects of aldosterone are mediated via classic nuclear receptors - mineralocorticoid receptors (MR). Now we know that the mechanism of aldosterone action in cardiovascular system is much more complex, since experimental and clinical studies indicate that MR blockade may be not sufficient to abolish aldosterone-incuced harmful effects in the cardiovascular system. Therefore, the involvement of some other than MR, receptors and factors is suggested. Moreover, in addition to the generally known genomic action of aldosterone, which involves MR activation, the nongenomic pathways are postulated in the mode of hormone action. More and more attention is focused on the membrane-coupled receptors, which mediate the rapid effects of aldosterone and have been already confirmed in different cells and tissues of a cardiovascular system. The confirmation of multiple mechanisms of aldosterone action opens a new perspective for more effective therapeutic intervention in aldosterone-related CVD. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. Body mass index predicts aldosterone production in normotensive adults on a high-salt diet.

    PubMed

    Bentley-Lewis, Rhonda; Adler, Gail K; Perlstein, Todd; Seely, Ellen W; Hopkins, Paul N; Williams, Gordon H; Garg, Rajesh

    2007-11-01

    The mechanisms underlying obesity-mediated cardiovascular disease are not fully understood. Aldosterone and insulin resistance both are associated with obesity and cardiovascular disease. The objectives of this study were to test the hypotheses that aldosterone production is elevated and associated with insulin resistance in overweight adults on a high-sodium diet. Healthy normotensive adults were categorized as lean body mass index (BMI) less than 25 kg/m(2) (n = 63) or overweight BMI 25 kg/m(2) or greater (n = 57). After 7 d of a high-sodium diet, participants fasted overnight and remained supine throughout hemodynamic and laboratory assessments and angiotensin II (AngII) stimulation. The overweight group, compared with the lean group, had higher 24-h urinary aldosterone (9.0 +/- 0.8 vs. 6.6 +/- 0.5 microg per 24 h; P = 0.003) and higher AngII-stimulated serum aldosterone (11.4 +/- 1.0 vs. 9.0 +/- 0.6 ng/dl; P = 0.04). There were no differences in 24-h urinary cortisol or sodium or supine measurements of plasma renin activity, serum aldosterone, or serum potassium. The homeostasis model assessment of insulin resistance was predicted by urinary aldosterone excretion (r = 0.32, P = 0.03) and serum aldosterone response to AngII stimulation (r = 0.28, P = 0.02) independent of age and BMI. Urinary aldosterone excretion and AngII-stimulated aldosterone are increased in overweight, compared with lean, normotensive adults. The correlation of these measures of aldosterone production with insulin resistance suggests a potential role for aldosterone in the pathophysiology of obesity-mediated insulin resistance.

  4. Adrenalectomy amplifies aldosterone induced injury in cardiovascular tissue: an effect attenuated by adrenally derived steroids.

    PubMed

    Brem, Andrew S; Morris, David J; Li, Xiangpo; Ge, Yan; Shaw, Sunil; Gong, Rujun

    2013-03-01

    Aldosterone induces fibrotic changes in cardiovascular tissues but its effects have usually been demonstrated in models of pre-existing renal injury and/or hypertension. This study tests the hypothesis that aldosterone can directly induce vascular fibrotic changes in the absence of prior renal injury or hypertension. Experiments were conducted in intact or adrenalectomized (ADX) mice. Mice were divided into groups and treated for 1 week with vehicle or aldosterone (8 μg/kg/day)± inhibitor (800 μg/kg/day): CONTROLS, mice treated with aldosterone, ADX-CONTROLS, ADX+corticosterone (CORT 8 μg/kg/day), ADX with aldosterone, ADX with aldosterone plus the mineralocorticoid receptor (MR) antagonist RU-318, ADX with aldosterone+CORT (CORT inhibitor dose), and ADX with aldosterone+11-dehydro-CORT. Aortic smooth muscle to collagen ratio, aorta intimal thickness (μm), heart weight/body weight ratio (mg/gm), and left ventricular collagen (%) were measured. Prior to sacrifice, blood pressures were normal in all animals. Lower dose CORT alone had no effect on any of the variables examined. Aldosterone exposure was associated with extra-cellular matrix accumulation in cardiovascular tissues in intact mice and adrenalectomy exacerbated these effects. RU-318, CORT (inhibitor dose), and 11-deydro-CORT each attenuated the early fibrotic changes induced by aldosterone. In the heart, aldosterone exposure affected all the parameters measured and caused intimal hypercellularity with monocytes adhering to endothelial cells lining coronary vessels. Cultured endothelial cells exposed to aldosterone (10nM) released E-selectin, produced collagen, and promoted monocyte adhesion. These effects were inhibited by RU-318 and 11-deydro-CORT but not by CORT. Thus, adrenalectomy enhances aldosterone induced early fibrotic changes in heart and aorta. Aldosterone initially targets vascular endothelial cells. MR antagonists and 11-dehydro-CORT, an 11β-HSD dehydrogenase end-product, directly

  5. SFE/SFHTA/AFCE consensus on primary aldosteronism, part 4: Subtype diagnosis.

    PubMed

    Bardet, Stéphane; Chamontin, Bernard; Douillard, Claire; Pagny, Jean-Yves; Hernigou, Anne; Joffre, Francis; Plouin, Pierre-François; Steichen, Olivier

    2016-07-01

    To establish the cause of primary aldosteronism (PA), it is essential to distinguish unilateral from bilateral adrenal aldosterone secretion, as adrenalectomy improves aldosterone secretion and controls hypertension and hypokalemia only in the former. Except in the rare cases of type 1 or 3 familial hyperaldosteronism, which can be diagnosed genetically and are not candidates for surgery, lateralized aldosterone secretion is diagnosed on adrenal CT or MRI and adrenal venous sampling. Postural stimulation tests and (131)I-norcholesterol scintigraphy have poor diagnostic value and (11)C-metomidate PET is not yet available. We recommend that adrenal CT or MRI be performed in all cases of PA. Imaging may exceptionally identify adrenocortical carcinoma, for which the surgical objectives are carcinologic, and otherwise shows either normal or hyperplastic adrenals or unilateral adenoma. Imaging alone carries a risk of false positives in patients over 35 years of age (non-aldosterone-secreting adenoma) and false negatives in all patients (unilateral hyperplasia). We suggest that all candidates for surgery over 35 years of age undergo adrenal venous sampling, simultaneously in both adrenal veins, without ACTH stimulation, to confirm the unilateral form of the hypersecretion. Sampling results should be confirmed on adrenal vein cortisol assay showing a concentration at least double that found in peripheral veins. Aldosterone secretion should be considered lateralized when aldosterone/cortisol ratio on the dominant side is at least 4-fold higher than contralaterally. Published by Elsevier Masson SAS.

  6. Expression of endothelin-1 and constitutional nitric oxide synthase messenger RNA in saphenous vein endothelial cells exposed to arterial flow shear stress.

    PubMed

    Zhu, Z G; Li, H H; Zhang, B R

    1997-11-01

    It has long been speculated that increased blood flow shear stress might be one of the major factors affecting the patency of grafted saphenous vein in coronary artery bypass operations. The underlying cellular and molecular mechanisms for so-called "shear stress damage" have not yet been well elucidated. Endothelial cells harvested from human saphenous vein were cultured in vitro and then exposed to a high arterial level flow shear stress in the parallel flow chamber. The expression levels of endothelin-1 and constitutional nitric oxide synthase by the endothelial cells were evaluated semiquantitatively at the gene transcription (messenger RNA) level using reverse transcription polymerase chain reaction. After 7 hours of exposure to arterial level shear stress, the expression of constitutional nitric oxide synthase messenger RNA by saphenous vein endothelial cells was significantly reduced, whereas the expression of endothelin-1 messenger RNA was substantially increased. These changes were more predominant at 24 hours. Arterial level flow shear stress could cause important changes in the gene transcription level in saphenous vein endothelial cells within a short period of time. The functional alterations of saphenous vein endothelial cells, as manifested by the increased expression of endothelin-1 and decreased expression of nitric oxide synthase messenger RNA, might play a crucial role in the vein graft remodeling process.

  7. Update in diagnosis and management of primary aldosteronism.

    PubMed

    Dick, Sofia M; Queiroz, Marina; Bernardi, Bárbara L; Dall'Agnol, Angélica; Brondani, Letícia A; Silveiro, Sandra P

    2018-02-23

    Primary aldosteronism (PA) is a group of disorders in which aldosterone is excessively produced. These disorders can lead to hypertension, hypokalemia, hypervolemia and metabolic alkalosis. The prevalence of PA ranges from 5% to 12% around the globe, and the most common causes are adrenal adenoma and adrenal hyperplasia. The importance of PA recognition arises from the fact that it can have a remarkably adverse cardiovascular and renal impact, which can even result in death. The aldosterone-to-renin ratio (ARR) is the election test for screening PA, and one of the confirmatory tests, such as oral sodium loading (OSL) or saline infusion test (SIT), is in general necessary to confirm the diagnosis. The distinction between adrenal hyperplasia (AH) or aldosterone-producing adenoma (APA) is essential to select the appropriate treatment. Therefore, in order to identify the subtype of PA, imaging exams such as computed tomography or magnetic ressonance imaging, and/or invasive investigation such as adrenal catheterization must be performed. According to the subtype of PA, optimal treatment - surgical for APA or pharmacological for AH, with drugs like spironolactone and amiloride - must be offered.

  8. Rapid actions of aldosterone revisited: Receptors in the limelight.

    PubMed

    Wehling, Martin

    2018-02-01

    Steroid hormones like aldosterone have been conclusively shown to elicit both late genomic and rapid, nongenomically initiated responses. Aldosterone was among the first for which rapid, clinically relevant effects were even shown in humans. Yet, after over 30 years of research, the nature of receptors involved in rapid actions of aldosterone is still unclear. Such effects may be assigned to the classical, intracellular steroid receptors, in this case mineralocorticoid receptors (MR, class IIa action Mannheim classification). They typically disappear in knockout models and are blocked by MR-antagonists such as spironolactone, as shown for several cellular and physiological, e.g. renal or cardiovascular effects. In contrast, there is also consistent evidence suggesting type IIb effects involving structurally different receptors ("membrane receptors") being insensitive to classic antagonists and persistent in knockout models; IIb effects have lately even been confirmed by atomic force detection of surface receptors which bind aldosterone but not spironolactone. Type IIa and b may coexist in the same cell with IIa often augmenting early IIb effects. So far cloning of IIb receptors was unsuccessful; therefore results on G-protein coupled estrogen receptor 1 (GPER1) being potentially involved in rapid aldosterone action raised considerable interest. Surprisingly, GPER1 does not bind aldosterone. Though under these circumstances GPER1 should not yet be considered as IIb-receptor, it might be an intermediary signaling enhancer of mineralocorticoid action as shown for epithelial growth factor receptors reconciling those results. We still seem to be left without IIb-receptors whose identification would however be highly desirable and essential for clinical translation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Impact of aldosterone-producing cell clusters on diagnostic discrepancies in primary aldosteronism

    PubMed Central

    Kometani, Mitsuhiro; Yoneda, Takashi; Aono, Daisuke; Karashima, Shigehiro; Demura, Masashi; Nishimoto, Koshiro; Yamagishi, Masakazu; Takeda, Yoshiyu

    2018-01-01

    Adrenocorticotropic hormone (ACTH) stimulation is recommended in adrenal vein sampling (AVS) for primary aldosteronism (PA) to improve the AVS success rate. However, this method can confound the subtype diagnosis. Gene mutations or pathological characteristics may be related to lateralization by AVS. This study aimed to compare the rate of diagnostic discrepancy by AVS pre- versus post-ACTH stimulation and to investigate the relationship between this discrepancy and findings from immunohistochemical and genetic analyses of PA. We evaluated 195 cases of AVS performed in 2011–2017. All surgical specimens were analyzed genetically and immunohistochemically. Based on the criteria, AVS was successful in 158 patients both pre- and post-ACTH; of these patients, 75 showed diagnostic discrepancies between pre- and post-ACTH. Thus, 19 patients underwent unilateral adrenalectomy, of whom 16 had an aldosterone-producing adenoma (APA) that was positive for CYP11B2 immunostaining. Of them, 10 patients had discordant lateralization between pre- and post-ACTH. In the genetic analysis, the rate of somatic mutations was not significantly different between APA patients with versus without a diagnostic discrepancy. In the immunohistochemical analysis, CYP11B2 levels and the frequency of aldosterone-producing cell clusters (APCCs) in APAs were almost identical between patients with versus without a diagnostic discrepancy. However, both the number and summed area of APCCs in APAs were significantly smaller in patients with concordant results than in those whose diagnosis changed to bilateral PA post-ACTH stimulation. In conclusion, lateralization by AVS was affected by APCCs in the adjacent gland, but not by APA-related factors such as somatic gene mutations. PMID:29899838

  10. The role of aldosterone antagonism agents in diabetic kidney disease.

    PubMed

    Wombwell, Eric; Naglich, Andrew

    2015-03-01

    Diabetic kidney disease is a common consequence of the development of diabetes. In the United Kingdom 18-30% of chronic kidney disease cases and 44% of end-stage renal disease cases in the United States have been attributed to complications of diabetic kidney disease. Angiotensin blockade using angiotensin converting enzyme inhibitors or angiotensin receptor blockers is the standard for slowing the progression of diabetic kidney disease. Evidence suggests that aldosterone antagonism added to standard therapy may be beneficial. This paper aims to explore the pathophysiological contribution of aldosterone in diabetic kidney disease and review available literature for aldosterone antagonism through mineralocorticoid receptor blockade. A comprehensive literature search was conducted. Results were analysed and summarised. Nine trials evaluating a total of 535 patients with diabetic kidney disease were identified that evaluated the use of aldosterone antagonists for reducing the signs of diabetic kidney disease. All trials demonstrated a marked decrease in urinary protein excretion when compared to, or added to angiotensin converting enzyme inhibition or angiotensin receptor blockade. The most commonly reported side effect in all of the trials was hyperkalaemia, which occurred in 6.1% of all patients evaluated. Aldosterone antagonists were generally well tolerated in the evaluated patient populations. Aldosterone antagonism may represent a safe and effective complimentary therapy to the use of angiotensin converting enzyme inhibition, or angiotensin receptor blockade, for slowing the progression of diabetic kidney disease. © 2014 European Dialysis and Transplant Nurses Association/European Renal Care Association.

  11. Aldosterone antagonists: effective add-on therapy for the treatment of resistant hypertension.

    PubMed

    Gaddam, Krishna K; Pratt-Ubunama, Monique N; Calhoun, David A

    2006-05-01

    Resistant hypertension is defined as blood pressure that remains above target levels despite treatment with three different antihypertensive agents. Cross-sectional analyses and hypertension outcome studies indicate that it is a common clinical problem, which will undoubtedly become increasingly prevalent with an aging and increasingly overweight population. Secondary causes of hypertension are common in patients with resistant hypertension, particularly hyperaldosteronism, with a prevalence of approximately 15-20%. This, however, is likely to be an underestimation of the role excess aldosterone plays in causing resistance to treatment. In subjects with resistant hypertension, suppressed renin levels are common, exceeding 60% in studies conducted by the authors and from centers elsewhere in the world, suggesting occurrence of excess aldosterone beyond cases of true primary aldosteronism. Recent clinical studies indicate that aldosterone antagonists provide significant additional blood pressure reduction when added to treatment regimens of patients with resistant hypertension independent of aldosterone levels. These agents are generally well tolerated. Hyperkalemia is an uncommon complication of aldosterone antagonists, but it can occur. Therefore, biochemical monitoring is necessary, particularly in high-risk patients.

  12. Aldosterone rapidly activates Src kinase in M-1 cells involving the mineralocorticoid receptor and HSP84.

    PubMed

    Braun, Sabine; Lösel, Ralf; Wehling, Martin; Boldyreff, Brigitte

    2004-07-16

    We investigated the effect of aldosterone on Src kinase. In the kidney cell line, M-1 aldosterone leads to a >2-fold transient activation of Src kinase seen as early as 2 min after aldosterone administration. Maximal Src kinase activation was measured at an aldosterone concentration of 1 nM. In parallel to activation, autophosphorylation at Tyr-416 of Src kinase increased. Src kinase activation was blocked by spironolactone. Aldosterone led to increased association of Src with HSP84. Furthermore, rapamycin blocked aldosterone-induced Src activation. We conclude that Src activation by aldosterone is mediated through the mineralocorticoid receptor and HSP84.

  13. Aldosterone interaction with epidermal growth factor receptor signaling in MDCK cells.

    PubMed

    Gekle, Michael; Freudinger, Ruth; Mildenberger, Sigrid; Silbernagl, Stefan

    2002-04-01

    Epidermal growth factor (EGF) regulates cell proliferation, differentiation, and ion transport by using extracellular signal-regulated kinase (ERK)1/2 as a downstream signal. Furthermore, the EGF-receptor (EGF-R) is involved in signaling by G protein-coupled receptors, growth hormone, and cytokines by means of transactivation. It has been suggested that steroids interact with peptide hormones, in part, by rapid, potentially nongenomic, mechanisms. Previously, we have shown that aldosterone modulates Na(+)/H(+) exchange in Madin-Darby canine kidney (MDCK) cells by means of ERK1/2 in a way similar to growth factors. Here, we tested the hypothesis that aldosterone uses the EGF-R as a heterologous signal transducer in MDCK cells. Nanomolar concentrations of aldosterone induce a rapid increase in ERK1/2 phosphorylation, cellular Ca(2+) concentration, and Na(+)/H(+) exchange activity similar to increases induced by EGF. Furthermore, aldosterone induced a rapid increase in EGF-R-Tyr phosphorylation, and inhibition of EGF-R kinase abolished aldosterone-induced signaling. Inhibition of ERK1/2 phosphorylation reduced the Ca(2+) response, whereas prevention of Ca(2+) influx did not abolish ERK1/2 phosphorylation. Our data show that aldosterone uses the EGF-R-ERK1/2 signaling cascade to elicit its rapid effects in MDCK cells.

  14. Functional characterization and expression of GASCL1 and GASCL2, two anther-specific chalcone synthase like enzymes from Gerbera hybrida.

    PubMed

    Kontturi, Juha; Osama, Raisa; Deng, Xianbao; Bashandy, Hany; Albert, Victor A; Teeri, Teemu H

    2017-02-01

    The chalcone synthase superfamily consists of type III polyketidesynthases (PKSs), enzymes responsible for producing plant secondary metabolites with various biological and pharmacological activities. Anther-specific chalcone synthase-like enzymes (ASCLs) represent an ancient group of type III PKSs involved in the biosynthesis of sporopollenin, the main component of the exine layer of moss spores and mature pollen grains of seed plants. In the latter, ASCL proteins are localized in the tapetal cells of the anther where they participate in sporopollenin biosynthesis and exine formation within the locule. It is thought that the enzymes responsible for sporopollenin biosynthesis are highly conserved, and thus far, each angiosperm species with a genome sequenced has possessed two ASCL genes, which in Arabidopsis thaliana are PKSA and PKSB. The Gerbera hybrida (gerbera) PKS protein family consists of three chalcone synthases (GCHS1, GCHS3 and GCHS4) and three 2-pyrone synthases (G2PS1, G2PS2 and G2PS3). In previous studies we have demonstrated the functions of chalcone synthases in flavonoid biosynthesis, and the involvement of 2-pyrone synthases in the biosynthesis of antimicrobial compounds found in gerbera. In this study we expanded the gerbera PKS-family by functionally characterizing two gerbera ASCL proteins. In vitro enzymatic studies using purified recombinant proteins showed that both GASCL1 and GASCL2 were able to use medium and long-chain acyl-CoA starters and perform two to three condensation reactions of malonyl-CoA to produce tri- and tetraketide 2-pyrones, usually referred to as alpha-pyrones in sporopollenin literature. Both GASCL1 and GASCL2 genes were expressed only in floral organs, with most expression observed in anthers. In the anthers, transcripts of both genes showed strict tapetum-specific localization. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Zero gravity and cardiovascular homeostasis. The relationship between endogenous hyperprolactinemia and plasma aldosterone

    NASA Technical Reports Server (NTRS)

    Haber, E.; Re, R. N.; Kourides, I. A.; Weihl, A. C.; Maloof, F.

    1978-01-01

    Prolactin, thyrotropin and aldosterone were measured by radioimmunoassay and plasma renin activity by the radioimmunoassay of angiotensin I in normal women before and after the intravenous injection of 200 micrograms of thyrotropin releasing hormone. Prolactin increased at 15 minutes following thyrotropin releasing hormone. Plasma renin activity was not different from control levels during the first hour following the administration of thyrotropin releasing hormone, nor did the plasma aldosterone concentration differ significantly from the control levels during this period. However, with upright posture, an increase in aldosterone and in plasma renin activity was noted, demonstrating a normal capacity to secrete aldosterone. Similarly, no change in aldosterone was seen in 9 patients with primary hypothyroidism given thyrotropin releasing hormone, despite the fact that the increase in prolactin was greater than normal. These data demonstrate that acutely or chronically elevated serum prolactin levels do not result in increased plasma aldosterone levels in humans.

  16. An In Planta-Expressed Polyketide Synthase Produces (R)-Mellein in the Wheat Pathogen Parastagonospora nodorum

    PubMed Central

    Krill, Christian; Barrow, Russell A.; Chen, Shasha; Trengove, Robert; Oliver, Richard P.; Solomon, Peter S.

    2014-01-01

    Parastagonospora nodorum is a pathogen of wheat that affects yields globally. Previous transcriptional analysis identified a partially reducing polyketide synthase (PR-PKS) gene, SNOG_00477 (SN477), in P. nodorum that is highly upregulated during infection of wheat leaves. Disruption of the corresponding SN477 gene resulted in the loss of production of two compounds, which we identified as (R)-mellein and (R)-O-methylmellein. Using a Saccharomyces cerevisiae yeast heterologous expression system, we successfully demonstrated that SN477 is the only enzyme required for the production of (R)-mellein. This is the first identification of a fungal PKS that is responsible for the synthesis of (R)-mellein. The P. nodorum ΔSN477 mutant did not show any significant difference from the wild-type strain in its virulence against wheat. However, (R)-mellein at 200 μg/ml inhibited the germination of wheat (Triticum aestivum) and barrel medic (Medicago truncatula) seeds. Comparative sequence analysis identified the presence of mellein synthase (MLNS) homologues in several Dothideomycetes and two sodariomycete genera. Phylogenetic analysis suggests that the MLNSs in fungi and bacteria evolved convergently from fungal and bacterial 6-methylsalicylic acid synthases. PMID:25326302

  17. Diagnostic rate of primary aldosteronism in Emilia-Romagna, Northern Italy, during 16 years (2000-2015).

    PubMed

    Rossi, Ermanno; Perazzoli, Franco; Negro, Aurelio; Magnani, Antonia

    2017-08-01

    Although primary aldosteronism is considered the most common form of endocrine hypertension, the diagnostic rate of primary aldosteronism in the territory is unknown. The aims of the current study were to compare the number of patients discharged with International Classification of Diseases 9 Clinical Modification codes compatible with primary aldosteronism from all the hospitals in Emilia-Romagna during 16 years (from 2000 to 2015) with the number of expected cases of primary aldosteronism, and to compare the number of patients with primary aldosteronism who underwent adrenalectomy in the period 2000-2015 with the number of expected cases of unilateral primary aldosteronism. We accessed the Database of the Emilia-Romagna Health Service to select all patients from the age of 20 years discharged with International Classification of Diseases 9 Clinical Modification codes compatible with primary aldosteronism and, among them, those who underwent adrenalectomy in the same period. The prevalence of hypertension in Emilia-Romagna from the age of 20 years was drawn from the Health Search Database. The population from the age of 20 years in Emilia-Romagna has been drawn from the Italian National Statistical Institute. We hypothesized a prevalence of primary aldosteronism of 5% among hypertensive patients and a prevalence of unilateral subtypes of 30% among the primary aldosteronism patients. A total of 992 patients have been discharged with codes consistent with primary aldosteronism during 16 years in Emilia-Romagna, that is 1.9% of the expected cases of primary aldosteronism. A total of 160 of them underwent adrenalectomy in the same period, which corresponds to 1% of the expected cases of unilateral primary aldosteronism in Emilia-Romagna. Our results clearly indicate that primary aldosteronism is dramatically underdiagnosed and undertreated.

  18. Aldosterone alters the chromatin structure of the murine endothelin-1 gene.

    PubMed

    Welch, Amanda K; Jeanette Lynch, I; Gumz, Michelle L; Cain, Brian D; Wingo, Charles S

    2016-08-15

    Aldosterone increases sodium reabsorption in the renal collecting duct and systemic blood pressure. Paradoxically, aldosterone also induces transcription of the endothelin-1 (Edn1) gene to increase protein (ET-1) levels, which inhibits sodium reabsorption. Here we investigated changes in the chromatin structure of the Edn1 gene of collecting duct cell lines in response to aldosterone treatment. The Edn1 gene has a CpG island that encompasses the transcription start site and four sites in the 5' regulatory region previously linked to transcriptional regulation. The chromatin structure of the Edn1 gene was investigated using a quantitative PCR-based DNaseI hypersensitivity assay in murine hepatocyte (AML12), renal cortical collecting duct (mpkCCDC14), outer medullary collecting duct1 (OMCD1), and inner medullary collecting duct-3 (IMCD-3) cell lines. The CpG island was uniformly accessible. One calcium-responsive NFAT element remained at low chromatin accessibility in all cell lines under all conditions tested. However, the second calcium responsive NFAT element located at -1563bp upstream became markedly more accessible in IMCD-3 cells exposed to aldosterone. Importantly, one established aldosterone hormone response element HRE at -671bp relative to the transcription start site was highly accessible, and another HRE (-551bp) became more accessible in aldosterone-treated IMCD-3 and OMCD1 cells. The evidence supports a model in which aldosterone activation of the mineralocorticoid receptor (MR) results in the MR-hormone complex binding at HRE at -671bp to open chromatin structure around other regulatory elements in the Edn1 gene. Published by Elsevier Inc.

  19. A phycocyanin·phellandrene synthase fusion enhances recombinant protein expression and β-phellandrene (monoterpene) hydrocarbons production in Synechocystis (cyanobacteria).

    PubMed

    Formighieri, Cinzia; Melis, Anastasios

    2015-11-01

    Cyanobacteria can be exploited as photosynthetic platforms for heterologous generation of terpene hydrocarbons with industrial applications. Transformation of Synechocystis and heterologous expression of the β-phellandrene synthase (PHLS) gene alone is necessary and sufficient to confer to Synechocystis the ability to divert intermediate terpenoid metabolites and to generate the monoterpene β-phellandrene during photosynthesis. However, terpene synthases, including the PHLS, have a slow Kcat (low Vmax) necessitating high levels of enzyme concentration to enable meaningful rates and yield of product formation. Here, a novel approach was applied to increase the PHLS protein expression alleviating limitations in the rate and yield of β-phellandrene product generation. Different PHLS fusion constructs were generated with the Synechocystis endogenous cpcB sequence, encoding for the abundant in cyanobacteria phycocyanin β-subunit, expressed under the native cpc operon promoter. In one of these constructs, the CpcB·PHLS fusion protein accumulated to levels approaching 20% of the total cellular protein, i.e., substantially higher than expressing the PHLS protein alone under the same endogenous cpc promoter. The CpcB·PHLS fusion protein retained the activity of the PHLS enzyme and catalyzed β-phellandrene synthesis, yielding an average of 3.2 mg product g(-1) dry cell weight (dcw) versus the 0.03 mg g(-1)dcw measured with low-expressing constructs, i.e., a 100-fold yield improvement. In conclusion, the terpene synthase fusion-protein approach is promising, as, in this case, it substantially increased the amount of the PHLS in cyanobacteria, and commensurately improved rates and yield of β-phellandrene hydrocarbons production in these photosynthetic microorganisms. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  20. The therapeutic potential of renin angiotensin aldosterone system (RAAS) in chronic pain: from preclinical studies to clinical trials.

    PubMed

    Bessaguet, Flavien; Magy, Laurent; Desmoulière, Alexis; Demiot, Claire

    2016-01-01

    The prevalence rate of chronic pain is 15% to 25% in adults while the therapeutic arsenal is still insufficient, especially in relieving neuropathic pain. Peripheral pain transmission is conducted by the small Aδ and C sensory nerve fibres. They express elements from the renin-angiotensin-aldosterone system (RAAS), a well-known blood pressure regulator. Recently, studies have demonstrated the role of angiotensin II, its derivatives and aldosterone in the modulation of pain perception, by interacting with receptors expressed by sensory nerve fibres or through the central nervous system. Here, we assess the effects of RAAS modulators in the conduction of pain with molecular, preclinical and clinical approaches, in normal or pathological conditions. Currently, some clinical studies have been carried out on the pain-relieving effect of RAAS modulators and suggest their potential in the management of chronic, inflammatory or neuropathic pain.

  1. Effect of all-trans retinoic acid treatment on prohibitin and renin-angiotensin-aldosterone system expression in hypoxia-induced renal tubular epithelial cell injury.

    PubMed

    Zhou, Tian-Biao; Ou, Chao; Rong, Liang; Drummen, Gregor P C

    2014-09-01

    All-trans retinoic acid (ATRA) exerts various effects on physiological processes such as cell growth, differentiation, apoptosis and inflammation. Prohibitins (PHB), including prohibitin 1 (PHB1) and prohibitin 2 (PHB2), are evolutionary conserved and pleiotropic proteins implicated in various cellular functions, including proliferation, tumor suppression, apoptosis, transcription, and mitochondrial protein folding. The renin-angiotensin-aldosterone system plays a pivotal role in the regulation of blood pressure and volume homeostasis. All these factors and systems have been implicated in renal interstitial fibrosis. Therefore, the objective of this study was to investigate the effect of ATRA treatment on the renin-angiotensin-aldosterone system and expression of prohibitins to further understand its role in the processes leading to renal interstitial fibrosis. The hypoxic and oxidative stress conditions in obstructive renal disease were simulated in a hypoxia/reoxygenation model with renal tubular epithelial cells (RTEC) as a model system. Subsequently, the effect of ATRA on mRNA and protein expression levels was determined and correlations were established between factors involved in the renin-angiotensin-aldosterone system, the prohibitins, cellular redox status, renal interstitial fibrosis and ATRA treatment. Correlation analysis showed that both PHB1 and PHB2 protein levels were negatively correlated with angiotensin I, ACE1, angiotensin II, TGF-β1, Col-IV, FN, ROS, and MDA (PHB1: r = -0.792, -0.834, -0.805, -0.795, -0.778, -0.798, -0.751, -0.682; PHB2: r = -0.872, -0.799, -0.838, -0.773, -0.769, -0.841, -0.794, -0.826; each p < 0.05), but positively correlated with ACE2, SOD, and GSH (PHB1: r = 0.796, 0.879, 0.824; PHB2: r = 0.785, 0.914, 0.849; each p < 0.05). ACE1 was positively correlated with angiotensin I, angiotensin II, TGF-β1, Col-IV, FN, ROS, and MDA, and negatively correlated with ACE2, SOD, and GSH (each p < 0.05). ACE2 was negatively correlated

  2. Plasma aldosterone and sweat sodium concentrations after exercise and heat acclimation

    NASA Technical Reports Server (NTRS)

    Kirby, C. R.; Convertino, V. A.

    1986-01-01

    The relationship between plasma aldosterone levels and sweat sodium excretion after chronic exercise and heat acclimation was investigated, using subjects exercised, at 40 C and 45 percent humidity, for 2 h/day on ten consecutive days at 45 percent of their maximal oxygen uptake. The data indicate that, following heat acclimation, plasma aldosterone concentrations decrease, and that the eccrine gland responsiveness to aldosterone, as represented by sweat sodium reabsorption, may be augmented through exercise and heat acclimation.

  3. Nitric oxide synthase 2 (NOS2) expression in histologically normal margins of oral squamous cell carcinoma

    PubMed Central

    Itoiz, María E.; Guiñazú, Natalia; Piccini, Daniel; Gea, Susana; López-de Blanc, Silvia

    2014-01-01

    The activity of Nitric Oxide Synthase 2 (NOS2) was found in oral squamous cell carcinomas (OSCC) but not in normal mucosa. Molecular changes associated to early carcinogenesis have been found in mucosa near carcinomas, which is considered a model to study field cancerization. The aim of the present study is to analyze NOS2 expression at the histologically normal margins of OSCC. Study Design: Eleven biopsy specimens of OSCC containing histologically normal margins (HNM) were analyzed. Ten biopsies of normal oral mucosa were used as controls. The activity of NOS2 was determined by immunohistochemistry. Salivary nitrate and nitrite as well as tobacco and alcohol consumption were also analyzed. The Chi-squared test was applied. Results: Six out of the eleven HNM from carcinoma samples showed positive NOS2 activity whereas all the control group samples yielded negative (p=0.005). No statistically significant association between enzyme expression and tobacco and/or alcohol consumption and salivary nitrate and nitrite was found. Conclusions: NOS2 expression would be an additional evidence of alterations that may occur in a state of field cancerization before the appearance of potentially malignant morphological changes. Key words:Field cancerization, oral squamous cell carcinoma, Nitric Oxide Synthase 2 (NOS2), malignity markers. PMID:24316703

  4. Metoclopramide unmasks potentially misleading contralateral suppression in patients undergoing adrenal vein sampling for primary aldosteronism.

    PubMed

    Rossitto, Giacomo; Miotto, Diego; Battistel, Michele; Barbiero, Giulio; Maiolino, Giuseppe; Bisogni, Valeria; Sanga, Viola; Rossi, Gian Paolo

    2016-11-01

    As metoclopramide stimulates aldosterone secretion, we tested its usefulness in the assessment of lateralization of primary aldosteronism by adrenal vein sampling (AVS). Prospective within-patient study in consecutive patients undergoing AVS for primary aldosteronism subtyping. We compared the diagnostic accuracy of baseline and postmetoclopramide lateralization index and relative (to cortisol) aldosterone secretion indices (RASI) for each adrenal gland with aldosterone-producing adenoma (APA) determined by the four corners criteria as the reference diagnosis. We recruited 93 consecutive patients (mean age: 52 years; women 31%). Metoclopramide increased plasma aldosterone in the inferior vena cava and in both adrenal veins. The postmetoclopramide lateralization index was accurate in identifying APA, but did not increase diagnostic accuracy over baseline lateralization index, because the RASI increased similarly in both sides. Conversely, metoclopramide raised RASI to values more than 0.90 bilaterally in non-APA patients allowing accurate identification of factitious aldosterone suppression. In contrast, RASI was 0.90 or less in 48% contralateral to the tumor in APA patients. Regression analysis showed the APA patients with persistent suppression of RASI contralaterally showed a more florid primary aldosteronism phenotype. Metoclopramide does not enhance lateralization of aldosterone excess in APA, but consistently increased the value of RASI in non-APA cases, thus unmasking potentially misleading suppression of aldosterone. Postmetoclopramide RASI may therefore allow a more precise diagnosis when AVS can be achieved only unilaterally.

  5. Fish Oil Supplementation and Fatty Acid Synthase Expression in the Prostate: A Randomized Controlled Trial

    DTIC Science & Technology

    2009-03-01

    AD_________________ Award Number: W81XWH-04-1-0296 TITLE: Fish Oil Supplementation and Fatty Acid...TITLE AND SUBTITLE Fish Oil Supplementation and Fatty Acid Synthase Expression in the Prostate: A 5a. CONTRACT NUMBER...Randomized Controlled Trial 5b. GRANT NUMBER W81XWH-04-1-0296 5c. PROGRAM ELEMENT NUMBER 6 . AUTHOR(S) Jackilen Shannon, Ph.D. 5d. PROJECT NUMBER

  6. Racial differences in sensitivity of blood pressure to aldosterone.

    PubMed

    Tu, Wanzhu; Eckert, George J; Hannon, Tamara S; Liu, Hai; Pratt, Linda M; Wagner, Mary Anne; Dimeglio, Linda A; Jung, Jeesun; Pratt, J Howard

    2014-06-01

    Blacks in comparison with whites are at risk for a more serious form of hypertension with high rates of complications. Greater sodium retention is thought to underlie the blood pressure (BP)-determining physiology of blacks, but specific mechanisms have not been identified. In a prospective observational study of BP, 226 black children and 314 white children (mean age, 10.6 years) were enrolled initially. Assessments were repeated in 85 blacks and 136 whites after reaching adulthood (mean age, 31 years). The relationship of BP to plasma aldosterone concentration in the context of the prevailing level of plasma renin activity was studied in blacks and whites. In a secondary interventional study, 9-α fludrocortisone was administered for 2 weeks to healthy adult blacks and whites to simulate hyperaldosteronism. BP responses in the 2 race groups were then compared. Although black children had lower levels of plasma renin activity and plasma aldosterone, their BP was positively associated with the plasma aldosterone concentration, an effect that increased as plasma renin activity decreased (P=0.004). Data from black adults yielded similar results. No similar relationship was observed in whites. In the interventional study, 9-α fludrocortisone increased BP in blacks but not in whites. In conclusion, aldosterone sensitivity is a significant determinant of BP in young blacks. Although its role in establishing the risk of hypertension is not known, it could be as relevant as the actual level of aldosterone.

  7. Severity of Obstructive Sleep Apnea is Related to Aldosterone Status in Subjects with Resistant Hypertension

    PubMed Central

    Gonzaga, Carolina C.; Gaddam, Krishna K.; Ahmed, Mustafa I.; Pimenta, Eduardo; Thomas, S. Justin; Harding, Susan M.; Oparil, Suzanne; Cofield, Stacey S.; Calhoun, David A.

    2010-01-01

    Background: We previously described a significant correlation between plasma aldosterone concentration (PAC) and severity of obstructive sleep apnea (OSA) in patients with resistant hypertension. This investigation examines the relationship between aldosterone status and OSA in patients with resistant hypertensive—with and without hyperaldosteronism. Methods and Results: One hundred and nine consecutive patients with resistant hypertension were prospectively evaluated with plasma renin activity (PRA), PAC, 24-hour urinary aldosterone excretion (UAldo), and polysomnography. Hyperaldosteronism (PRA < 1 ng·mL-1·h-1 and UAldo ≥ 12 μg/24-h) prevalence was 28% and OSA prevalence was 77%. In patients with hyperaldosteronism, OSA prevalence was 84%, compared with 74% in hypertensive patients with normal aldosterone levels. There were no significant differences in body mass index or neck circumference between aldosterone groups. PAC and UAldo were both significantly correlated with apnea-hypopnea index (AHI) in the high-aldosterone group (ρ = 0.568, p = 0.0009; ρ = 0.533, p = 0.002, respectively). UAldo correlated weakly with apnea-hypopnea index in the normal-aldosterone group, but there was no significant correlation between PAC and AHI in the normal-aldosterone group (ρ = 0.224, p = 0.049; ρ = 0.015, p = 0.898, respectively). Conclusions: Our analysis of patients with resistant hypertension confirms a markedly high prevalence of OSA in this group. Furthermore, severity of OSA was greater in those patients with hyperaldosteronism and related to the degree of aldosterone excess. The correlation between OSA severity and aldosterone supports the hypothesis that aldosterone excess contributes to greater severity of OSA. Citation: Gonzaga CC; Gaddam KK; Ahmed MI; Pimenta E; Thomas SJ; Harding SM; Oparil S; Cofield SS; Calhoun DA. Severity of obstructive sleep apnea is related to aldosterone status in subjects with resistant hypertension. J Clin Sleep Med 2010

  8. Stable expression of lipocalin-type prostaglandin D synthase in cultured preadipocytes impairs adipogenesis program independently of endogenous prostanoids

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hossain, Mohammad Salim; Chowdhury, Abu Asad; Rahman, Mohammad Sharifur

    Lipocalin-type prostaglandin D synthase (L-PGDS) expressed preferentially in adipocytes is responsible for the synthesis of PGD{sub 2} and its non-enzymatic dehydration products, PGJ{sub 2} series, serving as pro-adipogenic factors. However, the role of L-PGDS in the regulation of adipogenesis is complex because of the occurrence of several derivatives from PGD{sub 2} and their distinct receptor subtypes as well as other functions such as a transporter of lipophilic molecules. To manipulate the expression levels of L-PGDS in cultured adipocytes, cultured preadipogenic 3T3-L1 cells were transfected stably with a mammalian expression vector having cDNA encoding murine L-PGDS oriented in the sense direction.more » The isolated cloned stable transfectants with L-PGDS expressed higher levels of the transcript and protein levels of L-PGDS, and synthesized PGD{sub 2} from exogenous arachidonic acid at significantly higher levels. By contrast, the synthesis of PGE{sub 2} remained unchanged, indicating no influence on the reactions of cyclooxygenase (COX) and PGE synthase. Furthermore, the ability of those transfectants to synthesize {Delta}{sup 12}-PGJ{sub 2} increased more greatly during the maturation phase. The sustained expression of L-PGDS in cultured stable transfectants hampered the storage of fats during the maturation phase of adipocytes, which was accompanied by the reduced gene expression of adipocyte-specific markers reflecting the down-regulation of the adipogenesis program. The suppressed adipogenesis was not rescued by either exogenous aspirin or peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) agonists including troglitazone and {Delta}{sup 12}-PGJ{sub 2}. Taken together, the results indicate the negative regulation of the adipogenesis program by the enhanced expression of L-PGDS through a cellular mechanism involving the interference of the PPAR{gamma} signaling pathway without the contribution of endogenous pro-adipogenic prostanoids

  9. Prostacyclin synthase expression and epigenetic regulation in nonsmall cell lung cancer.

    PubMed

    Cathcart, Mary-Clare; Gray, Steven G; Baird, Anne-Marie; Boyle, Elaine; Gately, Kathy; Kay, Elaine; Cummins, Robert; Pidgeon, Graham P; O'Byrne, Kenneth J

    2011-11-15

    Prostacyclin synthase (PGIS) metabolizes prostaglandin H(2), into prostacyclin. This study aimed to determine the expression profile of PGIS in nonsmall cell lung cancer (NSCLC) and examine potential mechanisms involved in PGIS regulation. PGIS expression was examined in human NSCLC and matched controls by reverse transcriptase polymerase chain reaction (RT-PCR), Western analysis, and immunohistochemistry. A 204-patient NSCLC tissue microarray was stained for PGIS and cyclooxygenase 2 (COX2) expression. Staining intensity was correlated with clinical parameters. Epigenetic mechanisms underpinning PGIS promoter expression were examined using RT-PCR, methylation-specific PCR, and chromatin immunoprecipitation analysis. PGIS expression was reduced/absent in human NSCLC protein samples (P < .0001), but not mRNA relative to matched controls. PGIS tissue expression was higher in squamous cell carcinoma (P = .004) and in male patients (P < .05). No significant correlation of PGIS or COX2 expression with overall patient survival was observed, although COX2 was prognostic for short-term (2-year) survival (P < .001). PGIS mRNA expression was regulated by DNA CpG methylation and histone acetylation in NSCLC cell lines, with chromatin remodeling taking place directly at the PGIS gene. PGIS mRNA expression was increased by both demethylation agents and histone deacetylase inhibitors. Protein levels were unaffected by demethylation agents, whereas PGIS protein stability was negatively affected by histone deacetylase inhibitors. PGIS protein expression is reduced in NSCLC, and does not correlate with overall patient survival. PGIS expression is regulated through epigenetic mechanisms. Differences in expression patterns between mRNA and protein levels suggest that PGIS expression and protein stability are regulated post-translationally. PGIS protein stability may have an important therapeutic role in NSCLC. Copyright © 2011 American Cancer Society.

  10. Confirmatory testing in primary aldosteronism: extensive medication switching is not needed in all patients

    PubMed Central

    Solar, Miroslav; Malirova, Eva; Ballon, Marek; Pelouch, Radek; Ceral, Jiri

    2012-01-01

    Objective Confirmatory testing of suspected primary aldosteronism (PA) requires an extensive medication switch that can be difficult for patients with severe complicated hypertension and/or refractory hypokalemia. For this reason, we investigated the effect of chronic antihypertensive medication on confirmatory testing results. To allow the results to be interpreted, the reproducibility of confirmatory testing was also evaluated. Design and methods The study enrolled 114 individuals with suspected PA who underwent two confirmatory tests. The patients were divided into two groups. In Group A, both tests were performed on the guidelines-recommended therapy, i.e. not interfering with the renin–angiotensin–aldosterone system. In Group B, the first test was performed on chronic therapy with the exclusion of thiazides, loop diuretics, and aldosterone antagonists; and the second test was performed on guidelines-recommended therapy. Saline infusion, preceded by oral sodium loading, was used to suppress aldosterone secretion. Results Agreement in the interpretation of the two confirmatory tests was observed in 84 and 66% of patients in Groups A and B respectively. For all 20 individuals in Group A who ever had end-test serum aldosterone levels ≥240 pmol/l, aldosterone was concordantly nonsuppressible during the other test. Similarly, for all 16 individuals in Group B who had end-test serum aldosterone levels ≥240 pmol/l on modified chronic therapy, aldosterone remained nonsuppressible with guidelines-recommended therapy. Conclusion Confirmatory testing performed while the patient is on chronic therapy without diuretics and aldosterone antagonists can confirm the diagnosis of PA, provided serum aldosterone remains markedly elevated at the end of saline infusion. PMID:22253400

  11. The effects of 19-nor-aldosterone on blood pressure of adrenalectomized spontaneously hypertensive rats.

    PubMed

    Morris, D J; Gorsline, J; Tresco, P A; Harnik, M

    1985-12-01

    The relative hypertensinogenic potencies of recently synthesized 19-nor-aldosterone and its precursor 19-OH-aldosterone were assessed in comparison to that of aldosterone (Aldo) in young (6-week-old) adrenalectomized (ADX) spontaneously hypertensive rats (SHR). Infusion of 19-nor-aldosterone for 2 weeks by Alza mini-osmotic pumps caused significant, dose-dependent increases in the systolic blood pressure (BP) of young ADX SHR; dosages of 0.1 and 0.5 microgram/day raised the BP from 127 +/- 2 mmHg to 164 +/- 9 and 180 +/- 11 mmHg, respectively. During this period, control ADX SHR receiving vehicle only remained normotensive. Similar increases in BP were seen only with infusion of slightly higher dosages of Aldo (0.5 and 1.0 micrograms/day). In contrast, 19-OH-aldosterone infused at higher dosages (10 or 25 micrograms/day) caused little change in BP of ADX SHR. Full suppression of plasma renin activity (PRA) was observed with 0.1 and 0.5 microgram/day 19-nor-aldosterone, whereas Aldo caused similar decreases in PRA only at dosages of 0.5 microgram/day and higher. Interestingly, although infusions of 19-OH-aldosterone did not cause a significant change in BP, these dosages (10 and 25 micrograms/day) significantly suppressed PRA. These studies which show that 19-nor-aldosterone is equipotent to Aldo, and perhaps slightly more active in ADX SHR, indicate that 19-nor-aldosterone is a potentially important hypertensinogenic steroid.

  12. Geranyl diphosphate synthase large subunit, and methods of use

    DOEpatents

    Croteau, Rodney B.; Burke, Charles C.; Wildung, Mark R.

    2001-10-16

    A cDNA encoding geranyl diphosphate synthase large subunit from peppermint has been isolated and sequenced, and the corresponding amino acid sequence has been determined. Replicable recombinant cloning vehicles are provided which code for geranyl diphosphate synthase large subunit). In another aspect, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding geranyl diphosphate synthase large subunit. In yet another aspect, the present invention provides isolated, recombinant geranyl diphosphate synthase protein comprising an isolated, recombinant geranyl diphosphate synthase large subunit protein and an isolated, recombinant geranyl diphosphate synthase small subunit protein. Thus, systems and methods are provided for the recombinant expression of geranyl diphosphate synthase.

  13. Natriuretic Peptide Receptor Guanylyl Cyclase-A Protects Podocytes from Aldosterone-Induced Glomerular Injury

    PubMed Central

    Ogawa, Yoshihisa; Yokoi, Hideki; Kasahara, Masato; Mori, Kiyoshi; Kato, Yukiko; Kuwabara, Takashige; Imamaki, Hirotaka; Kawanishi, Tomoko; Koga, Kenichi; Ishii, Akira; Tokudome, Takeshi; Kishimoto, Ichiro; Sugawara, Akira; Nakao, Kazuwa

    2012-01-01

    Natriuretic peptides produced by the heart in response to cardiac overload exert cardioprotective and renoprotective effects by eliciting natriuresis, reducing BP, and inhibiting cell proliferation and fibrosis. These peptides also antagonize the renin-angiotensin-aldosterone system, but whether this mechanism contributes to their renoprotective effect is unknown. Here, we examined the kidneys of mice lacking the guanylyl cyclase-A (GC-A) receptor for natriuretic peptides under conditions of high aldosterone and high dietary salt. After 4 weeks of administering aldosterone and a high-salt diet, GC-A knockout mice, but not wild-type mice, exhibited accelerated hypertension with massive proteinuria. Aldosterone-infused GC-A knockout mice had marked mesangial expansion, segmental sclerosis, severe podocyte injury, and increased oxidative stress. Reducing the BP with hydralazine failed to lessen such changes; in contrast, blockade of the renin-angiotensin-aldosterone system markedly reduced albuminuria, ameliorated podocyte injury, and reduced oxidative stress. Furthermore, treatment with the antioxidant tempol significantly reduced albuminuria and abrogated the histologic changes. In cultured podocytes, natriuretic peptides inhibited aldosterone-induced mitogen-activated protein kinase phosphorylation. Taken together, these results suggest that renoprotective properties of the endogenous natriuretic peptide/GC-A system may result from the local inhibition of the renin-angiotensin-aldosterone system and oxidative stress in podocytes. PMID:22652704

  14. Aldosterone does not require angiotensin II to activate NCC through a WNK4-SPAK-dependent pathway.

    PubMed

    van der Lubbe, Nils; Lim, Christina H; Meima, Marcel E; van Veghel, Richard; Rosenbaek, Lena Lindtoft; Mutig, Kerim; Danser, Alexander H J; Fenton, Robert A; Zietse, Robert; Hoorn, Ewout J

    2012-06-01

    We and others have recently shown that angiotensin II can activate the sodium chloride cotransporter (NCC) through a WNK4-SPAK-dependent pathway. Because WNK4 was previously shown to be a negative regulator of NCC, it has been postulated that angiotensin II converts WNK4 to a positive regulator. Here, we ask whether aldosterone requires angiotensin II to activate NCC and if their effects are additive. To do so, we infused vehicle or aldosterone in adrenalectomized rats that also received the angiotensin receptor blocker losartan. In the presence of losartan, aldosterone was still capable of increasing total and phosphorylated NCC twofold to threefold. The kinases WNK4 and SPAK also increased with aldosterone and losartan. A dose-dependent relationship between aldosterone and NCC, SPAK, and WNK4 was identified, suggesting that these are aldosterone-sensitive proteins. As more functional evidence of increased NCC activity, we showed that rats receiving aldosterone and losartan had a significantly greater natriuretic response to hydrochlorothiazide than rats receiving losartan only. To study whether angiotensin II could have an additive effect, rats receiving aldosterone with losartan were compared with rats receiving aldosterone only. Rats receiving aldosterone only retained more sodium and had twofold to fourfold increase in phosphorylated NCC. Together, our results demonstrate that aldosterone does not require angiotensin II to activate NCC and that WNK4 appears to act as a positive regulator in this pathway. The additive effect of angiotensin II may favor electroneutral sodium reabsorption during hypovolemia and may contribute to hypertension in diseases with an activated renin-angiotensin-aldosterone system.

  15. NEFM (Neurofilament Medium) Polypeptide, a Marker for Zona Glomerulosa Cells in Human Adrenal, Inhibits D1R (Dopamine D1 Receptor)-Mediated Secretion of Aldosterone.

    PubMed

    Maniero, Carmela; Garg, Sumedha; Zhao, Wanfeng; Johnson, Timothy Isaac; Zhou, Junhua; Gurnell, Mark; Brown, Morris J

    2017-08-01

    Heterogeneity among aldosterone-producing adenomas (APAs) has been highlighted by the discovery of somatic mutations. KCNJ5 mutations predominate in large zona fasciculata (ZF)-like APAs; mutations in CACNA1D , ATP1A1, ATP2B3 , and CTNNB1 are more likely to be found in small zona glomerulosa (ZG)-like APAs. Microarray comparison of KCNJ5 mutant versus wild-type APAs revealed significant differences in transcriptomes. NEFM , encoding a neurofilament subunit which is a D1R (dopamine D1 receptor)-interacting protein, was 4-fold upregulated in ZG-like versus ZF-like APAs and 14-fold more highly expressed in normal ZG versus ZF. Immunohistochemistry confirmed selective expression of NEFM (neurofilament medium) polypeptide in ZG and in ZG-like APAs. Silencing NEFM in adrenocortical H295R cells increased basal aldosterone secretion and cell proliferation; silencing also amplified aldosterone stimulation by the D1R agonist, fenoldopam, and inhibition by the D1R antagonist, SCH23390. NEFM coimmunoprecipitated with D1R, and its expression was stimulated by fenoldopam. Immunohistochemistry for D1R was mainly intracellular in ZG-like APAs but membranous in ZF-like APAs. Aldosterone secretion in response to fenoldopam in primary cells from ZF-like APAs was higher than in cells from ZG-like APAs. Transfection of mutant KCNJ5 caused a large reduction in NEFM expression in H295R cells. We conclude that NEFM is a negative regulator of aldosterone production and cell proliferation, in part by facilitating D1R internalization from the plasma membrane. Downregulation of NEFM in ZF-like APAs may contribute to a D1R/D2R imbalance underlying variable pharmacological responses to dopaminergic drugs among patients with APAs. Finally, taken together, our data point to the possibility that ZF-like APAs are in fact ZG in origin. © 2017 American Heart Association, Inc.

  16. Genomic and rapid effects of aldosterone: what we know and do not know thus far.

    PubMed

    Hermidorff, Milla Marques; de Assis, Leonardo Vinícius Monteiro; Isoldi, Mauro César

    2017-01-01

    Aldosterone is the most known mineralocorticoid hormone synthesized by the adrenal cortex. The genomic pathway displayed by aldosterone is attributed to the mineralocorticoid receptor (MR) signaling. Even though the rapid effects displayed by aldosterone are long known, our knowledge regarding the receptor responsible for such event is still poor. It is intense that the debate whether the MR or another receptor-the "unknown receptor"-is the receptor responsible for the rapid effects of aldosterone. Recently, G protein-coupled estrogen receptor-1 (GPER-1) was elegantly shown to mediate some aldosterone-induced rapid effects in several tissues, a fact that strongly places GPER-1 as the unknown receptor. It has also been suggested that angiotensin receptor type 1 (AT1) also participates in the aldosterone-induced rapid effects. Despite this open question, the relevance of the beneficial effects of aldosterone is clear in the kidneys, colon, and CNS as aldosterone controls the important water reabsorption process; on the other hand, detrimental effects displayed by aldosterone have been reported in the cardiovascular system and in the kidneys. In this line, the MR antagonists are well-known drugs that display beneficial effects in patients with heart failure and hypertension; it has been proposed that MR antagonists could also play an important role in vascular disease, obesity, obesity-related hypertension, and metabolic syndrome. Taken altogether, our goal here was to (1) bring a historical perspective of both genomic and rapid effects of aldosterone in several tissues, and the receptors and signaling pathways involved in such processes; and (2) critically address the controversial points within the literature as regarding which receptor participates in the rapid pathway display by aldosterone.

  17. Synthesis of 19-nor-aldosterone, 18-hydroxy-19-nor-corticosterone and 18,19-dihydroxycorticosterone in the human aldosterone-producing adenoma.

    PubMed

    Takeda, Y; Lewicka, S; Koch, S; Bige, K; Vecsei, P; Abdelhamid, S; Cojocaru, M; Harnik, M

    1990-11-30

    The recently synthesized 18-C-steroid derivative, 19-nor-aldosterone(19-nor- aldo) and 18-hydroxy-19-nor-corticosterone(18-OH-19-nor-corticosterone) possess mineralocoroticoid and hypertensinogenic activity. They and an additional newly synthesized steriod, 18,19-dihydroxycorticosterone[18,19(OH)2-corticosterone], may play a role in the etiology and pathogenesis of disorders thought to be caused by steroids with mineralocorticoid and hypertensionogenic properties. In this study we provide evidence that 19-nor-aldo, 18-OH-19-nor-corticosterone and 18,19(OH)2-corticosterone are produced in vitro by aldosterone-producing adrenal adenomas and adenomas and adenoma of Cushing's syndrome. "silent" adrenal adenomas and the adjacent adrenal tissue. Measurable amounts of these steroids were found in the incubation fluids of adrenal tissues using specific RIAs performed after a sequence of HPLC systems. The rates of production of the three steroids were high in the aldosterone-producing adrenal adenomas and in adrenal hyperplasia compared with in either Cushing's adenoma or "silent" adenoma.

  18. Liver X receptor alpha regulates fatty acid synthase expression in chicken.

    PubMed

    Demeure, O; Duby, C; Desert, C; Assaf, S; Hazard, D; Guillou, H; Lagarrigue, S

    2009-12-01

    Liver X receptor alpha (LXRalpha), also referred to as nuclear receptor subfamily 1, group H, member 3 is a member of the nuclear hormone receptor superfamily, and has recently been shown to act as a master transcription factor governing hepatic lipogenesis in mammals. Liver X receptor alpha directly regulates both the expression of other lipogenic transcription factors and the expression of lipogenic enzymes, thereby enhancing hepatic fatty acid synthesis (FASN). In birds, like in humans, fatty acid synthesis primarily occurs in the liver. Whether LXRalpha is involved in hepatic regulation of lipogenic genes remained to be investigated in this species. Here we show that fatty acid synthase and the expression of other lipogenic genes (sterol regulatory element binding protein 1 and steroyl coenzyme A desaturase 1) are induced in chicken hepatoma cells in response to a pharmacological liver X receptor agonist, T0901317. A detailed analysis of the chicken FASN promoter revealed a functional liver X response element. These data define the chicken FASN gene as a direct target of LXRalpha and further expand the role of LXRalpha as a regulator of lipid metabolism in this species.

  19. Primary aldosteronism: results of adrenalectomy for nonsingle adenoma.

    PubMed

    Quillo, Amy R; Grant, Clive S; Thompson, Geoffrey B; Farley, David R; Richards, Melanie L; Young, William F

    2011-07-01

    Historically, treatment of confirmed primary aldosteronism has been adrenalectomy for unilateral adenoma; bilateral hypersecretion is treated medically. Increasingly, we use adrenal venous sampling (AVS) to define unilateral hypersecretion. Histology of glands resected based on AVS often reveals multiple nodules or hyperplasia. The aim of this study was to compare patients with multiple nodules or hyperplasia with those with single adenoma with regard to cure, preoperative imaging, AVS ratio, and biochemical evaluation to determine if a nonsingle adenoma (NSA) process could be predicted to impact extent of adrenalectomy. This was a retrospective study reviewing a single-institutional surgical experience at a tertiary academic center from 1993 to 2008, during which 215 patients with primary aldosteronism underwent unilateral adrenalectomy based on imaging of a single adenoma (normal contralateral gland) or AVS ratios. Histology included single adenoma versus NSA; cure was defined as normal immediate postoperative plasma or urine aldosterone level, normal aldosterone:renin ratio, or normotension without antihypertensive medications. Follow-up (mean 13 months, range 0 to 185 months) was available for 167 patients: 132 (79%) single adenoma and 35 (21%) NSA. All 35 patients with NSA and 128 patients (97%) with single adenoma were cured. Imaging studies correctly predicted NSA in 29% and 57% when combined with AVS. Identifying patients with NSA preoperatively was impossible biochemically: mean serum and urinary aldosterone levels and AVS ratios were not different than those of the single adenoma group. Twenty-one percent of patients had NSA, all cured by unilateral adrenalectomy. No preoperative evaluation reliably predicted NSA. Therefore, total unilateral adrenalectomy was safest given the potential for incomplete resection with partial adrenalectomy. Accurate AVS is highly predictive of cure irrespective of the unilateral adrenal histology. Copyright © 2011 American

  20. Characterization of resistant hypertension: association between resistant hypertension, aldosterone, and persistent intravascular volume expansion.

    PubMed

    Gaddam, Krishna K; Nishizaka, Mari K; Pratt-Ubunama, Monique N; Pimenta, Eduardo; Aban, Inmaculada; Oparil, Suzanne; Calhoun, David A

    2008-06-09

    Resistant hypertension is a common clinical problem and greatly increases the risk of target organ damage. We evaluated the characteristics of 279 consecutive patients with resistant hypertension (uncontrolled despite the use of 3 antihypertensive agents) and 53 control subjects (with normotension or hypertension controlled by using aldosterone concentration, plasma renin activity, aldosterone to renin ratio, brain-type natriuretic peptide, atrial natriuretic peptide, and 24-hour urinary aldosterone (UAldo), cortisol, sodium, and potassium values while adhering to a routine diet. Plasma aldosterone (P < .001), aldosterone to renin ratio (P < .001), 24-hour UAldo (P = .02), brain-type natriuretic peptide (P = .007), and atrial natriuretic peptide (P = .001) values were higher and plasma renin activity (P = .02) and serum potassium (P < .001) values were lower in patients with resistant hypertension vs controls. Of patients with resistant hypertension, men had significantly higher plasma aldosterone (P = .003), aldosterone to renin ratio (P = .02), 24-hour UAldo (P < .001), and urinary cortisol (P < .001) values than women. In univariate linear regression analysis, body mass index (P = .01), serum potassium (P < .001), urinary cortisol (P < .001), urinary sodium (P = .02), and urinary potassium (P < .001) values were correlated with 24-hour UAldo levels. Serum potassium (P = .001), urinary potassium (P < .001), and urinary sodium (P = .03) levels were predictors of 24-hour UAldo levels in multivariate modeling. Aldosterone levels are higher and there is evidence of intravascular volume expansion (higher brain-type and atrial natriuretic peptide levels) in patients with resistant hypertension vs controls. These differences are most pronounced in men. A significant correlation between 24-hour urinary aldosterone levels and cortisol excretion suggests that a common stimulus, such as

  1. [How to screen for pheochromocytoma, primary aldosteronism and Cushing's syndrome].

    PubMed

    Meyer, Patrick

    2009-01-07

    Pheochromocytoma, primary aldosteronism and Cushing's syndrome are uncommon disorders and are difficult to diagnose because laboratory tests lack validation and specificity. Despite these limitations, practice guidelines are proposed to standardize the screening procedure. The most reliable method to diagnose pheochromocytoma is the measurement of plasmatic and/or urinary metanephrines and normetanephrines depending on the pre-test probability of the disease. The approach for detection of primary aldosteronism is based on the aldosterone-renin ratio under standard conditions. Finally, three tests are available to establish the diagnosis of Cushing's syndrome: 24-h urinary free cortisol excretion, low-dose dexamethasone suppression test and the recent and promising late evening salivary cortisol.

  2. Sensitivity of Aspergillus nidulans to the Cellulose Synthase Inhibitor Dichlobenil: Insights from Wall-Related Genes’ Expression and Ultrastructural Hyphal Morphologies

    PubMed Central

    Obersriebnig, Michael; Salerno, Marco; Pum, Dietmar; Strauss, Joseph

    2013-01-01

    The fungal cell wall constitutes an important target for the development of antifungal drugs, because of its central role in morphogenesis, development and determination of fungal-specific molecular features. Fungal walls are characterized by a network of interconnected glycoproteins and polysaccharides, namely α-, β-glucans and chitin. Cell walls promptly and dynamically respond to environmental stimuli by a signaling mechanism, which triggers, among other responses, modulations in wall biosynthetic genes’ expression. Despite the absence of cellulose in the wall of the model filamentous fungus Aspergillus nidulans, we found in this study that fungal growth, spore germination and morphology are affected by the addition of the cellulose synthase inhibitor dichlobenil. Expression analysis of selected genes putatively involved in cell wall biosynthesis, carried out at different time points of drug exposure (i.e. 0, 1, 3, 6 and 24 h), revealed increased expression for the putative mixed linkage β-1,3;1,4 glucan synthase celA together with the β-1,3-glucan synthase fksA and the Rho-related GTPase rhoA. We also compared these data with the response to Congo Red, a known plant/fungal drug affecting both chitin and cellulose biosynthesis. The two drugs exerted different effects at the cell wall level, as shown by gene expression analysis and the ultrastructural features observed through atomic force microscopy and scanning electron microscopy. Although the concentration of dichlobenil required to affect growth of A. nidulans is approximately 10-fold higher than that required to inhibit plant cellulose biosynthesis, our work for the first time demonstrates that a cellulose biosynthesis inhibitor affects fungal growth, changes fungal morphology and expression of genes connected to fungal cell wall biosynthesis. PMID:24312197

  3. The prevalence of CTNNB1 mutations in primary aldosteronism and consequences for clinical outcomes.

    PubMed

    Wu, Vin-Cent; Wang, Shuo-Meng; Chueh, Shih-Chieh Jeff; Yang, Shao-Yu; Huang, Kuo-How; Lin, Yen-Hung; Wang, Jian-Jhong; Connolly, Rory; Hu, Ya-Hui; Gomez-Sanchez, Celso E; Peng, Kang-Yung; Wu, Kwan-Dun

    2017-01-19

    Constitutive activation of the Wnt pathway/β-catenin signaling may be important in aldosterone-producing adenoma (APA). However, significant gaps remain in our understanding of the prevalence and clinical outcomes after adrenalectomy in APA patients harboring CTNNB1 mutations. The molecular expression of CYP11B2 and gonadal receptors in adenomas were also explored. Adenomas from 219 APA patients (95 men; 44.2%; aged 50.5 ± 11.9 years) showed a high rate of somatic mutations (n = 128, 58.4%). The majority of them harbored KCNJ5 mutations (n = 116, 52.9%); 8 patients (3.7%, 6 women) had CTNNB1 mutations. Patients with APAs harboring CTNNB1 mutations were older and had shorter duration of hypertension. After adrenalectomy, CTNNB1 mutation carriers had a higher possibility (87.5%) of residual hypertension than other APA patients. APAs harboring CTNNB1 mutations have heterogeneous staining of β-catenin and variable expression of gonadal receptors and both CYP11B1 and CYP11B2. This suggests that CTNNB1 mutations may be more related to tumorigenesis rather than excessive aldosterone production.

  4. Angiotensin II type 1 receptor autoantibody as a novel regulator of aldosterone independent of preeclampsia.

    PubMed

    Yang, Jie; Li, Li; Shang, Jian-Yu; Cai, Lin; Song, Li; Zhang, Su-Li; Li, Hao; Li, Xiao; Lau, Wayne Bond; Ma, Xin-Liang; Liu, Hui-Rong

    2015-05-01

    Preeclamptic women and their infants have significant morbidity and mortality worldwide. Abnormal aldosterone signaling is involved in the pathogenesis of preeclampsia, and the presence of agonistic autoantibodies against the angiotensin II type 1 receptor (AT1-AA) during disease has been observed. The role of AT1-AA in aldosterone generation with or without disease and the long-term impact of AT1-AA circulation in blood remain unclear. We therefore assessed circulating AT1-AA and aldosterone levels in 76 patients with preeclampsia (35 severe and 41 mild), 26 patients with gestational hypertension, and 50 normotensive healthy pregnant women. First, the correlation of AT1-AA levels was confirmed for preeclamptic patients. We report here that all AT1-AA-positive hypertensive pregnant women exhibited decreased aldosterone levels, and early-onset preeclampsia patients with high proteinuria showed an inverse correlation of aldosterone levels with AT1-AA. To study this effect in more detail, we confirmed that AT1-AA decreased aldosterone levels in pregnant rats and then demonstrated that aldosterone levels decreased in response to the chronic administration of AT1-AA into nonpregnant rats. These results suggested that AT1-AA regulates levels of aldosterone, which was tested with cell culture studies, revealing that activation of AT1 receptors by AT1-AA directly led to abnormal aldosterone generation in a time and dose-dependent manner. We present here a mechanism for regulation of aldosterone production: AT1-AA activates AT1 receptors on adrenocortical cells independent of pregnancy, in a time and dose-dependent manner.

  5. Evaluation of Vasopressin for Septic Shock in Patients on Chronic Renin-Angiotensin-Aldosterone System Inhibitors.

    PubMed

    Erwin, Beth L; Denaburg, Michael A; Barker, Andrew B; McArdle, Philip J; Windham, Samuel T; Morgan, Charity J

    2017-12-01

    To compare the hemodynamic response in septic shock patients receiving vasopressin who were on chronic renin-angiotensin-aldosterone system inhibitor therapy with those who were not. Single-center, retrospective cohort study. Medical and surgical ICUs at a 1,100-bed academic medical center. Medical and surgical ICU patients with septic shock who received vasopressin infusion added to at least one concomitant vasopressor agent between January 2014 and December 2015, then divided into two cohorts: 1) patients who were on chronic renin-angiotensin-aldosterone system inhibitor therapy as outpatients and 2) patients who were not on chronic renin-angiotensin-aldosterone system inhibitor therapy as outpatients. None. Mean arterial pressure at 6 hours was 72.2 mm Hg in the renin-angiotensin-aldosterone system inhibitor group versus 69.7 mm Hg in the non-renin-angiotensin-aldosterone system inhibitor group (p = 0.298). There was no difference in mean arterial pressure at 1, 24, or 48 hours between groups. Total concomitant vasopressor requirements, based on norepinephrine equivalents excluding vasopressin, were significantly lower at 24 hours in the renin-angiotensin-aldosterone system inhibitor group versus the non-renin-angiotensin-aldosterone system inhibitor group (10.7 vs 18.1 µg/min, respectively; p = 0.007), but no significant differences were seen at the other time points assessed. There were no significant differences in ICU or hospital length of stay or mortality. There was no significant difference in the primary outcome of 6-hour mean arterial pressure in septic shock patients receiving vasopressin who were on chronic renin-angiotensin-aldosterone system inhibitor therapy versus those receiving vasopressin who were not on chronic renin-angiotensin-aldosterone system inhibitor therapy. Renin-angiotensin-aldosterone system inhibitor patients had lower total concomitant vasopressor requirements at 24 hours compared with non-renin-angiotensin-aldosterone system

  6. Renin-Angiotensin-Aldosterone Genotype Influences Ventricular Remodeling in Infants with Single Ventricle

    PubMed Central

    Mital, Seema; Chung, Wendy K.; Colan, Steven D.; Sleeper, Lynn A.; Manlhiot, Cedric; Arrington, Cammon B.; Cnota, James F.; Graham, Eric M.; Mitchell, Michael E.; Goldmuntz, Elizabeth; Li, Jennifer S.; Levine, Jami C.; Lee, Teresa M.; Margossian, Renee; Hsu, Daphne T.

    2011-01-01

    Background We investigated the effect of polymorphisms in the renin-angiotensin-aldosterone system (RAAS) genes on ventricular remodeling, growth, renal function and response to enalapril in infants with single ventricle. Methods and Results Single ventricle infants enrolled in a randomized trial of enalapril were genotyped for polymorphisms in 5 genes: angiotensinogen, angiotensin-converting enzyme, angiotensin II type 1 receptor, aldosterone synthase, and chymase. Alleles associated with RAAS upregulation were classified as risk alleles. Ventricular mass, volume, somatic growth, renal function using estimated glomerular filtration rate (eGFR), and response to enalapril were compared between patients with ≥2 homozygous risk genotypes (high-risk), and those with <2 homozygous risk genotypes (low-risk) at two time points - before the superior-cavopulmonary-connection (pre-SCPC) and at age 14 months. Of 230 trial subjects, 154 were genotyped: 38 were high-risk, 116 were low-risk. Ventricular mass and volume were elevated in both groups pre-SCPC. Ventricular mass and volume decreased and eGFR increased after SCPC in the low-risk (p<0.05) but not the high-risk group. These responses were independent of enalapril treatment. Weight and height z-scores were lower at baseline and height remained lower in the high-risk group at 14 months especially in those receiving enalapril (p<0.05). Conclusions RAAS-upregulation genotypes were associated with failure of reverse remodeling after SCPC surgery, less improvement in renal function, and impaired somatic growth, the latter especially in patients receiving enalapril. RAAS genotype may identify a high-risk subgroup of single ventricle patients who fail to fully benefit from volume unloading surgery. Follow-up is warranted to assess longterm impact. Clinical Trial Registration Clinical Trials.gov Identifier NCT00113087 PMID:21576655

  7. Regulation of human nitric oxide synthase 2 expression by Wnt beta-catenin signaling.

    PubMed

    Du, Qiang; Park, Kyung Soo; Guo, Zhong; He, Peijun; Nagashima, Makoto; Shao, Lifang; Sahai, Rohit; Geller, David A; Hussain, S Perwez

    2006-07-15

    Nitric oxide (NO.), an important mediator of inflammation, and beta-catenin, a component of the Wnt-adenomatous polyposis coli signaling pathway, contribute to the development of cancer. We have identified two T-cell factor 4 (Tcf-4)-binding elements (TBE1 and TBE2) in the promoter of human inducible NO synthase 2 (NOS2). We tested the hypothesis that beta-catenin regulates human NOS2 gene. Mutation in either of the two TBE sites decreased the basal and cytokine-induced NOS2 promoter activity in different cell lines. The promoter activity was significantly reduced when both TBE1 and TBE2 sites were mutated (P < 0.01). Nuclear extract from HCT116, HepG2, or DLD1 cells bound to NOS2 TBE1 or TBE2 oligonucleotides in electrophoretic mobility shift assays and the specific protein-DNA complexes were supershifted with anti-beta-catenin or anti-Tcf-4 antibody. Overexpression of beta-catenin and Tcf-4 significantly increased both basal and cytokine-induced NOS2 promoter activity (P < 0.01), and the induction was dependent on intact TBE sites. Overexpression of beta-catenin or Tcf-4 increased NOS2 mRNA and protein expression in HCT116 cells. Lithium chloride (LiCl), an inhibitor of glycogen synthase kinase-3beta, increased cytosolic and nuclear beta-catenin level, NOS2 expression, and NO. production in primary human and rat hepatocytes and cancer cell lines. Treatment with Wnt-3A-conditioned medium increased beta-catenin and NOS2 expression in fetal human hepatocytes. When administered in vivo, LiCl increased hepatic beta-catenin level in a dose-dependent manner with simultaneous increase in NOS2 expression. These data are consistent with the hypothesis that beta-catenin up-regulates NOS2 and suggest a novel mechanism by which the Wnt/beta-catenin signaling pathway may contribute to cancer by increasing NO. production.

  8. Familial Analysis of Epistatic and Sex-Dependent Association of Genes of the Renin-Angiotensin-Aldosterone System and Blood Pressure.

    PubMed

    Scurrah, Katrina J; Lamantia, Angela; Ellis, Justine A; Harrap, Stephen B

    2017-06-01

    Renin-angiotensin-aldosterone system genes have been inconsistently associated with blood pressure, possibly because of unrecognized influences of sex-dependent genetic effects or gene-gene interactions (epistasis). We tested association of systolic blood pressure with single-nucleotide polymorphisms (SNPs) at renin ( REN ), angiotensinogen ( AGT ), angiotensin-converting enzyme ( ACE ), angiotensin II type 1 receptor ( AGTR1 ), and aldosterone synthase ( CYP11B2 ), including sex-SNP or SNP-SNP interactions. Eighty-eight tagSNPs were tested in 2872 white individuals in 809 pedigrees from the Victorian Family Heart Study using variance components models. Three SNPs (rs8075924 and rs4277404 at ACE and rs12721297 at AGTR1 ) were individually associated with lower systolic blood pressure with significant ( P <0.00076) effect sizes ≈1.7 to 2.5 mm Hg. Sex-specific associations were seen for 3 SNPs in men (rs2468523 and rs2478544 at AGT and rs11658531 at ACE ) and 1 SNP in women (rs12451328 at ACE ). SNP-SNP interaction was suggested ( P <0.005) for 14 SNP pairs, none of which had shown individual association with systolic blood pressure. Four SNP pairs were at the same gene (2 for REN , 1 for AGT , and 1 for AGTR1 ). The SNP rs3097 at CYP11B2 was represented in 5 separate pairs. SNPs at key renin-angiotensin-aldosterone system genes associate with systolic blood pressure individually in both sexes, individually in one sex only and only when combined with another SNP. Analyses that incorporate sex-dependent and epistatic effects could reconcile past inconsistencies and account for some of the missing heritability of blood pressure and are generally relevant to SNP association studies for any phenotype. © 2017 American Heart Association, Inc.

  9. Transient Receptor Potential Canonical (TRPC)/Orai1-dependent Store-operated Ca2+ Channels: NEW TARGETS OF ALDOSTERONE IN CARDIOMYOCYTES.

    PubMed

    Sabourin, Jessica; Bartoli, Fiona; Antigny, Fabrice; Gomez, Ana Maria; Benitah, Jean-Pierre

    2016-06-17

    Store-operated Ca(2+) entry (SOCE) has emerged as an important mechanism in cardiac pathology. However, the signals that up-regulate SOCE in the heart remain unexplored. Clinical trials have emphasized the beneficial role of mineralocorticoid receptor (MR) signaling blockade in heart failure and associated arrhythmias. Accumulated evidence suggests that the mineralocorticoid hormone aldosterone, through activation of its receptor, MR, might be a key regulator of Ca(2+) influx in cardiomyocytes. We thus assessed whether and how SOCE involving transient receptor potential canonical (TRPC) and Orai1 channels are regulated by aldosterone/MR in neonatal rat ventricular cardiomyocytes. Molecular screening using qRT-PCR and Western blotting demonstrated that aldosterone treatment for 24 h specifically increased the mRNA and/or protein levels of Orai1, TRPC1, -C4, -C5, and stromal interaction molecule 1 through MR activation. These effects were correlated with a specific enhancement of SOCE activities sensitive to store-operated channel inhibitors (SKF-96365 and BTP2) and to a potent Orai1 blocker (S66) and were prevented by TRPC1, -C4, and Orai1 dominant negative mutants or TRPC5 siRNA. A mechanistic approach showed that up-regulation of serum- and glucocorticoid-regulated kinase 1 mRNA expression by aldosterone is involved in enhanced SOCE. Functionally, 24-h aldosterone-enhanced SOCE is associated with increased diastolic [Ca(2+)]i, which is blunted by store-operated channel inhibitors. Our study provides the first evidence that aldosterone promotes TRPC1-, -C4-, -C5-, and Orai1-mediated SOCE in cardiomyocytes through an MR and serum- and glucocorticoid-regulated kinase 1 pathway. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Renin-angiotensin-aldosterone system inhibitors improve membrane stability and change gene-expression profiles in dystrophic skeletal muscles.

    PubMed

    Chadwick, Jessica A; Bhattacharya, Sayak; Lowe, Jeovanna; Weisleder, Noah; Rafael-Fortney, Jill A

    2017-02-01

    Angiotensin-converting enzyme inhibitors (ACEi) and mineralocorticoid receptor (MR) antagonists are FDA-approved drugs that inhibit the renin-angiotensin-aldosterone system (RAAS) and are used to treat heart failure. Combined treatment with the ACEi lisinopril and the nonspecific MR antagonist spironolactone surprisingly improves skeletal muscle, in addition to heart function and pathology in a Duchenne muscular dystrophy (DMD) mouse model. We recently demonstrated that MR is present in all limb and respiratory muscles and functions as a steroid hormone receptor in differentiated normal human skeletal muscle fibers. The goals of the current study were to begin to define cellular and molecular mechanisms mediating the skeletal muscle efficacy of RAAS inhibitor treatment. We also compared molecular changes resulting from RAAS inhibition with those resulting from the current DMD standard-of-care glucocorticoid treatment. Direct assessment of muscle membrane integrity demonstrated improvement in dystrophic mice treated with lisinopril and spironolactone compared with untreated mice. Short-term treatments of dystrophic mice with specific and nonspecific MR antagonists combined with lisinopril led to overlapping gene-expression profiles with beneficial regulation of metabolic processes and decreased inflammatory gene expression. Glucocorticoids increased apoptotic, proteolytic, and chemokine gene expression that was not changed by RAAS inhibitors in dystrophic mice. Microarray data identified potential genes that may underlie RAAS inhibitor treatment efficacy and the side effects of glucocorticoids. Direct effects of RAAS inhibitors on membrane integrity also contribute to improved pathology of dystrophic muscles. Together, these data will inform clinical development of MR antagonists for treating skeletal muscles in DMD. Copyright © 2017 the American Physiological Society.

  11. Expression Patterns, Activities and Carbohydrate-Metabolizing Regulation of Sucrose Phosphate Synthase, Sucrose Synthase and Neutral Invertase in Pineapple Fruit during Development and Ripening

    PubMed Central

    Zhang, Xiu-Mei; Wang, Wei; Du, Li-Qing; Xie, Jiang-Hui; Yao, Yan-Li; Sun, Guang-Ming

    2012-01-01

    Differences in carbohydrate contents and metabolizing-enzyme activities were monitored in apical, medial, basal and core sections of pineapple (Ananas comosus cv. Comte de paris) during fruit development and ripening. Fructose and glucose of various sections in nearly equal amounts were the predominant sugars in the fruitlets, and had obvious differences until the fruit matured. The large rise of sucrose/hexose was accompanied by dramatic changes in sucrose phosphate synthase (SPS) and sucrose synthase (SuSy) activities. By contrast, neutral invertase (NI) activity may provide a mechanism to increase fruit sink strength by increasing hexose concentrations. Furthermore, two cDNAs of Ac-sps (accession no. GQ996582) and Ac-ni (accession no. GQ996581) were first isolated from pineapple fruits utilizing conserved amino-acid sequences. Homology alignment reveals that the amino acid sequences contain some conserved function domains. Transcription expression analysis of Ac-sps, Ac-susy and Ac-ni also indicated distinct patterns related to sugar accumulation and composition of pineapple fruits. It suggests that differential expressions of multiple gene families are necessary for sugar metabolism in various parts and developmental stages of pineapple fruit. A cycle of sucrose breakdown in the cytosol of sink tissues could be mediated through both Ac-SuSy and Ac-NI, and Ac-NI could be involved in regulating crucial steps by generating sugar signals to the cells in a temporally and spatially restricted fashion. PMID:22949808

  12. Disorganized Steroidogenesis in Adrenocortical Carcinoma, a Case Study.

    PubMed

    Uchida, Toyoyoshi; Nishimoto, Koshiro; Fukumura, Yuki; Asahina, Miki; Goto, Hiromasa; Kawano, Yui; Shimizu, Fumitaka; Tsujimura, Akira; Seki, Tsugio; Mukai, Kuniaki; Kabe, Yasuaki; Suematsu, Makoto; Gomez-Sanchez, Celso E; Yao, Takashi; Horie, Shigeo; Watada, Hirotaka

    2017-03-01

    Most adrenocortical carcinomas (ACCs) produce excessive amounts of steroid hormones including aldosterone, cortisol, and steroid precursors. However, aldosterone- and cortisol-producing cells in ACCs have not yet been immunohistochemically described. We present a case of ACC causing mild primary aldosteronism and subclinical Cushing's syndrome. Removal of the tumor cured both conditions. In order to examine the expression patterns of the steroidogenic enzymes responsible for adrenocortical hormone production, 10 tumor portions were immunohistochemically analyzed for aldosterone synthase (CYP11B2), 11β-hydroxylase (CYP11B1, cortisol-synthesizing enzyme), 3β-hydroxysteroid dehydrogenase (3βHSD, upstream enzyme for both CYP11B2 and CYP11B1), and 17α-hydroxylase/C17-20 lyase (CYP17, upstream enzyme for CYP11B1, but not for CYP11B1). CYP11B2, CYP11B1, and 3βHSD were expressed sporadically, and their expression patterns varied significantly among the different tumor portions examined. The expression of these enzymes was random and not associated with each other. CYP17 was expressed throughout the tumor, even in CYP11B2-positive cells. Small tumor cell populations were aldosterone- or cortisol-producing cells, as judged by 3βHSD coinciding with either CYP11B2 or CYP11B1, respectively. These results suggest that the tumor produced limited amounts of aldosterone and cortisol due to the lack of the coordinated expression of steroidogenic enzymes, which led to mild clinical expression in this case. We delineated the expression patterns of steroidogenic enzymes in ACC. The coordinated expression of steroidogenic enzymes in normal and adenoma cells was disturbed in ACC cells, resulting in the inefficient production of steroid hormones in relation to the large tumor volume.

  13. Nitric oxide synthase mRNA expression in human fetal membranes: a possible role in parturition.

    PubMed

    Dennes, W J; Slater, D M; Bennett, P R

    1997-04-07

    Nitric oxide (NO) is a potent endogenous smooth-muscle relaxant. It is synthesised from 1-arginine by isoforms of nitric oxide synthase (NOS). Whilst it is clear that the uterus responds to NO by relaxation, NOS expression has not been investigated in fetal membranes or myometrium in human pregnancy. This study has shown, using semi-quantitative RT-PCR, expression of cNOS mRNA in human amnion, chorion-decidua, and placenta. iNOS mRNA expression was demonstrated in human amnion, chorion-decidua, and placenta. It is possible that NO synthesised in fetal membranes may act either directly to inhibit myometrial contractility or indirectly to interact with other labour-associated genes, such as cyclo-oxygenase, to coordinate the onset of labour.

  14. High Polyhydroxybutyrate Production in Pseudomonas extremaustralis Is Associated with Differential Expression of Horizontally Acquired and Core Genome Polyhydroxyalkanoate Synthase Genes

    PubMed Central

    Catone, Mariela V.; Ruiz, Jimena A.; Castellanos, Mildred; Segura, Daniel; Espin, Guadalupe; López, Nancy I.

    2014-01-01

    Pseudomonas extremaustralis produces mainly polyhydroxybutyrate (PHB), a short chain length polyhydroxyalkanoate (sclPHA) infrequently found in Pseudomonas species. Previous studies with this strain demonstrated that PHB genes are located in a genomic island. In this work, the analysis of the genome of P. extremaustralis revealed the presence of another PHB cluster phbFPX, with high similarity to genes belonging to Burkholderiales, and also a cluster, phaC1ZC2D, coding for medium chain length PHA production (mclPHA). All mclPHA genes showed high similarity to genes from Pseudomonas species and interestingly, this cluster also showed a natural insertion of seven ORFs not related to mclPHA metabolism. Besides PHB, P. extremaustralis is able to produce mclPHA although in minor amounts. Complementation analysis demonstrated that both mclPHA synthases, PhaC1 and PhaC2, were functional. RT-qPCR analysis showed different levels of expression for the PHB synthase, phbC, and the mclPHA synthases. The expression level of phbC, was significantly higher than the obtained for phaC1 and phaC2, in late exponential phase cultures. The analysis of the proteins bound to the PHA granules showed the presence of PhbC and PhaC1, whilst PhaC2 could not be detected. In addition, two phasin like proteins (PhbP and PhaI) associated with the production of scl and mcl PHAs, respectively, were detected. The results of this work show the high efficiency of a foreign gene (phbC) in comparison with the mclPHA core genome genes (phaC1 and phaC2) indicating that the ability of P. extremaustralis to produce high amounts of PHB could be explained by the different expression levels of the genes encoding the scl and mcl PHA synthases. PMID:24887088

  15. Local Renin Angiotensin Aldosterone Systems and Cardiovascular Diseases.

    PubMed

    De Mello, Walmor C

    2017-01-01

    The presence of local renin angiotensin aldosterone systems (RAAS) in the cardiovascular and renal tissues and their influence in cardiovascular and renal diseases are described. The fundamental role of ACE/Ang II/AT1 receptor axis activation as well the counterregulatory role of ACE2/Ang (1-7)/Mas receptor activation on cardiovascular and renal physiology and pathology are emphasized. The presence of a local RAS and its influence on hypertension is discussed, and finally, the hypothesis that epigenetic factors change the RAAS in utero and induce the expression of renin or Ang II inside the cells of the cardiovascular system is presented. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Decreased plasma prorenin levels in primary aldosteronism: potential diagnostic implications.

    PubMed

    Berge, Constance; Courand, Pierre-Yves; Harbaoui, Brahim; Paget, Vinciane; Khettab, Fouad; Bricca, Giampiero; Fauvel, Jean-Pierre; Lantelme, Pierre

    2015-01-01

    Primary aldosteronism could exert a negative feedback on prorenin secretion, of possibly different magnitude, whether it is related to an aldosterone-producing adenoma (APA) or an idiopathic hyperaldosteronism (IHA). The objectives of this study were to evaluate the level of prorenin in three subgroups: APA, IHA, and essential hypertension; and the performance of the aldosterone-to-prorenin ratio (APR) for the diagnosis of an APA. Seven hundred and forty-six hypertensive patients with a standardized work-up, including a prorenin measurement, were considered. Ninety-six patients without neutral treatment and 38 patients with other forms of secondary hypertension were excluded. APA and IHA were categorized according to computed tomography scan, adrenal venous sampling, pathological analysis and improvement of hypertension after surgery. Thirty-five patients had a diagnosis of APA, 57 of IHA and 504 of essential hypertension. Prorenin was lower in APA and IHA than in essential hypertension (32.9, 40.4 and 50.3  pg/ml, respectively; P < 0.001). APR was higher in patients with APA and IHA than in those with essential hypertension (24.0, 11.8, and 4.0  pmol/l per pg/ml, respectively; P < 0.001). The APR was more discriminant than the aldosterone-to-renin ratio to identify APA compared to IHA (area under the receiver operating curve at 0.750 and 0.639, respectively; P = 0.04). The optimal cut-off values were 22  pmol/l per pg/ml for APR (sensitivity 57.0%, specificity 93.0%) and 440  pmol/l per pg/ml for aldosterone-to-renin ratio (sensitivity 54.3%, specificity 82.5%). Primary aldosteronism and particularly its most caricatural form, that is APA, seems associated with a lower level of prorenin than essential hypertension. The APR could be included in the diagnostic strategy of APA.

  17. Effects and mechanism of acid rain on plant chloroplast ATP synthase.

    PubMed

    Sun, Jingwen; Hu, Huiqing; Li, Yueli; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

    2016-09-01

    Acid rain can directly or indirectly affect plant physiological functions, especially photosynthesis. The enzyme ATP synthase is the key in photosynthetic energy conversion, and thus, it affects plant photosynthesis. To clarify the mechanism by which acid rain affects photosynthesis, we studied the effects of acid rain on plant growth, photosynthesis, chloroplast ATP synthase activity and gene expression, chloroplast ultrastructure, intracellular H(+) level, and water content of rice seedlings. Acid rain at pH 4.5 remained the chloroplast structure unchanged but increased the expression of six chloroplast ATP synthase subunits, promoted chloroplast ATP synthase activity, and increased photosynthesis and plant growth. Acid rain at pH 4.0 or less decreased leaf water content, destroyed chloroplast structure, inhibited the expression of six chloroplast ATP synthase subunits, decreased chloroplast ATP synthase activity, and reduced photosynthesis and plant growth. In conclusion, acid rain affected the chloroplast ultrastructure, chloroplast ATPase transcription and activity, and P n by changing the acidity in the cells, and thus influencing the plant growth and development. Finally, the effects of simulated acid rain on the test indices were found to be dose-dependent.

  18. Prevalence of and risk factors for primary aldosteronism among patients with resistant hypertension in China.

    PubMed

    Sang, Xiaojing; Jiang, Yiran; Wang, Weiqing; Yan, Li; Zhao, Jiasheng; Peng, Yongde; Gu, Wei; Chen, Gang; Liu, Wei; Ning, Guang

    2013-07-01

    It is estimated that there are more than 16 million adults with drug-resistant hypertension in China. Nevertheless, the prevalence of and risk factors for primary aldosteronism, a highly curable condition among adults with drug-resistant hypertension, has not been fully investigated. Between January 2010 and October 2011, a multicenter epidemiologic study was conducted among 1656 patients with resistant hypertension in 11 provinces of China. Serum aldosterone and plasma renin activity were measured in every participant and aldosterone-to-renin ratio (ARR) was calculated. Patients with ARR more than 20 underwent an intravenous (i.v.) sodium infusion test, and diagnosis of primary aldosteronism was established by the presence of unsuppressed postinfusion aldosterone (>8 ng/dl). Patients with biochemically proved primary aldosteronism then underwent adrenal computed tomography (CT) scanning and adrenal vein sampling (AVS) for subtype classification. Among the 1656 patients, 494 (29.8%) had ARR greater than 20 and underwent i.v. sodium infusion. Of these 494, 118 were diagnosed as primary aldosteronism, yielding a prevalence of 7.1% (95% confidential interval 5.9-8.3%). Seventy of the 118 patients were categorized into unilateral (39) and bilateral (31) by AVS. Generalized additive regression analysis revealed that among all the factors investigated (age of hypertension onset, BMI, family history of hypertension, cigarette smoking, alcohol consumption, diabetes, serum potassium, hyperlipidemia, and creatinine), only age of hypertension onset and serum potassium were independently associated with the presence of primary aldosteronism. The prevalence of primary aldosteronism among Chinese patients with resistant hypertension is relatively lower than that reported previously for other ethnic populations. The screening for primary aldosteronism should be focused on those with early onset hypertension and/or hypokalemia.

  19. Germacrene C synthase from Lycopersicon esculentum cv. VFNT Cherry tomato: cDNA isolation, characterization, and bacterial expression of the multiple product sesquiterpene cyclase

    PubMed Central

    Colby, Sheila M.; Crock, John; Dowdle-Rizzo, Barbara; Lemaux, Peggy G.; Croteau, Rodney

    1998-01-01

    Germacrene C was found by GC-MS and NMR analysis to be the most abundant sesquiterpene in the leaf oil of Lycopersicon esculentum cv. VFNT Cherry, with lesser amounts of germacrene A, guaia-6,9-diene, germacrene B, β-caryophyllene, α-humulene, and germacrene D. Soluble enzyme preparations from leaves catalyzed the divalent metal ion-dependent cyclization of [1-3H]farnesyl diphosphate to these same sesquiterpene olefins, as determined by radio-GC. To obtain a germacrene synthase cDNA, a set of degenerate primers was constructed based on conserved amino acid sequences of related terpenoid cyclases. With cDNA prepared from leaf epidermis-enriched mRNA, these primers amplified a 767-bp fragment that was used as a hybridization probe to screen the cDNA library. Thirty-one clones were evaluated for functional expression of terpenoid cyclase activity in Escherichia coli by using labeled geranyl, farnesyl, and geranylgeranyl diphosphates as substrates. Nine cDNA isolates expressed sesquiterpene synthase activity, and GC-MS analysis of the products identified germacrene C with smaller amounts of germacrene A, B, and D. None of the expressed proteins was active with geranylgeranyl diphosphate; however, one truncated protein converted geranyl diphosphate to the monoterpene limonene. The cDNA inserts specify a deduced polypeptide of 548 amino acids (Mr = 64,114), and sequence comparison with other plant sesquiterpene cyclases indicates that germacrene C synthase most closely resembles cotton δ-cadinene synthase (50% identity). PMID:9482865

  20. Aldosterone and renin in cardiac patients referred for catheterization.

    PubMed

    Erne, Paul; Müller, Andrea; Rossi, Gian Paolo; Seifert, Burkhardt; Stehlin, Fabrice; Redondo, Maurice; Bauer, Peter T; Kobza, Richard; Resink, Therese J; Radovanovic, Dragana

    2017-06-01

    Little is known regarding alterations of the renin-angiotensin system in patients referred for cardiac catheterization. Here, we measured plasma levels of active renin and aldosterone in patients referred for cardiac catheterization in order to determine the prevalence of elevated renin, aldosterone, and the aldosterone-renin ratio.A chemiluminescence assay was used to measure plasma aldosterone concentration (PAC) and active renin levels in 833 consecutive patients, after an overnight fasting and without any medication for least 12 hours. We evaluated associations of the hormonal elevations in relation to hypertension, atrial fibrillation (AF), hypertensive cardiomyopathy, coronary artery disease (CAD), valvular disease, impaired left ventricular ejection fraction (LVEF < 35%), and pulmonary hypertension (arterial pulmonary mean pressure >25 mm Hg).Hyperaldosteronism occurred in around one-third of all examined patients, without significant differences between patients with or without the named cardiac diseases. In a comparison between patients with or without any given cardiac disease condition, renin was significantly elevated in patients with either hypertension (36.4% vs 15.9%), CAD (33.9% vs 22.1%), or impaired LVEF (47.3% vs 24.8%). The angiotensin-renin ratio was elevated in AF patients and in patients with hypertensive cardiomyopathy. Patients with AF and coexisting hypertension had elevated renin more frequently than AF patients without coexisting hypertension (35.3% vs 16.5%; P  =  .005). Patients with persistent/permanent AF more frequently had elevated renin than patients with paroxysmal AF (34.1% vs 15.8%; P  =  .007).This prospective study of consecutive cardiac disease patients referred for cardiac catheterization has revealed distinct cardiac disease condition-associated differences in the frequencies of elevations in plasma renin, PAC, and the aldosterone-renin ratio.

  1. Bilateral aldosterone-producing adenomas: differentiation from bilateral adrenal hyperplasia.

    PubMed

    Wu, V C; Chueh, S C; Chang, H W; Lin, W C; Liu, K L; Li, H Y; Lin, Y H; Wu, K D; Hsieh, B S

    2008-01-01

    Primary aldosteronism (PA) is a common curable disease of secondary hypertension. Most such patients have either idiopathic bilateral adrenal hyperplasia (BAH) or unilateral aldosterone-producing adenoma (APA). Bilateral APAs are reportedly extremely rare. To compare the distinctive characteristics, clinical course, and outcomes of bilateral APA vs. BAH. Retrospective record review. From July 1994 to Jan 2007, 190 patients diagnosed with PA underwent surgical intervention at our hospital. Bilateral APA was diagnosed in 7/164 patients with histologically-proven APA. Twenty-one patients diagnosed as BAH, and 21 randomly selected of unilateral APA patients, matched by age and sex served as controls. Patients with bilateral APA had similar blood pressure, arterial blood gas analysis, spot urinary potassium to creatinine ratio and clinical symptoms to those with BAH, but lower serum potassium levels (p = 0.027), lower plasma renin activity (p = 0.037), and higher plasma aldosterone concentrations (p = 0.029). Aldosterone-renin ratio (ARR) after administration of 50 mg captopril was higher in bilateral APA than in BAH patients (p = 0.023), but not different between unilateral APA and BAH (p = 0.218). A cut-off of ARR >100 ng/dl per ng/ml/h and plasma aldosterone >20 ng/dl after captopril significantly differentiated bilateral APA from BAH. Bilateral subtotal adrenalectomy normalized blood pressure and biochemistry in all patients with bilateral APA. Bilateral APA, presenting simultaneously or sequentially, may not be a rare disease, accounting for 4.3% of APA in this sample. The clinical presentations of bilateral functional adenoma are not different from BAH, but patients with low serum potassium and ARR >100 after captopril should be carefully evaluated for bilateral adenoma.

  2. Potential for quantifying expression of the Geobacteraceae citrate synthase gene to assess the activity of Geobacteraceae in the subsurface and on current-harvesting electrodes

    USGS Publications Warehouse

    Holmes, Dawn E.; Nevin, Kelly P.; O'Neil, Regina A.; Ward, Joy E.; Adams, Lorrie A.; Woodard, Trevor L.; Vrionis, Helen A.; Lovely, Derek R.

    2005-01-01

    The Geobacteraceae citrate synthase is phylogenetically distinct from those of other prokaryotes and is a key enzyme in the central metabolism of Geobacteraceae. Therefore, the potential for using levels of citrate synthase mRNA to estimate rates of Geobacter metabolism was evaluated in pure culture studies and in four different Geobacteraceae-dominated environments. Quantitative reverse transcription-PCR studies with mRNA extracted from cultures of Geobacter sulfurreducens grown in chemostats with Fe(III) as the electron acceptor or in batch with electrodes as the electron acceptor indicated that transcript levels of the citrate synthase gene, gltA, increased with increased rates of growth/Fe(III) reduction or current production, whereas the expression of the constitutively expressed housekeeping genes recA, rpoD, and proC remained relatively constant. Analysis of mRNA extracted from groundwater collected from a U(VI)-contaminated site undergoing in situ uranium bioremediation revealed a remarkable correspondence between acetate levels in the groundwater and levels of transcripts of gltA. The expression of gltA was also significantly greater in RNA extracted from groundwater beneath a highway runoff recharge pool that was exposed to calcium magnesium acetate in June, when acetate concentrations were high, than in October, when the levels had significantly decreased. It was also possible to detect gltA transcripts on current-harvesting anodes deployed in freshwater sediments. These results suggest that it is possible to monitor the in situ metabolic rate of Geobacteraceae by tracking the expression of the citrate synthase gene.

  3. Prevalence and Characterization of Somatic Mutations in Chinese Aldosterone-Producing Adenoma Patients

    PubMed Central

    Wang, Baojun; Li, Xintao; Zhang, Xu; Ma, Xin; Chen, Luyao; Zhang, Yu; Lyu, Xiangjun; Tang, Yuzhe; Huang, Qingbo; Gao, Yu; Fan, Yang; Ouyang, Jinzhi

    2015-01-01

    Abstract Recently somatic mutations of KCNJ5, ATP1A1, ATP2B3, and CACNA1D have been identified in patients with aldosterone-producing adenoma (APA). The present study sequenced the DNA in the tissues and blood samples from Chinese patients with APA for KCNJ5, ATP1A1, ATP2B3, and CACNA1D gene mutations. Among the 114 patients, 86 (75.4%) were identified with KCNJ5 somatic mutations, including 3 previously reported (G151R, L168R, T158A) and 2 other unreported mutations. One patient presented with both a point mutation (E147) and an insertion mutation, whereas another had a 36-base duplication, G153_G164dup. No mutation of ATP1A1 and ATP2B3 in the known hotspots was identified and only 1 male patient was detected with a novel CACNA1D mutation, V748I. Unlike other studies, male and female patients had similar KCNJ5 mutation rates (76.9% vs 74.2%). Mutation carriers were younger and had lower preoperative potassium level, whereas male (but not female) mutation carriers had higher preoperative plasma aldosterone concentration and preoperative blood pressures. Mutation carriers also had higher LV mass index (LVMI) than nonmutation carriers. After surgery, LVMI improved significantly in the KCNJ5 mutation group but not in the nonmutation group. The mRNA expression of KCNJ5, CYP11B2, and ATP2B3 was higher in the KCNJ5-mutated APA tissues. Functional characterization of the 2 novel KCNJ5 mutations showed that they were associated with decreased proliferation, membrane depolarization, elevated secretion of aldosterone, and increased expression of CYP11B1 and CYP11B2. In conclusion, Chinese APA patients appear to have a high frequency of somatic KCNJ5 mutation. Mutation prevalence rates are similar among men and women and 2 novel mutations are identified. KCNJ5-mutated patients benefit more from surgical resection of APA than nonmutated patients. PMID:25906099

  4. Aldosterone Is Not Associated With Metabolic and Microvascular Insulin Sensitivity in Abdominally Obese Men.

    PubMed

    Schütten, Monica T J; Kusters, Yvo H A M; Houben, Alfons J H M; Scheijen, Jean L J M; van de Waarenburg, Marjo P H; Schalkwijk, Casper G; Joris, Peter J; Plat, Jogchum; Mensink, Ronald P; de Leeuw, Peter W; Stehouwer, Coen D A

    2018-02-01

    Impaired insulin-mediated muscle microvascular recruitment (IMMR) may add to the development of insulin resistance and hypertension. Increased aldosterone levels have been linked to these obesity-related complications in severely to morbidly obese individuals and to impaired microvascular function in experimental studies. To investigate whether aldosterone levels are associated with IMMR, insulin sensitivity, and blood pressure in lean and moderately abdominally obese men, and to study the effect of weight loss. In 25 lean and 53 abdominally obese men, 24-hour blood pressure measurement was performed, and aldosterone levels were measured using ultra-performance liquid chromatography tandem mass spectrometry. Insulin sensitivity was assessed by determining whole-body glucose disposal during a hyperinsulinemic clamp. IMMR in forearm skeletal muscle was measured with contrast-enhanced ultrasonography. These assessments were repeated in the abdominally obese men following an 8-week weight loss or weight stable period. Sodium excretion and aldosterone levels were similar in lean and abdominally obese participants, but sodium excretion was inversely associated with aldosterone concentration only in the lean individuals [lean, β/100 mmol sodium excretion (adjusted for age and urinary potassium excretion) = -0.481 (95% confidence interval, -0.949 to -0.013); abdominally obese, β/100 mmol sodium excretion = -0.081 (95% confidence interval, -0.433 to 0.271); P for interaction = 0.02]. Aldosterone was not associated with IMMR, insulin sensitivity, or blood pressure and was unaffected by weight loss. In moderately abdominally obese men, the inverse relationship between sodium excretion and aldosterone concentration is less than that in lean men but does not translate into higher aldosterone levels. The absolute aldosterone level does not explain differences in microvascular and metabolic insulin sensitivity and blood pressure between lean and moderately abdominally obese men

  5. Seated saline suppression testing for the diagnosis of primary aldosteronism: a preliminary study.

    PubMed

    Ahmed, Ashraf H; Cowley, Diane; Wolley, Martin; Gordon, Richard D; Xu, Shengxin; Taylor, Paul J; Stowasser, Michael

    2014-08-01

    Failure of aldosterone suppression by sodium loading during fludrocortisone suppression testing (FST) or saline suppression testing (SST) confirms primary aldosteronism (PA). We previously found recumbent SST (RSST) to lack sensitivity. Aldosterone levels can be higher upright (e.g. seated) than recumbent in patients with PA and upright levels are used during FST. We therefore hypothesized that seated SST (SSST) is more sensitive than RSST, especially for posture-responsive PA. Of 66 patients who underwent FST (upright plasma aldosterone levels measured at 10am basally and after 4 days fludrocortisone 0.1 mg 6-hourly and oral salt loading), 31 underwent SST (aldosterone levels measured basally at 8am and after infusion of 2 L normal saline over 4h) both recumbent and seated in randomized order and at least 2 weeks apart. FST confirmed PA in 23 of 31 patients (day 4 upright aldosterone level >165 pmol/L), excluded PA in three and was originally "inconclusive" in five. However, one with "inconclusive" FST had PA confirmed by lateralizing AVS and was reclassified "unilateral PA". Of 24 with confirmed PA (eight unilateral, 11 bilateral, and five undetermined subtype), 23 (96%) tested positive by SSST (4-h aldosterone level >165 pmol/L) compared with 8 (33%) by RSST (4-h plasma aldosterone level >140 pmol/L) (P < .001). RSST missed one unilateral, all bilateral, and four with as-yet undetermined subtype. RSST was positive in 7 of 10 (70%) posture-unresponsive vs one of 14 (7.1%) posture-responsive patients (P < .005). These preliminary results suggest that seated SST may be superior to recumbent SST in terms of sensitivity for detecting PA, especially posture-responsive forms, and may represent a reliable alternative to FST.

  6. Caveolin 1-related autophagy initiated by aldosterone-induced oxidation promotes liver sinusoidal endothelial cells defenestration.

    PubMed

    Luo, Xiaoying; Dan Wang; Luo, Xuan; Zhu, Xintao; Wang, Guozhen; Ning, Zuowei; Li, Yang; Ma, Xiaoxin; Yang, Renqiang; Jin, Siyi; Huang, Yun; Meng, Ying; Li, Xu

    2017-10-01

    Aldosterone, with pro-oxidation and pro-autophagy capabilities, plays a key role in liver fibrosis. However, the mechanisms underlying aldosterone-promoted liver sinusoidal endothelial cells (LSECs) defenestration remain unknown. Caveolin 1 (Cav1) displays close links with autophagy and fenestration. Hence, we aim to investigate the role of Cav1-related autophagy in LSECs defenestration. We found the increase of aldosterone/MR (mineralocorticoid receptor) level, oxidation, autophagy, and defenestration in LSECs in the human fibrotic liver, BDL or hyperaldosteronism models; while antagonizing aldosterone or inhibiting autophagy relieved LSECs defenestration in BDL-induced fibrosis or hyperaldosteronism models. In vitro, fenestrae of primary LSECs gradually shrank, along with the down-regulation of the NO-dependent pathway and the augment of the AMPK-dependent autophagy; these effects were aggravated by rapamycin (an autophagy activator) or aldosterone treatment. Additionally, aldosterone increased oxidation mediated by Cav1, reduced ATP generation, and subsequently induced the AMPK-dependent autophagy, leading to the down-regulation of the NO-dependent pathway and LSECs defenestration. These effects were reversed by MR antagonist spironolactone, antioxidants or autophagy inhibitors. Besides, aldosterone enhanced the co-immunoprecipitation of Cav1 with p62 and ubiquitin, and induced Cav1 co-immunofluorescence staining with LC3, ubiquitin, and F-actin in the perinuclear area of LSECs. Furthermore, aldosterone treatment increased the membrane protein level of Cav1, whereas decrease the cytoplasmic protein level of Cav1, indicating that aldosterone induced Cav1-related selective autophagy and F-actin remodeling to promote defenestration. Consequently, Cav1-related selective autophagy initiated by aldosterone-induced oxidation promotes LSECs defenestration via activating the AMPK-ULK1 pathway and inhibiting the NO-dependent pathway. Copyright © 2017 The Authors

  7. Bletilla striata polysaccharide stimulates inducible nitric oxide synthase and proinflammatory cytokine expression in macrophages.

    PubMed

    Diao, Huajia; Li, Xin; Chen, Jiangning; Luo, Yi; Chen, Xi; Dong, Lei; Wang, Chunming; Zhang, Chenyu; Zhang, Junfeng

    2008-02-01

    Bletilla striata, a traditional Chinese medicine, has been used for the treatment of alimentary canal mucosal damage, ulcers, bleeding, bruises and burns. B. striata polysaccharide (BSP) isolated from B. striata was found to enhance vascular endothelial cell (EC) proliferation and vascular endothelial growth factor (VEGF) expression. However, the wound healing mechanism of BSP is not well understood. In this study, the results show that treatment with BSP induces coordinate changes in inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-alpha) and interleukin 1 beta (IL-1beta) mRNA levels and enhances the expression of these cytokines, but has no effect on interferon gamma (IFN-gamma) level. In this study, we partially elucidate the wound healing mechanism of BSP.

  8. Microalbuminuria and plasma aldosterone levels in nondiabetic treatment-naïve patients with hypertension.

    PubMed

    Catena, Cristiana; Colussi, GianLuca; Martinis, Flavia; Novello, Marileda; Sechi, Leonardo A

    2017-12-01

    Identification of factors that contribute to urinary albumin losses in hypertensive nephropathy is crucial for prevention of renal deterioration. The aim of this study was to investigate the relationship of low-grade albuminuria with plasma aldosterone levels in treatment-naïve hypertensive patients free of additional comorbidities that might affect renal function. In 242 newly diagnosed patients with uncomplicated primary hypertension, we obtained duplicate 24-h urine collections for measurement of urinary albumin/creatinine ratio (UACR) and measured plasma aldosterone levels. Patients with diabetes, overt proteinuria (>300 mg/day), glomerular filtration rate less than 30 ml/min per 1.73 m, and previous renal diseases were excluded. Increasing UACR was associated with significantly and progressively higher blood pressure (BP), HDL-cholesterol, and plasma aldosterone levels, and with lower glomerular filtration. Microalbuminuria (30-300 mg/day) was detected in 41 (17%) of 242 hypertensive patients, and these patients had significantly higher BP and plasma aldosterone levels (178 ± 113 vs. 128 ± 84 pg/ml; P = 0.001), and lower glomerular filtration than patients without microalbuminuria. UACR was directly and independently correlated with BP and plasma aldosterone levels. In a logistic regression model, presence of microalbuminuria was associated with plasma aldosterone levels independently of glomerular filtration and demographic, anthropometric, and metabolic variables. In nondiabetic, treatment-naïve patients with hypertension, low-grade albuminuria is independently associated with elevated plasma aldosterone. These findings suggest a contribution of aldosterone to the early glomerular changes occurring in hypertensive nephropathy.

  9. Prolonged oral administration of potassium upon aldosterone biosynthesis by rat glomerulosa tissue in vitro.

    PubMed

    Regöly-Mérei, J; Sólyom, J

    1975-01-01

    Steroid production rate of adrenals derived from rats drinking a 0.3 M KC1 + 5% glucose solution for 7 days was compared to that of control rats drinking a 5% glucose solution in order to investigate the effect of potassium loading upon the early and late step of aldosterone biosynthesis. Following potassium loading the quartered adrenals produced more aldosterone but less corticosterone as compared to the control. Potassium loading resulted in an increased aldosterone production rate by capsular adrenals (z. glomerulosa) provided that the corticosterone concentration in the incubation medium was elevated either by incubating it together with the decapsulated adrenal or adding exogenous corticosterone (4--16 mug/ml) to the medium. The corticosterone to aldosterone converting capacity of capsular adrenals is markedly higher in the potassium-loaded rats than in the controls. In the first 15 minutes of incubation the corticosterone production rate of the two groups was equal, aldosterone production rate by capsular adrenals of potassium-loaded rats, being higher than that of control animals. Corticosterone output of capsular adrenals from potassium-loaded rats decreased more rapidly in course of the incubation than it did in control tissue. These results suggest that the increase in aldosterone secretion in vivo following potassium loading is due to the stimulation of conversion of corticosterone to aldosterone in the glomerulosa cells. However, the endogenous corticosterone production during the incubation of glomerulosa cells from pottasium-loaded rats decreases so rapidly that the cells are not capable of producing more aldosterone than the control ones in spite of activated 18-hydroxylase.

  10. Development of Prostaglandin Endoperoxide Synthase Expression in the Ovine Fetal Central Nervous System and Pituitary

    PubMed Central

    Gersting, Jason A.; Schaub, Christine E.; Wood, Charles E.

    2009-01-01

    In this study, we tested the hypothesis that prostaglandin endoperoxide synthase -1 and -2 (PGHS-1 and PGHS-2) are expressed throughout the latter half of gestation in ovine fetal brain and pituitary. Hypothalamus, pituitary, hippocampus, brainstem, cortex and cerebellum were collected from fetal sheep at 80, 100, 120, 130, 145 days of gestational age (DGA), 1 and 7 days postpartum lambs, and from adult ewes (n=4–5 per group). mRNA and protein were isolated from each region, and expression of Prostaglandin Synthase -1 (PGHS-1) and -2 (PGHS-2) were evaluated using real-time RT-PCR and western blot. PGHS-1 and -2 were detected in every brain region at every age tested. Both enzymes were measured in highest abundance in hippocampus and cerebral cortex, and lowest in brainstem and pituitary. PGHS-1 and -2 mRNA’s were upregulated in hypothalamus and pituitary after 100 DGA. The hippocampus exhibited decreases in PGHS-1 and increases in PGHS-2 mRNA after 80 DGA. Brainstem PGHS-1 and -2 and cortex PGHS-2 exhibited robust increases in mRNA postpartum, while cerebellar PGHS-1 and -2 mRNA’s were upregulated at 120 DGA. Tissue concentrations of PGE2 correlated with PGHS-2 mRNA, but not to other variables. We conclude that the regulation of expression of these enzymes is region-specific, suggesting that the activity of these enzymes is likely to be critical for brain development in the late-gestation ovine fetus. PMID:19706338

  11. Molecular genetic studies in a case series of isolated hypoaldosteronism due to biosynthesis defects or aldosterone resistance.

    PubMed

    Turan, Ihsan; Kotan, Leman Damla; Tastan, Mehmet; Gurbuz, Fatih; Topaloglu, Ali Kemal; Yuksel, Bilgin

    2018-06-01

    Hypoaldosteronism is associated with either insufficient aldosterone production or aldosterone resistance (pseudohypoaldosteronism). Patients with aldosterone defects typically present with similar symptoms and findings, which include failure to thrive, vomiting, hyponatremia, hyperkalemia and metabolic acidosis. Accurate diagnosis of these clinical conditions therefore can be challenging. Molecular genetic analyses can help to greatly clarify this complexity. The aim of this study was to obtain an overview of the clinical and genetic characteristics of patients with aldosterone defects due to biosynthesis defects or aldosterone resistance. We investigated the clinical and molecular genetic features of 8 consecutive patients with a clinical picture of aldosterone defects seen in our clinics during the period of May 2015 through October 2017. We screened CYP11B2 for aldosterone synthesis defects and NR3C2 and the three EnaC subunits (SCNN1A, SCNN1B and SCNN1G) for aldosterone resistance. We found 4 novel and 2 previously reported mutations in the genes CYP11B2, NR3C2, SCNN1A and SCNN1G in 9 affected individuals from 7 unrelated families. Molecular genetic investigations can help confidently diagnose these conditions and clarify the pathogenicity of aldosterone defects. This study may expand the clinical and genetic correlations of defects in aldosterone synthesis or resistance. © 2018 John Wiley & Sons Ltd.

  12. Expression and function of glycogen synthase kinase-3 in human hair follicles.

    PubMed

    Yamauchi, Koichi; Kurosaka, Akira

    2010-05-01

    Beta-catenin is involved in the hair follicle morphogenesis and stem cell differentiation, and inhibition of glycogen synthase kinase-3 (GSK-3) increases beta-catenin concentration in the cytoplasm. To examine the effects of GSK-3 inhibition on the hair follicle epithelium, we first examined the expression of GSK-3 in plucked human hair follicles by RT-PCR and found GSK-3 expression in hair follicles. Western blotting with a GSK-3beta-specific antibody, Y174, also demonstrated GSK-3beta expression in the follicles. Moreover, GSK-3beta immunostaining with Y174 showed that GSK-3beta colocalized with hair follicle bulge markers. Contrary to GSK-3beta, GSK-3 alpha was widely expressed throughout the follicles when immunostained with a specific antibody, EP793Y. We then investigated the influence of GSK-3 inhibition. A GSK-3 inhibitor, BIO, promoted the growth of human outer root sheath cells, which could be cultured for up to four passages. The BIO-treated cells exhibited smaller and more undifferentiated morphology than control cells. Moreover, in organ culture of plucked human hair, outer root sheath cells in the middle of a hair follicle proliferated when cultured with BIO. These results indicate that GSK-3beta is expressed in hair bulge stem cells and BIO promotes the growth of ORS cells, possibly by regulating the GSK-3 signaling pathway.

  13. The impact of obstructive sleep apnea syndrome on renin and aldosterone.

    PubMed

    Lykouras, D; Theodoropoulos, K; Sampsonas, F; Lagiou, O; Lykouras, M; Spiropoulou, A; Flordellis, C; Alexandrides, T; Karkoulias, K; Spiropoulos, K

    2015-11-01

    Obstructive Sleep Apnoea Syndrome (OSAS) is a respiratory disorder characterized by recurrent airflow obstruction caused by total or partial collapse of the upper airway. OSAS is an established independent factor of cardiovascular risk together with other risk factors such as smoking and increased lipids. The aim of our study was to measure serum levels of aldosterone and renin in OSAS patients that did not suffer from arterial hypertension and compare them to matched healthy subjects in order to reveal the impact of chronic intermittent hypoxia on the renin-angiotensin-aldosterone system. The patients that enrolled in this study were 19 OSAS patients who had undergone overnight polysomnography and had an Apnoea Hypopnoea Index (AHI) greater than 10 events/hour. They were compared to 20 healthy non-OSAS closely matched controls. Serum aldosterone and direct renin concentration were measured by radioimmunoassay. Aldosterone concentration follows a diurnal variation; therefore, all blood samples were obtained at the same time (6 AM). There were no significant differences in serum aldosterone levels between the two studied groups of OSAS patients and the healthy subjects group (140.6 pg/ml ± 25.2 vs. 133.2 pg/ml ± 18.5 with p = 0.223). Similar were the results for the renin levels (25.0 ± 6.9 vs. 24.9 ± 4.4 with p = 0.360). Our study suggests that patients with OSAS, but without existing hypertension have aldosterone and renin levels similar to healthy subjects. According to our findings a direct connection between OSAS and the development of arterial hypertension may not be established via sympathetic system activation.

  14. Fish Oil Supplementation and Fatty Acid Synthase Expression in the Prostate: A Randomized Controlled Trial. Addendum

    DTIC Science & Technology

    2011-07-01

    controls, Menendez et al demonstrated that addition of omega-3 fatty acids (-3 FA), docosahexanoic acid ( DHA ), alpha- linolenic acid , and -6 FA, γ...AD_________________ Award Number: W81XWH-04-1-0296 TITLE: Fish Oil Supplementation and Fatty Acid ...COVERED 1 March 2010 – 30 June 2011 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Fish Oil Supplementation and Fatty Acid Synthase Expression in the

  15. Expression of thymidylate synthase (TS) and its prognostic significance in patients with cutaneous angiosarcoma.

    PubMed

    Shimizu, A; Kaira, K; Okubo, Y; Utsumi, D; Bolag, A; Yasuda, M; Takahashi, K; Ishikawa, O

    2017-01-01

    Cutaneous angiosarcoma (CA) is extremely rare, and little is known about the biological significance of possible biomarkers for chemotherapeutic agents. Thymidylate synthase (TS) is an attractive target for cancer treatment in various human neoplasms. It remains unclear whether the expression of TS is associated with the clinicopathological features of CA patients. The aim of this study was to elucidate the relationship between TS expression and the clinicopathological significance in CA patients. Fifty-one patients with CA were included in this study. TS expression and Ki-67 labeling index were examined using immunohistochemical analysis. TS was positively expressed in 39% (20/51) of CA patients. No statistically significant prognostic factor was identified as a predictor of overall survival (OS) for all patients by univariate analysis, whereas a significant prognostic variable for progression free survival (PFS) was found to be the clinical stage. In addition, both univariate and multivariate analyses confirmed that positive expression of TS was a significant predictor of worse PFS in CA patients of clinical stage 1. Positive TS expression in CA was identified as a significant predictor of worse outcome in patients of clinical stage 1.

  16. Reversible heart rhythm complexity impairment in patients with primary aldosteronism

    NASA Astrophysics Data System (ADS)

    Lin, Yen-Hung; Wu, Vin-Cent; Lo, Men-Tzung; Wu, Xue-Ming; Hung, Chi-Sheng; Wu, Kwan-Dun; Lin, Chen; Ho, Yi-Lwun; Stowasser, Michael; Peng, Chung-Kang

    2015-08-01

    Excess aldosterone secretion in patients with primary aldosteronism (PA) impairs their cardiovascular system. Heart rhythm complexity analysis, derived from heart rate variability (HRV), is a powerful tool to quantify the complex regulatory dynamics of human physiology. We prospectively analyzed 20 patients with aldosterone producing adenoma (APA) that underwent adrenalectomy and 25 patients with essential hypertension (EH). The heart rate data were analyzed by conventional HRV and heart rhythm complexity analysis including detrended fluctuation analysis (DFA) and multiscale entropy (MSE). We found APA patients had significantly decreased DFAα2 on DFA analysis and decreased area 1-5, area 6-15, and area 6-20 on MSE analysis (all p < 0.05). Area 1-5, area 6-15, area 6-20 in the MSE study correlated significantly with log-transformed renin activity and log-transformed aldosterone-renin ratio (all p < = 0.01). The conventional HRV parameters were comparable between PA and EH patients. After adrenalectomy, all the altered DFA and MSE parameters improved significantly (all p < 0.05). The conventional HRV parameters did not change. Our result suggested that heart rhythm complexity is impaired in APA patients and this is at least partially reversed by adrenalectomy.

  17. Aldosterone and renin in cardiac patients referred for catheterization

    PubMed Central

    Erne, Paul; Müller, Andrea; Rossi, Gian Paolo; Seifert, Burkhardt; Stehlin, Fabrice; Redondo, Maurice; Bauer, Peter T.; Kobza, Richard; Resink, Therese J.; Radovanovic, Dragana

    2017-01-01

    Abstract Little is known regarding alterations of the renin-angiotensin system in patients referred for cardiac catheterization. Here, we measured plasma levels of active renin and aldosterone in patients referred for cardiac catheterization in order to determine the prevalence of elevated renin, aldosterone, and the aldosterone-renin ratio. A chemiluminescence assay was used to measure plasma aldosterone concentration (PAC) and active renin levels in 833 consecutive patients, after an overnight fasting and without any medication for least 12 hours. We evaluated associations of the hormonal elevations in relation to hypertension, atrial fibrillation (AF), hypertensive cardiomyopathy, coronary artery disease (CAD), valvular disease, impaired left ventricular ejection fraction (LVEF < 35%), and pulmonary hypertension (arterial pulmonary mean pressure >25 mm Hg). Hyperaldosteronism occurred in around one-third of all examined patients, without significant differences between patients with or without the named cardiac diseases. In a comparison between patients with or without any given cardiac disease condition, renin was significantly elevated in patients with either hypertension (36.4% vs 15.9%), CAD (33.9% vs 22.1%), or impaired LVEF (47.3% vs 24.8%). The angiotensin-renin ratio was elevated in AF patients and in patients with hypertensive cardiomyopathy. Patients with AF and coexisting hypertension had elevated renin more frequently than AF patients without coexisting hypertension (35.3% vs 16.5%; P  =  .005). Patients with persistent/permanent AF more frequently had elevated renin than patients with paroxysmal AF (34.1% vs 15.8%; P  =  .007). This prospective study of consecutive cardiac disease patients referred for cardiac catheterization has revealed distinct cardiac disease condition-associated differences in the frequencies of elevations in plasma renin, PAC, and the aldosterone-renin ratio. PMID:28640140

  18. Reversed association between aldosterone and mortality in hemodialysis patients: Role of volume overload.

    PubMed

    Hung, Szu-Chun; Tarng, Der-Cherng

    2016-07-01

    The role of aldosterone has expanded from its genomic effects that involve renal sodium transport to nongenomic effects such as cardiac and renal fibrosis. Elevated aldosterone levels are associated with increased mortality in the general population. However, the association is reversed in patients with end-stage renal disease on maintenance hemodialysis. We have shown that the inverse association between aldosterone and mortality in hemodialysis patients is due to the confounding effect of volume overload. Volume overload, which is prevalent in patients with chronic kidney disease, is associated with both lower aldosterone concentrations and higher mortality. Our findings support salt and water restriction and treatment of hyperaldosteronemia in hemodialysis patients who have achieved strict volume control. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Effect of a multistage ultraendurance triathlon on aldosterone, vasopressin, extracellular water and urine electrolytes.

    PubMed

    Knechtle, B; Morales, N P Hernández; González, E Ruvalcaba; Gutierrez, A A Aguirre; Sevilla, J Noriega; Gómez, R Amézquita; Robledo, A R Estrada; Rodríguez, A L Marroquín; Fraire, O Salas; Andonie, J L; Lopez, L C; Kohler, G; Rosemann, T

    2012-02-01

    Prolonged endurance exercise over several days induces increase in extracellular water (ECW). We aimed to investigate an association between the increase in ECW and the change in aldosterone and vasopressin in a multistage ultraendurance triathlon, the 'World Challenge Deca Iron Triathlon' with 10 Ironman triathlons within 10 days. Before and after each Ironman, body mass, ECW, urinary [Na(+)], urinary [K(+)], urinary specific gravity, urinary osmolality and aldosterone and vasopressin in plasma were measured. The 11 finishers completed the total distance of 38 km swimming, 1800 km cycling and 422 km running within 145.5 (18.8) hours and 25 (22) minutes. ECW increased by 0.9 (1.1) L from 14.6 (1.5) L prerace to 15.5 (1.9) L postrace (P < 0.0001). Aldosterone increased from 70.8 (104.5) pg/mL to 102.6 (104.6) pg/mL (P = 0.033); vasopressin remained unchanged. The increase in ECW was related neither to postrace aldosterone nor to postrace vasopressin. In conclusion, ECW and aldosterone increased after this multistage ultraendurance triathlon, but vasopressin did not. The increase in ECW and the increase in aldosterone were not associated.

  20. Molecular cloning and expression of Chimonanthus praecox farnesyl pyrophosphate synthase gene and its possible involvement in the biosynthesis of floral volatile sesquiterpenoids.

    PubMed

    Xiang, Lin; Zhao, Kaige; Chen, Longqing

    2010-01-01

    Farnesyl pyrophosphate (FPP) synthase catalyzes the biosynthesis of FPP, which is the precursors of sesquiterpenoids such as floral scent volatiles, from isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP). cDNA encoding wintersweet (Chimonanthus praecox L.) FPP synthase was isolated by the RT-PCR and RACE methods. The deduced amino acid sequence showed a high identity to plant FPP synthases. Expression of the gene in Escherichia coli yielded FPPS activity that catalyzed the synthesis of FPP as a main product. Tissue-specific and developmental analyses of the mRNA levels of CpFPPS and volatile sesquiterpenoids levels in C. praecox flowers revealed that the FPPS may play a regulatory role in floral volatile sesquiterpenoids of wintersweet. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  1. Zinc affects differently growth, photosynthesis, antioxidant enzyme activities and phytochelatin synthase expression of four marine diatoms.

    PubMed

    Nguyen-Deroche, Thi Le Nhung; Caruso, Aurore; Le, Thi Trung; Bui, Trang Viet; Schoefs, Benoît; Tremblin, Gérard; Morant-Manceau, Annick

    2012-01-01

    Zinc-supplementation (20 μM) effects on growth, photosynthesis, antioxidant enzyme activities (superoxide dismutase, ascorbate peroxidase, catalase), and the expression of phytochelatin synthase gene were investigated in four marine diatoms (Amphora acutiuscula, Nitzschia palea, Amphora coffeaeformis and Entomoneis paludosa). Zn-supplementation reduced the maximum cell density. A linear relationship was found between the evolution of gross photosynthesis and total chlorophyll content. The Zn treatment decreased the electron transport rate except in A. coffeaeformis and in E. paludosa at high irradiance. A linear relationship was found between the efficiency of light to evolve oxygen and the size of the light-harvesting antenna. The external carbonic anhydrase activity was stimulated in Zn-supplemented E. paludosa but was not correlated with an increase of photosynthesis. The total activity of the antioxidant enzymes did not display any clear increase except in ascorbate peroxidase activity in N. palea. The phytochelatin synthase gene was identified in the four diatoms, but its expression was only revealed in N. palea, without a clear difference between control and Zn-supplemented cells. Among the four species, A. paludosa was the most sensitive and A. coffeaeformis, the most tolerant. A. acutiuscula seemed to be under metal starvation, whereas, to survive, only N. palea developed several stress responses.

  2. Zinc Affects Differently Growth, Photosynthesis, Antioxidant Enzyme Activities and Phytochelatin Synthase Expression of Four Marine Diatoms

    PubMed Central

    Nguyen-Deroche, Thi Le Nhung; Caruso, Aurore; Le, Thi Trung; Bui, Trang Viet; Schoefs, Benoît; Tremblin, Gérard; Morant-Manceau, Annick

    2012-01-01

    Zinc-supplementation (20 μM) effects on growth, photosynthesis, antioxidant enzyme activities (superoxide dismutase, ascorbate peroxidase, catalase), and the expression of phytochelatin synthase gene were investigated in four marine diatoms (Amphora acutiuscula, Nitzschia palea, Amphora coffeaeformis and Entomoneis paludosa). Zn-supplementation reduced the maximum cell density. A linear relationship was found between the evolution of gross photosynthesis and total chlorophyll content. The Zn treatment decreased the electron transport rate except in A. coffeaeformis and in E. paludosa at high irradiance. A linear relationship was found between the efficiency of light to evolve oxygen and the size of the light-harvesting antenna. The external carbonic anhydrase activity was stimulated in Zn-supplemented E. paludosa but was not correlated with an increase of photosynthesis. The total activity of the antioxidant enzymes did not display any clear increase except in ascorbate peroxidase activity in N. palea. The phytochelatin synthase gene was identified in the four diatoms, but its expression was only revealed in N. palea, without a clear difference between control and Zn-supplemented cells. Among the four species, A. paludosa was the most sensitive and A. coffeaeformis, the most tolerant. A. acutiuscula seemed to be under metal starvation, whereas, to survive, only N. palea developed several stress responses. PMID:22645501

  3. Gene expression profiles of peripheral blood mononuclear cells reveal transcriptional signatures as novel biomarkers of cardiac remodeling in rats with aldosteronism and hypertensive heart disease.

    PubMed

    Gerling, Ivan C; Ahokas, Robert A; Kamalov, German; Zhao, Wenyuan; Bhattacharya, Syamal K; Sun, Yao; Weber, Karl T

    2013-12-01

    In searching for a noninvasive surrogate tissue mimicking the pro-oxidant/proinflammatory hypertensive heart disease (HHD) phenotype, we turned to peripheral blood mononuclear cells (PBMCs). We tested whether iterations in [Ca2+]i, [Zn2+]i, and oxidative stress in cardiomyocytes and PBMCs would complement each other, eliciting similar shifts in gene expression profiles in these tissues demonstrable during the preclinical (week 1) and pathological (week 4) stages of aldosterone/salt treatment (ALDOST). Inappropriate neurohormonal activation contributes to pathological remodeling of myocardium in HHD associated with aldosteronism. In rats receiving long-term ALDOST, evidence of reparative fibrosis replacing necrotic cardiomyocytes and coronary vasculopathy appears at week 4 associated with the induction of oxidative stress by mitochondria that overwhelms endogenous, largely Zn2+-based, antioxidant defenses. Biomarker-guided prediction of risk before the appearance of cardiac pathology would prove invaluable. In PBMCs and cardiomyocytes, quantitation of cytoplasmic free Ca2+ and Zn2+, H2O2, and 8-iosprostane levels and isolation of ribonucleic acid (RNA) and gene expression together with statistical and clustering analyses and confirmation of genes by in situ hybridization and reverse-transcription polymerase chain reaction were performed. Compared with controls, at weeks 1 and 4 of ALDOST, we found comparable increments in [Ca2+]i, [Zn2+]i, and 8-isoprotane coupled with increased H2O2 production in cardiac mitochondria and PBMCs, together with the common networks of expression profiles dominated by genes involved in oxidative stress, inflammation, and repair. These included 3 central Ingenuity pathway-linked genes: p38 mitogen-activated protein kinase, a stress-responsive protein; nuclear factor-κB, a redox-sensitive transcription factor and a proinflammatory cascade that it regulates; and transforming growth factor-β1, a fibrogenic cytokine involved in tissue

  4. Differential Expression of Biphenyl Synthase Gene Family Members in Fire-Blight-Infected Apple ‘Holsteiner Cox’ 1[W][OA

    PubMed Central

    Chizzali, Cornelia; Gaid, Mariam M.; Belkheir, Asma K.; Hänsch, Robert; Richter, Klaus; Flachowsky, Henryk; Peil, Andreas; Hanke, Magda-Viola; Liu, Benye; Beerhues, Ludger

    2012-01-01

    Fire blight, caused by the bacterium Erwinia amylovora, is a devastating disease of apple (Malus × domestica). The phytoalexins of apple are biphenyls and dibenzofurans, whose carbon skeleton is formed by biphenyl synthase (BIS), a type III polyketide synthase. In the recently published genome sequence of apple ‘Golden Delicious’, nine BIS genes and four BIS gene fragments were detected. The nine genes fall into four subfamilies, referred to as MdBIS1 to MdBIS4. In a phylogenetic tree, the BIS amino acid sequences from apple and Sorbus aucuparia formed an individual cluster within the clade of the functionally diverse type III polyketide synthases. cDNAs encoding MdBIS1 to MdBIS4 were cloned from fire-blight-infected shoots of apple ‘Holsteiner Cox,’ heterologously expressed in Escherichia coli, and functionally analyzed. Benzoyl-coenzyme A and salicoyl-coenzyme A were the preferred starter substrates. In response to inoculation with E. amylovora, the BIS3 gene was expressed in stems of cv Holsteiner Cox, with highest transcript levels in the transition zone between necrotic and healthy tissues. The transition zone was the accumulation site of biphenyl and dibenzofuran phytoalexins. Leaves contained transcripts for BIS2 but failed to form immunodetectable amounts of BIS protein. In cell cultures of apple ‘Cox Orange,’ expression of the BIS1 to BIS3 genes was observed after the addition of an autoclaved E. amylovora suspension. Using immunofluorescence localization under a confocal laser-scanning microscope, the BIS3 protein in the transition zone of stems was detected in the parenchyma of the bark. Dot-shaped immunofluorescence was confined to the junctions between neighboring cortical parenchyma cells. PMID:22158676

  5. Subtype Diagnosis of Primary Aldosteronism: Is Adrenal Vein Sampling Always Necessary?

    PubMed Central

    Buffolo, Fabrizio; Monticone, Silvia; Williams, Tracy A.; Rossato, Denis; Burrello, Jacopo; Tetti, Martina; Veglio, Franco; Mulatero, Paolo

    2017-01-01

    Aldosterone producing adenoma and bilateral adrenal hyperplasia are the two most common subtypes of primary aldosteronism (PA) that require targeted and distinct therapeutic approaches: unilateral adrenalectomy or lifelong medical therapy with mineralocorticoid receptor antagonists. According to the 2016 Endocrine Society Guideline, adrenal venous sampling (AVS) is the gold standard test to distinguish between unilateral and bilateral aldosterone overproduction and therefore, to safely refer patients with PA to surgery. Despite significant advances in the optimization of the AVS procedure and the interpretation of hormonal data, a standardized protocol across centers is still lacking. Alternative methods are sought to either localize an aldosterone producing adenoma or to predict the presence of unilateral disease and thereby substantially reduce the number of patients with PA who proceed to AVS. In this review, we summarize the recent advances in subtyping PA for the diagnosis of unilateral and bilateral disease. We focus on the developments in the AVS procedure, the interpretation criteria, and comparisons of the performance of AVS with the alternative methods that are currently available. PMID:28420172

  6. Chlorophyll Synthase under Epigenetic Surveillance Is Critical for Vitamin E Synthesis, and Altered Expression Affects Tocopherol Levels in Arabidopsis.

    PubMed

    Zhang, Chunyu; Zhang, Wei; Ren, Guodong; Li, Delin; Cahoon, Rebecca E; Chen, Ming; Zhou, Yongming; Yu, Bin; Cahoon, Edgar B

    2015-08-01

    Chlorophyll synthase catalyzes the final step in chlorophyll biosynthesis: the esterification of chlorophyllide with either geranylgeranyl diphosphate or phytyl diphosphate (PDP). Recent studies have pointed to the involvement of chlorophyll-linked reduction of geranylgeranyl by geranylgeranyl reductase as a major pathway for the synthesis of the PDP precursor of tocopherols. This indirect pathway of PDP synthesis suggests a key role of chlorophyll synthase in tocopherol production to generate the geranylgeranyl-chlorophyll substrate for geranylgeranyl reductase. In this study, contributions of chlorophyll synthase to tocopherol formation in Arabidopsis (Arabidopsis thaliana) were explored by disrupting and altering expression of the corresponding gene CHLOROPHYLL SYNTHASE (CHLSYN; At3g51820). Leaves from the homozygous chlysyn1-1 null mutant were nearly devoid of tocopherols, whereas seeds contained only approximately 25% of wild-type tocopherol levels. Leaves of RNA interference lines with partial suppression of CHLSYN displayed marked reductions in chlorophyll but up to a 2-fold increase in tocopherol concentrations. Cauliflower mosaic virus35S-mediated overexpression of CHLSYN unexpectedly caused a cosuppression phenotype at high frequencies accompanied by strongly reduced chlorophyll content and increased tocopherol levels. This phenotype and the associated detection of CHLSYN-derived small interfering RNAs were reversed with CHLSYN overexpression in rna-directed rna polymerase6 (rdr6), which is defective in RNA-dependent RNA polymerase6, a key enzyme in sense transgene-induced small interfering RNA production. CHLSYN overexpression in rdr6 had little effect on chlorophyll content but resulted in up to a 30% reduction in tocopherol levels in leaves. These findings show that altered CHLSYN expression impacts tocopherol levels and also, show a strong epigenetic surveillance of CHLSYN to control chlorophyll and tocopherol synthesis. © 2015 American Society of

  7. Divinyl ether synthase gene and protein, and uses thereof

    DOEpatents

    Howe, Gregg A [East Lansing, MI; Itoh, Aya [Tsuruoka, JP

    2011-09-13

    The present invention relates to divinyl ether synthase genes, proteins, and methods of their use. The present invention encompasses both native and recombinant wild-type forms of the synthase, as well as mutants and variant forms, some of which possess altered characteristics relative to the wild-type synthase. The present invention also relates to methods of using divinyl ether synthase genes and proteins, including in their expression in transgenic organisms and in the production of divinyl ether fatty acids, and to methods of suing divinyl ether fatty acids, including in the protection of plants from pathogens.

  8. Divinyl ether synthase gene, and protein and uses thereof

    DOEpatents

    Howe, Gregg A.; Itoh, Aya

    2006-12-26

    The present invention relates to divinyl ether synthase genes, proteins, and methods of their use. The present invention encompasses both native and recombinant wild-type forms of the synthase, as well as mutants and variant forms, some of which possess altered characteristics relative to the wild-type synthase. The present invention also relates to methods of using divinyl ether synthase genes and proteins, including in their expression in transgenic organisms and in the production of divinyl ether fatty acids, and to methods of suing divinyl ether fatty acids, including in the protection of plants from pathogens.

  9. Association of Renin and Aldosterone With Ethnicity and Blood Pressure: The Multi-Ethnic Study of Atherosclerosis

    PubMed Central

    2014-01-01

    BACKGROUND Although variations in plasma renin activity (PRA) and aldosterone have been examined in whites and blacks, the association of these hormones with blood pressure in multiethnic populations has not been described. METHODS We measured PRA and aldosterone in 1,021 participants in the Multi-Ethnic Study of Atherosclerosis not taking antihypertensives and examined the association between ethnicity and PRA/aldosterone and the association between PRA/aldosterone with systolic blood pressure (SBP). RESULTS Average age was 62 (SD = 9) years, and 49% of participants were women. Median PRA was 0.51 (interquartile range (IQR) = 0.29–0.87) ng/ml/hour, and median aldosterone was 12.6 (IQR = 9.1–17.1) ng/dl. After age and sex adjustment, compared with whites, blacks had 28% lower PRA and 17.4% lower aldosterone, and Hispanics had 20.1% higher PRA but similar aldosterone levels. After multivariable adjustment, compared with whites, only Hispanic ethnicity independently associated with higher PRA (0.18ng/ml/hour; 95% confidence interval (CI) = 0.06–0.31). Blacks had lower aldosterone (−1.7ng/dl; 95% CI = −3.2 to −0.2) compared with whites. After multivariable adjustment, PRA was associated with lower SBP in whites (−3.2mm Hg; 95% CI = −5.2 to −1.2 per standardized unit PRA), Chinese (−3.5mm Hg; 95% CI = −6.2 to −0.80 per standardized unit), and Hispanics (−2.3mm Hg; 95% CI = −4.1 to −0.6 per standardized unit) but not blacks. Aldosterone was associated with higher SBP only in Hispanics (2.5mm Hg; 95% CI = 0.4–4.5 per SD). CONCLUSIONS Compared with whites, blacks have lower aldosterone and Hispanics have higher PRA. Aldosterone had significant associations with higher SBP in Hispanics compared with other groups, a finding that may suggest a different mechanism of hypertension. PMID:24436325

  10. Differential cytokine expression in skin graft healing in inducible nitric oxide synthase knockout mice.

    PubMed

    Most, D; Efron, D T; Shi, H P; Tantry, U S; Barbul, A

    2001-10-01

    Inducible nitric oxide synthase (iNOS) and its product, nitric oxide, have been shown to play important roles in wound biology. The present study was performed to investigate the role of iNOS in modulating the cytokine cascade during the complex process of skin graft wound healing.Fifteen iNOS-knockout mice and 15 wild-type C57BL/6J mice were subjected to autogenous 1-cm2 intrascapular full-thickness skin grafts. Three animals in each group were killed on postoperative days 3, 5, 7, 10, and 14. Specimens were then analyzed using nonisotopic in situ hybridization versus mRNA of tumor growth factor-beta1, vascular endothelial growth factor, iNOS, endothelial nitric oxide synthase (eNOS), tumor necrosis factor-alpha, and basic fibroblast growth factor, as well as positive and negative control probes. Positive cells in both grafts and wound beds were counted using a Leica microgrid. Scar thickness was measured with a Leica micrometer. Data were analyzed using the unpaired Student's t test. Expression of iNOS was 2- to 4-fold higher in knockout mice than in wild-type mice on postoperative days 5, 7, and 14. Expression of eNOS was 2- to 2.5-fold higher in knockout mice than in wild-type mice on postoperative days 5 and 7. Tumor necrosis factor-alpha expression was 2- to 7-fold higher in knockout mice than in wild-type mice on all postoperative days. In contrast, expression levels of angiogenic/fibrogenic cytokines (vascular endothelial growth factor, basis fibroblast growth factor, and tumor growth factor-beta1) were 2.5- to 4-fold higher in wild-type mice than in knockout mice. Scars were 1.5- to 2.5-fold thicker in knockout mice than in wild-type mice at all time points. All of the above results represent statistically significant differences (p < 0.05). Significantly different patterns of cytokine expression were seen in knockout and wild-type mice. Although the scar layer was thicker in knockout mice, it showed much greater infiltration with inflammatory cells. These

  11. Novel family of terpene synthases evolved from trans-isoprenyl diphosphate synthases in a flea beetle

    PubMed Central

    Beran, Franziska; Rahfeld, Peter; Luck, Katrin; Nagel, Raimund; Vogel, Heiko; Wielsch, Natalie; Irmisch, Sandra; Ramasamy, Srinivasan; Gershenzon, Jonathan; Heckel, David G.; Köllner, Tobias G.

    2016-01-01

    Sesquiterpenes play important roles in insect communication, for example as pheromones. However, no sesquiterpene synthases, the enzymes involved in construction of the basic carbon skeleton, have been identified in insects to date. We investigated the biosynthesis of the sesquiterpene (6R,7S)-himachala-9,11-diene in the crucifer flea beetle Phyllotreta striolata, a compound previously identified as a male-produced aggregation pheromone in several Phyllotreta species. A (6R,7S)-himachala-9,11-diene–producing sesquiterpene synthase activity was detected in crude beetle protein extracts, but only when (Z,E)-farnesyl diphosphate [(Z,E)-FPP] was offered as a substrate. No sequences resembling sesquiterpene synthases from plants, fungi, or bacteria were found in the P. striolata transcriptome, but we identified nine divergent putative trans-isoprenyl diphosphate synthase (trans-IDS) transcripts. Four of these putative trans-IDSs exhibited terpene synthase (TPS) activity when heterologously expressed. Recombinant PsTPS1 converted (Z,E)-FPP to (6R,7S)-himachala-9,11-diene and other sesquiterpenes observed in beetle extracts. RNAi-mediated knockdown of PsTPS1 mRNA in P. striolata males led to reduced emission of aggregation pheromone, confirming a significant role of PsTPS1 in pheromone biosynthesis. Two expressed enzymes showed genuine IDS activity, with PsIDS1 synthesizing (E,E)-FPP, whereas PsIDS3 produced neryl diphosphate, (Z,Z)-FPP, and (Z,E)-FPP. In a phylogenetic analysis, the PsTPS enzymes and PsIDS3 were clearly separated from a clade of known coleopteran trans-IDS enzymes including PsIDS1 and PsIDS2. However, the exon–intron structures of IDS and TPS genes in P. striolata are conserved, suggesting that this TPS gene family evolved from trans-IDS ancestors. PMID:26936952

  12. Regulation of expression, activity and localization of fungal chitin synthases

    PubMed Central

    Rogg, Luise E.; Fortwendel, Jarrod R.; Juvvadi, Praveen R.; Steinbach, William J.

    2013-01-01

    The fungal cell wall represents an attractive target for pharmacologic inhibition, as many of the components are fungal-specific. Though targeted inhibition of β-glucan synthesis is effective treatment for certain fungal infections, the ability of the cell wall to dynamically compensate via the cell wall integrity pathway may limit overall efficacy. To date, chitin synthesis inhibitors have not been successfully deployed in the clinical setting. Fungal chitin synthesis is a complex and highly regulated process. Regulation of chitin synthesis occurs on multiple levels, thus targeting of these regulatory pathways may represent an exciting alternative approach. A variety of signaling pathways have been implicated in chitin synthase regulation, at both transcriptional and post-transcriptional levels. Recent research suggests that localization of chitin synthases likely represents a major regulatory mechanism. However, much of the regulatory machinery is not necessarily shared among different chitin synthases. Thus, an in depth understanding of the precise roles of each protein in cell wall maintenance and repair will be essential to identifying the most likely therapeutic targets. PMID:21526913

  13. Physiological Aldosterone Concentrations Are Associated with Alterations of Lipid Metabolism: Observations from the General Population.

    PubMed

    Hannich, M; Wallaschofski, H; Nauck, M; Reincke, M; Adolf, C; Völzke, H; Rettig, R; Hannemann, A

    2018-01-01

    Aldosterone and high-density lipoprotein cholesterol (HDL-C) are involved in many pathophysiological processes that contribute to the development of cardiovascular diseases. Previously, associations between the concentrations of aldosterone and certain components of the lipid metabolism in the peripheral circulation were suggested, but data from the general population is sparse. We therefore aimed to assess the associations between aldosterone and HDL-C, low-density lipoprotein cholesterol (LDL-C), total cholesterol, triglycerides, or non-HDL-C in the general adult population. Data from 793 men and 938 women aged 25-85 years who participated in the first follow-up of the Study of Health in Pomerania were obtained. The associations of aldosterone with serum lipid concentrations were assessed in multivariable linear regression models adjusted for sex, age, body mass index (BMI), estimated glomerular filtration rate (eGFR), and HbA1c. The linear regression models showed statistically significant positive associations of aldosterone with LDL-C ( β -coefficient = 0.022, standard error = 0.010, p = 0.03) and non-HDL-C ( β -coefficient = 0.023, standard error = 0.009, p = 0.01) as well as an inverse association of aldosterone with HDL-C ( β -coefficient = -0.022, standard error = 0.011, p = 0.04). The present data show that plasma aldosterone is positively associated with LDL-C and non-HDL-C and inversely associated with HDL-C in the general population. Our data thus suggests that aldosterone concentrations within the physiological range may be related to alterations of lipid metabolism.

  14. Expression of Allene Oxide Synthase Determines Defense Gene Activation in Tomato1

    PubMed Central

    Sivasankar, Sobhana; Sheldrick, Bay; Rothstein, Steven J.

    2000-01-01

    Allene oxide synthase (AOS; hydroperoxide dehydratase; EC 4.2.1.92) catalyzes the first step in the biosynthesis of jasmonic acid from lipoxygenase-derived hydroperoxides of free fatty acids. Using the AOS cDNA from tomato (Lycopersicon esculentum), in which the role of jasmonic acid in wound-induced defense gene activation has been best described, we examined the kinetics of AOS induction in response to wounding and elicitors, in parallel with that of the wound-inducible PIN II (proteinase inhibitor II) gene. AOS was induced in leaves by wounding, systemin, 12-oxophytodienoic acid, and methyl jasmonate. The levels of AOS mRNA started declining by 4 h after induction, whereas the levels of PIN II mRNA continued to increase up to 20 h after induction. Salicylic acid inhibited AOS and PIN II expression, and the addition of 12-oxophytodienoic acid or methyl jasmonate did not prevent the inhibition of PIN II expression in the presence of salicylic acid. Ethylene induced the expression of AOS, but the presence of ethylene alone did not produce an optimal induction of PIN II. The addition of silver thiosulfate, an ethylene action inhibitor, prevented the wound-induced expression of both AOS and PIN II. Products of hydroperoxide lyase affected neither AOS nor PIN II, but induced expression of prosystemin. Based on these results, we propose an updated model for defense gene activation in tomato. PMID:10759530

  15. Sequence of a cDNA and expression of the gene encoding a putative epidermal chitin synthase of Manduca sexta.

    PubMed

    Zhu, Yu-Cheng; Specht, Charles A; Dittmer, Neal T; Muthukrishnan, Subbaratnam; Kanost, Michael R; Kramer, Karl J

    2002-11-01

    Glycosyltransferases are enzymes that synthesize oligosaccharides, polysaccharides and glycoconjugates. One type of glycosyltransferase is chitin synthase, a very important enzyme in biology, which is utilized by insects, fungi, and other invertebrates to produce chitin, a polysaccharide of beta-1,4-linked N-acetylglucosamine. Chitin is an important component of the insect's exoskeletal cuticle and gut lining. To identify and characterize a chitin synthase gene of the tobacco hornworm, Manduca sexta, degenerate primers were designed from two highly conserved regions in fungal and nematode chitin synthase protein sequences and then used to amplify a similar region from Manduca cDNA. A full-length cDNA of 5152 nucleotides was assembled for the putative Manduca chitin synthase gene, MsCHS1, and sequencing of genomic DNA verified the contiguity of the sequence. The MsCHS1 cDNA has an ORF of 4692 nucleotides that encodes a transmembrane protein of 1564 amino acid residues with a mass of approximately 179 kDa (GenBank no. AY062175). It is most similar, over its entire length of protein sequence, to putative chitin synthases from other insects and nematodes, with 68% identity to enzymes from both the blow fly, Lucilia cuprina, and the fruit fly, Drosophila melanogaster. The similarity with fungal chitin synthases is restricted to the putative catalytic domain, and the MsCHS1 protein has, at equivalent positions, several amino acids that are essential for activity as revealed by mutagenesis of the fungal enzymes. A 5.3-kb transcript of MsCHS1 was identified by northern blot hybridization of RNA from larval epidermis, suggesting that the enzyme functions to make chitin deposited in the cuticle. Further examination by RT-PCR showed that MsCHS1 expression is regulated in the epidermis, with the amount of transcript increasing during phases of cuticle deposition.

  16. Alpha-tryptophan synthase of Isatis tinctoria: gene cloning and expression.

    PubMed

    Salvini, M; Boccardi, T M; Sani, E; Bernardi, R; Tozzi, S; Pugliesi, C; Durante, M

    2008-07-01

    Indole producing reaction is a crux in the regulation of metabolite flow through the pathways and the coordination of primary and secondary product biosynthesis in plants. Indole is yielded transiently from indole-3-glycerol phosphate and immediately condensed with serine to give tryptophan, by the enzyme tryptophan synthase (TS). There is evidence that plant TS, like the bacterial complex, functions as an alpha beta heteromer. In few species, e.g. maize, are known enzymes, related with the TS alpha-subunit (TSA), able to catalyse reaction producing indole, which is free to enter the secondary metabolite pathways. In this contest, we searched for TSA and TSA related genes in Isatis tinctoria, a species producing the natural blue dye indigo. The It-TSA cDNA and the full-length exons/introns genomic region were isolated. The phylogenetic analysis indicates that It-TSA is more closely related to Arabidopsis thaliana At-T14E10.210 TSA (95.7% identity at the amino acid level) with respect to A. thaliana At-T10P11.11 TSA1-like (63%), Zea mays indole-3-glycerol phosphate lyase (54%), Z. mays TSA (53%), and Z. mays indole synthase (50%). The It-TSA cDNA was also able to complement an Escherichia coli trpA mutant. To examine the involvement of It-TSA in the biosynthesis of secondary metabolism compounds, It-TSA expression was tested in seedling grown under different light conditions. Semi-quantitative RT-PCR showed an increase in the steady-state level of It-TSA mRNA, paralleled by an increase of indigo and its precursor isatan B. Our results appear to indicate an involvement for It-TSA in indigo precursor synthesis and/or tryptophan biosynthesis.

  17. Does continuous positive airway pressure reduce aldosterone levels in patients with obstructive sleep apnea?

    PubMed

    Yang, Si-Jiu; Jiang, Xing-Tang; Zhang, Xiao-Bin; Yin, Xiao-Wen; Deng, Wei-Xian

    2016-09-01

    Aldosterone is associated with the development of obstructive sleep apnea (OSA) and cardiovascular diseases. Continuous positive airway pressure (CPAP) is an effective treatment for OSA, but the impact of CPAP therapy on aldosterone levels in patients with OSA remains unclear. To address this issue, a meta-analysis was conducted to evaluate the effects of CPAP therapy on serum aldosterone levels in OSA. Two reviewers independently searched PubMed, Cochrane library, Embase, and Web of Science before March 2015. Information on characteristics of subjects, study design, and pre- and post-CPAP treatment of serum aldosterone was extracted for analysis. Standardized mean difference (SMD) was calculated to estimate the treatment effects of CPAP therapy. A total of 5 studies involving 329 patients were pooled into this meta-analysis, including 3 observational studies and 2 randomized controlled studies. Results indicated significantly decreased aldosterone levels after CPAP therapy (SMD = -0.236, 95 % confidence interval (CI) = -0.45 to -0.02, z = 2.12, p = 0.034). This meta-analysis suggested that CPAP therapy was associated with a decrease in serum aldosterone in patients with OSA. Further large-scale, well-designed interventional investigations are needed to clarify this issue.

  18. The unique response of renin and aldosterone to dietary sodium intervention in sodium sensitivity.

    PubMed

    Shin, Sung Joon; Lim, ChiYeon; Oh, Sang Woo; Rhee, Moo-Yong

    2014-06-01

    Sodium sensitivity (SS) is a phenomenon in which significant changes in blood pressure (BP) are observed based on sodium intake. The renin-angiotensin-aldosterone system plays a critical role in sodium handling and hypertension. We identified the specific responses of renin and aldosterone based on dietary sodium intake and revealed the relationship between these hormonal changes and dietary sodium intake in patients with SS. In total, 61 subjects were available to analyze full data including plasma renin activity (PRA) and aldosterone. Participants were given a low-sodium DASH diet (LSD) for 7 days and a high-sodium DASH diet (HSD) for the following 7 days. SS was found in five (14.71%) in normotensives, and 14 (51.85%) in hypertensives. In sodium-resistant (SR) subjects, both PRA and aldosterone decreased significantly after consuming HSD. Moreover, a significant correlation was observed between PRA and aldosterone in SR subjects. In contrast, only hypertensive subjects showed a marked fall in PRA after consuming HSD (1.299 ± 0.904 vs. 0.593 ± 0.479) among SS subjects. This study demonstrated the different responses of renin and aldosterone in SS and SR subjects based on dietary sodium intake whether or not they had hypertension. © The Author(s) 2014.

  19. Aldosterone, Renin, and Diabetes Mellitus in African Americans: The Jackson Heart Study.

    PubMed

    Joseph, Joshua J; Echouffo-Tcheugui, Justin B; Kalyani, Rita R; Yeh, Hsin-Chieh; Bertoni, Alain G; Effoe, Valery S; Casanova, Ramon; Sims, Mario; Correa, Adolfo; Wu, Wen-Chih; Wand, Gary S; Golden, Sherita H

    2016-04-01

    Previous research has suggested that activation of the renin-angiotensin-aldosterone system may promote insulin resistance and β-cell dysfunction, but the association with incident diabetes in African Americans is unknown. We examined the association of aldosterone and renin with insulin resistance, β-cell function, and incident diabetes in a large African American cohort. The Jackson Heart Study is a prospective study of the development and progression of cardiovascular disease in African Americans. Participants were recruited from the tricounty area of metropolitan Jackson, Mississippi. A total of 5301 African American adults, aged 21–94 years, were assessed at baseline and through 12 years of follow-up. Data on aldosterone, renin, and risk factors were collected at baseline (2000–2004). Diabetes (fasting glucose ≥ 126 mg/dL, physician diagnosis, use of diabetes drugs, or glycated hemoglobin ≥ 6.5%) was assessed at baseline and through 12 years of follow-up. Participants were excluded for missing data on baseline covariates or diabetes follow-up. Cox regression was used to estimate hazard ratios (HR) for incident diabetes using sequential modeling adjusting for age, sex, education, occupation, systolic blood pressure, current smoking, physical activity, dietary intake, and body mass index. Aldosterone, renin, and diabetes risk factors were measured. Outcomes included the homeostatic model assessment of insulin resistance (HOMA-IR) and incident diabetes. Among 3234 participants over a median of 8.0 years of follow-up, there were 554 cases of incident diabetes. Every 1% increase in log-transformed aldosterone was associated with a 0.18% higher log-transformed HOMA-IR in cross-sectional analyses of nondiabetic participants (P < .001). Log-transformed aldosterone and renin levels in the fifth vs first quintile were associated with a 78% (HR 1.78, 95% confidence interval 1.35–2.34) and 35% (HR 1.35, 95% confidence interval 1.06–1.72) increase in diabetes

  20. Influence of aldosterone and salt or ouabain in a10 rat aorta smooth muscle cells.

    PubMed

    Schwerdt, Gerald; Frisch, Annett; Mildenberger, Sigrid; Hilgenfeld, Tim; Grossmann, Claudia; Gekle, Michael

    2012-01-01

    It is currently under debate whether aldosterone is able to induce fibrosis or whether it acts only as a cofactor under pathological conditions, e.g. as an elevated salt (NaCl) load. We tested the interaction of 10 nM aldosterone, 15 mM NaCl and 1 μM ouabain using rat aorta smooth muscle cells (A10) with respect to the following parameters: necrosis, apoptosis, glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase activity, glutathione (GSH) content, collagen and fibronectin homeostasis and intracellular calcium distribution. Necrosis rates were increased after 48 h of incubation with aldosterone, salt or ouabain and in the combination of aldosterone and salt or ouabain. Apoptosis rates were decreased. A reduced defense capacity against oxidative stress was mirrored in the decreased G6PD activity and GSH content. Collagen III or fibronectin synthesis rates were unchanged, but gelatinase activity was increased resulting in a decreased media collagen III and fibronectin content. Calcium stores were increased by aldosterone in combination with ouabain. Aldosterone and salt per se can lead to cell injury that is aggravated in combination or with cardiotonic steroids. In cooperation with other vascular cells, this can generate a permissive milieu enabling aldosterone or salt to promote more extensive vascular injury. Copyright © 2012 S. Karger AG, Basel.

  1. Hypohydration and Heat Acclimation: Plasma Renin and Aldosterone during Exercise,

    DTIC Science & Technology

    1983-01-01

    vasoconstriction in heat-stressed men: role of McGraw-Hill, 1964, p. 419-423. renin - angiotensin system . J. AppL PhysioL: Respirat. Environ. 13. LINDQUIST, E...AL.A137 365 HYPOHYDRATION AND HEAT ACCLIMATION: PLASMA RENIN AND I/ ALDOSTERONE DURING EXERCISE(U) ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE...heat acclimation:plasma renin dependent not only on the mode of exercise but also the and aldosterone during exercise. J. Appl. Physiol.: Respirat

  2. Control of Plasma Aldosterone in Mammals.

    ERIC Educational Resources Information Center

    Reinking, Larry N.

    1980-01-01

    Presents a discussion of the potential controls of plasma aldosterone levels in humans or mammals. A diagram is given which summarizes the controls. Topics for discussion, that are prompted by the diagram, are given at the end of the paper. (Author/SA)

  3. Effects of acrolein on aldosterone release from zona glomerulosa cells in male rats.

    PubMed

    Wang, Kai-Lee; Huang, Wen-Ching; Chou, Jou-Chun; Weng, Ting-Chun; Hu, Sindy; Lieu, Fu-Kong; Lai, Wei-Ho; Idova, Galina; Wang, Paulus S; Wang, Shyi-Wu

    2016-07-01

    A positive correlation between smoking and hypertension has been well established. Acrolein is a major toxic volatile compound found in cigarette smoke. Human exposure to low levels of acrolein is unavoidable due to its production in daily activities, such as smoke from industrial, hot oil cooking vapors, and exhaust fumes from vehicles. The toxicity and the action mechanism of acrolein to induce apoptosis have been extensively studied, but the effects of acrolein on hypertension are still unknown. The present study aimed to examine the effects of acrolein on aldosterone release both in vivo and in vitro. Male rats were divided into three groups, and intraperitoneally injected with normal saline, or acrolein (2mg/kg) for 1 (group A-1) or 3 (group A-3) days, respectively. After sacrificing, rat blood samples were obtained to measure plasma aldosterone and angiotensin II (Ang II) levels. Zona glomerulosa (ZG) cells were prepared from rat adrenal cortex, and were incubated with or without stimulants. We found that the serum aldosterone was increased by 1.2-fold (p<0.05) in A-3 group as compared to control group. Basal aldosterone release from ZG cells in A-3 group was also increased significantly. Moreover, acrolein enhanced the stimulatory effects of Ang II and 8-bromo-cyclic AMP on aldosterone secretion from ZG cells prepared in both A-1 and A-3 groups. Furthermore, the enzyme activity of P450scc, the rate-limiting step of aldosterone synthesis, was elevated after acrolein injection. Plasma level of Ang II was increased in both A-1 and A-3 groups. These results suggested that acrolein exposure increased aldosterone production, at least in part, through elevating the level of plasma Ang II and stimulating steroidogenesis pathways. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Diagnostic value of ACTH stimulation test in determining the subtypes of primary aldosteronism.

    PubMed

    Jiang, Yiran; Zhang, Cui; Wang, Weiqing; Su, Tingwei; Zhou, Weiwei; Jiang, Lei; Zhu, Wei; Xie, Jing; Ning, Guang

    2015-05-01

    Adrenal venous sampling is recommended as the golden standard for subtyping primary aldosteronism (PA). However, it is invasive and inconvenient, and seeking a better way to make differential diagnosis of PA is necessary. The objective of the study was to evaluate the diagnostic value of ACTH stimulation test under 1 mg dexamethasone suppression test (DST) in determining the subtypes of PA. Ninety-five patients with PA confirmed by saline infusion test were included in this study. According to adrenal venous sampling and histopathology, 39 patients were diagnosed as bilateral adrenal hyperplasia (BAH), 37 as aldosterone-producing adenoma (APA), and 19 as unilateral adrenal hyperplasia (UAH). An ACTH stimulation test under 1 mg DST was performed in all patients. Plasma aldosterone and cortisol levels were measured every 30 minutes until 120 minutes after the iv injection of 50 IU ACTH. During the ACTH stimulation test, aldosterone levels in APA and UAH were similar (P > .05) but higher than those in BAH (P < .001). Furthermore, stimulated aldosterone levels of unilateral PA (APA and UAH) were significantly higher than bilateral PA (BAH) (P < .001). Receiver-operated characteristics curve analyses showed the aldosterone after ACTH stimulation was effective for distinguishing between unilateral PA and bilateral PA. The diagnostic accuracy was highest at 120 minutes after ACTH stimulation, and the optimal cutoff value of the aldosterone was 77.90 ng/dL, with a sensitivity of 76.8%, a specificity of 87.2%, a positive predictive value of 89.6%, and a negative predictive value of 72.3%. The ACTH stimulation test under 1 mg DST is useful to determine the subtypes of PA, especially in unilateral and bilateral PA, and may guide further treatment in PA patients.

  5. [Aldosterone response to various stimuli in hyperthyroidism: in vivo and in vitro studies].

    PubMed

    Kigoshi, T; Kaneko, M; Nakano, S; Azukizawa, S; Uchida, K; Morimoto, S

    1993-06-20

    Responses of plasma aldosterone (PA) to alpha-ACTH-(1-24) (250 micrograms, im) injection and graded angiotensin II (AII) infusions (2, 4 and 8ng/kg/min for 30 min at each dose) on a constant sodium intake (170mEq daily) were assessed in 17 patients with Basedow's disease and 13 age-matched normal subjects. Aldosterone production in response to ACTH, AII and potassium in adrenal zona glomerulosa cells from L-thyroxine-induced hyperthyroid rats (H-rats) were also examined. Basal levels of plasma renin activity (PRA) and urinary aldosterone excretion were significantly higher (p < 0.01 and p < 0.05, respectively) in the patients with Basedow's disease than in the normal subjects, whereas basal PA level was similar in the two groups. The ACTH injection induced similar increases in plasma cortisol, plasma 18-hydroxycorticosterone (18-OHB) and PA in the two groups. The graded AII infusions also produced increases in plasma 18-OHB and PA in the two groups. Responses of these two corticosteroids to AII were, however, significantly lower (p < 0.05) in the patients with Basedow's disease than in the normal subjects. In the experimental animal study, basal PRA levels and the adrenal glomerulosa cell count/adrenal were significantly higher (p < 0.05) in the H-rats than in the control rats, whereas basal PA levels were similar in the two groups. Aldosterone production in response to AII, ACTH, and potassium increased in a dose-dependent manner in the two groups. Responses of aldosterone production to AII were, however, significantly lower (p < 0.05) in the H-rats than in the control rats. These results suggest that the impaired responsiveness of adrenal zona glomerulosa cells to AII, as well as an increased metabolic clearance rate of aldosterone, may be involved in the abnormal aldosterone metabolism in hyperthyroidism.

  6. Aldosterone signaling regulates the over-expression of claudin-4 and -8 at the distal nephron from type 1 diabetic rats.

    PubMed

    Molina-Jijón, Eduardo; Rodríguez-Muñoz, Rafael; González-Ramírez, Ricardo; Namorado-Tónix, Carmen; Pedraza-Chaverri, José; Reyes, Jose L

    2017-01-01

    Hyperglycemia in diabetes alters tight junction (TJ) proteins in the kidney. We evaluated the participation of aldosterone (ALD), and the effect of spironolactone (SPL), a mineralocorticoid receptor antagonist, on the expressions of claudin-2, -4, -5 and -8, and occludin in glomeruli, proximal and distal tubules isolated from diabetic rats. Type 1 diabetes was induced in female Wistar rats by a single tail vein injection of streptozotocin (STZ), and SPL was administrated daily by gavage, from days 3-21. Twenty-one days after STZ injection the rats were sacrificed. In diabetic rats, the serum ALD levels were increased, and SPL-treatment did not have effect on these levels or in hyperglycemia, however, proteinuria decreased in SPL-treated diabetic rats. Glomerular damage, evaluated by nephrin and Wilm's tumor 1 (WT1) protein expressions, and proximal tubular damage, evaluated by kidney injury molecule 1 (Kim-1) and heat shock protein 72 kDa (Hsp72) expressions, were ameliorated by SPL. Also, SPL prevented decrement in claudin-5 in glomeruli, and claudin-2 and occludin in proximal tubules by decreasing oxidative stress, evaluated by superoxide anion (O2●-) production, and oxidative stress markers. In distal tubules, SPL ameliorated increase in mRNA, protein expression, and phosphorylation in threonine residues of claudin-4 and -8, through a serum and glucocorticoid-induced kinase 1 (SGK1), and with-no-lysine kinase 4 (WNK4) signaling pathway. In conclusion, this is the first study that demonstrates that ALD modulates the expression of renal TJ proteins in diabetes, and that the blockade of its actions with SPL, may be a promising therapeutic strategy to prevent alterations of TJ proteins in diabetic nephropathy.

  7. Re-evaluation of the fludrocortisone test: duration, NaCl supplementation and cut-off limits for aldosterone.

    PubMed

    Westerdahl, Christina; Bergenfelz, Anders; Larsson, Johanna; Nerbrand, Christina; Valdemarsson, Stig; Wihl, Anders; Isaksson, Anders

    2009-01-01

    Primary aldosteronism (PA) is the most common form of secondary hypertension. Thus, the aims of this study were: (1) to clarify whether the fludrocortisone suppression test (FST), which confirms autonomous aldosterone secretion, is reliable when carried out during a shorter period of time and (2) to confirm the importance of NaCl supplementation. The cut-off limits already obtained for aldosterone in healthy subjects during the FST were applied in hypertensive patients with a high aldosterone to renin ratio (ARR). The healthy subjects were allocated to three groups. Fludrocortisone was administered 4 times daily over 4 days and sodium chloride was supplemented in 3 different doses. The result was applied in 24 hypertensive patients, in 24 healthy subjects (10 women (23-38 years old) and 14 men (23-58 years old)) and in 24 patients with hypertension and high ARR (16 women (45-74 years old) and 8 men (56-73 years old)). Blood pressure, aldosterone, renin, potassium and sodium were measured. After three days of FST, there was a significant decrease in the serum level of aldosterone in the healthy subjects, regardless of high or low sodium chloride supplementation (p<0.001). The decrease in serum aldosterone was significantly less pronounced in patients with PA than in healthy subjects and hypertensive patients without PA (p<0.001). The 95th percentile of plasma aldosterone at the end of the test was 225 pmol/L. The FST can be shortened to 3 days and a daily 500 mg NaCl supplementation is sufficient. A cut-off value for aldosterone of 225 pmol/L after 4 days with FST is appropriate.

  8. Associations of aldosterone and renin concentrations with inflammation-the Study of Health in Pomerania and the German Conn's Registry.

    PubMed

    Grotevendt, A; Wallaschofski, H; Reincke, M; Adolf, C; Quinkler, M; Nauck, M; Hoffmann, W; Rettig, R; Hannemann, A

    2017-08-01

    Chronic inflammation is an age-independent and body mass index-independent contributor to the development of multi-morbidity. Alterations of the renin-angiotensin-aldosterone system are observed within the context of proinflammatory states. We assessed circulating aldosterone, renin, and inflammatory biomarker concentrations in healthy, normotensive subjects and patients with primary aldosteronism. We included 1177 normotensive individuals from the population-based Study of Health in Pomerania (first follow-up, Study of Health in Pomerania-1) and 103 primary aldosteronism patients from the German Conn's Registry. A 1:1 matching for sex, age, body mass index, smoking status, diabetes mellitus, and the estimated glomerular filtration rate was performed to determine whether primary aldosteronism patients exhibit higher inflammatory biomarker concentrations than normotensive controls. The associations of plasma aldosterone concentration or plasma renin concentration with circulating fibrinogen concentrations, white blood cell count, and high sensitive C-reactive protein concentrations in the normotensive sample were determined with multivariable linear and logistic regression analyses. 1:1 matched primary aldosteronism patients demonstrated significantly (p < 0.01) higher plasma aldosterone concentration (198 vs. 47 ng/l), lower plasma renin concentration (3.1 vs. 7.7 ng/l) and higher high sensitive C-reactive protein concentrations (1.5 vs. 1.0 mg/l) than normotensive controls. Within the normotensive cohort, plasma renin concentration but not plasma aldosterone concentration was positively associated with fibrinogen concentrations and white blood cell count. Further, a J-shaped association between plasma renin concentration and high sensitive C-reactive protein concentrations was detected. High plasma aldosterone concentration in a primary aldosteronism cohort and high plasma renin concentration in normotensive subjects are associated with increased

  9. Rapid effects of aldosterone in primary cultures of cardiomyocytes - do they suggest the existence of a membrane-bound receptor?

    PubMed

    Araujo, Carolina Morais; Hermidorff, Milla Marques; Amancio, Gabriela de Cassia Sousa; Lemos, Denise da Silveira; Silva, Marcelo Estáquio; de Assis, Leonardo Vinícius Monteiro; Isoldi, Mauro César

    2016-10-01

    Aldosterone acts on its target tissue through a classical mechanism or through the rapid pathway through a putative membrane-bound receptor. Our goal here was to better understand the molecular and biochemical rapid mechanisms responsible for aldosterone-induced cardiomyocyte hypertrophy. We have evaluated the hypertrophic process through the levels of ANP, which was confirmed by the analysis of the superficial area of cardiomyocytes. Aldosterone increased the levels of ANP and the cellular area of the cardiomyocytes; spironolactone reduced the aldosterone-increased ANP level and cellular area of cardiomyocytes. Aldosterone or spironolactone alone did not increase the level of cyclic 3',5'-adenosine monophosphate (cAMP), but aldosterone plus spironolactone led to increased cAMP level; the treatment with aldosterone + spironolactone + BAPTA-AM reduced the levels of cAMP. These data suggest that aldosterone-induced cAMP increase is independent of mineralocorticoid receptor (MR) and dependent on Ca(2+). Next, we have evaluated the role of A-kinase anchor proteins (AKAP) in the aldosterone-induced hypertrophic response. We have found that St-Ht31 (AKAP inhibitor) reduced the increased level of ANP which was induced by aldosterone; in addition, we have found an increase on protein kinase C (PKC) and extracellular signal-regulated kinase 5 (ERK5) activity when cells were treated with aldosterone alone, spironolactone alone and with a combination of both. Our data suggest that PKC could be responsible for ERK5 aldosterone-induced phosphorylation. Our study suggests that the aldosterone through its rapid effects promotes a hypertrophic response in cardiomyocytes that is controlled by an AKAP, being dependent on ERK5 and PKC, but not on cAMP/cAMP-dependent protein kinase signaling pathways. Lastly, we provide evidence that the targeting of AKAPs could be relevant in patients with aldosterone-induced cardiac hypertrophy and heart failure.

  10. Endothelial mineralocorticoid receptor activation mediates endothelial dysfunction in diet-induced obesity.

    PubMed

    Schäfer, Nicola; Lohmann, Christine; Winnik, Stephan; van Tits, Lambertus J; Miranda, Melroy X; Vergopoulos, Athanasios; Ruschitzka, Frank; Nussberger, Jürg; Berger, Stefan; Lüscher, Thomas F; Verrey, François; Matter, Christian M

    2013-12-01

    Aldosterone plays a crucial role in cardiovascular disease. 'Systemic' inhibition of its mineralocorticoid receptor (MR) decreases atherosclerosis by reducing inflammation and oxidative stress. Obesity, an important cardiovascular risk factor, is an inflammatory disease associated with increased plasma aldosterone levels. We have investigated the role of the 'endothelial' MR in obesity-induced endothelial dysfunction, the earliest stage in atherogenesis. C57BL/6 mice were exposed to a normal chow diet (ND) or a high-fat diet (HFD) alone or in combination with the MR antagonist eplerenone (200 mg/kg/day) for 14 weeks. Diet-induced obesity impaired endothelium-dependent relaxation in response to acetylcholine, whereas eplerenone treatment of obese mice prevented this. Expression analyses in aortic endothelial cells isolated from these mice revealed that eplerenone attenuated expression of pro-oxidative NADPH oxidase (subunits p22phox, p40phox) and increased expression of antioxidative genes (glutathione peroxidase-1, superoxide dismutase-1 and -3) in obesity. Eplerenone did not affect obesity-induced upregulation of cyclooxygenase (COX)-1 or prostacyclin synthase. Endothelial-specific MR deletion prevented endothelial dysfunction in obese (exhibiting high 'endogenous' aldosterone) and in 'exogenous' aldosterone-infused lean mice. Pre-incubation of aortic rings from aldosterone-treated animals with the COX-inhibitor indomethacin restored endothelial function. Exogenous aldosterone administration induced endothelial expression of p22phox in the presence, but not in the absence of the endothelial MR. Obesity-induced endothelial dysfunction depends on the 'endothelial' MR and is mediated by an imbalance of oxidative stress-modulating mechanisms. Therefore, MR antagonists may represent an attractive therapeutic strategy in the increasing population of obese patients to decrease vascular dysfunction and subsequent atherosclerotic complications.

  11. Sucrose Synthase Expression during Cold Acclimation in Wheat 1

    PubMed Central

    Crespi, Martin D.; Zabaleta, Eduardo J.; Pontis, Horacio G.; Salerno, Graciela L.

    1991-01-01

    When wheat (Triticum aestivum) seedlings are exposed to a cold temperature (2-4°C) above 0°C, sucrose accumulates and sucrose synthase activity increases. The effect of a cold period on the level of sucrose synthase (SS) was investigated. Using antibodies against wheat germ SS, Western blots studies showed that the amount of the SS peptide increased during 14 days in the cold, when plants were moved from 23°C to 4°C. The level of SS diminished when plants were moved back to 23°C. Northern blots of poly(A)+ RNA, confirmed a five- to sixfold induction of SS in wheat leaves during cold acclimation. These results indicate that SS is involved in the plant response to a chilling stress. ImagesFigure 1Figure 2Figure 3 PMID:16668270

  12. The Renin-Aldosterone axis in kidney transplant recipients and its association with allograft function and structure

    PubMed Central

    Issa, Naim; Ortiz, Fernando; Reule, Scott; Kukla, Aleksandra; Kasiske, Bertram; Mauer, Michael; Jackson, Scott; Matas, Arthur J.; Ibrahim, Hassan N.

    2013-01-01

    The level of the renin-angiotensin-aldosterone system (RAAS) activity in kidney transplant recipients has not been extensively studied or serially profiled. To describe this axis and to determine its association with GFR change, interstitial expansion and end-stage renal disease (ESRD) we measured plasma renin activity (PRA) and plasma aldosterone levels annually for 5 years in 153 kidney transplant recipients randomly assigned to losartan or placebo. PRA and plasma aldosterone levels were in the normal range at all times and did not vary by immunosuppression regimen. Those on losartan exhibited higher PRA but similar plasma aldosterone levels. Neither baseline nor serial PRA or plasma aldosterone levels were associated with GFR decline, proteinuria or interstitial expansion. Losartan use, [HR 0.48 (95% CI 0.21–1.0), insignificant], and Caucasian donor, [HR 0.18 (95% CI 0.07–0.4), significant] were associated with less doubling of serum creatinine, death or ESRD. Hypertension, less than 3 HLA-matches, the combination of tacrolimus-rapamycin and acute rejection were associated with more events. Neither PRA nor plasma aldosterone levels were independently associated with this outcome. Higher serial plasma aldosterone levels were associated, however, with a significantly higher risk of ESRD, [HR 1.01 (95% CI 1.00–1.02)]. Thus, systemic RAAS is not overly activated in kidney transplant recipients but this may not reflect the intrarenal system. Importantly, plasma aldosterone levels may be associated with more ESRD. PMID:23965522

  13. Association of Post-Saline Load Plasma Aldosterone Levels With Left Ventricular Hypertrophy in Primary Hypertension.

    PubMed

    Catena, Cristiana; Verheyen, Nicolas D; Url-Michitsch, Marion; Kraigher-Krainer, Elisabeth; Colussi, GianLuca; Pilz, Stefan; Tomaschitz, Andreas; Pieske, Burkert; Sechi, Leonardo A

    2016-03-01

    Left ventricular hypertrophy (LVH) is an independent risk factor for cardiovascular morbidity in hypertension. Current evidence suggests a contribution to LVH of plasma aldosterone levels that are inappropriately elevated for the salt status. The aim of this study was to investigate whether inappropriate modulation of aldosterone production by a saline load is associated with left ventricular (LV) mass in hypertensive patients. In 90 hypertensive patients free of clinically relevant cardiovascular complications in whom secondary forms of hypertension were ruled out, we performed a standard intravenous saline load (0.9% NaCl, 2 l in 4 hours) with measurement of plasma aldosterone and active renin at baseline and end of infusion. Bi-dimensional echocardiography was performed for the assessment of cardiac morphology and function. LVH was present in 19% of patients who had significantly worse renal function and higher body mass, blood pressure, and plasma aldosterone levels measured both at baseline and after the saline load than patients without LVH. LV mass was directly related to age, body mass, systolic blood pressure, duration of hypertension, baseline, and post-saline load plasma aldosterone levels and inversely to glomerular filtration. Multivariate regression analysis showed independent correlation of LV mass with body mass, systolic blood pressure, and plasma aldosterone levels measured after intravenous saline load, but not at baseline. In patients with hypertension, aldosterone levels measured after intravenous saline load are related to LV mass independent of age, body mass, and blood pressure, suggesting that limited ability of salt to modulate aldosterone production could contribute to LVH. © American Journal of Hypertension, Ltd 2015. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. [Expression and antagonist role of endothelin and nitric oxide synthase in atherosclerotic plaque].

    PubMed

    Song, L; Wang, D; Wang, T

    1997-02-01

    To study the pathogenetic mechanism of atherosclerotic plaque, the action of mediation and antagonism of endothelin (ET) and nitric oxide synthase (NOS) was investigated. In situ hybridization, RT-PCR on endothelin and NOS, cytochemistry on NOS were measured using the rabbit atherosclerosis model and cultured vascular smooth muscle cells (VSMC) from normal rabbit. Transcription of endothelin mRNA increased and transcription of NOS mRNA decreased in astherosclerotic plaque: compared with normal aorta, expression of ET gene in plaque was increased by 1.2 times and the expression of NOS gene was decreased by 22.2%; cytochemistry combined with image pattern analysis showed that ET could inhibit NOS protien synthesis in VSMC; type A receptor antagonist of ET could inhibit the role of ET which causes a decrease of NOS protein in VSMC. The imbalance between NOS and ET, namely abnormal increase of ET and/or obvious decrease of NOS, is related to atherosclerotic plaque formation.

  15. Cloning, characterization, expression and comparative analysis of pig Golgi membrane sphingomyelin synthase 1.

    PubMed

    Guillén, Natalia; Navarro, María A; Surra, Joaquín C; Arnal, Carmen; Fernández-Juan, Marta; Cebrián-Pérez, Jose Alvaro; Osada, Jesús

    2007-02-15

    Pig sphingomyelin synthase 1 (SMS1) cDNA was cloned, characterized and compared to the human ortholog. Porcine protein consists of 413 amino acids and displays a 97% sequence identity with human protein. A phylogenic tree of proteins reveals that porcine SMS1 is more closely related to bovine and rodent proteins than to human. Analysis of protein mass was higher than the theoretical prediction based on amino acid sequence suggesting a kind of posttranslational modification. Quantitative representation of tissue distribution obtained by real-time RT-PCR showed that it was widely expressed although important variations in levels were obtained among organs. Thus, the cardiovascular system, especially the heart, showed the highest value of all the tissues studied. Regional differences of expression were observed in the central nervous system and intestinal tract. Analysis of the hepatic mRNA and protein expressions of SMS1 following turpentine treatment revealed a progressive decrease in the former paralleled by a decrease in the protein concentration. These findings indicate the variation in expression in the different tissues might suggest a different requirement of Golgi sphingomyelin for the specific function in each organ and a regulation of the enzyme in response to turpentine-induced hepatic injury.

  16. Use of plasma metanephrine to aid adrenal venous sampling in combined aldosterone and cortisol over-secretion.

    PubMed

    Goupil, Rémi; Wolley, Martin; Ungerer, Jacobus; McWhinney, Brett; Mukai, Kuniaki; Naruse, Mitsuhide; Gordon, Richard D; Stowasser, Michael

    2015-01-01

    In patients with primary aldosteronism (PA) undergoing adrenal venous sampling (AVS), cortisol levels are measured to assess lateralization of aldosterone overproduction. Concomitant adrenal autonomous cortisol and aldosterone secretion therefore have the potential to confound AVS results. We describe a case where metanephrine was measured during AVS to successfully circumvent this problem. A 55-year-old hypertensive male had raised plasma aldosterone/renin ratios and PA confirmed by fludrocortisone suppression testing. Failure of plasma cortisol to suppress overnight following dexamethasone and persistently suppressed corticotrophin were consistent with adrenal hypercortisolism. On AVS, comparison of adrenal and peripheral A/F ratios (left 5.7 vs peripheral 1.0; right 1.7 vs peripheral 1.1) suggested bilateral aldosterone production, with the left gland dominant but without contralateral suppression. However, using aldosterone/metanephrine ratios (left 9.7 vs peripheral 2.4; right 1.3 vs peripheral 2.5), aldosterone production lateralized to the left with good contralateral suppression. The patient underwent left laparoscopic adrenalectomy with peri-operative glucocorticoid supplementation to prevent adrenal insufficiency. Pathological examination revealed adrenal cortical adenomas producing both cortisol and aldosterone within a background of aldosterone-producing cell clusters. Hypertension improved and cured of PA and hypercortisolism were confirmed by negative post-operative fludrocortisone suppression and overnight 1 mg dexamethasone suppression testing. Routine dexamethasone suppression testing in patients with PA permits detection of concurrent hypercortisolism which can confound AVS results and cause unilateral PA to be misdiagnosed as bilateral with patients thereby denied potentially curative surgical treatment. In such patients, measurement of plasma metanephrine during AVS may overcome this issue. Simultaneous autonomous overproduction of cortisol

  17. Aldosterone mediates metastatic spread of renal cancer via the G protein-coupled estrogen receptor (GPER).

    PubMed

    Feldman, Ross D; Ding, Qingming; Hussain, Yasin; Limbird, Lee E; Pickering, J Geoffrey; Gros, Robert

    2016-06-01

    Although aldosterone is a known regulator of renal and cardiovascular function, its role as a regulator of cancer growth and spread has not been widely considered. This study tested the hypothesis that aldosterone regulates cancer cell growth/spread via G protein-coupled estrogen receptor (GPER) activation. In vitro in murine renal cortical adenocarcinoma (RENCA) cells, a widely used murine in vitro model for the study of renal cell adenocarcinoma, aldosterone increased RENCA cell proliferation to a maximum of 125 ± 3% of control at a concentration of 10 nM, an effect blocked by the GPER antagonist G15 or by GPER knockdown using short interfering (sh) RNA techniques. Further, aldosterone increased RENCA cell migration to a maximum of 170 ± 20% of control at a concentration of 100 nM, an effect also blocked by G15 or by GPER down-regulation. In vivo, after orthotopic RENCA cell renal transplantation, pulmonary tumor spread was inhibited by pharmacologic blockade of aldosterone effects with spironolactone (percentage of lung occupied by metastasis: control = 68 ± 13, spironolactone = 26 ± 8, P < 0.05) or inhibition of aldosterone synthesis with a high dietary salt diet (percentage of lung: control = 44 ± 6, high salt = 12 ± 3, P < 0.05), without reducing primary tumor size. Additionally, adrenalectomy significantly reduced the extent of pulmonary tumor spread, whereas aldosterone infusion recovered pulmonary metastatic spread toward baseline levels. Finally, inhibition of GPER either with the GPER antagonist G15 or by GPER knockdown comparably inhibited RENCA cell pulmonary metastatic cancer spread. Taken together, these findings provide strong evidence for aldosterone serving a causal role in renal cell cancer regulation via its GPER receptor; thus, antagonism of GPER represents a potential new target for treatment to reduce metastatic spread.-Feldman, R. D., Ding, Q., Hussain, Y., Limbird, L. E., Pickering, J. G., Gros, R. Aldosterone mediates metastatic

  18. Recombinant expression of a functional myo-inositol-1-phosphate synthase (MIPS) in Mycobacterium smegmatis.

    PubMed

    Huang, Xinyi; Hernick, Marcy

    2015-10-01

    Myo-inositol-1-phosphate synthase (MIPS, E.C. 5.5.1.4) catalyzes the first step in inositol production-the conversion of glucose-6-phosphate (Glc-6P) to myo-inositol-1-phosphate. While the three dimensional structure of MIPS from Mycobacterium tuberculosis has been solved, biochemical studies examining the in vitro activity have not been reported to date. Herein we report the in vitro activity of mycobacterial MIPS expressed in E. coli and Mycobacterium smegmatis. Recombinant expression in E. coli yields a soluble protein capable of binding the NAD(+) cofactor; however, it has no significant activity with the Glc-6P substrate. In contrast, recombinant expression in M. smegmatis mc(2)4517 yields a functionally active protein. Examination of structural data suggests that MtMIPS expressed in E. coli adopts a fold that is missing a key helix containing two critical (conserved) Lys side chains, which likely explains the inability of the E. coli expressed protein to bind and turnover the Glc-6P substrate. Recombinant expression in M. smegmatis may yield a protein that adopts a fold in which this key helix is formed enabling proper positioning of important side chains, thereby allowing for Glc-6P substrate binding and turnover. Detailed mechanistic studies may be feasible following optimization of the recombinant MIPS expression protocol in M. smegmatis.

  19. Aldosterone induces rapid sodium intake by a nongenomic mechanism in the nucleus tractus solitarius.

    PubMed

    Qiao, Hu; Hu, Bo; Zhou, Hong; Yan, Jianqun; Jia, Ru; Lu, Bo; Sun, Bo; Luo, Xiao; Fan, Yuanyuan; Wang, Nan

    2016-12-09

    The purpose of this study was to determine whether aldosterone has a rapid action in the nucleus tractus solitarius (NTS) that increases sodium intake, and to examine whether this effect of aldosterone, if present, is mediated by G protein-coupled estrogen receptor (GPER). Adult male Sprague-Dawley rats with a stainless-steel cannula in the NTS were used. Aldosterone was injected into the NTS at the doses of 1, 5, 10 and 20 ng 0.1 μl -1 . A rapid dose-related increase of 0.3 M NaCl intake was induced within 30 min and this increase was not suppressed by the mineralocorticoid receptor (MR) antagonist spironolactone (10 ng 0.1 μl -1 ). Water intake was not affected by aldosterone. The GPER agonist G-1 produced a parallel and significant increase in sodium intake, while pre-treatment with GPER antagonist G15 (10 ng 0.1 μl -1 ) blocked the G-1 or aldosterone-induced rapid sodium intake. In addition, sodium intake induced by sodium depletion or low-sodium diet fell within 30 min after injection into the NTS of the MR antagonist spironolactone, while G15 had no effect. Our results confirm previous reports, and support the hypothesis that aldosterone evokes rapid sodium intake through a non-genomic mechanism involving GPER in NTS.

  20. Generation and Functional Evaluation of Designer Monoterpene Synthases.

    PubMed

    Srividya, N; Lange, I; Lange, B M

    2016-01-01

    Monoterpene synthases are highly versatile enzymes that catalyze the first committed step in the pathways toward terpenoids, the structurally most diverse class of plant natural products. Recent advancements in our understanding of the reaction mechanism have enabled engineering approaches to develop mutant monoterpene synthases that produce specific monoterpenes. In this chapter, we are describing protocols to introduce targeted mutations, express mutant enzyme catalysts in heterologous hosts, and assess their catalytic properties. Mutant monoterpene synthases have the potential to contribute significantly to synthetic biology efforts aimed at producing larger amounts of commercially attractive monoterpenes. © 2016 Elsevier Inc. All rights reserved.

  1. Volatile emissions of scented Alstroemeria genotypes are dominated by terpenes, and a myrcene synthase gene is highly expressed in scented Alstroemeria flowers

    PubMed Central

    Aros, Danilo; Gonzalez, Veronica; Allemann, Rudolf K.; Müller, Carsten T.; Rosati, Carlo; Rogers, Hilary J.

    2012-01-01

    Native to South America, Alstroemeria flowers are known for their colourful tepals, and Alstroemeria hybrids are an important cut flower. However, in common with many commercial cut flowers, virtually all the commercial Alstroemeria hybrids are not scented. The cultivar ‘Sweet Laura’ is one of very few scented commercial Alstroemeria hybrids. Characterization of the volatile emission profile of these cut flowers revealed three major terpene compounds: (E)-caryophyllene, humulene (also known as α-caryophyllene), an ocimene-like compound, and several minor peaks, one of which was identified as myrcene. The profile is completely different from that of the parental scented species A. caryophyllaea. Volatile emission peaked at anthesis in both scented genotypes, coincident in cv. ‘Sweet Laura’ with the maximal expression of a putative terpene synthase gene AlstroTPS. This gene was preferentially expressed in floral tissues of both cv. ‘Sweet Laura’ and A. caryophyllaea. Characterization of the AlstroTPS gene structure from cv. ‘Sweet Laura’ placed it as a member of the class III terpene synthases, and the predicted 567 amino acid sequence placed it into the subfamily TPS-b. The conserved sequences R28(R)X8W and D321DXXD are the putative Mg2+-binding sites, and in vitro assay of AlstroTPS expressed in Escherichia coli revealed that the encoded enzyme possesses myrcene synthase activity, consistent with a role for AlstroTPS in scent production in Alstroemeria cv. ‘Sweet Laura’ flowers. PMID:22268153

  2. Intersubunit structure within heterodimers of medium-chain prenyl diphosphate synthases. Formation of a hybrid-type heptaprenyl diphosphate synthase.

    PubMed

    Koike-Takeshita, A; Koyama, T; Ogura, K

    1998-10-01

    Among prenyltransferases that catalyze the sequential condensation of isopentenyl diphosphate with allylic diphosphate to produce prenyl diphosphates with various chain lengths and stereochemistries, medium-chain prenyl diphosphate synthases are exceptional in that they comprise two dissociable heteromeric protein components. These components exist without binding with each other under physiological conditions, and neither of them has any prenyltransferase activity by itself. In order to elucidate the precise molecular mechanism underlying expression of the catalytic function by such a unique two-component system, we examined the possibility of forming a hybrid between two of the components of three different medium-chain prenyl diphosphate synthases, components I and II of heptaprenyl diphosphate synthase from Bacillus subtilis, components I' and II' of heptaprenyl diphosphate synthase from Bacillus stearothermophilus, and components A and B of hexaprenyl diphosphate synthase from Micrococcus luteus B-P 26. As a result, only the hybrid-type combination of component I and component II' gave distinct prenyltransferase activity. The hybrid-type enzyme catalyzed the synthesis of heptaprenyl diphosphate and showed moderate heat stability, which lay between those of the natural enzymes from B. subtilis and B. stearothermophilus. There is no possibility of forming a hybrid between the heptaprenyl and hexaprenyl diphosphate synthases.

  3. Aldosterone concentrations in saliva reflect the duration and severity of depressive episode in a sex dependent manner.

    PubMed

    Segeda, V; Izakova, L; Hlavacova, N; Bednarova, A; Jezova, D

    2017-08-01

    Evidence is accumulating that aldosterone may exert central actions and influence mental functions. The aim of the present study was to test the hypothesis that major depressive disorder affects the diurnal variation of salivary aldosterone and that aldosterone concentrations reflect the duration and severity of the depressive episode in a sex dependent manner. The sample consisted of 60 patients (37 postmenopausal women, 23 men) with major depressive disorder. Patients were examined two times, in acute depressive episode (admission to the hospital) and after reaching clinical remission (discharge). The samples of saliva were taken by the patients themselves twice a day (8.00-9.00 h in the morning and in the evening). Aldosterone concentrations were significantly higher in women compared to men and were significantly higher at the time of admission to the hospital compared to those at the discharge. Morning but not evening salivary aldosterone concentrations reflected the length of the depressive episode in women as well as the severity of the disorder in both sexes. Moreover, the patients with depression failed to exert known daily rhythmicity of aldosterone release. The present study brings several pieces of evidence suggesting the association of aldosterone with the pathophysiology of depression. Salivary aldosterone concentrations appear to reflect the outcome, the duration and the severity of the depressive episode in a sex dependent manner. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Aldosterone and glomerular filtration--observations in the general population.

    PubMed

    Hannemann, Anke; Rettig, Rainer; Dittmann, Kathleen; Völzke, Henry; Endlich, Karlhans; Nauck, Matthias; Wallaschofski, Henri

    2014-03-10

    Increasing evidence suggests that aldosterone promotes renal damage. Since data on the association between aldosterone and renal function in the general population are sparse, we chose to address this issue. We investigated the associations between the plasma aldosterone concentration (PAC) or the aldosterone-to-renin ratio (ARR) and the estimated glomerular filtration rate (eGFR) in a sample of adult men and women from Northeast Germany. A study population of 1921 adult men and women who participated in the first follow-up of the Study of Health in Pomerania was selected. None of the subjects used drugs that alter PAC or ARR. The eGFR was calculated according to the four-variable Modification of Diet in Renal Disease formula. Chronic kidney disease (CKD) was defined as an eGFR < 60 ml/min/1.73 m2. Linear regression models, adjusted for sex, age, waist circumference, diabetes mellitus, smoking status, systolic and diastolic blood pressures, serum triglyceride concentrations and time of blood sampling revealed inverse associations of PAC or ARR with eGFR (ß-coefficient for log-transformed PAC -3.12, p < 0.001; ß-coefficient for log-transformed ARR -3.36, p < 0.001). Logistic regression models revealed increased odds for CKD with increasing PAC (odds ratio for a one standard deviation increase in PAC: 1.35, 95% confidence interval: 1.06-1.71). There was no statistically significant association between ARR and CKD. Our study demonstrates that PAC and ARR are inversely associated with the glomerular filtration rate in the general population.

  5. Renin angiotensin aldosterone system altered in resistant hypertension in Sub-Saharan African diabetes patients without evidence of primary hyperaldosteronism.

    PubMed

    Edinga-Melenge, Bertille Elodie; Ama Moor, Vicky J; Nansseu, Jobert Richie N; Nguetse Djoumessi, Romance; Mengnjo, Michel K; Katte, Jean-Claude; Noubiap, Jean Jacques N; Sobngwi, Eugene

    2017-01-01

    The renin-angiotensin-aldosterone system may be altered in patients with resistant hypertension. This study aimed to evaluate the relation between renin-angiotensin-aldosterone system activity and resistant hypertension in Cameroonian diabetes patients with resistant hypertension. We carried out a case-control study including 19 diabetes patients with resistant hypertension and 19 diabetes patients with controlled hypertension matched to cases according to age, sex and duration of hypertension since diagnosis. After collection of data, fasting blood was collected for measurement of sodium, potassium, chloride, active renin and plasma aldosterone of which the aldosterone-renin ratio was derived to assess the activity of renin-angiotensin-aldosterone system. Then, each participant received 2000 ml infusion of saline solution after which plasma aldosterone was re-assayed. Potassium levels were lower among cases compared to controls (mean: (4.10 ± 0.63 mmol/l vs. 4.47 ± 0.58 mmol/l), though nonsignificant (p = 0.065). Active renin, plasma aldosterone both before and after the dynamic test and aldosterone-renin ratio were comparable between cases and controls (all p values > 0.05). Plasma aldosterone significantly decreased after the dynamic test in both groups (p < 0.001), but no participant exhibited a post-test value>280 pmol/l. We found a significant negative correlation between potassium ion and plasma aldosterone (ρ = -0.324; p  = 0.047), the other correlations being weak and unsignificant. Although this study failed to show an association between RH and primary hyperaldosteronism in our context, there was a hyperactivity of renin-angiotensin-aldosterone system. Moreover, this study confirms the importance of potassium dosage when screening the renin-angiotensin-aldosterone system.

  6. Cloning and expression of trehalose-6-phosphate synthase 1 from Rhizopus oryzae.

    PubMed

    Ozer Uyar, Ebru; Yücel, Meral; Hamamcı, Haluk

    2016-05-01

    Trehalose is a reducing disaccharide acting as a protectant against environmental stresses in many organisms. In fungi, Trehalose-6-phosphate synthase 1 (TPS1) plays a key role in the biosynthesis of trehalose. In this study, a full-length cDNA from Rhizopus oryzae encoding TPS1 (designated as RoTPS1) was isolated. The RoTPS1 cDNA is composed of 2505 nucleotides and encodes a protein of 834 amino acids with a molecular mass of 97.8 kDa. The amino acid sequence of RoTPS1 has a relatively high homology with the TPS1s in several other filamentous fungi. RoTPS1 was cloned into Saccharomyces cerevisiae and secretively expressed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Orthostatic responses to nitric oxide synthase inhibition in persons with tetraplegia.

    PubMed

    Wecht, Jill M; Radulovic, Miroslav; Lafountaine, Michael F; Rosado-Rivera, Dwindally; Zhang, Run-Lin; Bauman, William A

    2009-08-01

    To determine the effects of 1.0 mg/kg nitro-L-arginine methyl ester (L-NAME) on orthostatic mean arterial pressure (MAP), serum aldosterone, and plasma renin concentrations in persons with chronic tetraplegia compared with nonspinal cord-injured controls. Prospective placebo-controlled intervention study. James J. Peters Veterans Affairs Medical Center. Patients (n=5) with tetraplegia and controls (n=7) participated. The groups were matched for age, height, and weight; the average duration of injury in the tetraplegia group was 22+/-14 years. Subjects with tetraplegia visited the laboratory twice, receiving placebo on day 1 and L-NAME (1.0 mg/kg) on day 2. The agents were infused via an intravenous catheter over 60 minutes with the patient in the supine position. Data were collected during the infusion and then during head-up tilt to 45 degrees for 30 minutes. Control subjects visited the laboratory once for placebo infusion and the head-up tilt maneuver. Orthostatic MAP. Orthostatic MAP was reduced after placebo infusion in subjects with tetraplegia compared with controls (69+/-11 vs 89+/-9 mmHg, respectively; P<.01) and compared with L-NAME infusion (90+/-16 mmHg; P<.01). Orthostatic MAP did not differ when comparing the tetraplegia group with controls after L-NAME infusion. Orthostatic aldosterone levels were increased after placebo compared with L-NAME infusion in persons with tetraplegia; plasma renin levels did not differ among the groups. These data suggest that nitric oxide synthase inhibition may have clinical potential for treatment of orthostatic hypotension in persons with chronic tetraplegia.

  8. Increased chalcone synthase (CHS) expression is associated with dicamba resistance in Kochia scoparia.

    PubMed

    Pettinga, Dean J; Ou, Junjun; Patterson, Eric L; Jugulam, Mithila; Westra, Philip; Gaines, Todd A

    2017-10-30

    Resistance to the synthetic auxin herbicide dicamba is increasingly problematic in Kochia scoparia. The resistance mechanism in an inbred dicamba-resistant K. scoparia line (9425R) was investigated using physiological and transcriptomics (RNA-Seq) approaches. No differences were found in dicamba absorption or metabolism between 9425R and a dicamba-susceptible line, but 9425R was found to have significantly reduced dicamba translocation. Known auxin-responsive genes ACC synthase (ACS) and indole-3-acetic acid amino synthetase (GH3) were transcriptionally induced following dicamba treatment in dicamba-susceptible K. scoparia but not in 9425R. Chalcone synthase (CHS), the gene regulating synthesis of the flavonols quertecin and kaemperfol, was found to have twofold higher transcription in 9425R both without and 12 h after dicamba treatment. Increased CHS transcription co-segregated with dicamba resistance in a forward genetics screen using an F 2 population. Prior work has shown that the flavonols quertecin and kaemperfol compete with auxin for intercellular movement and vascular loading via ATP-binding cassette subfamily B (ABCB) membrane transporters. The results of this study support a model in which constitutively increased CHS expression in the meristem produces more flavonols that would compete with dicamba for intercellular transport by ABCB transporters, resulting in reduced dicamba translocation. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  9. Unusual features of a recombinant apple alpha-farnesene synthase.

    PubMed

    Green, Sol; Friel, Ellen N; Matich, Adam; Beuning, Lesley L; Cooney, Janine M; Rowan, Daryl D; MacRae, Elspeth

    2007-01-01

    A recombinant alpha-farnesene synthase from apple (Malus x domestica), expressed in Escherichia coli, showed features not previously reported. Activity was enhanced 5-fold by K(+) and all four isomers of alpha-farnesene, as well as beta-farnesene, were produced from an isomeric mixture of farnesyl diphosphate (FDP). Monoterpenes, linalool, (Z)- and (E)-beta-ocimene and beta-myrcene, were synthesised from geranyl diphosphate (GDP), but at 18% of the optimised rate for alpha-farnesene synthesis from FDP. Addition of K(+) reduced monoterpene synthase activity. The enzyme also produced alpha-farnesene by a reaction involving coupling of GDP and isoprenyl diphosphate but at <1% of the rate with FDP. Mutagenesis of active site aspartate residues removed sesquiterpene, monoterpene and prenyltransferase activities suggesting catalysis through the same active site. Phylogenetic analysis clusters this enzyme with isoprene synthases rather than with other sesquiterpene synthases, suggesting that it has evolved differently from other plant sesquiterpene synthases. This is the first demonstration of a sesquiterpene synthase possessing prenyltransferase activity.

  10. Aldosterone, Renin, and Diabetes Mellitus in African Americans: The Jackson Heart Study

    PubMed Central

    Joseph, Joshua J.; Echouffo-Tcheugui, Justin B.; Kalyani, Rita R.; Yeh, Hsin-Chieh; Bertoni, Alain G.; Effoe, Valery S.; Casanova, Ramon; Sims, Mario; Correa, Adolfo; Wu, Wen-Chih; Wand, Gary S.

    2016-01-01

    Context: Previous research has suggested that activation of the renin-angiotensin-aldosterone system may promote insulin resistance and β-cell dysfunction, but the association with incident diabetes in African Americans is unknown. Objective: We examined the association of aldosterone and renin with insulin resistance, β-cell function, and incident diabetes in a large African American cohort. Design: The Jackson Heart Study is a prospective study of the development and progression of cardiovascular disease in African Americans. Setting: Participants were recruited from the tricounty area of metropolitan Jackson, Mississippi. Participants: A total of 5301 African American adults, aged 21–94 years, were assessed at baseline and through 12 years of follow-up. Data on aldosterone, renin, and risk factors were collected at baseline (2000–2004). Diabetes (fasting glucose ≥ 126 mg/dL, physician diagnosis, use of diabetes drugs, or glycated hemoglobin ≥ 6.5%) was assessed at baseline and through 12 years of follow-up. Participants were excluded for missing data on baseline covariates or diabetes follow-up. Cox regression was used to estimate hazard ratios (HR) for incident diabetes using sequential modeling adjusting for age, sex, education, occupation, systolic blood pressure, current smoking, physical activity, dietary intake, and body mass index. Exposures: Aldosterone, renin, and diabetes risk factors were measured. Outcomes: Outcomes included the homeostatic model assessment of insulin resistance (HOMA-IR) and incident diabetes. Results: Among 3234 participants over a median of 8.0 years of follow-up, there were 554 cases of incident diabetes. Every 1% increase in log-transformed aldosterone was associated with a 0.18% higher log-transformed HOMA-IR in cross-sectional analyses of nondiabetic participants (P < .001). Log-transformed aldosterone and renin levels in the fifth vs first quintile were associated with a 78% (HR 1.78, 95% confidence interval 1.35

  11. Tristetraprolin regulates the expression of the human inducible nitric-oxide synthase gene.

    PubMed

    Fechir, Marcel; Linker, Katrin; Pautz, Andrea; Hubrich, Thomas; Förstermann, Ulrich; Rodriguez-Pascual, Fernando; Kleinert, Hartmut

    2005-06-01

    The expression of human inducible NO synthase (iNOS) is regulated both by transcriptional and post-transcriptional mechanisms. Stabilization of mRNAs often depends on activation of p38 mitogen-activated protein kinase (p38 MAPK). In human DLD-1 cells, inhibition of p38 MAPK by the compound 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB203580) or by overexpression of a dominant-negative p38 MAPKalpha protein resulted in a reduction of human iNOS mRNA and protein expression, whereas human iNOS promoter activity was not affected. An important RNA binding protein regulated by the p38 MAPK pathway and involved in the regulation of the stability of several mRNAs is tristetraprolin. RNase protection, quantitative real-time polymerase chain reaction, and Western blot experiments showed that cytokines used to induce iNOS expression in DLD-1 cells also enhanced tristetraprolin expression. SB203580 incubation reduced cytokine-mediated enhancement of tristetraprolin expression. Overexpression or down-regulation of tristetraprolin in stably transfected DLD-1- or A549/8 cells consistently resulted in enhanced or reduced iNOS expression by modulating iNOS-mRNA stability. In UV cross-linking experiments, recombinant tristetraprolin did not interact with the human iNOS mRNA. However, coimmunoprecipitation experiments showed interaction of tristetraprolin with the KH-type splicing regulatory protein (KSRP), which is known to recruit mRNAs containing AU-rich elements to the exosome for degradation. This tristetraprolin-KSRP interaction was enhanced by cytokines and reduced by SB203580 treatment. We conclude that tristetraprolin positively regulates human iNOS expression by enhancing the stability of human iNOS mRNA. Because tristetraprolin does not directly bind to the human iNOS mRNA but interacts with KSRP, tristetraprolin is likely to stabilize iNOS mRNA by capturing the KSRP-exosome complex.

  12. Functional TASK-3-Like Channels in Mitochondria of Aldosterone-Producing Zona Glomerulosa Cells.

    PubMed

    Yao, Junlan; McHedlishvili, David; McIntire, William E; Guagliardo, Nick A; Erisir, Alev; Coburn, Craig A; Santarelli, Vincent P; Bayliss, Douglas A; Barrett, Paula Q

    2017-08-01

    Ca 2+ drives aldosterone synthesis in the cytosolic and mitochondrial compartments of the adrenal zona glomerulosa cell. Membrane potential across each of these compartments regulates the amplitude of the Ca 2+ signal; yet, only plasma membrane ion channels and their role in regulating cell membrane potential have garnered investigative attention as pathological causes of human hyperaldosteronism. Previously, we reported that genetic deletion of TASK-3 channels (tandem pore domain acid-sensitive K + channels) from mice produces aldosterone excess in the absence of a change in the cell membrane potential of zona glomerulosa cells. Here, we report using yeast 2-hybrid, immunoprecipitation, and electron microscopic analyses that TASK-3 channels are resident in mitochondria, where they regulate mitochondrial morphology, mitochondrial membrane potential, and aldosterone production. This study provides proof of principle that mitochondrial K + channels, by modulating inner mitochondrial membrane morphology and mitochondrial membrane potential, have the ability to play a pathological role in aldosterone dysregulation in steroidogenic cells. © 2017 American Heart Association, Inc.

  13. Nitric oxide synthase-I containing cortical interneurons co-express antioxidative enzymes and anti-apoptotic Bcl-2 following focal ischemia: evidence for direct and indirect mechanisms towards their resistance to neuropathology.

    PubMed

    Bidmon, H J; Emde, B; Kowalski, T; Schmitt, M; Mayer, B; Kato, K; Asayama, K; Witte, O W; Zilles, K

    2001-09-01

    Neuronal nitric oxide-I is constitutively expressed in approximately 2% of cortical interneurons and is co-localized with gamma-amino butric acid, somatostatin or neuropeptide Y. These interneurons additionally express high amounts of glutamate receptors which mediate the glutamate-induced hyperexcitation following cerebral injury, under these conditions nitric oxide production increases contributing to a potentiation of oxidative stress. However, perilesional nitric oxide synthase-I containing neurons are known to be resistant to ischemic and excitotoxic injury. In vitro studies show that nitrosonium and nitroxyl ions inactivate N-methyl-D-aspartate receptors, resulting in neuroprotection. The question remains of how these cells are protected against their own high intracellular nitric oxide production after activation. In this study, we investigated immunocytochemically nitric oxide synthase-I containing cortical neurons in rats after unilateral, cortical photothrombosis. In this model of focal ischemia, perilesional, constitutively nitric oxide synthase-I containing neurons survived and co-expressed antioxidative enzymes, such as manganese- and copper-zinc-dependent superoxide dismutases, heme oxygenase-2 and cytosolic glutathione peroxidase. This enhanced antioxidant expression was accompanied by a strong perinuclear presence of the antiapoptotic Bcl-2 protein. No colocalization was detectable with upregulated heme oxygenase-1 in glia and the superoxide and prostaglandin G(2)-producing cyclooxygenase-2 in neurons. These results suggest that nitric oxide synthase-I containing interneurons are protected against intracellular oxidative damage and apoptosis by Bcl-2 and several potent antioxidative enzymes. Since nitric oxide synthase-I positive neurons do not express superoxide-producing enzymes such as cyclooxygenase-1, xanthine oxidase and cyclooxygenase-2 in response to injury, this may additionally contribute to their resistance by reducing their internal

  14. Current laboratory requirements for adrenocorticotropic hormone and renin/aldosterone sample handling are unnecessarily restrictive.

    PubMed

    Chakera, Ali J; McDonald, Timothy J; Knight, Bridget A; Vaidya, Bijay; Jones, Angus G

    2017-02-01

    Samples for adrenocorticotropic hormone (ACTH) and aldosterone/renin analysis usually require rapid transport to the receiving laboratory for immediate separation and freezing. In practice, this means assessment is limited to hospital settings and many samples are rejected. We examined whether these requirements are necessary by assessing the stability of ACTH, aldosterone and renin over 48 hours in whole blood collected in serum gel and EDTA plasma from 31 participants. Our results show that ACTH collected into EDTA plasma is stable at room temperature for at least 6 hours, mean change at 6 hours -2.6% (95% CI -9.7 to 4.5). Both aldosterone and renin were stable collected on serum gel at room temperature for at least 6 hours: mean change aldosterone +0.2% (95% CI -3.6 to 4.0), renin -1.9% (95% CI -7.0 to3.2). Therefore, by using appropriate preservatives, ACTH and aldosterone/renin can be measured on samples collected at room temperature and processed within 6 hours. This would facilitate outpatient and emergency room assessment of these analytes. © Royal College of Physicians 2017. All rights reserved.

  15. Genomic organization and expression analysis of a farnesyl diphosphate synthase gene (FPPS2) in apples (Malus domestica Borkh.).

    PubMed

    Yuan, Kejun; Wang, Changjun; Xin, Li; Zhang, Anning; Ai, Chengxiang

    2013-07-25

    A farnesyl diphosphate synthase gene (FPPS2), which contains 11 introns and 12 exons, was isolated from the apple cultivar "White Winter Pearmain". When it was compared to our previously reported FPPS1, its each intron size was different, its each exon size was the same as that of FPPS1 gene, 30 nucleotide differences were found in its coding sequence. Based on these nucleotide differences, specific primers were designed to perform expression analysis; the results showed that it expressed in both fruit and leaf, its expression level was obviously lower than that of FPPS1 gene in fruit which was stored at 4°C for 5 weeks. This is the first report concerning two FPPS genes and their expression comparison in apples. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. REDUCTION OF ALDOSTERONE PRODUCTION IMPROVES RENAL OXIDATIVE STRESS AND FIBROSIS IN DIABETIC RATS

    PubMed Central

    Matavelli, Luis C.; Siragy, Helmy M.

    2012-01-01

    SUMMARY Aldosterone is increased in diabetes and contributes to the development of diabetic nephropathy. We hypothesized that reduction in aldosterone production in diabetes by amlodipine or aliskiren improves diabetic kidney disease by attenuating renal oxidative stress and fibrosis. Normoglycemic and streptozotocin-induced diabetes Sprague-Dawley rats were given vehicle, amlodipine or aliskiren individually and combined for six weeks. At the end of study, we evaluated BP, 24h urinary sodium (UNaV) and aldosterone excretion rates, renal interstitial fluid (RIF) levels of nitric oxide (NO), cGMP and 8-isoprostane, and renal morphology. BP was not significantly different between any of experimental groups. UNaV increased in diabetic animals and was not affected by different treatments. Urinary aldosterone excretion increased in diabetic rats receiving vehicle and decreased with amlodipine and aliskiren individually or combined. RIF NO and cGMP levels were reduced in vehicle treated diabetic rats and increased with amlodipine or aliskiren given individually and combined. RIF 8-isoprostane levels and renal immunostaining for PAS and fibronectin were increased in vehicle treated diabetic rats and decreased with aliskiren individually or combined with amlodipine. We conclude that inhibition of aldosterone by amlodipine or aliskiren ameliorates diabetes induced renal injury via improvement of NO-cGMP pathway, and reduction in oxidative stress and fibrosis, independent of BP changes. PMID:23011470

  17. Activity and expression of nitric oxide synthase in pork skeletal muscles.

    PubMed

    Liu, Rui; Li, Yu-pin; Zhang, Wan-gang; Fu, Qing-quan; Liu, Nian; Zhou, Guang-hong

    2015-01-01

    The objective of this study was to investigate the biochemical changes of nitric oxide synthase (NOS) in pork skeletal muscles during postmortem storage. Longissimus thoracis (LT), psoas major (PM) and semimembranosus (SM) muscles of pork were removed immediately after slaughter and stored under vacuum condition at 4°C for 0, 1 and 3d. Results showed that all three muscles exhibited NOS activity until 1d while SM muscle retained NOS activity after 3d of storage. The content of nNOS in SM muscle was stable across 3d of storage while decreased intensity of nNOS was detected at 1 and 3d of aging in PM and LT muscles due to the degradation of calpain. Immunostaining showed that nNOS was located at not only sarcolemma but also cytoplasm at 0 and 1d of storage. Our data suggest that postmortem muscles possess NOS activity and nNOS expression depends on muscle type. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Chlorophyll Synthase under Epigenetic Surveillance Is Critical for Vitamin E Synthesis, and Altered Expression Affects Tocopherol Levels in Arabidopsis1[OPEN

    PubMed Central

    Zhang, Chunyu; Zhang, Wei; Ren, Guodong; Li, Delin; Cahoon, Rebecca E.; Chen, Ming; Zhou, Yongming; Yu, Bin

    2015-01-01

    Chlorophyll synthase catalyzes the final step in chlorophyll biosynthesis: the esterification of chlorophyllide with either geranylgeranyl diphosphate or phytyl diphosphate (PDP). Recent studies have pointed to the involvement of chlorophyll-linked reduction of geranylgeranyl by geranylgeranyl reductase as a major pathway for the synthesis of the PDP precursor of tocopherols. This indirect pathway of PDP synthesis suggests a key role of chlorophyll synthase in tocopherol production to generate the geranylgeranyl-chlorophyll substrate for geranylgeranyl reductase. In this study, contributions of chlorophyll synthase to tocopherol formation in Arabidopsis (Arabidopsis thaliana) were explored by disrupting and altering expression of the corresponding gene CHLOROPHYLL SYNTHASE (CHLSYN; At3g51820). Leaves from the homozygous chlysyn1-1 null mutant were nearly devoid of tocopherols, whereas seeds contained only approximately 25% of wild-type tocopherol levels. Leaves of RNA interference lines with partial suppression of CHLSYN displayed marked reductions in chlorophyll but up to a 2-fold increase in tocopherol concentrations. Cauliflower mosaic virus35S-mediated overexpression of CHLSYN unexpectedly caused a cosuppression phenotype at high frequencies accompanied by strongly reduced chlorophyll content and increased tocopherol levels. This phenotype and the associated detection of CHLSYN-derived small interfering RNAs were reversed with CHLSYN overexpression in rna-directed rna polymerase6 (rdr6), which is defective in RNA-dependent RNA polymerase6, a key enzyme in sense transgene-induced small interfering RNA production. CHLSYN overexpression in rdr6 had little effect on chlorophyll content but resulted in up to a 30% reduction in tocopherol levels in leaves. These findings show that altered CHLSYN expression impacts tocopherol levels and also, show a strong epigenetic surveillance of CHLSYN to control chlorophyll and tocopherol synthesis. PMID:26048882

  19. Endothelial mineralocorticoid receptor activation mediates endothelial dysfunction in diet-induced obesity

    PubMed Central

    Schäfer, Nicola; Lohmann, Christine; Winnik, Stephan; van Tits, Lambertus J.; Miranda, Melroy X.; Vergopoulos, Athanasios; Ruschitzka, Frank; Nussberger, Jürg; Berger, Stefan; Lüscher, Thomas F.; Verrey, François; Matter, Christian M.

    2013-01-01

    Received 22 July 2012; revised 29 January 2013; accepted 4 March 2013 Aims Aldosterone plays a crucial role in cardiovascular disease. ‘Systemic’ inhibition of its mineralocorticoid receptor (MR) decreases atherosclerosis by reducing inflammation and oxidative stress. Obesity, an important cardiovascular risk factor, is an inflammatory disease associated with increased plasma aldosterone levels. We have investigated the role of the ‘endothelial’ MR in obesity-induced endothelial dysfunction, the earliest stage in atherogenesis. Methods and results C57BL/6 mice were exposed to a normal chow diet (ND) or a high-fat diet (HFD) alone or in combination with the MR antagonist eplerenone (200 mg/kg/day) for 14 weeks. Diet-induced obesity impaired endothelium-dependent relaxation in response to acetylcholine, whereas eplerenone treatment of obese mice prevented this. Expression analyses in aortic endothelial cells isolated from these mice revealed that eplerenone attenuated expression of pro-oxidative NADPH oxidase (subunits p22phox, p40phox) and increased expression of antioxidative genes (glutathione peroxidase-1, superoxide dismutase-1 and -3) in obesity. Eplerenone did not affect obesity-induced upregulation of cyclooxygenase (COX)-1 or prostacyclin synthase. Endothelial-specific MR deletion prevented endothelial dysfunction in obese (exhibiting high ‘endogenous’ aldosterone) and in ‘exogenous’ aldosterone-infused lean mice. Pre-incubation of aortic rings from aldosterone-treated animals with the COX-inhibitor indomethacin restored endothelial function. Exogenous aldosterone administration induced endothelial expression of p22phox in the presence, but not in the absence of the endothelial MR. Conclusion Obesity-induced endothelial dysfunction depends on the ‘endothelial’ MR and is mediated by an imbalance of oxidative stress-modulating mechanisms. Therefore, MR antagonists may represent an attractive therapeutic strategy in the increasing population

  20. Diversity of sesquiterpene synthases in the basidiomycete Coprinus cinereus

    PubMed Central

    Agger, Sean; Lopez-Gallego, Fernando; Schmidt-Dannert, Claudia

    2009-01-01

    SUMMARY Fungi are a rich source of bioactive secondary metabolites and mushroom-forming fungi (Agaricomycetes) are especially known for the synthesis of numerous bioactive and often cytotoxic sesquiterpenoid secondary metabolites. Compared to the large number of sesquiterpene synthases identified in plants, less than a handful of unique sesquiterpene synthases have been described from fungi. Here we describe the functional characterization of six sesquiterpene synthases (Cop1 to Cop6) and two terpene oxidizing cytochrome P450 monooxygenases (Cox1 and Cox2) from Coprinus cinereus. The genes were cloned and, except for cop5, functionally expressed in Escherichia coli and/or Saccharomyces cerevisiae. Cop1 and Cop2 each synthesize germacrene A as the major product. Cop3 was identified as a α-muurolene synthase, an enzyme that has not been described previously, while Cop4 synthesizes δ-cadinene as its major product. Cop6 was originally annotated as a trichodiene synthase homolog, but instead was found to catalyze highly specific the synthesis of α-cuprenene. Co-expression of cop6 and the two monooxygenase genes next to it yields oxygenated α-cuprenene derivatives, including cuparophenol, suggesting that these genes encode the enzymes for the biosynthesis of antimicrobial quinone sesquiterpenoids (known as lagopodins) that were previously isolated from C. cinereus and other Coprinus species. PMID:19400802

  1. Circulating Aldosterone and Natriuretic Peptides in the General Community: Relationship to Cardiorenal and Metabolic Disease

    PubMed Central

    Buglioni, Alessia; Cannone, Valentina; Cataliotti, Alessandro; Sangaralingham, S. Jeson; Heublein, Denise M.; Scott, Christopher G.; Bailey, Kent R.; Rodeheffer, Richard J.; Dessì-Fulgheri, Paolo; Sarzani, Riccardo; Burnett, John C.

    2014-01-01

    We sought to investigate the role of aldosterone as a mediator of disease and its relationship with the counter-regulatory natriuretic peptide (NP) system. We measured plasma aldosterone (n=1674; age ≥45 years old) in a random sample of the general population from Olmsted County, MN. In a multivariate logistic regression model, aldosterone analyzed as a continuous variable was associated with hypertension (HTN) (OR=1.75, 95%CI= 1.57,1.96; p<0.0001), obesity (OR=1.34, 95%CI= 1.21,1.48; p<0.0001), chronic kidney disease (CKD) (OR=1.39, 95%CI= 1.22,1.60; p<0.0001), central obesity (OR=1.47, 95%CI=1.32,1.63; p<0.0001), metabolic syndrome (MetS) (OR=1.41, 95%CI= 1.26,1.58; p<0.0001), high triglycerides (OR=1.23, 95%CI=1.11,1.36; p<0.0001), concentric left ventricular hypertrophy (cLVH) (OR=1.22, 95%CI= 1.09,1.38; p=0.0007) and atrial fibrillation (OR=1.24, 95%CI= 1.01,1.53; p=0.04), after adjusting for age and sex. The associations with HTN, central obesity, MetS, triglycerides and cLVH remained significant after further adjustment for BMI, NPs, and renal function. Furthermore, aldosterone in the highest tertile correlated with lower NP levels and increased mortality. Importantly, most of these associations remained significant even after excluding subjects with aldosterone levels above the normal range. In conclusion, we report that aldosterone is associated with HTN, CKD, obesity, MetS, cLVH, and lower NPs in the general community. Our data suggests that aldosterone, even within the normal range, may be a biomarker of cardiorenal and metabolic disease. Further studies are warranted to evaluate a therapeutic and preventive strategy to delay the onset and/or progression of disease, using mineralocorticoid antagonists or chronic NP administration in high risk subjects identified by plasma aldosterone. PMID:25368032

  2. Impaired natriuretic response to high-NaCl diet plus aldosterone infusion in mice overexpressing human CD39, an ectonucleotidase (NTPDase1).

    PubMed

    Zhang, Yue; Robson, Simon C; Morris, Kaiya L; Heiney, Kristina M; Dwyer, Karen M; Kishore, Bellamkonda K; Ecelbarger, Carolyn M

    2015-06-15

    Extracellular nucleotides acting through P2 receptors facilitate natriuresis. To define how purinergic mechanisms are involved in sodium homeostasis, we used transgenic (TG) mice that globally overexpress human CD39 (hCD39, NTPDase1), an ectonucleotidase that hydrolyzes extracellular ATP/ADP to AMP, resulting in an altered extracellular purine profile. On a high-sodium diet (HSD, 3.5% Na(+)), urine volume and serum sodium were significantly higher in TG mice but sodium excretion was unaltered. Furthermore, TG mice showed an attenuated fall in urine aldosterone with HSD. Western blot analysis revealed significantly lower densities (∼40%) of the β-subunit of the epithelial sodium channel (ENaC) in medulla, and the major band (85-kDa) of γ-ENaC in TG mice cortex. To evaluate aldosterone-independent differences, in a second experiment, aldosterone was clamped by osmotic minipump at 20 μg/day, and mice were fed either an HSD or a low-sodium diet (LSD, 0.03% Na(+)). Here, no differences in urine volume or osmolality, or serum aldosterone were found, but TG mice showed a modest, yet significant impairment in late natriuresis (days 3 and 4). Several major sodium transporters or channel subunits were differentially expressed between the genotypes. HSD caused a downregulation of Na-Cl cotransporter (NCC) in both genotypes; and had higher cortical levels of NCC, Na-K-ATPase (α-1 subunit), and α- and γ-ENaC. The Na-K-2Cl cotransporter (NKCC2) was downregulated by HSD in wild-type mice, but it increased in TG mice. In summary, our data support the concept that extracellular nucleotides facilitate natriuresis; they also reveal an aldosterone-independent downregulation of major renal sodium transporters and channel subunits by purinergic signaling.

  3. An unusual plant triterpene synthase with predominant α-amyrin-producing activity identified by characterizing oxidosqualene cyclases from Malus × domestica.

    PubMed

    Brendolise, Cyril; Yauk, Yar-Khing; Eberhard, Ellen D; Wang, Mindy; Chagne, David; Andre, Christelle; Greenwood, David R; Beuning, Lesley L

    2011-07-01

    The pentacyclic triterpenes, in particular ursolic acid and oleanolic acid and their derivatives, exist abundantly in the plant kingdom, where they are well known for their anti-inflammatory, antitumour and antimicrobial properties. α-Amyrin and β-amyrin are the precursors of ursolic and oleanolic acids, respectively, formed by concerted cyclization of squalene epoxide by a complex synthase reaction. We identified three full-length expressed sequence tag sequences in cDNA libraries constructed from apple (Malus × domestica 'Royal Gala') that were likely to encode triterpene synthases. Two of these expressed sequence tag sequences were essentially identical (> 99% amino acid similarity; MdOSC1 and MdOSC3). MdOSC1 and MdOSC2 were expressed by transient expression in Nicotiana benthamiana leaves and by expression in the yeast Pichia methanolica. The resulting products were analysed by GC and GC-MS. MdOSC1 was shown to be a mixed amyrin synthase (a 5 : 1 ratio of α-amyrin to β-amyrin). MdOSC1 is the only triterpene synthase so far identified in which the level of α-amyrin produced is > 80% of the total product and is, therefore, primarily an α-amyrin synthase. No product was evident for MdOSC2 when expressed either transiently or in yeast, suggesting that this putative triterpene synthase is either encoded by a pseudogene or does not express well in these systems. Transcript expression analysis in Royal Gala indicated that the genes are mostly expressed in apple peel, and that the MdOSC2 expression level was much lower than that of MdOSC1 and MdOSC3 in all the tissues tested. Amyrin content analysis was undertaken by LC-MS, and demonstrated that levels and ratios differ between tissues, but that the true consequence of synthase activity is reflected in the ursolic/oleanolic acid content and in further triterpenoids derived from them. Phylogenetic analysis placed the three triterpene synthase sequences with other triterpene synthases that encoded either

  4. Use of aldosterone antagonists in resistant hypertension.

    PubMed

    Calhoun, David A

    2006-01-01

    Resistant hypertension is defined as an elevated blood pressure in spite of treatment with 3 different antihypertensive agents. The prevalence of resistant hypertension is unknown, but recent cross-sectional analyses and hypertension outcome studies suggest it is a common clinical problem and will become even more so with an aging and increasingly heavy population. Secondary causes of hypertension are common in patients with resistant hypertension, in particular, obstructive sleep apnea and hyperaldosteronism. Treatment of resistant hypertension is predicated upon identification and reversal of secondary causes of hypertension, as possible, and effective use of multidrug regimens. Recent clinical studies indicate that aldosterone antagonists, spironolactone and amiloride, provide significant additional blood pressure reduction when added to treatment regimens of patients with resistant hypertension. Both agents are generally well tolerated. Hyperkalemia is an uncommon complication of aldosterone antagonists, but it can occur; therefore, biochemical monitoring is necessary, particularly in high-risk patients.

  5. Aldosterone regulation of sodium and potassium transport in the cortical collecting duct.

    PubMed

    O'Neil, R G

    1990-07-01

    The aldosterone-induced up-regulation of Na absorption and K secretion in the CCD is complex and involves the regulation of numerous transport proteins. Some aspects of the response may be species dependent. For example, stimulation of Na and K transport in the rabbit CCD involves a marked up-regulation in the apical cell membrane Na and K conductances, the basolateral cell membrane K conductance, and the basolateral membrane NaK-ATPase activity. In the rat CCD, aldosterone causes a similar up-regulation in the NaK-ATPase and the apical membrane Na conductance, but supposedly has little influence on the apical and basolateral membrane K conductances as evaluated by indirect methods. Furthermore, the marked hyperpolarization of the basolateral membrane with long-term aldosterone treatment in the rabbit CCD is blunted or absent in the rat CCD. Other differences between the CCD of these two species have been outlined. Nonetheless, the basic responses of the CCDs from the two species show similar trends. The actions of aldosterone in the CCD principal cell are summarized in Figure 5. The initial steps have been described previously. Aldosterone (A) diffuse across the cell membrane and binds to a cytoplasmic receptor (R). The receptor complex moves into the nucleus and binds to an acceptor site on chromatin, initiating transcription and the subsequent synthesis of a myriad of new proteins referred to as aldosterone-induced proteins (AIP). The initial observed action of aldosterone is an upregulation of the apical membrane Na conductance during the early phase, which occurs within 1 to 2 hours. The increase in Na conductance likely reflects activation of preexisting latent Na channels and not synthesis of new channels, although activation does require protein synthesis. The increased Na influx during the early phase presents a larger Na load to the Na pump, which is likely reflected as a modest transient increase in intracellular Na activity. Based on kinetic

  6. Estradiol increases urethral tone through the local inhibition of neuronal nitric oxide synthase expression.

    PubMed

    Gamé, Xavier; Allard, Julien; Escourrou, Ghislaine; Gourdy, Pierre; Tack, Ivan; Rischmann, Pascal; Arnal, Jean-François; Malavaud, Bernard

    2008-03-01

    Estrogens are known to modulate lower urinary tract (LUT) trophicity and neuronal nitric oxide synthase (nNOS) expression in several organs. The aim of this study was to explore the effects of endogenous and supraestrus levels of 17beta-estradiol (E2) on LUT and urethral nNOS expression and function. LUT function and histology and urethral nNOS expression were studied in adult female mice subjected either to sham surgery, surgical castration, or castration plus chronic E2 supplementation (80 microg.kg(-1).day(-1), i.e., pregnancy level). The micturition pattern was profoundly altered by long-term supraestrus levels of E2 with decreased frequency paralleled by increased residual volumes higher than those of ovariectomized mice. Urethral resistance was increased twofold in E2-treated mice, with no structural changes in urethra, supporting a pure tonic mechanism. Acute nNOS inhibition by 7-nitroindazole decreased frequency and increased residual volumes in ovariectomized mice but had no additive effect on the micturition pattern of long-term supraestrus mice, showing that long-term supraestrus E2 levels and acute inhibition of nNOS activity had similar functional effects. Finally, E2 decreased urethral nNOS expression in ovariectomized mice. Long-term supraestrus levels of E2 increased urethral tone through inhibition of nNOS expression, whereas physiological levels of E2 had no effect.

  7. Cloning of a cDNA encoding 1-aminocyclopropane-1-carboxylate synthase and expression of its mRNA in ripening apple fruit.

    PubMed

    Dong, J G; Kim, W T; Yip, W K; Thompson, G A; Li, L; Bennett, A B; Yang, S F

    1991-08-01

    1-Aminocyclopropane-1-carboxylate (ACC) synthase (EC 4.4.1.14) purified from apple (Malus sylvestris Mill.) fruit was subjected to trypsin digestion. Following separation by reversed-phase high-pressure liquid chromatography, ten tryptic peptides were sequenced. Based on the sequences of three tryptic peptides, three sets of mixed oligonucleotide probes were synthesized and used to screen a plasmid cDNA library prepared from poly(A)(+) RNA of ripe apple fruit. A 1.5-kb (kilobase) cDNA clone which hybridized to all three probes were isolated. The clone contained an open reading frame of 1214 base pairs (bp) encoding a sequence of 404 amino acids. While the polyadenine tail at the 3'-end was intact, it lacked a portion of sequence at the 5'-end. Using the RNA-based polymerase chain reaction, an additional sequence of 148 bp was obtained at the 5'-end. Thus, 1362 bp were sequenced and they encode 454 amino acids. The deduced amino-acid sequence contained peptide sequences corresponding to all ten tryptic fragments, confirming the identity of the cDNA clone. Comparison of the deduced amino-acid sequence between ACC synthase from apple fruit and those from tomato (Lycopersicon esculentum Mill.) and winter squash (Cucurbita maxima Duch.) fruits demonstrated the presence of seven highly conserved regions, including the previously identified region for the active site. The size of the translation product of ACC-synthase mRNA was similar to that of the mature protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), indicating that apple ACC-synthase undergoes only minor, if any, post-translational proteolytic processing. Analysis of ACC-synthase mRNA by in-vitro translation-immunoprecipitation, and by Northern blotting indicates that the ACC-synthase mRNA was undetectable in unripe fruit, but was accumulated massively during the ripening proccess. These data demonstrate that the expression of the ACC-synthase gene is developmentally regulated.

  8. Genetic and epigenetic influences on expression of spermine synthase and spermine oxidase in suicide completers.

    PubMed

    Fiori, Laura M; Turecki, Gustavo

    2010-07-01

    Alterations in the levels of spermine synthase (SMS) and spermine oxidase (SMOX), two enzymes involved in polyamine metabolism, have previously been observed in brains of suicide completers. To characterize the roles played by genetic and epigenetic factors in determining expression levels of these genes, as well as to identify potential mechanisms by which to explain our findings in suicide completers, we (1) assessed the role of promoter polymorphisms in determining expression in the brain and in vitro, and (2) examined CpG methylation and levels of methylated histone H3 lysine-27 in the promoter regions of these genes in the prefrontal cortex of suicide completers and healthy controls. We identified several promoter haplotypes in SMS and SMOX, but found no consistent effects of haplotype on expression levels in either the brain or in reporter gene assays performed in three different cell lines. We also found no overall effects of epigenetic factors in determining expression, with the exception of a relationship between CpG methylation at one site in the promoter of SMOX and its expression in Brodmann area 8/9. In conclusion, the genetic and epigenetic factors examined in this study show little influence on the expression levels of SMS and SMOX, and do not appear to be responsible for the dysregulated expression of these genes in suicide completers.

  9. Therapeutic results of primary aldosteronism with special reference to renal or renovascular lesions.

    PubMed

    Nakada, T; Koike, H; Akiya, T; Katayama, T; Takata, M; Iida, H; Mizumura, Y

    1988-01-01

    A study was made of 9 patients with primary aldosteronism due to aldosterone-producing adenoma (APA) and 8 subjects with idiopathic adrenal hyperplasia (IHA) to clarify the pathogenesis of sustained hypertension after surgical or non-surgical treatment. Following each treatment, a complete improvement of hypertension was obtained in 12 patients (6 APA, 6 IHA), while 5 (3 APA, 2 IHA) showed still hypertensive status. Renal or renovascular lesions were prominent only in the hypertension-unchanged group. Under regular sodium diet, the ratio of urinary excretion of sodium to creatinine of this hypertensive group was significantly lower than that of the hypertension-improved group. However, the results of other renal function tests were similar in both groups. After respective treatments, suppressed plasma renin activity and elevated plasma aldosterone concentration were improved in all patients. In addition, patients of both groups showed normal response of the renin-aldosterone system following diuretic and dietary induced sodium and volume depletion. Based on these findings, renal or renovascular lesions appear to play an important role in the pathogenesis of maintenance of hypertension in this disorder after respective treatments.

  10. Aldosterone Modulates the Association between NCC and ENaC.

    PubMed

    Wynne, Brandi M; Mistry, Abinash C; Al-Khalili, Otor; Mallick, Rickta; Theilig, Franziska; Eaton, Douglas C; Hoover, Robert S

    2017-06-23

    Distal sodium transport is a final step in the regulation of blood pressure. As such, understanding how the two main sodium transport proteins, the thiazide-sensitive sodium chloride cotransporter (NCC) and the epithelial sodium channel (ENaC), are regulated is paramount. Both are expressed in the late distal nephron; however, no evidence has suggested that these two sodium transport proteins interact. Recently, we established that these two sodium transport proteins functionally interact in the second part of the distal nephron (DCT2). Given their co-localization within the DCT2, we hypothesized that NCC and ENaC interactions might be modulated by aldosterone (Aldo). Aldo treatment increased NCC and αENaC colocalization (electron microscopy) and interaction (coimmunoprecipitation). Finally, with co-expression of the Aldo-induced protein serum- and glucocorticoid-inducible kinase 1 (SGK1), NCC and αENaC interactions were increased. These data demonstrate that Aldo promotes increased interaction of NCC and ENaC, within the DCT2 revealing a novel method of regulation for distal sodium reabsorption.

  11. Saline suppression test parameters may predict bilateral subtypes of primary aldosteronism.

    PubMed

    Hashimura, Hikaru; Shen, Jimmy; Fuller, Peter J; Chee, Nicholas Y N; Doery, James C G; Chong, Winston; Choy, Kay Weng; Gwini, Stella May; Yang, Jun

    2018-06-06

    The saline suppression test (SST) serves to confirm the diagnosis of primary aldosteronism (PA) while adrenal vein sampling (AVS) is used to determine whether the aldosterone hypersecretion is unilateral or bilateral. An accurate prediction of bilateral PA based on SST results could reduce the need for AVS. We sought to identify SST parameters that reliably predict bilateral PA. The results from 121 patients undergoing SSTs at Monash Health from January 2010 to January 2018 including screening blood tests, imaging, AVS and histopathology results were evaluated. Patients were subtyped into unilateral or bilateral PA based on AVS and surgical outcomes. Of 113 patients with confirmed PA, 33 had unilateral disease while 42 had bilateral disease. In those with bilateral disease, plasma aldosterone concentration (PAC) was significantly lower post-SST, together with a significant fall in the aldosterone-renin ratio (ARR). The combination of PAC <300 pmol/L and a reduction in ARR post-SST provided 96.8% specificity in predicting bilateral disease. Eighteen out of 39 patients (49%) with bilateral PA could have avoided AVS using these criteria. A combination of PAC <300 pmol/L and a lower ARR post-SST could reliably predict bilateral PA. An independent cohort will be needed to validate these findings. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  12. The Renin Angiotensin Aldosterone System and Insulin Resistance in Humans

    PubMed Central

    Underwood, Patricia C

    2012-01-01

    Alterations in the renin angiotensin aldosterone system (RAAS) contribute to the underlying pathophysiology of insulin resistance in humans; however, individual differences in the treatment response of insulin resistance to RAAS blockade persist. Thus, understanding inter-individual differences in the relationship between the RAAS and insulin resistance may provide insights into improved personalized treatments and improved outcomes. The effects of the systemic RAAS on blood pressure regulation and glucose metabolism have been studied extensively; however, recent discoveries on the influence of local tissue RAAS in the skeletal muscle, heart, vasculature, adipocytes, and pancreas have led to an improved understanding of how activated tissue RAAS influences the development of insulin resistance and diabetes in humans. Angiotensin II (ANGII) is the predominant RAAS component contributing to insulin resistance; however, other players such as aldosterone, renin, and ACE2 are also involved. This review examines the role of local ANGII activity on insulin resistance development in skeletal muscle, adipocytes, and pancreas, followed by a discussion of the other RAAS components implicated in insulin resistance, including ACE2, Ang1-7, renin, and aldosterone. PMID:23242734

  13. Calcium-mediated signaling and calmodulin-dependent kinase regulate hepatocyte-inducible nitric oxide synthase expression.

    PubMed

    Zhang, Baochun; Crankshaw, Will; Nesemeier, Ryan; Patel, Jay; Nweze, Ikenna; Lakshmanan, Jaganathan; Harbrecht, Brian G

    2015-02-01

    Induced nitric oxide synthase (iNOS) is induced in hepatocytes by shock and inflammatory stimuli. Excessive NO from iNOS mediates shock-induced hepatic injury and death, so understanding the regulation of iNOS will help elucidate the pathophysiology of septic shock. In vitro, cytokines induce iNOS expression through activation of signaling pathways including mitogen-activated protein kinases and nuclear factor κB. Cytokines also induce calcium (Ca(2+)) mobilization and activate calcium-mediated intracellular signaling pathways, typically through activation of calmodulin-dependent kinases (CaMK). Calcium regulates NO production in macrophages but the role of calcium and calcium-mediated signaling in hepatocyte iNOS expression has not been defined. Primary rat hepatocytes were isolated, cultured, and induced to produce NO with proinflammatory cytokines. Calcium mobilization and Ca(2+)-mediated signaling were altered with ionophore, Ca(2+) channel blockers, and inhibitors of CaMK. The Ca(2+) ionophore A23187 suppressed cytokine-stimulated NO production, whereas Ethylene glycol tetraacetic acid and nifedipine increased NO production, iNOS messenger RNA, and iNOS protein expression. Inhibition of CaMK with KN93 and CBD increased NO production but the calcineurin inhibitor FK 506 decreased iNOS expression. These data demonstrate that calcium-mediated signaling regulates hepatocyte iNOS expression and does so through a mechanism independent of calcineurin. Changes in intracellular calcium levels may regulate iNOS expression during hepatic inflammation induced by proinflammatory cytokines. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Sequence Requirements of the 5-Enolpyruvylshikimate-3-phosphate Synthase 5[prime]-Upstream Region for Tissue-Specific Expression in Flowers and Seedlings.

    PubMed Central

    Benfey, PN; Takatsuji, H; Ren, L; Shah, DM; Chua, NH

    1990-01-01

    We have analyzed expression from deletion derivatives of the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) 5[prime]-upstream region in transgenic petunia flowers and seedlings. In seedlings, expression was strongest in root cortex cells and in trichomes. High-level expression in petals and in seedling roots was conferred by large (>500 base-pair) stretches of sequence, but was lost when smaller fragments were analyzed individually. This apparent requirement for extensive sequence suggests that combinations of cis-elements that are widely separated control tissue-specific expression from the EPSPS promoter. We have also used the high-level, petal-specific expression of the EPSPS promoter to change petal color in two mutant petunia lines. PMID:12354968

  15. Upregulation of Cyclooxygenase-2 Expression in Porcine Macula Densa With Chronic Nitric Oxide Synthase Inhibition

    PubMed Central

    Kommareddy, M.; McAllister, R. M.; Ganjam, V. K.; Turk, J. R.; Laughlin, M. Harold

    2012-01-01

    The objective of this study was to investigate the effects of chronic inhibition of nitric oxide synthase (NOS) on cyclooxygenase-2 (COX-2) expression in the macula densa (MD) of swine, as well as the effects on expression of related proteins. Adult female Yucatan swine were given either tap water (control, n = 6) or water with NG-nitro-l-arginine methyl ester (L-NAME, 100 mg/liter, n = 5) for a minimum of 30 days. Duplicate samples of kidney were fixed or snap frozen. There was a significant (P = .0082) upregulation of COX-2 mRNA expression in the MD of L-NAME, as well as an apparent increase in COX-2 protein. Plasma renin activity also increased with L-NAME treatment (control, 0.34 ± 0.08 ng/ml; L-NAME, 1.26 ± 0.03 ng/ml; P = .00000003). There were no differences between groups in expression of either inducible NOS or renin protein or in serum electrolyte concentrations. In conclusion, with chronic inhibition of NOS, COX-2 in MD is upregulated, perhaps to compensate for loss of nitric oxide. Increases in COX-2 products may counteract renal arteriolar constriction and sustain renin release. PMID:21160023

  16. Upregulation of cyclooxygenase-2 expression in porcine macula densa with chronic nitric oxide synthase inhibition.

    PubMed

    Kommareddy, M; McAllister, R M; Ganjam, V K; Turk, J R; Laughlin, M Harold

    2011-11-01

    The objective of this study was to investigate the effects of chronic inhibition of nitric oxide synthase (NOS) on cyclooxygenase-2 (COX-2) expression in the macula densa (MD) of swine, as well as the effects on expression of related proteins. Adult female Yucatan swine were given either tap water (control, n = 6) or water with N (G)-nitro-L-arginine methyl ester (L-NAME, 100 mg/liter, n = 5) for a minimum of 30 days. Duplicate samples of kidney were fixed or snap frozen. There was a significant (P = .0082) upregulation of COX-2 mRNA expression in the MD of L-NAME, as well as an apparent increase in COX-2 protein. Plasma renin activity also increased with L-NAME treatment (control, 0.34 ± 0.08 ng/ml; L-NAME, 1.26 ± 0.03 ng/ml; P = .00000003). There were no differences between groups in expression of either inducible NOS or renin protein or in serum electrolyte concentrations. In conclusion, with chronic inhibition of NOS, COX-2 in MD is upregulated, perhaps to compensate for loss of nitric oxide. Increases in COX-2 products may counteract renal arteriolar constriction and sustain renin release.

  17. Up-regulation of the mammalian target of rapamycin complex 1 subunit Raptor by aldosterone induces abnormal pulmonary artery smooth muscle cell survival patterns to promote pulmonary arterial hypertension

    PubMed Central

    Aghamohammadzadeh, Reza; Zhang, Ying-Yi; Stephens, Thomas E.; Arons, Elena; Zaman, Paula; Polach, Kevin J.; Matar, Majed; Yung, Lai-Ming; Yu, Paul B.; Bowman, Frederick P.; Opotowsky, Alexander R.; Waxman, Aaron B.; Loscalzo, Joseph; Leopold, Jane A.; Maron, Bradley A.

    2016-01-01

    Activation of the mammalian target of rapamycin complex 1 (mTORC1) subunit Raptor induces cell growth and is a downstream target of Akt. Elevated levels of aldosterone activate Akt, and, in pulmonary arterial hypertension (PAH), correlate with pulmonary arteriole thickening, which suggests that mTORC1 regulation by aldosterone may mediate adverse pulmonary vascular remodeling. We hypothesized that aldosterone-Raptor signaling induces abnormal pulmonary artery smooth muscle cell (PASMC) survival patterns to promote PAH. Remodeled pulmonary arterioles from SU-5416/hypoxia-PAH rats and monocrotaline-PAH rats with hyperaldosteronism expressed increased levels of the Raptor target, p70S6K, which provided a basis for investigating aldosterone-Raptor signaling in human PASMCs. Aldosterone (10−9 to 10−7 M) increased Akt/mTOR/Raptor to activate p70S6K and increase proliferation, viability, and apoptosis resistance in PASMCs. In PASMCs transfected with Raptor–small interfering RNA or treated with spironolactone/eplerenone, aldosterone or pulmonary arterial plasma from patients with PAH failed to increase p70S6K activation or to induce cell survival in vitro. Optimal inhibition of pulmonary arteriole Raptor was achieved by treatment with Staramine-monomethoxy polyethylene glycol that was formulated with Raptor-small interfering RNA plus spironolactone in vivo, which decreased arteriole muscularization and pulmonary hypertension in 2 experimental animal models of PAH in vivo. Up-regulation of mTORC1 by aldosterone is a critical pathobiologic mechanism that controls PASMC survival to promote hypertrophic vascular remodeling and PAH.—Aghamohammadzadeh, R., Zhang, Y.-Y., Stephens, T. E., Arons, E., Zaman, P., Polach, K. J., Matar, M., Yung, L.-M., Yu, P. B., Bowman, F. P., Opotowsky, A. R., Waxman, A. B., Loscalzo, J., Leopold, J. A., Maron, B. A. Up-regulation of the mammalian target of rapamycin complex 1 subunit Raptor by aldosterone induces abnormal pulmonary artery

  18. Up-regulation of the mammalian target of rapamycin complex 1 subunit Raptor by aldosterone induces abnormal pulmonary artery smooth muscle cell survival patterns to promote pulmonary arterial hypertension.

    PubMed

    Aghamohammadzadeh, Reza; Zhang, Ying-Yi; Stephens, Thomas E; Arons, Elena; Zaman, Paula; Polach, Kevin J; Matar, Majed; Yung, Lai-Ming; Yu, Paul B; Bowman, Frederick P; Opotowsky, Alexander R; Waxman, Aaron B; Loscalzo, Joseph; Leopold, Jane A; Maron, Bradley A

    2016-07-01

    Activation of the mammalian target of rapamycin complex 1 (mTORC1) subunit Raptor induces cell growth and is a downstream target of Akt. Elevated levels of aldosterone activate Akt, and, in pulmonary arterial hypertension (PAH), correlate with pulmonary arteriole thickening, which suggests that mTORC1 regulation by aldosterone may mediate adverse pulmonary vascular remodeling. We hypothesized that aldosterone-Raptor signaling induces abnormal pulmonary artery smooth muscle cell (PASMC) survival patterns to promote PAH. Remodeled pulmonary arterioles from SU-5416/hypoxia-PAH rats and monocrotaline-PAH rats with hyperaldosteronism expressed increased levels of the Raptor target, p70S6K, which provided a basis for investigating aldosterone-Raptor signaling in human PASMCs. Aldosterone (10(-9) to 10(-7) M) increased Akt/mTOR/Raptor to activate p70S6K and increase proliferation, viability, and apoptosis resistance in PASMCs. In PASMCs transfected with Raptor-small interfering RNA or treated with spironolactone/eplerenone, aldosterone or pulmonary arterial plasma from patients with PAH failed to increase p70S6K activation or to induce cell survival in vitro Optimal inhibition of pulmonary arteriole Raptor was achieved by treatment with Staramine-monomethoxy polyethylene glycol that was formulated with Raptor-small interfering RNA plus spironolactone in vivo, which decreased arteriole muscularization and pulmonary hypertension in 2 experimental animal models of PAH in vivo Up-regulation of mTORC1 by aldosterone is a critical pathobiologic mechanism that controls PASMC survival to promote hypertrophic vascular remodeling and PAH.-Aghamohammadzadeh, R., Zhang, Y.-Y., Stephens, T. E., Arons, E., Zaman, P., Polach, K. J., Matar, M., Yung, L.-M., Yu, P. B., Bowman, F. P., Opotowsky, A. R., Waxman, A. B., Loscalzo, J., Leopold, J. A., Maron, B. A. Up-regulation of the mammalian target of rapamycin complex 1 subunit Raptor by aldosterone induces abnormal pulmonary artery smooth

  19. Regulation of the renin-angiotensin-aldosterone system in fibromyalgia.

    PubMed

    Maliszewski, Anne M; Goldenberg, Don L; Hurwitz, Shelley; Adler, Gail K

    2002-07-01

    To assess the function of the renin-angiotensin-aldosterone (RAA) system in women with fibromyalgia (FM) compared to healthy women. Women with FM [n = 14, age 41.0+/-7.2 yrs, body mass index (BMI) 26.4+/-5.4 kg/m2] and healthy women (n = 13, age 40.0+/-7.7 yrs, BMI 25.0+/-5.0 kg/m2) were placed on a low sodium diet (10 mEq sodium/day) for 5 days. After being supine and fasting overnight, subjects received an intravenous infusion of angiotensin II at successive doses of 1, 3, and 10 ng/kg/min for 45 min per dose. Blood pressure (BP), plasma renin activity (PRA), aldosterone, and cortisol were measured at baseline and after each dose of angiotensin II. Prior to sodium restriction, women with FM completed the Hopkins Symptom Checklist-90, which included a question grading the extent of dizziness/faintness on a scale of 0 (none) to 4 (extremely). After dietary sodium restriction, baseline PRA, aldosterone, and supine BP were similar in healthy women and women with FM. Aldosterone and BP rose in response to infused angiotensin II; these responses did not differ significantly between healthy women and women with FM. In women with FM, symptoms of dizziness correlated inversely with BMI (r = -0.81, p < 0.001) and the systolic BP response to 10 ng/kg/min angiotensin II (r = -0.81, p < 0.001). The functioning of the RAA system, including the vascular response to angiotensin II, was intact in women with FM compared to healthy women. However, women with FM who complained of dizziness had a blunted vascular response to angiotensin II. This blunted vascular response may indicate intravascular volume depletion in women with symptoms of dizziness.

  20. Inducible nitric oxide synthase expression is reduced in cystic fibrosis murine and human airway epithelial cells.

    PubMed Central

    Kelley, T J; Drumm, M L

    1998-01-01

    It has been reported that exhaled nitric oxide levels are reduced in cystic fibrosis (CF) patients. We have examined the inducible isoform of nitric oxide synthase (iNOS) in the airways by immunostaining and found that iNOS is constitutively expressed in the airway epithelia of non-CF mouse and human tissues but essentially absent in the epithelium of CF airways. We explored potential consequences of lost iNOS expression and found that iNOS inhibition significantly increases mouse nasal trans-epithelial potential difference, and hindered the ability of excised mouse lungs to prevent growth of Pseudomonas aeruginosa. The absence of continuous nitric oxide production in epithelial cells of CF airways may play a role in two CF-associated characteristics: hyperabsorption of sodium and susceptibility to bacterial infections. PMID:9739054

  1. Effects of Nitric Oxide Synthase Inhibition on Fiber-Type Composition, Mitochondrial Biogenesis, and SIRT1 Expression in Rat Skeletal Muscle

    PubMed Central

    Suwa, Masataka; Nakano, Hiroshi; Radak, Zsolt; Kumagai, Shuzo

    2015-01-01

    It was hypothesized that nitric oxide synthases (NOS) regulated SIRT1 expression and lead to a corresponding changes of contractile and metabolic properties in skeletal muscle. The purpose of the present study was to investigate the influence of long-term inhibition of nitric oxide synthases (NOS) on the fiber-type composition, metabolic regulators such as and silent information regulator of transcription 1 (SIRT1) and peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), and components of mitochondrial biogenesis in the soleus and plantaris muscles of rats. Rats were assigned to two groups: control and NOS inhibitor (Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME), ingested for 8 weeks in drinking water)-treated groups. The percentage of Type I fibers in the L-NAME group was significantly lower than that in the control group, and the percentage of Type IIA fibers was concomitantly higher in soleus muscle. In plantaris muscle, muscle fiber composition was not altered by L-NAME treatment. L-NAME treatment decreased the cytochrome C protein expression and activity of mitochondrial oxidative enzymes in the plantaris muscle but not in soleus muscle. NOS inhibition reduced the SIRT1 protein expression level in both the soleus and plantaris muscles, whereas it did not affect the PGC-1α protein expression. L-NAME treatment also reduced the glucose transporter 4 protein expression in both muscles. These results suggest that NOS plays a role in maintaining SIRT1 protein expression, muscle fiber composition and components of mitochondrial biogenesis in skeletal muscle. Key points NOS inhibition by L-NAME treatment decreased the SIRT1 protein expression in skeletal muscle. NOS inhibition induced the Type I to Type IIA fiber type transformation in soleus muscle. NOS inhibition reduced the components of mitochondrial biogenesis and glucose metabolism in skeletal muscle. PMID:26336341

  2. Leptin-Aldosterone-Neprilysin Axis: Identification of Its Distinctive Role in the Pathogenesis of the Three Phenotypes of Heart Failure in People With Obesity.

    PubMed

    Packer, Milton

    2018-04-10

    Obesity (especially visceral adiposity) can be associated with 3 different phenotypes of heart failure: heart failure with a reduced ejection fraction, heart failure with a preserved ejection fraction, and high-output heart failure. All 3 phenotypes are characterized by an excessive secretion of aldosterone and sodium retention. In addition, obesity is accompanied by increased signaling through the leptin receptor, which can promote activation of both the sympathetic nervous system and the renin-angiotensin system and can directly stimulate the secretion of aldosterone. The deleterious interaction of leptin and aldosterone is potentiated by the simultaneous action of adiposity and the renal sympathetic nerves to cause overactivity of neprilysin; the loss of the counterbalancing effects of natriuretic peptides is exacerbated by an additional effect of both obesity and heart failure to interfere with adiponectin signaling. This intricate neurohormonal interplay leads to plasma volume expansion as well as to adverse ventricular remodeling and cardiac fibrosis. Furthermore, the activity of aldosterone and neprilysin is not only enhanced by obesity, but these mechanisms can also promote adipogenesis and adipocyte dysfunction, thereby enhancing the positive feedback loop. Last, in elderly obese women, changes in quantity and biology of epicardial adipose tissue further enhances the release of leptin and other proinflammatory adipokines, thereby leading to cardiac and systemic inflammation, end-organ fibrosis, and multiple comorbidities. Regardless of the phenotypic expression, activation of the leptin-aldosterone-neprilysin axis appears to contribute importantly to the evolution and progression of heart failure in people with obesity. Efforts to interfere with the detrimental interactions of this distinctive neurohormonal ecosystem with existing or novel therapeutic agents are likely to yield unique clinical benefits. © 2018 American Heart Association, Inc.

  3. SUMO-fusion, purification, and characterization of a (+)-zizaene synthase from Chrysopogon zizanioides

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hartwig, S.; Frister, T.; Alemdar, S.

    2015-03-20

    An uncharacterized plant cDNA coding for a polypeptide presumably having sesquiterpene synthase activity, was expressed in soluble and active form. Two expression strategies were evaluated in Escherichia coli. The enzyme was fused to a highly soluble SUMO domain, in addition to being produced in an unfused form by a cold-shock expression system. Yields up to ∼325 mg/L{sup −1} were achieved in batch cultivations. The 6x-His-tagged enzyme was purified employing an Ni{sup 2+}-IMAC-based procedure. Identity of the protein was established by Western Blot analysis as well as peptide mass fingerprinting. A molecular mass of 64 kDa and an isoelectric point of pImore » 4.95 were determined by 2D gel electrophoresis. Cleavage of the fusion domain was possible by digestion with specific SUMO protease. The synthase was active in Mg{sup 2+} containing buffer and catalyzed the production of (+)-zizaene (syn. khusimene), a precursor of khusimol, from farnesyl diphosphate. Product identity was confirmed by GC–MS and comparison of retention indices. Enzyme kinetics were determined by measuring initial reaction rates for the product, using varying substrate concentrations. By assuming a Michaelis–Menten model, kinetic parameters of K{sub M} = 1.111 μM (±0.113), v{sub max} = 0.3245 μM min{sup −1} (±0.0035), k{sub cat} = 2.95 min{sup −1}, as well as a catalytic efficiency k{sub cat}/K{sub M} = 4.43 × 10{sup 4} M{sup −1} s{sup −1} were calculated. Fusion to a SUMO moiety can substantially increase soluble expression levels of certain hard to express terpene synthases in E. coli. The kinetic data determined for the recombinant synthase are comparable to other described plant sesquiterpene synthases and in the typical range of enzymes belonging to the secondary metabolism. This leaves potential for optimizing catalytic parameters through methods like directed evolution. - Highlights: • Uncharacterized (+)-zizaene synthase from C. zizanoides was

  4. Air pollution alters brain and pituitary endothelin-1 and inducible nitric oxide synthase gene expression.

    PubMed

    Thomson, Errol M; Kumarathasan, Prem; Calderón-Garcidueñas, Lilian; Vincent, Renaud

    2007-10-01

    Recent work suggests that air pollution is a risk factor for cerebrovascular and neurodegenerative disease. Effects of inhaled pollutants on the production of vasoactive factors such as endothelin (ET) and nitric oxide (NO) in the brain may be relevant to disease pathogenesis. Inhaled pollutants increase circulating levels of ET-1 and ET-3, and the pituitary is a potential source of plasma ET, but the effects of pollutants on the expression of ET and NO synthase genes in the brain and pituitary are not known. In the present study, Fischer-344 rats were exposed by nose-only inhalation to particles (0, 5, 50mg/m3 EHC-93), ozone (0, 0.4, 0.8 ppm), or combinations of particles and ozone for 4 h. Real-time reverse transcription polymerase chain reaction was used to measure mRNA levels in the cerebral hemisphere and pituitary 0 and 24 h post-exposure. Ozone inhalation significantly increased preproET-1 but decreased preproET-3 mRNAs in the cerebral hemisphere, while increasing mRNA levels of preproET-1, preproET-3, and the ET-converting enzyme (ECE)-1 in the pituitary. Inducible NO synthase (iNOS) was initially decreased in the cerebral hemisphere after ozone inhalation, but increased 24 h post-exposure. Particles decreased tumour necrosis factor (TNF)-alpha mRNA in the cerebral hemisphere, and both particles and ozone decreased TNF-alpha mRNA in the pituitary. Our results show that ozone and particulate matter rapidly modulate the expression of genes involved in key vasoregulatory pathways in the brain and pituitary, substantiating the notion that inhaled pollutants induce cerebrovascular effects.

  5. Predictors of hyperkalemia risk following hypertension control with aldosterone blockade.

    PubMed

    Khosla, Nitin; Kalaitzidis, Rigas; Bakris, George L

    2009-01-01

    Aldosterone antagonists have proven efficacy for management of resistant hypertension and proteinuria reduction; however, they are not widely used due to risk of hyperkalemia. This study assesses the risk factors for hyperkalemia in patients with chronic kidney disease (CKD) and resistant hypertension whose blood pressure (BP) is reduced to a guideline goal. This is a two-center study conducted in university-based hypertension clinics directed by clinical hypertension specialists. Forty-six patients with resistant hypertension and stages 2 or 3 CKD (mean estimated glomerular filtration rate (eGFR) 56.5 + or - 16.2 ml/min/1.73 m(2)) were evaluated for safety and efficacy of aldosterone blockade added to preexisting BP-lowering regimens. All patients were on three mechanistically complementary antihypertensive agents including a diuretic and a renin-angiotensin system blocker. Patients were evaluated after a median of 45 treatment days. The primary endpoint was change in systolic BP. Secondary endpoints included change in serum potassium, creatinine, eGFR, diastolic BP and tolerability. The mean age of the patients studied was 64.9 + or - 10.7 years, all were obese and 86% had type 2 diabetes, with 82% being African-American. Addition of aldosterone antagonism yielded a further mean reduction in systolic BP of 14.7 + or - 5.1 mm Hg (p = 0.001). Females with BMI >30 and those with a baseline systolic BP >160 mm Hg were more likely to have a greater BP reduction to aldosterone antagonism. In total, 39% of the patients had a >30% decrease in eGFR when the BP goal was achieved. The mean increase in serum potassium was 0.4 mEq/l above baseline (p = 0.001), with 17.3% manifesting hyperkalemia, i.e. serum potassium >5.5 mEq/l. Predictors of hyperkalemia included a baseline eGFR of < or = 45 ml/min/1.73 m(2) in whom serum potassium was >4.5 mEq/l on appropriately dosed diuretics. Contributing risks in this subgroup included a systolic BP reduction of >15 mm Hg associated

  6. Developmental evolution of flowering plant pollen tube cell walls: callose synthase (CalS) gene expression patterns

    PubMed Central

    2011-01-01

    Background A number of innovations underlie the origin of rapid reproductive cycles in angiosperms. A critical early step involved the modification of an ancestrally short and slow-growing pollen tube for faster and longer distance transport of sperm to egg. Associated with this shift are the predominantly callose (1,3-β-glucan) walls and septae (callose plugs) of angiosperm pollen tubes. Callose synthesis is mediated by callose synthase (CalS). Of 12 CalS gene family members in Arabidopsis, only one (CalS5) has been directly linked to pollen tube callose. CalS5 orthologues are present in several monocot and eudicot genomes, but little is known about the evolutionary origin of CalS5 or what its ancestral function may have been. Results We investigated expression of CalS in pollen and pollen tubes of selected non-flowering seed plants (gymnosperms) and angiosperms within lineages that diverged below the monocot/eudicot node. First, we determined the nearly full length coding sequence of a CalS5 orthologue from Cabomba caroliniana (CcCalS5) (Nymphaeales). Semi-quantitative RT-PCR demonstrated low CcCalS5 expression within several vegetative tissues, but strong expression in mature pollen. CalS transcripts were detected in pollen tubes of several species within Nymphaeales and Austrobaileyales, and comparative analyses with a phylogenetically diverse group of sequenced genomes indicated homology to CalS5. We also report in silico evidence of a putative CalS5 orthologue from Amborella. Among gymnosperms, CalS5 transcripts were recovered from germinating pollen of Gnetum and Ginkgo, but a novel CalS paralog was instead amplified from germinating pollen of Pinus taeda. Conclusion The finding that CalS5 is the predominant callose synthase in pollen tubes of both early-diverging and model system angiosperms is an indicator of the homology of their novel callosic pollen tube walls and callose plugs. The data suggest that CalS5 had transient expression and pollen

  7. [Pathophysiological role of tissue renin-angiotensin-aldosterone system (RAAS) in human atherosclerosis].

    PubMed

    Fukui, Kensuke; Yamada, Hiroyuki; Matsubara, Hiroaki

    2012-09-01

    Renin-angiotensin-aldosterone system (RAAS) has been demonstrated to play an important role in the pathogenesis of atherosclerosis development both in animal experiments and in clinical studies. Numerous clinical studies have shown that blockade of RAAS exerts beneficial effects to restore the impaired endothelial function and to reduce the mortality and morbidity of cardiovascular diseases beyond their blood pressure lowering effect. However, the underlying mechanisms of stabilizing vulnerable plaque and inhibiting plaque rupture associated with acute coronary syndrome have not yet been fully elucidated. Here, we summarized the characteristics of tissue RAAS expressions in human atherosclerotic lesions and assessed their therapeutic relevance in the prevention of atherosclerotic cardiovascular diseases.

  8. Isoprene synthase genes form a monophyletic clade of acyclic terpene synthases in the TPS-B terpene synthase family.

    PubMed

    Sharkey, Thomas D; Gray, Dennis W; Pell, Heather K; Breneman, Steven R; Topper, Lauren

    2013-04-01

    Many plants emit significant amounts of isoprene, which is hypothesized to help leaves tolerate short episodes of high temperature. Isoprene emission is found in all major groups of land plants including mosses, ferns, gymnosperms, and angiosperms; however, within these groups isoprene emission is variable. The patchy distribution of isoprene emission implies an evolutionary pattern characterized by many origins or many losses. To better understand the evolution of isoprene emission, we examine the phylogenetic relationships among isoprene synthase and monoterpene synthase genes in the angiosperms. In this study we identify nine new isoprene synthases within the rosid angiosperms. We also document the capacity of a myrcene synthase in Humulus lupulus to produce isoprene. Isoprene synthases and (E)-β-ocimene synthases form a monophyletic group within the Tps-b clade of terpene synthases. No asterid genes fall within this clade. The chemistry of isoprene synthase and ocimene synthase is similar and likely affects the apparent relationships among Tps-b enzymes. The chronology of rosid evolution suggests a Cretaceous origin followed by many losses of isoprene synthase over the course of evolutionary history. The phylogenetic pattern of Tps-b genes indicates that isoprene emission from non-rosid angiosperms likely arose independently. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  9. In vivo inhibition of the mitochondrial H+-ATP synthase in neurons promotes metabolic preconditioning.

    PubMed

    Formentini, Laura; Pereira, Marta P; Sánchez-Cenizo, Laura; Santacatterina, Fulvio; Lucas, José J; Navarro, Carmen; Martínez-Serrano, Alberto; Cuezva, José M

    2014-04-01

    A key transducer in energy conservation and signaling cell death is the mitochondrial H(+)-ATP synthase. The expression of the ATPase inhibitory factor 1 (IF1) is a strategy used by cancer cells to inhibit the activity of the H(+)-ATP synthase to generate a ROS signal that switches on cellular programs of survival. We have generated a mouse model expressing a mutant of human IF1 in brain neurons to assess the role of the H(+)-ATP synthase in cell death in vivo. The expression of hIF1 inhibits the activity of oxidative phosphorylation and mediates the shift of neurons to an enhanced aerobic glycolysis. Metabolic reprogramming induces brain preconditioning affording protection against quinolinic acid-induced excitotoxicity. Mechanistically, preconditioning involves the activation of the Akt/p70S6K and PARP repair pathways and Bcl-xL protection from cell death. Overall, our findings provide the first in vivo evidence highlighting the H(+)-ATP synthase as a target to prevent neuronal cell death.

  10. Pu-erh Tea Reduces Nitric Oxide Levels in Rats by Inhibiting Inducible Nitric Oxide Synthase Expression through Toll-Like Receptor 4

    PubMed Central

    Xu, Yang; Wang, Guan; Li, Chunjie; Zhang, Min; Zhao, Hang; Sheng, Jun; Shi, Wei

    2012-01-01

    Pu-erh tea undergoes a unique fermentation process and contains theabrownins, polysaccharides and caffeine; although it is unclear about which component is associated with the down regulation of nitric oxide levels or how this process is mediated. To address this question we examined the effects of pu-erh tea on nitric oxide synthase (NOS) genes. Cohorts of rats were separately given four-week treatments of water as control, pu-erh tea, or the tea components: theabrownins, caffeine or polysaccharides. Five experimental groups were injected with lipopolysaccharides (LPS) to induce nitric oxide (NO) production, while the corresponding five control groups were injected with saline as a negative control. The serum and liver NO concentrations were examined and the NOS expression of both mRNA and protein was measured in liver. The results showed that the rats which were fed pu-erh tea or polysaccharides had lower levels of NO which corresponded with the down-regulation of inducible nitric oxide synthase (iNOS) expression. We further demonstrate that this effect is mediated through reduction of Toll-like receptor 4 (TLR4) signaling. Thus we find that the polysaccharide components in pu-erh tea reduce NO levels in an animal model by inhibiting the iNOS expression via signaling through TLR4. PMID:22837686

  11. Aldosterone Does Not Predict Cardiovascular Events Following Acute Coronary Syndrome in Patients Initially Without Heart Failure.

    PubMed

    Pitts, Reynaria; Gunzburger, Elise; Ballantyne, Christie M; Barter, Philip J; Kallend, David; Leiter, Lawrence A; Leitersdorf, Eran; Nicholls, Stephen J; Shah, Prediman K; Tardif, Jean-Claude; Olsson, Anders G; McMurray, John J V; Kittelson, John; Schwartz, Gregory G

    2017-01-10

    Aldosterone may have adverse effects in the myocardium and vasculature. Treatment with an aldosterone antagonist reduces cardiovascular risk in patients with acute myocardial infarction complicated by heart failure (HF) and left ventricular systolic dysfunction. However, most patients with acute coronary syndrome do not have advanced HF. Among such patients, it is unknown whether aldosterone predicts cardiovascular risk. To address this question, we examined data from the dal-OUTCOMES trial that compared the cholesteryl ester transfer protein inhibitor dalcetrapib with placebo, beginning 4 to 12 weeks after an index acute coronary syndrome. Patients with New York Heart Association class II (with LVEF <40%), III, or IV HF were excluded. Aldosterone was measured at randomization in 4073 patients. The primary outcome was a composite of coronary heart disease death, nonfatal myocardial infarction, stroke, hospitalization for unstable angina, or resuscitated cardiac arrest. Hospitalization for HF was a secondary endpoint. Over a median follow-up of 37 months, the primary outcome occurred in 366 patients (9.0%), and hospitalization for HF occurred in 72 patients (1.8%). There was no association between aldosterone and either the time to first occurrence of a primary outcome (hazard ratio for doubling of aldosterone 0.92, 95% confidence interval 0.78-1.09, P=0.34) or hospitalization for HF (hazard ratio 1.38, 95% CI 0.96-1.99, P=0.08) in Cox regression models adjusted for covariates. In patients with recent acute coronary syndrome but without advanced HF, aldosterone does not predict major cardiovascular events. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00658515. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  12. 21 CFR 862.1045 - Aldosterone test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Aldosterone test system. 862.1045 Section 862.1045 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862...

  13. 21 CFR 862.1045 - Aldosterone test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Aldosterone test system. 862.1045 Section 862.1045 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862...

  14. 21 CFR 862.1045 - Aldosterone test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Aldosterone test system. 862.1045 Section 862.1045 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862...

  15. 21 CFR 862.1045 - Aldosterone test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Aldosterone test system. 862.1045 Section 862.1045 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862...

  16. 21 CFR 862.1045 - Aldosterone test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Aldosterone test system. 862.1045 Section 862.1045 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry Test Systems § 862...

  17. Pathophysiology and Treatment of Resistant Hypertension: The Role of Aldosterone and Amiloride-Sensitive Sodium Channels

    PubMed Central

    Judd, Eric K.; Calhoun, David A.; Warnock, David G.

    2015-01-01

    Summary Resistant hypertension is a clinically distinct subgroup of hypertension defined by the failure to achieve blood pressure control on optimal dosing of at least 3 antihypertensive medications of different classes, including a diuretic. The pathophysiology of hypertension can be attributed to aldosterone excess in more than 20% of patients with resistant hypertension. Existing dogma attributes the increase in blood pressure seen with increases in aldosterone to its antinatriuretic effects in the distal nephron. However, emerging research, which has identified and has begun to define the function of amiloride-sensitive sodium channels and mineralocorticoid receptors in the systemic vasculature, challenges impaired natriuresis as the sole cause of aldosterone-mediated resistant hypertension. This review integrates these findings to better define the role of the vasculature and aldosterone in the pathophysiology of resistant hypertension. In addition, a brief guide to the treatment of resistant hypertension is presented. PMID:25416662

  18. Pathophysiology and treatment of resistant hypertension: the role of aldosterone and amiloride-sensitive sodium channels.

    PubMed

    Judd, Eric K; Calhoun, David A; Warnock, David G

    2014-01-01

    Resistant hypertension is a clinically distinct subgroup of hypertension defined by the failure to achieve blood pressure control on optimal dosing of at least 3 antihypertensive medications of different classes, including a diuretic. The pathophysiology of hypertension can be attributed to aldosterone excess in more than 20% of patients with resistant hypertension. Existing dogma attributes the increase in blood pressure seen with increases in aldosterone to its antinatriuretic effects in the distal nephron. However, emerging research, which has identified and has begun to define the function of amiloride-sensitive sodium channels and mineralocorticoid receptors in the systemic vasculature, challenges impaired natriuresis as the sole cause of aldosterone-mediated resistant hypertension. This review integrates these findings to better define the role of the vasculature and aldosterone in the pathophysiology of resistant hypertension. In addition, a brief guide to the treatment of resistant hypertension is presented.

  19. Captopril suppression: limitations for confirmation of primary aldosteronism.

    PubMed

    Westerdahl, Christina; Bergenfelz, Anders; Isaksson, Anders; Valdemarsson, Stig

    2011-09-01

    The aldosterone/renin ratio (ARR) is the first line screening test for primary aldosteronism (PA). However, in hypertensive patients with an increased ARR, PA needs to be confirmed by other means. A 25 mg oral captopril test was performed in 16 healthy subjects to obtain reference values for aldosterone and ARR at 120 minutes after the test. Subsequently these data were applied to 46 hypertensive patients screened for PA with an increased ARR. At 120 minutes after the captopril test ARR decreased in healthy subjects within a narrow range, but remained high in patients with PA and in patients with primary hypertension, especially for those with low renin characteristics. At 120 minutes after captopril, the range of ARR in primary hypertensive patients overlapped in 88% of the cases with the range of the ARR in the PA patients. Sensitivity and specificity of basal ARR and ARR after the captopril test to diagnose PA, calculated as receiver operator characteristics, showed an area under the curve of 0.595 for basal ARR and 0.664 for ARR at 120 minutes after the test. The ARR at 120 minutes after the captopril test is only marginally better than basal ARR in diagnosing PA in hypertensive patients screened with an increased ARR. Owing to an overall limited capacity to clearly discriminate PA from primary hypertension, the test could not therefore be recommended for the confirmatory diagnosis of PA.

  20. Prostaglandin G/H synthase (PGHS)-2 expression in bovine myometrium: influence of steroid hormones and PGHS inhibitors.

    PubMed

    Doualla-Bell, F; Guay, J M; Bourgoin, S; Fortier, M A

    1998-12-01

    Prostaglandins (PGs) are important mediators regulating uterine functions during the reproductive process. The objective of this study was to examine, in myocytes from the circular and longitudinal layers of bovine myometrium, the relative levels of mRNA and proteins corresponding to the gene expression of key enzymes (phospholipase A2; prostaglandin G/H synthase-1 [PGHS-1]; prostaglandin G/H synthase-2 [PGHS-2]; prostaglandin I2 synthase) involved in PG biosynthesis. We examined the influence of estradiol-17beta and progesterone on the expression and activity of these enzymes. Treatment of myocytes with progesterone (P4: 10 nM, 24 h) in the absence or presence of estradiol-17beta (E2: 1 nM, 72 h) suppressed PG biosynthesis by approximately 60% in both myometrial layers. No significant effect was observed after E2 treatment. The combined effect of E2 and P4 on PG accumulation was correlated with the modulation of PGHS-2 protein and mRNA levels in the two myometrial layers without affecting other enzymes of the PG cascade. Selective or nonselective inhibition of PGHS activity with CGP 28238 (PGHS-2-specific; a product from Ciba-Geigy: 6-[2, 4-difluorophenoxy]-5-methyl-sulfonylamino-1-indanone) or indomethacin (PGHS-1 and -2) reduced prostacyclin accumulation (measured as 6-keto-PGF1alpha in the culture medium) in a dose-dependent manner in the two myometrial layers. A significant inhibitory effect was obtained at a low concentration of indomethacin (1 nM, p < 0.05) compared to CGP 28238 (10 nM, p < 0. 05). In both myometrial layers, the maximal effect of indomethacin and/or CGP 28238 on PG accumulation was observed at 100 nM and represented 85% and 65% inhibition, respectively. In the presence of phorbol 12-myristate (100 nM), CGP 28238 (10 nM) significantly suppressed PGHS-2 mRNA level by 44.80 +/- 7.67% (p < 0.01) and 27.83 +/- 7.62% (p < 0.05) in the longitudinal and circular layer, respectively. In contrast, indomethacin did not have any significant effect

  1. Relation of dietary salt and aldosterone to urinary protein excretion in subjects with resistant hypertension.

    PubMed

    Pimenta, Eduardo; Gaddam, Krishna K; Pratt-Ubunama, Monique N; Nishizaka, Mari K; Aban, Inmaculada; Oparil, Suzanne; Calhoun, David A

    2008-02-01

    Experimental data indicate that the cardiorenal effects of aldosterone excess are dependent on concomitant high dietary salt intake. Such an interaction of endogenous aldosterone and dietary salt has not been observed previously in humans. We assessed the hypothesis that excess aldosterone and high dietary sodium intake combine to worsen proteinuria in patients with resistant hypertension. Consecutive subjects with resistant hypertension (n=84) were prospectively evaluated by measurement of 24-hour urinary aldosterone (Ualdo), sodium, and protein (Uprot) excretion. Subjects were analyzed according to aldosterone status (high: Ualdo >or=12 microg/24 hours; or normal: <12 microg/24 hours) and dietary salt intake based on tertiles of urinary sodium. The mean clinic blood pressure for all of the subjects was 161.4+/-22.4/89.8+/-13.5 mm Hg on an average of 4.3 medications. There was no blood pressure difference between study groups. Uprot was significantly higher in the 38 subjects with high Ualdo compared with the 46 subjects with normal Ualdo (143.0+/-83.8 versus 95.9+/-81.7 mg/24 hours; P=0.01). Among subjects with high Ualdo, Uprot increased progressively across urinary sodium groups (P<0.05). In contrast, there was no difference in Uprot across sodium tertiles among subjects with normal Ualdo. A positive correlation between Uprot and urinary sodium (r=0.47; P=0.003) was observed in subjects with high Ualdo but not in subjects with normal Ualdo (r=0.18; P value not significant). These results suggest that aldosterone excess and high dietary salt combine to increase urinary protein excretion.

  2. Mitochondrial F1Fo-ATP synthase translocates to cell surface in hepatocytes and has high activity in tumor-like acidic and hypoxic environment.

    PubMed

    Ma, Zhan; Cao, Manlin; Liu, Yiwen; He, Yiqing; Wang, Yingzhi; Yang, Cuixia; Wang, Wenjuan; Du, Yan; Zhou, Muqing; Gao, Feng

    2010-08-01

    F1Fo-ATP synthase was originally thought to exclusively locate in the inner membrane of the mitochondria. However, recent studies prove the existence of ectopic F1Fo-ATP synthase on the outside of the cell membrane. Ectopic ATP synthase was proposed as a marker for tumor target therapy. Nevertheless, the protein transport mechanism of the ectopic ATP synthase is still unclear. The specificity of the ectopic ATP synthase, with regard to tumors, is questioned because of its widespread expression. In the current study, we constructed green fluorescent protein-ATP5B fusion protein and introduced it into HepG2 cells to study the localization of the ATP synthase. The expression of ATP5B was analyzed in six cell lines with different 'malignancies'. These cells were cultured in both normal and tumor-like acidic and hypoxic conditions. The results suggested that the ectopic expression of ATP synthase is a consequence of translocation from the mitochondria. The expression and catalytic activity of ectopic ATP synthase were similar on the surface of malignant cells as on the surface of less malignant cells. Interestingly, the expression of ectopic ATP synthase was not up-regulated in tumor-like acidic and hypoxic microenvironments. However, the catalytic activity of ectopic ATP synthase was up-regulated in tumor-like microenvironments. Therefore, the specificity of ectopic ATP synthase for tumor target therapy relies on the high level of catalytic activity that is observed in acidic and hypoxic microenvironments in tumor tissues.

  3. Aldosterone and glomerular filtration – observations in the general population

    PubMed Central

    2014-01-01

    Background Increasing evidence suggests that aldosterone promotes renal damage. Since data on the association between aldosterone and renal function in the general population are sparse, we chose to address this issue. We investigated the associations between the plasma aldosterone concentration (PAC) or the aldosterone-to-renin ratio (ARR) and the estimated glomerular filtration rate (eGFR) in a sample of adult men and women from Northeast Germany. Methods A study population of 1921 adult men and women who participated in the first follow-up of the Study of Health in Pomerania was selected. None of the subjects used drugs that alter PAC or ARR. The eGFR was calculated according to the four-variable Modification of Diet in Renal Disease formula. Chronic kidney disease (CKD) was defined as an eGFR <60 ml/min/1.73 m2. Results Linear regression models, adjusted for sex, age, waist circumference, diabetes mellitus, smoking status, systolic and diastolic blood pressures, serum triglyceride concentrations and time of blood sampling revealed inverse associations of PAC or ARR with eGFR (ß-coefficient for log-transformed PAC −3.12, p < 0.001; ß-coefficient for log-transformed ARR −3.36, p < 0.001). Logistic regression models revealed increased odds for CKD with increasing PAC (odds ratio for a one standard deviation increase in PAC: 1.35, 95% confidence interval: 1.06-1.71). There was no statistically significant association between ARR and CKD. Conclusion Our study demonstrates that PAC and ARR are inversely associated with the glomerular filtration rate in the general population. PMID:24612948

  4. Preoperative Plasma Aldosterone Levels and Postoperative Atrial Fibrillation Occurrence Following Cardiac Surgery: A Review of Literature and Design of the ALDO-POAF Study (ALDOsterone for Prediction of Post-Operative Atrial Fibrillation).

    PubMed

    Chequel, Mathieu; Ollitrault, Pierre; Saloux, Eric; Parienti, Jean-Jacques; Fischer, Marc-Olivier; Desgué, Julien; Allouche, Stéphane; Milliez, Paul; Alexandre, Joachim

    2016-01-01

    Post-operative atrial fibrillation (POAF) is a major and frequent complication occurring after cardiac surgery, contributing to prolonged intensive care and hospital stays and is associated with several cardiovascular complications. The exact mechanisms and signaling pathways involved in the development of POAF seem to be multifactorial and remain to date incompletely understood. β-blockers and amiodarone are the first line preventive drugs but are partially effective and near 30% of POAF resist to these strategies. In this work, we review the current knowledge about pathophysiological POAF mechanisms and preventive pharmacological strategies. We also discuss the rational for the use of pre-operative plasma aldosterone and galectin-3 (Gal-3) levels as predictive biomarkers of POAF and the potential role of aldosterone antagonists in the POAF preventive strategy. POAF is a major complication occurring after cardiac surgery. In this context, there is some evidence indicating that renin-angiotensin-aldosterone system and Gal-3 could be very useful predictive biomarkers of POAF and potentially interesting therapeutic target to prevent POAF occurrence. We present the rationale and the design of the ALDO-POAF trial (ALDOsterone for prediction of Post- Operative Atrial Fibrillation, NCT 02814903).

  5. Expression and prognostic significance of thymidylate synthase (TS) in pancreatic head and periampullary cancer.

    PubMed

    van der Zee, J A; van Eijck, C H J; Hop, W C J; van Dekken, H; Dicheva, B M; Seynhaeve, A L B; Koning, G A; Eggermont, A M M; Ten Hagen, T L M

    2012-11-01

    Pancreatic cancer has a dismal prognosis. Attempts have been made to improve outcome by several 5-FU based adjuvant treatment regimens. However, the results are conflicting. There seems to be a continental divide with respect to the use of 5-FU based chemoradiotherapy (CRT). Furthermore, evidence has been presented showing a different response of pancreatic head and periampullary cancer to 5-FU based CRT. Expression of thymidylate synthase (TS) has been associated with improved outcome following 5-FU based adjuvant treatment in gastrointestinal cancer. This prompted us to determine the differential expression and prognostic value of TS in pancreatic head and periampullary cancer. TS protein expression was studied by immunohistochemistry on original paraffin embedded tissue from 212 patients following microscopic radical resection (R0) of pancreatic head (n = 98) or periampullary cancer (n = 114). Expression was investigated for associations with recurrence free (RFS), cancer specific (CSS) and overall survival (OS), and conventional prognostic factors. High cytosolic TS expression was present in 26% of pancreatic head tumours and 37% of periampullary tumours (p = .11). Furthermore, TS was an independent factor predicting favourable outcome following curative resection of pancreatic head cancer (p = .003, .001 and .001 for RFS, CSS and OS, respectively). In contrast, in periampullary cancer, TS was not associated with outcome (all p > .10). TS, was found to be poorly expressed in both pancreatic head and periampullary cancer and identified as an independent prognostic factor following curative resection of pancreatic head cancer. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Effect of bedrest on circadian rhythms of plasma renin, aldosterone, and cortisol

    NASA Technical Reports Server (NTRS)

    Chavarri, M.; Ganguly, A.; Luetscher, J. A.; Zager, P. G.

    1977-01-01

    Previous studies of normal men after 5 d of bedrest showed that circulatory instability on head-up tilt or standing is preceded by increased plasma renin activity (PRA) at bedrest. In the present study, the circadian rhythms of PRA, aldosterone, and cortisol have been observed in five normal men on a constant diet. In ambulatory controls, PRA and aldosterone increased normally after standing. On the third morning of bedrest, PRA was higher than before, and at noon, PRA was higher than in standing controls. The nocturnal peaks of PRA resulting from episodic renin secretion during sleep were higher after bedrest. Plasma aldosterone was also increased by bedrest. The findings are compatible with the theory that intermittent beta-adrenergic nerve activity during sleep is increased after bedrest, but other factors, such as loss of body sodium and a lower plasma volume, may also be involved.

  7. NADPH-diaphorase activity and NO synthase expression in the olfactory epithelium of the bovine.

    PubMed

    Wenisch, S; Arnhold, S

    2010-06-01

    NADPH-diaphorase (NADPH-d) staining of the bovine olfactory epithelium was compared with the immunohistochemical localization of nitric oxide synthase (NOS), soluble guanylyl cyclase, and cGMP (cyclic guanosine 3',5'-monophosphate). Out of the three isoforms, only the inducible NOS (NOS-II) was found at the epithelial surface correlating with the strong labelling for NADPH-d. In contrast, light diaphorase staining associated with deeper epithelial regions did not coincide with any NOS immunoreactivity. As there is overlapping expression of NOS-II, soluble guanylyl cyclase and cGMP at the luminal surface morphologically occupied by dendritic knobs of olfactory receptor neurons and microvillar endings of supporting cells, the nitric oxide (NO)/cGMP pathway is likely to be involved in modulating the odour signals during olfactory transduction.

  8. Sodium-bicarbonated mineral water decreases aldosterone levels without affecting urinary excretion of bone minerals.

    PubMed

    Schoppen, Stefanie; Pérez-Granados, Ana M; Carbajal, Angeles; Sarriá, Beatriz; Navas-Carretero, Santiago; Pilar Vaquero, M

    2008-06-01

    AIM To assess in healthy postmenopausal women the influence of consuming sodium-bicarbonated mineral water on postprandial evolution of serum aldosterone and urinary electrolyte excretion. Eighteen postmenopausal women consumed 500 ml of two sodium-bicarbonated mineral waters (sodium-bicarbonated mineral water 1 and sodium-bicarbonated mineral water 2) and a low-mineral water with a standard meal. Postprandial blood samples were taken at 60, 120, 240, 360 and 420 min and aldosterone concentrations were measured. Postprandial urinary minerals were determined. Urinary and total mineral excretion and urinary mineral concentrations did not differ except for sodium concentration, which was significantly higher with sodium-bicarbonated mineral water 1 than with low-mineral water (P = 0.005). There was a time effect (P = 0.003) on the aldosterone concentration. At 120 min, aldosterone concentrations were lower with sodium-bicarbonated mineral water 1 (P = 0.021) and sodium-bicarbonated mineral water 2 (P = 0.030) compared with low-mineral water. Drinking a sodium-rich bicarbonated mineral water with a meal increases urinary sodium concentration excretion without changes in the excretion of potassium and bone minerals.

  9. Plasticity and evolution of (+)-3-carene synthase and (-)-sabinene synthase functions of a sitka spruce monoterpene synthase gene family associated with weevil resistance.

    PubMed

    Roach, Christopher R; Hall, Dawn E; Zerbe, Philipp; Bohlmann, Jörg

    2014-08-22

    The monoterpene (+)-3-carene is associated with resistance of Sitka spruce against white pine weevil, a major North American forest insect pest of pine and spruce. High and low levels of (+)-3-carene in, respectively, resistant and susceptible Sitka spruce genotypes are due to variation of (+)-3-carene synthase gene copy number, transcript and protein expression levels, enzyme product profiles, and enzyme catalytic efficiency. A family of multiproduct (+)-3-carene synthase-like genes of Sitka spruce include the three (+)-3-carene synthases, PsTPS-3car1, PsTPS-3car2, PsTPS-3car3, and the (-)-sabinene synthase PsTPS-sab. Of these, PsTPS-3car2 is responsible for the relatively higher levels of (+)-3-carene in weevil-resistant trees. Here, we identified features of the PsTPS-3car1, PsTPS-3car2, PsTPS-3car3, and PsTPS-sab proteins that determine different product profiles. A series of domain swap and site-directed mutations, supported by structural comparisons, identified the amino acid in position 596 as critical for product profiles dominated by (+)-3-carene in PsTPS-3car1, PsTPS-3car2, and PsTPS-3car3, or (-)-sabinene in PsTPS-sab. A leucine in this position promotes formation of (+)-3-carene, whereas phenylalanine promotes (-)-sabinene. Homology modeling predicts that position 596 directs product profiles through differential stabilization of the reaction intermediate. Kinetic analysis revealed position 596 also plays a role in catalytic efficiency. Mutations of position 596 with different side chain properties resulted in a series of enzymes with different product profiles, further highlighting the inherent plasticity and potential for evolution of alternative product profiles of these monoterpene synthases of conifer defense against insects. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Angiotensin 1-7 Is a Negative Modulator of Aldosterone Secretion In Vitro and In Vivo.

    PubMed

    Shefer, Gabi; Marcus, Yonit; Knoll, Esther; Dolkart, Oleg; Foichtwanger, Shulamit; Nevo, Nava; Limor, Rona; Stern, Naftali

    2016-08-01

    Angiotensin (1-7) [Ang 1-7] is a 7 amino acid peptide generated predominantly from Ang II by the action of Ang-converting enzyme 2. We previously showed that Ang 1-7 reduced plasma aldosterone and plasma renin activity in high fructose-fed rats, and that the reduction in circulating aldosterone seemed to accord a parallel reduction in plasma renin activity. Here, we tested the possibility that Ang 1-7 affects aldosterone secretion acting directly in glomerulosa cells. First, as detected by immunofluorescence, the receptor for Ang 1-7, Mas1 is localized predominantly at the rat adrenal subcapsular region. Second, in isolated rat glomerulosa cells incubates, Ang 1-7 attenuated the aldosterone response to Ang II, with the strongest effect seen on Ang II (10(-9) M) (control 22±2.5 pg/10(5) cells; Ang II [10(-9) M] 189±11 pg/10(5) cells; Ang II [10(-9) M]+Ang 1-7 [10(-6) M] 33±3.6 pg/10(5) cells; P<0.001) and the largest effect on adrenocorticotropic hormone (10(-8) M) (control 30±3.4 pg/10(5) cells; ACTH [10(-8) M] 409±32.5 pg/10(5) cells; ACTH [10(-8) M]+Ang 1-7 [10(-6) M] 280±12.5 pg/10(5) cells; P<0.001). In contrast, Ang 1-7 did not affect the aldosterone response to potassium (K(+)). In rats subjected to a low-salt diet for 7 days, continuous infusion of Ang 1-7 (576 μg/kg per day) resulted in a lesser rise in aldosterone (salt deplete+Ang 1-7, 16.4±4.8 ng/dL) compared with rats receiving vehicle (salt deplete+vehicle, 27.6±5.3 ng/dL; P<0.01) but did not modify plasma renin activity. Taken together, these results indicate that Ang 1-7 can act as a negative modulator of aldosterone secretion in vitro and in vivo. © 2016 American Heart Association, Inc.

  11. Optimization of thermophilic trans-isoprenyl diphosphate synthase expression in Escherichia coli by response surface methodology.

    PubMed

    Piccolomini, Angelica A; Fiabon, Alex; Borrotti, Matteo; De Lucrezia, Davide

    2017-01-01

    We optimized the heterologous expression of trans-isoprenyl diphosphate synthase (IDS), the key enzyme involved in the biosynthesis of trans-polyisoprene. trans-Polyisoprene is a particularly valuable compound due to its superior stiffness, excellent insulation, and low thermal expansion coefficient. Currently, trans-polyisoprene is mainly produced through chemical synthesis and no biotechnological processes have been established so far for its large-scale production. In this work, we employed D-optimal design and response surface methodology to optimize the expression of thermophilic enzymes IDS from Thermococcus kodakaraensis. The design of experiment took into account of six factors (preinduction cell density, inducer concentration, postinduction temperature, salt concentration, alternative carbon source, and protein inhibitor) and seven culture media (LB, NZCYM, TB, M9, Ec, Ac, and EDAVIS) at five different pH points. By screening only 109 experimental points, we were able to improve IDS production by 48% in close-batch fermentation. © 2015 International Union of Biochemistry and Molecular Biology, Inc.

  12. In-Situ Biocatalytic Production of Trehalose with Autoinduction Expression of Trehalose Synthase.

    PubMed

    Yan, Xincheng; Zhu, Liying; Yu, Yadong; Xu, Qing; Huang, He; Jiang, Ling

    2018-02-14

    We developed an in-situ biocatalytic process that couples autoinduction expression of trehalose synthase (TreS) and whole-cell catalysis for trehalose production. With lactose as the autoinducer, the activity of recombinant TreS in recombinant Escherichia coli was optimized through a visualization method, which resulted in a maximum value of 12 033 ± 730 U/mL in pH-stat fed-batch fermentation mode. Meanwhile, the permeability of the autoinduced E. coli increased significantly, which makes it possible to be directly used as a whole-cell biocatalyst for trehalose production, whereby the byproduct glucose can also act as an extra carbon source. In this case, the final yield of trehalose was improved to 90.5 ± 5.7% and remained as high as 83.2 ± 5.0% at the 10th batch, which is the highest value achieved using recombinant TreS. Finally, an integrated strategy for trehalose production was established, and its advantages compared to the traditional mode have been summarized.

  13. Primary aldosteronism and thyroid disorders in atrial fibrillation: A Swedish nationwide case-control study.

    PubMed

    Mourtzinis, Georgios; Adamsson Eryd, Samuel; Rosengren, Annika; Björck, Lena; Adiels, Martin; Johannsson, Gudmundur; Manhem, Karin

    2018-05-01

    Background Atrial fibrillation is associated with hyperthyroidism. Patients with primary aldosteronism have an increased prevalence of atrial fibrillation. However, the prevalence of primary aldosteronism in the atrial fibrillation population is unknown. Aim This nationwide case-control study aimed to compare the prevalence of primary aldosteronism and thyroid disorders in patients with atrial fibrillation with that of age- and sex-matched controls. Methods We identified all atrial fibrillation cases in Sweden between 1987 and 2013 ( n = 713,569) by using the Swedish National Patient Register. A control cohort without atrial fibrillation was randomly selected from the Swedish Total Population Register with a case to control ratio of 1:2. This control cohort was matched for age, sex and place of birth ( n = 1,393,953). Results The prevalence of primary aldosteronism in December 2013 was 0.056% in the atrial fibrillation cohort and 0.024% in controls. At the same time, the prevalence of hypothyroidism was 5.9% in the atrial fibrillation cohort and 3.7% in controls. The prevalence of hyperthyroidism was 2.3% in the atrial fibrillation cohort and 0.8% in controls. Conclusion This study shows, for the first time, a doubled prevalence of primary aldosteronism in a large cohort of patients with atrial fibrillation compared with the general population. There is also an increased prevalence of hypo- and hyper-thyroidism in patients with atrial fibrillation compared with the general population.

  14. Thymidylate synthase (TS) gene expression in primary lung cancer patients: a large-scale study in Japanese population.

    PubMed

    Tanaka, F; Wada, H; Fukui, Y; Fukushima, M

    2011-08-01

    Previous small-sized studies showed lower thymidylate synthase (TS) expression in adenocarcinoma of the lung, which may explain higher antitumor activity of TS-inhibiting agents such as pemetrexed. To quantitatively measure TS gene expression in a large-scale Japanese population (n = 2621) with primary lung cancer, laser-captured microdissected sections were cut from primary tumors, surrounding normal lung tissues and involved nodes. TS gene expression level in primary tumor was significantly higher than that in normal lung tissue (mean TS/β-actin, 3.4 and 1.0, respectively; P < 0.01), and TS gene expression level was further higher in involved node (mean TS/β-actin, 7.7; P < 0.01). Analyses of TS gene expression levels in primary tumor according to histologic cell type revealed that small-cell carcinoma showed highest TS expression (mean TS/β-actin, 13.8) and that squamous cell carcinoma showed higher TS expression as compared with adenocarcinoma (mean TS/β-actin, 4.3 and 2.3, respectively; P < 0.01); TS gene expression was significantly increased along with a decrease in the grade of tumor cell differentiation. There was no significant difference in TS gene expression according to any other patient characteristics including tumor progression. Lower TS expression in adenocarcinoma of the lung was confirmed in a large-scale study.

  15. The control and importance of hyaluronan synthase expression in palatogenesis

    PubMed Central

    Galloway, Jennifer L.; Jones, Sarah J.; Mossey, Peter A.; Ellis, Ian R.

    2013-01-01

    Development of the lip and palate involves a complex series of events that requires the close co-ordination of cell migration, growth, differentiation, and apoptosis. Palatal shelf elevation is considered to be driven by regional accumulation and hydration of glycosoaminoglycans, principally hyaluronan (HA), which provides an intrinsic shelf force, directed by components of the extracellular matrix (ECM). During embryogenesis, the extracellular and pericellular matrix surrounding migrating and proliferating cells is rich in HA. This would suggest that HA may be important in both shelf growth and fusion. TGFβ3 plays an important role in palatogenesis and the corresponding homozygous null (TGFβ3−/−) mouse, exhibits a defect in the fusion of the palatal shelves resulting in clefting of the secondary palate. TGFβ3 is expressed at the future medial edge epithelium (MEE) and at the actual edge epithelium during E14.5, suggesting a role for TGFβ3 in fusion. This is substantiated by experiments showing that addition of exogenous TGFβ3 can “rescue” the cleft palate phenotype in the null mouse. In addition, TGFβ1 and TGFβ2 can rescue the null mouse palate (in vitro) to near normal fusion. In vivo a TGFβ1 knock-in mouse, where the coding region of the TGFβ3 gene was replaced with the full-length TGFβ1 cDNA, displayed complete fusion at the mid portion of the secondary palate, whereas the anterior and posterior regions failed to fuse appropriately. We present experimental data indicating that the three HA synthase (Has) enzymes are differentially expressed during palatogenesis. Using immunohistochemistry (IHC) and embryo sections from the TGFβ3 null mouse at days E13.5 and E14.5, it was established that there was a decrease in expression of Has2 in the mesenchyme and an increase in expression of Has3 in comparison to the wild-type mouse. In vitro data indicate that HA synthesis is affected by addition of exogenous TGFβ3. Preliminary data suggests that this

  16. Alcoholytic Cleavage of Polyhydroxyalkanoate Chains by Class IV Synthases Induced by Endogenous and Exogenous Ethanol

    PubMed Central

    Hyakutake, Manami; Tomizawa, Satoshi; Mizuno, Kouhei; Abe, Hideki

    2014-01-01

    Polyhydroxyalkanoate (PHA)-producing Bacillus strains express class IV PHA synthase, which is composed of the subunits PhaR and PhaC. Recombinant Escherichia coli expressing PHA synthase from Bacillus cereus strain YB-4 (PhaRCYB-4) showed an unusual reduction of the molecular weight of PHA produced during the stationary phase of growth. Nuclear magnetic resonance analysis of the low-molecular-weight PHA revealed that its carboxy end structure was capped by ethanol, suggesting that the molecular weight reduction was the result of alcoholytic cleavage of PHA chains by PhaRCYB-4 induced by endogenous ethanol. This scission reaction was also induced by exogenous ethanol in both in vivo and in vitro assays. In addition, PhaRCYB-4 was observed to have alcoholysis activity for PHA chains synthesized by other synthases. The PHA synthase from Bacillus megaterium (PhaRCBm) from another subgroup of class IV synthases was also assayed and was shown to have weak alcoholysis activity for PHA chains. These results suggest that class IV synthases may commonly share alcoholysis activity as an inherent feature. PMID:24334666

  17. Testis-specific ATP synthase peripheral stalk subunits required for tissue-specific mitochondrial morphogenesis in Drosophila.

    PubMed

    Sawyer, Eric M; Brunner, Elizabeth C; Hwang, Yihharn; Ivey, Lauren E; Brown, Olivia; Bannon, Megan; Akrobetu, Dennis; Sheaffer, Kelsey E; Morgan, Oshauna; Field, Conroy O; Suresh, Nishita; Gordon, M Grace; Gunnell, E Taylor; Regruto, Lindsay A; Wood, Cricket G; Fuller, Margaret T; Hales, Karen G

    2017-03-23

    In Drosophila early post-meiotic spermatids, mitochondria undergo dramatic shaping into the Nebenkern, a spherical body with complex internal structure that contains two interwrapped giant mitochondrial derivatives. The purpose of this study was to elucidate genetic and molecular mechanisms underlying the shaping of this structure. The knotted onions (knon) gene encodes an unconventionally large testis-specific paralog of ATP synthase subunit d and is required for internal structure of the Nebenkern as well as its subsequent disassembly and elongation. Knon localizes to spermatid mitochondria and, when exogenously expressed in flight muscle, alters the ratio of ATP synthase complex dimers to monomers. By RNAi knockdown we uncovered mitochondrial shaping roles for other testis-expressed ATP synthase subunits. We demonstrate the first known instance of a tissue-specific ATP synthase subunit affecting tissue-specific mitochondrial morphogenesis. Since ATP synthase dimerization is known to affect the degree of inner mitochondrial membrane curvature in other systems, the effect of Knon and other testis-specific paralogs of ATP synthase subunits may be to mediate differential membrane curvature within the Nebenkern.

  18. Aldosterone Target NGAL (Neutrophil Gelatinase-Associated Lipocalin) Is Involved in Cardiac Remodeling After Myocardial Infarction Through NFκB Pathway.

    PubMed

    Martínez-Martínez, Ernesto; Buonafine, Mathieu; Boukhalfa, Ines; Ibarrola, Jaime; Fernández-Celis, Amaya; Kolkhof, Peter; Rossignol, Patrick; Girerd, Nicolas; Mulder, Paul; López-Andrés, Natalia; Ouvrard-Pascaud, Antoine; Jaisser, Frédéric

    2017-12-01

    Myocardial infarction (MI) is accompanied by cardiac fibrosis, which contributes to cardiac dysfunction. Mineralocorticoid receptor (MR) antagonists have beneficial effects in patients with left ventricular (LV) dysfunction after MI. We herein investigated the role of the MR target NGAL (neutrophil gelatinase-associated lipocalin) in post-MI cardiac damages. Both higher baseline NGAL and a greater increase in serum NGAL levels during follow-up were significantly associated with lower 6-month LV ejection fraction recovery in a cohort of 119 post-MI patients, as assessed by cardiac magnetic resonance imaging. NGAL protein levels increased in the LV at 7 days post-MI in wild-type mice with MI. This effect was prevented by treatment with the nonsteroidal MR antagonist finerenone (1 mg/kg per day). NGAL knockout mice with MI had lower LV interstitial fibrosis and inflammation, better LV contractility and compliance, and greater stroke volume and cardiac output than wild-type mice with MI at 3 months post-MI. Aldosterone (10 -8 mol/L) increased NGAL expression in cultured human cardiac fibroblasts. Cells treated with aldosterone or NGAL (500 ng/mL) showed increased production of collagen type I. The effects of aldosterone were abolished by finerenone (10 -6 mol/L) or NGAL knockdown. This NGAL-mediated activity relied on NFκB (nuclear factor-κB) activation, confirmed by the use of the NFκB-specific inhibitor BAY11-7082, which prevented the effect of both aldosterone and NGAL on collagen type I production. In conclusion, NGAL, a downstream MR activation target, is a key mediator of post-MI cardiac damage. NGAL may be a potential therapeutic target in cardiovascular pathological situations in which MR is involved. © 2017 American Heart Association, Inc.

  19. Genetic construction and functional analysis of hybrid polyketide synthases containing heterologous acyl carrier proteins.

    PubMed Central

    Khosla, C; McDaniel, R; Ebert-Khosla, S; Torres, R; Sherman, D H; Bibb, M J; Hopwood, D A

    1993-01-01

    The gene that encodes the acyl carrier protein (ACP) of the actinorhodin polyketide synthase (PKS) of Streptomyces coelicolor A3(2) was replaced with homologs from the granaticin, oxytetracycline, tetracenomycin, and putative frenolicin polyketide synthase gene clusters. All of the replacements led to expression of functional synthases, and the recombinants synthesized aromatic polyketides similar in chromatographic properties to actinorhodin or to shunt products produced by mutants defective in the actinorhodin pathway. Some regions within the ACP were also shown to be interchangeable and allow production of a functional hybrid ACP. Structural analysis of the most abundant polyketide product of one of the recombinants by electrospray mass spectrometry suggested that it is identical to mutactin, a previously characterized shunt product of an actVII mutant (deficient in cyclase and dehydrase activities). Quantitative differences in the product profiles of strains that express the various hybrid synthases were observed. These can be explained, at least in part, by differences in ribosome-binding sites upstream of each ACP gene, implying either that the ACP concentration in some strains is rate limiting to overall PKS activity or that the level of ACP expression also influences the expression of another enzyme(s) encoded by a downstream gene(s) in the same operon as the actinorhodin ACP gene. These results reaffirm the idea that construction of hybrid polyketide synthases will be a useful approach for dissecting the molecular basis of the specificity of PKS-catalyzed reactions. However, they also point to the need for reducing the chemical complexity of the approach by minimizing the diversity of polyketide products synthesized in strains that produce recombinant polyketide synthases. Images PMID:8468280

  20. Myocardial pathology induced by aldosterone is dependent on non-canonical activities of G protein-coupled receptor kinases

    PubMed Central

    Cannavo, Alessandro; Liccardo, Daniela; Eguchi, Akito; Elliott, Katherine J.; Traynham, Christopher J.; Ibetti, Jessica; Eguchi, Satoru; Leosco, Dario; Ferrara, Nicola; Rengo, Giuseppe; Koch, Walter J.

    2016-01-01

    Hyper-aldosteronism is associated with myocardial dysfunction including induction of cardiac fibrosis and maladaptive hypertrophy. Mechanisms of these cardiotoxicities are not fully understood. Here we show that mineralocorticoid receptor (MR) activation by aldosterone leads to pathological myocardial signalling mediated by mitochondrial G protein-coupled receptor kinase 2 (GRK2) pro-death activity and GRK5 pro-hypertrophic action. Moreover, these MR-dependent GRK2 and GRK5 non-canonical activities appear to involve cross-talk with the angiotensin II type-1 receptor (AT1R). Most importantly, we show that ventricular dysfunction caused by chronic hyper-aldosteronism in vivo is completely prevented in cardiac Grk2 knockout mice (KO) and to a lesser extent in Grk5 KO mice. However, aldosterone-induced cardiac hypertrophy is totally prevented in Grk5 KO mice. We also show human data consistent with MR activation status in heart failure influencing GRK2 levels. Therefore, our study uncovers GRKs as targets for ameliorating pathological cardiac effects associated with high-aldosterone levels. PMID:26932512

  1. Class IV polyhydroxyalkanoate (PHA) synthases and PHA-producing Bacillus.

    PubMed

    Tsuge, Takeharu; Hyakutake, Manami; Mizuno, Kouhei

    2015-08-01

    This review highlights the recent investigations of class IV polyhydroxyalkanoate (PHA) synthases, the newest classification of PHA synthases. Class IV synthases are prevalent in organisms of the Bacillus genus and are composed of a catalytic subunit PhaC (approximately 40 kDa), which has a PhaC box sequence ([GS]-X-C-X-[GA]-G) at the active site, and a second subunit PhaR (approximately 20 kDa). The representative PHA-producing Bacillus strains are Bacillus megaterium and Bacillus cereus; the nucleotide sequence of phaC and the genetic organization of the PHA biosynthesis gene locus are somewhat different between these two strains. It is generally considered that class IV synthases favor short-chain-length monomers such as 3-hydroxybutyrate (C4) and 3-hydroxyvalerate (C5) for polymerization, but can polymerize some unusual monomers as minor components. In Escherichia coli expressing PhaRC from B. cereus YB-4, the biosynthesized PHA undergoes synthase-catalyzed alcoholytic cleavage using endogenous and exogenous alcohols. This alcoholysis is thought to be shared among class IV synthases, and this reaction is useful not only for the regulation of PHA molecular weight but also for the modification of the PHA carboxy terminus. The novel properties of class IV synthases will open up the possibility for the design of new PHA materials.

  2. Effect of aldosterone breakthrough on albuminuria during treatment with a direct renin inhibitor and combined effect with a mineralocorticoid receptor antagonist.

    PubMed

    Sato, Atsuhisa; Fukuda, Seiichi

    2013-10-01

    We have reported observing aldosterone breakthrough in the course of relatively long-term treatment with renin-angiotensin (RA) system inhibitors, where the plasma aldosterone concentration (PAC) increased following an initial decrease. Aldosterone breakthrough has the potential to eliminate the organ-protective effects of RA system inhibitors. We therefore conducted a study in essential hypertensive patients to determine whether aldosterone breakthrough occurred during treatment with the direct renin inhibitor (DRI) aliskiren and to ascertain its clinical significance. The study included 40 essential hypertensive patients (18 men and 22 women) who had been treated for 12 months with aliskiren. Aliskiren significantly decreased blood pressure and plasma renin activity (PRA). The PAC was also decreased significantly at 3 and 6 months; however, the significant difference disappeared after 12 months. Aldosterone breakthrough was observed in 22 of the subjects (55%). Urinary albumin excretion differed depending on whether breakthrough occurred. For the subjects in whom aldosterone breakthrough was observed, eplerenone was added. A significant decrease in urinary albumin excretion was observed after 1 month, independent of changes in blood pressure. In conclusion, this study demonstrated that aldosterone breakthrough occurs in some patients undergoing DRI therapy. Aldosterone breakthrough affects the drug's ability to improve urinary albumin excretion, and combining a mineralocorticoid receptor antagonist with the DRI may be useful for decreasing urinary albumin excretion. When the objective is organ protection in hypertensive patients, a two-pronged approach using combination therapy to inhibit both the RA system and aldosterone may be highly effective.

  3. Race, obesity, and the renin-angiotensin-aldosterone system: treatment response in children with primary hypertension.

    PubMed

    South, Andrew M; Arguelles, Lester; Finer, Gal; Langman, Craig B

    2017-09-01

    Pediatric primary hypertension (HTN) is increasingly recognized, but the effect of patient characteristics such as obesity and race on treatment outcomes is not well described. The renin-angiotensin-aldosterone system (RAAS) may also contribute to HTN. We hypothesized patient parameters of these factors, including baseline RAAS, influence blood pressure (BP) response to pharmacological treatment in HTN. This was a retrospective cohort of 102 consecutive patients with HTN. Primary outcomes were changes per year in systolic and diastolic BP (SBP, DBP). Secondary outcome was change per year in left ventricular mass index (LVMI). We evaluated whether baseline plasma renin activity (PRA), aldosterone, renin-to-aldosterone ratio, overweight/obesity, race, initial drug choice, and multidrug therapy were associated with the outcomes using general linear regression models adjusted for confounding variables. Racially diverse (43% Hispanic, 28% black, 25% white) and predominantly overweight/obese (75%) patients were studied. Median length of follow-up was 14.5 months. Higher baseline aldosterone was associated with decreased SBP (-1.03 mmHg/year), DBP (-0.95 mmHg/year), and DBP z score (-0.07/year) during the study period. Higher baseline PRA was associated with decreased SBP z score (-0.04/year) and LVMI (-2.89 g/m 2.7 /year). Stratified analyses revealed the relationships between baseline aldosterone and PRA, and annual reductions in outcomes were strengthened in nonobese and white patients. Pretreatment aldosterone and PRA predicted short-term follow-up BP and LVMI, especially in nonobese and white patients. The RAAS profile could guide treatment of HTN and suggests consideration of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers as first-line treatment options.

  4. Hormonal therapy deregulates prostaglandin-endoperoxidase synthase 2 (PTGS2) expression in endometriotic tissues.

    PubMed

    Santulli, Pietro; Borghese, Bruno; Noël, Jean-Christophe; Fayt, Isabelle; Anaf, Vincent; de Ziegler, Dominique; Batteux, Frederic; Vaiman, Daniel; Chapron, Charles

    2014-03-01

    Endometriosis is a common gynecologic condition characterized by an important inflammatory process mediated by the prostaglandin pathway. Oral contraceptives are the treatment of choice for symptomatic endometriotic women. However the effects of oral contraceptives use and prostaglandin pathway in endometriotic women are actually still unknown. To investigate the expression of prostaglandin pathway key genes in endometriotic tissue, affected or not by hormonal therapy, as compared with healthy endometrial tissue. This was a comparative laboratory study. This study was conducted in a tertiary-care university hospital. Seventy-six women, with (n = 46) and without (n = 30) histologically proven endometriosis. Prostaglandin-endoperoxidase synthase (PTGS)1, PTGS2, prostaglandin E receptor (PTGER)1, PTGER2, PTGER3, and PTGER4 mRNA levels in endometrium of disease-free women and in eutopic and ectopic endometrium of endometriosis-affected women. PTGS2 expression was further investigated by immunohistochemistry, using specific monoclonal antibodies. PTGS2 expression was analyzed at mRNA and protein levels and correlated with taking hormonal treatment. PTGS2 expression was significantly increased in eutopic and ectopic endometrium as compared with healthy tissue (induction of 9.6- and 6.3-fold, respectively; P = .001). PTGS2 immunoreactivity increased gradually from normal endometrium to eutopic and ectopic endometrium (h-score of 96.7 ± 55.0, 128.3 ± 66.1, and 226.7 ± 62.6, respectively, P < .001). PTGER2, PTGER3, and PTGER4 expression increased significantly and gradually from normal to eutopic and ectopic endometrium, whereas PTGER1 remained unchanged. Patients under hormonal treatment had a higher PTGS2 expression at transcriptional and protein levels as compared with those without treatment (P = .002 and P = .025, respectively). Prostaglandin pathway is strongly deregulated in eutopic and ectopic endometrium of women suffering from endometriosis for the benefit of

  5. Eplerenone: a selective aldosterone receptor antagonist for patients with heart failure.

    PubMed

    Barnes, Brian J; Howard, Patricia A

    2005-01-01

    To evaluate the pharmacology, pharmacokinetics, safety, and clinical use of eplerenone in heart failure (HF). English-language MEDLINE searches were performed from 1966 to May 2004. Key words included eplerenone, aldosterone receptor antagonist, heart failure, myocardial infarction, left-ventricular dysfunction, and cost-effectiveness. Additional references were identified from bibliographies of selected articles. Human trials evaluating the efficacy, safety, and cost-effectiveness of aldosterone receptor antagonists in HF were evaluated. Eplerenone is the first selective aldosterone receptor antagonist. The drug is indicated to improve the survival of stable patients with left-ventricular systolic dysfunction (ejection fraction <40%) and clinical evidence of HF following acute myocardial infarction. Efficacy and safety in this population have been demonstrated in a large, randomized clinical trial. Eplerenone is associated with severe and sometimes life-threatening hyperkalemia. Patients with reduced renal function and diabetes, as well as those on other drugs that increase potassium levels, are at highest risk. Eplerenone is metabolized by the cytochrome P450 system and may interact with drugs that interfere with this system. A major advantage of eplerenone over the nonselective aldosterone receptor antagonist spironolactone is lack of binding to progesterone and androgen receptors, which is associated with drug-induced gynecomastia, breast pain, and impotence. The addition of eplerenone to traditional HF therapy has been shown to reduce morbidity and mortality in patients who develop left-ventricular dysfunction after acute myocardial infarction. Eplerenone's selectivity reduces sex hormone-related adverse effects. Despite these benefits, the overall cost-effectiveness has yet to be determined.

  6. Functional Identification of Valerena-1,10-diene Synthase, a Terpene Synthase Catalyzing a Unique Chemical Cascade in the Biosynthesis of Biologically Active Sesquiterpenes in Valeriana officinalis*

    PubMed Central

    Yeo, Yun-Soo; Nybo, S. Eric; Chittiboyina, Amar G.; Weerasooriya, Aruna D.; Wang, Yan-Hong; Góngora-Castillo, Elsa; Vaillancourt, Brieanne; Buell, C. Robin; DellaPenna, Dean; Celiz, Mary Dawn; Jones, A. Daniel; Wurtele, Eve Syrkin; Ransom, Nick; Dudareva, Natalia; Shaaban, Khaled A.; Tibrewal, Nidhi; Chandra, Suman; Smillie, Troy; Khan, Ikhlas A.; Coates, Robert M.; Watt, David S.; Chappell, Joe

    2013-01-01

    Valerian is an herbal preparation from the roots of Valeriana officinalis used as an anxiolytic and sedative and in the treatment of insomnia. The biological activities of valerian are attributed to valerenic acid and its putative biosynthetic precursor valerenadiene, sesquiterpenes, found in V. officinalis roots. These sesquiterpenes retain an isobutenyl side chain whose origin has been long recognized as enigmatic because a chemical rationalization for their biosynthesis has not been obvious. Using recently developed metabolomic and transcriptomic resources, we identified seven V. officinalis terpene synthase genes (VoTPSs), two that were functionally characterized as monoterpene synthases and three that preferred farnesyl diphosphate, the substrate for sesquiterpene synthases. The reaction products for two of the sesquiterpene synthases exhibiting root-specific expression were characterized by a combination of GC-MS and NMR in comparison to the terpenes accumulating in planta. VoTPS7 encodes for a synthase that biosynthesizes predominately germacrene C, whereas VoTPS1 catalyzes the conversion of farnesyl diphosphate to valerena-1,10-diene. Using a yeast expression system, specific labeled [13C]acetate, and NMR, we investigated the catalytic mechanism for VoTPS1 and provide evidence for the involvement of a caryophyllenyl carbocation, a cyclobutyl intermediate, in the biosynthesis of valerena-1,10-diene. We suggest a similar mechanism for the biosynthesis of several other biologically related isobutenyl-containing sesquiterpenes. PMID:23243312

  7. Functional identification of valerena-1,10-diene synthase, a terpene synthase catalyzing a unique chemical cascade in the biosynthesis of biologically active sesquiterpenes in Valeriana officinalis.

    PubMed

    Yeo, Yun-Soo; Nybo, S Eric; Chittiboyina, Amar G; Weerasooriya, Aruna D; Wang, Yan-Hong; Góngora-Castillo, Elsa; Vaillancourt, Brieanne; Buell, C Robin; DellaPenna, Dean; Celiz, Mary Dawn; Jones, A Daniel; Wurtele, Eve Syrkin; Ransom, Nick; Dudareva, Natalia; Shaaban, Khaled A; Tibrewal, Nidhi; Chandra, Suman; Smillie, Troy; Khan, Ikhlas A; Coates, Robert M; Watt, David S; Chappell, Joe

    2013-02-01

    Valerian is an herbal preparation from the roots of Valeriana officinalis used as an anxiolytic and sedative and in the treatment of insomnia. The biological activities of valerian are attributed to valerenic acid and its putative biosynthetic precursor valerenadiene, sesquiterpenes, found in V. officinalis roots. These sesquiterpenes retain an isobutenyl side chain whose origin has been long recognized as enigmatic because a chemical rationalization for their biosynthesis has not been obvious. Using recently developed metabolomic and transcriptomic resources, we identified seven V. officinalis terpene synthase genes (VoTPSs), two that were functionally characterized as monoterpene synthases and three that preferred farnesyl diphosphate, the substrate for sesquiterpene synthases. The reaction products for two of the sesquiterpene synthases exhibiting root-specific expression were characterized by a combination of GC-MS and NMR in comparison to the terpenes accumulating in planta. VoTPS7 encodes for a synthase that biosynthesizes predominately germacrene C, whereas VoTPS1 catalyzes the conversion of farnesyl diphosphate to valerena-1,10-diene. Using a yeast expression system, specific labeled [(13)C]acetate, and NMR, we investigated the catalytic mechanism for VoTPS1 and provide evidence for the involvement of a caryophyllenyl carbocation, a cyclobutyl intermediate, in the biosynthesis of valerena-1,10-diene. We suggest a similar mechanism for the biosynthesis of several other biologically related isobutenyl-containing sesquiterpenes.

  8. Plasma potassium concentrations in neonatal diarrhoeic calves are correlated with serum aldosterone concentrations but not with insulin concentrations.

    PubMed

    Trefz, Florian M; Lorenz, Ingrid

    2017-12-01

    Hyperkalaemia is a clinically relevant electrolyte imbalance in neonatal diarrhoeic calves which was previously associated with severe dehydration and acidaemia. The present study assessed the association of plasma potassium (cK) with serum aldosterone and insulin concentrations, since these hormones are involved in the regulation of potassium homeostasis. Serum aldosterone (r s =0.62), but not insulin concentrations (r s =0.22) were closely correlated to cK in 123 hospitalised neonatal diarrhoeic calves. Median values for serum aldosterone concentrations in 38 hyperkalaemic calves (cK>5.8mmol/L) were 3.2 and 15.3 times higher (P<0.001) than in 85 non-hyperkalaemic diarrhoeic calves and nine healthy control calves, respectively. Aldosterone, but not insulin secretion, appears to be highly stimulated in dehydrated diarrhoeic calves with hyperkalaemia, but hypovolaemia and a concomitant decrease in renal perfusion and urinary flow rate are likely to limit the efficacy of aldosterone-induced control mechanisms in these animals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Actions of circulating angiotensin II and aldosterone in the brain contributing to hypertension.

    PubMed

    Leenen, Frans H H

    2014-08-01

    In the past 1-2 decades, it has become apparent that the brain renin-angiotensin-aldosterone system (RAAS) plays a crucial role in the regulation of blood pressure (BP) by the circulating RAAS. In the brain, angiotensinergic sympatho-excitatory pathways do not contribute to acute, second-to-second regulation but play a major role in the more chronic regulation of the setpoint for sympathetic tone and BP. Increases in plasma angiotensin II (Ang II) or aldosterone and in cerebrospinal fluid [Na(+)] can directly activate these pathways and chronically further activate/maintain enhanced activity by a slow neuromodulatory pathway involving local aldosterone, mineralocorticoid receptors (MRs), epithelial sodium channels, and endogenous ouabain. Blockade of any step in this slow pathway prevents Ang II-, aldosterone-, or salt and renal injury-induced forms of hypertension. It appears that the renal and arterial actions of circulating aldosterone and Ang II act as amplifiers but are not sufficient to cause chronic hypertension if their central actions are prevented, except perhaps at high concentrations. From a clinical perspective, oral treatment with an angiotensin type 1 (AT1)-receptor blocker at high doses can cause central AT1-receptor blockade and, in humans, lower sympathetic nerve activity. Low doses of the MR blocker spironolactone appear sufficient to cause central MR blockade and a decrease in sympathetic nerve activity. Integrating the brain actions of the circulating RAAS with its direct renal and arterial actions provides a better framework to understand the role of the circulating RAAS in the pathophysiology of hypertension and heart failure and to direct therapeutic strategies. © American Journal of Hypertension, Ltd 2014. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Aldosterone stimulates vacuolar H+-ATPase activity in renal acid-secretory intercalated cells mainly via a protein kinase C-dependent pathway

    PubMed Central

    Winter, Christian; Kampik, Nicole B.; Vedovelli, Luca; Rothenberger, Florina; Păunescu, Teodor G.; Stehberger, Paul A.; Brown, Dennis; John, Hubert

    2011-01-01

    Urinary acidification in the collecting duct is mediated by the activity of H+-ATPases and is stimulated by various factors including angiotensin II and aldosterone. Classically, aldosterone effects are mediated via the mineralocorticoid receptor. Recently, we demonstrated a nongenomic stimulatory effect of aldosterone on H+-ATPase activity in acid-secretory intercalated cells of isolated mouse outer medullary collecting ducts (OMCD). Here we investigated the intracellular signaling cascade mediating this stimulatory effect. Aldosterone stimulated H+-ATPase activity in isolated mouse and human OMCDs. This effect was blocked by suramin, a general G protein inhibitor, and GP-2A, a specific Gαq inhibitor, whereas pertussis toxin was without effect. Inhibition of phospholipase C with U-73122, chelation of intracellular Ca2+ with BAPTA, and blockade of protein kinase C prevented the stimulation of H+-ATPases. Stimulation of PKC by DOG mimicked the effect of aldosterone on H+-ATPase activity. Similarly, aldosterone and DOG induced a rapid translocation of H+-ATPases to the luminal side of OMCD cells in vivo. In addition, PD098059, an inhibitor of ERK1/2 activation, blocked the aldosterone and DOG effects. Inhibition of PKA with H89 or KT2750 prevented and incubation with 8-bromoadenosine-cAMP mildly increased H+-ATPase activity. Thus, the nongenomic modulation of H+-ATPase activity in OMCD-intercalated cells by aldosterone involves several intracellular pathways and may be mediated by a Gαq protein-coupled receptor and PKC. PKA and cAMP appear to have a modulatory effect. The rapid nongenomic action of aldosterone may participate in the regulation of H+-ATPase activity and contribute to final urinary acidification. PMID:21832245

  11. [Effects of cytosolic bacteria on cyclic GMP-AMP synthase expression in human gingival tissues and periodontal ligament cells].

    PubMed

    Xiaojun, Yang; Yongmei, Tan; Zhihui, Tian; Ting, Zhou; Wanghong, Zhao; Jin, Hou

    2017-04-01

    This work aims to determine the effect of cytosolic bacteria on the expression of cyclic GMP-AMP synthase (cGAS) in human periodontal ligament cells (hPDLCs) and gingival tissues. The ability of Porphyromonas gingivalis (P. gingivalis) to invade hPDLCs was detected using laser scanning confocal microscope assay at a multiplicity of infection of 10. P. gingivalis-infected cells were sorted by fluorescence-activated cell sorting (FACS). Then, quantitative real time reverse transcription polymerase chain reaction (qRT-PCR) and Western blot were used to detect cGAS expression in infected cells. Finally, the location and expression of cGAS in inflammatory and normal gingival tissues were investigated by immunohistochemistry. P. gingivalis actively invaded hPDLCs. Moreover, cGAS expression significantly increased in P. gingivalis-infected cells. Although cGAS was expressed in the epithelial and subepithelial cells of both inflamed and normal gingival tissues, cGAS expression significantly increased in inflamed gingival tissues. Cytosolic bacteria can upregulate cGAS expression in infected cells. These data suggest that cGAS may act as pattern-recognition receptors and participate in recognizing cytosolic nucleic acid pathogen-associated molecular patterns.
.

  12. Interrelated aldosterone and parathyroid hormone mutually modify cardiovascular mortality risk.

    PubMed

    Tomaschitz, Andreas; Pilz, Stefan; Rus-Machan, Jutta; Meinitzer, Andreas; Brandenburg, Vincent M; Scharnagl, Hubert; Kapl, Martin; Grammer, Tanja; Ritz, Eberhard; Horina, Jörg H; Kleber, Marcus E; Pieske, Burkert; Kraigher-Krainer, Elisabeth; Hartaigh, Bríain Ó; Toplak, Hermann; van Ballegooijen, Adriana J; Amrein, Karin; Fahrleitner-Pammer, Astrid; März, Winfried

    2015-04-01

    Inappropriate aldosterone and parathyroid hormone (PTH) secretion is associated with increased cardiovascular risk. Accumulating evidence suggests bidirectional interplay between aldosterone and PTH. We evaluated the cross-sectional relationship between plasma aldosterone concentration (PAC), aldosterone to renin ratio (ARR) and PTH and subsequently tested whether the interaction between PAC and PTH modified the risk of cardiovascular death. PAC [78.0 (48.0-123.0) pg/mL], ARR [6.4 (2.9-12.9) pg/mL/pg/mL] and PTH concentration [median: 29.0 (22.0-40.0) pg/mL] were measured in 3074 patients (mean age: 62.5 ± 10.6 years; 30.3% women) referred to coronary angiography in a tertiary care center in Southwest Germany. Using multiple linear regression analysis, PAC and ARR emerged as an independent predictor of higher PTH concentrations (β=0.12 and 0.21, P<0.001 for both) irrespective of intake of antihypertensive treatment, 25(OH)D, kidney function, serum calcium, phosphate, magnesium, cortisol, NT-pro-BNP, soluble α-klotho and FGF-23 concentration. After a median follow-up of 9.9 years, 512 (16.7%) participants had died due to fatal cardiovascular events. Multivariate Cox proportional hazard analysis revealed that both PAC and PTH were independently associated with cardiovascular mortality, with a potential synergistic interaction (P=0.028). PAC and PTH are exclusively associated with cardiovascular death in subjects with PTH and PAC concentrations above the median, respectively (PAC: HR per log SD: 1.14; 95% CI 1.02-1.29; P=0.026; PTH: HR per log SD: 1.18; 95% CI 1.02-1.37; P=0.031). Higher PAC and ARR were independently associated with PTH. PAC was independently related to incident cardiovascular mortality exclusively in patients with elevated PTH and vice versa. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. Persistent Primary Aldosteronism Despite Iatrogenic Adrenal Hemorrhage After Adrenal Vein Sampling.

    PubMed

    Okamura, Keisuke; Okuda, Tetsu; Shirai, Kazuyuki; Abe, Ichiro; Kobayashi, Kunihisa; Ishii, Tatsu; Haraoka, Seiji; Urata, Hidenori

    2018-01-01

    Before surgery for primary aldosteronism (PA), localization is evaluated with adrenal vein sampling (AVS). A 56-year-old Japanese woman had a right adrenal mass, hypokalemia, and a high aldosterone/renin ratio. Stress tests confirmed the diagnosis of PA. Subsequently, preoperative AVS was performed and right adrenal hemorrhage (AH) occurred unexpectedly. Because hypertension persisted, laparoscopic right adrenalectomy was performed. Postoperatively, the blood pressure was normalized. Pathological examination revealed an adrenal cortical adenoma largely unaffected by necrosis and hemorrhage. Previous reports have also indicated that AH may not ameliorate PA. We discussed the clinical progress of AH and the measures to prevent causing AH.

  14. Primary aldosteronism among newly diagnosed and untreated hypertensive patients in a Swedish primary care area.

    PubMed

    Westerdahl, Christina; Bergenfelz, Anders; Isaksson, Anders; Nerbrand, Christina; Valdemarsson, Stig

    2011-03-01

    To evaluate the prevalence of primary aldosteronism (PA) in newly diagnosed and untreated hypertensive patients in primary care using the aldosterone/renin ratio (ARR), and to assess clinical and biochemical characteristics in patients with high and normal ARR. Patient survey study. A total of 200 consecutive patients with newly diagnosed and untreated hypertension from six primary health care centres in Sweden were included. ARR was calculated from serum aldosterone and plasma renin concentrations. The cut-off level for ARR was 65. Patients with an increased ARR were considered for confirmatory testing with the fludrocortisone suppression test (FST), followed by adrenal computed tomographic radiology (CT) and adrenal venous sampling (AVS). Of 200 patients, 36 patients had an ARR > 65. Of these 36 patients, 11 patients had an incomplete aldosterone inhibition during FST. Three patients were diagnosed with an aldosterone producing adenoma (APA) and eight with bilateral adrenal hyperplasia (BHA). Except for moderately lower level of P-K in patients with an ARR > 65 and in patients with PA, there were no biochemical or clinical differences found among hypertensive patients with PA compared with patients without PA. Eleven of 200 evaluated patients (5.5%) were considered to have PA. The diagnosis of PA should therefore be considered in newly diagnosed hypertensive subjects and screening for the diagnosis is warranted.

  15. Primary aldosteronism among newly diagnosed and untreated hypertensive patients in a Swedish primary care area

    PubMed Central

    Westerdahl, Christina; Bergenfelz, Anders; Isaksson, Anders; Nerbrand, Christina; Valdemarsson, Stig

    2011-01-01

    Objective To evaluate the prevalence of primary aldosteronism (PA) in newly diagnosed and untreated hypertensive patients in primary care using the aldosterone/renin ratio (ARR), and to assess clinical and biochemical characteristics in patients with high and normal ARR. Design Patient survey study. Setting and subjects A total of 200 consecutive patients with newly diagnosed and untreated hypertension from six primary health care centres in Sweden were included. Main outcome measures ARR was calculated from serum aldosterone and plasma renin concentrations. The cut-off level for ARR was 65. Patients with an increased ARR were considered for confirmatory testing with the fludrocortisone suppression test (FST), followed by adrenal computed tomographic radiology (CT) and adrenal venous sampling (AVS). Results Of 200 patients, 36 patients had an ARR > 65. Of these 36 patients, 11 patients had an incomplete aldosterone inhibition during FST. Three patients were diagnosed with an aldosterone producing adenoma (APA) and eight with bilateral adrenal hyperplasia (BHA). Except for moderately lower level of P-K in patients with an ARR > 65 and in patients with PA, there were no biochemical or clinical differences found among hypertensive patients with PA compared with patients without PA. Conclusion Eleven of 200 evaluated patients (5.5%) were considered to have PA. The diagnosis of PA should therefore be considered in newly diagnosed hypertensive subjects and screening for the diagnosis is warranted. PMID:21323498

  16. Antihypertensive methyldopa, labetalol, hydralazine, and clonidine reversed tumour necrosis factor-α inhibited endothelial nitric oxide synthase expression in endothelial-trophoblast cellular networks.

    PubMed

    Xu, Bei; Bobek, Gabriele; Makris, Angela; Hennessy, Annemarie

    2017-03-01

    Medications used to control hypertension in pregnancy also improve trophoblast and endothelial cellular interaction in vitro. Tumour necrosis factor-α (TNF-α) inhibits trophoblast and endothelial cellular interactions and simultaneously decreases endothelial nitric oxide synthase (eNOS) expression. This study investigated whether antihypertensive medications improved these cellular interactions by modulating eNOS and inducible nitric oxide synthase (iNOS) expression. Human uterine myometrial microvascular endothelial cells (UtMVECs) were pre-incubated with (or without) low dose TNF-α (0.5 ng/mL) or TNF-α plus soluble fms-like tyrosine kinase-1 (sFlt-1) (100 ng/mL). The endothelial cells were cultured on Matrigel. After endothelial cellular networks appeared, trophoblast derived HTR-8/SVneo cells were co-cultured in the presence of clinically relevant doses of methyldopa, labetalol, hydralazine or clonidine for 24 hours. Cells were retrieved from the Matrigel to extract mRNA and eNOS and iNOS expression were examined by quantitative PCR. Methyldopa, labetalol, hydralazine and clonidine reversed the inhibitory effect of TNF-α on eNOS mRNA expression. After pre-incubating endothelial cells with TNF-α and sFlt-1, all the medications except methyldopa lost their effect on eNOS mRNA expression. In the absence of TNF-α, antihypertensive medications did not change eNOS expression. The mRNA expression of iNOS was not affected by TNF-α or any medications. This study shows that selected antihypertensive medications used in the treatment of hypertension in pregnancy increase eNOS expression in vitro when induced by the inflammatory TNF-α. The anti-angiogenic molecule sFlt-1 may antagonise the potential benefit of these medications by interfering with the NOS pathway. © 2016 John Wiley & Sons Australia, Ltd.

  17. Cardiac Hypertrophy and Fibrosis in the Metabolic Syndrome: A Role for Aldosterone and the Mineralocorticoid Receptor

    PubMed Central

    Essick, Eric E.; Sam, Flora

    2011-01-01

    Obesity and hypertension, major risk factors for the metabolic syndrome, render individuals susceptible to an increased risk of cardiovascular complications, such as adverse cardiac remodeling and heart failure. There has been much investigation into the role that an increase in the renin-angiotensin-aldosterone system (RAAS) plays in the pathogenesis of metabolic syndrome and in particular, how aldosterone mediates left ventricular hypertrophy and increased cardiac fibrosis via its interaction with the mineralocorticoid receptor (MR). Here, we review the pertinent findings that link obesity with elevated aldosterone and the development of cardiac hypertrophy and fibrosis associated with the metabolic syndrome. These studies illustrate a complex cross-talk between adipose tissue, the heart, and the adrenal cortex. Furthermore, we discuss findings from our laboratory that suggest that cardiac hypertrophy and fibrosis in the metabolic syndrome may involve cross-talk between aldosterone and adipokines (such as adiponectin). PMID:21747976

  18. In Planta Recapitulation of Isoprene Synthase Evolution from Ocimene Synthases

    PubMed Central

    Li, Mingai; Xu, Jia; Algarra Alarcon, Alberto; Carlin, Silvia; Barbaro, Enrico; Cappellin, Luca; Velikova, Violeta; Vrhovsek, Urska; Loreto, Francesco; Varotto, Claudio

    2017-01-01

    Abstract Isoprene is the most abundant biogenic volatile hydrocarbon compound naturally emitted by plants and plays a major role in atmospheric chemistry. It has been proposed that isoprene synthases (IspS) may readily evolve from other terpene synthases, but this hypothesis has not been experimentally investigated. We isolated and functionally validated in Arabidopsis the first isoprene synthase gene, AdoIspS, from a monocotyledonous species (Arundo donax L., Poaceae). Phylogenetic reconstruction indicates that AdoIspS and dicots isoprene synthases most likely originated by parallel evolution from TPS-b monoterpene synthases. Site-directed mutagenesis demonstrated invivo the functional and evolutionary relevance of the residues considered diagnostic for IspS function. One of these positions was identified by saturating mutagenesis as a major determinant of substrate specificity in AdoIspS able to cause invivo a dramatic change in total volatile emission from hemi- to monoterpenes and supporting evolution of isoprene synthases from ocimene synthases. The mechanism responsible for IspS neofunctionalization by active site size modulation by a single amino acid mutation demonstrated in this study might be general, as the very same amino acidic position is implicated in the parallel evolution of different short-chain terpene synthases from both angiosperms and gymnosperms. Based on these results, we present a model reconciling in a unified conceptual framework the apparently contrasting patterns previously observed for isoprene synthase evolution in plants. These results indicate that parallel evolution may be driven by relatively simple biophysical constraints, and illustrate the intimate molecular evolutionary links between the structural and functional bases of traits with global relevance. PMID:28637270

  19. Early nongenomic events in aldosterone action in renal collecting duct cells: PKCalpha activation, mineralocorticoid receptor phosphorylation, and cross-talk with the genomic response.

    PubMed

    Le Moëllic, Cathy; Ouvrard-Pascaud, Antoine; Capurro, Claudia; Cluzeaud, Francoise; Fay, Michel; Jaisser, Frederic; Farman, Nicolette; Blot-Chabaud, Marcel

    2004-05-01

    Effects of aldosterone on its target cells have long been considered to be mediated exclusively through the genomic pathway; however, evidence has been provided for rapid effects of the hormone that may involve nongenomic mechanisms. Whether an interaction exists between these two signaling pathways is not yet established. In this study, the authors show that aldosterone triggers both early nongenomic and late genomic increase in sodium transport in the RCCD(2) rat cortical collecting duct cell line. In these cells, the early (up to 2.5 h) aldosterone-induced increase in short-circuit current (Isc) is not blocked by the mineralocorticoid receptor (MR) antagonist RU26752, it does not require mRNA or protein synthesis, and it involves the PKCalpha signaling pathway. In addition, this early response is reproduced by aldosterone-BSA, which acts at the cell surface and presumably does not enter the cells (aldo-BSA is unable to trigger the late response). The authors also show that MR is rapidly phosphorylated on serine and threonine residues by aldosterone or aldosterone-BSA. In contrast, the late (4 to 24 h) aldosterone-induced increase in ion transport occurs through activation of the MR and requires mRNA and protein synthesis. Interestingly, nongenomic and genomic aldosterone actions appear to be interdependent. Blocking the PKCalpha pathway results in the inhibition of the late genomic response to aldosterone, as demonstrated by the suppression of aldosterone-induced increase in MR transactivation activity, alpha1 Na(+)/K(+)/ATPase mRNA, and Isc. These data suggest cross-talk between the nongenomic and genomic responses to aldosterone in renal cells and suggest that the aldosterone-MR mediated increase in mRNA/protein synthesis and ion transport depends, at least in part, upon PKCalpha activation. E-mail: marcel.blot-chabaud@pharmacie.univ-mrs.fr

  20. Feedback inhibition of nitric oxide synthase activity by nitric oxide.

    PubMed Central

    Assreuy, J.; Cunha, F. Q.; Liew, F. Y.; Moncada, S.

    1993-01-01

    1. A murine macrophage cell line, J774, expressed nitric oxide (NO) synthase activity in response to interferon-gamma (IFN-gamma, 10 u ml-1) plus lipopolysaccharide (LPS, 10 ng ml-1). The enzyme activity was first detectable 6 h after incubation, peaked at 12 h and became undetectable after 48 h. 2. The decline in the NO synthase activity was not due to inhibition by stable substances secreted by the cells into the culture supernatant. 3. The decline in the NO synthase activity was significantly slowed down in cells cultured in a low L-arginine medium or with added haemoglobin, suggesting that NO may be involved in a feedback inhibitory mechanism. 4. The addition of NO generators, S-nitroso-acetyl-penicillamine (SNAP) or S-nitroso-glutathione (GSNO) markedly inhibited the NO synthase activity in a dose-dependent manner. The effect of NO on the enzyme was not due to the inhibition of de novo protein synthesis. 5. SNAP directly inhibited the inducible NO synthase extracted from activated J774 cells, as well as the constitutive NO synthase extracted from the rat brain. 6. The enzyme activity of J774 cells was not restored after the removal of SNAP by gel filtration, suggesting that NO inhibits NO synthase irreversibly. PMID:7682140

  1. Renin and aldosterone measurements in the management of arterial hypertension.

    PubMed

    Viola, A; Monticone, S; Burrello, J; Buffolo, F; Lucchiari, M; Rabbia, F; Williams, T A; Veglio, F; Mengozzi, G; Mulatero, P

    2015-06-01

    Renin-angiotensin-aldosterone system (RAAS) is recognized as the main regulatory system of hemodynamics in man, and its derangements have a key role in the development and maintenance of arterial hypertension. Classification of the hypertensive states according to different patterns of renin and aldosterone levels ("RAAS profiling") allows the diagnosis of specific forms of secondary hypertension and may identify distinct hemodynamic subsets in essential hypertension. In this review, we summarize the application of RAAS profiling for the diagnostic assessment of hypertensive patients and discuss how the pathophysiological framework provided by RAAS profiling may guide therapeutic decision-making, especially in the context of uncontrolled hypertension not responding to multi-therapy. © Georg Thieme Verlag KG Stuttgart · New York.

  2. Riboflavin accumulation and characterization of cDNAs encoding lumazine synthase and riboflavin synthase in bitter melon (Momordica charantia).

    PubMed

    Tuan, Pham Anh; Kim, Jae Kwang; Lee, Sanghyun; Chae, Soo Cheon; Park, Sang Un

    2012-12-05

    Riboflavin (vitamin B2) is the universal precursor of the coenzymes flavin mononucleotide and flavin adenine dinucleotide--cofactors that are essential for the activity of a wide variety of metabolic enzymes in animals, plants, and microbes. Using the RACE PCR approach, cDNAs encoding lumazine synthase (McLS) and riboflavin synthase (McRS), which catalyze the last two steps in the riboflavin biosynthetic pathway, were cloned from bitter melon (Momordica charantia), a popular vegetable crop in Asia. Amino acid sequence alignments indicated that McLS and McRS share high sequence identity with other orthologous genes and carry an N-terminal extension, which is reported to be a plastid-targeting sequence. Organ expression analysis using quantitative real-time RT PCR showed that McLS and McRS were constitutively expressed in M. charantia, with the strongest expression levels observed during the last stage of fruit ripening (stage 6). This correlated with the highest level of riboflavin content, which was detected during ripening stage 6 by HPLC analysis. McLS and McRS were highly expressed in the young leaves and flowers, whereas roots exhibited the highest accumulation of riboflavin. The cloning and characterization of McLS and McRS from M. charantia may aid the metabolic engineering of vitamin B2 in crops.

  3. Adrenal vein sampling versus CT scan to determine treatment in primary aldosteronism: an outcome-based randomised diagnostic trial.

    PubMed

    Dekkers, Tanja; Prejbisz, Aleksander; Kool, Leo J Schultze; Groenewoud, Hans J M M; Velema, Marieke; Spiering, Wilko; Kołodziejczyk-Kruk, Sylwia; Arntz, Mark; Kądziela, Jacek; Langenhuijsen, Johannes F; Kerstens, Michiel N; van den Meiracker, Anton H; van den Born, Bert-Jan; Sweep, Fred C G J; Hermus, Ad R M M; Januszewicz, Andrzej; Ligthart-Naber, Alike F; Makai, Peter; van der Wilt, Gert-Jan; Lenders, Jacques W M; Deinum, Jaap

    2016-09-01

    The distinction between unilateral aldosterone-producing adenoma or bilateral adrenal hyperplasia as causes of primary aldosteronism is usually made by adrenal CT or by adrenal vein sampling (AVS). Whether CT or AVS represents the best test for diagnosis remains unknown. We aimed to compare the outcome of CT-based management with AVS-based management for patients with primary aldosteronism. In a randomised controlled trial, we randomly assigned patients with aldosteronism to undergo either adrenal CT or AVS to determine the presence of aldosterone-producing adenoma (with subsequent treatment consisting of adrenalectomy) or bilateral adrenal hyperplasia (subsequent treatment with mineralocorticoid receptor antagonists). The primary endpoint was the intensity of drug treatment for obtaining target blood pressure after 1 year of follow-up, in the intention-to-diagnose population. Intensity of drug treatment was expressed as daily defined doses. Key secondary endpoints included biochemical outcome in patients who received adrenalectomy, health-related quality of life, cost-effectiveness, and adverse events. This trial is registered with ClinicalTrials.gov, number NCT01096654. We recruited 200 patients between July 6, 2010, and May 30, 2013. Of the 184 patients that completed follow-up, 92 received CT-based treatment (46 adrenalectomy and 46 mineralocorticoid receptor antagonist) and 92 received AVS-based treatment (46 adrenalectomy and 46 mineralocorticoid receptor antagonist). We found no differences in the intensity of antihypertensive medication required to control blood pressure between patients with CT-based treatment and those with AVS-based treatment (median daily defined doses 3·0 [IQR 1·0-5·0] vs 3·0 [1·1-5·9], p=0·52; median number of drugs 2 [IQR 1-3] vs 2 [1-3], p=0·87). Target blood pressure was reached in 39 (42%) patients and 41 (45%) patients, respectively (p=0·82). On secondary endpoints we found no differences in health-related quality of

  4. Dietary sodium modulation of aldosterone activation and renal function during the progression of experimental heart failure.

    PubMed

    Miller, Wayne L; Borgeson, Daniel D; Grantham, J Aaron; Luchner, Andreas; Redfield, Margaret M; Burnett, John C

    2015-02-01

    Aldosterone activation is central to the sodium–fluid retention that marks the progression of heart failure (HF). The actions of dietary sodium restriction, a mainstay in HF management, on cardiorenal and neuroendocrine adaptations during the progression of HF are poorly understood. The study aim was to assess the role of dietary sodium during the progression of experimental HF. Experimental HF was produced in a canine model by rapid right ventricular pacing which evolves from early mild HF to overt, severe HF. Dogs were fed one of three diets: (i) high sodium [250 mEq (5.8 g) per day, n =6]; (ii) standard sodium [58 mEq (1.3 g) per day, n =6]; and (iii) sodium restriction [11 mEq (0.25 g) per day, n =6]. During the 38-day study, haemodynamics, renal function, plasma renin activity (PRA), and aldosterone were measured. Changes in haemodynamics at 38 days were similar in all three groups, as were changes in renal function. Aldosterone activation was demonstrated in all three groups; however, dietary sodium restriction, in contrast to high sodium, resulted in early (10 days) activation of PRA and aldosterone. High sodium demonstrated significant suppression of aldosterone activation over the course of HF progression. Excessive dietary sodium restriction particularly in early stage HF results in early aldosterone activation, while normal and excess sodium intake are associated with delayed or suppressed activation. These findings warrant evaluation in humans to determine if dietary sodium manipulation, particularly during early stage HF, may have a significant impact on neuroendocrine disease progression.

  5. Grape hexokinases are involved in the expression regulation of sucrose synthase- and cell wall invertase-encoding genes by glucose and ABA.

    PubMed

    Wang, Xiu-Qin; Zheng, Li-Li; Lin, Hao; Yu, Fei; Sun, Li-Hui; Li, Li-Mei

    2017-05-01

    Hexokinase (HXK, EC 2.7.1.1) is a multifunctional protein that both is involved in catalyzing the first step of glycolysis and plays an important role in sugar signaling. However, the supporting genetic evidence on hexokinases (CsHXKs) from grape (Vitis vinifera L. cv. Cabernet Sauvignon) berries has been lacking. Here, to investigate the role of CsHXK isoforms as glucose (Glc) and abscisic acid (ABA) sensors, we cloned two hexokinase isozymes, CsHXK1 and CsHXK2 with highly conserved genomic structure of nine exons and eight introns. We also found adenosine phosphate binding, substrate recognition and connection sites in their putative proteins. During grape berry development, the expression profiles of two CsHXK isoforms, sucrose synthases (SuSys) and cell wall invertase (CWINV) genes increased concomitantly with high levels of endogenous Glc and ABA. Furthermore, we showed that in wild type grape berry calli (WT), glucose repressed the expression levels of sucrose synthase (SuSy) and cell wall invertase (CWINV) genes, while ABA increased their expression levels. ABA could not only effectively improve the expression levels of SuSy and CWINV, but also block the repression induced by glucose on the expression of both genes. However, after silencing CsHXK1 or CsHXK2 in grape calli, SuSy and CWINV expression were enhanced, and the expressions of the two genes are insensitive in response to Glc treatment. Interestingly, exogenous ABA alone could not or less increase SuSy and CWINV expression in silencing CsHXK1 or CsHXK2 grape calli compared to WT. Meantime, ABA could not block the repression induced by glucose on the expression of SuSy and CWINV in CsHXK1 or CsHXK2 mutants. Therefore, Glc signal transduction depends on the regulation of CsHXK1 or CsHXK2. ABA signal was also disturbed by CsHXK1 or CsHXK2 silencing. The present results provide new insights into the regulatory role of Glc and ABA on the enzymes related to sugar metabolism in grape berry.

  6. Vascular endothelial growth factor and nitric oxide synthase expression in human tooth germ development.

    PubMed

    Mastrangelo, F; Sberna, M T; Tettamanti, L; Cantatore, G; Tagliabue, A; Gherlone, E

    2016-01-01

    Vascular Endothelia Growth Factor (VEGF) and Nitric Oxide Synthase (NOS) expression, were evaluated in human tooth germs at two different stages of embryogenesis, to clarify the role of angiogenesis during tooth tissue differentiation and growth. Seventy-two third molar germ specimens were selected during oral surgery. Thirty-six were in the early stage and 36 in the later stage of tooth development. The samples were evaluated with Semi-quantitative Reverse Transcription-Polymerase chain Reaction analyses (RT-PcR), Western blot analysis (WB) and immunohistochemical analysis. Western blot and immunohistochemical analysis showed a VEGF and NOS 1-2-3 positive reaction in all samples analysed. VEGF high positive decrease reaction was observed in stellate reticulum cells, ameloblast and odontoblast clusters in early stage compared to later stage of tooth germ development. Comparable VEGF expression was observed in endothelial cells of early and advanced stage growth. NOS1 and NOS3 expressions showed a high increased value in stellate reticulum cells, and ameloblast and odontoblast clusters in advanced stage compared to early stage of development. The absence or only moderate positive reaction of NOS2 was detected in all the different tissues. Positive NOS2 expression showed in advanced stage of tissue development compared to early stage. The action of VEGF and NOS molecules are important mediators of angiogenesis during dental tissue development. VEGF high positive expression in stellate reticulum cells in the early stage of tooth development compared to the later stage and the other cell types, suggests a critical role of the stellate reticulum during dental embryo-morphogenesis.

  7. Differential accumulation of β-carotene and tissue specific expression of phytoene synthase (MaPsy) gene in banana (Musa sp) cultivars.

    PubMed

    Dhandapani, R; Singh, V P; Arora, A; Bhattacharya, R C; Rajendran, Ambika

    2017-12-01

    An experiment was conducted with twelve major Indian banana cultivars to investigate the molecular relationship between the differential accumulation of β-carotene in peel and pulp of the banana fruit and carotenoid biosynthetic pathway genes. The high performance liquid chromatography showed that all banana cultivars accumulated two-three fold more β-carotene in non-edible portion of the banana fruit. However, Nendran , a famous orange fleshed cultivar of South India, had high β-carotene content (1362 µg/100 g) in edible pulp. The gene encoding Musa accuminata phytoene synthase ( MaPsy ) was successfully amplified using a pair of degenerate primers designed from Oncidium orchid. The deduced amino acid sequences shared a high level of identity to phytoene synthase gene from other plants. Gene expression analysis confirmed the presence of two isoforms ( MaPsy1 and MaPsy2 ) of MaPsy gene in banana fruits. Presence of two isoforms of MaPsy gene in peel and one in pulp confirmed the differential accumulation of β-carotene in banana fruits. However, Nendran accumulated more β-carotene in edible pulp due to presence of both the isoforms of MaPsy gene. Thus, carotenoid accumulation is a tissue specific process strongly dependent on differential expression pattern of two isoforms of MaPsy gene in banana.

  8. Optimization of left adrenal vein sampling in primary aldosteronism: Coping with asymmetrical cortisol secretion.

    PubMed

    Kishino, Mitsuhiro; Yoshimoto, Takanobu; Nakadate, Masashi; Katada, Yoshiaki; Kanda, Eiichiro; Nakaminato, Shuichiro; Saida, Yukihisa; Ogawa, Yoshihiro; Tateishi, Ukihide

    2017-03-31

    We evaluated the influence of catheter sampling position and size on left adrenal venous sampling (AVS) in patients with primary aldosteronism (PA) and analyzed their relationship to cortisol secretion. This retrospective study included 111 patients with a diagnosis of primary aldosteronism who underwent tetracosactide-stimulated AVS. Left AVS was obtained from two catheter positions - the central adrenal vein (CAV) and the common trunk. For common trunk sampling, 5-French catheters were used in 51 patients, and microcatheters were used in 60 patients. Autonomous cortisol secretion was evaluated with a low-dose dexamethasone suppression test in 87 patients. The adrenal/inferior vena cava cortisol concentration ratio [selectivity index (SI)] was significantly lower in samples from the left common trunk than those of the left CAV and right adrenal veins, but this difference was reduced when a microcatheter was used for common trunk sampling. Sample dilution in the common trunk of the left adrenal vein can be decreased by limiting sampling speed with the use of a microcatheter. Meanwhile, there was no significant difference in SI between the left CAV and right adrenal veins. Laterality, determined according to aldosterone/cortisol ratio (A/C ratio) based criteria, showed good reproducibility regardless of sampling position, unlike the absolute aldosterone value based criteria. However, in 11 cases with autonomous cortisol co-secretion, the cortisol hypersecreting side tended to be underestimated when using A/C ratio based criteria. Left CAV sampling enables symmetrical sampling, and may be essential when using absolute aldosterone value based criteria in cases where symmetrical cortisol secretion is uncertain.

  9. 5-Fluoroindole Resistance Identifies Tryptophan Synthase Beta Subunit Mutants in Arabidopsis Thaliana

    PubMed Central

    Barczak, A. J.; Zhao, J.; Pruitt, K. D.; Last, R. L.

    1995-01-01

    A study of the biochemical genetics of the Arabidopsis thaliana tryptophan synthase beta subunit was initiated by characterization of mutants resistant to the inhibitor 5-fluoroindole. Thirteen recessive mutations were recovered that are allelic to trp2-1, a mutation in the more highly expressed of duplicate tryptophan synthase beta subunit genes (TSB1). Ten of these mutations (trp2-2 through trp2-11) cause a tryptophan requirement (auxotrophs), whereas three (trp2-100 through trp2-102) remain tryptophan prototrophs. The mutations cause a variety of changes in tryptophan synthase beta expression. For example, two mutations (trp2-5 and trp2-8) cause dramatically reduced accumulation of TSB mRNA and immunologically detectable protein, whereas trp2-10 is associated with increased mRNA and protein. A correlation exists between the quantity of mutant beta and wild-type alpha subunit levels in the trp2 mutant plants, suggesting that the synthesis of these proteins is coordinated or that the quantity or structure of the beta subunit influences the stability of the alpha protein. The level of immunologically detectable anthranilate synthase alpha subunit protein is increased in the trp2 mutants, suggesting the possibility of regulation of anthranilate synthase levels in response to tryptophan limitation. PMID:7635295

  10. Pathological Lesions and Inducible Nitric Oxide Synthase Expressions in the Liver of Mice Experimentally Infected with Clonorchis sinensis.

    PubMed

    Yang, Qing-Li; Shen, Ji-Qing; Xue, Yan; Cheng, Xiao-Bing; Jiang, Zhi-Hua; Yang, Yi-Chao; Chen, Ying-Dan; Zhou, Xiao-Nong

    2015-12-01

    The nitric oxide (NO) formation and intrinsic nitrosation may be involved in the possible mechanisms of liver fluke-associated carcinogenesis. We still do not know much about the responses of inducible NO synthase (iNOS) induced by Clonorchis sinensis infection. This study was conducted to explore the pathological lesions and iNOS expressions in the liver of mice with different infection intensity levels of C. sinensis. Extensive periductal inflammatory cell infiltration, bile duct hyperplasia, and fibrosis were commonly observed during the infection. The different pathological responses in liver tissues strongly correlated with the infection intensity of C. sinensis. Massive acute spotty necrosis occurred in the liver parenchyma after a severe infection. The iNOS activity in liver tissues increased, and iNOS-expressing cells with morphological differences were observed after a moderate or severe infection. The iNOS-expressing cells in liver tissues had multiple origins.

  11. In Planta Recapitulation of Isoprene Synthase Evolution from Ocimene Synthases.

    PubMed

    Li, Mingai; Xu, Jia; Algarra Alarcon, Alberto; Carlin, Silvia; Barbaro, Enrico; Cappellin, Luca; Velikova, Violeta; Vrhovsek, Urska; Loreto, Francesco; Varotto, Claudio

    2017-10-01

    Isoprene is the most abundant biogenic volatile hydrocarbon compound naturally emitted by plants and plays a major role in atmospheric chemistry. It has been proposed that isoprene synthases (IspS) may readily evolve from other terpene synthases, but this hypothesis has not been experimentally investigated. We isolated and functionally validated in Arabidopsis the first isoprene synthase gene, AdoIspS, from a monocotyledonous species (Arundo donax L., Poaceae). Phylogenetic reconstruction indicates that AdoIspS and dicots isoprene synthases most likely originated by parallel evolution from TPS-b monoterpene synthases. Site-directed mutagenesis demonstrated invivo the functional and evolutionary relevance of the residues considered diagnostic for IspS function. One of these positions was identified by saturating mutagenesis as a major determinant of substrate specificity in AdoIspS able to cause invivo a dramatic change in total volatile emission from hemi- to monoterpenes and supporting evolution of isoprene synthases from ocimene synthases. The mechanism responsible for IspS neofunctionalization by active site size modulation by a single amino acid mutation demonstrated in this study might be general, as the very same amino acidic position is implicated in the parallel evolution of different short-chain terpene synthases from both angiosperms and gymnosperms. Based on these results, we present a model reconciling in a unified conceptual framework the apparently contrasting patterns previously observed for isoprene synthase evolution in plants. These results indicate that parallel evolution may be driven by relatively simple biophysical constraints, and illustrate the intimate molecular evolutionary links between the structural and functional bases of traits with global relevance. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  12. UVB light upregulates prostaglandin synthases and prostaglandin receptors in mouse keratinocytes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Black, Adrienne T.; Gray, Joshua P.; Shakarjian, Michael P.

    Prostaglandins belong to a class of cyclic lipid-derived mediators synthesized from arachidonic acid via COX-1, COX-2 and various prostaglandin synthases. Members of this family include prostaglandins such as PGE{sub 2}, PGF{sub 2{alpha}}, PGD{sub 2} and PGI{sub 2} (prostacyclin) as well as thromboxane. In the present studies we analyzed the effects of UVB on prostaglandin production and prostaglandin synthase expression in primary cultures of undifferentiated and calcium-differentiated mouse keratinocytes. Both cell types were found to constitutively synthesize PGE{sub 2}, PGD{sub 2} and the PGD{sub 2} metabolite PGJ{sub 2}. Twenty-four hours after treatment with UVB (25 mJ/cm{sup 2}), production of PGE{sub 2}more » and PGJ{sub 2} increased, while PGD{sub 2} production decreased. This was associated with increased expression of COX-2 mRNA and protein. UVB (2.5-25 mJ/cm{sup 2}) also caused marked increases in mRNA expression for the prostanoid synthases PGDS, mPGES-1, mPGES-2, PGFS and PGIS, as well as expression of receptors for PGE{sub 2} (EP1 and EP2), PGD{sub 2} (DP and CRTH2) and prostacyclin (IP). UVB was more effective in inducing COX-2 and DP in differentiated cells and EP1 and IP in undifferentiated cells. UVB readily activated keratinocyte PI-3-kinase (PI3K)/Akt, JNK and p38 MAP signaling pathways which are known to regulate COX-2 expression. While inhibition of PI3K suppressed UVB-induced mPGES-1 and CRTH2 expression, JNK inhibition suppressed mPGES-1, PGIS, EP2 and CRTH2, and p38 kinase inhibition only suppressed EP1 and EP2. These data indicate that UVB modulates expression of prostaglandin synthases and receptors by distinct mechanisms. Moreover, both the capacity of keratinocytes to generate prostaglandins and their ability to respond to these lipid mediators are stimulated by exposure to UVB.« less

  13. Antiapolipoprotein A-1 IgG chronotropic effects require nongenomic action of aldosterone on L-type calcium channels.

    PubMed

    Rossier, Michel F; Pagano, Sabrina; Python, Magaly; Maturana, Andres D; James, Richard W; Mach, François; Roux-Lombard, Pascale; Vuilleumier, Nicolas

    2012-03-01

    Autoantibodies to apolipoprotein A-1 (antiapoA-1 IgG) have been shown to be associated with higher resting heart rate and morbidity in myocardial infarction patients and to behave as a chronotropic agent in the presence of aldosterone on isolated neonatal rat ventricular cardiomyocytes (NRVC). We aimed at identifying the pathways accounting for this aldosterone-dependent antiapoA-1 IgG-positive chronotropic effect on NRVC. The rate of regular spontaneous contractions was determined on NRVC in the presence of different steroid hormones and antagonists. AntiapoA-1 IgG chronotropic response was maximal within 20 min and observed only in aldosterone-pretreated cells but not in those exposed to other steroids. The positive antiapoA-1 IgG chronotropic effect was already significant after 5 min aldosterone preincubation, was dependent on 3-kinase and protein kinase A activities, was not inhibited by actinomycin D, and was fully abrogated by eplerenone (but not by spironolactone), demonstrating the dependence on a nongenomic action of aldosterone elicited through the mineralocorticoid receptor (MR). Under oxidative conditions (but not under normal redox state), corticosterone mimicked the permissive action of aldosterone on the antiapoA-1 IgG chronotropic response. Pharmacological and patch-clamp studies identified L-type calcium channels as crucial effectors of antiapoA-1 IgG chronotropic action, involving two converging pathways that increase the channel activity. The first one involves the rapid, nongenomic activation of the phosphatidylinositol 3-kinase enzyme by MR, and the second one requires a constitutive basal protein kinase A activity. In conclusion, our results indicate that, on NRVC, the aldosterone-dependent chronotropic effects of antiapoA-1 IgG involve the nongenomic activation of L-type calcium channels.

  14. Inhibition of the renin-angiotensin-aldosterone system: is there room for dual blockade in the cardiorenal continuum?

    PubMed

    Volpe, Massimo; Danser, A H Jan; Menard, Joël; Waeber, Bernard; Mueller, Dominik N; Maggioni, Aldo P; Ruilope, Luis M

    2012-04-01

    Antagonism of renin-angiotensin-aldosterone system is exerted through angiotensin-converting enzyme inhibitors, angiotensin receptor antagonists, renin inhibitors and mineralocorticoid receptor antagonists. These drugs have been successfully tested in numerous trials and in different clinical settings. The original indications of renin-angiotensin-aldosterone system blockers have progressively expanded from the advanced stages to the earlier stages of cardiorenal continuum. To optimize the degree of blockade of renin-angiotensin-aldosterone system, dose uptitrations of angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists or the use of a dual blockade, initially identified with the combination of angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists, have been proposed. The data from the Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET) study do not support this specific dual blockade approach. However, the dual blockade of angiotensin-converting enzyme inhibitors/angiotensin receptor antagonists with direct renin inhibitors is currently under investigation while that based on an aldosterone blocker with any of the previous three drugs requires more evidence beyond heart failure. In this review, we revisited potential advantages of dual blockade of renin-angiotensin-aldosterone system in arterial hypertension and diabetes.

  15. Expression of thymidylate synthase and glutathione-s-transferase pi in patients with esophageal squamous cell carcinoma.

    PubMed

    Huang, Jun-Xing; Li, Feng-Yue; Xiao, Wei; Song, Zheng-Xiang; Qian, Rong-Yu; Chen, Ping; Salminen, Eeva

    2009-09-14

    To investigate the expression of thymidylate synthase (TS) and glutathione-s-transferase pi (GST-pi) in esophageal squamous cell carcinoma and their association with the clinicopathologic characteristics. Immunohistochemical methods were used to detect the expression of TS and GST-pi in surgically resected formalin-fixed, paraffin-embedded esophageal squamous cell carcinoma (ESCC) tissue sections from 102 patients (median age, 58 years) and in 28 normal esophageal mucosa (NEM) samples. The relationship between TS and GST-pi expression and clinicopathologic factors was examined. The expression of TS and GST-pi was not statistically significantly associated with age of the patients, tumor size, lymph node metastasis, depth of invasion or tumor stage. TS staining was positive in 17.86% of normal esophageal mucosa and in 42.16% of ESCC samples (P < 0.05). The expression level of TS was not only significantly lower in well-differentiated (21.88%) than in poorly-differentiated carcinomas (51.43%, P < 0.05), but was also significantly higher in samples from male patients (46.51%) than from female patients (18.75%, P < 0.05). GST-pi was positively stained in 78.57% of normal esophageal mucosa and in 53.92% of ESCC samples (P < 0.05). The expression level of GST-pi was also significantly higher in well-differentiated carcinomas (65.63%) than in poorly-differentiated carcinomas (35.00%, P < 0.05). The expression of TS and of GST-pi may be used as molecular markers for the characterization of ESCC. Poorly-differentiated cells showed increased expression of TS and reduced expression of GST-pi.

  16. Identification and expression profile analysis of the sucrose phosphate synthase gene family in Litchi chinensis Sonn.

    PubMed Central

    Wang, Dan; Zhao, Jietang; Hu, Bing; Li, Jiaqi; Qin, Yaqi; Chen, Linhuan; Qin, Yonghua

    2018-01-01

    Sucrose phosphate synthase (SPS, EC 2.4.1.14) is a key enzyme that regulates sucrose biosynthesis in plants. SPS is encoded by different gene families which display differential expression patterns and functional divergence. Genome-wide identification and expression analyses of SPS gene families have been performed in Arabidopsis, rice, and sugarcane, but a comprehensive analysis of the SPS gene family in Litchi chinensis Sonn. has not yet been reported. In the current study, four SPS gene (LcSPS1, LcSPS2, LcSPS3, and LcSPS4) were isolated from litchi. The genomic organization analysis indicated the four litchi SPS genes have very similar exon-intron structures. Phylogenetic tree showed LcSPS1-4 were grouped into different SPS families (LcSPS1 and LcSPS2 in A family, LcSPS3 in B family, and LcSPS4 in C family). LcSPS1 and LcSPS4 were strongly expressed in the flowers, while LcSPS3 most expressed in mature leaves. RT-qPCR results showed that LcSPS genes expressed differentially during aril development between cultivars with different hexose/sucrose ratios. A higher level of expression of LcSPS genes was detected in Wuheli, which accumulates higher sucrose in the aril at mature. The tissue- and developmental stage-specific expression of LcSPS1-4 genes uncovered in this study increase our understanding of the important roles played by these genes in litchi fruits. PMID:29473005

  17. UVB-irradiated keratinocytes induce melanoma-associated ganglioside GD3 synthase gene in melanocytes via secretion of tumor necrosis factor α and interleukin 6

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Miyata, Maiko; Department of Biochemistry II, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-ku, Nagoya 466-0065; Ichihara, Masatoshi

    Highlights: • Melanocytes showed low ST8SIA1 and high B3GALT4 levels in contrast with melanomas. • Direct UVB irradiation of melanocytes did not induce ganglioside synthase genes. • Culture supernatants of UVB-irradiated keratinocytes induced ST8SIA1 in melanocytes. • TNFα and IL-6 secreted from keratinocytes enhanced ST8SIA1 expression in melanocytes. • Inflammatory cytokines induced melanoma-related ST8SIA1 in melanocytes. - Abstract: Although expression of gangliosides and their synthetic enzyme genes in malignant melanomas has been well studied, that in normal melanocytes has been scarcely analyzed. In particular, changes in expression levels of glycosyltransferase genes responsible for ganglioside synthesis during evolution of melanomas frommore » melanocytes are very important to understand roles of gangliosides in melanomas. Here, expression of glycosyltransferase genes related to the ganglioside synthesis was analyzed using RNAs from cultured melanocytes and melanoma cell lines. Quantitative RT-PCR revealed that melanomas expressed high levels of mRNA of GD3 synthase and GM2/GD2 synthase genes and low levels of GM1/GD1b synthase genes compared with melanocytes. As a representative exogenous stimulation, effects of ultraviolet B (UVB) on the expression levels of 3 major ganglioside synthase genes in melanocytes were analyzed. Although direct UVB irradiation of melanocytes caused no marked changes, culture supernatants of UVB-irradiated keratinocytes (HaCaT cells) induced definite up-regulation of GD3 synthase and GM2/GD2 synthase genes. Detailed examination of the supernatants revealed that inflammatory cytokines such as TNFα and IL-6 enhanced GD3 synthase gene expression. These results suggest that inflammatory cytokines secreted from UVB-irradiated keratinocytes induced melanoma-associated ganglioside synthase genes, proposing roles of skin microenvironment in the promotion of melanoma-like ganglioside profiles in melanocytes.« less

  18. Persistent Primary Aldosteronism Despite Iatrogenic Adrenal Hemorrhage After Adrenal Vein Sampling

    PubMed Central

    Okamura, Keisuke; Okuda, Tetsu; Shirai, Kazuyuki; Abe, Ichiro; Kobayashi, Kunihisa; Ishii, Tatsu; Haraoka, Seiji; Urata, Hidenori

    2018-01-01

    Before surgery for primary aldosteronism (PA), localization is evaluated with adrenal vein sampling (AVS). A 56-year-old Japanese woman had a right adrenal mass, hypokalemia, and a high aldosterone/renin ratio. Stress tests confirmed the diagnosis of PA. Subsequently, preoperative AVS was performed and right adrenal hemorrhage (AH) occurred unexpectedly. Because hypertension persisted, laparoscopic right adrenalectomy was performed. Postoperatively, the blood pressure was normalized. Pathological examination revealed an adrenal cortical adenoma largely unaffected by necrosis and hemorrhage. Previous reports have also indicated that AH may not ameliorate PA. We discussed the clinical progress of AH and the measures to prevent causing AH. PMID:29238437

  19. Study Heterogeneity and Estimation of Prevalence of Primary Aldosteronism: A Systematic Review and Meta-Regression Analysis.

    PubMed

    Käyser, Sabine C; Dekkers, Tanja; Groenewoud, Hans J; van der Wilt, Gert Jan; Carel Bakx, J; van der Wel, Mark C; Hermus, Ad R; Lenders, Jacques W; Deinum, Jaap

    2016-07-01

    For health care planning and allocation of resources, realistic estimation of the prevalence of primary aldosteronism is necessary. Reported prevalences of primary aldosteronism are highly variable, possibly due to study heterogeneity. Our objective was to identify and explain heterogeneity in studies that aimed to establish the prevalence of primary aldosteronism in hypertensive patients. PubMed, EMBASE, Web of Science, Cochrane Library, and reference lists from January 1, 1990, to January 31, 2015, were used as data sources. Description of an adult hypertensive patient population with confirmed diagnosis of primary aldosteronism was included in this study. Dual extraction and quality assessment were the forms of data extraction. Thirty-nine studies provided data on 42 510 patients (nine studies, 5896 patients from primary care). Prevalence estimates varied from 3.2% to 12.7% in primary care and from 1% to 29.8% in referral centers. Heterogeneity was too high to establish point estimates (I(2) = 57.6% in primary care; 97.1% in referral centers). Meta-regression analysis showed higher prevalences in studies 1) published after 2000, 2) from Australia, 3) aimed at assessing prevalence of secondary hypertension, 4) that were retrospective, 5) that selected consecutive patients, and 6) not using a screening test. All studies had minor or major flaws. This study demonstrates that it is pointless to claim low or high prevalence of primary aldosteronism based on published reports. Because of the significant impact of a diagnosis of primary aldosteronism on health care resources and the necessary facilities, our findings urge for a prevalence study whose design takes into account the factors identified in the meta-regression analysis.

  20. The Relationship Between the Renin-Angiotensin-Aldosterone System and NMDA Receptor-Mediated Signal and the Prevention of Retinal Ganglion Cell Death.

    PubMed

    Kobayashi, Mamoru; Hirooka, Kazuyuki; Ono, Aoi; Nakano, Yuki; Nishiyama, Akira; Tsujikawa, Akitaka

    2017-03-01

    Excitotoxicity, which is due to glutamate-induced toxic effects on the retinal ganglion cell (RGC), is one of several mechanisms of RGC loss. The renin-angiotensin-aldosterone system (RAAS) has also been implicated in RGC death. Therefore, it is important to determine the exact relationship between the RAAS and N-methyl-d-aspartate (NMDA) receptor-mediated signal in order to prevent RGC death. N-methyl-d-aspartate or aldosterone was injected into the vitreous body. After intravitreal injection of NMDA or aldosterone, animals were treated with spironolactone or memantine. Retinal damage was evaluated by measuring the number of RGCs at 4 weeks after local administration of aldosterone or at 2 weeks after local administration of NMDA. Vitreous humor levels of aldosterone were measured using enzyme immunoassay kits. A significantly decreased number of RGCs were observed after intravitreal injection of NMDA. Although spironolactone did not show any neuroprotective effects, memantine significantly reduced NMDA-induced degeneration in the retina. Furthermore, a significant decrease in the number of RGCs was observed after an intravitreal injection of aldosterone. While memantine did not exhibit any neuroprotective effects, spironolactone caused a significant reduction in the aldosterone-induced degeneration in the retina. There was no change in the aldosterone concentration in the vitreous humor after an NMDA injection. Our findings indirectly show that there is no relationship between the RAAS and NMDA receptor-mediated signal with regard to RGC death.