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Sample records for aldosterone mediates activation

  1. Mitochondrial reactive oxygen species-mediated NLRP3 inflammasome activation contributes to aldosterone-induced renal tubular cells injury.

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    Ding, Wei; Guo, Honglei; Xu, Chengyan; Wang, Bin; Zhang, Minmin; Ding, Feng

    2016-04-01

    Aldosterone (Aldo) is an independent risk factor for chronic kidney disease (CKD), and although Aldo directly induces renal tubular cell injury, the underlying mechanisms remain unclear. NLRP3 inflammasome and mitochondrial reactive oxygen species (ROS) have recently been implicated in various kinds of CKD. The present study hypothesized that mitochondrial ROS and NLRP3 inflammasome mediated Aldo-induced tubular cell injury. The NLRP3 inflammasome is induced by Aldo in a dose- and time-dependent manner, as evidenced by increased NLRP3, ASC, caspase-1, and downstream cytokines, such as interleukin (IL)-1β and IL-18. The activation of the NLRP3 inflammasome was significantly prevented by the selective mineralocorticoid receptor (MR) antagonist eplerenone (EPL) (P < 0.01). Mice harboring genetic knock-out of NLRP3 (NLRP3(-/-)) showed decreased maturation of renal IL-1β and IL-18, reduced renal tubular apoptosis, and improved renal epithelial cell phenotypic alternation, and attenuated renal function in response to Aldo-infusion. In addition, mitochondrial ROS was also increased in Aldo-stimulated HK-2 cells, as assessed by MitoSOXTM red reagent. Mito-Tempo, the mitochondria-targeted antioxidant, significantly decreased HK-2 cell apoptosis, oxidative stress, and the activation of NLRP3 inflammasome. We conclude that Aldo induces renal tubular cell injury via MR dependent, mitochondrial ROS-mediated NLRP3 inflammasome activation. PMID:27014913

  2. Mitochondrial reactive oxygen species-mediated NLRP3 inflammasome activation contributes to aldosterone-induced renal tubular cells injury

    Science.gov (United States)

    Ding, Wei; Guo, Honglei; Xu, Chengyan; Wang, Bin; Zhang, Minmin; Ding, Feng

    2016-01-01

    Aldosterone (Aldo) is an independent risk factor for chronic kidney disease (CKD), and although Aldo directly induces renal tubular cell injury, the underlying mechanisms remain unclear. NLRP3 inflammasome and mitochondrial reactive oxygen species (ROS) have recently been implicated in various kinds of CKD. The present study hypothesized that mitochondrial ROS and NLRP3 inflammasome mediated Aldo–induced tubular cell injury. The NLRP3 inflammasome is induced by Aldo in a dose- and time-dependent manner, as evidenced by increased NLRP3, ASC, caspase-1, and downstream cytokines, such as interleukin (IL)-1β and IL-18. The activation of the NLRP3 inflammasome was significantly prevented by the selective mineralocorticoid receptor (MR) antagonist eplerenone (EPL) (P < 0.01). Mice harboring genetic knock-out of NLRP3 (NLRP3−/−) showed decreased maturation of renal IL-1β and IL-18, reduced renal tubular apoptosis, and improved renal epithelial cell phenotypic alternation, and attenuated renal function in response to Aldo-infusion. In addition, mitochondrial ROS was also increased in Aldo-stimulated HK-2 cells, as assessed by MitoSOXTM red reagent. Mito-Tempo, the mitochondria-targeted antioxidant, significantly decreased HK-2 cell apoptosis, oxidative stress, and the activation of NLRP3 inflammasome. We conclude that Aldo induces renal tubular cell injury via MR dependent, mitochondrial ROS-mediated NLRP3 inflammasome activation. PMID:27014913

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

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

    2016-07-01

    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 (0.2 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. PMID:27040306

  4. Endocrine effects of lithium. III. Hypermagnesaemia and activation of the renin-aldosterone system.

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    Transbøl, I; Christiansen, C; Baastrup, P C; Nielsen, M D; Giese, J

    1978-07-01

    Hypermagnesaemia is a well-known but as yet unexplained concomitant of lithium treatment. Prior suggestions implicating a role for aldosterone in magnesium homoeostasis prompted this study of plasma renin, plasma aldosterone and serum magnesium in 17 maniodepressive patients on long-term lithium treatment. In addition to hypermagnesaemia (P less than 0.001), this group of patients had raised plasma levels of aldosterone (P less than 0.001) and increased plasma renin concentration (P less than 0.05). Serum magnesium was positively correlated to plasma aldosterone (r = 0.58, P less than 0.02). The relation between activation of the renin-aldosterone system and the presence of hypermagnesaemia during chronic lithium treatment could conceivably be mediated through a lithium-induced hypovolaemic state. PMID:581026

  5. Active renin mass concentration to determine aldosterone-to-renin ratio in screening for primary aldosteronism

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    Corbin F

    2011-07-01

    Full Text Available François Corbin1, Pierre Douville2, Marcel Lebel3 1Division of Biochemistry, l'Université de Sherbrooke, Sherbrooke, Quebec, Canada; 2Division of Biochemistry; 3Division of Nephrology, L'Hôtel-Dieu de Québec Hospital and l'Université Laval, Quebec, CanadaBackground: Active renin mass concentration (ARC is independent of the endogenous level of angiotensinogen, and less variable and more reproducible than plasma renin activity. Reference values for the aldosterone-to-renin ratio (ARR using ARC are still undefined. The objective of the present study was to determine the threshold of ARR using ARC measurement to screen for primary aldosteronism.Methods: A total of 211 subjects were included in the study, comprising 78 healthy normotensive controls, 95 patients with essential hypertension, and 38 patients with confirmed primary aldosteronism (20 with surgery-confirmed aldosterone-producing adenoma and 18 with idiopathic adrenal hyperplasia. Blood samples were drawn from ambulatory patients and volunteers in the mid-morning without specific dietary restriction for measuring plasma aldosterone concentration, ARC, and serum potassium.Results: Most normotensive controls and essential hypertension patients had ARR results below 100 pmol/ng, a value which corresponded to 3.3 times the median of these two groups.Conclusion: Patients with ARR values above this level should be considered for further investigation (confirmatory tests or for repeat testing should ARR values be borderline. This study indicates that ARC can be used reliably in determining ARR for primary aldosteronism screening.Keywords: primary aldosteronism, active renin mass concentration, aldosterone-to-renin ratio

  6. Calcium channel blocker prevents stress-induced activation of renin and aldosterone in conscious pig

    International Nuclear Information System (INIS)

    A considerable amount of data suggest the involvement of calcium-mediated processes in the activation of the renin-angiotensin-aldosterone (RAA) cascade. To investigate the effect of calcium-channel inhibition on the RAA system, the authors studied 21 conscious pigs. Blood renin and aldosterone levels increased by subjecting animals to 24 hours of immobilization stress. Renin and aldosterone levels were repeatedly measured by radioimmunoassay in blood samples taken periodically over 24 hours from a chronically implanted arterial cannula. Pretreatment of the animals (N = 11) with nisoldipine, 2 x 20 mg p.o. daily for 2 days before and on the day of immobilization, transiently attenuated the stress-induced increase of plasma renin activity and completely prevented the rise of aldosterone, as compared to nontreated controls (N = 10). The finding that nisoldipine suppresses RAA activation induced by a nonpharmacologic stimulus in the conscious intact animal may have clinical implications

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

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    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. PMID:27222295

  8. Drug effects on aldosterone/plasma renin activity ratio in primary aldosteronism.

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    Mulatero, Paolo; Rabbia, Franco; Milan, Alberto; Paglieri, Cristina; Morello, Fulvio; Chiandussi, Livio; Veglio, Franco

    2002-12-01

    Primary aldosteronism is a specifically treatable and potentially curable form of secondary hypertension. The aldosterone/plasma renin activity ratio (ARR) is routinely used as a screening test. Antihypertensive therapy can interfere with the interpretation of this parameter, but a correct washout period can be potentially harmful. We have investigated the effects of therapy with atenolol, amlodipine, doxazosin, fosinopril, and irbesartan on the ARR in a group of 230 patients with suspected primary aldosteronism. The percent change from control of ARR in patients taking amlodipine was -17%+/-32; atenolol, 62%+/-82; doxazosin, -5%+/-26; fosinopril, -30%+/-24; and irbesartan, -43%+/-27. The ARR change induced by atenolol was significantly higher compared with that induced by all other drugs (P<0.0001), and the ARR change induced by irbesartan was significantly lower than that induced by doxazosin (P<0.0001). One of 55 patients from the group taking amlodipine (1.8%) and 4/17 of the patients taking irbesartan (23.5%) gave a false-negative ARR (<50). None of the patients of the groups taking fosinopril, doxazosin, and atenolol displayed a false-negative ARR. Doxazosin and fosinopril can be used in hypertensive patients who need to undergo aldosterone and PRA measurement for the diagnosis of primary aldosteronism; amlodipine gave a very small percentage of false-negative diagnoses. beta-Blockers also do not interfere with the diagnosis of primary aldosteronism, but they can be responsible for an increased rate of false-positive ARRs. The high rate of false-negative diagnoses in patients undergoing irbesartan treatment requires confirmation in a higher number of patients. PMID:12468576

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

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    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. PMID:26054365

  10. Activating mutations in CTNNB1 in aldosterone producing adenomas.

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    Åkerström, Tobias; Maharjan, Rajani; Sven Willenberg, Holger; Cupisti, Kenko; Ip, Julian; Moser, Ana; Stålberg, Peter; Robinson, Bruce; Alexander Iwen, K; Dralle, Henning; Walz, Martin K; Lehnert, Hendrik; Sidhu, Stan; Gomez-Sanchez, Celso; Hellman, Per; Björklund, Peyman

    2016-01-01

    Primary aldosteronism (PA) is the most common cause of secondary hypertension with a prevalence of 5-10% in unreferred hypertensive patients. Aldosterone producing adenomas (APAs) constitute a large proportion of PA cases and represent a surgically correctable form of the disease. The WNT signaling pathway is activated in APAs. In other tumors, a frequent cause of aberrant WNT signaling is mutation in the CTNNB1 gene coding for β-catenin. Our objective was to screen for CTNNB1 mutations in a well-characterized cohort of 198 APAs. Somatic CTNNB1 mutations were detected in 5.1% of the tumors, occurring mutually exclusive from mutations in KCNJ5, ATP1A1, ATP2B3 and CACNA1D. All of the observed mutations altered serine/threonine residues in the GSK3β binding domain in exon 3. The mutations were associated with stabilized β-catenin and increased AXIN2 expression, suggesting activation of WNT signaling. By CYP11B2 mRNA expression, CYP11B2 protein expression, and direct measurement of aldosterone in tumor tissue, we confirmed the ability for aldosterone production. This report provides compelling evidence that aberrant WNT signaling caused by mutations in CTNNB1 occur in APAs. This also suggests that other mechanisms that constitutively activate the WNT pathway may be important in APA formation. PMID:26815163

  11. Activating mutations in CTNNB1 in aldosterone producing adenomas

    Science.gov (United States)

    Åkerström, Tobias; Maharjan, Rajani; Sven Willenberg, Holger; Cupisti, Kenko; Ip, Julian; Moser, Ana; Stålberg, Peter; Robinson, Bruce; Alexander Iwen, K.; Dralle, Henning; Walz, Martin K.; Lehnert, Hendrik; Sidhu, Stan; Gomez-Sanchez, Celso; Hellman, Per; Björklund, Peyman

    2016-01-01

    Primary aldosteronism (PA) is the most common cause of secondary hypertension with a prevalence of 5–10% in unreferred hypertensive patients. Aldosterone producing adenomas (APAs) constitute a large proportion of PA cases and represent a surgically correctable form of the disease. The WNT signaling pathway is activated in APAs. In other tumors, a frequent cause of aberrant WNT signaling is mutation in the CTNNB1 gene coding for β-catenin. Our objective was to screen for CTNNB1 mutations in a well-characterized cohort of 198 APAs. Somatic CTNNB1 mutations were detected in 5.1% of the tumors, occurring mutually exclusive from mutations in KCNJ5, ATP1A1, ATP2B3 and CACNA1D. All of the observed mutations altered serine/threonine residues in the GSK3β binding domain in exon 3. The mutations were associated with stabilized β-catenin and increased AXIN2 expression, suggesting activation of WNT signaling. By CYP11B2 mRNA expression, CYP11B2 protein expression, and direct measurement of aldosterone in tumor tissue, we confirmed the ability for aldosterone production. This report provides compelling evidence that aberrant WNT signaling caused by mutations in CTNNB1 occur in APAs. This also suggests that other mechanisms that constitutively activate the WNT pathway may be important in APA formation. PMID:26815163

  12. Chronic Aldosterone Administration Causes NOX2-Mediated Increases In Reactive Oxygen Species Production and Endothelial Dysfunction in the Cerebral Circulation

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    CHRISSOBOLIS, Sophocles; DRUMMOND, Grant R.; FARACI, Frank M.; SOBEY, Christopher G.

    2014-01-01

    Objective An elevated plasma aldosterone level is an independent cardiovascular risk factor. Although excess aldosterone promotes cardiovascular disease, no studies have examined the effect of increased plasma aldosterone on the cerebral circulation. A major source of vascular reactive oxygen species (ROS) during cardiovascular disease is the NADPH oxidases. Because NOX2-containing NADPH oxidase (NOX2 oxidase) is highly expressed in cerebral endothelium, we postulated that it might contribute to ROS generation and vascular dysfunction in response to aldosterone. Here we examined the effect of aldosterone and NOX2 oxidase on ROS production and endothelial dysfunction in the cerebral circulation, and whether the effects of aldosterone are exacerbated in aged mice. Methods and Results In adult (average age ~24–25 wk) wild-type (WT) and Nox2-deficient (Nox2−/y) mice, neither vehicle nor aldosterone (0.28 mg/kg/day for 14 days) affected blood pressure (measured using tail-cuff). By contrast, aldosterone treatment reduced dilation of the basilar artery (measured using myography) to the endothelium-dependent agonist acetylcholine in WT mice (P0.05). Aldosterone increased basal and phorbol-dibutyrate stimulated superoxide production (measured using L-012-enhanced chemiluminesence) in cerebral arteries from WT but not Nox2−/y mice. In aged WT mice (average age ~70 wk), aldosterone treatment increased blood pressure, but had a similar effect on cerebral artery superoxide levels as in adult WT mice. Conclusions These data indicate that NOX2 oxidase mediates aldosterone-induced increases in ROS production and endothelial dysfunction in cerebral arteries from adult mice independently of blood pressure changes. Aldosterone-induced hypertension is augmented during aging. PMID:24991871

  13. Aldosterone-induced oxidative stress and inflammation in the brain are mediated by the endothelial cell mineralocorticoid receptor.

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    Dinh, Quynh N; Young, Morag J; Evans, Megan A; Drummond, Grant R; Sobey, Christopher G; Chrissobolis, Sophocles

    2016-04-15

    Elevated aldosterone levels, which promote cerebral vascular oxidative stress, inflammation, and endothelial dysfunction, may increase stroke risk, independent of blood pressure and other risk factors. The main target receptor of aldosterone, the mineralocorticoid receptor (MR), is expressed in many cell types, including endothelial cells. Endothelial cell dysfunction is thought to be an initiating step contributing to cardiovascular disease and stroke; however the importance of MR expressed on endothelial cells in the brain is unknown. Here we have examined whether endothelial cell MR mediates cerebral vascular oxidative stress and brain inflammation during aldosterone excess. In male mice, aldosterone (0.72mg/kg/day, 14 days) caused a small increase (~14mmHg) in blood pressure. The MR blocker spironolactone (25mg/kg/d, ip) abolished this increase, whereas endothelial cell MR-deficiency had no effect. Aldosterone increased superoxide production capacity in cerebral arteries, and also mRNA expression of the pro-inflammatory cytokines chemokine (C-C motif) ligand 7 (CCL7), CCL8 and interleukin (IL)-1β in the brain. These increases were prevented by both spironolactone treatment and endothelial cell MR-deficiency; whereas IL-1β expression was blocked by spironolactone only. Endothelial cell MR mediates aldosterone-induced increases in cerebrovascular superoxide levels and chemokine expression in the brain, but not blood pressure or brain IL-1β. Endothelial cell-targeted MR antagonism may represent a novel approach to treat cerebrovascular disease and stroke, particularly during conditions of aldosterone excess. PMID:26923165

  14. Polycystic ovary syndrome: Implications of measurement of plasma aldosterone, renin activity and progesterone.

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    Armanini, Decio; Bordin, Luciana; Donà, Gabriella; Sabbadin, Chiara; Bakdounes, Leila; Ragazzi, Eugenio; Giorgino, Francesco L; Fiore, Cristina

    2012-05-01

    A positive correlation between aldosterone, inflammatory parameters, blood pressure and metabolic abnormalities in polycystic ovary syndrome (PCOS) has been reported in the early estrogenic phase. The aim of the study was to measure plasma aldosterone, plasma renin activity (PRA) and progesterone on the 21st day of the cycle, in women with PCOS and to consider the interrelationships between these hormones. Sixty-six consecutive normal BMI women with PCOS (median age 24 years, range 21-28 years) and 53 age- and body mass index-matched healthy controls were enrolled in the study. Aldosterone, aldosterone/PRA ratio (ARR) and Homeostasis Model Assessment (HOMA) index were significantly higher (p<0.0001) in PCOS women than controls. Positive correlations were found in PCOS but not in controls between (i) progesterone and aldosterone, (ii) aldosterone and PRA, (iii) PRA and progesterone. Mean blood pressures were within the normal range but significantly higher in PCOS than controls. The increase of plasma aldosterone, ARR and blood pressure in PCOS compared with controls is consistent with an increased mineralocorticoid effector mechanism in PCOS; prolonged therapy with spironolactone could counteract both the hyperandrogenism and reduce future cardiovascular risk. PMID:22387621

  15. Protein kinase D1 modulates aldosterone-induced ENaC activity in a renal cortical collecting duct cell line.

    LENUS (Irish Health Repository)

    McEneaney, Victoria

    2010-08-30

    Aldosterone treatment of M1-CCD cells stimulated an increase in epithelial Na(+) channel (ENaC) alpha-subunit expression that was mainly localized to the apical membrane. PKD1-suppressed cells constitutively expressed ENaCalpha at low abundance, with no increase after aldosterone treatment. In the PKD1-suppressed cells, ENaCalpha was mainly localized proximal to the basolateral surface of the epithelium both before and after aldosterone treatment. Apical membrane insertion of ENaCbeta in response to aldosterone treatment was also sensitive to PKD1 suppression as was the aldosterone-induced rise in the amiloride-sensitive, trans-epithelial current (I(TE)). The interaction of the mineralocorticoid receptor (MR) with specific elements in the promoters of aldosterone responsive genes is stabilized by ligand interaction and phosphorylation. PKD1 suppression inhibited aldosterone-induced SGK-1 expression. The nuclear localization of MR was also blocked by PKD1 suppression and MEK antagonism implicating both these kinases in MR nuclear stabilization. PKD1 thus modulates aldosterone-induced ENaC activity through the modulation of sub-cellular trafficking and the stabilization of MR nuclear localization.

  16. Protein kinase D1 modulates aldosterone-induced ENaC activity in a renal cortical collecting duct cell line.

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    McEneaney, Victoria; Dooley, Ruth; Yusef, Yamil R; Keating, Niamh; Quinn, Ursula; Harvey, Brian J; Thomas, Warren

    2010-08-30

    Aldosterone treatment of M1-CCD cells stimulated an increase in epithelial Na(+) channel (ENaC) alpha-subunit expression that was mainly localized to the apical membrane. PKD1-suppressed cells constitutively expressed ENaCalpha at low abundance, with no increase after aldosterone treatment. In the PKD1-suppressed cells, ENaCalpha was mainly localized proximal to the basolateral surface of the epithelium both before and after aldosterone treatment. Apical membrane insertion of ENaCbeta in response to aldosterone treatment was also sensitive to PKD1 suppression as was the aldosterone-induced rise in the amiloride-sensitive, trans-epithelial current (I(TE)). The interaction of the mineralocorticoid receptor (MR) with specific elements in the promoters of aldosterone responsive genes is stabilized by ligand interaction and phosphorylation. PKD1 suppression inhibited aldosterone-induced SGK-1 expression. The nuclear localization of MR was also blocked by PKD1 suppression and MEK antagonism implicating both these kinases in MR nuclear stabilization. PKD1 thus modulates aldosterone-induced ENaC activity through the modulation of sub-cellular trafficking and the stabilization of MR nuclear localization. PMID:20434520

  17. Role of MicroRNAs in Renin-Angiotensin-Aldosterone System-Mediated Cardiovascular Inflammation and Remodeling

    Directory of Open Access Journals (Sweden)

    Maricica Pacurari

    2015-01-01

    Full Text Available MicroRNAs are endogenous regulators of gene expression either by inhibiting translation or protein degradation. Recent studies indicate that microRNAs play a role in cardiovascular disease and renin-angiotensin-aldosterone system- (RAAS- mediated cardiovascular inflammation, either as mediators or being targeted by RAAS pharmacological inhibitors. The exact role(s of microRNAs in RAAS-mediated cardiovascular inflammation and remodeling is/are still in early stage of investigation. However, few microRNAs have been shown to play a role in RAAS signaling, particularly miR-155, miR-146a/b, miR-132/122, and miR-483-3p. Identification of specific microRNAs and their targets and elucidating microRNA-regulated mechanisms associated RAS-mediated cardiovascular inflammation and remodeling might lead to the development of novel pharmacological strategies to target RAAS-mediated vascular pathologies. This paper reviews microRNAs role in inflammatory factors mediating cardiovascular inflammation and RAAS genes and the effect of RAAS pharmacological inhibition on microRNAs and the resolution of RAAS-mediated cardiovascular inflammation and remodeling. Also, this paper discusses the advances on microRNAs-based therapeutic approaches that may be important in targeting RAAS signaling.

  18. Protein kinase D stabilizes aldosterone-induced ERK1/2 MAP kinase activation in M1 renal cortical collecting duct cells to promote cell proliferation.

    LENUS (Irish Health Repository)

    McEneaney, Victoria

    2010-01-01

    Aldosterone elicits transcriptional responses in target tissues and also rapidly stimulates the activation of protein kinase signalling cascades independently of de novo protein synthesis. Here we investigated aldosterone-induced cell proliferation and extra-cellular regulated kinase 1 and 2 (ERK1\\/2) mitogen activated protein (MAP) kinase signalling in the M1 cortical collecting duct cell line (M1-CCD). Aldosterone promoted the proliferative growth of M1-CCD cells, an effect that was protein kinase D1 (PKD1), PKCdelta and ERK1\\/2-dependent. Aldosterone induced the rapid activation of ERK1\\/2 with peaks of activation at 2 and 10 to 30 min after hormone treatment followed by sustained activation lasting beyond 120 min. M1-CCD cells suppressed in PKD1 expression exhibited only the early, transient peaks in ERK1\\/2 activation without the sustained phase. Aldosterone stimulated the physical association of PKD1 with ERK1\\/2 within 2 min of treatment. The mineralocorticoid receptor (MR) antagonist RU28318 inhibited the early and late phases of aldosterone-induced ERK1\\/2 activation, and also aldosterone-induced proliferative cell growth. Aldosterone induced the sub-cellular redistribution of ERK1\\/2 to the nuclei at 2 min and to cytoplasmic sites, proximal to the nuclei after 30 min. This sub-cellular distribution of ERK1\\/2 was inhibited in cells suppressed in the expression of PKD1.

  19. Low plasma aldosterone despite normal plasma renin activity in uncomplicated type 1 diabetes mellitus : effects of RAAS stimulation

    NARCIS (Netherlands)

    Luik, PT; Kerstens, MN; Hoogenberg, K; Navis, GJ; Dullaart, RPF

    2003-01-01

    Background Data on levels and responsiveness of PRA and aldosterone in type 1 diabetes mellitus are conflicting. Earlier studies were not standardized with respect to the type of diabetes mellitus, the presence of diabetic complications or sodium intake. Therefore, we studied plasma renin activity a

  20. Diuretic effect of compounds from Hibiscus sabdariffa by modulation of the aldosterone activity.

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    Jiménez-Ferrer, Enrique; Alarcón-Alonso, Javier; Aguilar-Rojas, Arturo; Zamilpa, Alejandro; Jiménez-Ferrer C, Itzia; Tortoriello, Jaime; Herrera-Ruiz, Maribel

    2012-12-01

    Recent studies of Hibiscus sabdariffa Linn. have demonstrated that it presents diuretic, natriuretic, and potassium sparing effects. However, the mechanism that induces these effects has not yet been elucidated. The aim of this study was to explore the possible mechanism of action for the diuretic effect of Hibiscus sabdariffa extract and its fractions.The aqueous extract from this plant and the fractions obtained with solvents of different polarities were administered to adrenalectomized rats, and the diuretic effect was measured in the presence of deoxycorticosterone acetate (aldosterone analog).The effect on renal filtration was also evaluated in an in situ kidney model, and finally, the effect of diuretic active extracts on gene expression of the alpha subunit from the transporter (αENaC) of renal epithelial cell was quantified. The subsequent results were obtained: The aqueous extract of Hibiscus sabdariffa presented the following chemical composition, 32.4 mg/g delphinidin-3-O-sambubioside, 11.5 mg/g cyanidin-3-O-sambubioside, 11.5 mg/g quercetin, and chlorogenic acid 2.7 mg/g. The concentration of anthocyanins was diminished until disappearance due to decrease of the polarity of the solvents used in the extraction process, in contrast to the flavonoids and chlorogenic acid, which had their concentration increased. The diuretic effect caused by adrenalectomy in rats was reversed by deoxycorticosterone acetate activity. However, the effect of deoxycorticosterone acetate was antagonized by spironolactone, the aqueous extract of Hibiscus sabdariffa, and the acetonitrile : methanol 5 : 5 mixture extract, administered orally. A similar effect was observed on renal filtration obtained from the isolated kidney model.When the gene expression levels of αENaC was measured in adrenalectomized rats, it was observed that spironolactone, the aqueous extract of Hibiscus sabdariffa, the acetonitrile : methanol 5 : 5 mixture, as well as the

  1. Plasma aldosterone concentrations and plasma renin activity in healthy dogs and dogs with hyperadrenocorticism

    NARCIS (Netherlands)

    Javadi, S; Mol, JA; Boer, P; Boer, WH; Runberk, A

    2003-01-01

    The mean (se) basal plasma aldosterone concentrations were significantly lower in 31 dogs with pituitary-dependent hyperadrenocorticism (PDH) (75 [9] pmol/litre) than in 12 healthy dogs (118 [14] pmol/litre), whereas in five dogs with hyperadrenocorticism due to an adrenocortical tumour they were si

  2. Aldosterone as a renal growth factor.

    LENUS (Irish Health Repository)

    Thomas, Warren

    2011-04-05

    Aldosterone regulates blood pressure through its effects on the cardiovascular system and kidney. Aldosterone can also contribute to the development of hypertension that leads to chronic pathologies such as nephropathy and renal fibrosis. Aldosterone directly modulates renal cell proliferation and differentiation as part of normal kidney development. The stimulation of rapidly activated protein kinase cascades is one facet of how aldosterone regulates renal cell growth. These cascades may also contribute to myofibroblastic transformation and cell proliferation observed in pathological conditions of the kidney. Polycystic kidney disease is a genetic disorder that is accelerated by hypertension. EGFR-dependent proliferation of the renal epithelium is a factor in cyst development and trans-activation of EGFR is a key feature in initiating aldosterone-induced signalling cascades. Delineating the components of aldosterone-induced signalling cascades may identify novel therapeutic targets for proliferative diseases of the kidney.

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

    Energy Technology Data Exchange (ETDEWEB)

    Queisser, Nina; Happ, Kathrin; Link, Samuel [Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg (Germany); Jahn, Daniel [Division of Hepatology, Department of Medicine II, University Hospital Würzburg, Würzburg (Germany); Zimnol, Anna [Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg (Germany); Geier, Andreas [Division of Hepatology, Department of Medicine II, University Hospital Würzburg, Würzburg (Germany); Schupp, Nicole, E-mail: schupp@uni-duesseldorf.de [Institute of Pharmacology and Toxicology, University of Würzburg, Würzburg (Germany)

    2014-11-01

    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. 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 receptor and

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

    International Nuclear Information System (INIS)

    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. 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 receptor and

  5. Targeting the aldosterone pathway in cardiovascular disease

    DEFF Research Database (Denmark)

    Gustafsson, Finn; Azizi, Michel; Bauersachs, Johann;

    2012-01-01

    Accumulated evidence has demonstrated that aldosterone is a key player in the pathogenesis of cardiovascular (CV) disease. Multiple clinical trials have documented that intervention in the aldosterone pathway can reduce blood pressure and lower albuminuria and improve outcome in patients with heart...... failure or myocardial infarction. Recent studies have unraveled details about the role of aldosterone at the cellular level in CV disease. The relative importance of glucocorticoids and aldosterone in terms of mineralocorticoid receptor activation is currently being debated. Also, studies are addressing...... which aldosterone modulator to use, which timing of treatment to aim for, and in which population to intervene. This review provides an overview of recent developments in the understanding of the role of aldosterone in CV disease, with particular reference to mechanisms and potential targets...

  6. Inflammatory markers in primary aldosteronism.

    Science.gov (United States)

    Šomlóová, Z; Petrák, O; Rosa, J; Štrauch, B; Indra, T; Zelinka, T; Haluzík, M; Zikán, V; Holaj, R; Widimský, J

    2016-06-20

    Primary aldosteronism (PA) is the most common cause of endocrine hypertension with a high frequency of cardiovascular complications. The unfavorable cardiometabolic profile may be due to aldosterone-mediated activation of inflammatory cells, circulatory cytokines and activation of collagen synthesis in the vessel wall. Aim of our study was to evaluate differences in the levels of hsCRP, IL-6, TNF-alpha and N-terminal propeptide of collagen I (PINP) in patients with PA and essential hypertension (EH) as a control group, and between the subtypes of PA (aldosterone producing adenoma - APA, idiopathic hyperaldosteronism - IHA). We studied 28 patients with PA (IHA - 10 patients, APA - 12 patients, 6 unclassified) and 28 matched patients with EH. There were no differences in the levels of inflammatory markers between the followed groups [EH vs. PA: TNF-alpha (5.09 [3.68-6.32] vs. 4.84 [3.62-6.50] pg/ml), IL-6 (0.94 [0.70-1.13] vs. 0.97 [0.71-1.28] pg/ml), hsCRP (0.53 [0.25-1.54] vs. 0.37 [0.31-0.61] mg/l), leukocytes (6.35+/-1.42 vs. 5.97+/-1.29 10(9) l); APA vs. IHA: TNF-alpha (4.54 [3.62-7.03] vs. 5.19 [4.23-5.27] pg/ml), IL-6 (0.96 [0.63-1.21] vs. 0.90 [0.65-1.06] pg/ml), hsCRP (0.34 [0.29-0.47] vs. 0.75 [0.36-1.11] mg/l), leukocytes (6.37+/-1.41 vs. 5.71+/-1.21 10(9) l)]. Significant differences in the levels of PINP between PA and EH group were observed (35.18 [28.46-41.16] vs. 45.21 [36.95-62.81] microg/l, p

  7. Evaluation of cardiac sympathetic nerve activity and aldosterone suppression in patients with acute decompensated heart failure on treatment containing intravenous atrial natriuretic peptide

    Energy Technology Data Exchange (ETDEWEB)

    Kasama, Shu [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Cardiovascular Hospital of Central Japan (Kitakanto Cardiovascular Hospital), Department of Cardiovascular Medicine, Gunma (Japan); Toyama, Takuji; Kurabayashi, Masahiko [Gunma University Graduate School of Medicine, Department of Medicine and Biological Science (Cardiovascular Medicine), Maebashi, Gunma (Japan); Iwasaki, Toshiya; Sumino, Hiroyuki; Kumakura, Hisao; Minami, Kazutomo; Ichikawa, Shuichi [Cardiovascular Hospital of Central Japan (Kitakanto Cardiovascular Hospital), Department of Cardiovascular Medicine, Gunma (Japan); Matsumoto, Naoya [Nihon University School of Medicine, Department of Cardiology, Tokyo (Japan); Nakata, Tomoaki [Sapporo Medical University School of Medicine, Second (Cardiology) Department of Internal Medicine, Sapporo, Hokkaido (Japan)

    2014-09-15

    Aldosterone prevents the uptake of norepinephrine in the myocardium. Atrial natriuretic peptide (ANP), a circulating hormone of cardiac origin, inhibits aldosterone synthase gene expression in cultured cardiocytes. We evaluated the effects of intravenous ANP on cardiac sympathetic nerve activity (CSNA) and aldosterone suppression in patients with acute decompensated heart failure (ADHF). We studied 182 patients with moderate nonischemic ADHF requiring hospitalization and treated with standard therapy containing intravenous ANP and 10 age-matched normal control subjects. ANP was continuously infused for >96 h. In all subjects, delayed total defect score (TDS), heart to mediastinum ratio, and washout rate were determined by {sup 123}I-metaiodobenzylguanidine (MIBG) scintigraphy. Left ventricular (LV) end-diastolic volume, end-systolic volume, and ejection fraction were determined by echocardiography. All patients with acute heart failure (AHF) were examined once within 3 days and then 4 weeks after admission, while the control subjects were examined only once (when their hemodynamics were normal). Moreover, for 62 AHF patients, plasma aldosterone concentrations were measured at admission and 1 h before stopping ANP infusion. {sup 123}I-MIBG scintigraphic and echocardiographic parameters in normal subjects were more favorable than those in patients with AHF (all p < 0.001). After treatment, all these parameters improved significantly in AHF patients (all p < 0.001). We also found significant correlation between percent changes of TDS and aldosterone concentrations (r = 0.539, p < 0.001) in 62 AHF patients. The CSNA and LV performance were all improved in AHF patients. Furthermore, norepinephrine uptake of myocardium may be ameliorated by suppressing aldosterone production after standard treatment containing intravenous ANP. (orig.)

  8. Evaluation of cardiac sympathetic nerve activity and aldosterone suppression in patients with acute decompensated heart failure on treatment containing intravenous atrial natriuretic peptide

    International Nuclear Information System (INIS)

    Aldosterone prevents the uptake of norepinephrine in the myocardium. Atrial natriuretic peptide (ANP), a circulating hormone of cardiac origin, inhibits aldosterone synthase gene expression in cultured cardiocytes. We evaluated the effects of intravenous ANP on cardiac sympathetic nerve activity (CSNA) and aldosterone suppression in patients with acute decompensated heart failure (ADHF). We studied 182 patients with moderate nonischemic ADHF requiring hospitalization and treated with standard therapy containing intravenous ANP and 10 age-matched normal control subjects. ANP was continuously infused for >96 h. In all subjects, delayed total defect score (TDS), heart to mediastinum ratio, and washout rate were determined by 123I-metaiodobenzylguanidine (MIBG) scintigraphy. Left ventricular (LV) end-diastolic volume, end-systolic volume, and ejection fraction were determined by echocardiography. All patients with acute heart failure (AHF) were examined once within 3 days and then 4 weeks after admission, while the control subjects were examined only once (when their hemodynamics were normal). Moreover, for 62 AHF patients, plasma aldosterone concentrations were measured at admission and 1 h before stopping ANP infusion. 123I-MIBG scintigraphic and echocardiographic parameters in normal subjects were more favorable than those in patients with AHF (all p < 0.001). After treatment, all these parameters improved significantly in AHF patients (all p < 0.001). We also found significant correlation between percent changes of TDS and aldosterone concentrations (r = 0.539, p < 0.001) in 62 AHF patients. The CSNA and LV performance were all improved in AHF patients. Furthermore, norepinephrine uptake of myocardium may be ameliorated by suppressing aldosterone production after standard treatment containing intravenous ANP. (orig.)

  9. Some considerations about evolution of idiopathic primary aldosteronism.

    Science.gov (United States)

    Armanini, D; Fiore, C

    2009-07-01

    The prevalence of primary aldosteronism has increased since many patients who were previously considered as being affected by low renin essential hypertension are actually satisfying the new diagnostic criteria using plasma aldosterone/ plasma renin activity (PRA) ratio. Many of these cases could be classified as subclinical hyperaldosteronism, having normal aldosterone and low PRA, or in alternative the normal range of aldosterone should be revised. Idiopathic hyperaldosteronism can, in many cases, be considered as an evolutive disease: it can be hypothesized that the biochemical picture can be preceded by essential hypertension and that, after several years, primary aldosteronism can evolve back to essential hypertension due to age-related reduced vascular and adrenal sensitivity to angiotensin II. This effect is also evident after longterm treatment with aldosterone receptors blockers and therefore it possible that aldosterone-receptors blockers are able to normalize the sensitivity of glomerulosa to angiotensin II even after long-term withdrawal. The use of aldosterone receptors blockers prevents cardiovascular complications due to local aldosterone effect at the level of endothelium and mononuclear leukocytes; therefore, these drugs should be also considered for therapy of patients with hypertension. It is not excluded that aldosterone receptor blockers could prevent the onset of idiopathic hyperaldosteronism and its complications in patients with hypertension without primary hyperaldosteronism. From all these considerations it follows that the concept of normal range of aldosterone should be revised and the use of aldosterone receptor blockers should be revisited. PMID:19893360

  10. Recent advances in diagnosis and treatment of primary aldosteronism.

    Science.gov (United States)

    Veglio, F; Morello, F; Rabbia, F; Leotta, G; Mulatero, P

    2003-08-01

    Primary aldosteronism is the most common form of secondary hypertension. The use of aldosterone/plasma renin activity ratio (ARR) as a screening test has elevated its prevalence up to 10% of hypertensive patients. Idiopathic bilateral adrenal hyperplasia and aldosterone-producing adrenal adenoma are the leading causes of primary aldosteronism. Most patients with this conditions are normokalemic and clinically undistinguishable from essential hypertensives. However, they suffer from anticipated and more severe target organ damage than other hypertensives. Thus, being primary aldosteronism a common, specifically treatable and sometimes surgically cured form of hypertension, a prompt diagnosis is necessary and cannot be overlooked. The measurement of ambulatory ARR represents the screening test and should be performed in the majority of hypertensive patients. ARR higher than a set cutoff suggests the need of a confirmatory test for primary aldosteronism, such as intravenous saline load or fludrocortisone suppression test. If inability to suppress aldosterone is demonstrated, the disease is confirmed. The subtype evaluation is based on adrenal imaging (CT scan) and selective adrenal venous sampling. The latter is the gold standard for the diagnosis of a lateralized aldosterone secretion, as typically observed in aldosterone-producing adenomas. Microadenomas are frequently overlooked by adrenal image. If lateralization is confirmed, unilateral adrenalectomy is the reasonable therapeutic option, leading to a significant reduction of blood pressure, if not normotension. If bilateral aldosterone excess is demonstrated, an aldosterone receptor antagonist should be administered. This article reviews and discusses the new data about prevalence, diagnosis and treatment of primary aldosteronism. PMID:14605590

  11. Aortic Cell Apoptosis in Rat Primary Aldosteronism Model

    Institute of Scientific and Technical Information of China (English)

    闫永吉; 欧阳金芝; 王超; 吴准; 马鑫; 李宏召; 徐华; 胡争; 李俊; 王保军; 史涛坪; 龚道静; 倪栋; 张旭

    2010-01-01

    This study aimed to determine whether aldosterone could induce vascular cell apoptosis in vivo.Thirty-two male rats were randomly divided into 4 groups:vehicle(control),aldosterone,aldosterone plus eplerenone or hydralazine.They were then implanted with an osmotic mini-pump that infused either aldosterone or the vehicle.Systolic blood pressure(SBP) was measured weekly by the tail-cuff method.After 8 weeks,plasma aldosterone concentration(PAC) and renin activity(PRA) were determined by radioimmunoassay.Aorti...

  12. Aldosterone and Renin Test

    Science.gov (United States)

    ... are used to treat high blood pressure. Stress, exercise, and pregnancy can also affect the test results. Coffee, tea or cola can affect the 24-hour urine sample test. Your doctor will tell you if you should change the amount of ... routine before aldosterone testing. Licorice may mimic aldosterone ...

  13. Moderate inappropriately high aldosterone/NaCl constellation in mice: cardiovascular effects and the role of cardiovascular epidermal growth factor receptor.

    Science.gov (United States)

    Schreier, Barbara; Rabe, Sindy; Winter, Sabrina; Ruhs, Stefanie; Mildenberger, Sigrid; Schneider, Bettina; Sibilia, Maria; Gotthardt, Michael; Kempe, Sabine; Mäder, Karsten; Grossmann, Claudia; Gekle, Michael

    2014-01-01

    Non-physiological activation of the mineralocorticoid receptor (MR), e.g. by aldosterone under conditions of high salt intake, contributes to the pathogenesis of cardiovascular diseases, although beneficial effects of aldosterone also have been described. The epidermal growth factor receptor (EGFR) contributes to cardiovascular alterations and mediates part of the MR effects. Recently, we showed that EGFR is required for physiological homeostasis and function of heart and arteries in adult animals. We hypothesize that moderate high aldosterone/NaCl, at normal blood pressure, affects the cardiovascular system depending on cardiovascular EGFR. Therefore we performed an experimental series in male and female animals each, using a recently established mouse model with EGFR knockout in vascular smooth muscle cells and cardiomyocytes and determined the effects of a mild-high aldosterone-to-NaCl constellation on a.o. marker gene expression, heart size, systolic blood pressure, impulse conduction and heart rate. Our data show that (i) cardiac tissue of male but not of female mice is sensitive to mild aldosterone/NaCl treatment, (ii) EGFR knockout induces stronger cardiac disturbances in male as compared to female animals and (iii) mild aldosterone/NaCl treatment requires the EGFR in order to disturb cardiac tissue homeostasis whereas beneficial effects of aldosterone seem to be independent of EGFR. PMID:25503263

  14. Uremic toxins induce kidney fibrosis by activating intrarenal renin-angiotensin-aldosterone system associated epithelial-to-mesenchymal transition.

    Directory of Open Access Journals (Sweden)

    Chiao-Yin Sun

    Full Text Available BACKGROUND: Uremic toxins are considered to have a determinant pathological role in the progression of chronic kidney disease. The aim of this study was to define the putative pathological roles of the renal renin-angiotensin-aldosterone system (RAAS and renal tubular epithelial-to-mesenchymal transition (EMT in kidney fibrosis induced by (indoxyl sulfate IS and (p-cresol sulfate PCS. METHODS: Mouse proximal renal tubular cells (PKSV-PRs treated with IS or PCS were used. Half-nephrectomized B-6 mice were treated with IS or PCS for 4 weeks. In the losartan treatment study, the study animal was administrated with IS+losartan or PCS+losartan for 4 weeks. RESULTS: IS and PCS significantly activated the intrarenal RAAS by increasing renin, angiotensinogen, and angiotensin 1 (AT1 receptor expression, and decreasing AT2 receptor expression in vitro and in vivo. IS and PCS significantly increased transforming growth factor-β1 (TGF-β1 expression and activated the TGF-β pathway by increasing Smad2/Smad2-P, Smad3/Smad3-P, and Smad4 expression. The expression of the EMT-associated transcription factor Snail was increased by IS and PCS treatment. IS and PCS induced the phenotype of EMT-like transition in renal tubules by increasing the expression of fibronectin and α-smooth muscle actin and decreasing the expression of E-cadherin. Losartan significantly attenuated the expression of TGF-β1 and Snail, and decreased kidney fibrosis induced by IS and PCS in vivo. CONCLUSION: Activating the renal RAAS/TGF-β pathway has an important pathological role in chronic kidney injury caused by IS and PCS. IS and PCS may increase Snail expression and induce EMT-like transition.

  15. Mechanisms underlying rapid aldosterone effects in the kidney.

    LENUS (Irish Health Repository)

    Thomas, Warren

    2011-03-17

    The steroid hormone aldosterone is a key regulator of electrolyte transport in the kidney and contributes to both homeostatic whole-body electrolyte balance and the development of renal and cardiovascular pathologies. Aldosterone exerts its action principally through the mineralocorticoid receptor (MR), which acts as a ligand-dependent transcription factor in target tissues. Aldosterone also stimulates the activation of protein kinases and secondary messenger signaling cascades that act independently on specific molecular targets in the cell membrane and also modulate the transcriptional action of aldosterone through MR. This review describes current knowledge regarding the mechanisms and targets of rapid aldosterone action in the nephron and how aldosterone integrates these responses into the regulation of renal physiology.

  16. Mechanisms underlying rapid aldosterone effects in the kidney.

    LENUS (Irish Health Repository)

    Thomas, Warren

    2012-02-01

    The steroid hormone aldosterone is a key regulator of electrolyte transport in the kidney and contributes to both homeostatic whole-body electrolyte balance and the development of renal and cardiovascular pathologies. Aldosterone exerts its action principally through the mineralocorticoid receptor (MR), which acts as a ligand-dependent transcription factor in target tissues. Aldosterone also stimulates the activation of protein kinases and secondary messenger signaling cascades that act independently on specific molecular targets in the cell membrane and also modulate the transcriptional action of aldosterone through MR. This review describes current knowledge regarding the mechanisms and targets of rapid aldosterone action in the nephron and how aldosterone integrates these responses into the regulation of renal physiology.

  17. Aldosterone blood test

    Science.gov (United States)

    ... Pregnancy High- or low-sodium diet Strenuous exercise Stress How the Test will Feel When the needle is inserted to ... pressure. Aldosterone increases the reabsorption of sodium and water and the release of potassium in the kidneys. ...

  18. Role of mineralocorticoid receptor and renin-angiotensin-aldosterone system in adipocyte dysfunction and obesity.

    Science.gov (United States)

    Feraco, Alessandra; Armani, Andrea; Mammi, Caterina; Fabbri, Andrea; Rosano, Giuseppe M C; Caprio, Massimiliano

    2013-09-01

    The mineralocorticoid receptor (MR) classically mediates aldosterone effects on salt homeostasis and blood pressure regulation in epithelial target tissues. In recent years, functional MRs have been identified in non classical targets of aldosterone actions, in particular in adipose tissue, where they mediate the effects of aldosterone and glucocorticoids in the control of adipogenesis, adipose expansion and its pro-inflammatory capacity. In this context, inappropriate MR activation has been demonstrated to be a causal factor in several pathologic conditions such as vascular inflammation, endothelial dysfunction, insulin resistance and obesity. The aim of this review is to summarize the latest developments in this rapidly developing field, and will focus on the role of MR and renin-angiotensin-aldosterone system (RAAS) as potential leading characters in the early steps of adipocyte dysfunction and obesity. Indeed modulation of MR activity in adipose tissue has promise as a novel therapeutic approach to treat obesity and its related metabolic complications. This article is part of a Special Issue entitled 'CSR 2013'. PMID:23454117

  19. The regulation of cell growth and survival by aldosterone.

    LENUS (Irish Health Repository)

    Dooley, Ruth

    2012-02-01

    The steroid hormone aldosterone is synthesized from cholesterol, mainly in the zona glomerulosa of the adrenal cortex. Aldosterone exerts its effects in the epithelial tissues of the kidney and colon and in non-epithelial tissues such as the brain and cardiovasculature. The genomic response to aldosterone involves dimerization of the mineralocorticoid receptor (MR), dissociation of heat shock proteins from MR, translocation of the aldosterone-MR complex to the nucleus and the concomitant regulation of gene expression. Rapid responses to aldosterone occur within seconds to minutes, do not involve transcription or translation and can modulate directly or indirectly the later genomic responses. Aside from the well-known effects of aldosterone on the regulation of sodium and water homeostasis, aldosterone can also produce deleterious structural changes in tissues by inducing hypertrophy and the dysregulation of proliferation and apoptosis, leading to fibrosis and tissue remodelling. Here we discuss the involvement of aldosterone-mediated rapid signalling cascades in the development of disease states such as chronic kidney disease and heart failure, and the antagonists that can inhibit these pathophysiological responses.

  20. The regulation of cell growth and survival by aldosterone.

    LENUS (Irish Health Repository)

    Dooley, Ruth

    2011-01-01

    The steroid hormone aldosterone is synthesized from cholesterol, mainly in the zona glomerulosa of the adrenal cortex. Aldosterone exerts its effects in the epithelial tissues of the kidney and colon and in non-epithelial tissues such as the brain and cardiovasculature. The genomic response to aldosterone involves dimerization of the mineralocorticoid receptor (MR), dissociation of heat shock proteins from MR, translocation of the aldosterone-MR complex to the nucleus and the concomitant regulation of gene expression. Rapid responses to aldosterone occur within seconds to minutes, do not involve transcription or translation and can modulate directly or indirectly the later genomic responses. Aside from the well-known effects of aldosterone on the regulation of sodium and water homeostasis, aldosterone can also produce deleterious structural changes in tissues by inducing hypertrophy and the dysregulation of proliferation and apoptosis, leading to fibrosis and tissue remodelling. Here we discuss the involvement of aldosterone-mediated rapid signalling cascades in the development of disease states such as chronic kidney disease and heart failure, and the antagonists that can inhibit these pathophysiological responses.

  1. A case of posterior reversible encephalopathy syndrome in the setting of post-partum preeclampsia with suppressed plasma aldosterone levels and plasma renin activity

    Directory of Open Access Journals (Sweden)

    Aurelio Negro

    2013-12-01

    Full Text Available Posterior reversible encephalopathy syndrome (PRES is characterized by headache, altered mental status, visual loss, and seizures. PRES is associated with neuroradiological findings: white matter abnormalities, predominantly in the parieto-occipital regions of the brain. PRES has been described in association with hypertensive encephalopathy, eclampsia, renal failure, or following immunosuppressive or anticancer therapy. We report a case of PRES in a severe preeclampsia occurring in the late postpartum period, with suppressed plasma aldosterone levels and plasma renin activity. These laboratory abnormalities may be due to an apparent mineralocorticoid excess syndrome.

  2. Increased plasma aldosterone during atrial fibrillation declines following cardioversion

    DEFF Research Database (Denmark)

    Soeby-Land, C; Dixen, U; Therkelsen, S K;

    2011-01-01

    The renin-angiotensin-aldosterone system (RAAS) may be activated during atrial fibrillation (AF); our aim was to evaluate the level of aldosterone in patients with either permanent AF, persistent AF scheduled for cardioversion or patients in sinus rhythm (SR). We hypothesized that an increased...

  3. Local aldosterone system mediated "hyperglycaemic memory" in human mesangial cells%局部醛固酮系统介导高糖致人系膜细胞损伤记忆效应

    Institute of Scientific and Technical Information of China (English)

    杜超; 熊勤攀; 周波; 苏红

    2012-01-01

    Objective To investigate the effect of hyperglycaemic memory on the local aldosterone system, reactive oxygen species (ROS) and expression of oncofetal fibronectin (oncofetal FN) mRNA in human mesangial cells (HMCs) ,and to further understand the role of local aldosterone system in the process. Methods In this study HMCs were divided into the following groups:normal glucose group (NG, 5 mmol/L D-glucose for 2 days),high glucose group (HG, 25 mmol/L D-glucose for 2 days), memory group (M, 25 mmol/L D-glucose for 2 days-* 5 mmol/L D-glucose for 4 days) , memory + eplerenone group (MY,25 mmol/L D-glucose for 2 days^-5 mmol/L D-glucose+10 //mol/L eplerenone for 4 days), normal glucose + eplerenone group (NY,5 mmol/L D-glucose for 2 days —- 5 mmol/L D-glucose+10 (imol/L eplerenone for 4 days),and persistent normal glucose group (SN, 5 mmol/L D-glucose for 6 days). ROS levels were tested by fluorescence microscope and fluorescence microplate reader. Aldosterone synthase (CYP11B2) protein expression was detected by Western blotting analysis. The mRNA expressions of llphydroxysteroid dehydrogenase type 2,CYP11B2 and oncofetal FN were detected by RT-PCR. The expression and translocation of mineralocorticoid receptor (MR) was observed by laser scanning confocal microscope (LSCM). Aldosterone level in cell culture supernatant was detected by radioimmunoassay. Results (DCYP11B2 mRNA and protein expression in group HG and in group M were all significantly increased, being 3. 45 , 2. 09 and 3. 14, 2. 06 folds of those in group NG, respectively (all F<0. 05). The aldosterone levels in HMCs culture supernatant were significantly increased in group HG and group M, being 2. 01 and 1. 81 folds of that in group NG. respectively (Pactivated and translocated from the cytosol to the nucleus in group HG and group M. Quantitative analysis showed that the ratios of cytosol/ nucleus fluorescence intensity in group HG and group M were decreased by 30% and 21% compared with

  4. Regulation of Adrenal Aldosterone Production by Serine Protease Prostasin

    Directory of Open Access Journals (Sweden)

    Takehiro Ko

    2010-01-01

    Full Text Available A serine protease prostasin has been demonstrated to have a pivotal role in the activation of the epithelial sodium channel. Systemic administration of adenovirus carrying human prostasin gene in rats resulted in an increase in plasma prostasin and aldosterone levels. However, the mechanism by which the elevation of prostasin levels in the systemic circulation stimulated the plasma aldosterone levels remains unknown. Therefore, we examined if prostasin increases the aldosterone synthesis in a human adrenocortical cell line (H295R cells. Luciferase assay using CYP11B2 promoter revealed that prostasin significantly increased the transcriptional activity of CYP11B2. Prostasin significantly increased both CYP11B2 mRNA expression and aldosterone production in a dose-dependent manner. Surprisingly, treatment with camostat mesilate, a potent prostasin inhibitor, had no effect on the aldosterone synthesis by prostasin and also a protease-dead mutant of prostasin significantly stimulated the aldosterone production. A T-type/L-type calcium channel blocker and a protein kinase C (PKC inhibitor significantly reduced the aldosterone synthesis by prostasin. Our findings suggest a stimulatory effect of prostasin on the aldosterone synthesis by adrenal gland through the nonproteolytic action and indicate a new role of prostasin in the systemic circulation.

  5. Renin and aldosterone at high altitude in man.

    Science.gov (United States)

    Keynes, R J; Smith, G W; Slater, J D; Brown, M M; Brown, S E; Payne, N N; Jowett, T P; Monge, C C

    1982-01-01

    Measurements have been made of hormonal changes relevant to salt and water balance during prolonged exposure to hypoxia to improve our understanding of the syndrome of acute mountain sickness. We have attempted to delineate the detailed inter-relationships between the renin-aldosterone and the vasopressin systems by a metabolically controlled study, involving an orthostatic stress (45 degrees head-up tilt) and an injection of a standard dose of ACTH to test adrenal responsiveness. Three Caucasian medical students underwent a 7-day equilibration at 150 m (Lima, Peru), followed by a 6-day sojourn at 4350 m (Cerro de Pasco, Peru) and a final 7 days at 150 m. Measurements were made of sodium and potassium balance, body weight and the 24-h renal excretion of vasopressin, cortisol and aldosterone 18-glucuronide. These variables showed little change, except for that of aldosterone 18-glucuronide, which fell sharply at altitude and rebounded even more sharply on return to sea level. At altitude, basal plasma levels of renin activity and aldosterone fell, and the response to orthostasis was attenuated, but the fall of plasma renin activity, as compared to plasma aldosterone, was delayed; on return to sea level this dissociation was exacerbated with the return of normal renin responsiveness lagging behind that of aldosterone. We suggest that unknown factors which dissociate the orthodox renin-aldosterone relationship, other than the activity of the angiotensin I-converting enzyme, are operative on exposure to hypoxia. PMID:7057120

  6. A particular phenotype in a girl with aldosterone synthase deficiency.

    Science.gov (United States)

    Williams, Tracy A; Mulatero, Paolo; Bosio, Maurizio; Lewicka, Sabina; Palermo, Mario; Veglio, Franco; Armanini, Decio

    2004-07-01

    Aldosterone synthase deficiency (ASD) usually presents in infancy as a life-threatening electrolyte imbalance. A 4-wk-old child of unrelated parents was examined for failure to thrive and salt-wasting. Notable laboratory findings were hyperkalemia, high plasma renin, and low-normal aldosterone levels. Urinary metabolite ratios of corticosterone/18-hydroxycorticosterone and 18-hydroxycorticosterone/aldosterone were intermediate between ASD type I and type II. Sequence analysis of CYP11B2, the gene encoding aldosterone synthase (P450c11AS), revealed that the patient was a compound heterozygote carrying a previously described mutation located in exon 4 causing a premature stop codon (E255X) and a further, novel mutation in exon 5 that also causes a premature stop codon (Q272X). The patient's unaffected father was a heterozygous carrier of the E255X mutation, whereas the unaffected mother was a heterozygous carrier of the Q272X mutation. Therefore, the patient's CYP11B2 encodes two truncated forms of aldosterone synthase predicted to be inactive because they lack critical active site residues as well as the heme-binding site. This case of ASD is of particular interest because despite the apparent lack of aldosterone synthase activity, the patient displays low-normal aldosterone levels, thus raising the question of its source. PMID:15240589

  7. Aldosterone Induces Tissue Inhibitor of Metalloproteinases-1 Expression and Further Contributes to Collagen Accumulation: From Clinical to Bench Studies.

    Science.gov (United States)

    Hung, Chi-Sheng; Chou, Chia-Hung; Liao, Che-Wei; Lin, Yen-Tin; Wu, Xue-Ming; Chang, Yi-Yao; Chen, Ying-Hsien; Wu, Vin-Cent; Su, Ming-Jai; Ho, Yi-Lwun; Chen, Ming-Fong; Wu, Kwan-Dun; Lin, Yen-Hung

    2016-06-01

    Aldosterone induces myocardial fibrosis. Tissue inhibitor of metalloproteinases-1 (TIMP-1) is a key factor of myocardial fibrosis. This study tested the hypothesis that aldosterone induces TIMP-1 expression and contributes to the fibrotic process. We prospectively enrolled 54 patients with primary aldosteronism, and measured plasma TIMP-1 and echocardiographic parameters. In the cell study, we investigated the possible molecular mechanism by which aldosterone induces TIMP-1 secretion and the effects on collagen accumulation. In the animal study, we measured serum TIMP-1 levels, cardiac TIMP-1 levels, and cardiac structure in an aldosterone infusion mouse model using implantation of aldosterone pellets. In patients with primary aldosteronism, plasma TIMP-1 was correlated with 24-hour urinary aldosterone, left ventricular mass, and impairment of left ventricular diastolic function. In human cardiac fibroblasts, TIMP-1 protein and mRNA expressions were significantly increased by aldosterone through the glucocorticoid receptor/PI3K/Akt/nuclear factor-κB pathway. TIMP-1 small-interfering RNA significantly reduced aldosterone-induced collagen accumulation, and aldosterone did not alter the levels of collagen1a1 or matrix metalloproteinase-1 mRNA. The aldosterone-induced TIMP-1 expression was inversely related to matrix metalloproteinase-1 activity. Furthermore, in the animal model, the serum and cardiac levels of TIMP-1 were significantly elevated in the mice that received aldosterone infusion. This elevation was blocked by RU-486 but not by eplerenone, suggesting that the effect was through glucocorticoid receptors. In a long-term aldosterone infusion model, serum TIMP-1 was associated with serum aldosterone level, cardiac structure, and fibrosis. In conclusion, aldosterone induced TIMP-1 expression in vivo and in vitro. This increased TIMP-1 expression resulted in enhanced collagen accumulation via the suppression of matrix metalloproteinase-1 activity. PMID:27113051

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

    Science.gov (United States)

    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.

  9. Aldosterone-induced signalling and cation transport in the distal nephron.

    LENUS (Irish Health Repository)

    Thomas, Warren

    2008-10-01

    Aldosterone is an important regulator of Na(+) and K(+) transport in the distal nephron modulating the surface expression of transporters through the action of the mineralocorticoid receptor as a ligand-dependent transcription factor. Aldosterone stimulates the rapid activation of protein kinase-based signalling cascades that modulate the genomic effects of the hormone. Evidence is accumulating about the multi-factorial regulation of the epithelial sodium channel (ENaC) by aldosterone. Recent published data suggests that the activation of a novel PKC\\/PKD signalling pathway through the c-Src-dependent trans-activation of epidermal growth factor receptor contributes to early ENaC trafficking in response to aldosterone.

  10. Early aldosterone-induced gene product regulates the epithelial sodium channel by deubiquitylation.

    Science.gov (United States)

    Fakitsas, Panagiotis; Adam, Gabriele; Daidié, Dorothée; van Bemmelen, Miguel X; Fouladkou, Fatemeh; Patrignani, Andrea; Wagner, Ulrich; Warth, Richard; Camargo, Simone M R; Staub, Olivier; Verrey, François

    2007-04-01

    The mineralocorticoid hormone aldosterone controls sodium reabsorption and BP largely by regulating the cell-surface expression and function of the epithelial sodium channel (ENaC) in target kidney tubules. Part of the stimulatory effect of aldosterone on ENaC is mediated by the induction of serum- and glucocorticoid-regulated kinase 1 (Sgk1), a kinase that interferes with the ubiquitylation of ENaC by ubiquitin-protein ligase Nedd4-2. In vivo early aldosterone-regulated mRNA now has been identified in microselected mouse distal nephron by microarray. From 22 mRNA that displayed a two-fold or more change, 13 were downregulated and nine were upregulated. Besides Sgk1, the induced mRNA include Grem2 (protein related to DAN and cerebrus [PRDC]), activating transcription factor 3, cAMP responsive element modulator, and the ubiquitin-specific protease Usp2-45. The induction of this last enzyme isoform was verified in mouse distal nephron tubule at the protein level. With the use of Hek293 cells, Xenopus oocytes, and mpkCCD(c14) cells as expression systems, it was shown that Usp2-45 deubiquitylates ENaC and stimulates ENaC-mediated sodium transport, an effect that is not additive to that of Sgk1. A deubiquitylating enzyme that targets ENaC in vitro and thus may play a role in sodium transport regulation was identified within a series of new in vivo early aldosterone-regulated gene products. PMID:17344426

  11. Recurrence of adrenal aldosterone-producing adenoma

    OpenAIRE

    Calvo-Romero, J. M.; Ramos-Salado, J. L.

    2000-01-01

    Conn's syndrome (adrenal aldosterone-producing adenoma) and bilateral adrenal hyperplasia are the most common causes of primary aldosteronism. The treatment of choice for patients with aldosterone-producing adenoma is unilateral total adrenalectomy. Recurrence after adequate surgery is exceptional. We present a patient with recurrence of an aldosterone-producing adenoma in the right adrenal gland 9 years after adenomectomy of a aldosterone-producing adenoma in the same adrenal gland. We concl...

  12. Somatic and germline CACNA1D calcium channel mutations in aldosterone-producing adenomas and primary aldosteronism

    Science.gov (United States)

    Scholl, Ute I.; Goh, Gerald; Stölting, Gabriel; de Oliveira, Regina Campos; Choi, Murim; Overton, John D.; Fonseca, Annabelle L.; Korah, Reju; Starker, Lee F.; Kunstman, John W.; Prasad, Manju L.; Hartung, Erum A.; Mauras, Nelly; Benson, Matthew R.; Brady, Tammy; Shapiro, Jay R.; Loring, Erin; Nelson-Williams, Carol; Libutti, Steven K.; Mane, Shrikant; Hellman, Per; Westin, Gunnar; Åkerström, Göran; Björklund, Peyman; Carling, Tobias; Fahlke, Christoph; Hidalgo, Patricia; Lifton, Richard P.

    2013-01-01

    Adrenal aldosterone-producing adenomas (APAs) constitutively produce the salt-retaining hormone aldosterone and are a common cause of severe hypertension. Recurrent mutations in the potassium channel KCNJ5 that result in cell depolarization and Ca2+ influx cause ~40% of these tumors1. We found five somatic mutations (four altering glycine 403, one altering isoleucine 770) in CACNA1D, encoding a voltage-gated calcium channel, among 43 non-KCNJ5-mutant APAs. These mutations lie in S6 segments that line the channel pore. Both result in channel activation at less depolarized potentials, and glycine 403 mutations also impair channel inactivation. These effects are inferred to cause increased Ca2+ influx, the sufficient stimulus for aldosterone production and cell proliferation in adrenal glomerulosa2. Remarkably, we identified de novo mutations at the identical positions in two children with a previously undescribed syndrome featuring primary aldosteronism and neuromuscular abnormalities. These findings implicate gain of function Ca2+ channel mutations in aldosterone-producing adenomas and primary aldosteronism. PMID:23913001

  13. Epicardial Fat Thickness and Primary Aldosteronism.

    Science.gov (United States)

    Iacobellis, G; Petramala, L; Marinelli, C; Calvieri, C; Zinnamosca, L; Concistrè, A; Iannucci, G; De Toma, G; Letizia, C

    2016-04-01

    Primary aldosteronism (PA) is associated with increased cardiovascular risk and left ventricle (LV) changes. Given its peculiar biomolecular and anatomic properties, excessive epicardial fat, the heart-specific visceral fat depot, can affect LV morphology. Whether epicardial fat can be associated with aldosterone and LV mass (LVM) in patients with PA is unknown. We performed ultrasound measurement of the epicardial fat thickness (EAT) in 79 consecutive newly diagnosed patients with PA, 59 affected by bilateral adrenal hyperplasia (IHA), 20 aldosterone-producing adenoma (APA), and 30 patients with essential hypertension (low renin hypertension) (EH). The 3 groups did not differ by age, sex distribution, body mass index (BMI), waist circumference (WC), or blood pressure values. EAT showed a trend of increase in both APA and IHA groups when compared to patients with EH (8.3±1.8 vs. 7.9±1.3 vs. 7.8±2 mm, respectively). EAT was significantly correlated with indexed LVM in the IHA group (r=0.35, p<005), better than BMI or WC were. Interestingly, EAT was highly associated with plasma aldosterone concentrations (PAC) and PAC/plasma renin activity (PRA) (PAC/PRA) in the APA group (p=0.58, p=0.37, p<0.01, for both), whereas BMI and WC were not. EAT was also correlated with PRA in the IHA group (p=-0.28, p<0.05). Our study indicates a novel and interesting interaction of EAT with PA, independent of obesity, abdominal fat and blood pressure control. EAT can locally affect LVM, at least in patients with IHA. Further studies in larger population will be required to confirm these findings. PMID:26983926

  14. Histamine-dependent prolongation by aldosterone of vasoconstriction in isolated small mesenteric arteries of the mouse

    DEFF Research Database (Denmark)

    Schjerning, Jeppe; Uhrenholt, Torben R; Svenningsen, Per; Vanhoutte, Paul M; Skott, Ole; Jensen, Boye L; Hansen, Pernille B L

    2013-01-01

    In arterioles, aldosterone counteracts the rapid dilatation ("recovery") following depolarization-induced contraction. The hypothesis was tested that this effect of aldosterone depends on COX-derived products and/or NOS inhibition. Recovery of the response to high K(+) was observed in mesenteric...... by aldosterone. Actinomycin-D abolished the effect of aldosterone indicating a genomic effect. The effect was blocked by indomethacin and by the COX-1 inhibitor valeryl salicylate but not by NS-398 (10(-6) mol/L) or the TP-receptor antagonist S18886 (10(-7) mol/L). The effect of aldosterone on...... recovery in arteries from wild type mice and the SNP-mediated dilatation in arteries from eNOS(-/-) mice was inhibited by the histamine H2 receptor antagonist cimetidine. RT-PCR showed expression of mast cell markers in mouse mesenteric arteries. The adventitia displayed granular cells positive for...

  15. Primary aldosteronism and pregnancy.

    Science.gov (United States)

    Landau, Ester; Amar, Laurence

    2016-06-01

    Hypertension (HT) is a complication of 8% of all pregnancies and 10% of HT cases are due to primary aldosteronism (PA). There is very little data on PA and pregnancy. Given the changes in the renin angiotensin system during pregnancy, the diagnosis of PA is difficult to establish during gestation. It may be suspected in hypertensive patients with hypokalemia. A comprehensive literature review identified reports covering 40 pregnancies in patients suffering from PA. Analysis of these cases shows them to be high-risk pregnancies leading to maternal and fetal complications. Pregnancy must be programmed, and if the patient has a unilateral form of PA, adrenalectomy should be performed prior to conception. It is customary to stop spironolactone prior to conception and introduce antihypertensive drugs that present no risk of teratogenicity. When conventional antihypertensive drugs used during pregnancy fail to control high blood pressure, diuretics, including potassium-sparing diuretics may be prescribed. Adrenalectomy can be considered during the second trimester of pregnancy exclusively in cases of refractory hypertension. A European retrospective study is currently underway to collect a larger number of cases. PMID:27156905

  16. The Role of Aldosterone in Obesity-Related Hypertension.

    Science.gov (United States)

    Kawarazaki, Wakako; Fujita, Toshiro

    2016-04-01

    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

  17. Non-genomic actions of aldosterone: From receptors and signals to membrane targets.

    LENUS (Irish Health Repository)

    Dooley, Ruth

    2011-07-26

    In tissues which express the mineralocorticoid receptor (MR), aldosterone modulates the expression of membrane targets such as the subunits of the epithelial Na(+) channel, in combination with important signalling intermediates such as serum and glucocorticoid-regulated kinase-1. In addition, the rapid \\'non-genomic\\' activation of protein kinases and secondary messenger signalling cascades has also been detected in aldosterone-sensitive tissues of the nephron, distal colon and cardiovascular system. These rapid actions are variously described as being coupled to MR or to an as yet unidentified, membrane-associated aldosterone receptor. The rapidly activated signalling cascades add a level of fine-tuning to the activity of aldosterone-responsive membrane transporters and also modulate the aldosterone-induced changes in gene expression through receptor and transcription factor phosphorylation.

  18. Non-genomic actions of aldosterone: From receptors and signals to membrane targets.

    LENUS (Irish Health Repository)

    2012-02-01

    In tissues which express the mineralocorticoid receptor (MR), aldosterone modulates the expression of membrane targets such as the subunits of the epithelial Na(+) channel, in combination with important signalling intermediates such as serum and glucocorticoid-regulated kinase-1. In addition, the rapid \\'non-genomic\\' activation of protein kinases and secondary messenger signalling cascades has also been detected in aldosterone-sensitive tissues of the nephron, distal colon and cardiovascular system. These rapid actions are variously described as being coupled to MR or to an as yet unidentified, membrane-associated aldosterone receptor. The rapidly activated signalling cascades add a level of fine-tuning to the activity of aldosterone-responsive membrane transporters and also modulate the aldosterone-induced changes in gene expression through receptor and transcription factor phosphorylation.

  19. Early aldosterone-induced gene product regulates the epithelial sodium channel by deubiquitylation

    OpenAIRE

    Fakitsas, P; Adam, G.; Daidié, D; van Bemmelen, M X; Fouladkou, F; Patrignani, A; U. Wagner; Warth, R.; Camargo, S M R; Staub, O.; Verrey, F

    2007-01-01

    The mineralocorticoid hormone aldosterone controls sodium reabsorption and BP largely by regulating the cell-surface expression and function of the epithelial sodium channel (ENaC) in target kidney tubules. Part of the stimulatory effect of aldosterone on ENaC is mediated by the induction of serum- and glucocorticoid-regulated kinase 1 (Sgk1), a kinase that interferes with the ubiquitylation of ENaC by ubiquitin-protein ligase Nedd4-2. In vivo early aldosterone-regulated mRNA now has been ide...

  20. Aldosterone-induced ENaC and basal Na+/K+-ATPase trafficking via protein kinase D1-phosphatidylinositol 4-kinaseIIIβ trans Golgi signalling in M1 cortical collecting duct cells.

    Science.gov (United States)

    Dooley, Ruth; Angibaud, Emmanuelle; Yusef, Yamil R; Thomas, Warren; Harvey, Brian J

    2013-06-15

    Aldosterone regulates Na(+) transport in the distal nephron through multiple mechanisms that include the transcriptional control of epithelial sodium channel (ENaC) and Na(+)/K(+)-ATPase subunits. Aldosterone also induces the rapid phosphorylation of Protein Kinase D1 (PKD1). PKD isoforms regulate protein trafficking, by the control of vesicle fission from the trans Golgi network (TGN) through activation of phosphatidylinositol 4-kinaseIIIβ (PI4KIIIβ). We report rapid ENaCγ translocation to the plasma membrane after 30 min aldosterone treatment in polarized M1 cortical collecting duct cells, which was significantly impaired in PKD1 shRNA-mediated knockdown cells. In PKD1-deficient cells, the ouabain-sensitive current was significantly reduced and Na(+)/K(+)-ATPase α and β subunits showed aberrant localization. PKD1 and PI4KIIIβ localize to the TGN, and aldosterone induced an interaction between PKD1 and PI4KIIIβ following aldosterone treatment. This study reveals a novel mechanism for rapid regulation of ENaC and the Na(+)/K(+)-ATPase, via directed trafficking through PKD1-PI4KIIIβ signalling at the level of the TGN. PMID:23541637

  1. Recent Developments in Primary Aldosteronism.

    Science.gov (United States)

    Asbach, E; Williams, T A; Reincke, M

    2016-06-01

    Primary aldosteronism (PA) is the most frequent endocrine cause of secondary arterial hypertension. Sporadic forms of PA caused mainly by an aldosterone producing adenoma (APA) or idiopathic adrenal hyperplasia (IAH) predominate; in contrast, familial forms (familial hyperaldosteronism types I, II and III) affect only a minor proportion of PA patients. Patient based registries and biobanks, international networks and next generation sequencing technologies have emerged over recent years. Somatic hot-spot mutations in the potassium channel GIRK4 (encoded by KCNJ5), in ATPases and a L-type voltage-gated calcium-channel correlate with the autonomous aldosterone production in approximately half of all APAs. The recently discovered form FH III is caused by different germline KCNJ5 mutations with variable clinical presentations and severity. Autoantibodies to the angiotensin II Type 1 receptor have been identified in patients with PA and possibly play a pathophysiological role in the development of PA. Adrenal vein sampling (AVS) represents the gold standard in differentiating unilateral and bilateral forms of PA. Recent consensus papers have tried to implement current guidelines in order to standardise the technique of AVS. New techniques like segmental AVS might allow a finer mapping of the aldosterone production within the adrenal gland. The measurement of the steroids 18-hydroxycortisol and 18-oxocortisol by liquid chromatography tandem mass spectrometry has been shown to be useful to distinguish between unilateral and bilateral forms of PA. PMID:27219889

  2. Mineralocorticoid receptor is involved in the aldosterone pathway in human red blood cells.

    Science.gov (United States)

    Bordin, Luciana; Saccardi, Carlo; Donà, Gabriella; Sabbadin, Chiara; Andrisani, Alessandra; Ambrosini, Guido; Plebani, Mario; Brunati, Anna Maria; Ragazzi, Eugenio; Gizzo, Salvatore; Armanini, Decio

    2016-01-01

    We have recently demonstrated that excessive aldosterone (Aldo) secretion in primary aldosteronism (PA) is associated with red blood cells (RBC) senescence. These alterations were prevented/inhibited by cortisol (Cort) or canrenone (Can) raising the hypothesis that Aldo effects in RBC may be mediated by mineralocorticoid receptor (MR), though to date MR has never been demonstrated in human RBC. The aim of this multicenter comparative study was to investigate whether Aldo effects were mediated by MR in these a-nucleated cells. We included 12 healthy controls (HC) and 22 patients with PA. MR presence and activation were evaluated in RBC cytosol by glycerol gradient sedimentation, Western blotting, immuno-precipitation and radioimmunoassay. We demonstrated that RBC contained cytosolic MR, aggregated with HSP90 and other proteins to form multiprotein complex. Aldo induced MR to release from the complex and to form MR dimers which were quickly proteolyzed. Cort induced MR release but not dimers formation while Can was not able to induce MR release. In addition, RBC cytosol from PA patients contained significantly higher amounts of both MR fragments (p<0.0001) and Aldo (p<0.0001) concentrations. In conclusion, in RBC a genomic-like Aldo pathway is proposed involving MR activation, dimerization and proteolysis, but lacking nuclear transcription. In addition, dimers proteolysis may ensure a sort of Aldo scavenging from circulation by entrapping Aldo in MR fragments. PMID:27158328

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

    Science.gov (United States)

    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 inAgtr1a(-/-)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 inAgtr1a(-/-)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 inAgtr1a(-/-)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 andAgtr1a(-/-)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 channelKcnmb1, which may enhance myogenic tone and together with sodium retention, exacerbate BP responses to aldosterone/salt inAgtr1a(-/-)mice. We conclude that although aldosterone activation of mineralocorticoid receptors raises BP more inAgtr1a(-/-)mice, AGTR1a is required for mineralocorticoid receptor stimulation to induce vascular remodeling and inflammation and endothelial dysfunction. PMID:27045029

  4. Does aldosterone play a significant role for regulation of vascular tone?

    DEFF Research Database (Denmark)

    Lyngsø, Kristina Sanne; Assersen, Kasper Bostlund; Dalgaard, Emil Geertsen;

    2016-01-01

    formation and vasoconstrictor effects through endothelial contracting cyclooxygenase derived-factors and a changed calcium handling. The response to aldosterone can change within the same blood vessels depending on the exposure time and status of the endothelium. Chronic responses involve changed levels of...... reactive oxygen radicals, endothelia Na-influx and smooth muscle calcium channel expression and perivascular cells, e.g. mast cells, also participate. Moreover, the vascular effect of aldosterone depends on the status of the endothelium which is likely cause of the very different responses to aldosterone...... cells through stimulus-secretion coupling involving depolarization, opening of L- and T-type calcium channels and aldosterone synthase activation. Local formation and release in peripheral tissues such as perivascular fat is recognized. Where does aldosterone affect the vasculature? Mineralocorticoid...

  5. Rapid effects of aldosterone in primary cultures of cardiomyocytes - do they suggest the existence of a membrane-bound receptor?

    Science.gov (United States)

    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. PMID:27305962

  6. Estímulos para la liberación de aldosterona durante una actividad física intensa y de larga duración Stimuli for aldosterone secretion during an intense, long duration physucak activity

    Directory of Open Access Journals (Sweden)

    Hilda Norha Jaramillo Londoño

    2001-01-01

    Full Text Available Objetivo: establecer los posibles factores causales de la secreción de aldosterona durante una actividad física intensa y de larga duración, bajo condiciones ambientales neutras, en nueve corredores de fondo. Materiales y métodos: después de 10 minutos de calentamiento, en banda rodante con una pendiente del 1% y al 55% de la capacidad física de trabajo máxima (PWCmax, siguieron 90 minutos de carrera, al 80%; finalmente, 90 minutos de recuperación pasiva. No se hizo reposición hídrica durante DH (deshidratado; durante RH (rehidratado se repuso el 51% del peso corporal perdido en DH. Resultados: en DH hubo pérdida de peso corporal y reducción porcentual del volumen plasmático (%VP. Se observaron hiperosmolaridad, hipernatremia, hipercaliemia, hiperaldosteronemia, pero no hiperreninemia. Al hacer corrección por hemoconcentración y calcular el porcentaje de cambio de las variables en estudio, sólo se observaron hipercaliemia e hiperaldosteronemia. En RH la pérdida de peso corporal fue menor, pero la reducción %VP fue similar; se evitaron la hiperosmolaridad y la hipernatremia, pero no la hipercaliemia durante el ejercicio ni la hiperaldosteronemia durante todo el procedimiento, un comportamiento similar al observado al hacer corrección por hemoconcentración. Conclusiones: Durante la realización de una actividad física intensa la concentración plasmática de aldosterona presentó un incremento proporcional a la duración del ejercicio e independiente de la reducción porcentual del volumen plasmático. La hipersecreción de aldosterona es, al parecer, multicausal y el potasio es uno de los factores determinantes. Objective: To establish the possible causal factors of aldosterone secretion during an intense, long duration physical activity, under neutral environmental conditions in nine long-distance runners. Methods: After a 10-minute warm-up period on a treadmill, 1% grade and at 55% of PWCmax, followed by 90 minutes test in

  7. Mediatized Extreme Right Activism and Discourse

    DEFF Research Database (Denmark)

    Peters, Rikke Alberg

    2015-01-01

    and mediatized activism. In order to analyse of the protest form, the visual aesthetics and the discourse of ‘The Immortals’, the paper mobilises two concepts from media and communication studies: mediation and mediatization. It will be argued that that the current transformation of the extreme right: that is...

  8. Microalbuminuria and hypertension in pregnancy: role of aldosterone and inflammation.

    Science.gov (United States)

    Armanini, Decio; Ambrosini, Guido; Sabbadin, Chiara; Donà, Gabriella; Clari, Giulio; Bordin, Luciana

    2013-09-01

    Women with a history of hypertension in pregnancy are at increased risk of microalbuminuria later in life. Microalbuminuria is a marker of kidney dysfunction frequently related to an inflammatory event. Pregnancy is a dynamic process characterized by immune tolerance, angiogenesis, and hormonal regulation. Menstruation and pregnancy are associated with a physiological inflammation, which is altered in preeclampsia and probably in other hypertensive situations of pregnancy. An imbalance between pro-oxidant factors and the ability to scavenge these factors produces oxidative stress, which has been evaluated in many cells, but leukocytes are the main source of inflammatory cytokines and experimental and clinical evidence support a possible role of aldosterone as a mediator of placental and renal damage mediated by growth factors, reactive oxygen species, and cytokines. Angiotensin-converting enzyme inhibitors and aldosterone receptor blockers are frequently effective in reducing the risk of progression of cardiovascular and renal disease. PMID:24034651

  9. The difficulties in differential diagnosis of primary aldosteronism subtypes in women with strokes at a young age

    International Nuclear Information System (INIS)

    In patients with primary aldosteronism (PA), it is fundamental to distinguish between subtypes that benefit from different treatment. The authors describe difficulties in differential diagnosis in a case of 46 year old women with PA and two strokes in the past. Based on high plasma and urine aldosterone concentration, low plasma renin activity (PRA), very high aldosterone/PRA ratio and unilateral macroadenoma detected in computed tomography, aldosterone producing adenoma was diagnosed and the patient was performed unilateral adrenalectomy. Despite the surgical treatment the patient still presented with clinical and biochemical PA symptoms. Moreover, histological examination suggested adrenal hyperplasia, and laboratory tests were typical for glucocorticoid-remediable aldosteronism. Unfortunately, we didn't find a chimeric CYP 11β1/CYP 11βb2 gene. Finally, bilateral adrenal hyperplasia was diagnosed and medical treatment with aldosterone antagonist was initiated. (authors)

  10. Does Aldosterone Play a Significant Role for Regulation of Vascular Tone?

    Science.gov (United States)

    Lyngsø, Kristina S; Assersen, Kasper; Dalgaard, Emil G; Skott, Ole; Jensen, Boye L; Hansen, Pernille B L

    2016-07-01

    Besides the well-known renal effects of aldosterone, the hormone is now known to have direct vascular effects. Clinical observations underline substantial adverse effects of aldosterone on cardiovascular function. The source of systemic circulating aldosterone is the adrenal gland zona glomerulosa cells through stimulus-secretion coupling involving depolarization, opening of L- and T-type calcium channels and aldosterone synthase activation. Local formation and release in peripheral tissues such as perivascular fat is recognized. Where does aldosterone affect the vasculature? Mineralocorticoid receptors (MRs) are present in endothelial and vascular smooth muscle cells, and MR-independent pathways are also involved. The vascular effects of aldosterone are complex, both concentration and temporal and spatial aspects are relevant. The acute response includes vasodilation through endothelial nitric oxide formation and vasoconstrictor effects through endothelial-contracting cyclooxygenase-derived factors and a changed calcium handling. The response to aldosterone can change within the same blood vessels depending on the exposure time and status of the endothelium. Chronic responses involve changed levels of reactive oxygen radicals, endothelial Na-influx and smooth muscle calcium channel expression. Furthermore, perivascular cells for example mast cells have also been suggested to participate in the chronic response. Moreover, the vascular effect of aldosterone depends on the status of the endothelium which is likely the cause of the very different responses to aldosterone and MR treatment observed in human studies going from increased to decreased flow depending on whether the patient had prior cardiovascular disease with endothelial dysfunction or not. A preponderance of constrictor versus dilator responses to aldosterone could therefore be involved in the detrimental vascular actions of the hormone in the setting of endothelial dysfunction and contribute to explain

  11. Extraordinarily high aldosterone, 901.0 ng/dL, in a patient with primary aldosteronism: an insight into the underlying mechanism.

    Science.gov (United States)

    Okubo, Yosuke; Sato, Yuka; Nakasone, Yasuto; Shirotori, Katsuko; Oguchi, Kazuhiro; Matsushita, Tsuyoshi; Nishikawa, Tetsuo; Yamazaki, Yuto; Sasano, Hironobu; Komatsu, Mitsuhisa; Yamauchi, Keishi; Aizawa, Toru

    2016-02-29

    A 43-yr-old hypertensive male was admitted due to hypokalemia (1.8 mEq/L) and renal dysfunction (eGFR, 20.0 mL/min/1.73 m(2)). His plasma aldosterone was 901.0 ng/dL, plasma renin activity 5.7 ng/mL/hr, and aldosterone/renin activity ratio 158. Angiotensin II (AII) was 0.7 pg/mL, ACTH mass spectrometry analysis showed that aldosterone (104 times the control) as well as its precursors were significantly elevated in the patient's plasma. A left adrenal (4-cm-diameter) tumor with (131)I-Adosterol® uptake was found and removed. Four days later, plasma aldosterone and renin activity had dropped to 7.73 ng/dL and 1.6 ng/mL/hr, respectively. However, they rose to 24.0 ng/dL and 10.9 ng/mL/hr, respectively, by Day 102. Nevertheless, magnetic resonance angiography found no evidence of a renovascular lesion. The tumor was a benign adrenocortical adenoma composed predominantly of clear cells positive for 17α-hydroxylase, [hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerases], and aldosterone synthase. A quantitative real-time polymerase chain reaction analysis of the tumor cells revealed that expression of the gene encoding aldosterone synthase was 85 times the control level. In addition, the tumor cells harbored G151R mutation of the inward rectifying potassium channel subfamily j, member 5 gene. The striking overexpression of aldosterone synthase by the tumor cells was considered the primary mechanism for the extravagant overproduction of aldosterone in this case. This overexpression may have resulted from integration of signals from AII and forced membrane depolarization due to the potassium channel mutation. PMID:26549209

  12. 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.

    Science.gov (United States)

    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

  13. Idiopathic primary hyperaldosteronism: normalization of plasma aldosterone after one month withdrawal of long-term therapy with aldosterone-receptor antagonist potassium canrenoate.

    Science.gov (United States)

    Armanini, D; Scaroni, C; Mattarello, M J; Fiore, C; Albiger, N; Sartorato, P

    2005-03-01

    We have re-evaluated 15 patients with idiopathic primary aldosteronism one month after withdrawal of therapy with aldosterone-receptor antagonist potassium canrenoate. Therapy had lasted for 3 to 24 yr. Median blood pressure (BP) in the sitting position at the time of diagnosis was 160/100 (ranges 150-200/95-110 mmHg); while 1 month after withdrawal of therapy median BP was 145/90 (ranges 125-160/80-100 mmHg). One month after withdrawal, the ratio aldosterone (ng/dl)/plasma renin activity (ng/ml/h) in the upright position was increased only in 3 cases (median 18, range 6.1-125). We found a significant inverse correlation between the upright aldosterone/plasma renin activity (aldo/PRA) ratio, 1 month after withdrawal, and the number of years of therapy with potassium canrenoate. We conclude that long-term therapy with the aldosterone-receptor blocker, potassium canrenoate, can normalize the aldo/PRA ratio in many cases of idiopathic primary hyperaldosteronism after one-month withdrawal of the drug. These data are consistent with possible regression of idiopathic primary hyperaldosteronism after long-term therapy with potassium canrenoate, or in alternative to a persistent effect of potassium canrenoate, on aldosterone synthesis. PMID:15952408

  14. Reversible heart rhythm complexity impairment in patients with primary aldosteronism

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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 (bothP<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. PMID:26975710

  16. Familial varieties of primary aldosteronism.

    Science.gov (United States)

    Stowasser, M; Gunasekera, T G; Gordon, R D

    2001-12-01

    1. Improved approaches to screening and diagnosis have revealed primary aldosteronism (PAL) to be much more common than previously thought, with most patients normokalaemic. The spectrum of this disorder has been further broadened by the study of familial varieties. 2. Familial hyperaldosteronism type I (FH-I) is a glucocorticoid-remediable form of PAL caused by the inheritance of an adrenocorticotrophic hormone (ACTH)- regulated, hybrid CYP11B1/CYP11B2 gene. Diagnosis has been greatly facilitated by the advent of genetic testing. The severity of hypertension varies widely in FH-I, even among members of the same family, and has demonstrated relationships with gender, degree of biochemical disturbance and hybrid gene crossover point position. Hormone "day curve" studies show that the hybrid gene dominates over wild-type CYP11B2 in terms of aldosterone regulation. This may be due, in part, to a defect in wild-type CYP11B2-induced aldosterone production. Control of hypertension in FH-I requires only partial suppression of ACTH and much smaller glucocorticoid doses than previously recommended. 3. Familial hyperaldosteronism type II (FH-II) is not glucocorticoid remediable and is not associated with the hybrid gene mutation. Familial hyperaldosteronism type II is clinically, biochemically and morphologically indistinguishable from apparently non-familial PAL. Linkage studies in one informative family did not show segregation of FH-II with the CYP11B2, AT1 or MEN1 genes, but a genome-wide search has revealed linkage with a locus in chromosome 7. As has already occurred in FH-I, elucidation of causative mutations is likely to facilitate earlier detection of PAL. PMID:11903322

  17. Evidence for Concerted Effects of Aldosterone On a Target Sodium-transporting Epithelium

    OpenAIRE

    BEAUWENS, R; Crabbé, J.

    1983-01-01

    The sodium-transporting activity of toad skin is stimulated in vitro with aldosterone in the absence of energy-providing substrate; it can be stimulated further upon addition of glucose after prolonged (overnight) incubation. The magnifying effect exerted by glucose in these conditions could be blocked by inhibitors of ribonucleic acid and protein biosynthesis. In addition, exposure to cycloheximide prevented the increase in thermodynamic affinity resulting from aldosterone treatment. A synth...

  18. Zero gravity and cardiovascular homeostasis. The relationship between endogenous hyperprolactinemia and plasma aldosterone. Summary report, 1 February 1977--31 January 1978

    International Nuclear Information System (INIS)

    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 μg of thyrotropin-releasing-hormone. Prolactin increased at 15 min following injection of 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

  19. Zero gravity and cardiovascular homeostasis. The relationship between endogenous hyperprolactinemia and plasma aldosterone. Summary report, 1 February 1977--31 January 1978

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-01-31

    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 ..mu..g of thyrotropin-releasing-hormone. Prolactin increased at 15 min following injection of 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.

  20. Energy National Mediator activity report 2009

    International Nuclear Information System (INIS)

    After some data illustrating the activity of the Energy National Mediator in 2009, and an interview of a representative of this institution who comments its practice, this report proposes the opinions of the different involved actors (communities, consumer associations, providers, and so on) about the mediator. It puts the adopted strategy in perspective from the past year to the coming one. It describes the missions: information, advice, protection. It reports actions, recommendations and facts for 2009 in terms of consumer information, group mediation, poverty management, samples of analysed disputes. It presents the social organisation and gives a financial assessment of the institution

  1. Aldosterone and type 2 diabetes mellitus.

    Science.gov (United States)

    Zavatta, Guido; Casadio, Elena; Rinaldi, Eleonora; Pagotto, Uberto; Pasquali, Renato; Vicennati, Valentina

    2016-04-01

    Primary hyperaldosteronism (PA) has recently been demonstrated to be strictly associated to metabolic syndrome as compared with essential hypertension (EH). Besides, the characteristics of metabolic syndrome are different in PA compared to EH, as high fasting glucose is more frequent in the former condition. The adverse effect of excess aldosterone on insulin metabolic signaling has generated increasing interest in the role of hyperaldosteronism in the pathogenesis of insulin resistance and resistant hypertension. Moreover, aldosterone receptor antagonist therapy in diabetic and cardiopathic patients improved coronary flow. The aim of this review is to present recent knowledge about the relationship between aldosterone, insulin resistance and diabetes. PMID:26876814

  2. Acute mechanical sensitization of peripheral nociceptors by aldosterone through non-genomic activation of membrane bound mineralocorticoid receptors in naive rats.

    Science.gov (United States)

    Shaqura, Mohammed; Li, Xiongjuan; Al-Madol, Mohammed A; Tafelski, Sascha; Beyer-Koczorek, Antje; Mousa, Shaaban A; Schäfer, Michael

    2016-08-01

    Recently, there is increasing interest in the role of peripheral mineralocorticoid receptors (MR) to modulate pain, but their localization in neurons and glia of the periphery and their distinct involvement in pain control remains elusive. In naive Wistar rats our double immunofluorescence confocal microscopy of the spinal cord, dorsal root ganglia, sciatic nerve and innervated skin revealed that MR predominantly colocalized with calcitonin-gene-related peptide (CGRP)- and trkA-immunoreactive (IR) nociceptive neurons and only marginally with myelinated trkB-IR mechanoreceptive and trkC-IR proprioreceptive neurons underscoring a pivotal role for MR in the modulation of pain. MR could not be detected in Schwann cells, satellite cells, and astrocytes and only scarcely in spinal microglia cells excluding a relevant functional role of glia-derived MR at least in naïve rats. Intrathecal (i.t.) and intraplantar (i.pl.) application of increasing doses of the MR selective agonist aldosterone acutely increased nociceptive behavior which was reversible by a MR selective antagonist and most likely due to non-genomic effects. This was further substantiated by the first identification of membrane bound MR specific binding sites in sensory neurons of dorsal root ganglia and spinal cord. Therefore, a crucial role of MR on nociceptive neurons but not on glia cells and their impact on nociceptive behavior most likely due to immediate non-genomic effects has to be considered under normal but more so under pathological conditions in future studies. PMID:27016023

  3. Regulation of Na+ channels in frog lung epithelium: a target tissue for aldosterone action.

    Science.gov (United States)

    Fischer, H; Clauss, W

    1990-04-01

    Sodium transport across isolated lung tissue of the frog Xenopus laevis was measured in Ussing chambers under voltage-clamp conditions. Perfusing the lungs with NaCl-Ringer's solutions on both sides, a basal distinct amiloride-blockable Na+ current was present. Incubating the lungs with 1 mumol/l aldosterone from the pleural side raised the short circuit current after a 1-h latent period. Maximal values were reached after 4-5 h of aldosterone treatment, at which time the transepithelial Na+ current was more than doubled compared to the control. The stimulatory effect was totally inhibited when the aldosterone treatment was preceded by incubation of the lung tissues with spironolactone in 2000-fold excess. In the presence of amiloride (0.5-8 mumol/l) in the alveolar compartment, a Lorentzian noise component appeared in the power spectrum of the fluctuations in the short circuit current. This enabled the calculation of single Na+ channel current and Na+ channel density under both experimental conditions. Aldosterone stimulation did not change single Na+ channel current. On the other hand, the number of conducting Na+ channels increased in parallel with the transepithelial Na+ transport. This suggests that the alveolar epithelium may be a physiological target tissue for aldosterone. Since fluid absorption in the lung is secondary to active Na+ transport, aldosterone may be a potent regulator for maintaining the relatively fluid-free state of the lumen of the lung in some cases of fluid accumulation. PMID:2162035

  4. Direct microassay for aldosterone in plasma extracts

    International Nuclear Information System (INIS)

    We previously described an RIA for aldosterone based on highly specific antibodies elicited with aldosterone-3,20 dioxime bovine γ-globulin (Poulsen, K., J. Sancho, and E. Haber, Clin Immunol Immunopathol 2: 373, 1974). We now report the development of higher affinity antibodies of similar specificity that allow the direct measurement of normal aldosterone concentrations in extracts of 100 μl plasma. The detection limit at +-2 SD of mean zero value was 0.2 to 0.3 pg. The assay was validated by (1) zero values in adrenalectomized plasma, (2) parallel displacement plots of aldosterone standards and plasma extracts, (3) 97.7 +- 2.5% recovery of added tracer, (4) a correlation coefficient of 0.992 and a slope of 1.08 in a plot of added vs. recovered unlabeled aldosterone, (5) 10.2% interassay variation and 5.6% intrassay variation, and (6) failure of high concentrations of a variety of steroids added to plasma to perturb the measured aldosterone concentration. The simplicity of the assay results in a high degree of productivity, in that 195 plasma samples may be processed in duplicate, in addition to standard curves, in a single working day

  5. Localization of aldosterone-producing tumours in primary aldosteronism by adrenal and renal vein catheterization

    DEFF Research Database (Denmark)

    Lund, J O; Nielsen, M D; Giese, Jacob; Gammelgaard, P A; Hasner, E; Hesse, B; Tønnesen, K H

    1980-01-01

    Regional venous plasma aldosterone concentrations were determined and assessed against concurrent arterial levels in 16 patients with primary aldosteronism. The results obtained by sampling from the left adrenal vein or the left renal vein allowed correct side prediction of the presupposed adenom...

  6. Aldosterone and the conquest of land.

    Science.gov (United States)

    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

  7. Aldosterone metabolism in the isolated perfused liver of female and male rats

    International Nuclear Information System (INIS)

    A sex-dependent metabolism of aldosterone has been reported in intact rats. To further characterize the hepatic elimination of aldosterone and its sex dependence, the metabolism of d-[4-14C]aldosterone was studied in isolated perfused liver from male and female Wistar rats, from male rats castrated 3 weeks before experiments, and from younger male rats (same body weight as the female rats). The livers were perfused at a constant flow rate in a recirculating mode with a hemoglobin-free medium containing aldosterone at initially 1 nM. Perfusate aldosterone was measured by a specific RIA. Total 4-14C radio-activity in perfusate and bile was determined. The perfusate [4-14C]aldosterone radiometabolite concentration was calculated. The radiometabolite pattern in additional experiments was studied by HPLC. The male rats exhibited 10% higher systolic blood pressure (P less than 0.05) and 51% higher fasting values of plasma aldosterone (P less than 0.05) compared to those in the female rats. In female rats the hepatic clearance rate of aldosterone per 100 g BW was 72% higher than that in male rats (11.2 +/- 2.7 to 6.5 +/- 1.8 ml/min: P less than 0.01), and that expressed per g liver wet wt was 75% higher (3.5 +/- 1.0 to 2.0 +/- 0.7 ml/min; P less than 0.01). When female rats were compared to younger male rats with the same body weight, 33% higher hepatic aldosterone clearance rates were still found in female rats (21.0 +/- 5.4 to 15.8 +/- 3.2 ml/min; P less than 0.05), and 51% higher values when expressed per g liver wet wt (3.5 +/- 1.0 to 2.3 +/- 0.5 ml/min; P less than 0.01). No difference in the aldosterone clearance rate was observed in castrated male rats compared to that in noncastrated male rats. 4-14C-Labeled radiometabolite levels accumulated similarly in the perfusate of livers of both sexes

  8. Blood pressure in patients with primary aldosteronism is influenced by bradykinin B(2) receptor and alpha-adducin gene polymorphisms.

    Science.gov (United States)

    Mulatero, Paolo; Williams, Tracy A; Milan, Alberto; Paglieri, Cristina; Rabbia, Franco; Fallo, Francesco; Veglio, Franco

    2002-07-01

    Primary aldosteronism (PA) is the most common cause of endocrine hypertension. PA is most frequently presented as moderate to severe hypertension, but the clinical and biochemical features vary widely. The aim of our study was to identify genetic variants that influence the phenotype of patients with PA. We hypothesized that genetic variants potentially affecting aldosterone production (aldosterone synthase, CYP11B2), renal proximal tubule reabsorption (alpha-adducin), or the mechanisms of counterbalance leading to vasodilatation and sodium excretion (bradykinin B(2)-receptor, B(2)R) could influence the clinical and biochemical characteristics of patients with PA. We studied three polymorphisms of these genes (C-344T of CYP11B2, G460W of alpha-adducin, and C-58T of B(2)R) in 167 primary aldosteronism patients (56 with aldosterone-producing adenoma and 111 with idiopathic hyperaldosteronism). B(2)R and alpha-adducin genotypes were strong independent predictors of both systolic and diastolic blood pressure levels; plasma renin activity and aldosterone also play a marginal role on BP levels. Body mass index, age, sex, and CYP11B2 genotype displayed no significant effect on the clinical parameters of our population. In particular, alpha-adducin and B(2)R polymorphisms accounted for 13.2% and 11.0% of the systolic and diastolic blood pressure variance, respectively. These data suggest that genetic variants of alpha-adducin and the bradykinin B(2)-R influence the blood pressure levels in patients with primary aldosteronism. PMID:12107246

  9. Aldosterone and the mineralocorticoid receptor in the cerebral circulation and stroke

    Directory of Open Access Journals (Sweden)

    Dinh Quynh N

    2012-10-01

    Full Text Available Abstract Ischemic stroke is a leading cause of morbidity and mortality worldwide. Elevated plasma aldosterone levels are an independent cardiovascular risk factor and are thought to contribute to hypertension, a major risk factor for stroke. Evidence from both experimental and human studies supports a role for aldosterone and/or the mineralocorticoid receptor (MR in contributing to detrimental effects in the cerebral vasculature and to the incidence and outcome of ischemic stroke. This article reviews the evidence, including the protective effects of MR antagonism. Specifically, the effects of aldosterone and/or MR activation on cerebral vascular structure and on immune cells will be reviewed. The existing evidence suggests that aldosterone and the MR contribute to cerebral vascular pathology and to the incidence and outcome of stroke. We suggest that further research into the signaling mechanisms underlying the effects of aldosterone and MR activation in the brain and its vasculature, especially with regard to cell-specific actions, will provide important insight into causes and potential treatments for cerebrovascular disease and stroke.

  10. Computer tomographic localisation in primary aldosteronism

    International Nuclear Information System (INIS)

    13 patients with verified primary aldosteronism (unilateral adrenal adenoma = 10, bilateral idiopathic hyperplasia = 3) underwent examination by CT and 131J-cholesterol-scintigraphy. CT-scan can be successfully employed for localization of unilateral adenoma exceeding 10 mm in diameter. Small lesions and hyperplasia are rare CT-findings. The value of 131J-cholesterol-scintigraphy for differentiation of the two main subgroups of primary aldosteronism - adenoma and hyperplasia - is limited. In our experience both noninvasive methods are helpful to avoid misleading interpretation. In controversial cases bilateral adrenal venous blood sampling by catheterization is mandatory. (orig.)

  11. Activism and the Online Mediation Opportunity Structure

    DEFF Research Database (Denmark)

    Uldam, Julie

    2013-01-01

    The annual United Nations (UN) Framework Convention on Climate Change conferences provides a transnational mediation opportunity structure for activist networks to contest policies that favor market-based models for solving the climate crisis. Online technologies, including commercial social media...... climate change activism. This impedes possibilities for using online media to protest at the radical end of the climate justice movement spectrum. This article explores this interrelationship between activist demands and (online) modes of action through a focus on the mobilization efforts of London...

  12. Discovery and in Vivo Evaluation of Potent Dual CYP11B2 (Aldosterone Synthase) and CYP11B1 Inhibitors.

    Science.gov (United States)

    Meredith, Erik L; Ksander, Gary; Monovich, Lauren G; Papillon, Julien P N; Liu, Qian; Miranda, Karl; Morris, Patrick; Rao, Chang; Burgis, Robin; Capparelli, Michael; Hu, Qi-Ying; Singh, Alok; Rigel, Dean F; Jeng, Arco Y; Beil, Michael; Fu, Fumin; Hu, Chii-Whei; LaSala, Daniel

    2013-12-12

    Aldosterone is a key signaling component of the renin-angiotensin-aldosterone system and as such has been shown to contribute to cardiovascular pathology such as hypertension and heart failure. Aldosterone synthase (CYP11B2) is responsible for the final three steps of aldosterone synthesis and thus is a viable therapeutic target. A series of imidazole derived inhibitors, including clinical candidate 7n, have been identified through design and structure-activity relationship studies both in vitro and in vivo. Compound 7n was also found to be a potent inhibitor of 11β-hydroxylase (CYP11B1), which is responsible for cortisol production. Inhibition of CYP11B1 is being evaluated in the clinic for potential treatment of hypercortisol diseases such as Cushing's syndrome. PMID:24900631

  13. Statins attenuate polymethylmethacrylate-mediated monocyte activation.

    LENUS (Irish Health Repository)

    Laing, Alan J

    2012-02-03

    BACKGROUND: Periprosthetic osteolysis precipitates aseptic loosening of components, increases the risk of periprosthetic fracture and, through massive bone loss, complicates revision surgery and ultimately is the primary cause for failure of joint arthroplasty. The anti-inflammatory properties of HMG-CoA reductase inhibitors belonging to the statin family are well recognized. We investigated a possible role for status in initiating the first stage of the osteolytic cycle, namely monocytic activation. METHODS: We used an in vitro model of the human monocyte\\/macrophage inflammatory response to poly-methylmethacrylate (PMMA) particles after pretreat-ing cells with cerivastatin, a potent member of the statin family. Cell activation based upon production of TNF-alpha and MCP-1 cytokines was analyzed and the intracellular Raf-MEK-ERK signal transduction pathway was evaluated using western blot analysis, to identify its role in cell activation and in any cerivastatin effects observed. RESULTS: We found that pretreatment with cerivastatin significantly abrogates the production of inflammatory cytokines TNF-alpha and MCP-1 by human monocytes in response to polymethylmethacrylate particle activation. This inflammatory activation and attenuation appear to be mediated through the intracellular Raf-MEK-ERK pathway. INTERPRETATION: We propose that by intervening at the upstream activation stage, subsequent osteoclast activation and osteolysis can be suppressed. We believe that the anti-inflammatory properties of statins may potentially play a prophylactic role in the setting of aseptic loosening, and in so doing increase implant longevity.

  14. An additional child case of an aldosterone-producing adenoma with an atypical presentation of peripheral paralysis due to hypokalemia.

    Science.gov (United States)

    Dinleyici, E C; Dogruel, N; Acikalin, M F; Tokar, B; Oztelcan, B; Ilhan, H

    2007-11-01

    Aldosterone-producing adenoma, which is characterized by hypertension, hypokalemia, and elevated aldosterone levels with suppressed plasma renin activity, is a rare condition during childhood and is also potentially curable. To the best of our knowledge, nearly 25 cases of childhood aldosterone-secreting adenoma have been reported in the literature to date. Here we describe a 13-yr-old girl with primary hyperaldosteronism secondary to aldosterone-secreting adenoma. The patient was admitted to our hospital with the neuromuscular complaints of muscle weakness and inability to walk due to hypokalemia. She had been misdiagnosed as having hypokalemic periodic paralysis 2 months before admission and her symptoms had radically improved with potassium supplementation. However, her blood pressure levels had increased and her symptoms reappeared 2 days prior to being observed during hospitalization in our institution. Laboratory examinations revealed hypokalemia (2.1 mEq/l), and increased serum aldosterone levels with suppressed plasma renin activity. Abdominal ultrasonography and abdominal magnetic resonance imaging revealed left adrenal mass. Laparoscopic adrenalectomy was performed and histopathological examinations showed benign adrenal adenoma. Serum aldosterone levels and blood pressure levels returned to normal after surgical intervention. This case demonstrates the importance of a systemic evaluation including blood pressure monitorization of children with hypokalemia as intermittent hypertension episodes may be seen; cases without hypertension may be misdiagnosed as rheumatological or neurological disorders such as hypokalemic periodic paralysis, as in our case. PMID:18075291

  15. Evaluating Active U: an internet-mediated physical activity program

    Directory of Open Access Journals (Sweden)

    Goodrich David E

    2009-09-01

    Full Text Available Abstract Background Engaging in regular physical activity can be challenging, particularly during the winter months. To promote physical activity at the University of Michigan during the winter months, an eight-week Internet-mediated program (Active U was developed providing participants with an online physical activity log, goal setting, motivational emails, and optional team participation and competition. Methods This study is a program evaluation of Active U. Approximately 47,000 faculty, staff, and graduate students were invited to participate in the online Active U intervention in the winter of 2007. Participants were assigned a physical activity goal and were asked to record each physical activity episode into the activity log for eight weeks. Statistics for program reach, effectiveness, adoption, and implementation were calculated using the Re-Aim framework. Multilevel regression analyses were used to assess the decline in rates of data entry and goal attainment during the program, to assess the likelihood of joining a team by demographic characteristics, to test the association between various predictors and the number of weeks an individual met his or her goal, and to analyze server load. Results Overall, 7,483 individuals registered with the Active U website (≈16% of eligible, and 79% participated in the program by logging valid data at least once. Staff members, older participants, and those with a BMI P Conclusion Internet-mediated physical activity interventions that focus on physical activity logging and goal setting while incorporating team competition may help a significant percentage of the target population maintain their physical activity during the winter months.

  16. Studies on the subcommissural organ area in the rat: the effects aldosterone infused into the central nervous system

    International Nuclear Information System (INIS)

    D-aldosterone (5 ng/μl/hr) was infused for six days into the area of the subcommissural organ (SCO) of conscious rats to test the hypothesis that the SCO and the adrenal zona glomerulosa are related functionally in a negative feedback manner. Aldosterone increased urinary sodium loss and the sodium/potassium ratio. These effects still occurred when cannulae were displaced caudally up to 1 mm from the targeted SCO area. Aldosterone decreased the cross-sectional area of the adrenal medulla without affecting chromaffin cell density. Adrenal content of corticosterone was increased. These effects were highly dependent upon proper cannula placement and were not observed when the tip of the cannula was not in contact with the cerebrospinal fluid of the pineal recess over the rostral two-thirds of the SCO. Aldosterone infused intracerebroventricularly (ivt) into a lateral ventricle had no effect on sodium excretion, adrenal corticosterone concentration or adrenal morphology. After the infusion of radiolabelled aldosterone into the SCO area, the majority of the radioactivity was restricted to an area about 1-2 mm in diameter from the SCO. Iron-dextran injected intraperiotoneally did not accumulate in the SCO; therefore, the blood-brain barrier is intact. It is concluded that the effects of aldosterone were dependent upon the area of the brain in which it was infused. Aldosterone increased sodium excretion by an action in the SCO and/or adjacent structures. A relationship between mineralocorticoids and the adrenal modulla mediated by the SCO is also postulated. With regard to the blood-brain and brain-CSF barriers, the SCO more closely resembles general brain tissue than other circumventricular organs

  17. The role of tissue renin angiotensin aldosterone system in the development of endothelial dysfunction and arterial stiffness

    Directory of Open Access Journals (Sweden)

    Annayya R Aroor

    2013-10-01

    Full Text Available Epidemiological studies support the notion that arterial stiffness is an independent predictor of adverse cardiovascular events contributing significantly to systolic hypertension, impaired ventricular-arterial coupling and diastolic dysfunction, impairment in myocardial oxygen supply and demand, and progression of kidney disease. Although arterial stiffness is associated with aging, it is accelerated in the presence of obesity and diabetes. The prevalence of arterial stiffness parallels the increase of obesity that is occurring in epidemic proportions and is partly driven by a sedentary life style and consumption of a high fructose, high salt and high fat western diet. Although the underlying mechanisms and mediators of arterial stiffness are not well understood, accumulating evidence supports the role of insulin resistance and endothelial dysfunction. The local tissue renin angiotensin aldosterone system (RAAS in the vascular tissue and immune cells and perivascular adipose tissue is recognized as an important element involved in endothelial dysfunction which contributes significantly to arterial stiffness. Activation of vascular RAAS is seen in humans and animal models of obesity and diabetes, and associated with enhanced oxidative stress and inflammation in the vascular tissue. The cross talk between angiotensin and aldosterone underscores the importance of mineralocorticoid receptors in modulation of insulin resistance, decreased bioavailability of nitric oxide, endothelial dysfunction and arterial stiffness. In addition, both innate and adaptive immunity are involved in this local tissue activation of RAAS. In this review we will attempt to present a unifying mechanism of how environmental and immunological factors are involved in this local tissue RAAS activation, and the role of this process in the development of endothelial dysfunction and arterial stiffness and targeting tissue RAAS activation.

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

    OpenAIRE

    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 investi...

  19. The renin-angiotensin-aldosterone system and calcium-regulatory hormones.

    Science.gov (United States)

    Vaidya, A; Brown, J M; Williams, J S

    2015-09-01

    There is increasing evidence of a clinically relevant interplay between the renin-angiotensin-aldosterone system and calcium-regulatory systems. Classically, the former is considered a key regulator of sodium and volume homeostasis, while the latter is most often associated with skeletal health. However, emerging evidence suggests an overlap in regulatory control. Hyperaldosteronism and hyperparathyroidism represent pathophysiologic conditions that may contribute to or perpetuate each other; aldosterone regulates parathyroid hormone and associates with adverse skeletal complications, and parathyroid hormone regulates aldosterone and associates with adverse cardiovascular complications. As dysregulation in both systems is linked to poor cardiovascular and skeletal health, it is increasingly important to fully characterize how they interact to more precisely understand their impact on human health and potential therapies to modulate these interactions. This review describes the known clinical interactions between these two systems including observational and interventional studies. Specifically, we review studies describing the inhibition of renin activity by calcium and vitamin D, and a potentially bidirectional and stimulatory relationship between aldosterone and parathyroid hormone. Deciphering these relationships might clarify variability in outcomes research, inform the design of future intervention studies and provide insight into the results of prior and ongoing intervention studies. However, before these opportunities can be addressed, more effort must be placed on shifting observational data to the proof of concept phase. This will require reallocation of resources to conduct interventional studies and secure the necessary talent. PMID:25631218

  20. Protease activated receptors (PARS) mediation in gyroxin biological activity

    International Nuclear Information System (INIS)

    Gyroxin is a serine protease enzyme from the South American rattlesnake (Crotalus durissus terrificus) venom; it is only partially characterized and has multiple activities. Gyroxin induces blood coagulation, blood pressure decrease and a neurotoxic behavior named barrel rotation. The mechanisms involved in this neurotoxic activity are not known. Whereas gyroxin is a member of enzymes with high potential to become a new drug with clinical applications such as thrombin, batroxobin, ancrod, tripsyn and kalicrein, it is important to find out how gyroxin works. The analysis on agarose gel electrophoresis and circular dichroism confirmed the molecules' integrity and purity. The gyroxin intravenous administration in mice proved its neurotoxicity (barrel rotation). In vivo studies employing intravital microscopy proved that gyroxin induces vasodilation with the participation of protease activated receptors (PARs), nitric oxide and Na+K+ATPase. The leukocytes' adherence and rolling counting indicated that gyroxin has no pro inflammatory activity. Gyroxin induced platelet aggregation, which was blocked by inhibitors of PAR1 and PAR4 receptors (SCH 79797 and tcY-NH2, respectively). Finally, it was proved that the gyroxin temporarily alter the permeability of the blood brain barrier (BBB). Our study has shown that both the protease-activated receptors and nitric oxide are mediators involved in the biological activities of gyroxin. (author)

  1. Effect of aldosterone and glycyrrhetinic acid on the protein expression of PAI-1 and p22(phox) in human mononuclear leukocytes.

    Science.gov (United States)

    Calò, Lorenzo A; Zaghetto, Francesca; Pagnin, Elisa; Davis, Paul A; De Mozzi, Paola; Sartorato, Paola; Martire, Giuseppe; Fiore, Cristina; Armanini, Decio

    2004-04-01

    Aldosterone excess can produce heart and kidney fibrosis, which seem to be related to a direct effect of aldosterone at the level of specific receptors. We report a direct, mineralocorticoid-mediated effect on the protein expression of two markers of oxidative stress after incubation of mononuclear leukocytes with 1 x 10(-8) M aldosterone (p22(phox)/beta-actin = 1.38 +/- 0.05 and PAI-1/beta-actin = 1.80 +/- 0.05). The same effect was also found with 3 x 10(-5) M glycyrrhetinic acid, the principal constituent of licorice root (p22(phox)/beta-actin = 1.37 +/- 0.97 and PAI-1/beta-actin = 1.80 +/- 0.04). The effect of both aldosterone and glycyrrhetinic acid is blocked by incubation with added 1 x 10(-6) M of receptor-antagonist canrenone. Canrenone alone did not show any effect. PAI-1 related protein was also found using 4 x 10(-9) M aldosterone. Incubations with 1 x 10(-9) M for 3 hours as well as 1 x 10(-8) M aldosterone for 5, 10, and 20 minutes were ineffective for both proteins. These data support the previous finding of an involvement of mononuclear leukocytes in the pathogenesis of the oxidative stress induced by hyperaldosteronism. In addition, the results confirm our previous data on a direct effect of glycyrrhetinic acid at the level of mineralocorticoid receptors. PMID:15070972

  2. Leptin Induces Hypertension and Endothelial Dysfunction via Aldosterone-Dependent Mechanisms in Obese Female Mice.

    Science.gov (United States)

    Huby, Anne-Cécile; Otvos, Laszlo; Belin de Chantemèle, Eric J

    2016-05-01

    Obesity is a major risk factor for cardiovascular disease in males and females. Whether obesity triggers cardiovascular disease via similar mechanisms in both the sexes is, however, unknown. In males, the adipokine leptin highly contributes to obesity-related cardiovascular disease by increasing sympathetic activity. Females secrete 3× to 4× more leptin than males, but do not exhibit high sympathetic tone with obesity. Nevertheless, females show inappropriately high aldosterone levels that positively correlate with adiposity and blood pressure (BP). We hypothesized that leptin induces hypertension and endothelial dysfunction via aldosterone-dependent mechanisms in females. Leptin control of the cardiovascular function was analyzed in female mice sensitized to leptin via the deletion of protein tyrosine phosphatase 1b (knockout) and in agouti yellow obese hyperleptinemic mice (Ay). Hypersensitivity to leptin (wild-type, 115±2; protein tyrosine phosphatase 1b knockout, 124±2 mm Hg;Pantagonism restored BP and endothelial function in protein tyrosine phosphatase 1b knockout and Ay mice. Hypersensitivity to leptin and obesity reduced BP response to ganglionic blockade in both strains and plasma catecholamine levels in protein tyrosine phosphatase 1b knockout mice. Hypersensitivity to leptin and obesity significantly increased plasma aldosterone levels and adrenal CYP11B2 expression. Chronic leptin receptor antagonism reduced aldosterone levels. Furthermore, chronic leptin and mineralocorticoid receptor blockade reduced BP and improved endothelial function in both leptin-sensitized and obese hyperleptinemic female mice. Together, these data demonstrate that leptin induces hypertension and endothelial dysfunction via aldosterone-dependent mechanisms in female mice and suggest that obesity leads to cardiovascular disease via sex-specific mechanisms. PMID:26953321

  3. Mediated Electrochemical Measurements of Intracellular Catabolic Activities of Yeast Cells

    Institute of Scientific and Technical Information of China (English)

    Jin Sheng ZHAO; Zhen Yu YANG; Yao LU; Zheng Yu YANG

    2005-01-01

    Coupling with the dual mediator system menadione/ferricyanide, microelectrode voltammetric measurements were undertaken to detect the ferrocyanide accumulations arising from the mediated reduction of ferricyanide by yeast cells. The results indicate that the dual mediator system menadione/ferricyanide could be used as a probe to detect cellular catabolic activities in yeast cells and the electrochemical response has a positive relationship with the specific growth rate of yeast cells.

  4. THE ASSOCIATIONS OF ADIPOKINES WITH SELECTED MARKERS OF THE RENIN-ANGIOTENSINOGEN-ALDOSTERONE SYSTEM: THE MULTI-ETHNIC STUDY OF ATHEROSCLEROSIS

    OpenAIRE

    Allison, Matthew A.; Jenny, Nancy Swords; McClelland, Robyn L.; Cushman, Mary; Rifkin, Dena

    2014-01-01

    Among obese individuals, increased sympathetic nervous system activity results in increased renin and aldosterone production, as well as renal tubular sodium reabsorption. This study determined the associations between adipokines and selected measures of the reninangiotensinogen-aldosterone system (RAAS). The sample was 1,970 men and women from the Multi-Ethnic Study of Atherosclerosis who were free of clinical cardiovascular disease at baseline and had blood assayed for adiponectin, leptin, ...

  5. Primary aldosteronism - recent progress and current concepts.

    Science.gov (United States)

    Kołodziejczyk-Kruk, Sylwia; Januszewicz, Włodzimierz; Pęczkowska, Mariola; Prejbisz, Aleksander; Zgliczyński, Wojciech; Januszewicz, Andrzej

    2013-01-01

    Primary aldosteronism is the commonest form of hormone-related hypertension, with an estimated prevalence of 6-13% in the generalpopulation of hypertensive patients. Among patients with resistant hypertension, the proportion of PA is even higher. Through intensiveresearch in the field of basic science and the creation of large registries of patients with PA, it is possible to understand the effect ofexcess aldosterone not only on the cardiovascular system but also on the morphology and function of the other organs. Recent researchhas highlighted the differences in the regulation of calcium metabolism in patients with adrenal adenomas and PA. A lot of attention hasbeen paid to the improvement of diagnostic methods, with particular emphasis on adrenal vein sampling, which is becoming increasinglyimportant. In recent years there have been many publications on the prevalence of mutations in the potassium channel in patients withadrenal tumours and PA. A new form of familial hyperaldosteronism - FIII, has also been distinguished. Treatment of patients with PAstill relies on the use of mineralocorticoid receptor antagonists or adrenalectomy, preferably preceded by a confirmation of aldosteronesecretion lateralisation by adrenal vein sampling. PMID:24002960

  6. Aldosterone-mineralocorticoid receptor promotes urine prostasin through glomerular barrier injury and not tissue abundance

    DEFF Research Database (Denmark)

    Stolzenburg Oxlund, Christina; Kurt, B.; Schwarzensteiner, I.;

    2015-01-01

    Objective: Low salt intake or infusion with the mineralocorticoid hormone aldosterone increases the abundance of proteolytically activated gamma ENaC in rat kidney. Prostasin is a serine proteinase GPI-anchored to the apical membrane of renal principal cells. It was hypothesized that the aldoster......Objective: Low salt intake or infusion with the mineralocorticoid hormone aldosterone increases the abundance of proteolytically activated gamma ENaC in rat kidney. Prostasin is a serine proteinase GPI-anchored to the apical membrane of renal principal cells. It was hypothesized...... and in concentrated urine samples no difference was detected between placebo and spironolactone group by ELISA while western immunoblotting showed correlation of urine prostasin with albumin and a reduction in both with spironolactone. Patients with proteinuria displayed elevated u-prostasin compared to control...

  7. The associations of adipokines with selected markers of the renin-angiotensinogen-aldosterone system: the multi-ethnic study of atherosclerosis.

    Science.gov (United States)

    Allison, M A; Jenny, N S; McClelland, R L; Cushman, M; Rifkin, D

    2015-02-01

    Among obese individuals, increased sympathetic nervous system (SNS) activity results in increased renin and aldosterone production, as well as renal tubular sodium reabsorption. This study determined the associations between adipokines and selected measures of the renin-angiotensinogen-aldosterone system (RAAS). The sample consisted of 1970 men and women from the Multi-Ethnic Study of Atherosclerosis who were free of clinical cardiovascular disease at baseline and had blood assayed for adiponectin, leptin, plasma renin activity (PRA) and aldosterone. The mean age was 64.7 years and 50% were female. The mean (s.d.) PRA and aldosterone were 1.45 (0.56) ng ml(-1) and 150.1 (130.5) pg ml(-1), respectively. After multivariable adjustment, a 1-s.d. increment of leptin was associated with a 0.55 ng ml(-1) higher PRA and 8.4 pg ml(-1) higher aldosterone (Pleptin and adiponectin were not materially changed with additional adjustment for PRA. Exclusion of those taking antihypertensive medications modestly attenuated the associations. The associations between leptin and both PRA and aldosterone were not different by gender but were significantly stronger among non-Hispanic Whites and Chinese Americans than African and Hispanic Americans (Pleptin may be relevant to blood pressure regulation via the RAAS, in that the associations appear to be robust to antihypertension medication use and that the associations are likely different by ethnicity. PMID:24919752

  8. Angiotensin Converting Enzyme Activity in Alopecia Areata

    OpenAIRE

    Mohammad Reza Namazi; Armaghan Ashraf; Farhad Handjani; Ebrahim Eftekhar; Amir Kalafi

    2014-01-01

    Background. Alopecia areata (AA) is a chronic inflammatory disease of the hair follicle. The exact pathogenesis of AA remains unknown, although recent studies support a T-cell mediated autoimmune process. On the other hand, some studies have proposed that the renin-angiotensin-aldosterone system (RAAS) may play a role in autoimmunity. Therefore, we assessed serum activity of angiotensin converting enzyme (ACE), a component of this system, in AA. Methods. ACE activity was measured in the sera ...

  9. CACNA1H(M1549V) Mutant Calcium Channel Causes Autonomous Aldosterone Production in HAC15 Cells and Is Inhibited by Mibefradil.

    Science.gov (United States)

    Reimer, Esther N; Walenda, Gudrun; Seidel, Eric; Scholl, Ute I

    2016-08-01

    We recently demonstrated that a recurrent gain-of-function mutation in a T-type calcium channel, CACNA1H(M1549V), causes a novel Mendelian disorder featuring early-onset primary aldosteronism and hypertension. This variant was found independently in five families. CACNA1H(M1549V) leads to impaired channel inactivation and activation at more hyperpolarized potentials, inferred to cause increased calcium entry. We here aimed to study the effect of this variant on aldosterone production. We heterologously expressed empty vector, CACNA1H(WT) and CACNA1H(M1549V) in the aldosterone-producing adrenocortical cancer cell line H295R and its subclone HAC15. Transfection rates, expression levels, and subcellular distribution of the channel were similar between CACNA1H(WT) and CACNA1H(M1549V). We measured aldosterone production by an ELISA and CYP11B2 (aldosterone synthase) expression by real-time PCR. In unstimulated cells, transfection of CACNA1H(WT) led to a 2-fold increase in aldosterone levels compared with vector-transfected cells. Expression of CACNA1H(M1549V) caused a 7-fold increase in aldosterone levels. Treatment with angiotensin II or increased extracellular potassium levels further stimulated aldosterone production in both CACNA1H(WT)- and CACNA1H(M1549V)-transfected cells. Similar results were obtained for CYP11B2 expression. Inhibition of CACNA1H channels with the T-type calcium channel blocker Mibefradil completely abrogated the effects of CACNA1H(WT) and CACNA1H(M1549V) on CYP11B2 expression. These results directly link CACNA1H(M1549V) to increased aldosterone production. They suggest that calcium channel blockers may be beneficial in the treatment of a subset of patients with primary aldosteronism. Such blockers could target CACNA1H or both CACNA1H and the L-type calcium channel CACNA1D that is also expressed in the adrenal gland and mutated in patients with primary aldosteronism. PMID:27258646

  10. The role of aldosterone receptor blocker therapy in hypertension and heart failure

    Directory of Open Access Journals (Sweden)

    Giuseppina Santese

    2015-09-01

    Full Text Available The aldosterone receptor blocker therapy as an “add-on” to hypotensive therapy is an excellent therapeutic strategy that has proved to be particularly effective in treating refractory hypertension, hypertension with organ damage and overweight hypertensive patients. Aldosterone receptor blockers are extremely useful in inhibiting hormonal activation linked with heart failure: they have cardioprotective effects not only during full-blown heart failure, but also in its early stages, and this effect can be observed even more frequently in heart failures with metabolic syndrome. The use of molecules such as canrenone with a favorable tolerability profile ensures a better tolerability ratio by providing benefits linked to fewer drug interactions, lower incidence of side effects and improved therapy adherence.

  11. Systemic effects of angiotensin III in conscious dogs during acute double blockade of the renin-angiotensin-aldosterone-system

    DEFF Research Database (Denmark)

    Gammelgaard, Iben; Wamberg, Søren; Bie, Peter

    2006-01-01

    increased mean arterial blood pressure (+14 +/- 4 mmHg) and plasma aldosterone by 79% (+149 +/- 17 pg mL(-1)) and reduced plasma renin activity and sodium excretion (-41 +/- 16 mIU L(-1) and -46 +/- 6 micromol min(-1) respectively). AngIII mimicked these effects and the magnitude of AngIII responses was...

  12. The role of the epithelial Na+ channel (ENaC in high AVP but low aldosterone states

    Directory of Open Access Journals (Sweden)

    James D Stockand

    2012-07-01

    Full Text Available Due to the abundance of seminal discoveries establishing a strong causal relation between changes in aldosterone signaling, the activity of the epithelial Na+ channel (ENaC and blood pressure, the role of ENaC in health and disease is understood almost exclusively through the concept that this channel functions (in the distal nephron as a key end-effector controlling renal sodium excretion during feedback regulation of blood pressure by the renin-angiotensin-aldosterone system (RAAS. Recent findings of aldosterone-independent stimulation of ENaC by vasopressin challenge the completeness of dogmatic understanding where ENaC serves solely as an end-effector of the RAAS important for control of sodium balance. Rather the consequences of activating ENaC in the distal nephron appear to depend on whether the channel is activated in the absence (by aldosterone or presence (by AVP of simultaneous activation of aquaporin 2 water channels. Thus, a unifying paradigm has ENaC at the junction of two signaling systems that sometimes must compete: one controlling and responding to changes in sodium balance, perceived as mean arterial pressure, and the other water balance, perceived as plasma osmolality.

  13. History of aldosterone on its 50th birthday.

    Science.gov (United States)

    Fiore, Cristina; Calò, Lorenzo A; Colombo, Lorenzo; Grimm, Clarence E; Armanini, Decio

    2006-01-01

    The paper describes the impact of mineralocorticoid substances on water regulation from Theophrastus (IV century B.C.) to Thomas Addison (1849). It also opens to the missed discovery of aldosterone of I.A. Macchi. PMID:16874725

  14. Behaviour analysis for web-mediated active learning

    OpenAIRE

    Pahl, Claus

    2007-01-01

    Software-mediated learning requires adjustments in the teaching and learning process. In particular active learning facilitated through interactive learning software differs from traditional instructor-oriented, classroom-based teaching. We present behaviour analysis techniques for Web-mediated learning. Motivation, acceptance of the learning approach and technology, learning organisation and actual tool usage are aspects of behaviour that require different analysis techniques to be used. ...

  15. Primary aldosteronism caused by unilateral adrenal hyperplasia: rethinking the accuracy of imaging studies.

    Science.gov (United States)

    Chen, Su-Yu; Shen, Sjen-Jung; Chou, Chien-Wen; Yang, Chwen-Yi; Cheng, Hon-Mei

    2006-03-01

    A rare type of aldosteronism, known as unilateral adrenal hyperplasia (UAH), is difficult to diagnose, not only because it fails to conform to the typical common subtypes, but also because imaging results are unreliable. We report 2 Taiwanese patients with UAH. Case 1 was a 44-year-old man with 2 episodes of hypokalemic paralysis. Hypertension and suppressed plasma renin activity (PRA) with elevated plasma aldosterone concentration (PAC) were observed. Abdominal computed tomography (CT) and magnetic resonance imaging (MRI) showed a right adrenal mass, but adrenal scintigraphy revealed no definite laterality. The patient underwent a laparoscopic right adrenalectomy. Adrenal cortical hyperplasia was discovered from results of the histologic analysis. Case 2 was a 33-year-old woman referred for hypokalemia, hypertension, and a left adrenal mass found on a CT scan. However, MRI revealed normal adrenal glands. The adrenal vein sampling for PAC showed overproduction of PAC from the left adrenal gland. A laparoscopic left adrenalectomy was done. Pathology results revealed micronodular cortical hyperplasia with central hemorrhage. Blood pressure, plasma potassium, aldosterone, and renin activity levels returned to normal after operation in both cases. Both patients have been well for 3 years and 16 months, respectively, after surgery. We review the literature and discuss the limitations of imaging studies. PMID:16599018

  16. Free radical-mediated activation of hydrazine derivatives.

    OpenAIRE

    Kalyanaraman, B.; Sinha, B. K.

    1985-01-01

    Hydrazines are known to undergo oxidative activation in several enzymatic systems in vitro. Free radicals or carbonium ions have been proposed as active intermediates during such activation. The toxic effects elicited by hydrazines have also been linked to free radical-mediated activation. In this report, we have reviewed the identification of organic free radicals from hydrazines by direct ESR and ESR-spin trapping.

  17. Aldosterone induces myofibroblast EGF secretion to regulate epithelial colonic permeability.

    Science.gov (United States)

    Miró, Lluïsa; Pérez-Bosque, Anna; Maijó, Mònica; Amat, Concepció; Naftalin, Richard J; Moretó, Miquel

    2013-05-01

    In vivo studies show that raised aldosterone (Aldo) during low-Na adaptation regulates the growth of pericryptal myofibroblasts and reduces the permeability of the colonic epithelium. The aim of this study was to reproduce in vitro the in vivo condition of increased Aldo using human CCD-18Co myofibroblasts and T84 colonic epithelial cells to measure myofibroblast and epithelial proliferation and the expression of intercellular junction proteins. Proliferation was quantified by measuring 5-bromo-2'-deoxyuridine incorporation. The myofibroblast expression of EGF, VEGFa, and transforming growth factor-β1 (TGF-β1) was measured by real-time PCR and the expression of junctional complex proteins by Western blot. Aldo stimulated the proliferation of myofibroblasts by 70% (P < 0.05) and increased EGF mRNA expression by 30% (P < 0.05) without affecting VEGFa and TGF-β1. EGF concentration in the incubation medium increased by 30% (P < 0.05) 24 h after Aldo addition, and these effects were prevented by the addition of spironolactone. Myofibroblast proliferation in response to Aldo was mediated by EGF receptor (EGFR) and involved both MAPKK and phosphatidylinositol 3-kinase pathways. When T84 cells were incubated with medium from myofibroblasts stimulated with Aldo (conditioned medium), the expression of β-catenin and claudin IV was increased by 30% (P < 0.05) and proliferation by 40% (P < 0.05). T84 proliferation decreased when α-EGF, or the EGFR antagonist AG1478, was present. Results in vivo indicate that rats fed a low-salt diet showed an increased expression of EGF and EGFR in the colonic mucosa. These results support the view that changes in colonic permeability during low-Na adaptation are mediated by the EGF secreted by myofibroblasts in response to raised Aldo. PMID:23467299

  18. Uranium-mediated activation of small molecules.

    Science.gov (United States)

    Arnold, Polly L

    2011-08-28

    Molecular complexes of uranium are capable of activating a range of industrially and economically important small molecules such as CO, CO(2), and N(2); new and often unexpected reactions provide insight into an element that needs to be well-understood if future clean-energy solutions are to involve nuclear power. PMID:21614341

  19. Aldose reductase mediates retinal microglia activation.

    Science.gov (United States)

    Chang, Kun-Che; Shieh, Biehuoy; Petrash, J Mark

    2016-04-29

    Retinal microglia (RMG) are one of the major immune cells in charge of surveillance of inflammatory responses in the eye. In the absence of an inflammatory stimulus, RMG reside predominately in the ganglion layer and inner or outer plexiform layers. However, under stress RMG become activated and migrate into the inner nuclear layer (INL) or outer nuclear layer (ONL). Activated RMG in cell culture secrete pro-inflammatory cytokines in a manner sensitive to downregulation by aldose reductase inhibitors. In this study, we utilized CX3CR1(GFP) mice carrying AR mutant alleles to evaluate the role of AR on RMG activation and migration in vivo. When tested on an AR(WT) background, IP injection of LPS induced RMG activation and migration into the INL and ONL. However, this phenomenon was largely prevented by AR inhibitors or in AR null mice, or was exacerbated in transgenic mice that over-express AR. LPS-induced increases in ocular levels of TNF-α and CX3CL-1 in WT mice were substantially lower in AR null mice or were reduced by AR inhibitor treatment. These studies demonstrate that AR expression in RMG may contribute to the proinflammatory phenotypes common to various eye diseases such as uveitis and diabetic retinopathy. PMID:27033597

  20. Enhanced Soluble Serum CD40L and Serum P-Selectin Levels in Primary Aldosteronism.

    Science.gov (United States)

    Petramala, L; Iacobellis, G; Carnevale, R; Marinelli, C; Zinnamosca, L; Concistrè, A; Galassi, M; Iannucci, G; Lucia, P; Pignatelli, P; Ciardi, A; Violi, F; De Toma, G; Letizia, C

    2016-07-01

    Primary aldosteronism (PA) is one of the most frequent forms of secondary hypertension, associated with atherosclerosis and higher risk of cardiovascular events. Platelets play a key role in the atherosclerotic process. The aim of the study was to evaluate the platelet activation by measuring serum levels of soluble CD40L (sCD40L) and P-selectin (sP-selectin) in consecutive PA patients [subgroup: aldosterone-secreting adrenal adenoma (APA) and bilateral adrenal hyperplasia (IHA)], matched with essential hypertensive (EH) patients. The subgroup of APA patients was revaluated 6-months after unilateral adrenalectomy. In all PA group, we measured higher serum levels of both sP-selectin (14.29±9.33 pg/ml) and sCD40L (9.53±4.2 ng/ml) compared to EH patients (9.39±5.3 pg/ml and 3.54±0.94 ng/ml, respectively; pAPA, PA patients showed significant reduction of blood pressure (BP) values, plasma aldosterone (PAC) levels and ARR-ratio, associated with a significant reduction of sP-selectin (16.74±8.9 pg/ml vs. 8.1±3.8 pg/ml; pAPA patients (r=0.54; pAPA patients. PMID:27101095

  1. Active DNA Demethylation Mediated by DNA Glycosylases

    OpenAIRE

    Zhu, Jian-Kang

    2009-01-01

    Active DNA demethylation is involved in many vital developmental and physiological processes of plants and animals. Recent genetic and biochemical studies in Arabidopsis have demonstrated that a subfamily of DNA glycosylases function to promote DNA demethylation through a base excision-repair pathway. These specialized bifunctional DNA glycosylases remove the 5-methylcytosine base and then cleave the DNA backbone at the abasic site, resulting in a gap that is then filled with an unmethylated ...

  2. Aldosterone receptor blockers spironolactone and canrenone: two multivalent drugs.

    Science.gov (United States)

    Armanini, Decio; Sabbadin, Chiara; Donà, Gabriella; Clari, Giulio; Bordin, Luciana

    2014-05-01

    Canrenone is a derivative of spironolactone with lower antiandrogen activity. The drug is used only in few countries and can block all the side effects of aldosterone (ALDO). The drug is effective even in the presence of normal concentrations of ALDO. Mineralcorticoid receptor antagonists block the inflammatory activity of ALDO at the level of target tissues as heart, vessels and mononuclear leukocytes. Canrenone reduces the progression of insulin resistance and of microalbuminuria in type 2 diabetes and other related diseases. Both canrenone and hydrochlorothiazide can enhance the effect of treatment with ACE inhibitors and angiotensin II receptor blockers on microalbuminuria, but ALDO receptor blockers are more active. This different action is due to the fact that only canrenone blocks mineralocorticoid receptors. Serum potassium and renal function should be monitored before and during the treatment. ALDO receptor blockers are recommended in addition to polytherapy for resistant hypertension, but there are no studies on the effect of the drug as first-choice therapy. PMID:24617854

  3. Aldosterone response to sodium deprivation and angiotensin II in patients with hypopituitarism.

    Science.gov (United States)

    Seifert, C; Oelkers, W

    1981-03-01

    Unknown pituitary factor(s) apart from ACTH may participate in the regulation of aldosterone (aldo) secretion in man. We investigated whether the 'sensitization' of the zona glomerulosa against angiotensin II (A II) by sodium deficiency was mediated by the pituitary gland. A II was infused in stepwise increasing doses (2, 4, 8 ng/kg/min) into 5 normal subjects (N) and into 8 patients with hypopituitarism (H) before and after 4 days on low sodium diet. Mean cumulative sodium balance after the low sodium diet was -145mM in N and -165mM in H. Plasma-aldo and aldo-excretion rate on the normal sodium diet were slightly higher in H than in N but rose less than normal during sodium depletion in H. Plasma A II and renin activity on normal sodium were slightly higher in H than in N, but the increase on the low sodium diet was blunted in H. The stimulation of plasma-aldo by A II infusion was similar in both groups on the normal sodium diet. In both groups, the response of P-aldo to A II infusion was greater in the sodium deplete than in the replete state, although 'sensitization' was slightly less marked in H than in N. This may be due to the blunted rise of plasma-A II after sodium loss in H, which may also account for abnormalities in the blood pressure response in the H group. Altogether, the results speak against a direct involvement of the pituitary gland in 'sensitization', but an indirect influence through unexplained abnormalities in renin secretion is possible. PMID:7211097

  4. A Rare Cause of Hypokalemia: Aldosterone-Secreting Adrenocortical Carcinoma Dear Editor,

    Directory of Open Access Journals (Sweden)

    Ethem Turgay Cerit

    2014-03-01

    Full Text Available Adrenocortical carcinoma (ACC is a rare malignancy accounting for 0.05-0.2% of all cancers (1. Determinants of prognosis are the stage of disease and completeness of resection(2. Approximately 60% of ACCs are hormonally active and glucocorticoids and/or androgens are most frequently over-secreted (2. Rapid development of signs and symptoms of Cushing’s syndrome is the most frequent presentation (3. Aldosterone-secreting ACC is extremely uncommon, comprising 0% to 7% of all functioning ACCs and presents with severe hypertension and profound hypokalemia (4. Here we report a case diagnosed as aldosterone producing adrenocortical carcinoma presented with severe hypokalemia and hypertension. A 32-year-old man referred to our instution because of pain and marked weakness especially in his lower extremities for 2 months. On admission his blood pressure was 180 mmHg systolic and 110 mmHg diastolic. Laboratory investigation revealed severe hypokalemia (2.6 mmol/l (normal: 3.5-5.5 mmol/l, elevated serum aldosterone (39.0 ng/dl (normal: 0.8-13 ng/dl with suppressed plasma renin activity (0.07 ng/ml/h. Serum sodium level was 142 mmol/l (normal: 135-146 mmol/l. Serum aldosterone level was not supressed (38.2 ng/dl after saline infusion test. Serum dehydroepiandrosterone sulfate (DHEA-SO4 was 150 mcg/dl (normal: 80-560, Δ4-androstenedione was 1.91 ng/ml (normal: 0.5-4.8 and total testosterone was 447.3 ng/dl (normal: 229.8-799.8 (Table 1. Suppressed renin levels, increased aldosterone levels with an aldosterone/renin ratio >30 were suggestive findings of aldosterone-producing adenoma of the adrenal gland or bilateral adrenal hyperplasia. Computed tomography demonstrated a large (4.6 cm left-sided adrenal tumour which is heterogeneous and has lobulated margin without a contrasting pattern of adenoma (Figure 1. 24-h urinary catecholamines and low-dose dexamethasone-suppressed plasma cortisol concentrations were all normal. At surgery, an adrenal mass (70

  5. Molecular and cellular mechanisms of aldosterone producing adenoma development

    Directory of Open Access Journals (Sweden)

    Sheerazed eBoulkroun

    2015-06-01

    Full Text Available Primary aldosteronism (PA is the most common form of secondary hypertension with an estimated prevalence of ~10% in referred patients. PA occurs as a result of a dysregulation of the normal mechanisms controlling adrenal aldosterone production. It is characterized by hypertension with low plasma renin and elevated aldosterone and often associated with hypokalemia. The two major causes of PA are unilateral aldosterone producing adenoma (APA and bilateral adrenal hyperplasia, accounting together for ~95% of cases. In addition to the well-characterized effect of excess mineralocorticoids on blood pressure, high levels of aldosterone also have cardiovascular, renal and metabolic consequences. Hence, long-term consequences of PA include increased risk of coronary artery disease, myocardial infarction, heart failure and atrial fibrillation. Despite recent progress in the management of patients with PA, critical issues related to diagnosis, subtype differentiation and treatment of non-surgically correctable forms still persist. A better understanding of the pathogenic mechanisms of the disease should lead to the identification of more reliable diagnostic and prognostic biomarkers for a more sensitive and specific screening and new therapeutic options. In this review we will summarize our current knowledge on the molecular and cellular mechanisms of APA development. On one hand, we will discuss how various animal models have improved our understanding of the pathophysiology of excess aldosterone production. On the other hand, we will summarize the major advances made during the last few years in the genetics of APA due to transcriptomic studies and whole exome sequencing. The identification of recurrent and somatic mutations in genes coding for ion channels (KCNJ5 and CACNA1D and ATPases (ATP1A1 and ATP2B3 allowed highlighting the central role of calcium signaling in autonomous aldosterone production by the adrenal.

  6. Meta-analysis of effects of obstructive sleep apnea on the renin-angiotensin-aldosterone system

    Science.gov (United States)

    Jin, Ze-Ning; Wei, Yong-Xiang

    2016-01-01

    Background Obstructive sleep apnea (OSA) is the most common cause of resistant hypertension, which has been proposed to result from activation of the renin–angiotensin–aldosterone system (RAAS). We meta-analyzed the effects of OSA on plasma levels of RAAS components. Methods Full-text studies published on MEDLINE and EMBASE analyzing fasting plasma levels of at least one RAAS component in adults with OSA with or without hypertension. OSA was diagnosed as an apnea-hypopnea index or respiratory disturbance index ≥ 5. Study quality was evaluated using the Newcastle-Ottawa Scale, and heterogeneity was assessed using the I2 statistic. Results from individual studies were synthesized using inverse variance and pooled using a random-effects model. Subgroup analysis, sensitivity analysis, and meta-regression were performed, and risk of publication bias was assessed. Results The meta-analysis included 13 studies, of which 10 reported results on renin (n = 470 cases and controls), 7 on angiotensin II (AngII, n = 384), and 9 on aldosterone (n = 439). AngII levels were significantly higher in OSA than in controls [mean differences = 3.39 ng/L, 95% CI: 2.00–4.79, P < 0.00001], while aldosterone levels were significantly higher in OSA with hypertension than OSA but not with hypertension (mean differences = 1.32 ng/dL, 95% CI: 0.58–2.07, P = 0.0005). Meta-analysis of all studies suggested no significant differences in aldosterone between OSA and controls, but a significant pooled mean difference of 1.35 ng/mL (95% CI: 0.88–1.82, P < 0.00001) emerged after excluding one small-sample study. No significant risk of publication bias was detected among all included studies. Conclusions OSA is associated with higher AngII and aldosterone levels, especially in hypertensive patients. OSA may cause hypertension, at least in part, by stimulating RAAS activity.

  7. Rapid actions of aldosterone in vascular health and disease - friend or foe?

    DEFF Research Database (Denmark)

    Skøtt, Ole; Uhrenholt, Torben Rene; Schjerning, Jeppe;

    2006-01-01

    The mineralocorticoid receptor (MR) and the enzyme 11betahydroxysteroid dehydrogenase type 2, which confers aldosterone specificity to the MR, are present in endothelium and vascular smooth muscle. In several pathological conditions aldosterone promotes vascular damage by formation of reactive ox...

  8. Bilateral Adrenocortical Masses Producing Aldosterone and Cortisol Independently.

    Science.gov (United States)

    Lee, Seung Eun; Kim, Jae Hyeon; Lee, You Bin; Seok, Hyeri; Shin, In Seub; Eun, Yeong Hee; Kim, Jung Han; Oh, Young Lyun

    2015-12-01

    A 31-year-old woman was referred to our hospital with symptoms of hypertension and bilateral adrenocortical masses with no feature of Cushing syndrome. The serum aldosterone/renin ratio was elevated and the saline loading test showed no suppression of the plasma aldosterone level, consistent with a diagnosis of primary hyperaldosteronism. Overnight and low-dose dexamethasone suppression tests showed no suppression of serum cortisol, indicating a secondary diagnosis of subclinical Cushing syndrome. Adrenal vein sampling during the low-dose dexamethasone suppression test demonstrated excess secretion of cortisol from the left adrenal mass. A partial right adrenalectomy was performed, resulting in normalization of blood pressure, hypokalemia, and high aldosterone level, implying that the right adrenal mass was the main cause of the hyperaldosteronism. A total adrenalectomy for the left adrenal mass was later performed, resulting in a normalization of cortisol level. The final diagnosis was bilateral adrenocortical adenomas, which were secreting aldosterone and cortisol independently. This case is the first report of a concurrent cortisol-producing left adrenal adenoma and an aldosterone-producing right adrenal adenoma in Korea, as demonstrated by adrenal vein sampling and sequential removal of adrenal masses. PMID:26248855

  9. Evaluation of aldosterone excretion in very low birth weight infants.

    Science.gov (United States)

    Abdel Mohsen, Abdel Hakeem; Taha, Gamal; Kamel, Bothina A; Maksood, Mohamed Abdel

    2016-01-01

    Data about aldosterone production and excretion in the neonatal period are still few and controversial. Our objectives are to assess urinary aldosterone excretion (UAE) in very low birth weight (VLBW) infants and to identify clinical and biochemical variables that may influence this excretion. Thirty VLBW infants (14 males and 16 females), their gestational age value was 0.176 ± 0.05 μg/24 h and the mean absolute UAE was 1906 ± 271 pg/mL. There was a statistically significant positive correlation between UAE and gestational age and birth weight; also, infants with respiratory distress syndrome had higher urinary aldosterone levels than infants without respiratory distress. Only plasma sodium was a significant independent factor that negatively influenced UAE on linear regression analysis. The renin-angiotensin-aldosterone system of VLBW infants seems to be able, even immediately after birth, to respond to variations of plasma sodium concentrations; measurement of UAE constitutes an interesting method to determine aldosterone production in VLBW infants. PMID:27424689

  10. Effect and mechanism of poly (ADP-ribose) polymerase-1 in aldosterone-induced apoptosis

    OpenAIRE

    Qiao, Weiwei; Zhang, Weili; Shao, Shuhong; GAI, YUSHENG; Zhang, Mingxiang

    2015-01-01

    The present study aimed to investigate the effects of aldosterone on vascular endothelial cells and the viability of poly (ADP-ribose) polymerase 1 (PARP1) in cells, and to examine the molecular mechanisms underlying the effects of aldosterone on vascular endothelial cell injury. Cultured endothelial cells were treated either with different concentrations of aldosterone for the same duration or with the same concentrations of aldosterone for different durations, and the levels of apoptosis an...

  11. Alterations in vascular function in primary aldosteronism: a cardiovascular magnetic resonance imaging study

    OpenAIRE

    Mark, P. B.; Boyle, S; Zimmerli, L U; McQuarrie, E.P.; Delles, C.; Freel, E. M.

    2014-01-01

    Introduction: Excess aldosterone is associated with increased cardiovascular risk. Aldosterone has a permissive effect on vascular fibrosis. Cardiovascular magnetic resonance imaging (CMR) allows study of vascular function by measuring aortic distensibility. We compared aortic distensibility in primary aldosteronism (PA), essential hypertension (EH) and normal controls and explored the relationship between aortic distensibility and pulse wave velocity (PWV). Methods: We studied PA (n=14)...

  12. A case of bilateral aldosterone-producing adenomas differentiated by segmental adrenal venous sampling for bilateral adrenal sparing surgery.

    Science.gov (United States)

    Morimoto, R; Satani, N; Iwakura, Y; Ono, Y; Kudo, M; Nezu, M; Omata, K; Tezuka, Y; Seiji, K; Ota, H; Kawasaki, Y; Ishidoya, S; Nakamura, Y; Arai, Y; Takase, K; Sasano, H; Ito, S; Satoh, F

    2016-06-01

    Primary aldosteronism due to unilateral aldosterone-producing adenoma (APA) is a surgically curable form of hypertension. Bilateral APA can also be surgically curable in theory but few successful cases can be found in the literature. It has been reported that even using successful adrenal venous sampling (AVS) via bilateral adrenal central veins, it is extremely difficult to differentiate bilateral APA from bilateral idiopathic hyperaldosteronism (IHA) harbouring computed tomography (CT)-detectable bilateral adrenocortical nodules. We report a case of bilateral APA diagnosed by segmental AVS (S-AVS) and blood sampling via intra-adrenal first-degree tributary veins to localize the sites of intra-adrenal hormone production. A 36-year-old man with marked long-standing hypertension was referred to us with a clinical diagnosis of bilateral APA. He had typical clinical and laboratory profiles of marked hypertension, hypokalaemia, elevated plasma aldosterone concentration (PAC) of 45.1 ng dl(-1) and aldosterone renin activity ratio of 90.2 (ng dl(-1) per ng ml(-1 )h(-1)), which was still high after 50 mg-captopril loading. CT revealed bilateral adrenocortical tumours of 10 and 12 mm in diameter on the right and left sides, respectively. S-AVS confirmed excess aldosterone secretion from a tumour segment vein and suppressed secretion from a non-tumour segment vein bilaterally, leading to the diagnosis of bilateral APA. The patient underwent simultaneous bilateral sparing adrenalectomy. Histopathological analysis of the resected adrenals together with decreased blood pressure and PAC of 5.2 ng dl(-1) confirmed the removal of bilateral APA. S-AVS was reliable to differentiate bilateral APA from IHA by direct evaluation of intra-adrenal hormone production. PMID:26538381

  13. Clinicopathological features of primary aldosteronism associated with subclinical Cushing's syndrome

    International Nuclear Information System (INIS)

    Primary aldosteronism (PA), an autonomous aldosterone hypersecretion from adrenal adenoma and/or hyperplasia, and subclinical Cushing syndrome (SCS), a mild but autonomous cortisol hypersecretion from adrenal adenoma without signs or symptoms of Cuhing's syndrome, are now well-recognized clinical entities of adrenal incidentaloma. However, the clinicopathological features of PA associated with SCS (PA/SCS) remain unknown. The present study was undertaken to study the prevalence of PA/SCS among PA patients diagnosed at our institute, and characterize their clinicopathlogical features. The prevalence of PA/SCS was 8 of 38 PA patients (21%) studied. These 8 PA/SCS patients were significantly older and had larger tumor, higher serum potassium levels, lower basal plasma levels of aldosterone, adrenocorticotropic hormone (ACTH) and dehydroepiandrosterone sulfate (DHEA-S) as well as lower response of aldosterone after ACTH stimulation than those in 12 patients with aldosterone-producing adenoma without hypercortisolism. All 8 PA/SCS patients showed unilateral uptake by adrenal scintigraphy at the ipsilateral side, whereas the laterality of aldosterone hypersecretion as determined by adrenal venous sampling varied from ipsilateral (3), contralateral (2), and bilateral side (2). 6 PA/SCS patients who underwent adrenalectomy required hydrocortisone replacement postoperatively. Histopathological analysis of the resected adrenal tumors from 5 PA/SCS patients revealed a single adenoma in 3, and double adenomas in 2, with varying degrees of positive immunoreactivities for steroidgenic enzymes 3β-hydroxysteroid dehydrogenase (HSD), P450C17) by immunohistochemical study as well as CYP11B2 mRNA expression as measured by real-time radiotherapy-polymerase chain reaction (RT-PCR). In conclusion, PA/SCS consists of a variety of adrenal pathologies so that therapeutic approach differs depending on the disease subtype. (author)

  14. Transdermal contraception and the renin-angiotensin-aldosterone system in premenopausal women.

    Science.gov (United States)

    Odutayo, Ayodele; Cherney, David; Miller, Judith; Ahmed, Sofia B; Lai, Vesta; Dunn, Sheila; Pun, Nicole; Moineddin, Rahim; Hladunewich, Michelle A

    2015-03-15

    The oral contraceptive pill (OCP) activates the renin-angiotensin-aldosterone system (RAAS) through first-pass hepatic metabolism. Although usually benign, RAAS activation may have detrimental effects on renal and hemodynamic function in some women. Since combined hormonal contraception with the transdermal patch (EVRA) does not undergo first-pass hepatic metabolism, we hypothesized that the RAAS response would be different from that of OCP subjects. Thirty-five nonsmoking, premenopausal women (15 control subjects, 10 OCP subjects, and 10 contraceptive patch subjects) without evidence of cardiovascular disease, renal disease, or diabetes were studied. Baseline angiotensinogen, renin, angiotensin II, aldosterone, and plasma renin activity were assessed along with hormonal and hemodynamic responses to simulated orthostatic stress using incremental lower body negative pressure (LBNP; -15, -25, and -40 mmHg). Baseline levels of angiotensinogen, angiotensin II, and plasma renin activity were significantly higher in OCP subjects compared with normotensive control and contraceptive patch subjects (P versus control subjects only (P < 0.05). Plasma renin levels were significantly lower at baseline in contraceptive patch subjects compared with normotensive control and OCP subjects (P < 0.05). In response to LBNP, increases in renin, angiotensin II, and aldosterone were attenuated in contraceptive patch subjects in conjunction with an exaggerated decline in mean arterial pressure (P < 0.05 vs. control and OCP subjects). The contraceptive patch in healthy premenopausal women is associated with an impaired ability to maintain blood pressure in response to LBNP, possibly due to insensitivity of the endogenous RAAS. Further evaluation may be beneficial in women with kidney disease. PMID:25587124

  15. Severe hypertension in primary aldosteronism and good response to surgery.

    Science.gov (United States)

    Clarke, D; Wilkinson, R; Johnston, I D; Hacking, P M; Haggith, J W

    1979-03-01

    11 patients with primary aldosteronism have been encountered over 11 years and submitted to surgery in a provincial teaching hospital serving a population of 3 million. Contrary to classical teaching, the hypertension has usually been very severe. Precise identification of the site of the lesion preoperatively has been possible by the measurement of adrenal-vein aldosterone levels, and results of surgery have been excellent. The iodocholesterol adrenal scan also correctly identified the site of the adenoma in 5 out of 7 patients in which it was used. Adrenal venography was of little value except in siting catheters. PMID:85065

  16. Spillover-mediated feedforward-inhibition functionally segregates interneuron activity

    Science.gov (United States)

    Coddington, Luke T.; Rudolph, Stephanie; Lune, Patrick Vande; Overstreet-Wadiche, Linda; Wadiche, Jacques I.

    2013-01-01

    Summary Neurotransmitter spillover represents a form of neural transmission not restricted to morphologically defined synaptic connections. Communication between climbing fibers (CFs) and molecular layer interneurons (MLIs) in the cerebellum is mediated exclusively by glutamate spillover. Here, we show how CF stimulation functionally segregates MLIs based on their location relative to glutamate release. Excitation of MLIs that reside within the domain of spillover diffusion coordinates inhibition of MLIs outside the diffusion limit. CF excitation of MLIs is dependent on extrasynaptic NMDA receptors that enhance the spatial and temporal spread of CF signaling. Activity mediated by functionally segregated MLIs converges onto neighboring Purkinje cells (PCs) to generate a long-lasting biphasic change in inhibition. These data demonstrate how glutamate release from single CFs modulates excitability of neighboring PCs, thus expanding the influence of CFs on cerebellar cortical activity in a manner not predicted by anatomical connectivity. PMID:23707614

  17. PKG-1α mediates GATA4 transcriptional activity.

    Science.gov (United States)

    Ma, Yanlin; Wang, Jun; Yu, Yanhong; Schwartz, Robert J

    2016-06-01

    GATA4, a zinc-finger transcription factor, is central for cardiac development and diseases. Here we show that GATA4 transcriptional activity is mediated by cell signaling via cGMP dependent PKG-1α activity. Protein kinase G (PKG), a serine/tyrosine specific kinase is the major effector of cGMP signaling. We observed enhanced transcriptional activity elicited by co-expressed GATA4 and PKG-1α. Phosphorylation of GATA4 by PKG-1α was detected on serine 261 (S261), while the C-terminal activation domain of GATA4 associated with PKG-1α. GATA4's DNA binding activity was enhanced by PKG-1α via by both phosphorylation and physical association. More importantly, a number of human disease-linked GATA4 mutants exhibited impaired S261 phosphorylation, pointing to defective S261 phosphorylation in the elaboration of human heart diseases. We showed S261 phosphorylation was favored by PKG-1α but not by PKA, and several other kinase signaling pathways such as MAPK and PKC. Our observations demonstrate that cGMP-PKG signaling mediates transcriptional activity of GATA4 and links defective GATA4 and PKG-1α mutations to the development of human heart disease. PMID:26946174

  18. Somatic and germline CACNA1D calcium channel mutations in aldosterone-producing adenomas and primary aldosteronism

    OpenAIRE

    Scholl, Ute I; Goh, Gerald; Stölting, Gabriel; de Oliveira, Regina Campos; Choi, Murim; Overton, John D; Fonseca, Annabelle L.; Korah, Reju; Lee F. Starker; Kunstman, John W.; Prasad, Manju L.; Hartung, Erum A.; Mauras, Nelly; Benson, Matthew R.; Brady, Tammy

    2013-01-01

    Adrenal aldosterone-producing adenomas (APAs) constitutively produce the salt-retaining hormone aldosterone and are a common cause of severe hypertension. Recurrent mutations in the potassium channel KCNJ5 that result in cell depolarization and Ca2+ influx cause ~40% of these tumors 1 . We found five somatic mutations (four altering glycine 403, one altering isoleucine 770) in CACNA1D, encoding a voltage-gated calcium channel, among 43 non-KCNJ5-mutant APAs. These mutations lie in S6 segments...

  19. Activation of CFTR-mediated Cl- Transport by Magnolin

    Institute of Scientific and Technical Information of China (English)

    JIN Ling-ling; LIU Xin; SUN Yan; LIN Sen; ZHOU Na; XU Li-na; YU BO; HOU Shu-guang; YANG Hong

    2008-01-01

    Magnolin is a herbal compound from Magnolia biondii Pamp.It possesses numerous biological activities.Cystic fibrosis transmembrane conductance regulator(CFTR)is all epithelial chloride channel that plays a key role in the fluid secretion of various exocrine organs.In the present study,the activation of CFTR-mediated chloride transport by magnolin is indentified and characterized.In CFTR stably trailsfected FRT cells.magnolin increases CFTR Cl- currents in a concentration-dependent manner.The activation of magnolin on CFTR is rapid,reversible,and cAMP-dependent.Magnolin does not elevate cellular cAMP level.indicating that it activates CFTR by direct binding and interaction with CFTR protein.Magnolin selectively activates wildtype CFTR rather than mutant CFTIL Magnolin may present a novel class of therapeutic lead compound for the treatment of diseases associated with reduced CFTR function such as keratoconjunctivitis sicca,idiopathic chronic pancreatiti,and chromc constipation.

  20. Dexamethasone-responsive hypertension in young women with suppressed renin and aldosterone

    International Nuclear Information System (INIS)

    Pronounced hypoaldosteronism was found in three young women with hypertension and symptoms of mineralocorticoid overproduction - i.e., hyporeninaemia, hypokalaemia, and a fall in blood-pressure after diuretic therapy. Plasma 11-deoxycorticosterone and 18-hydroxy-11-deoxycorticosterone concentrations were normal. Treatment with dexamethasone induced a return to normal of blood-pressure and plasma-potassium and an increase in plasma-renin activity and urinary aldosterone excretion. The data suggest that hypertension in these patients is maintained by overproduction of an unknown adrenocorticotropin-dependent mineralocortocoid. (author)

  1. Somatic mutations in ATP1A1 and ATP2B3 lead to aldosterone-producing adenomas and secondary hypertension

    DEFF Research Database (Denmark)

    Beuschlein, Felix; Boulkroun, Sheerazed; Osswald, Andrea;

    2013-01-01

    Primary aldosteronism is the most prevalent form of secondary hypertension. To explore molecular mechanisms of autonomous aldosterone secretion, we performed exome sequencing of aldosterone-producing adenomas (APAs). We identified somatic hotspot mutations in the ATP1A1 (encoding an Na+/K+ ATPase α...... subunit) and ATP2B3 (encoding a Ca2+ ATPase) genes in three and two of the nine APAs, respectively. These ATPases are expressed in adrenal cells and control sodium, potassium and calcium ion homeostasis. Functional in vitro studies of ATP1A1 mutants showed loss of pump activity and strongly reduced...... affinity for potassium. Electrophysiological ex vivo studies on primary adrenal adenoma cells provided further evidence for inappropriate depolarization of cells with ATPase alterations. In a collection of 308 APAs, we found 16 (5.2%) somatic mutations in ATP1A1 and 5 (1.6%) in ATP2B3. Mutation...

  2. 21 CFR 862.1045 - Aldosterone test system.

    Science.gov (United States)

    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 §...

  3. The renaissance of primary aldosteronism: what has it taught us?

    Science.gov (United States)

    Stowasser, Michael; Gordon, Richard Douglas

    2013-06-01

    The growing realisation since the early 1990s that primary aldosteronism (PA) is a much more common cause of hypertension than previously thought, and that aldosterone excess has adverse effects that are at least partly independent of blood pressure, has been the main driving force for a renaissance in clinical and research interest in PA. This has generated a wealth of new knowledge regarding (1) PA's high prevalence, (2) the extent of non-BP dependent cardiovascular and renal organ damage and morbidity and reduced quality of life associated with PA, all of which appear to be at least partly ameliorated by specific treatment (especially surgical) directed against excessive aldosterone action, (3) the diversity of adrenal histopathology associated with PA and the need to subdivide patients based on glucocorticoid remediability (by genetic testing for the hybrid gene mutation causing familial hyperaldosteronism type I, FH-I) and lateralisation on adrenal venous sampling in order to ensure optimal treatment, (4) the value of elucidating genetic bases for PA in terms of improving detection, understanding of pathogenesis and treatment, as illustrated by the determination of the genetic basis of FH-I, and (5) the genetic basis of more common forms including aldosterone-producing adenoma. From the clinical perspective, the principal lesson learnt is that PA, being a common cause of cardiovascular morbidity and reduced quality of life reversible by specific treatment, is worth looking for. PMID:23402683

  4. Development and application of a simple radioimmunoassay for urinary aldosterone

    International Nuclear Information System (INIS)

    A simple, economical and direct assay was developed to measure aldosterone in urine, using aldosterone antibody of high specificity and gamma labelled ligand. The assay allows the direct measurement of aldosterone in 100 μl aliquots of urine after acid hydrolysis. It does not require preliminary solvent extraction and purification steps and hence a large number of samples in a single batch can be assayed simultaneously. An excellent correlation was obtained between the results of the direct assay and the levels measured after extraction and paper chromatography (Y=0.97X+0.89, r=0.99, p<0.001) or after extraction alone (Y=0.98X+1.75, r=0.99, p<0.001). The coefficients of variation for inter-assay and intra-assay determinations of samples from normal and high urine pools were 4.2-6.5% and 5.6-9.8%, respectively. Total urinary aldosterone excretion in 21 normal subjects on unrestricted sodium diet ranged from 3.8-20.2 μg/24h (10.5-55.0 nmol/24h) with a mean of 12.5 + - 4.6 (SD) μg/24h (34.7 +- 12.8 (SD) nmol/24h). (Auth.)

  5. SFE/SFHTA/AFCE primary aldosteronism consensus: Introduction and handbook.

    Science.gov (United States)

    Amar, Laurence; Baguet, Jean Philippe; Bardet, Stéphane; Chaffanjon, Philippe; Chamontin, Bernard; Douillard, Claire; Durieux, Pierre; Girerd, Xaxier; Gosse, Philippe; Hernigou, Anne; Herpin, Daniel; Houillier, Pascal; Jeunemaitre, Xavier; Joffre, Francis; Kraimps, Jean-Louis; Lefebvre, Hervé; Ménégaux, Fabrice; Mounier-Véhier, Claire; Nussberger, Juerg; Pagny, Jean-Yves; Pechère, Antoinette; Plouin, Pierre-François; Reznik, Yves; Steichen, Olivier; Tabarin, Antoine; Zennaro, Maria-Christina; Zinzindohoue, Franck; Chabre, Olivier

    2016-07-01

    The French Endocrinology Society (SFE) French Hypertension Society (SFHTA) and Francophone Endocrine Surgery Association (AFCE) have drawn up recommendations for the management of primary aldosteronism (PA), based on an analysis of the literature by 27 experts in 7 work-groups. PA is suspected in case of hypertension associated with one of the following characteristics: severity, resistance, associated hypokalemia, disproportionate target organ lesions, or adrenal incidentaloma with hypertension or hypokalemia. Diagnosis is founded on aldosterone/renin ratio (ARR) measured under standardized conditions. Diagnostic thresholds are expressed according to the measurement units employed. Diagnosis is established for suprathreshold ARR associated with aldosterone concentrations >550pmol/L (200pg/mL) on 2 measurements, and rejected for aldosterone concentrationhistory. The patient should be informed of the results expected from medical and surgical treatment of PA before exploration for lateralization is proposed. Lateralization is explored by adrenal vein sampling (AVS), except in patients under 35 years of age with unilateral adenoma on imaging. If PA proves to be lateralized, unilateral adrenalectomy may be performed, with adaptation of medical treatment pre- and postoperatively. If PA is non-lateralized or the patient refuses surgery, spironolactone is administered as first-line treatment, replaced by amiloride, eplerenone or calcium-channel blockers if insufficiently effective or poorly tolerated. PMID:27315757

  6. 15 CFR 930.44 - Availability of mediation for disputes concerning proposed activities.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Availability of mediation for disputes... PROGRAMS Consistency for Federal Agency Activities § 930.44 Availability of mediation for disputes..., either party may request the Secretarial mediation or OCRM mediation services provided for in subpart G....

  7. 15 CFR 930.45 - Availability of mediation for previously reviewed activities.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Availability of mediation for... PROGRAMS Consistency for Federal Agency Activities § 930.45 Availability of mediation for previously..., either party may request the Secretarial mediation or OCRM mediation services provided for in subpart...

  8. LIF Mediates Proinvasive Activation of Stromal Fibroblasts in Cancer

    Directory of Open Access Journals (Sweden)

    Jean Albrengues

    2014-06-01

    Full Text Available Signaling crosstalk between tumor cells and fibroblasts confers proinvasive properties to the tumor microenvironment. Here, we identify leukemia inhibitory factor (LIF as a tumor promoter that mediates proinvasive activation of stromal fibroblasts independent of alpha-smooth muscle actin (α-SMA expression. We demonstrate that a pulse of transforming growth factor β (TGF-β establishes stable proinvasive fibroblast activation by inducing LIF production in both fibroblasts and tumor cells. In fibroblasts, LIF mediates TGF-β-dependent actomyosin contractility and extracellular matrix remodeling, which results in collective carcinoma cell invasion in vitro and in vivo. Accordingly, carcinomas from multiple origins and melanomas display strong LIF upregulation, which correlates with dense collagen fiber organization, cancer cell collective invasion, and poor clinical outcome. Blockade of JAK activity by Ruxolitinib (JAK inhibitor counteracts fibroblast-dependent carcinoma cell invasion in vitro and in vivo. These findings establish LIF as a proinvasive fibroblast producer independent of α-SMA and may open novel therapeutic perspectives for patients with aggressive primary tumors.

  9. Functional analysis of Ficolin-3 mediated complement activation

    DEFF Research Database (Denmark)

    Hein, Estrid; Honoré, Christian Le Fèvre; Skjoedt, Mikkel-Ole;

    2010-01-01

    assessed by C4, C3 and terminal complement complex (TCC) deposition. Serum Ficolin-3 bound to acBSA in a calcium dependent manner, while only minimal binding of Ficolin-2 and no binding of Ficolin-1 were observed. No binding to normal BSA was seen for any of the Ficolins. Serum C4, C3 and TCC deposition on...... applied to the samples that inhibited interference from the classical pathway due to the presence of anti-BSA antibodies in some sera. We describe a novel functional method for measuring complement activation mediated by Ficolin-3 in human serum up to the formation of TCC. The assay provides the...

  10. Serum inflammatory mediators as markers of human Lyme disease activity.

    Directory of Open Access Journals (Sweden)

    Mark J Soloski

    Full Text Available Chemokines and cytokines are key signaling molecules that orchestrate the trafficking of immune cells, direct them to sites of tissue injury and inflammation and modulate their states of activation and effector cell function. We have measured, using a multiplex-based approach, the levels of 58 immune mediators and 7 acute phase markers in sera derived from of a cohort of patients diagnosed with acute Lyme disease and matched controls. This analysis identified a cytokine signature associated with the early stages of infection and allowed us to identify two subsets (mediator-high and mediator-low of acute Lyme patients with distinct cytokine signatures that also differed significantly (p<0.0005 in symptom presentation. In particular, the T cell chemokines CXCL9 (MIG, CXCL10 (IP-10 and CCL19 (MIP3B were coordinately increased in the mediator-high group and levels of these chemokines could be associated with seroconversion status and elevated liver function tests (p = 0.027 and p = 0.021 respectively. There was also upregulation of acute phase proteins including CRP and serum amyloid A. Consistent with the role of CXCL9/CXCL10 in attracting immune cells to the site of infection, CXCR3+ CD4 T cells are reduced in the blood of early acute Lyme disease (p = 0.01 and the decrease correlates with chemokine levels (p = 0.0375. The levels of CXCL9/10 did not relate to the size or number of skin lesions but elevated levels of serum CXCL9/CXCL10 were associated with elevated liver enzymes levels. Collectively these results indicate that the levels of serum chemokines and the levels of expression of their respective chemokine receptors on T cell subsets may prove to be informative biomarkers for Lyme disease and related to specific disease manifestations.

  11. Environmental phthalate monoesters activate pregnane X receptor-mediated transcription

    International Nuclear Information System (INIS)

    Phthalate esters, widely used as plasticizers in the manufacture of products made of polyvinyl chloride, induce reproductive and developmental toxicities in rodents. The mechanism that underlies these effects of phthalate exposure, including the potential role of members of the nuclear receptor superfamily, is not known. The present study investigates the effects of phthalates on the pregnane X receptor (PXR), which mediates the induction of enzymes involved in steroid metabolism and xenobiotic detoxification. The ability of phthalate monoesters to activate PXR-mediated transcription was assayed in a HepG2 cell reporter assay following transfection with mouse PXR (mPXR), human PXR (hPXR), or the hPXR allelic variants V140M, D163G, and A370T. Mono-2-ethylhexyl phthalate (MEHP) increased the transcriptional activity of both mPXR and hPXR (5- and 15-fold, respectively) with EC50 values of 7-8 μM. mPXR and hPXR were also activated by monobenzyl phthalate (MBzP, up to 5- to 6-fold) but were unresponsive to monomethyl phthalate and mono-n-butyl phthalate (M(n)BP) at the highest concentrations tested (300 μM). hPXR-V140M and hPXR-A370T exhibited patterns of phthalate responses similar to the wild-type receptor. By contrast, hPXR-D163G was unresponsive to all phthalate monoesters tested. Further studies revealed that hPXR-D163G did respond to rifampicin, but required approximately 40-fold higher concentrations than wild-type receptor, suggesting that the ligand-binding domain D163G variant has impaired ligand-binding activity. The responsiveness of PXR to activation by phthalate monoesters demonstrated here suggests that these ubiquitous environmental chemicals may, in part, exhibit their endocrine disruptor activities by altering PXR-regulated steroid hormone metabolism with potential adverse health effects in exposed individuals

  12. Biosensor cell assay for measuring real-time aldosterone-induced release of histamine from mesenteric arteries

    DEFF Research Database (Denmark)

    Dalgaard, Emil G; Andersen, Kenneth; Svenningsen, Per; Hansen, Pernille B L

    2016-01-01

    AIMS: The aims were to develop a method for real-time detection of histamine release and to test if incubation with aldosterone induces histamine release from isolated, perfused mice mesenteric arteries. METHODS: Fura-2 loaded HEK-293 cells transfected with the histamine H1 receptor was used as a...... sensitive biosensor assay for histamine release from isolated mouse mesenteric arteries. Activation of the H1 receptor by histamine was measured as an increased number of intracellular Ca(2+) transient peaks using fluorescence imaging RESULTS: The developed biosensor was sensitive to histamine in...... physiological relevant concentrations and responded to substances released by the artery preparation. Aldosterone treatment of mesenteric arteries from wild type mice for 50 minutes resulted in an increased number of intracellular Ca(2+) transient peaks in the biosensor cells, which was significantly inhibited...

  13. Similar to spironolactone, oxymatrine is protective in aldosterone-induced cardiomyocyte injury via inhibition of calpain and apoptosis-inducing factor signaling.

    Directory of Open Access Journals (Sweden)

    Ting-Ting Xiao

    Full Text Available Accumulating evidence indicates that oxymatrine (OMT possesses variously pharmacological properties, especially on the cardiovascular system. We previously demonstrated that activated calpain/apoptosis-inducing factor (AIF-mediated pathway was the key molecular mechanism in aldosterone (ALD induces cardiomyocytes apoptosis. In the present study, we extended the experimentation by investigating the effect of OMT on cardiomyocytes exposed to ALD, as compared to spironolactone (Spiro, a classical ALD receptor antagonist. Cardiomyocytes were pre-incubated with OMT, Spiro or vehicle for 1 h, and then, cardiomyocytes were exposed to ALD 24 h. The cell injury was evaluated by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay and lactate dehydrogenase (LDH leakage ratio. Apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL assay, annexin V/PI staining, and relative caspase-3 activity assay. Furthermore, expression of pro-apoptotic proteins including truncated Bid (tBid, calpain and AIF were evaluated by western blot analysis. ALD stimulation increased cardiomyocytes apoptosis, caspase-3 activity and protein expression of calpain, tBid and AIF in the cytosol (p<0.05. Pre-incubated with cardiomyocytes injury and increased caspase-3 activity were significantly attenuated (p<0.05. Furthermore, OMT suppressed ALD-induced high expression of calpain and AIF. And these effects of OMT could be comparable to Spiro. These findings indicated that OMT might be a potential cardioprotective-agent against excessive ALD-induced cardiotoxicity, at least in part, mediated through inhibition of calpain/AIF signaling.

  14. Renin-angiotensin-aldosterone responsiveness to low sodium and blood pressure reactivity to angiotensin-II are unrelated to cholesteryl ester transfer protein mass in healthy subjects

    NARCIS (Netherlands)

    Krikken, Jan A.; Dallinga-Thie, Geesje M.; Navis, Gerjan; Dullaart, Robin P. F.

    2008-01-01

    Background: The blood pressure increase associated with the cholesteryl ester transfer protein (CETP) inhibitor, torcetrapib is probably attributable to an off-target effect but it is unknown whether activation of the renin-angiotensin-aldosterone system (RAAS) may be related to variation in the pla

  15. High prevalence of thyroid ultrasonographic abnormalities in primary aldosteronism.

    Science.gov (United States)

    Armanini, Decio; Nacamulli, Davide; Scaroni, Carla; Lumachi, Franco; Selice, Riccardo; Fiore, Cristina; Favia, Gennaro; Mantero, Franco

    2003-11-01

    The study was performed to evaluate the prevalence of thyroid abnormalities detected by ultrasonography and, in particular, of multinodular nontoxic goiter in primary aldosteronism. We analyzed 80 consecutive of patients with primary hyperaldosteronism (40 with unilateral adenoma and 40 with idiopathic hyperaldosteronism) and 80 normotensive healthy controls, comparable for age, sex, iodine intake, and geographical area. Blood pressure, thyroid palpation, thyroid function, and ultrasonography were evaluated. The prevalence of ultrasonographic thyroid abnormalities was 60% in primary aldosteronism and 27% in controls (p < 0.0001). There was a statistically significant difference in prevalence of these abnormalities in unilateral adenoma and idiopathic hyperaldosteronism with respect to controls (p < 0.05 and p < 0.0001, respectively). The prevalence of multinodular nontoxic goiter in idiopathic hyperaldosteronism was higher than in controls (p < 0.001) and, in particular, in female patients. From these data it seems to be worth considering the existence of primary hyperaldosteronism in patients with multinodular goiter and hypertension. PMID:14665720

  16. Renin and aldosterone measurements in the management of arterial hypertension.

    Science.gov (United States)

    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. PMID:25993253

  17. Adrenal vein sampling in primary aldosteronism: towards a standardised protocol.

    Science.gov (United States)

    Monticone, Silvia; Viola, Andrea; Rossato, Denis; Veglio, Franco; Reincke, Martin; Gomez-Sanchez, Celso; Mulatero, Paolo

    2015-04-01

    Primary aldosteronism comprises subtypes that need different therapeutic strategies. Adrenal vein sampling is recognised by Endocrine Society guidelines as the only reliable way to correctly diagnose the subtype of primary aldosteronism. Unfortunately, despite being the gold-standard procedure, no standardised procedure exists either in terms of performance or interpretation criteria. In this Personal View, we address several questions that clinicians are presented with when considering adrenal vein sampling. For each of these questions we provide responses based on the available evidence, and opinions based on our experience. In particular, we discuss the most appropriate way to prepare the patient, whether adrenal vein sampling can be avoided for some subgroups of patients, the use of ACTH (1-24) during the procedure, the most appropriate criteria for interpretation of adrenal vein cannulation and lateralisation, the use of contralateral suppression, and strategies to improve success rates of adrenal vein sampling in centres with little experience. PMID:24831990

  18. A Rare Presentation of Primary Hyperparathyroidism with Concurrent Aldosterone-Producing Adrenal Carcinoma

    Directory of Open Access Journals (Sweden)

    Mario Molina-Ayala

    2015-01-01

    Full Text Available Aldosterone-producing adrenocortical carcinomas are an extremely rare cause of hyperaldosteronism (<1%. Coexistence of different endocrine tumors warrants additional screening for multiple endocrine neoplasia syndromes, especially in young patients with large or malignant masses. We present the case of a 40-year-old man with a history of hypertension that presented with an incidental left adrenal tumor during an ultrasound performed for nephrolithiasis. Biochemical assessment showed a mildly elevated calcium (11.1 mg/dL, high parathyroid hormone, and a plasma aldosterone concentration/plasma renin activity ratio of 124.5 (normal < 30, compatible with primary hyperparathyroidism with a concomitant primary hyperaldosteronism. A Tc99m-MIBI scintigraphy showed an abnormally increased tracer uptake in the right superior parathyroid and abdominal computed tomography confirmed a left adrenal tumor of 20 cm. The patient underwent parathyroidectomy and adrenalectomy with final pathology reports of parathyroid hyperplasia and adrenal carcinoma with biochemical remission of both endocrinopathies. He was started on chemotherapy, but the patient developed a frontal cortex and an arm metastasis and finally died less than one year later.

  19. Comparison of eplerenone and spironolactone for the treatment of primary aldosteronism.

    Science.gov (United States)

    Karashima, Shigehiro; Yoneda, Takashi; Kometani, Mitsuhiro; Ohe, Masashi; Mori, Shunsuke; Sawamura, Toshitaka; Furukawa, Kenji; Seta, Takashi; Yamagishi, Masakazu; Takeda, Yoshiyu

    2016-03-01

    The mineralocorticoid receptor (MR) is expressed in the kidneys and in adipose tissue, and primary aldosteronism (PA) is associated with metabolic syndrome. This study assessed the effects of MR blockade by eplerenone (EPL) and spironolactone (SPL) on blood pressure (BP) and metabolic factors in patients with PA. Fifty-four patients with PA were treated with one of two MRAs, EPL (25-100 mg daily, n=27) or SPL (12.5-100 mg daily, n=27) for 12 months. Visceral (VAT) and subcutaneous adipose tissue were quantified using CT and FatScan imaging analysis software. Body mass index, homeostasis model assessment-insulin resistance (HOMA-IR), serum creatinine, potassium and lipids, urinary albumin excretion (UAE) and plasma aldosterone concentration (PAC) and plasma renin activity (PRA) were measured before and after treatment. EPL and SPL decreased BP and increased serum potassium levels to similar degrees. PAC and PRA did not differ between the two groups. Although treatment with the MRAs did not change HOMA-IR or serum lipids, they significantly decreased UAE and VAT (PEPL and SPL are effective and safe for the treatment of PA. The long-term metabolic and renal effects of these MRAs should be further investigated. PMID:26606875

  20. Overview of the genetic determinants of primary aldosteronism

    Science.gov (United States)

    Al-Salameh, Abdallah; Cohen, Régis; Desailloud, Rachel

    2014-01-01

    Primary aldosteronism is the most common cause of secondary hypertension. The syndrome accounts for 10% of all cases of hypertension and is primarily caused by bilateral adrenal hyperplasia or aldosterone-producing adenoma. Over the last few years, the use of exome sequencing has significantly improved our understanding of this syndrome. Somatic mutations in the KCNJ5, ATP1A1, ATP2B3 or CACNA1D genes are present in more than half of all cases of aldosterone-producing adenoma (~40%, ~6%, ~1% and ~8%, respectively). Germline gain-of-function mutations in KCNJ5 are now known to cause familial hyperaldosteronism type III, and an additional form of genetic hyperaldosteronism has been reported in patients with germline mutations in CACNA1D. These genes code for channels that control ion homeostasis across the plasma membrane of zona glomerulosa cells. Moreover, all these mutations modulate the same pathway, in which elevated intracellular calcium levels lead to aldosterone hyperproduction and (in some cases) adrenal cell proliferation. From a clinical standpoint, the discovery of these mutations has potential implications for patient management. The mutated channels could be targeted by drugs, in order to control hormonal and overgrowth-related manifestations. Furthermore, some of these mutations are associated with high cell turnover and may be amenable to diagnosis via the sequencing of cell-free (circulating) DNA. However, genotype-phenotype correlations in patients harboring these mutations have yet to be characterized. Despite this recent progress, much remains to be done to elucidate the yet unknown mechanisms underlying sporadic bilateral adrenal hyperplasia. PMID:24817817

  1. Physiological techniques in the study of rapid aldosterone effects.

    Science.gov (United States)

    Yusef, Yamil R; Thomas, Warren; Harvey, Brian J

    2014-01-01

    Molecular imaging and electrophysiological techniques are powerful tools to analyze the responses stimulated by aldosterone and other hormones in target tissues. Studies with Ussing-type chambers can be used to measure and characterize changes in transepithelial currents resulting from hormone treatment. Confocal imaging techniques can be used in real time or in fixed preparations to evaluate the localization of receptors, signalling intermediates, and transporters. PMID:25182774

  2. Emergence and evolution of the renin-angiotensin-aldosterone system

    OpenAIRE

    Fournier, D.; Luft, F C; Bader, M.; Ganten, D; Andrade-Navarro, M A

    2012-01-01

    The renin–angiotensin–aldosterone system (RAAS) is not the sole, but perhaps the most important volume regulator in vertebrates. To gain insights into the function and evolution of its components, we conducted a phylogenetic analysis of its main related genes. We found that important parts of the system began to appear with primitive chordates and tunicates and that all major components were present at the divergence of bony fish, with the exception of the Mas receptor. The Mas receptor first...

  3. Effect of Eplerenone, a Selective Aldosterone Blocker, on the Development of Diabetic Nephropathy in Type 2 Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Jae Hee Ahn

    2012-04-01

    Full Text Available BackgroundAldosterone antagonists are reported to have beneficial effects on diabetic nephropathy by effective blocking of the renin-angiotensin-aldosterone system. We investigated the renoprotective effect of the selective aldosterone receptor blocker eplerenone, the angiotensin converting enzyme inhibitor lisinopril, and combined eplerenone and lisinopril treatment in type 2 diabetic rats.MethodsAnimals were divided into six groups as follows: Otsuka Long-Evans Tokushima Fatty (OLETF rat control, OLETF rats treated with a low dose of eplerenone (50 mg/kg/day, OLETF rats treated with a high dose of eplerenone (200 mg/kg/day, OLETF rats treated with lisinopril (10 mg/kg/day, OLETF rats treated with a combination of both drugs (eplerenone 200 mg/kg/day and lisinopril 10 mg/kg/day, and obese non-diabetic Long-Evans Tokushima Otsuka rats for 26 weeks.ResultsUrinary albumin excretion was significantly lower in the lisinopril group, but not in the eplerenone group. Urinary albumin excretion was decreased in the combination group than in the lisinopril group. Glomerulosclerosis and renal expression of type I and type IV collagen, plasminogen activator inhibitor-1, transforming growth factor-β1, connective tissue growth factor, and fibronectin mRNA were markedly decreased in the lisinopril, eplerenone, and combination groups.ConclusionEplerenone and lisinopril combination showed additional benefits on type 2 diabetic nephropathy compared to monotherapy of each drug.

  4. Cortisol and aldosterone comparisons of cottontail rabbits collected by shooting, trapping, and falconry.

    Science.gov (United States)

    Hamilton, G D; Weeks, H P

    1985-01-01

    Cortisol and aldosterone levels were measured in plasma of eastern cottontail rabbits (Sylvilagus floridanus) collected by three different methods, i.e., shooting, live-trapping and falconry. Cortisol levels ranged from near 0 to 27.5 micrograms/100 ml and aldosterone from near 0 to 220 ng/100 ml. Shot animals had significantly lower cortisol concentrations than those taken by either of the other methods. Trapped cottontails also had significantly lower aldosterone levels. PMID:3981742

  5. Die Rolle von growth arrest specific protein 6 im Aldosteron induzierten Endorganschaden

    OpenAIRE

    Theuer, Stefanie

    2013-01-01

    Growth arrest specific protein 6 (Gas 6) is involved in inflammatory kidney diseases, vascular remodeling, cell adhesion, and thrombus formation. We explored a role for Gas 6 in aldosterone-induced target organ damage. We observed that Gas 6 was upregulated in rats with high aldosterone levels. Mineralocorticoid receptor blockade prevented target organ damage and decreased the elevated Gas 6 expression. Vascular smooth muscle cells given aldosterone increased their Gas 6 expression in vitro. ...

  6. Bactericidal activity of metal-mediated peroxide-ascorbate systems.

    Science.gov (United States)

    Drath, D B; Karnovsky, M L

    1974-11-01

    Model systems containing ascorbate, hydrogen peroxide, and divalent copper or cobalt have been shown to possess marked bactericidal activity. At equivalent concentrations, copper-containing systems were more bactericidal than the corresponding mixtures containing cobalt. Cobalt at concentrations below 10(-4) M did not appreciably augment microbicidal activity, whereas systems containing copper at concentrations as low as 5 x 10(-6) M were still capable of causing some bacterial death. Manganese was inactive. None of these systems was as potent as the well known myeloperoxidase-peroxide-halide system. The mechanisms of action of these systems are not as yet clear. The possibility that they function through the generation of superoxide (O(2) (-)), hydroxyl radical (OH.), or other free radicals was explored through the use of superoxide dismutase and several free radical scavengers. It seems likely at present that the two active metal-mediated systems function via separate mechanisms. The copper system acts with dehydroascorbate, whereas the cobalt system does not. Activity in the cobalt system appears to depend upon the generation of free radicals. PMID:16558093

  7. Dihydrobenzofuran Neolignanamides: Laccase-Mediated Biomimetic Synthesis and Antiproliferative Activity.

    Science.gov (United States)

    Cardullo, Nunzio; Pulvirenti, Luana; Spatafora, Carmela; Musso, Nicolò; Barresi, Vincenza; Condorelli, Daniele Filippo; Tringali, Corrado

    2016-08-26

    The biomimetic synthesis of a small library of dihydrobenzofuran neolignanamides (the natural trans-grossamide (4) and the related compounds 21-28) has been carried out through an eco-friendly oxidative coupling reaction mediated by Trametes versicolor laccase. These products, after complete spectroscopic characterization, were evaluated for their antiproliferative activity against Caco-2 (colon carcinoma), MCF-7 (mammary adenocarcinoma), and PC-3 (prostate cancer) human cells, using an MTT bioassay. The racemic neolignamides (±)-21 and (±)-27, in being the most lipophilic in the series, were potently active, with GI50 values comparable to or even lower than that of the positive control 5-FU. The racemates were resolved through chiral HPLC, and the pure enantiomers were subjected to ECD measurements to establish their absolute configurations at C-2 and C-3. All enantiomers showed potent antiproliferative activity, with, in particular, a GI50 value of 1.1 μM obtained for (2R,3R)-21. The effect of (±)-21 on the Caco-2 cell cycle was evaluated by flow cytometry, and it was demonstrated that (±)-21 exerts its antiproliferative activity by inducing cell cycle arrest and apoptosis. PMID:27504537

  8. Biological determinants of aldosterone-induced cardiac fibrosis in rats.

    Science.gov (United States)

    Robert, V; Silvestre, J S; Charlemagne, D; Sabri, A; Trouvé, P; Wassef, M; Swynghedauw, B; Delcayre, C

    1995-12-01

    To determine the events leading to cardiac fibrosis in aldosterone-salt hypertensive rats, we studied protein and mRNA accumulation of procollagens I and III for 60 days. After 3 and 7 days of treatment systolic pressure was normal, and no histological or biochemical changes were seen in rat hearts. At day 15 arterial pressure was raised (+40%) and left ventricular hypertrophy was +15%. Cardiac examination after hemalun-eosin staining and immunolabeling with anticollagen I and III antibodies showed no structural alterations, but an 83% increase in right ventricular type III procollagen mRNA levels was found. At 30 and 60 days we found progressive cardiac fibrosis, with inflammatory cells, myocyte necrosis, and elevation of both types I and III procollagen mRNA levels in both ventricles. To determine whether aldosterone had effects on Na,K-ATPase that might lead to ionic disturbances and induce myocyte necrosis, we studied the major cardiac Na,K-ATPase isoform genes. Although Na,K-ATPase alpha 1- and beta 1-subunit mRNA levels were elevated in kidney at day 1, neither of these cardiac transcripts nor the specific alpha 2 isoform was altered between 1 and 15 days. These results show that accumulation of procollagen mRNAs occurs before collagen deposition. Cardiac alterations are late and not preceded by changes in Na,K-ATPase cardiac gene expression, precluding a direct modulation of cardiac collagen synthesis and Na,K-ATPase by aldosterone. PMID:7490157

  9. Upregulation of the Renin-Angiotensin-Aldosterone-Ouabain System in the Brain Is the Core Mechanism in the Genesis of All Types of Hypertension

    Directory of Open Access Journals (Sweden)

    Hakuo Takahashi

    2012-01-01

    Full Text Available Basic research using animal models points to a causal role of the central nervous system in essential hypertension; however, since clinical research is technically difficult to perform, this connection has not been confirmed in humans. Recently, renal nerve ablation in humans proved to continuously decrease blood pressure in resistant hypertension. Furthermore, when electrical stimulation was continuously applied to the carotid baroreceptor nerve of human adults, their blood pressure lowered. These findings promoted the concept that the central nervous system may actually be involved in the pathogenesis of essential hypertension, which is closely associated with excess sodium intake. We have demonstrated that endogenous digitalis plays a key role in hypertension associated with excess sodium intake via sympathetic activation in rats. Increased sodium concentration inside the brain activates epithelial sodium channels and the renin-angiotensin-aldosterone system in the brain. Aldosterone releases ouabain from neurons in the paraventricular nucleus in the hypothalamus. Angiotensin II and aldosterone of peripheral origin reach the brain to augment sympathetic outflow. Collectively essential hypertension associated with excess sodium intake and obesity, renovascular hypertension, and primary aldosteronism and pseudoaldosteronism all seem to have a common cause originating from the central nervous system.

  10. Does the aldosterone: renin ratio predict the efficacy of spironolactone over bendroflumethiazide in hypertension? A clinical trial protocol for RENALDO (RENin-ALDOsterone study

    Directory of Open Access Journals (Sweden)

    McInnes Gordon T

    2007-05-01

    Full Text Available Abstract Background High blood pressure is an important determinant of cardiovascular disease risk. Treated hypertensives do not attain a risk level equivalent to normotensives. This may be a consequence of suboptimal blood pressure control to which indiscriminate use of antihypertensive drugs may contribute. Indeed the recent ALLHAT1study suggests that thiazides should be given first to virtually all hypertensives. Whether this is correct or whether different antihypertensive therapies should be targeted towards different patients is a major unresolved issue, which we address in this study. The measurement of the ratio of aldosterone: renin is used to identify hypertensive subjects who may respond well to treatment with the aldosterone antagonist spironolactone. It is not known if subjects with a high ratio have aldosteronism or aldosterone-sensitive hypertension is debated but it is important to know whether spironolactone is superior to other diuretics such as bendroflumethiazide in this setting. Methods/design The study is a double-blind, randomised, crossover, controlled trial that will randomise 120 hypertensive subjects to 12 weeks treatment with spironolactone 50 mg once daily and 12 weeks treatment with bendroflumethiazide 2.5 mg once daily. The 2 treatment periods are separated by a 2-week washout period. Randomisation is stratified by aldosterone: renin ratio to include equal numbers of subjects with high and low aldosterone: renin ratios. Primary Objective – To test the hypothesis that the aldosterone: renin ratio predicts the antihypertensive response to spironolactone, specifically that the effect of spironolactone 50 mg is greater than that of bendroflumethiazide 2.5 mg in hypertensive subjects with high aldosterone: renin ratios. Secondary Objectives – To determine whether bendroflumethiazide induces adverse metabolic abnormalities, especially in subjects with high aldosterone: renin ratios and if baseline renin measurement

  11. MITOCHONDRIAL REACTIVE OXYGEN SPECIES (ROS AS SIGNALLING MOLECULES OF INTRACELLULAR PATHWAYS TRIGGERED BY THE CARDIAC RENIN-ANGIOTENSIN II-ALDOSTERONE SYSTEM (RAAS.

    Directory of Open Access Journals (Sweden)

    Verónica Celeste De Giusti

    2013-05-01

    Full Text Available Mitochondria represent major sources of basal reactive oxygen species (ROS production of the cardiomyocyte. The role of ROS as signalling molecules that mediate different intracellular pathways has gained increasing interest among physiologists in the last years. In our lab, we have been studying the participation of mitochondrial ROS in the intracellular pathways triggered by the renin-angiotensin II-aldosterone system (RAAS in the myocardium during the past few years. We have demonstrated that acute activation of cardiac RAAS induces mitochondrial ATP-dependent potassium channel (mitoKATP opening with the consequent enhanced production of mitochondrial ROS. These oxidant molecules, in turn, activate membrane transporters, as sodium/hydrogen exchanger (NHE-1 and sodium/bicarbonate cotransporter (NBC via the stimulation of the ROS-sensitive MAPK cascade. The stimulation of such effectors leads to an increase in cardiac contractility. In addition, it is feasible to suggest that a sustained enhanced production of mitochondrial ROS induced by chronic cardiac RAAS, and hence, chronic NHE-1 and NBC stimulation, would also result in the development of cardiac hypertrophy.

  12. Wastewater Mediated Activation of Micromotors for Efficient Water Cleaning.

    Science.gov (United States)

    Srivastava, Sarvesh Kumar; Guix, Maria; Schmidt, Oliver G

    2016-01-13

    We present wastewater-mediated activation of catalytic micromotors for the degradation of nitroaromatic pollutants in water. These next-generation hybrid micromotors are fabricated by growing catalytically active Pd particles over thin-metal films (Ti/Fe/Cr), which are then rolled-up into self-propelled tubular microjets. Coupling of catalytically active Pd particles inside the micromotor surface in the presence of a 4-nitrophenol pollutant (with NaBH4 as reductant) results in autonomous motion via the bubble-recoil propulsion mechanism such that the target pollutant mixture (wastewater) is consumed as a fuel, thereby generating nontoxic byproducts. This study also offers several distinct advantages over its predecessors including no pH/temperature manipulation, limited stringent process control and complete destruction of the target pollutant mixture. The improved intermixing ability of the micromotors caused faster degradation ca. 10 times higher as compared to its nonmotile counterpart. The high catalytic efficiency obtained via a wet-lab approach has promising potential in creating hybrid micromotors comprising of multicatalytic systems assembled into one entity for sustainable environmental remediation and theranostics. PMID:26674098

  13. Retinoic Acid-mediated Nuclear Receptor Activation and Hepatocyte Proliferation

    Science.gov (United States)

    Bushue, Nathan; Wan, Yu-Jui Yvonne

    2016-01-01

    Due to their well-known differentiation and apoptosis-inducing abilities, retinoic acid (RA) and its analogs have strong anti-cancer efficacy in human cancers. However, in vivo RA is a liver mitogen. While speculation has persisted that RA-mediated signaling is likely involved in hepatocyte proliferation during liver regeneration, direct evidence is still required. Findings in support of this proposition include observations that a release of retinyl palmitate (the precursor of RA) occurs in liver stellate cells following liver injury. Nevertheless, the biological action of this released vitamin A is virtually unknown. More likely is that the released vitamin A is converted to RA, the biological form, and then bound to a specific receptor (retinoid x receptor; RXRα), which is most abundantly expressed in the liver. Considering the mitogenic effects of RA, the RA-activated RXRα would likely then influence hepatocyte proliferation and liver tissue repair. At present, the mechanism by which RA stimulates hepatocyte proliferation is largely unknown. This review summarizes the activation of nuclear receptors (peroxisome proliferator activated receptor-α, pregnane x receptor, constitutive androstane receptor, and farnesoid x receptor) in an RXRα dependent manner to induce hepatocyte proliferation, providing a link between RA and its proliferative role.

  14. Overview of the genetic determinants of primary aldosteronism

    Directory of Open Access Journals (Sweden)

    Al-Salameh A

    2014-04-01

    Full Text Available Abdallah Al-Salameh,1 Régis Cohen,2 Rachel Desailloud3 1Service de Diabétologie, Endocrinologie et Maladies Métaboliques, Centre Hospitalier de Creil, Creil, France; 2Service d'Endocrinologie, Centre Hospitalier de Saint-Denis, Saint-Denis, France; 3Service d'Endocrinologie, Diabétologie et Nutrition, Centre Hospitalier Universitaire d'Amiens, Amiens, France Abstract: Primary aldosteronism is the most common cause of secondary hypertension. The syndrome accounts for 10% of all cases of hypertension and is primarily caused by bilateral adrenal hyperplasia or aldosterone-producing adenoma. Over the last few years, the use of exome sequencing has significantly improved our understanding of this syndrome. Somatic mutations in the KCNJ5, ATP1A1, ATP2B3 or CACNA1D genes are present in more than half of all cases of aldosterone-producing adenoma (~40%, ~6%, ~1% and ~8%, respectively. Germline gain-of-function mutations in KCNJ5 are now known to cause familial hyperaldosteronism type III, and an additional form of genetic hyperaldosteronism has been reported in patients with germline mutations in CACNA1D. These genes code for channels that control ion homeostasis across the plasma membrane of zona glomerulosa cells. Moreover, all these mutations modulate the same pathway, in which elevated intracellular calcium levels lead to aldosterone hyperproduction and (in some cases adrenal cell proliferation. From a clinical standpoint, the discovery of these mutations has potential implications for patient management. The mutated channels could be targeted by drugs, in order to control hormonal and overgrowth-related manifestations. Furthermore, some of these mutations are associated with high cell turnover and may be amenable to diagnosis via the sequencing of cell-free (circulating DNA. However, genotype-phenotype correlations in patients harboring these mutations have yet to be characterized. Despite this recent progress, much remains to be done to

  15. Impact of leptin-mediated sympatho-activation on cardiovascular function in obese mice

    OpenAIRE

    Belin de Chantemèle, Eric J.; Mintz, James D.; Rainey, William E.; Stepp, David W.

    2011-01-01

    Although the anorexic effects of leptin are lost in obesity, leptin-mediated sympatho-activation is preserved. The cardiovascular consequences of leptin-mediated sympatho-activation in obesity are poorly understood. We tested the hypothesis that 32 weeks of high fat diet (HFD) induces metabolic leptin resistance but preserves leptin-mediated sympatho-activation of the cardiovascular system. HFD in mice significantly increased body weight and plasma leptin concentrations but significantly redu...

  16. Eosinophil recruitment and activation: the role of lipid mediators

    OpenAIRE

    Luna-Gomes, Tatiana; Bozza, Patrícia T.; Bandeira-Melo, Christianne

    2013-01-01

    Eosinophils are effector cells that migrate toward several mediators released at inflammatory sites to perform their multiple functions. The mechanisms driving eosinophil selective accumulation in sites of allergic inflammation are well-established and involve several steps controlled by adhesion molecules, priming agents, chemotactic, and surviving factors. Even though the majority of studies focused on role of protein mediators like IL-5 and eotaxins, lipid mediators also participate in eos...

  17. Lipopolysaccharide (LPS)-mediated macrophage activation: the role of calcium in the generation of tumoricidal activity

    Energy Technology Data Exchange (ETDEWEB)

    Drysdale, B.E.; Shin, H.S.

    1986-03-01

    As the authors reported, calcium ionophore, A23187, activates macrophages (M theta) for tumor cell killing and the activated M theta produce a soluble cytotoxic factor (M theta-CF) that is similar if not identical to tumor necrosis factor. Based on these observations they have investigated whether calcium is involved in the activation mediated by another potent M theta activator, LPS. The authors have shown that A23187 caused uptake of extracellular /sup 45/Ca/sup + +/ but LPS did not. They have examined the effect of depleting extracellular calcium by using medium containing no added calcium containing 1.0 mM EGTA. In no case did depletion result in decreased M theta-CF production by the M theta activated with LPS. Measurements using the fluorescent, intracellular calcium indicator, Quin 2 have also been performed. While ionomycin, caused a rapid change in the Quin-2 signal, LPS at a concentration even in excess of that required to activate the M theta caused no change in the signal. When high doses of Quin 2 or another intracellular chelator, 8-(diethylaminol-octyl-3,4,5-trimethoxybenzoate, were used to treat M theta, M theta-CF production decreased and cytotoxic activity was impaired. These data indicate that one or more of the processes involved in M theta-CF production does require calcium, but that activation mediated by LPS occurs without the influx of extracellular calcium or redistribution of intracellular calcium.

  18. Plasma-activated air mediates plasmid DNA delivery in vivo.

    Science.gov (United States)

    Edelblute, Chelsea M; Heller, Loree C; Malik, Muhammad A; Bulysheva, Anna; Heller, Richard

    2016-01-01

    Plasma-activated air (PAA) provides a noncontact DNA transfer platform. In the current study, PAA was used for the delivery of plasmid DNA in a 3D human skin model, as well as in vivo. Delivery of plasmid DNA encoding luciferase to recellularized dermal constructs was enhanced, resulting in a fourfold increase in luciferase expression over 120 hours compared to injection only (P plasmid DNA encoding green fluorescent protein (GFP) was confirmed in the epidermal layers of the construct. In vivo experiments were performed in BALB/c mice, with skin as the delivery target. PAA exposure significantly enhanced luciferase expression levels 460-fold in exposed sites compared to levels obtained from the injection of plasmid DNA alone (P plasmid DNA encoding GFP to mouse skin was confirmed by immunostaining, where a 3-minute exposure at a 10 mm distance displayed delivery distribution deep within the dermal layers compared to an exposure at 3 mm where GFP expression was localized within the epidermis. Our findings suggest PAA-mediated delivery warrants further exploration as an alternative approach for DNA transfer for skin targets. PMID:27110584

  19. Radioimmunoassay of aldosterone in adrenal venous effluent in a case of Conn's syndrome, ch. 5a

    International Nuclear Information System (INIS)

    In a case of Conn's syndrome samples were obtained from the venous effluent of both adrenals and from peripheral veins during venography. The aldosterone concentration was measured by means of radioimmunoassay. The sensitivty of the aldosterone assay was 27 pg (P<0.05), the parallelism between the standard and the serum dilutions was excellent and there was no cross-reaction with cortisol, cortisone, 21-desoxycortisol, dexamethasone or spironolactone in amounts up to 1 μg per incubation. The aldosterone concentrations measured in peripheral venous blood were 220-250 ng/100 ml serum. In the effluent of the left adrenal, in which an aldosterone producing tumor was localized, an aldosterone level of 8480 ng/100 ml serum was estimated

  20. MED16 and MED23 of Mediator are coactivators of lipopolysaccharide- and heat-shock-induced transcriptional activators

    OpenAIRE

    Kim, Tae Whan; Kwon, Yong-Jae; Kim, Jung Mo; Song, Young-Hwa; Kim, Se Nyun; Kim, Young-Joon

    2004-01-01

    Transcriptional activators interact with diverse proteins and recruit transcriptional machinery to the activated promoter. Recruitment of the Mediator complex by transcriptional activators is usually the key step in transcriptional activation. However, it is unclear how Mediator recognizes different types of activator proteins. To systematically identify the subunits responsible for the signal- and activator-specific functions of Mediator in Drosophila melanogaster, each Mediator subunit was ...

  1. Raised Plasma Aldosterone and Natriuretic Peptides in Atrial Fibrillation

    DEFF Research Database (Denmark)

    Dixen, Ulrik; Ravn, Lasse Steen; Soeby-Rasmussen, Christian;

    2006-01-01

    , present AF at follow-up, total duration of AF disease, ongoing medication, and the LVEF as explanatory variables showed that only ongoing treatment with diuretics was significantly associated (likelihood ratio test, p = 0.0057) with a raised log-transformed plasma aldosterone, although present AF at...... log-transformed plasma Nt-proANP. Likewise, present AF at follow-up (p = 0.0008) as well as age (p < 0.0001) were associated with high log-transformed plasma Nt-proBNP. CONCLUSIONS: In patients with earlier AF, AF at long-term follow-up visit was independently associated with raised levels of Nt...... follow-up was related to a high aldosterone level (p = 0.09). For the natriuretic peptides, present AF at follow-up (p < 0.0001), age (p < 0.0001), female gender (p = 0.0047), ischemic heart disease (p = 0.0154), and ongoing treatment with sotalol (p = 0.0003) were all independently associated with high...

  2. Antiurolithic activity of Origanum vulgare is mediated through multiple pathways

    Directory of Open Access Journals (Sweden)

    Khan Aslam

    2011-10-01

    .Cr, possibly mediated through inhibition of CaOx crystallization, antioxidant, renal epithelial cell protective and antispasmodic activities, rationalizes its medicinal use in urolithiasis.

  3. Treatment with patiromer decreases aldosterone in patients with chronic kidney disease and hyperkalemia on renin-angiotensin system inhibitors.

    Science.gov (United States)

    Weir, Matthew R; Bakris, George L; Gross, Coleman; Mayo, Martha R; Garza, Dahlia; Stasiv, Yuri; Yuan, Jinwei; Berman, Lance; Williams, Gordon H

    2016-09-01

    Elevated serum aldosterone can be vasculotoxic and facilitate cardiorenal damage. Renin-angiotensin system inhibitors reduce serum aldosterone levels and/or block its effects but can cause hyperkalemia. Patiromer, a nonabsorbed potassium binder, decreases serum potassium in patients with chronic kidney disease on renin-angiotensin system inhibitors. Here we examined the effect of patiromer treatment on serum aldosterone, blood pressure, and albuminuria in patients with chronic kidney disease on renin-angiotensin system inhibitors with hyperkalemia (serum potassium 5.1-6.5 mEq/l). We analyzed data from the phase 3 OPAL-HK study (4-week initial treatment phase of 243 patients; 8-week randomized withdrawal phase of 107 patients). In the treatment phase, the (mean ± standard error) serum potassium was decreased concordantly with the serum aldosterone (-1.99 ± 0.51 ng/dl), systolic/diastolic blood pressure (-5.64 ± 1.04 mm Hg/-3.84 ± 0.69 mm Hg), and albumin-to-creatinine ratio (-203.7 ± 54.7 mg/g), all in a statistically significant manner. The change in the plasma renin activity (-0.44 ± 0.63 μg/l/hr) was not significant. In the withdrawal phase, mean aldosterone levels were sustained with patiromer (+0.23 ± 1.07 ng/dl) and significantly increased with placebo (+2.78 ± 1.25 ng/dl). Patients on patiromer had significant reductions in mean systolic/diastolic blood pressure (-6.70 ± 1.59/-2.15 ± 1.06 mm Hg), whereas those on placebo did not (-1.21 ± 1.89 mm Hg/+1.72 ± 1.26 mm Hg). Significant changes in plasma renin activity were found only in the placebo group (-3.90 ± 1.41 μg/l/hr). Thus, patiromer reduced serum potassium and aldosterone levels independent of plasma renin activity in patients with chronic kidney disease and hyperkalemia on renin-angiotensin system inhibitors. PMID:27350174

  4. Mediated Electron Transfer at Redox Active Monolayers. Part 4: Kinetics of Redox Enzymes Coupled With Electron Mediators

    Directory of Open Access Journals (Sweden)

    Michael E.G. Lyons

    2003-01-01

    Full Text Available A detailed kinetic analysis of the pertinent physical processes underlying the operation of enzyme electrodes immobilized within alkane thiol self assembled monolayers is developed. These electrodes utilize a soluble mediator, which partitions into the monolayer, regenerates the active catalytic form of the enzyme and is re-oxidized at the underlying support electrode surface giving rise to a current which reflects kinetic events at the enzyme surface. Both the enzyme/substrate and enzyme mediator kinetics have been quantified fully in terms of a ping-pong mechanism for the former and Michaelis-Menten kinetics for the latter. The effect of substrate and mediator diffusion in solution have also been specifically considered and the latter processes have been shown to result in a complex expression for the reaction flux. Four limiting kinetic cases have been enumerated and simple expressions for the reaction flux in each of these rate limiting situations have been developed. Kinetic case diagrams have been presented as an aid to mechanistic diagnosis. The complicating effects of diffusive loss of reduced mediator from the enzyme layer have also been examined and the relation between the observed flux corresponding to reduced mediator oxidation at the support electrode and the substrate reaction flux in the enzyme layer have been quantified in terms of an efficiency factor. Results extracted from recently published practical realizations of immobilized monolayer enzyme systems have been discussed in the context of the proposed model analysis.

  5. Aldosterone antagonists in monotherapy are protective against streptozotocin-induced diabetic nephropathy in rats.

    Science.gov (United States)

    Banki, Nora F; Ver, Agota; Wagner, Laszlo J; Vannay, Adam; Degrell, Peter; Prokai, Agnes; Gellai, Renata; Lenart, Lilla; Szakal, Dorottya-Nagy; Kenesei, Eva; Rosta, Klara; Reusz, Gyorgy; Szabo, Attila J; Tulassay, Tivadar; Baylis, Chris; Fekete, Andrea

    2012-01-01

    Angiotensin converting enzyme inhibitors (ACEi) and angiotensin II receptor blockers (ARB) are the standard clinical therapy of diabetic nephropathy (DN), while aldosterone antagonists are only used as adjuncts. Previously in experimental DN we showed that Na/K ATPase (NKA) is mislocated and angiotensin II leads to superimposed renal progression. Here we investigated the monotherapeutic effect of aldosterone blockers on the progression of DN and renal NKA alteration in comparison to ACEi and ARBs. Streptozotocin-diabetic rats developing DN were treated with aldosterone antagonists; ACEi and ARB. Renal function, morphology, protein level and tubular localization of NKA were analyzed. To evaluate the effect of high glucose per se; HK-2 proximal tubular cells were cultured in normal or high concentration of glucose and treated with the same agents. Aldosterone antagonists were the most effective in ameliorating functional and structural kidney damage and they normalized diabetes induced bradycardia and weight loss. Aldosterone blockers also prevented hyperglycemia and diabetes induced increase in NKA protein level and enzyme mislocation. A monotherapy with aldosterone antagonists might be as, or more effective than ACEi or ARBs in the prevention of STZ-induced DN. Furthermore the alteration of the NKA could represent a novel pathophysiological feature of DN and might serve as an additional target of aldosterone blockers. PMID:22761931

  6. Aldosterone antagonists in monotherapy are protective against streptozotocin-induced diabetic nephropathy in rats.

    Directory of Open Access Journals (Sweden)

    Nora F Banki

    Full Text Available Angiotensin converting enzyme inhibitors (ACEi and angiotensin II receptor blockers (ARB are the standard clinical therapy of diabetic nephropathy (DN, while aldosterone antagonists are only used as adjuncts. Previously in experimental DN we showed that Na/K ATPase (NKA is mislocated and angiotensin II leads to superimposed renal progression. Here we investigated the monotherapeutic effect of aldosterone blockers on the progression of DN and renal NKA alteration in comparison to ACEi and ARBs. Streptozotocin-diabetic rats developing DN were treated with aldosterone antagonists; ACEi and ARB. Renal function, morphology, protein level and tubular localization of NKA were analyzed. To evaluate the effect of high glucose per se; HK-2 proximal tubular cells were cultured in normal or high concentration of glucose and treated with the same agents. Aldosterone antagonists were the most effective in ameliorating functional and structural kidney damage and they normalized diabetes induced bradycardia and weight loss. Aldosterone blockers also prevented hyperglycemia and diabetes induced increase in NKA protein level and enzyme mislocation. A monotherapy with aldosterone antagonists might be as, or more effective than ACEi or ARBs in the prevention of STZ-induced DN. Furthermore the alteration of the NKA could represent a novel pathophysiological feature of DN and might serve as an additional target of aldosterone blockers.

  7. Odor-mediated taste learning requires dorsal hippocampus, but not basolateral amygdala activity

    OpenAIRE

    Wheeler, Daniel S.; Chang, Stephen E.; Holland, Peter C

    2012-01-01

    Mediated learning is a unique cognitive phenomenon in which mental representations of physically absent stimuli enter into associations with directly-activated representations of physically present stimuli. Three experiments investigated the functional physiology of mediated learning involving the use of odor-taste associations. In Experiments 1a and 1b, basolateral amygdala lesions failed to attenuate mediated taste aversion learning. In Experiment 2, dorsal hippocampus inactivation impaired...

  8. Active video games: the mediating effect of aerobic fitness on body composition

    Directory of Open Access Journals (Sweden)

    Maddison Ralph

    2012-05-01

    Full Text Available Abstract Background Increased understanding of why and how physical activity impacts on health outcomes is needed to increase the effectiveness of physical activity interventions. A recent randomized controlled trial of an active video game (PlayStation EyeToy™ intervention showed a statistically significant treatment effect on the primary outcome, change from baseline in body mass index (BMI, which favored the intervention group at 24 weeks. In this short paper we evaluate the mediating effects of the secondary outcomes. Objective To identify mediators of the effect of an active video games intervention on body composition. Methods Data from a two-arm parallel randomized controlled trial of an active video game intervention (n = 322 were analyzed. The primary outcome was change from baseline in BMI. A priori secondary outcomes were considered as potential mediators of the intervention on BMI, including aerobic fitness (VO2Max, time spent in moderate-to-vigorous physical activity (MVPA, and food snacking at 24 weeks. Results Only aerobic fitness at 24 weeks met the conditions for mediation, and was a significant mediator of BMI. Conclusion Playing active video games can have a positive effect on body composition in overweight or obese children and this effect is most likely mediated through improved aerobic fitness. Future trials should examine other potential mediators related to this type of intervention. Trial registration Australian New Zealand Clinical Trials Registry Website: http://www.anzctr.org.au Study ID number: ACTRN12607000632493

  9. Hippocampal activity mediates the relationship between circadian activity rhythms and memory in older adults.

    Science.gov (United States)

    Sherman, Stephanie M; Mumford, Jeanette A; Schnyer, David M

    2015-08-01

    Older adults experience parallel changes in sleep, circadian rhythms, and episodic memory. These processes appear to be linked such that disruptions in sleep contribute to deficits in memory. Although more variability in circadian patterns is a common feature of aging and predicts pathology, little is known about how alterations in circadian activity rhythms within older adults influence new episodic learning. Following 10 days of recording sleep-wake patterns using actigraphy, healthy older adults underwent fMRI while performing an associative memory task. The results revealed better associative memory was related to more consistent circadian activity rhythms, independent of total sleep time, sleep efficiency, and level of physical activity. Moreover, hippocampal activity during successful memory retrieval events was positively correlated with associative memory accuracy and circadian activity rhythm (CAR) consistency. We demonstrated that the link between consistent rhythms and associative memory performance was mediated by hippocampal activity. These findings provide novel insight into how the circadian rhythm of sleep-wake cycles are associated with memory in older adults and encourage further examination of circadian activity rhythms as a biomarker of cognitive functioning. PMID:26205911

  10. PVN adenovirus-siRNA injections silencing either NOX2 or NOX4 attenuate aldosterone/NaCl-induced hypertension in mice

    OpenAIRE

    Xue, Baojian; Beltz, Terry G.; Johnson, Ralph F.; GUO Fang; Hay, Meredith; Johnson, Alan Kim

    2011-01-01

    Mineralocorticoid excess increases superoxide production by activating NADPH oxidase (NOX), and intracerebroventricular infusions of NADPH oxidase inhibitors attenuate aldosterone (Aldo)/salt-induced hypertension. It has been hypothesized that increased reactive oxygen species (ROS) in the brain may be a key mechanism in the development of hypertension. The present study investigated the brain regional specificity of NADPH oxidase and the role of NOX2 and NOX4 NADPH oxidase subunits in the hy...

  11. Validity and reliability of instruments to assess potential mediators of children's physical activity: A systematic review

    NARCIS (Netherlands)

    Brown, H.; Hume, C.; Chin A Paw, J.M.M.

    2009-01-01

    This paper aimed to (1) identify potential mediators reported in children's physical activity interventions; and (2) review the psychometric properties of measures of potential mediators included in such interventions. A systematic search of the literature was conducted and studies that reported pot

  12. Participation in Organized Activities and Conduct Problems in Elementary School: The Mediating Effect of Social Skills

    Science.gov (United States)

    Denault, Anne-Sophie; Déry, Michèle

    2015-01-01

    The goal of this study was to test a mediation model in which social skills mediate the relationship between participation in organized activities and conduct problems among elementary school children. Two moderators of these associations were also examined, namely, gender and reception of special education services. A total of 563 children (45%…

  13. Implementation Planning and Progress on Physical Activity Goals: The Mediating Role of Life-Management Strategies

    Science.gov (United States)

    Dugas, Michelle; Gaudreau, Patrick; Carraro, Natasha

    2012-01-01

    This 4-week prospective study examined whether the use of life-management strategies mediates the relationship between implementation planning and short-term progress on physical activity goals. In particular, the strategies of elective selection, compensation, and loss-based selection were disentangled to assess their specific mediating effects.…

  14. Primary aldosteronism associated with severe rhabdomyolysis due to profound hypokalemia.

    Science.gov (United States)

    Goto, Atsushi; Takahashi, Yoshihiko; Kishimoto, Miyako; Minowada, Shigeru; Aibe, Hitoshi; Hasuo, Kanehiro; Kajio, Hiroshi; Noda, Mitsuhiko

    2009-01-01

    A 55-year-old Japanese man was admitted to our hospital with severe weakness. Without measurement of serum electrolyte concentrations, diuretic therapy for hypertension was started 2 weeks prior to admission. Laboratory findings showed profound hypokalemia (1.4 mEq/L), and extreme elevation of the serum creatinine phosphokinase levels (15,760 IU/L), suggesting that the patient had hypokalemic paralysis and hypokalemia-induced rhabdomyolysis. Further evaluations, including adrenal venous sampling strongly suggested that he had primary aldosteronism. He was treated successfully by laparoscopic adrenalectomy. This case provides an important lesson that serum electrolyte concentrations should be measured in hypertensive patients before the administration of antihypertensive agents. PMID:19218772

  15. UPDATES OF THE RENIN‐ANGIOTENSIN‐ALDOSTERON SYSTEM

    Directory of Open Access Journals (Sweden)

    Minela MĂRĂNDUCA

    2013-07-01

    Full Text Available The renin‐angiotensin‐aldosteron system (RAAS is a hormonal system that contributes to regulation of blood pressure and volume of extracellular fluids, in both nor‐ motensive and hypertensive individuals. Hypertension affects the target organs (kidneys and leads to a vicious circle that contributes to maintaining a high arterial pre‐ ssure. Besides the hemodynamic effects of RAAS/Ang II, Ang II has direct impact on structure/function of kidneys, leading to renal injury. Recently, the proinflammatory effect of Ang II has been discovered. Low renal inflamma‐ tion determined by excessive circulating RAAS, mostly at renal level, promotes and continues the renal disease. This review presents the inflammatory mechanisms initiated by Ang II at renal level, which induce development of renal injury. Identification of such mechanisms might lead to the discovery of new therapeutic approaches for hyperten‐ sion/target organs damage.

  16. Dexamethasone suppresion scintiscan in primary aldosteronism with Scintadren

    International Nuclear Information System (INIS)

    The adrenal uptake of 75Se-selenonorcholesterol (Scintadren) was examined in primary aldosteronism under dexamethasone suppresion to establish the value of the adrenal scintigram in distinguishing aldosteronomas from bilateral hyperplasia and to lateralize adenoma, when present. Twenty-eight patients with Conn's syndrome were studied. The results showed that under dexamethasone suppression there is no difference in the time of visualization between the two adrenals in bilateral hyperplasia; the glands appear simultaneously, even if it is asymmetrical, while adenoma always appears earlier than the normal or hyperplastic other side. Thus comparison of the suppressibility of the two adrenals i.e. the time lag in visualization of the gland, is of diagnostic value. (U.K.)

  17. Review of Current Research on Aldosterone and Left Ventricular Remodeling after Acute Myocardial Infarction%醛固酮对急性心肌梗死后左心室重构影响的研究进展

    Institute of Scientific and Technical Information of China (English)

    吴春涛

    2011-01-01

    心力衰竭已经成为影响人们生命和生活质量的主要疾病,心肌梗死后心室重构是其重要原因之一,急性心肌梗死后神经内分泌系统的过度激活对心室重构的影响已成为共识.作为肾素-血管紧张素-醛固酮系统的重要组成部分,醛固酮对于心血管系统的病理生理作用以及醛固酮逃逸现象确定了醛固酮受体拮抗剂在心力衰竭治疗中的决定性地位.现就醛固酮对于急性心肌梗死后左心室重构影响的研究进展作一综述.%Heart failure is a disease that affects people's quality of life, and ventricular remodeling after myocardial infarction is one of the major reasons. There is a consensus on the effect of over-activation of the neuroendocrine system after acute myocardial infarction ( AMI) on ventricular remodeling. Aldosterone acts as an important part of the renin-angiotensin-aldosterone system, and the aldosterone receptor antagonist plays a crucial role in the modern therapeutic regimen for heart failure attributed to aldosterone's pathophysiological effects on the cardiovascular system and aldosterone escape phenomenon. This article reviews the effects of aldosterone on left ventricular remodeling of AMI.

  18. Tip60-mediated acetylation activates transcription independent apoptotic activity of Abl

    Directory of Open Access Journals (Sweden)

    Pandita Tej K

    2011-07-01

    Full Text Available Abstract Background The proto-oncogene, c-Abl encodes a ubiquitously expressed tyrosine kinase that critically governs the cell death response induced by genotoxic agents such as ionizing radiation and cisplatin. The catalytic function of Abl, which is essential for executing DNA damage response (DDR, is normally tightly regulated but upregulated several folds upon IR exposure due to ATM-mediated phosphorylation on S465. However, the mechanism/s leading to activation of Abl's apoptotic activity is currently unknown. Results We investigated the role of acetyl modification in regulating apoptotic activity of Abl and the results showed that DNA strand break-inducing agents, ionizing radiation and bleomycin induced Abl acetylation. Using mass spectrophotometry and site-specific acetyl antibody, we identified Abl K921, located in the DNA binding domain, and conforming to one of the lysine residue in the consensus acetylation motif (KXXK--X3-5--SGS is acetylated following DNA damage. We further observed that the S465 phosphorylated Abl is acetyl modified during DNA damage. Signifying the modification, cells expressing the non acetylatable K921R mutant displayed attenuated apoptosis compared to wild-type in response to IR or bleomycin treatment. WT-Abl induced apoptosis irrespective of new protein synthesis. Furthermore, upon γ-irradiation K921R-Abl displayed reduced chromatin binding compared to wild type. Finally, loss of Abl K921 acetylation in Tip60-knocked down cells and co-precipitation of Abl with Tip60 in DNA damaged cells identified Tip60 as an Abl acetylase. Conclusion Collective data showed that DNA damage-induced K921 Abl acetylation, mediated by Tip60, stimulates transcriptional-independent apoptotic activity and chromatin-associative property thereby defining a new regulatory mechanism governing Abl's DDR function.

  19. The Energy National Mediator. Activity 2008. Annual report

    International Nuclear Information System (INIS)

    This document is the first annual report published by the Energy National Mediator, an independent public institution created in 2006, the missions of which are to recommend solutions to some disputes between electricity and natural gas consumers and producers, and to inform consumers about their rights. The report presents and discusses these both missions, comments the challenges and problems the institution has faced, the approach it has adopted, notably in the relationship with producers and consumers, and the obtained results

  20. Chronobiology and Pharmacologic Modulation of the Renin-Angiotensin-Aldosterone System in Dogs: What Have We Learned?

    Science.gov (United States)

    Mochel, Jonathan P; Danhof, Meindert

    2015-01-01

    Congestive heart failure (CHF) is a primary cause of morbidity and mortality with an increasing prevalence in human and canine populations. Recognition of the role of renin-angiotensin-aldosterone system (RAAS) overactivation in the pathophysiology of CHF has led to significant medical advances. By decreasing systemic vascular resistance and angiotensin II (AII) production, angiotensin-converting enzyme (ACE) inhibitors such as benazepril improve cardiac hemodynamics and reduce mortality in human and dog CHF patients. Although several experiments have pointed out that efficacy of ACE inhibitors depends on the time of administration, little attention is paid to the optimum time of dosing of these medications. A thorough characterization of the chronobiology of the renin cascade has the potential to streamline the therapeutic management of RAAS-related diseases and to help determining the optimal time of drug administration that maximizes efficacy of ACE inhibitors, while minimizing the occurrence of adverse effects. We have developed an integrated pharmacokinetic-pharmacodynamic model that adequately captures the disposition kinetics of the paradigm drug benazeprilat, as well as the time-varying changes of systemic renin-angiotensin-aldosterone biomarkers, without and with ACE inhibition therapy. Based on these chronobiological investigations, the optimal efficacy of ACE inhibitors is expected with bedtime dosing. The data further show that benazepril influences the dynamics of the renin-angiotensin-aldosterone cascade, resulting in a profound decrease in AII and aldosterone (ALD), while increasing renin activity for about 24 h. From the results of recent investigations in human, it is hypothesized that reduction of AII and ALD is one of the drivers of increased survival and improved quality of life in dogs receiving ACE inhibitors. To support and consolidate this hypothesis, additional efforts should be directed toward the collection of circulating RAAS peptides

  1. Cocaine induces astrocytosis through ER stress-mediated activation of autophagy.

    Science.gov (United States)

    Periyasamy, Palsamy; Guo, Ming-Lei; Buch, Shilpa

    2016-08-01

    Cocaine is known to induce inflammation, thereby contributing in part, to the pathogenesis of neurodegeneration. A recent study from our lab has revealed a link between macroautophagy/autophagy and microglial activation. The current study was aimed at investigating whether cocaine could also mediate activation of astrocytes and, whether this process involved induction of autophagy. Our findings demonstrated that cocaine mediated the activation of astrocytes by altering the levels of autophagy markers, such as BECN1, ATG5, MAP1LC3B-II, and SQSTM1 in both human A172 astrocytoma cells and primary human astrocytes. Furthermore, cocaine treatment resulted in increased formation of endogenous MAP1LC3B puncta in human astrocytes. Additionally, astrocytes transfected with the GFP-MAP1LC3B plasmid also demonstrated cocaine-mediated upregulation of the green fluorescent MAP1LC3B puncta. Cocaine-mediated induction of autophagy involved upstream activation of ER stress proteins such as EIF2AK3, ERN1, ATF6 since blockage of autophagy using either pharmacological or gene-silencing approaches, had no effect on cocaine-mediated induction of ER stress. Using both pharmacological and gene-silencing approaches to block either ER stress or autophagy, our findings demonstrated that cocaine-induced activation of astrocytes (measured by increased levels of GFAP) involved sequential activation of ER stress and autophagy. Cocaine-mediated-increased upregulation of GFAP correlated with increased expression of proinflammatory mediators such as TNF, IL1B, and IL6. In conclusion, these findings reveal an association between ER stress-mediated autophagy and astrogliosis in cocaine-treated astrocytes. Intervention of ER stress and/or autophagy signaling would thus be promising therapeutic targets for abrogating cocaine-mediated neuroinflammation. PMID:27337297

  2. Hyper-inflammation and skin destruction mediated by rosiglitazone activation of macrophages in IL-6 deficiency

    DEFF Research Database (Denmark)

    Das, Lopa M; Rosenjack, Julie; Au, Liemin;

    2015-01-01

    -antibodies against IL-6, mimicking IL-6 deficiency in human diseases. IL-6 deficiency when combined with Rosi-mediated upregulation of suppressor of cytokine signaling 3 leads to an altered ratio of nuclear signal transducer and activator of transcription 3/NF-κB that allows hyper-induction of inducible nitric oxide...... mediating hyper-inflammatory macrophage activation significant for diseases associated with IL-6 deficiency....

  3. Does aldosterone play a significant role for regulation of vascular tone?

    DEFF Research Database (Denmark)

    Lyngsø, Kristina Sanne; Assersen, Kasper Bostlund; Dalgaard, Emil Geertsen; Skøtt, Ole; Jensen, Boye L.; Hansen, Pernille B. Lærkegaard

    2016-01-01

    formation and vasoconstrictor effects through endothelial contracting cyclooxygenase derived-factors and a changed calcium handling. The response to aldosterone can change within the same blood vessels depending on the exposure time and status of the endothelium. Chronic responses involve changed levels of...... reactive oxygen radicals, endothelia Na-influx and smooth muscle calcium channel expression and perivascular cells, e.g. mast cells, also participate. Moreover, the vascular effect of aldosterone depends on the status of the endothelium which is likely cause of the very different responses to aldosterone...... and MR treatment observed in human studies going from increased to decreased flow depending on whether the patient had prior cardiovascular disease with endothelial dysfunction or not. A preponderance of constrictor versus dilator responses to aldosterone could therefore be involved in the detrimental...

  4. Impact of aldosterone-producing adenoma on cardiac structures in echocardiography

    OpenAIRE

    Hidaka, Takayuki; Shiwa, Tsuguka; Fujii, Yuichi; Nishioka, Kenji; Utsunomiya, Hiroto; Ishibashi, Ken; Mitsuba, Naoya; Dohi, Yoshihiro; Oda, Noboru; Noma, Kensuke; Kurisu, Satoru; Nakano, Yukiko; Yamamoto, Hideya; Iishida, Takafumi; Higashi, Yukihito

    2013-01-01

    Background Primary aldosteronism (PA) is a most common cause of secondary hypertension. In PA, left ventricular hypertrophy (LVH) is more progressive than in any other cause of hypertension. Aldosterone-producing adenoma (APA) and idiopathic hyperaldosteronism (IHA) are major subtypes of PA. However there is little information concerned with differences of cardiac structures between these two subtypes. Methods We reviewed echocardiographic findings in 46 patients with PA. All patients had a p...

  5. Assessment of DFT methods for computing activation energies of Mo/W-mediated reactions.

    Science.gov (United States)

    Hu, Lianrui; Chen, Hui

    2015-10-13

    Using high level ab initio coupled cluster calculations as reference, the performances of 15 commonly used density functionals (DFs) on activation energy calculations for typical Mo/W-mediated reactions have been systematically assessed for the first time in this work. The selected representative Mo/W-mediated reactions cover a wide range from enzymatic reactions to organometallic reactions, which include Mo-catalyzed aldehyde oxidation (aldehyde oxidoreductase), Mo-catalyzed dimethyl sulfoxide (DMSO) reduction (DMSO reductase), W-catalyzed acetylene hydration (acetylene hydratase), Mo/W-mediated olefin metathesis, Mo/W-mediated olefin epoxidation, W-mediated alkyne metathesis, and W-mediated C-H bond activation. Covering both Mo- and W-mediated reactions, four DFs of B2GP-PLYP, M06, B2-PLYP, and B3LYP are uniformly recommended with and without DFT empirical dispersion correction. Among these four DFs, B3LYP is notably improved in performance by DFT empirical dispersion correction. In addition to the absolute value of calculation error, if the trend of DFT results is also a consideration, B2GP-PLYP, B2-PLYP, and M06 keep better performance than other functionals tested and constitute our final recommendation of DFs for both Mo- and W-mediated reactions. PMID:26574251

  6. Extracellular granzyme K mediates endothelial activation through the cleavage of protease-activated receptor-1.

    Science.gov (United States)

    Sharma, Mehul; Merkulova, Yulia; Raithatha, Sheetal; Parkinson, Leigh G; Shen, Yue; Cooper, Dawn; Granville, David J

    2016-05-01

    Granzymes are a family of serine proteases that were once thought to function exclusively as mediators of cytotoxic lymphocyte-induced target cell death. However, non-apoptotic roles for granzymes, including granzyme K (GzK), have been proposed. As recent studies have observed elevated levels of GzK in the plasma of patients diagnosed with clinical sepsis, we hypothesized that extracellular GzK induces a proinflammatory response in endothelial cells. In the present study, extracellular GzK proteolytically activated protease-activated receptor-1 leading to increased interleukin 6 and monocyte chemotactic protein 1 production in endothelial cells. Enhanced expression of intercellular adhesion molecule 1 along with an increased capacity for adherence of THP-1 cells was also observed. Characterization of downstream pathways implicated the mitogen-activated protein kinase p38 pathway for intercellular adhesion molecule 1 expression, and both the p38 and the extracellular signal-regulated protein kinases 1 and 2 pathways in cytokine production. GzK also increased tumour necrosis factor α-induced inflammatory adhesion molecule expression. Furthermore, the physiological inhibitor of GzK, inter-α-inhibitor protein, significantly inhibited GzK activity in vitro. In summary, extracellular GzK promotes a proinflammatory response in endothelial cells. PMID:26936634

  7. A sociocultural perspective on mediated activity in third grade science

    Science.gov (United States)

    Reveles, John M.; Kelly, Gregory J.; Durán, Richard P.

    2007-02-01

    This ethnographic study of a third grade classroom examined elementary school science learning as a sociocultural accomplishment. The research focused on how a teacher helped his students acquire psychological tools for learning to think and engage in scientific practices as locally defined. Analyses of classroom discourse examined both how the teacher used mediational strategies to frame disciplinary knowledge in science as well as how students internalized and appropriated ways of knowing in science. The study documented and analyzed how students came to appropriate scientific knowledge as their own in an ongoing manner tied to their identities as student scientists. Implications for sociocultural theory in science education research are discussed.

  8. MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Teng, E-mail: tengyu33@yahoo.com [Department of Dermatology, Shandong Ji-ning No. 1 People’s Hospital, Shandong Province 272011 (China); Ji, Jiang [Department of Dermatology, The Second Hospital Affiliated of Soochow University, SuZhou, Jiangsu Province 215000 (China); Guo, Yong-li [Department of Oncology, Shandong Ji-ning No. 1 People’s Hospital, Shandong Province 272011 (China)

    2013-11-08

    Highlights: •Curcumin activates MST1 in melanoma cells. •MST1 mediates curcumin-induced apoptosis of melanoma cells. •ROS production is involved in curcumin-induced MST1 activation. •MST1 mediates curcumin-induced JNK activation in melanoma cells. •MST1 mediates curcumin-induced Foxo3a nuclear translocation and Bim expression. -- Abstract: Different groups including ours have shown that curcumin induces melanoma cell apoptosis, here we focused the role of mammalian Sterile 20-like kinase 1 (MST1) in it. We observed that curcumin activated MST1-dependent apoptosis in cultured melanoma cells. MST1 silencing by RNA interference (RNAi) suppressed curcumin-induced cell apoptosis, while MST1 over-expressing increased curcumin sensitivity. Meanwhile, curcumin induced reactive oxygen species (ROS) production in melanoma cells, and the ROS scavenger, N-acetyl-cysteine (NAC), almost blocked MST1 activation to suggest that ROS might be required for MST1 activation by curcumin. c-Jun N-terminal protein kinase (JNK) activation by curcumin was dependent on MST1, since MST1 inhibition by RNAi or NAC largely inhibited curcumin-induced JNK activation. Further, curcumin induced Foxo3 nuclear translocation and Bim-1 (Foxo3 target gene) expression in melanoma cells, such an effect by curcumin was inhibited by MST1 RNAi. In conclusion, we suggested that MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells.

  9. MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells

    International Nuclear Information System (INIS)

    Highlights: •Curcumin activates MST1 in melanoma cells. •MST1 mediates curcumin-induced apoptosis of melanoma cells. •ROS production is involved in curcumin-induced MST1 activation. •MST1 mediates curcumin-induced JNK activation in melanoma cells. •MST1 mediates curcumin-induced Foxo3a nuclear translocation and Bim expression. -- Abstract: Different groups including ours have shown that curcumin induces melanoma cell apoptosis, here we focused the role of mammalian Sterile 20-like kinase 1 (MST1) in it. We observed that curcumin activated MST1-dependent apoptosis in cultured melanoma cells. MST1 silencing by RNA interference (RNAi) suppressed curcumin-induced cell apoptosis, while MST1 over-expressing increased curcumin sensitivity. Meanwhile, curcumin induced reactive oxygen species (ROS) production in melanoma cells, and the ROS scavenger, N-acetyl-cysteine (NAC), almost blocked MST1 activation to suggest that ROS might be required for MST1 activation by curcumin. c-Jun N-terminal protein kinase (JNK) activation by curcumin was dependent on MST1, since MST1 inhibition by RNAi or NAC largely inhibited curcumin-induced JNK activation. Further, curcumin induced Foxo3 nuclear translocation and Bim-1 (Foxo3 target gene) expression in melanoma cells, such an effect by curcumin was inhibited by MST1 RNAi. In conclusion, we suggested that MST1 activation by curcumin mediates JNK activation, Foxo3a nuclear translocation and apoptosis in melanoma cells

  10. Cellular Mechanisms of Calcium-Mediated Triggered Activity

    Science.gov (United States)

    Song, Zhen

    Life-threatening cardiac arrhythmias continue to pose a major health problem. Ventricular fibrillation, which is a complex form of electrical wave turbulence in the lower chambers of the heart, stops the heart from pumping and is the largest cause of natural death in the United States. Atrial fibrillation, a related form of wave turbulence in the upper heart chambers, is in turn the most common arrhythmia diagnosed in clinical practice. Despite extensive research to date, mechanisms of cardiac arrhythmias remain poorly understood. It is well established that both spatial disorder of the refractory period of heart cells and triggered activity (TA) jointly contribute to the initiation and maintenance of arrhythmias. TA broadly refers to the abnormal generation of a single or a sequence of abnormal excitation waves from a small submillimeter region of the heart in the interval of time between two normal waves generated by the heart's natural pacemaker (the sinoatrial node). TA has been widely investigated experimentally and occurs in several pathological conditions where the intracellular concentration of free Ca2+ ions in heart cells becomes elevated. Under such conditions, Ca2+ can be spontaneously released from intracellular stores, thereby driving an electrogenic current that exchanges 3Na+ ions for one Ca2+ ion across the cell membrane. This current in turn depolarizes the membrane of heart cells after a normal excitation. If this calcium-mediated "delayed after depolarization'' (DAD) is sufficiently large, it can generate an action potential. While the arrhythmogenic importance of spontaneous Ca2+ release and DADs is well appreciated, the conditions under which they occur in heart pathologies remain poorly understood. Calcium overload is only one factor among several other factors that can promote DADs, including sympathetic nerve stimulation, different expression levels of membrane ion channels and calcium handling proteins, and different mutations of those

  11. Renin-angiotensin-aldosterone system in the elderly: rational use of aliskiren in managing hypertension

    Directory of Open Access Journals (Sweden)

    Karl Andersen

    2009-03-01

    Full Text Available Karl AndersenDepartment of Medicine, Division of Cardiology, Landspitali University Hospital, University of Iceland, Reykjavik, IcelandAbstract: The overall purpose of hypertension treatment is 2-fold. First, patients often have symptoms that are related to their high blood pressure and although subtle in many instances may be improved dramatically by blood pressure control. The main reason for blood pressure treatment, however, is to reduce the burden of cardiovascular complications and end organ damage related to the condition. This may be considered the ultimate goal of blood pressure treatment. In this respect, actual blood pressure measurements may be seen as surrogate end points as the organ protective effects of two antihypertensive agents may differ significantly even though their blood pressure lowering effects are similar. Thus beta-blockers, once seen as first-line treatment of hypertension for most patients, now are considered as third- or fourth-line agents according to the latest NICE guidelines (National Institute for Health and Clinical Excellence, www.nice.org.uk/CG034. On the other hand, agents that inhibit the activity of the renin-angiotensin-aldosterone system (RAAS are being established as safe, effective and end organ protective in numerous clinical trials, resulting in their general acceptance as first-line treatment in most patients with stage 2 hypertension. This shift in emphasis from beta-blockers and thiazide diuretics is supported by numerous clinical trials and has proven safe and well tolerated by patients. The impact of this paradigm shift will have to be established in future long-term randomized clinical trials. The optimal combination treatment with respect to end organ protection has yet to be determined. Most combinations will include either a RAAS active agent and calcium channel blocker or two separate RAAS active agents working at different levels of the cascade. In this respect direct renin inhibitors

  12. Study on plasma levels of brain natriuretic peptide, angiotensin and aldosterone in patients with congestive heart failure

    International Nuclear Information System (INIS)

    Objective: To investigate the relationship between brain natriuretic peptide (BNP), angiotensin (AT-II), and aldosterone (ALD) levels in patients with congestive heart failure (CHF). Methods: Plasma levels of BNP (with CLIA) and Angiotensin II (AT-II), aldosterone (ALD) (with RIA) were measured in 98 patients with CHF, 76 cardiac patients without heart faclure, and 86 controls. Results: The plasma levels of BNP, AT-II and ALD in patients (with RIA) CHF were significantly higher than those in the controls. The levels of BNP, AT-II and ALD, CHF patients after therapy were markedly dropped and were significantly lower than those patients before therapy (P<0.01). BNP levels were positively correlated with AT-II and ALD in levels CHF (P<0.05). Conclusion: The over activity of RAA systems may be one of the mechanisms of heart failure. Dynamic observation of changes of BNP, AT-II and ALD may be very useful in assessment of severity and prognosis of patients with CHF. (authors)

  13. Activation of pheromone-sensitive neurons is mediated by conformational activation of pheromone-binding protein.

    Science.gov (United States)

    Laughlin, John D; Ha, Tal Soo; Jones, David N M; Smith, Dean P

    2008-06-27

    Detection of volatile odorants by olfactory neurons is thought to result from direct activation of seven-transmembrane odorant receptors by odor molecules. Here, we show that detection of the Drosophila pheromone, 11-cis vaccenyl acetate (cVA), is instead mediated by pheromone-induced conformational shifts in the extracellular pheromone-binding protein, LUSH. We show that LUSH undergoes a pheromone-specific conformational change that triggers the firing of pheromone-sensitive neurons. Amino acid substitutions in LUSH that are predicted to reduce or enhance the conformational shift alter sensitivity to cVA as predicted in vivo. One substitution, LUSH(D118A), produces a dominant-active LUSH protein that stimulates T1 neurons through the neuronal receptor components Or67d and SNMP in the complete absence of pheromone. Structural analysis of LUSH(D118A) reveals that it closely resembles cVA-bound LUSH. Therefore, the pheromone-binding protein is an inactive, extracellular ligand converted by pheromone molecules into an activator of pheromone-sensitive neurons and reveals a distinct paradigm for detection of odorants. PMID:18585358

  14. Case Report: A case report of acromegaly associated with primary aldosteronism [v1; ref status: indexed, http://f1000r.es/2ny

    Directory of Open Access Journals (Sweden)

    Joanna Matrozova

    2014-02-01

    Full Text Available We describe a patient with a rare combination of acromegaly and primary aldosteronism. A 37 year-old female patient was diagnosed with acromegaly on the basis of typical clinical, hormonal and image characteristics. She presented also with one of the most common co-morbidities – arterial hypertension. The patient has been regularly followed-up and after three surgical interventions, irradiation and adjuvant treatment with a dopamine agonist, acromegaly was finally controlled in 2008 (20 years after diagnosis. Arterial hypertension however, remained a therapeutic problem even after prescription of four antihypertensive drugs. She had normal biochemical parameters, except for low potassium levels 3.2 (3.5-5.6 mmol/l. This raised the suspicion of primary hyperaldosteronism, confirmed by a high aldosterone to plasma rennin activity ratio, high aldosterone level after a Captopril challenge test and visualization of a 35 mm left adrenal nodule on a CT scan. After an operation, the patient recovered from hypokalemia and antihypertensive therapy was reduced to a small dose of a Ca blocker. Co-morbid arterial hypertension is common in acromegaly, though it is rare for this to be caused by Conn’s adenoma. The association of Conn’s adenoma with acromegaly has been interpreted in two lines: as a component of multiple endocrine neoplasia type (MEN1 syndrome or as a direct mitogenic effect of hyperactivated GH-IGF1 axis.

  15. Changes in serum aldosterone are associated with changes in obesity-related factors in normotensive overweight and obese young adults

    OpenAIRE

    Cooper, Jennifer N.; Fried, Linda; Tepper, Ping; Barinas-Mitchell, Emma; Conroy, Molly B.; Evans, Rhobert W.; Brooks, Maria Mori; Woodard, Genevieve A.; Sutton-Tyrrell, Kim

    2013-01-01

    Recent data suggest excess circulating aldosterone promotes cardiometabolic decline. Weight loss may lower aldosterone levels, but little longitudinal data is available in normotensive adults. We aimed to determine if, independent of changes in sodium excretion, reductions in serum aldosterone are associated with favorable changes in obesity-related factors in normotensive overweight/obese young adults. We studied 285 overweight/obese young adult participants (body mass index (BMI) ≥ 25 and <...

  16. Friction mediated by redox-active supramolecular connector molecules.

    Science.gov (United States)

    Bozna, B L; Blass, J; Albrecht, M; Hausen, F; Wenz, G; Bennewitz, R

    2015-10-01

    We report on a friction study at the nanometer scale using atomic force microscopy under electrochemical control. Friction arises from the interaction between two surfaces functionalized with cyclodextrin molecules. The interaction is mediated by connector molecules with (ferrocenylmethyl)ammonium end groups forming supramolecular complexes with the cyclodextrin molecules. With ferrocene connector molecules in solution, the friction increases by a factor of up to 12 compared to control experiments without connector molecules. The electrochemical oxidation of ferrocene to ferrocenium causes a decrease in friction owing to the lower stability of ferrocenium-cyclodextrin complex. Upon switching between oxidative and reduction potentials, a change in friction by a factor of 1.2-1.8 is observed. Isothermal titration calorimetry reveals fast dissociation and rebinding kinetics and thus an equilibrium regime for the friction experiments. PMID:26367352

  17. Early effects of aldosterone on Na-K pump in rat cortical collecting tubules

    International Nuclear Information System (INIS)

    Sustained exposure to aldosterone (Aldo) increases the abundance and activity of the Na-K pump in cortical collecting tubules (CCT). However, the onset and mechanism of the early interaction of Aldo with the CCT pump, especially in adrenal-intact animals, are unclear. We evaluated the short-term effects of the hormone on Na-K-adenosinetriphosphatase (ATPase) activity and on ouabain-sensitive 86Rb uptake, a measure of the transporting rate of the pump, in microdissected CCT from adrenal-intact rats. Incubation with Aldo (10(-8) M, 2 h) had no effect on Na-K-ATPase activity (Vmax), whereas it produced at least a twofold increase in 86Rb uptake. This effect was generated by physiological concentrations of the hormone (threshold 10(-10) M; apparent K1/2 approximately 10(-9) M), after a short lag of less than or equal to 30 min. Incubation with Aldo in the presence of amiloride or nystatin or in a Na-free medium (choline chloride) did not prevent the enhanced 86Rb uptake seen after Aldo alone; possible interpretations of these observations are discussed. We conclude that Aldo produces a rapid stimulation of pump function in CCT that precedes its induction of new pump synthesis; the physiological significance of this effect is suggested by its occurrence in tubules from adrenal-intact animals within the time frame and concentration range of the hormone's effects on electrolyte transport

  18. Neuroprotective Activity of (−)-Epigallocatechin Gallate against Lipopolysaccharide-Mediated Cytotoxicity

    Science.gov (United States)

    Liu, Jin-Biao; Zhou, Li; Wang, Yi-Zhong; Wang, Xu; Zhou, Yu; Ho, Wen-Zhe; Li, Jie-Liang

    2016-01-01

    Lipopolysaccharide- (LPS-) mediated systemic inflammation plays a critical role in neurodegenerative diseases. The present study was conducted to evaluate the protective effects of epigallocatechin gallate (EGCG), the major component in green tea, on LPS-mediated inflammation and neurotoxicity. LPS treatment of macrophages induced expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6). However, EGCG pretreatment of macrophages significantly inhibited LPS-mediated induction of these cytokines. In addition, EGCG significantly diminished LPS-induced inflammatory cytokines in the peripheral mononuclear blood cells (PBMCs). Supernatant from EGCG-pretreated and LPS-activated macrophage cultures was found to be less cytotoxic to neurons than that from non-EGCG-pretreated and LPS-activated macrophage cultures. Furthermore, EGCG treatment of neurons could inhibit LPS-induced production of reactive oxygen species (ROS). Thus EGCG represents a potent and useful neuroprotective agent for inflammation-mediated neurological disorders.

  19. Effect of canrenone and amiloride on the prooxidative effect induced by aldosterone in human mononuclear leukocytes in vitro.

    Science.gov (United States)

    Fiore, C; Sartorato, P; Pagnin, E; Ragazzi, E; Calò, L A; Armanini, D

    2009-12-01

    Clinical studies have demonstrated that aldosterone receptor antagonists do improve the survival of patients with chronic heart diseases and in vitro studies have shown that canrenone blocks the proinflammatory effect of aldosterone in mononucler leukocytes (MNL). The aim of the study was to compare, in the model of human MNL, the effect of potassium-sparing diuretics amiloride and canrenone, on the protein expression of p22phox, a NADPH-oxidase system subunit, that is a principal marker of production of superoxide anions. MNL were isolated from 10 informed healthy volunteers (5 males and 5 females, age range 24-36 yr) and the proteins extracted. p22phox protein expression was evaluated by Western blot and quantified using a densitometric semiquantitative analysis. The experiments showed that aldosterone (10(-8) M) enhances the protein expression of p22phox and that its effect is reversed by co-incubation with canrenone (10(-6) M), while incubation with amiloride (10(-6) M) reduced the prooxidative effect of aldosterone at a significantly lower extent than canrenone. Co-incubation with canrenone, amiloride, and aldosterone together produced the same effect as aldosterone plus canrenone. Incubation with cortisol (40(-8) M) was not effective. These data confirm the prooxidative effect of aldosterone in MNL. The addition of aldosterone-receptor antagonist canrenone produced a higher inhibition than sodium channel blocker amiloride on the effect of aldosterone on p22phox protein expression. PMID:19509473

  20. Interdependent Recruitment of SAGA and Srb Mediator by Transcriptional Activator Gcn4p

    OpenAIRE

    Qiu, Hongfang; Hu, Cuihua; Zhang, Fan; Hwang, Gwo Jiunn; Swanson, Mark J.; Boonchird, Cheunchit; Hinnebusch, Alan G.

    2005-01-01

    Transcriptional activation by Gcn4p is enhanced by the coactivators SWI/SNF, SAGA, and Srb mediator, which stimulate recruitment of TATA binding protein (TBP) and polymerase II to target promoters. We show that wild-type recruitment of SAGA by Gcn4p is dependent on mediator but independent of SWI/SNF function at three different promoters. Recruitment of mediator is also independent of SWI/SNF but is enhanced by SAGA at a subset of Gcn4p target genes. Recruitment of all three coactivators to A...

  1. Is the Effect of Reported Physical Activity on Disability Mediated by Cognitive Performance in White and African American Older Adults?

    OpenAIRE

    Popa, Mihaela A.; Reynolds, Sandra L.; Small, Brent J.

    2009-01-01

    This study examined if reported physical activity has beneficial outcomes on disability through cognitive performance–mediated effects and if these mediation effects are comparable for White and African American elders. Longitudinal data from the Assets and Health Dynamics among the Oldest Old study (N = 4,472) are used to test mediation in multilevel models. During the 7-year follow-up, cognitive performance mediated the effects of reported physical activity on disability in the entire sampl...

  2. TrkB-mediated activation of geranylgeranyltransferase I promotes dendritic morphogenesis

    OpenAIRE

    Zhou, Xiu-Ping; Wu, Kong-Yan; Liang, Bin; Fu, Xiu-Qing; Luo, Zhen-Ge

    2008-01-01

    Dendrite morphogenesis is regulated by neuronal activity or neurotrophins, which may function by activating intrinsic signaling proteins, including Rho family GTPases. Here we report that activity- and brain-derived neurotrophic factor (BDNF)–dependent dendritic morphogenesis requires activation of geranylgeranyltransferase I (GGT), a prenyltransferase that mediates lipid modification of Rho GTPases. Dendritic arborization in cultured hippocampal neurons was promoted by over-expression of GGT...

  3. Socio-economic status and physical activity among adolescents : The mediating role of self-esteem

    NARCIS (Netherlands)

    Veselska, Z.; Geckova, A. Madarasova; Reijneveld, S. A.; van Dijk, J. P.

    2011-01-01

    Objectives: Physical activity is an essential part of a healthy lifestyle in adolescence. Previous studies have shown physical activity to be associated with socio-economic status and self-esteem; the latter association may mediate the former, but evidence on this is lacking. The aim of this study w

  4. Hydrostannation of activated alkynes mediated by Stryker's reagent

    OpenAIRE

    Leung, LT; Chiu, P.

    2006-01-01

    The treatment of activated alkynes with catalytic amounts of Stryker's reagent and tributylstannane resulted in hydrostannation. The reaction proceeds with high regioselectivity to produce α-stannated vinylstannanes exclusively. ©2006 IUPAC.

  5. Evaluation of the effects of occupational noise exposure on serum aldosterone and potassium among industrial workers

    Directory of Open Access Journals (Sweden)

    Sajad Zare

    2016-01-01

    Full Text Available The existing literature indicates that occupational exposure to noise may have adverse effects on workers′ health. The aim of this study was to evaluate the possible effects of exposure to different sound pressure levels (SPLs on serum aldosterone and potassium concentration among Iranian blue collar workers in Golgohar Mining and Industrial Company in Sirjan, Kerman Province, Iran. This case-control study was performed on 45 workers of Golgohar Mining and Industrial Company. The subjects consisted of 30 workers from manufacturing departments and 15 office employees of the mining company. The controls, mainly with administrative jobs were exposed to 72 dBA SPL. Cases, in two separate groups, were exposed to noise levels of 88 dBA and 103 dBA, respectively. Noise intensity was measured at the desired locations. Noise measurements were performed according to the International Organization for Standardization (ISO 9612. To measure the serum aldosterone and potassium concentrations, a 5 mL blood sample was taken from each worker at the specified time intervals and aldosterone concentration was determined using enzyme-linked immunosorbent assay (ELISA test in the laboratory. Repeated measurement and Spearman′s correlation coefficient analysis were used with α = 0.05. Exposure to the different levels of sound pressure resulted in different aldosterone concentrations and meanwhile an increase in the SPL did not affect the concentration of potassium. From 10:00 AM to 10:30 AM, as SPL increased, aldosterone concentrations did not increase significantly but from 13:30 PM to 14:00 PM, raised SPL led to a significant increase in aldosterone concentration. However, there was no correlation between the concentration of potassium and different factors. This study indicated that increases in SPLs affect aldosterone concentration but at the same time do not have significant effects on serum potassium level.

  6. Minocycline and sulforaphane inhibited lipopolysaccharide-mediated retinal microglial activation

    OpenAIRE

    Li-ping YANG; Zhu, Xiu-an; Tso, Mark O.M.

    2007-01-01

    Purpose To elucidate the inhibitory effect of minocycline and sulforaphane on lipopolysaccharide (LPS)-induced retinal microglial activation and the mechanisms through which they exerted their inhibitory effects. Methods Primary retinal microglial cultures were exposed to LPS with or without minocycline and sulforaphane. The mRNA expression of monocyte chemotactic protein (MCP)-1, MCP-3, macrophage inflammatory protein (MIP)-1α, MIP-1β, eotaxin, regulated upon activation normal T-cell express...

  7. Receptor-mediated regional sympathetic nerve activation by leptin.

    OpenAIRE

    Haynes, W G; Morgan, D A; Walsh, S A; Mark, A L; Sivitz, W I

    1997-01-01

    Leptin is a peptide hormone produced by adipose tissue which acts centrally to decrease appetite and increase energy expenditure. Although leptin increases norepinephrine turnover in thermogenic tissues, the effects of leptin on directly measured sympathetic nerve activity to thermogenic and other tissues are not known. We examined the effects of intravenous leptin and vehicle on sympathetic nerve activity to brown adipose tissue, kidney, hindlimb, and adrenal gland in anesthetized Sprague-Da...

  8. [Bone marrow stromal damage mediated by immune response activity].

    Science.gov (United States)

    Vojinović, J; Kamenov, B; Najman, S; Branković, Lj; Dimitrijević, H

    1994-01-01

    The aim of this work was to estimate influence of activated immune response on hematopoiesis in vitro, using the experimental model of BCG immunized BALB/c mice and in patients with chronic immunoactivation: long-lasting infections, autoimmunity or malignancy. We correlated changes in long term bone marrow cultures (Dexter) and NBT reduction with appearance of anemia in patients and experimental model of immunization by BCG. Increased spontaneous NBT reduction pointed out role of macrophage activation in bone marrow stroma damage. Long-term bone marrow cultures showed reduced number of hematopoietic cells, with predomination of fibroblasts and loss of fat cells. This results correlated with anemia and leucocytosis with stimulated myelopoiesis in peripheral blood. Activation of immune response, or acting of any agent that directly changes extracellular matrix and cellularity of bone marrow, may result in microenviroment bone marrow damage that modify hematopoiesis. PMID:18173180

  9. Disorder-mediated crowd control in an active matter system

    Science.gov (United States)

    Pinçe, Erçağ; Velu, Sabareesh K. P.; Callegari, Agnese; Elahi, Parviz; Gigan, Sylvain; Volpe, Giovanni; Volpe, Giorgio

    2016-03-01

    Living active matter systems such as bacterial colonies, schools of fish and human crowds, display a wealth of emerging collective and dynamic behaviours as a result of far-from-equilibrium interactions. The dynamics of these systems are better understood and controlled considering their interaction with the environment, which for realistic systems is often highly heterogeneous and disordered. Here, we demonstrate that the presence of spatial disorder can alter the long-term dynamics in a colloidal active matter system, making it switch between gathering and dispersal of individuals. At equilibrium, colloidal particles always gather at the bottom of any attractive potential; however, under non-equilibrium driving forces in a bacterial bath, the colloids disperse if disorder is added to the potential. The depth of the local roughness in the environment regulates the transition between gathering and dispersal of individuals in the active matter system, thus inspiring novel routes for controlling emerging behaviours far from equilibrium.

  10. Fur-mediated activation of gene transcription in the human pathogen Neisseria gonorrhoeae.

    Science.gov (United States)

    Yu, Chunxiao; Genco, Caroline Attardo

    2012-04-01

    It is well established that the ferric uptake regulatory protein (Fur) functions as a transcriptional repressor in diverse microorganisms. Recent studies demonstrated that Fur also functions as a transcriptional activator. In this study we defined Fur-mediated activation of gene transcription in the sexually transmitted disease pathogen Neisseria gonorrhoeae. Analysis of 37 genes which were previously determined to be iron induced and which contained putative Fur boxes revealed that only 30 of these genes exhibited reduced transcription in a gonococcal fur mutant strain. Fur-mediated activation was established by examining binding of Fur to the putative promoter regions of 16 Fur-activated genes with variable binding affinities observed. Only ∼50% of the newly identified Fur-regulated genes bound Fur in vitro, suggesting that additional regulatory circuits exist which may function through a Fur-mediated indirect mechanism. The gonococcal Fur-activated genes displayed variable transcription patterns in a fur mutant strain, which correlated with the position of the Fur box in each (promoter) region. These results suggest that Fur-mediated direct transcriptional activation is fulfilled by multiple mechanisms involving either competing with a repressor or recruiting RNA polymerase. Collectively, our studies have established that gonococcal Fur functions as an activator of gene transcription through both direct and indirect mechanisms. PMID:22287521

  11. H2S-Mediated Thermal and Photochemical Methane Activation

    NARCIS (Netherlands)

    Baltrusaitis, Jonas; Graaf, de Coen; Broer, Ria; Patterson, Eric V.

    2013-01-01

    Sustainable, low-temperature methods for natural gas activation are critical in addressing current and foreseeable energy and hydrocarbon feedstock needs. Large portions of natural gas resources are still too expensive to process due to their high content of hydrogen sulfide gas (H2S) mixed with met

  12. Activating transcription factor 6 derepression mediates neuroprotection in Huntington disease.

    Science.gov (United States)

    Naranjo, José R; Zhang, Hongyu; Villar, Diego; González, Paz; Dopazo, Xose M; Morón-Oset, Javier; Higueras, Elena; Oliveros, Juan C; Arrabal, María D; Prieto, Angela; Cercós, Pilar; González, Teresa; De la Cruz, Alicia; Casado-Vela, Juan; Rábano, Alberto; Valenzuela, Carmen; Gutierrez-Rodriguez, Marta; Li, Jia-Yi; Mellström, Britt

    2016-02-01

    Deregulated protein and Ca2+ homeostasis underlie synaptic dysfunction and neurodegeneration in Huntington disease (HD); however, the factors that disrupt homeostasis are not fully understood. Here, we determined that expression of downstream regulatory element antagonist modulator (DREAM), a multifunctional Ca2+-binding protein, is reduced in murine in vivo and in vitro HD models and in HD patients. DREAM downregulation was observed early after birth and was associated with endogenous neuroprotection. In the R6/2 mouse HD model, induced DREAM haplodeficiency or blockade of DREAM activity by chronic administration of the drug repaglinide delayed onset of motor dysfunction, reduced striatal atrophy, and prolonged life span. DREAM-related neuroprotection was linked to an interaction between DREAM and the unfolded protein response (UPR) sensor activating transcription factor 6 (ATF6). Repaglinide blocked this interaction and enhanced ATF6 processing and nuclear accumulation of transcriptionally active ATF6, improving prosurvival UPR function in striatal neurons. Together, our results identify a role for DREAM silencing in the activation of ATF6 signaling, which promotes early neuroprotection in HD. PMID:26752648

  13. Activating transcription factor 6 derepression mediates neuroprotection in Huntington disease

    Science.gov (United States)

    Naranjo, José R.; Zhang, Hongyu; Villar, Diego; González, Paz; Dopazo, Xose M.; Morón-Oset, Javier; Higueras, Elena; Oliveros, Juan C.; Arrabal, María D.; Prieto, Angela; Cercós, Pilar; González, Teresa; De la Cruz, Alicia; Casado-Vela, Juan; Rábano, Alberto; Valenzuela, Carmen; Gutierrez-Rodriguez, Marta; Li, Jia-Yi; Mellström, Britt

    2016-01-01

    Deregulated protein and Ca2+ homeostasis underlie synaptic dysfunction and neurodegeneration in Huntington disease (HD); however, the factors that disrupt homeostasis are not fully understood. Here, we determined that expression of downstream regulatory element antagonist modulator (DREAM), a multifunctional Ca2+-binding protein, is reduced in murine in vivo and in vitro HD models and in HD patients. DREAM downregulation was observed early after birth and was associated with endogenous neuroprotection. In the R6/2 mouse HD model, induced DREAM haplodeficiency or blockade of DREAM activity by chronic administration of the drug repaglinide delayed onset of motor dysfunction, reduced striatal atrophy, and prolonged life span. DREAM-related neuroprotection was linked to an interaction between DREAM and the unfolded protein response (UPR) sensor activating transcription factor 6 (ATF6). Repaglinide blocked this interaction and enhanced ATF6 processing and nuclear accumulation of transcriptionally active ATF6, improving prosurvival UPR function in striatal neurons. Together, our results identify a role for DREAM silencing in the activation of ATF6 signaling, which promotes early neuroprotection in HD. PMID:26752648

  14. CRISPR-mediated Activation of Latent HIV-1 Expression.

    Science.gov (United States)

    Limsirichai, Prajit; Gaj, Thomas; Schaffer, David V

    2016-03-01

    Complete eradication of HIV-1 infection is impeded by the existence of cells that harbor chromosomally integrated but transcriptionally inactive provirus. These cells can persist for years without producing viral progeny, rendering them refractory to immune surveillance and antiretroviral therapy and providing a permanent reservoir for the stochastic reactivation and reseeding of HIV-1. Strategies for purging this latent reservoir are thus needed to eradicate infection. Here, we show that engineered transcriptional activation systems based on CRISPR/Cas9 can be harnessed to activate viral gene expression in cell line models of HIV-1 latency. We further demonstrate that complementing Cas9 activators with latency-reversing compounds can enhance latent HIV-1 transcription and that epigenome modulation using CRISPR-based acetyltransferases can also promote viral gene activation. Collectively, these results demonstrate that CRISPR systems are potentially effective tools for inducing latent HIV-1 expression and that their use, in combination with antiretroviral therapy, could lead to improved therapies for HIV-1 infection. PMID:26607397

  15. The predictability of renin-angiotensin-aldosterone system factors for clinical outcome in patients with acute decompensated heart failure.

    Science.gov (United States)

    Nakada, Yasuki; Takahama, Hiroyuki; Kanzaki, Hideaki; Sugano, Yasuo; Hasegawa, Takuya; Ohara, Takahiro; Amaki, Makoto; Funada, Akira; Yoshida, Akemi; Yasuda, Satoshi; Ogawa, Hisao; Anzai, Toshihisa

    2016-06-01

    Although counter-regulation between B-type natriuretic peptide (BNP) levels and renin-angiotensin-aldosterone system (RAAS) activation in heart failure (HF) has been suggested, whether the regulation is preserved in acute decompensated heart failure (ADHF) patients remains unclear. This study aimed to determine: (1) the relationship between RAAS activation and clinical outcomes in ADHF patients, and (2) the relationships between plasma BNP levels and degrees of activation in RAAS factors. This study included ADHF patients (n = 103, NYHA3-4, plasma BNP > 200 pg/ml). We studied the predictability of RAAS factors for cardiovascular events and the relationships between plasma BNP levels and the degrees of activation in RAAS factors, which were evaluated by plasma renin activity (PRA) and aldosterone concentration (PAC). PRA was a strong predictor of cardiovascular (CV) events over 1 year, even after accounting for plasma BNP levels (hazard ratio (HR): 1.04, CI [1.02-1.06], p analysis, p = 0.06). Cut-off value of PRA (5.3 ng/ml/h) was determined by AUC curve. Of the enrolled patients, higher PRA was found in 40 % of them. Although no correlation between the plasma BNP levels and PRA was found (p = 0.36), after adjusting for hemodynamic parameters, eGFR and medication, a correlation was found between them (p = 0.01). Elevated RAAS factors were found in a substantial number of ADHF patients with high plasma BNP levels in the association with hemodynamic state, which predicts poor clinical outcomes. The measurements of RAAS factors help to stratify ADHF patients at risk for further CV events. PMID:25964073

  16. Alterations in vascular function in primary aldosteronism: a cardiovascular magnetic resonance imaging study.

    Science.gov (United States)

    Mark, P B; Boyle, S; Zimmerli, L U; McQuarrie, E P; Delles, C; Freel, E M

    2014-02-01

    Excess aldosterone is associated with increased cardiovascular risk. Aldosterone has a permissive effect on vascular fibrosis. Cardiovascular magnetic resonance imaging (CMR) allows study of vascular function by measuring aortic distensibility. We compared aortic distensibility in primary aldosteronism (PA), essential hypertension (EH) and normal controls and explored the relationship between aortic distensibility and pulse wave velocity (PWV). We studied PA (n=14) and EH (n=33) subjects and age-matched healthy controls (n=17) with CMR, including measurement of aortic distensibility, and measured PWV using applanation tonometry. At recruitment, PA and EH patients had similar blood pressure and left ventricular mass. Subjects with PA had significantly lower aortic distensibility and higher PWV compared with EH and healthy controls. These changes were independent of other factors associated with reduced aortic distensibility, including ageing. There was a significant relationship between increasing aortic stiffness and age in keeping with physical and vascular ageing. As expected, aortic distensibility and PWV were closely correlated. These results demonstrate that PA patients display increased arterial stiffness compared with EH, independent of vascular ageing. The implication is that aldosterone invokes functional impairment of arterial function. The long-term implications of arterial stiffening in aldosterone excess require further study. PMID:23884211

  17. Intrinsic-mediated caspase activation is essential for cardiomyocyte hypertrophy

    OpenAIRE

    Putinski, Charis; ABDUL-GHANI, MOHAMMAD; Stiles, Rebecca; Brunette, Steve; Dick, Sarah A.; Fernando, Pasan; Lynn A. Megeney

    2013-01-01

    Cardiac hypertrophy is a pathologic enlargement of the heart, an alteration that leads to contractile dysfunction and eventual organ failure. The hypertrophy phenotype originates from concentric growth of heart muscle cells and shares many biochemical features with programmed cell death, implying a common molecular origin. Here, we show cell-autonomous activation of a mitochondrial cell death pathway during initial stages of muscle cell hypertrophy, a signal that is essential and sufficient t...

  18. Liposome-mediated cellular delivery of active gp91(phox.

    Directory of Open Access Journals (Sweden)

    Bruno Marques

    Full Text Available BACKGROUND: Gp91(phox is a transmembrane protein and the catalytic core of the NADPH oxidase complex of neutrophils. Lack of this protein causes chronic granulomatous disease (CGD, a rare genetic disorder characterized by severe and recurrent infections due to the incapacity of phagocytes to kill microorganisms. METHODOLOGY: Here we optimize a prokaryotic cell-free expression system to produce integral mammalian membrane proteins. CONCLUSIONS: Using this system, we over-express truncated forms of the gp91(phox protein under soluble form in the presence of detergents or lipids resulting in active proteins with a "native-like" conformation. All the proteins exhibit diaphorase activity in the presence of cytosolic factors (p67(phox, p47(phox, p40(phox and Rac and arachidonic acid. We also produce proteoliposomes containing gp91(phox protein and demonstrate that these proteins exhibit activities similar to their cellular counterpart. The proteoliposomes induce rapid cellular delivery and relocation of recombinant gp91(phox proteins to the plasma membrane. Our data support the concept of cell-free expression technology for producing recombinant proteoliposomes and their use for functional and structural studies or protein therapy by complementing deficient cells in gp91(phox protein.

  19. Adenovirus-mediated wild-type PTEN promoting glioma stem/progenitor cells autophagy activity

    OpenAIRE

    ZHAO Yao-dong; Zi-long WEI; Zhang, Quan-Bin; LOU Mei-qing; HUANG, QIANG

    2013-01-01

    Background PTEN is an anti-oncogene frequently inactivating in glioma. The previous study found that PTEN was closely related to cellular autophagy activity. The purpose of this paper is to study whether the inactivation of PTEN in glioma stem/progenitor cells (GSPCs) is correlative with the low autophagic activity in GSPCs. Methods Wild-type PTEN genes were transferred into GSPCs mediated by adenovirus. The autophagic activity in GSPCs before or after the introduction of wild-type PTEN was...

  20. Socio-economic status and physical activity among adolescents: The mediating role of self-esteem

    OpenAIRE

    Veselska, Z.; Geckova, A. Madarasova; Reijneveld, S.A.; Dijk, J.P. van

    2011-01-01

    Objectives: Physical activity is an essential part of a healthy lifestyle in adolescence. Previous studies have shown physical activity to be associated with socio-economic status and self-esteem; the latter association may mediate the former, but evidence on this is lacking. The aim of this study was to explore the associations of socioeconomic status and the self-esteem of adolescents with physical activity, and their joint effects. Methods: A sample of 3694 elementary-school students from ...

  1. Active video games: the mediating effect of aerobic fitness on body composition

    OpenAIRE

    Maddison Ralph; Mhurchu Cliona; Jull Andrew; Prapavessis Harry; Foley Louise S; Jiang Yannan

    2012-01-01

    Abstract Background Increased understanding of why and how physical activity impacts on health outcomes is needed to increase the effectiveness of physical activity interventions. A recent randomized controlled trial of an active video game (PlayStation EyeToy™) intervention showed a statistically significant treatment effect on the primary outcome, change from baseline in body mass index (BMI), which favored the intervention group at 24 weeks. In this short paper we evaluate the mediating ef...

  2. Effects of CYP7B1-mediated catalysis on estrogen receptor activation.

    Science.gov (United States)

    Pettersson, Hanna; Lundqvist, Johan; Norlin, Maria

    2010-09-01

    Most of the many biological effects of estrogens are mediated via the estrogen receptors ERalpha and beta. The current study examines the role of CYP7B1-mediated catalysis for activation of ER. Several reports suggest that CYP7B1 may be important for hormonal action but previously published studies are contradictory concerning the manner in which CYP7B1 affects ERbeta-mediated response. In the current study, we examined effects of several CYP7B1-related steroids on ER activation, using an estrogen response element (ERE) reporter system. Our studies showed significant stimulation of ER by 5-androstene-3beta,17beta-diol (Aene-diol) and 5alpha-androstane-3beta,17beta-diol (3beta-Adiol). In contrast, the CYP7B1-formed metabolites from these steroids did not activate the receptor, indicating that CYP7B1-mediated metabolism abolishes the ER-stimulating effect of these compounds. The mRNA level of HEM45, a gene known to be stimulated by estrogens, was strongly up-regulated by Aene-diol but not by its CYP7B1-formed metabolite, further supporting this concept. We did not observe stimulation by dehydroepiandrosterone (DHEA) or 7alpha-hydroxy-DHEA, previously suggested to affect ERbeta-mediated response. As part of these studies we examined metabolism of Aene-diol in pig liver which is high in CYP7B1 content. These experiments indicate that CYP7B1-mediated metabolism of Aene-diol is of a similar rate as the metabolism of the well-known CYP7B1 substrates DHEA and 3beta-Adiol. CYP7B1-mediated metabolism of 3beta-Adiol has been proposed to influence ERbeta-mediated growth suppression. Our results indicate that Aene-diol also might be important for ER-related pathways. Our data indicate that low concentrations of Aene-diol can trigger ER-mediated response equally well for both ERalpha and beta and that CYP7B1-mediated conversion of Aene-diol into a 7alpha-hydroxymetabolite will result in loss of action. PMID:20553962

  3. Anti-HBV activity of TRL mediated by recombinant adenovirus

    Institute of Scientific and Technical Information of China (English)

    Wei-Dong Gong; Ya Zhao; Jun Yi; Jin Ding; Jun Liu; Cai-Fang Xue

    2005-01-01

    AIM: To investigate the inhibitive effect of hepatitis B virus (HBV)-TRL on HBV replication. METHODS: Based on previously constructed pcDNA3.1 (-)/TRL, TR, TRmut, HBV core protein (HBVc) and hEDN, interest gene sequences TRL, TR, HBVc and hEDN were inserted into adenovirus shuttle plasmid pDC316 respectively and co-transfected HEK293 cells with rescue plasmid pBHGlox(delta)E1,3Cre to acquire RAd/TRL, TR, HBVcand hEDN. And then RAds were identified, amplified and the titers in HEK293 cells were determined. RAd/TRL and TR were named as the experimental groups, and others were control ones. After HepG2.2.15 cells were infected, RAd/TRL expression was identified by indirect immunofluorescence staining. Supernatant HBV-DNA content was determined by fluorescent quantification PCR. Meanwhile, metabolism of HepG2.2.15 cells was evaluated by MTT colorimetry.RESULTS: RAd vectors with distinct interest gene sequence were successfully constructed. Effective expression of RAd/TRL in HepG2.2.15 cells resulted in a significant decrease of supernatant HBV-DNA content compared to RAd/TR (0.63±0.14 vs 1.60±0.47, P = 0.0266, <0.05) andother control groups (0.63±0.14 vs 8.50±2.78, 8.25±2.26,8.25±2.29, 8.50±1.51, 8.57±1.63, P<0.01). MTT assaysuggested that there were no significant differences in cell metabolic activity between groups (P>0.05).CONCLUSION: The construction and expression of RAd/TRL has been achieved and it could inhibit HBV replication successfully, which has laid the foundation for further research on anti-HBV activity in vivo.

  4. Rhodium mediated bond activation: from synthesis to catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Hung-An [Iowa State Univ., Ames, IA (United States)

    2012-01-01

    Recently, our lab has developed monoanionic tridentate ligand, ToR, showing the corresponding coordination chemistry and catalyst reactivity of magnesium, zirconium, zinc and iridium complexes. This thesis details synthetic chemistry, structural study and catalytic reactivity of the ToR-supported rhodium compounds. Tl[ToR] has been proved to be a superior ligand transfer agent for synthesizing rhodium complexes. The salt metathesis route of Tl[ToM] with [Rh(μ-Cl)(CO)]2 and [Rh(μ- Cl)(COE)]2 gives ToMRh(CO)2 (2.2) and ToMRhH(β3-C8H13) (3.1) respectively while Tl[ToM] with [Rh(μ-Cl)(CO)]2 affords ToPRh(CO)2 (2.3). 2.2 reacts with both strong and weak electrophiles, resulting in the oxazoline N-attacked and the metal center-attacked compounds correspondingly. Using one of the metal center-attacked electrophiles, 2.3 was demonstrated to give high diastereoselectivity. Parallel to COE allylic C-H activation complex 3.1, the propene and allylbenzene allylic C-H activation products have also been synthesized. The subsequent functionalization attempts have been examined by treating with Brønsted acids, Lewis acids, electrophiles, nucleophiles, 1,3-dipolar reagents and reagents containing multiple bonds able to be inserted. Various related complexes have been obtained under these conditions, in which one of the azide insertion compounds reductively eliminates to give an allylic functionalization product stoichiometrically. 3.1 reacts with various primary alcohols to give the decarbonylation dihydride complex ToMRh(H)2CO (4.1). 4.1 shows catalytic reactivity for primary alcohol decarbonylation under a photolytic condition. Meanwhile, 2.2 has been found to be more reactive than 4.1 for catalytic alcohol decarbonylation under the same condition. Various complexes and primary

  5. Photobiologic-mediated fabrication of silver nanoparticles with antibacterial activity.

    Science.gov (United States)

    Lee, Jeong-Ho; Lim, Jeong-Muk; Velmurugan, Palanivel; Park, Yool-Jin; Park, Youn-Jong; Bang, Keuk-Soo; Oh, Byung-Taek

    2016-09-01

    We present the simple, eco-friendly synthesis of silver nanoparticles (AgNPs) using sunlight or green, red, blue, or white LED light together with Dryopteris crassirhizoma rhizome extract (DCRE) as the reducing and capping agent. The preliminary indication of AgNP production was a color change from yellowish green to brown after light exposure in the presence of DCRE. Optimization of parameters such as pH, inoculum dose, and metal ion concentration played an important role in achieving nanoparticle production in 30min. The spectroscopic and morphological properties of AgNPs were characterized using UV-Vis spectroscopy through the presence of a characteristic surface plasmon resonance (SPR) band for AgNPs, Fourier transform infrared spectroscopy (FT-IR), high-resolution transmission electron microscopy (HR-TEM), and X-ray diffraction (XRD). The FT-IR results indicated that the phytochemical present in DCRE was the probable reducing/capping agent involved in the synthesis of AgNPs, and light radiation enhanced nanoparticle production. HR-TEM revealed that the AgNPs were almost spherical with an average size of 5-60nm under all light sources. XRD studies confirmed the face cubic center (fcc) unit cell structure of AgNPs. The synthesized AgNPs showed good antimicrobial activity against Bacillus cereus and Pseudomonas aeruginosa. This study will bring a new insight in ecofriendly production of metal nanoparticles. PMID:27348063

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

    Science.gov (United States)

    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. PMID:27157488

  7. T-bet Activates Th1 Genes through Mediator and the Super Elongation Complex.

    Science.gov (United States)

    Hertweck, Arnulf; Evans, Catherine M; Eskandarpour, Malihe; Lau, Jonathan C H; Oleinika, Kristine; Jackson, Ian; Kelly, Audrey; Ambrose, John; Adamson, Peter; Cousins, David J; Lavender, Paul; Calder, Virginia L; Lord, Graham M; Jenner, Richard G

    2016-06-21

    The transcription factor T-bet directs Th1 cell differentiation, but the molecular mechanisms that underlie this lineage-specific gene regulation are not completely understood. Here, we show that T-bet acts through enhancers to allow the recruitment of Mediator and P-TEFb in the form of the super elongation complex (SEC). Th1 genes are occupied by H3K4me3 and RNA polymerase II in Th2 cells, while T-bet-mediated recruitment of P-TEFb in Th1 cells activates transcriptional elongation. P-TEFb is recruited to both genes and enhancers, where it activates enhancer RNA transcription. P-TEFb inhibition and Mediator and SEC knockdown selectively block activation of T-bet target genes, and P-TEFb inhibition abrogates Th1-associated experimental autoimmune uveitis. T-bet activity is independent of changes in NF-κB RelA and Brd4 binding, with T-bet- and NF-κB-mediated pathways instead converging to allow P-TEFb recruitment. These data provide insight into the mechanism through which lineage-specifying factors promote differentiation of alternative T cell fates. PMID:27292648

  8. T-bet Activates Th1 Genes through Mediator and the Super Elongation Complex

    Directory of Open Access Journals (Sweden)

    Arnulf Hertweck

    2016-06-01

    Full Text Available The transcription factor T-bet directs Th1 cell differentiation, but the molecular mechanisms that underlie this lineage-specific gene regulation are not completely understood. Here, we show that T-bet acts through enhancers to allow the recruitment of Mediator and P-TEFb in the form of the super elongation complex (SEC. Th1 genes are occupied by H3K4me3 and RNA polymerase II in Th2 cells, while T-bet-mediated recruitment of P-TEFb in Th1 cells activates transcriptional elongation. P-TEFb is recruited to both genes and enhancers, where it activates enhancer RNA transcription. P-TEFb inhibition and Mediator and SEC knockdown selectively block activation of T-bet target genes, and P-TEFb inhibition abrogates Th1-associated experimental autoimmune uveitis. T-bet activity is independent of changes in NF-κB RelA and Brd4 binding, with T-bet- and NF-κB-mediated pathways instead converging to allow P-TEFb recruitment. These data provide insight into the mechanism through which lineage-specifying factors promote differentiation of alternative T cell fates.

  9. Activity Theory and Technology Mediated Interaction: Cognitive Scaffolding Using Question-Based Consultation on "Facebook"

    Science.gov (United States)

    Rambe, Patient

    2012-01-01

    Studies that employed activity theory as a theoretical lens for exploring computer-mediated interaction have not adopted social media as their object of study. However, social media provides lecturers with personalised learning environments for diagnostic and prognostic assessments of student mastery of content and deep learning. The integration…

  10. Situated Uses of ICT and Mediation of Joint Activity in a Primary Education Instructional Sequence

    Science.gov (United States)

    Coll, Cesar; Rochera, Maria J.; Colomina, Rosa

    2010-01-01

    Introduction: From a socioconstructivist and situated perspective of teaching and learning processes, the authors analyze how one teacher and her group of 19 sixth-grade pupils use ICT. The study focuses on the way these tools mediate their activity, and evaluates the tools' potential for teaching and learning innovation. Method: A case study…

  11. Sympathetic nervous system activation, arterial shear rate, and flow-mediated dilation.

    NARCIS (Netherlands)

    Thijssen, D.H.J.; Atkinson, C.L.; Ono, K.; Sprung, V.S.; Spence, A.L.; Pugh, C.J.; Green, D.J.

    2014-01-01

    The aim of this study was to examine the contribution of arterial shear to changes in flow-mediated dilation (FMD) during sympathetic nervous system (SNS) activation in healthy humans. Ten healthy men reported to our laboratory four times. Bilateral FMD, shear rate (SR), and catecholamines were exam

  12. Diagnosing and Managing Primary Aldosteronism in Hypertensive Patients: a Case-Based Approach.

    Science.gov (United States)

    Carey, Robert M

    2016-10-01

    Primary aldosteronism with a prevalence of 8 % of hypertension and 20 % of pharmacologically resistant hypertension is the most common secondary cause of hypertension. Yet, the diagnosis is missed in the vast majority of patients. Current clinical practice guidelines recommend screening for primary aldosteronism in patients with sustained elevation of blood pressure (BP) ≥150/100 mmHg if possible prior to initiation of antihypertensive therapy, and in patients with resistant hypertension, spontaneous or diuretic-induced hypokalemia, adrenal incidentaloma, obstructive sleep apnea, a family history of early onset of hypertension or cerebrovascular accident management are systematically reviewed and illustrated with a clinical case. PMID:27566330

  13. Independent effects of aldosterone and potassium on induction of potassium adaptation in rat kidney.

    OpenAIRE

    Stanton, B.; Pan, L.; Deetjen, H; Guckian, V; Giebisch, G

    1987-01-01

    We examined the independent effects of a high potassium diet and increased aldosterone levels on the development of renal potassium adaptation. This condition is defined by the increased ability of the kidneys to excrete an acute infusion of potassium. Rats were adrenalectomized (ADX) and received aldosterone at basal levels (0.5 microgram/100 g X d) or at high levels (2.0 micrograms/100 g X d) for 10 d. In each experimental group, animals received either a control diet or a high potassium di...

  14. Conversion of embryonic stem cells into extraembryonic lineages by CRISPR-mediated activators

    Science.gov (United States)

    Wei, Shu; Zou, Qingjian; Lai, Sisi; Zhang, Quanjun; Li, Li; Yan, Quanmei; Zhou, Xiaoqing; Zhong, Huilin; Lai, Liangxue

    2016-01-01

    The recently emerged CRISPR/Cas9 technique has opened a new perspective on readily editing specific genes. When combined with transcription activators, it can precisely manipulate endogenous gene expression. Here, we enhanced the expression of endogenous Cdx2 and Gata6 genes by CRISPR-mediated activators, thus mouse embryonic stem cells (ESCs) were directly converted into two extraembryonic lineages, i.e., typical trophoblast stem cells (TSCs) and extraembryonic endoderm cells (XENCs), which exhibited characters of TSC or XENC derived from the blastocyst extraembryonic lineages such as cell morphology, specific gene expression, and differentiation ability in vitro and in vivo. This study demonstrates that the cell fate can be effectively manipulated by directly activating of specific endogenous gene expression with CRISPR-mediated activator. PMID:26782778

  15. Activation of glutathione peroxidase via Nrf1 mediates genistein's protection against oxidative endothelial cell injury

    International Nuclear Information System (INIS)

    Cellular actions of isoflavones may mediate the beneficial health effects associated with high soy consumption. We have investigated protection by genistein and daidzein against oxidative stress-induced endothelial injury. Genistein but not daidzein protected endothelial cells from damage induced by oxidative stress. This protection was accompanied by decreases in intracellular glutathione levels that could be explained by the generation of glutathionyl conjugates of the oxidised genistein metabolite, 5,7,3',4'-tetrahydroxyisoflavone. Both isoflavones evoked increased protein expression of γ-glutamylcysteine synthetase-heavy subunit (γ-GCS-HS) and increased cytosolic accumulation and nuclear translocation of Nrf2. However, only genistein led to increases in the cytosolic accumulation and nuclear translocation of Nrf1 and the increased expression of and activity of glutathione peroxidase. These results suggest that genistein-induced protective effects depend primarily on the activation of glutathione peroxidase mediated by Nrf1 activation, and not on Nrf2 activation or increases in glutathione synthesis

  16. Phospholipase D1 Mediates AMP-Activated Protein Kinase Signaling for Glucose Uptake

    OpenAIRE

    Kim, Jong Hyun; Park, Ji-Man; Yea, Kyungmoo; Kim, Hyun Wook; Suh, Pann-Ghill; Ryu, Sung Ho

    2010-01-01

    Background Glucose homeostasis is maintained by a balance between hepatic glucose production and peripheral glucose utilization. In skeletal muscle cells, glucose utilization is primarily regulated by glucose uptake. Deprivation of cellular energy induces the activation of regulatory proteins and thus glucose uptake. AMP-activated protein kinase (AMPK) is known to play a significant role in the regulation of energy balances. However, the mechanisms related to the AMPK-mediated control of gluc...

  17. Phospholipase D1 Mediates AMP-Activated Protein Kinase Signaling for Glucose Uptake

    OpenAIRE

    Jong Hyun Kim; Ji-Man Park; Kyungmoo Yea; Hyun Wook Kim; Pann-Ghill Suh; Sung Ho Ryu

    2010-01-01

    BACKGROUND: Glucose homeostasis is maintained by a balance between hepatic glucose production and peripheral glucose utilization. In skeletal muscle cells, glucose utilization is primarily regulated by glucose uptake. Deprivation of cellular energy induces the activation of regulatory proteins and thus glucose uptake. AMP-activated protein kinase (AMPK) is known to play a significant role in the regulation of energy balances. However, the mechanisms related to the AMPK-mediated control of glu...

  18. Skeletal muscle reflex-mediated changes in sympathetic nerve activity are abnormal in spontaneously hypertensive rats

    OpenAIRE

    Mizuno, Masaki; Murphy, Megan N.; Mitchell, Jere H.; Smith, Scott A.

    2011-01-01

    In hypertension, the blood pressure response to exercise is exaggerated. We demonstrated previously that this heightened pressor response to physical activity is mediated by an overactive skeletal muscle exercise pressor reflex (EPR), with important contributions from its metaboreflex and mechanoreflex components. However, the mechanisms driving the abnormal blood pressure response to EPR activation are largely unknown. Recent evidence in humans suggests that the muscle metaboreflex partially...

  19. Utilidad de la relación aldosterona y actividad renina plasmática en el diagnóstico de hiperaldosteronismo primario Aldosterone/renin ratio in the diagnosis of primary aldosteronism

    Directory of Open Access Journals (Sweden)

    María Carolina Ríos

    2011-12-01

    in Argentina. This ratio was then related with the degree of hypertension and with the presence or absence of hypokalemia. Serum aldosterone and plasma renin activity levels were measured in 123 hypertensive patients after discontinuing all medications that could interfere with the hormonal tests. Patients with an aldosterone/plasma renin activity ratio > 25 were submitted to the saline suppression test (SST to confirm the diagnosis of PA, followed by computed tomography (CT of the abdomen. Twenty patients presented an ARR > 25 (16.4%. Eighteen were submitted to the SST, eight had a diagnosis of PA confirmed with positive SST (6.5%. Of 8 patients who underwent an abdominal CT, two showed adenoma, and six normal adrenal anatomy. All the eight patients with a PA diagnosis belonged to group II and III of hypertension according to Joint National Committee VI (JNC VI, and only 4 (50% were normokalemic. We found a 6.5% prevalence of PA, associated with grade II and III hypertension, and normal potassium values in half of the patients with PA.

  20. Activity and specificity of TRV-mediated gene editing in plants

    KAUST Repository

    Ali, Zahir

    2015-06-03

    © 2015 Taylor and Francis Group, LLC. Plant trait engineering requires efficient targeted genome-editing technologies. Clustered regularly interspaced palindromic repeats (CRISPRs)/ CRISPR associated (Cas) type II system is used for targeted genome-editing applications across eukaryotic species including plants. Delivery of genome engineering reagents and recovery of mutants remain challenging tasks for in planta applications. Recently, we reported the development of Tobacco rattle virus (TRV)-mediated genome editing in Nicotiana benthamiana. TRV infects the growing points and possesses small genome size; which facilitate cloning, multiplexing, and agroinfections. Here, we report on the persistent activity and specificity of the TRV-mediated CRISPR/Cas9 system for targeted modification of the Nicotiana benthamiana genome. Our data reveal the persistence of the TRVmediated Cas9 activity for up to 30 d post-agroinefection. Further, our data indicate that TRV-mediated genome editing exhibited no off-target activities at potential off-targets indicating the precision of the system for plant genome engineering. Taken together, our data establish the feasibility and exciting possibilities of using virus-mediated CRISPR/Cas9 for targeted engineering of plant genomes.

  1. Efficacy-mediated effects of spirituality and physical activity on quality of life: A path analysis

    Directory of Open Access Journals (Sweden)

    Konopack James F

    2012-05-01

    Full Text Available Abstract Background Physical activity has been established as an important determinant of quality of life, particularly among older adults. Previous research has suggested that physical activity’s influence on quality of life perceptions is mediated by changes in self-efficacy and health status. In the same vein, spirituality may be a salient quality of life determinant for many individuals. Methods In the current study, we used path analysis to test a model in which physical activity, spirituality, and social support were hypothesized to influence global quality of life in paths mediated by self-efficacy and health status. Cross-sectional data were collected from a sample of 215 adults (male, n = 51; female, n = 164 over the age of 50 (M age = 66.55 years. Results The analysis resulted in a model that provided acceptable fit to the data (χ2 = 33.10, df = 16, p  Conclusions These results support previous findings of an efficacy-mediated relationship between physical activity and quality of life, with the exception that self-efficacy in the current study was moderately associated with physical health status (.38 but not mental health status. Our results further suggest that spirituality may influence health and well-being via a similar, efficacy-mediated path, with strongest effects on mental health status. These results suggest that those who are more spiritual and physically active report greater quality of life, and the effects of these factors on quality of life may be partially mediated by perceptions of self-efficacy.

  2. DMPD: Macrophage activation through CCR5- and CXCR4-mediated gp120-elicited signalingpathways. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 12960231 Macrophage activation through CCR5- and CXCR4-mediated gp120-elicited signalingpa...ted gp120-elicited signalingpathways. PubmedID 12960231 Title Macrophage activati...on through CCR5- and CXCR4-mediated gp120-elicited signalingpathways. Authors Lee C, Liu QH, Tomkowicz B, Yi

  3. Mediation analysis of the relationship between institutional research activity and patient survival

    DEFF Research Database (Denmark)

    Rochon, Justine; du Bois, Andreas; Lange, Theis

    2014-01-01

    133 patients treated in non-trial hospitals. Taking into account baseline confounders, the overall adjusted hazard ratio of death was 0.58 (95% confidence interval: 0.42 to 0.79). This effect was decomposed into a direct effect of research activity of 0.67 and two indirect effects of 0.93 each......BACKGROUND: Recent studies have suggested that patients treated in research-active institutions have better outcomes than patients treated in research-inactive institutions. However, little attention has been paid to explaining such effects, probably because techniques for mediation analysis...... existing so far have not been applicable to survival data. METHODS: We investigated the underlying mechanisms using a recently developed method for mediation analysis of survival data. Our analysis of the effect of research activity on patient survival was based on 352 patients who had been diagnosed with...

  4. DNMT1-mediated PTEN hypermethylation confers hepatic stellate cell activation and liver fibrogenesis in rats

    Energy Technology Data Exchange (ETDEWEB)

    Bian, Er-Bao; Huang, Cheng; Ma, Tao-Tao; Tao, Hui; Zhang, Hui; Cheng, Chang; Lv, Xiong-Wen; Li, Jun, E-mail: hunkahmu@126.com

    2012-10-01

    Hepatic stellate cell (HSC) activation is an essential event during liver fibrogenesis. Phosphatase and tension homolog deleted on chromosome 10 (PTEN), a tumor suppressor, is a negative regulator of this process. PTEN promoter hypermethylation is a major epigenetic silencing mechanism in tumors. The present study aimed to investigate whether PTEN promoter methylation was involved in HSC activation and liver fibrosis. Treatment of activated HSCs with the DNA methylation inhibitor 5-aza-2′-deoxycytidine (5-azadC) decreased aberrant hypermethylation of the PTEN gene promoter and prevented the loss of PTEN expression that occurred during HSC activation. Silencing DNA methyltransferase 1 (DNMT1) gene also decreased the PTEN gene promoter methylation and upregulated the PTEN gene expression in activated HSC-T6 cells. In addition, knockdown of DNMT1 inhibited the activation of both ERK and AKT pathways in HSC-T6 cells. These results suggest that DNMT1-mediated PTEN hypermethylation caused the loss of PTEN expression, followed by the activation of the PI3K/AKT and ERK pathways, resulting in HSC activation. Highlights: ► PTEN methylation status and loss of PTEN expression ► DNMT1 mediated PTEN hypermethylation. ► Hypermethylation of PTEN contributes to the activation of ERK and AKT pathways.

  5. Dexamethasone-induced apoptosis of osteocytic and osteoblastic cells is mediated by TAK1 activation.

    Science.gov (United States)

    Ding, Heyuan; Wang, Tao; Xu, Dongli; Cha, Bingbing; Liu, Jun; Li, Yiming

    2015-05-01

    Increased apoptosis of osteoblasts and osteocytes is the main mechanism of glucocorticoid (GC)-induced osteonecrosis. In the current study, we investigated whether dexamethasone (Dex)-induced osteoblastic and osteocytic cell apoptosis is mediated through activation of transforming growth factor-β (TGF-β)-activated kinase 1 (TAK1), and whether TAK1 inhibition could promote survival opposing the deleterious effects of Dex. We found that TAK1 was activated by Dex in both osteocytic MLO-Y4 and osteoblastic OB-6 cells, which was prevented by two known anti-oxidants N-acetylcysteine (NAC) and ebselen. TAK1 inhibitors, including LYTAK1 and 5Z-7-oxozeaenol (57-OZ), inhibited Dex-induced apoptosis of MLO-Y4 and OB-6 cells. Meanwhile shRNA-mediated knockdown of TAK1 also suppressed Dex-induced damages to MLO-Y4 and OB-6 cells. On the other hand, exogenously over-expressing TAK1 enhanced Dex-induced MLO-Y4 and OB-6 cell apoptosis. At the molecular level, we found that TAK1 mediated Dex-induced pro-apoptotic Pyk2-JNK activation. Inhibition or silencing of TAK1 almost abolished Pyk2-JNK phosphorylations by Dex in MLO-Y4 and OB-6 cells. TAK1 over-expression, on the other hand, increased Dex's activity on Pyk2-JNK phosphorylations in above cells. We conclude that part of the pro-apoptotic actions of Dex on osteoblastic and osteocytic cells are mediated through TAK1 activation, and that inhibition of TAK1 might protect from GC-induced damages to osteoblasts and osteocytes. PMID:25753204

  6. The Renin-Angiotensin-Aldosterone System in Smokers and Non-Smokers of the Ludwigshafen Risk and Cardiovascular Health (LURIC) Study.

    Science.gov (United States)

    Delgado, Graciela E; Siekmeier, Rüdiger; Krämer, Bernhard K; Grübler, Martin; Tomaschitz, Andreas; März, Winfried; Kleber, Marcus E

    2016-01-01

    High concentrations of renin and aldosterone are risk factors for cardiovascular diseases (CVD) which are the leading cause of morbidity and mortality worldwide. Enhanced activation of the renin-angiotensin-aldosterone system (RAAS) by cigarette smoking has been reported. The aim of our study was to analyze the effect of cigarette smoking on parameters of the RAAS in active smokers (AS) and life-time non-smokers (NS) of the Ludwigshafen Risk and Cardiovascular Health (LURIC) Study as well as the utility of RAAS parameter for risk prediction. We determined the concentration of aldosterone, renin, angiotensin-I and angiotensin-II in participants of the LURIC study. Smoking status was assessed by a questionnaire and the measurement of plasma cotinine concentration. Parameters were log transformed before entering analyses, where appropriate. We used a multivariate Cox regression analysis to assess the effect of parameters on mortality. From the 3316 LURIC participants 777 were AS and 1178 NS. Within a median observation period of 10 years 221 (28.4 %) AS and 302 (25.6 %) NS died. After adjustment for age, gender, and the use of anti-hypertensive medication, only angiotensin-I was significantly different in AS compared to NS with an estimated marginal mean (95 % CI) of 1607 (1541-1673) ng/L and 1719 (1667-1772) ng/L, respectively. For both NS and AS renin and angiotensin-II were directly associated with mortality in the multivariate Cox regression analysis. Angiotensin-I was only associated with increased risk for mortality in NS (HR (95 % CI) of 0.69 (0.53-0.89)). We conclude that increased renin and angiotensin-II are independent predictors of mortality in AS and NS, while angiotensin-I was associated with reduced risk of death in NS only. PMID:27334735

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

    Science.gov (United States)

    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. PMID:26471128

  8. Effect of Salvia Miltiorrhiza on Left Ventricular Hypertrophy and Cardiac Aldosterone in Spontaneously Hypertensive Rats

    Institute of Scientific and Technical Information of China (English)

    韩少杰; 郑智; 任大宏

    2002-01-01

    Summary: Chronic treatment with Salvia Miltiorrhiza preventing left ventricular hypertrophy(LVH) and its possible mechanism-inhibiting the action of cardiac aldosterone in spontaneouslyhypertensive rats (SHR) were investigated. Normotensive Wistar-kyoto (WKY) rats and SHRswere used. Part of SHRs was treated with Salvia Miltiorrhiza for 12 weeks. Systolic blood pres-sure (SBP) and left ventricular mass index were measured. Sections of heart tissue were stainedwith HE method and VanGieson method. Collagen volume fraction was determined in the left ven-tricle by automatically quantitative morphometry. Cardiac aldosterone concentration was measuredby radioimmunoassay. The results indicated that compared with WKY rats, SHRs exhibited high-er SBP, left ventricular collagen volume fraction, and aldosterone concentration (all P<0. 05).After the treatment with Salvia Miltiorrhiza, SBP, left ventricular collagen volume fraction, andaldosterone concentration in SHR were decreased as compared with control group (P<0. 05) ex-cept SBP. It was concluded that chronic treatment with Salvia Miltiorrhiza could prevent left ven-tricular hypertrophy in SHR, significantly inhibit collagen compositions in left ventricle. Themechanism was probably related with the inhibition of the cardiac aldosterone action.

  9. Clinical Implication of the Renin-angiotensin-aldosterone Blockers in Chronic Kidney Disease Undergoing Hemodialysis

    OpenAIRE

    Morishita, Yoshiyuki; Kusano, Eiji; Nagata, Daisuke

    2014-01-01

    The renin-angiotensin-aldosterone system (RAAS) blockers have been widely used in chronic kidney disease patients undergoing hemodialysis; however, whether RAAS blockers have beneficial effects for cardiovascular disease in those patients has not been fully defined. This review focuses on the effects of RAAS blockers in chronic kidney disease undergoing hemodialysis for cardiovascular disease.

  10. In vivo left ventricular function and collagen expression in aldosterone/salt-induced hypertension.

    Science.gov (United States)

    Ramirez-Gil, J F; Delcayre, C; Robert, V; Wassef, M; Trouve, P; Mougenot, N; Charlemagne, D; Lechat, P

    1998-12-01

    Cardiac fibrosis is linked to aldosterone-induced hypertension, but the effects on in vivo left ventricular (LV) function are not established. We studied the relations between in vivo LV function and aldosterone/salt cardiac fibrosis. Adult guinea pigs (GPs) were treated for 3 months with an aldosterone infusion and high-salt diet. This treatment induced arterial hypertension (+35%) and moderate LV hypertrophy (LVH; +60%) without right ventricular (RV) hypertrophy. Echo-Doppler LV assessment demonstrated unaltered cardiac output, stroke volume, or LV relaxation. Type I collagen messenger RNA (mRNA) was significantly increased in both ventricles (LV, +48%; RV, +77%) and accompanied by a significant increase in total collagen deposition (LV, from 0.52% in controls to 4.4% in treated GPs; RV, from 0.82 to 5.5% in treated GPs). Plasma norepinephrine levels increased 2.6-fold (p < 0.01) and correlated with the increase in collagen deposition in both ventricles. Collagen content was not correlated with hypertension or LVH. We conclude that aldosterone administration induces cardiac collagen accumulation and a sympathetic stimulation, which might preserve systolic and diastolic function. PMID:9869498

  11. Changes in serum aldosterone are associated with changes in obesity-related factors in normotensive overweight and obese young adults.

    Science.gov (United States)

    Cooper, Jennifer N; Fried, Linda; Tepper, Ping; Barinas-Mitchell, Emma; Conroy, Molly B; Evans, Rhobert W; Mori Brooks, Maria; Woodard, Genevieve A; Sutton-Tyrrell, Kim

    2013-10-01

    Recent data suggest excess circulating aldosterone promotes cardiometabolic decline. Weight loss may lower aldosterone levels, but little longitudinal data is available in normotensive adults. We aimed to determine whether, independent of changes in sodium excretion, reductions in serum aldosterone are associated with favorable changes in obesity-related factors in normotensive overweight/obese young adults. We studied 285 overweight/obese young adult participants (body mass index ≥ 25 andsodium restriction on vascular health. Body weight, serum aldosterone, 24-h sodium and potassium excretion and obesity-related factors were measured at baseline, 6, 12 and 24 months. Weight loss was significant at 6 (7%), 12 (6%) and 24 months (4%; all Pleptin, insulin, homeostasis assessment of insulin resistance, heart rate, tonic cardiac sympathovagal balance and increases in adiponectin (all Psodium and potassium excretion. Weight loss and reductions in thigh intermuscular fat (intermuscular adipose tissue area; IMAT) were associated with decreases in aldosterone in the subgroup (n=98) with metabolic syndrome (MetS) at baseline (MetS × weight loss, P=0.04; MetS × change in IMAT, P=0.04). Favorable changes in obesity-related factors are associated with reductions in aldosterone in young adults with no risk factors besides excess weight, an important finding, given aldosterone's emergence as an important cardiometabolic risk factor. PMID:23657296

  12. Oxidative modification of caspase-9 facilitates its activation via disulfide-mediated interaction with Apaf-1

    Institute of Scientific and Technical Information of China (English)

    Yong Zuo; Binggang Xiang; Jie Yang; Xuxu Sun; Yumei Wang; Hui Cang; Jing Yi

    2009-01-01

    Intracellular reactive oxygen species (ROS) are known to regulate apoptosis. Activation of caspase-9, the initial caspase in the mitochondrial apoptotic cascade, is closely associated with ROS, but it is unclear whether ROS regulate caspase-9 via direct oxidative modification. The present study aims to elucidate the molecular mechanisms by which ROS mediate caspase-9 activation. Our results show that the cellular oxidative state facilitates caspase-9 activation. Hydrogen peroxide treatment causes the activation of caspase-9 and apoptosis, and promotes an interaction between caspase-9 and apoptotic protease-activating factor 1 (Apaf-1) via disulfide formation. In addition, in an in vitro mitochondria-free system, the thiol-oxidant diamide promotes auto-cleavage of caspase-9 and the caspase-9/ Apaf-1 interaction by facilitating the formation of disulfide-linked complexes. Finally, a point mutation at C403 of caspase-9 impairs both H202-promoted caspase-9 activation and interaction with Apaf-1 through the abolition of disulfide formation. The association between cytochrome c and the C403S mutant is significantly weaker than that between cytochrome c and wild-type caspase-9, indicating that oxidative modification of caspase-9 contributes to apoptosome formation under oxidative stress. Taken together, oxidative modification of caspase-9 by ROS can mediate its interaction with Apaf-1, and can thus promote its auto-cleavage and activation. This mechanism may facilitate apoptosome formation and caspase-9 activation under oxidative stress.

  13. Mitogen-activated protein kinases mediate Mycobacterium tuberculosis–induced CD44 surface expression in monocytes

    Indian Academy of Sciences (India)

    Natarajan Palaniappan; S Anbalagan; Sujatha Narayanan

    2012-03-01

    CD44, an adhesion molecule, has been reported to be a binding site for Mycobacterium tuberculosis (M. tuberculosis) in macrophages and it also mediates mycobacterial phagocytosis, macrophage recruitment and protective immunity against pulmonary tuberculosis in vivo. However, the signalling pathways that are involved in M. tuberculosis–induced CD44 surface expression in monocytic cells are currently unknown. Exposure of THP-1 human monocytes to M. tuberculosis H37Rv and H37Ra induced distinct, time-dependent, phosphorylation of mitogen-activated protein kinase kinase-1, extracellular signal regulated kinase 1/2, mitogen-activated protein kinase kinase 3/6, p38 mitogen-activated protein kinase and c-jun N-terminal kinases. The strains also differed in their usage of CD14 and human leukocyte antigen-DR (HLA-DR) receptors in mediating mitogen-activated protein kinase activation. M. tuberculosis H37Rv strain induced lower CD44 surface expression and tumour necrosis factor-alpha levels, whereas H37Ra the reverse. Using highly specific inhibitors of mitogen-activated protein kinase kinase-1, p38 mitogen-activated protein kinase and c-jun N-terminal kinase, we report that inhibition of extracellular signal regulated kinase 1/2 and c-jun N-terminal kinases increases, but that inhibition of p38 mitogen-activated protein kinase decreases M. tuberculosis–induced CD44 surface expression in THP-1 human monocytes.

  14. Phospholipase D1 mediates AMP-activated protein kinase signaling for glucose uptake.

    Directory of Open Access Journals (Sweden)

    Jong Hyun Kim

    Full Text Available BACKGROUND: Glucose homeostasis is maintained by a balance between hepatic glucose production and peripheral glucose utilization. In skeletal muscle cells, glucose utilization is primarily regulated by glucose uptake. Deprivation of cellular energy induces the activation of regulatory proteins and thus glucose uptake. AMP-activated protein kinase (AMPK is known to play a significant role in the regulation of energy balances. However, the mechanisms related to the AMPK-mediated control of glucose uptake have yet to be elucidated. METHODOLOGY/PRINCIPAL FINDINGS: Here, we found that AMPK-induced phospholipase D1 (PLD1 activation is required for (14C-glucose uptake in muscle cells under glucose deprivation conditions. PLD1 activity rather than PLD2 activity is significantly enhanced by glucose deprivation. AMPK-wild type (WT stimulates PLD activity, while AMPK-dominant negative (DN inhibits it. AMPK regulates PLD1 activity through phosphorylation of the Ser-505 and this phosphorylation is increased by the presence of AMP. Furthermore, PLD1-S505Q, a phosphorylation-deficient mutant, shows no changes in activity in response to glucose deprivation and does not show a significant increase in (14C-glucose uptake when compared to PLD1-WT. Taken together, these results suggest that phosphorylation of PLD1 is important for the regulation of (14C-glucose uptake. In addition, extracellular signal-regulated kinase (ERK is stimulated by AMPK-induced PLD1 activation through the formation of phosphatidic acid (PA, which is a product of PLD. An ERK pharmacological inhibitor, PD98059, and the PLD inhibitor, 1-BtOH, both attenuate (14C-glucose uptake in muscle cells. Finally, the extracellular stresses caused by glucose deprivation or aminoimidazole carboxamide ribonucleotide (AICAR; AMPK activator regulate (14C-glucose uptake and cell surface glucose transport (GLUT 4 through ERK stimulation by AMPK-mediated PLD1 activation. CONCLUSIONS/SIGNIFICANCE: These results

  15. Progress of Aldosterone Breakthroughs%醛固酮逃逸的研究进展

    Institute of Scientific and Technical Information of China (English)

    郭建淑

    2011-01-01

    Renin-angiotensin-aldosterone system inhibitors have become leading drugs in the treatment of hypertension and chronic heart failure. Angiotensin-converting-enzyme inhibitors( ACEI) and angiotensin-receptor blockers ( ARB) do not, however, uniformly suppress the renin-angiotensin-aldosterone system. After a period of therapy with ACEI or ARB, plasma aldosterone levels are elevated in some patients. This phenomenon, is known as 'aldosterone escape' or 'aldosterone breakthrough'. The key questions of how breakthrough happens , how often breakthrough occurs and whether breakthrough leads, to worse outcomes have yet to be definitively answered. This review summarizes reported research on the incidence and mechanism of aldosterone breakthrough, we also discuss the difference of aldosterone breakthrough during the treatment with ACEI or ARB.%肾素-血管紧张素-醛固酮系统抑制剂已成为治疗高血压及心力衰竭的主要药物,然而血管紧张素转换酶抑制剂与血管紧张素Ⅱ受体拮抗剂并没有充分的阻断过度激活的肾素-血管紧张素-醛固酮系统.在经过血管紧张素转换酶抑制剂或血管紧张素Ⅱ受体拮抗剂治疗一段时间后,一部分患者血浆醛固酮水平有所升高,即"醛固酮逃逸现象".该现象的发生率及机制,对临床治疗的影响等重要问题一直不完全清楚,现就醛固醛逃逸现象的发生率、机制、在血管紧张素转换酶抑制剂和血管紧张素Ⅱ受体拮抗剂治疗中的区别等在近年的研究进展做一概要的综述.

  16. Women, Physical Activity, and Quality of Life: Self-concept as a Mediator.

    Science.gov (United States)

    Gonzalo Silvestre, Tamara; Ubillos Landa, Silvia

    2016-01-01

    The objectives of this research are: (a) analyze the incremental validity of physical activity's (PA) influence on perceived quality of life (PQL); (b) determine if PA's predictive power is mediated by self-concept; and (c) study if results vary according to a unidimensional or multidimensional approach to self-concept measurement. The sample comprised 160 women from Burgos, Spain aged 18 to 45 years old. Non-probability sampling was used. Two three-step hierarchical regression analyses were applied to forecast PQL. The hedonic quality-of-life indicators, self-concept, self-esteem, and PA were included as independent variables. The first regression analysis included global self-concept as predictor variable, while the second included its five dimensions. Two mediation analyses were conducted to see if PA's ability to predict PQL was mediated by global and physical self-concept. Results from the first regression shows that self-concept, satisfaction with life, and PA were significant predictors. PA slightly but significantly increased explained variance in PQL (2.1%). In the second regression, substituting global self-concept with its five constituent factors, only the physical dimension and satisfaction with life predicted PQL, while PA ceased to be a significant predictor. Mediation analysis revealed that only physical self-concept mediates the relationship between PA and PQL (z = 1.97, p global self-concept. Physical self-concept was the strongest predictor and approximately 32.45 % of PA's effect on PQL was mediated by it. This study's findings support a multidimensional view of self-concept, and represent a more accurate image of the relationship between PQL, PA, and self-concept. PMID:26898406

  17. Inhibition of acetyl-CoA carboxylase by cystamine may mediate the hypotriglyceridemic activity of pantethine.

    Science.gov (United States)

    McCarty, M F

    2001-03-01

    Pantethine is a versatile and well-tolerated hypolipidemic agent whose efficacy in this regard appears to be mediated by its catabolic product cystamine, a nucleophile which avidly attacks disulfide groups. An overview of pantethine research suggests that the hypotriglyceridemic activity of pantethine reflects cystamine-mediated inhibition of the hepatic acetyl-CoA carboxylase, which can be expected to activate hepatic fatty acid oxidation. Inhibition of HMG-CoA reductase as well as a more distal enzyme in the cholesterol synthetic pathway may account for pantethine's hypocholesterolemic effects. If pantethine does indeed effectively inhibit hepatic acetyl-CoA carboxylase, it may have adjuvant utility in the hepatothermic therapy of obesity. As a safe and effective compound of natural origin, pantethine merits broader use in the management of hyperlipidemias. PMID:11359352

  18. Effect of Acute Exercise on ANP-Induced Inhibition of Aldosterone Release in Rat Adrenals

    OpenAIRE

    SUDA, Kazuhiro; Hagiwara, Hiromi; Komabayashi, Takao; Izawa, Tetsuya; Imai, Hajime; Hayashi, Tomoya; Era, Seiichi

    2004-01-01

    SUDA, K., HAGIWARA, H., KOMABAYASHI, T., IZAWA, T., IMAI, H., HAYASHI, T. and ERA, s., Effect of Acute Exercise on ANP-Induced Inhibition of Aldosterone Release in Rat Adrenals. Abv. Exerc. Sports Physiol., Vol.10, No.2 pp.43-47, 2004. We intide (ANP)-induced inhibition of aldosterone release in rat adrenals. The rats ran on treadmill for two hours. Immediately after the exercise, the adrenals were excised and used for an aldosterone release experiment, an ANP binding assay, and a guanylate c...

  19. Cytotoxic activities of amentoflavone against human breast and cervical cancers are mediated by increasing of PTEN expression levels due to peroxisomes proliferate-activated receptor {gamma} activation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eunjung; Shin, Soyoung; Lee, Jeeyoung; Lee, So Jung; Kim, Jinkyoung; Yoon, Doyoung; Kim, Yangmee [Konkuk Univ., Seoul (Korea, Republic of); Woo, Eunrhan [Chosun Univ., Gwangju (Korea, Republic of)

    2012-07-15

    Human peroxisomes proliferate-activated receptor gamma (hPPAR{gamma}) has been implicated in numerous pathologies, including obesity, diabetes, and cancer. Previously, we verified that amentoflavone is an activator of hPPAR{gamma} and probed the molecular basis of its action. In this study, we investigated the mechanism of action of amentoflavone in cancer cells and demonstrated that amentoflavone showed strong cytotoxicity against MCF-7 and HeLa cancer cell lines. We showed that hPPAR{gamma} expression in MCF-7 and HeLa cells is specifically stimulated by amentoflavone, and suggested that amentoflavone-induced cytotoxic activities are mediated by activation of hPPAR{gamma} in these two cancer cell lines. Moreover, amentoflavone increased PTEN levels in these two cancer cell lines, indicating that the cytotoxic activities of amentoflavone are mediated by increasing of PTEN expression levels due to hPPAR{gamma} activation.

  20. Cytotoxic activities of amentoflavone against human breast and cervical cancers are mediated by increasing of PTEN expression levels due to peroxisomes proliferate-activated receptor γ activation

    International Nuclear Information System (INIS)

    Human peroxisomes proliferate-activated receptor gamma (hPPARγ) has been implicated in numerous pathologies, including obesity, diabetes, and cancer. Previously, we verified that amentoflavone is an activator of hPPARγ and probed the molecular basis of its action. In this study, we investigated the mechanism of action of amentoflavone in cancer cells and demonstrated that amentoflavone showed strong cytotoxicity against MCF-7 and HeLa cancer cell lines. We showed that hPPARγ expression in MCF-7 and HeLa cells is specifically stimulated by amentoflavone, and suggested that amentoflavone-induced cytotoxic activities are mediated by activation of hPPARγ in these two cancer cell lines. Moreover, amentoflavone increased PTEN levels in these two cancer cell lines, indicating that the cytotoxic activities of amentoflavone are mediated by increasing of PTEN expression levels due to hPPARγ activation

  1. Leptin‐Induced Endothelial Dysfunction Is Mediated by Sympathetic Nervous System Activity

    OpenAIRE

    Wang, Jintao; Wang, Hui; Luo, Wei; Guo, Chiao; Wang, Julia; Chen, Y.E.; Chang, Lin; Eitzman, Daniel T.

    2013-01-01

    Background The adipocyte‐derived hormone leptin is elevated in obesity and may contribute to vascular risk associated with obesity. The mechanism(s) by which leptin affects vascular disease is unclear, although leptin has been shown to increase sympathetic activity. The aim of this study was to investigate the effect of leptin treatment on endothelial function and the role of the local sympathetic nervous system in mediating these effects. Methods and Results Recombinant leptin was administer...

  2. Aqueous-mediated Michael Addition of Active Methylene Compounds with Nitroalkenes

    Institute of Scientific and Technical Information of China (English)

    董文凯; 徐东成; 谢建武

    2012-01-01

    A simple, atom economical and highly efficient green protocol has been developed for the synthesis of Michael adducts of nitroalkenes and 2-amino-2-chromene derivatives by Michael addition of active methylene compounds (such as malononitrile and ethyl cyanoacetate) to nitroalkenes under aqueous-mediated conditions. This green approach provided the desired products in high yields and the reaction scope proved to be quite broad.

  3. PolyADP-ribose polymerase is a coactivator for AP-2-mediated transcriptional activation.

    OpenAIRE

    Kannan, P; Yu, Y; Wankhade, S; Tainsky, M A

    1999-01-01

    Overexpression of transcription factor AP-2 has been implicated in the tumorigenicity of the human teratocarcinoma cell lines PA-1 that contain an activated ras oncogene. Here we show evidence that overexpression of AP-2 sequesters transcriptional coactivators which results in self-inhibition. We identified AP-2-interacting proteins and determined whether these proteins were coactivators for AP-2-mediated transcription. One such interacting protein is polyADP-ribose polymerase (PARP). PARP su...

  4. Activation of the Endothelin System Mediates Pathological Angiogenesis during Ischemic Retinopathy

    OpenAIRE

    Patel, Chintan; Narayanan, S. Priya; Zhang, Wenbo; Xu, Zhimin; Sukumari-Ramesh, Sangeetha; Dhandapani, Krishnan M.; Caldwell, R. William; Caldwell, Ruth B.

    2014-01-01

    Retinopathy of prematurity adversely affects premature infants because of oxygen-induced damage of the immature retinal vasculature, resulting in pathological neovascularization (NV). Our pilot studies using the mouse model of oxygen-induced retinopathy (OIR) showed marked increases in angiogenic mediators, including endothelins and endothelin receptor (EDNR) A. We hypothesized that activation of the endothelin system via EDNRA plays a causal role in pathological angiogenesis and up-regulatio...

  5. DNA-PK mediates AKT activation and apoptosis inhibition in clinically acquired platinum resistance.

    Science.gov (United States)

    Stronach, Euan A; Chen, Michelle; Maginn, Elaina N; Agarwal, Roshan; Mills, Gordon B; Wasan, Harpreet; Gabra, Hani

    2011-11-01

    Clinical resistance to chemotherapy is a frequent event in cancer treatment and is closely linked to poor outcome. High-grade serous (HGS) ovarian cancer is characterized by p53 mutation and high levels of genomic instability. Treatment includes platinum-based chemotherapy and initial response rates are high; however, resistance is frequently acquired, at which point treatment options are largely palliative. Recent data indicate that platinum-resistant clones exist within the sensitive primary tumor at presentation, implying resistant cell selection after treatment with platinum chemotherapy. The AKT pathway is central to cell survival and has been implicated in platinum resistance. Here, we show that platinum exposure induces an AKT-dependent, prosurvival, DNA damage response in clinically platinum-resistant but not platinum-sensitive cells. AKT relocates to the nucleus of resistant cells where it is phosphorylated specifically on S473 by DNA-dependent protein kinase (DNA-PK), and this activation inhibits cisplatin-mediated apoptosis. Inhibition of DNA-PK or AKT, but not mTORC2, restores platinum sensitivity in a panel of clinically resistant HGS ovarian cancer cell lines: we also demonstrate these effects in other tumor types. Resensitization is associated with prevention of AKT-mediated BAD phosphorylation. Strikingly, in patient-matched sensitive cells, we do not see enhanced apoptosis on combining cisplatin with AKT or DNA-PK inhibition. Insulin-mediated activation of AKT is unaffected by DNA-PK inhibitor treatment, suggesting that this effect is restricted to DNA damage-mediated activation of AKT and that, clinically, DNA-PK inhibition might prevent platinum-induced AKT activation without interfering with normal glucose homeostasis, an unwanted toxicity of direct AKT inhibitors. PMID:22131882

  6. DNA-PK Mediates AKT Activation and Apoptosis Inhibition in Clinically Acquired Platinum Resistance12

    Science.gov (United States)

    Stronach, Euan A; Chen, Michelle; Maginn, Elaina N; Agarwal, Roshan; Mills, Gordon B; Wasan, Harpreet; Gabra, Hani

    2011-01-01

    Clinical resistance to chemotherapy is a frequent event in cancer treatment and is closely linked to poor outcome. High-grade serous (HGS) ovarian cancer is characterized by p53 mutation and high levels of genomic instability. Treatment includes platinum-based chemotherapy and initial response rates are high; however, resistance is frequently acquired, at which point treatment options are largely palliative. Recent data indicate that platinum-resistant clones exist within the sensitive primary tumor at presentation, implying resistant cell selection after treatment with platinum chemotherapy. The AKT pathway is central to cell survival and has been implicated in platinum resistance. Here, we show that platinum exposure induces an AKT-dependent, prosurvival, DNA damage response in clinically platinum-resistant but not platinum-sensitive cells. AKT relocates to the nucleus of resistant cells where it is phosphorylated specifically on S473 by DNA-dependent protein kinase (DNA-PK), and this activation inhibits cisplatin-mediated apoptosis. Inhibition of DNA-PK or AKT, but not mTORC2, restores platinum sensitivity in a panel of clinically resistant HGS ovarian cancer cell lines: we also demonstrate these effects in other tumor types. Resensitization is associated with prevention of AKT-mediated BAD phosphorylation. Strikingly, in patient-matched sensitive cells, we do not see enhanced apoptosis on combining cisplatin with AKT or DNA-PK inhibition. Insulin-mediated activation of AKT is unaffected by DNA-PK inhibitor treatment, suggesting that this effect is restricted to DNA damage-mediated activation of AKT and that, clinically, DNA-PK inhibition might prevent platinum-induced AKT activation without interfering with normal glucose homeostasis, an unwanted toxicity of direct AKT inhibitors. PMID:22131882

  7. DNA-PK Mediates AKT Activation and Apoptosis Inhibition in Clinically Acquired Platinum Resistance

    Directory of Open Access Journals (Sweden)

    Euan A. Stronach

    2011-11-01

    Full Text Available Clinical resistance to chemotherapy is a frequent event in cancer treatment and is closely linked to poor outcome. High-grade serous (HGS ovarian cancer is characterized by p53 mutation and high levels of genomic instability. Treatment includes platinum-based chemotherapy and initial response rates are high; however, resistance is frequently acquired, at which point treatment options are largely palliative. Recent data indicate that platinumresistant clones exist within the sensitive primary tumor at presentation, implying resistant cell selection after treatment with platinum chemotherapy. The AKT pathway is central to cell survival and has been implicated in platinum resistance. Here, we show that platinum exposure induces an AKT-dependent, prosurvival, DNA damage response in clinically platinum-resistant but not platinum-sensitive cells. AKT relocates to the nucleus of resistant cells where it is phosphorylated specifically on S473 by DNA-dependent protein kinase (DNA-PK, and this activation inhibits cisplatin-mediated apoptosis. Inhibition of DNA-PK or AKT, but not mTORC2, restores platinum sensitivity in a panel of clinically resistant HGS ovarian cancer cell lines: we also demonstrate these effects in other tumor types. Re-sensitization is associated with prevention of AKT-mediated BAD phosphorylation. Strikingly, in patient-matched sensitive cells, we do not see enhanced apoptosis on combining cisplatin with AKT or DNA-PK inhibition. Insulin-mediated activation of AKT is unaffected by DNA-PK inhibitor treatment, suggesting that this effect is restricted to DNA damage–mediated activation of AKT and that, clinically, DNA-PK inhibition might prevent platinum-induced AKT activation without interfering with normal glucose homeostasis, an unwanted toxicity of direct AKT inhibitors.

  8. Polymorphisms of renin-angiotensin-aldosterone system gene in chinese han patients with nonfamilial atrial fibrillation.

    Directory of Open Access Journals (Sweden)

    Li-Qun Zhao

    Full Text Available Atrial fibrillation(AF is the most common arrhythmia in the adult population. The activated renin-angiotensin-aldosterone system (RAS has been reported to play an important role in the pathogenesis of atrial fibrillation. The aim of this study was to investigate the association between nonfamilial AF and polymorphisms in RAS gene.A total of 931 patients with nonfamilial AF, 663 non-AF heart disease patients and 727 healthy subjects were selected. 10 tagSNPs (tSNPs (ACE gene rs8066114, AGT gene rs7539020, rs3789678, rs2478544, rs11568023, rs2478523, rs4762, rs699 and CYP11B2 rs3802230, rs3097 were chosen and genotyped in our study. Single-locus analysis and haplotype analysis were used in this study.In single-locus analysis, we found rs11568023 and rs3789678 in AGT gene were associated with nonfamilial AF in Chinese Han population. AF risk was associated with rs3789678 between the AF group and control groups. Under dominant model, the significant AF risk was observed in rs3789678 between the AF group and non AF heart control group; And the protective effect was found in rs11568023, compared with the non-AF heart disease control group. In multilocus haplotype analysis, the association between frequencies of the haplotypes and AF risk was showed in AGT gene (rs7539020-rs3789678, compared 'TT' haplotype with the common 'TC' haplotype, adjusted for age, gender, LVEF, LVEDD, LAD and frequency of hypertension and diabetes. The diplotype with 'TC', carrying rs3789678-C-allele, was associated with reduced risk of AF between the AF group and the healthy control group. The diplotype with 'TT' haplotype in the same block, carrying rs3789678-T-allele, was associated with increased risk of AF.Via a large-scale case-control study, we found that rs3789678 site was potential susceptible locus of AF whereas rs11568023 was protective factor.

  9. Auxin response factors mediate Arabidopsis organ asymmetry via modulation of KANADI activity.

    Science.gov (United States)

    Pekker, Irena; Alvarez, John Paul; Eshed, Yuval

    2005-11-01

    Members of the KANADI gene family in Arabidopsis thaliana regulate abaxial identity and laminar growth of lateral organs. Promoter APETALA3-mediated ectopic expression of KANADI restricts petal expansion and was used in a genetic screen for factors involved in KANADI-mediated signaling. Through this screen, mutations in ETTIN (ETT; also known as Auxin Response Factor3 [ARF3]) were isolated as second site suppressors and found to ameliorate ectopic KANADI activity throughout the plant as well. Mutant phenotypes of ett are restricted to flowers; however, double mutants with a closely related gene ARF4 exhibit transformation of abaxial tissues into adaxial ones in all aerial parts, resembling mutations in KANADI. Accordingly, the common RNA expression domain of both ARFs was found to be on the abaxial side of all lateral organs. Truncated, negatively acting gene products of strong ett alleles map to an ARF-specific, N-terminal domain of ETT. Such gene products strongly enhance abaxial tissue loss only when ARF activities are compromised. As KANADI is not required for either ETT or ARF4 transcription, and their overexpression cannot rescue kanadi mutants, cooperative activity is implied. ARF proteins are pivotal in mediating auxin responses; thus, we present a model linking transient local auxin gradients and gradual partitioning of lateral organs along the abaxial/adaxial axis. PMID:16199616

  10. Activation of cell-mediated immunity by Morinda citrifolia fruit extract and its constituents.

    Science.gov (United States)

    Murata, Kazuya; Abe, Yumi; Futamura-Masudaa, Megumi; Uwaya, Akemi; Isami, Fumiyuki; Matsuda, Hideaki

    2014-04-01

    Morinda citrifolia, commonly known as noni, is a traditional natural medicine in French Polynesia and Hawaii. Functional foods derived from M. citrifolia fruit have been marketed to help prevent diseases and promote good health. The objective of this study was to assess the effects of M. citrifolia fruit on cell-mediated immunity. In the picryl chloride-induced contact dermatitis test, M. citrifolia fruit extract (Noni-ext) inhibited the suppression of cell-mediated immunity by immunosuppressive substances isolated from freeze-dried ascites of Ehrlich carcinoma-bearing mice (EC-sup). In addition, Noni-ext inhibited reduction of IL-2 production in EC-sup-treated mice and activated natural killer cells in normal mice. These results suggest that Noni-ext has multiple effects on the recovery of cell-mediated immunity. Furthermore, we investigated the active principles of Noni-ext and identified an iridoid glycoside, deacetylasperulosidic acid. Oral administration of deacetylasperulosidic acid inhibited the reduction of ear swelling, and also cancelled the suppression of IL-2 production along with the activation of natural killer cells in the same manner as that of Noni-ext. PMID:24868850

  11. Tetraspanin CD151 Is a Negative Regulator of FcεRI-Mediated Mast Cell Activation.

    Science.gov (United States)

    Abdala-Valencia, Hiam; Bryce, Paul J; Schleimer, Robert P; Wechsler, Joshua B; Loffredo, Lucas F; Cook-Mills, Joan M; Hsu, Chia-Lin; Berdnikovs, Sergejs

    2015-08-15

    Mast cells are critical in the pathogenesis of allergic disease due to the release of preformed and newly synthesized mediators, yet the mechanisms controlling mast cell activation are not well understood. Members of the tetraspanin family are recently emerging as modulators of FcεRI-mediated mast cell activation; however, mechanistic understanding of their function is currently lacking. The tetraspanin CD151 is a poorly understood member of this family and is specifically induced on mouse and human mast cells upon FcεRI aggregation but its functional effects are unknown. In this study, we show that CD151 deficiency significantly exacerbates the IgE-mediated late phase inflammation in a murine model of passive cutaneous anaphylaxis. Ex vivo, FcεRI stimulation of bone marrow-derived mast cells from CD151(-/-) mice resulted in significantly enhanced expression of proinflammatory cytokines IL-4, IL-13, and TNF-α compared with wild-type controls. However, FcεRI-induced mast cell degranulation was unaffected. At the molecular signaling level, CD151 selectively regulated IgE-induced activation of ERK1/2 and PI3K, associated with cytokine production, but had no effect on the phospholipase Cγ1 signaling, associated with degranulation. Collectively, our data indicate that CD151 exerts negative regulation over IgE-induced late phase responses and cytokine production in mast cells. PMID:26136426

  12. Polycystin-1 promotes PKCα-mediated NF-κB activation in kidney cells

    International Nuclear Information System (INIS)

    Polycystin-1 (PC1), the PKD1 gene product, is a membrane receptor which regulates many cell functions, including cell proliferation and apoptosis, both typically increased in cyst lining cells in autosomal dominant polycystic kidney disease. Here we show that PC1 upregulates the NF-κB signalling pathway in kidney cells to prevent cell death. Human embryonic kidney cell lines (HEK293CTT), stably expressing a PC1 cytoplasmic terminal tail (CTT), presented increased NF-κB nuclear levels and NF-κB-mediated luciferase promoter activity. This, consistently, was reduced in HEK293 cells in which the endogenous PC1 was depleted by RNA interference. CTT-dependent NF-κB promoter activation was mediated by PKCα because it was blocked by its specific inhibitor Ro-320432. Furthermore, it was observed that apoptosis, which was increased in PC1-depleted cells, was reduced in HEK293CTT cells and in porcine kidney LtTA cells expressing a doxycycline-regulated CTT. Staurosporine, a PKC inhibitor, and parthenolide, a NF-κB inhibitor, significantly reduced the CTT-dependent antiapoptotic effect. These data reveal, therefore, a novel pathway by which polycystin-1 activates a PKCα-mediated NF-κB signalling and cell survival

  13. Brain activation to negative stimuli mediates a relationship between adolescent marijuana use and later emotional functioning

    Directory of Open Access Journals (Sweden)

    Mary M. Heitzeg

    2015-12-01

    Full Text Available This work investigated the impact of heavy marijuana use during adolescence on emotional functioning, as well as the brain functional mediators of this effect. Participants (n = 40 were recruited from the Michigan Longitudinal Study (MLS. Data on marijuana use were collected prospectively beginning in childhood as part of the MLS. Participants were classified as heavy marijuana users (n = 20 or controls with minimal marijuana use. Two facets of emotional functioning—negative emotionality and resiliency (a self-regulatory mechanism—were assessed as part of the MLS at three time points: mean age 13.4, mean age 19.6, and mean age 23.1. Functional neuroimaging data during an emotion-arousal word task were collected at mean age 20.2. Negative emotionality decreased and resiliency increased across the three time points in controls but not heavy marijuana users. Compared with controls, heavy marijuana users had less activation to negative words in temporal, prefrontal, and occipital cortices, insula, and amygdala. Activation of dorsolateral prefrontal cortex to negative words mediated an association between marijuana group and later negative emotionality. Activation of the cuneus/lingual gyrus mediated an association between marijuana group and later resiliency. Results support growing evidence that heavy marijuana use during adolescence affects later emotional outcomes.

  14. Integrin αIIb-mediated PI3K/Akt activation in platelets.

    Directory of Open Access Journals (Sweden)

    Haixia Niu

    Full Text Available Integrin αIIbβ3 mediated bidirectional signaling plays a critical role in thrombosis and haemostasis. Signaling mediated by the β3 subunit has been extensively studied, but αIIb mediated signaling has not been characterized. Previously, we reported that platelet granule secretion and TxA2 production induced by αIIb mediated outside-in signaling is negatively regulated by the β3 cytoplasmic domain residues R(724KEFAKFEEER(734. In this study, we identified part of the signaling pathway utilized by αIIb mediated outside-in signaling. Platelets from humans and gene deficient mice, and genetically modified CHO cells as well as a variety of kinase inhibitors were used for this work. We found that aggregation of TxA2 production and granule secretion by β3Δ724 human platelets initiated by αIIb mediated outside-in signaling was inhibited by the Src family kinase inhibitor PP2 and the PI3K inhibitor wortmannin, respectively, but not by the MAPK inhibitor U0126. Also, PP2 and wortmannin, and the palmitoylated β3 peptide R(724KEFAKFEEER(734, each inhibited the phosphorylation of Akt residue Ser473 and prevented TxA2 production and storage granule secretion. Similarly, Akt phosphorylation in mouse platelets stimulated by the PAR4 agonist peptide AYPGKF was αIIbβ3-dependent, and blocked by PP2, wortmannin and the palmitoylated peptide p-RKEFAKFEEER. Akt was also phosphorylated in response to mAb D3 plus Fg treatment of CHO cells in suspension expressing αIIbβ3-Δ724 or αIIbβ3E(724AERKFERKFE(734, but not in cells expressing wild type αIIbβ3. In summary, SFK(s and PI3K/Akt signaling is utilized by αIIb-mediated outside-in signaling to activate platelets even in the absence of all but 8 membrane proximal residues of the β3 cytoplasmic domain. Our results provide new insight into the signaling pathway used by αIIb-mediated outside-in signaling in platelets.

  15. Inverting Notions of the Biological Role of the Renin → Angiotensin-II → Aldosterone System and the Function of Arterial Pressure as a Metabolism Regulator

    Directory of Open Access Journals (Sweden)

    Vladimir N. Titov

    2014-09-01

    Full Text Available The phylogenetic theory of general pathology postulates that notions of the biological role of arterial pressure (AP in physiology and pathology have been subjected to inversion. The nephron’s activation of the synthesis of the components renin → angiotensin-II (A-II and the augmentation of aldosterone secretion are directed not at an increase in AP but at preserving the volume of the piece of the third world ocean, privatized by each species, - the pool of the intercellular milieu in which, just like millions of years before, there continue to live all cells. Phylogenetically earlier organs cannot regulate the action of a later one in AP phylogenesis – a physical factor in metabolism regulation. It is not the kidneys that increase AP but the vasomotor center, which, increasing AP in the proximal segment and further hydrodynamic pressure in the distal segment of the arterial bed, seeks to reanimate the function of nephrons, the biological function of endoecology and the biological reaction of excretion. In addition to playing a major role in the biological function of locomotion, AP is a physical factor in compensating for impairments in the biological functions of homeostasis, trophology, endoecology, and adaptation. There have formed sequentially three levels of metabolic regulation in phylogenesis. At an autocrine level, there occurs a specific regulation of biochemical reactions. Within paracrinally regulated communities of cells, in the distal segment of the arterial bed, metabolism is regulated by millions of local peristaltic pumps through compensating for the biological reaction of endothelium-dependent vasodilation, microcirculation, and the action of humoral mediators and hormonal principles. In vivo from the level of the vasomotor center metabolism is non-specifically, systemically regulated by the physical factor – AP – through sympathetic activation of the heart; in the proximal segment of the arterial bed and the distal

  16. Response Prediction and Influence of Tolvaptan in Chronic Heart Failure Patients Considering the Interaction of the Renin-Angiotensin-Aldosterone System and Arginine Vasopressin.

    Science.gov (United States)

    Kadota, Muneyuki; Ise, Takayuki; Yagi, Shusuke; Iwase, Takashi; Akaike, Masashi; Ueno, Rie; Kawabata, Yutaka; Hara, Tomoya; Ogasawara, Kozue; Bando, Mika; Bando, Sachiko; Matsuura, Tomomi; Yamaguchi, Koji; Yamada, Hirotsugu; Soeki, Takeshi; Wakatsuki, Tetsuzo; Sata, Masataka

    2016-07-27

    The renin-angiotensin-aldosterone system (RAAS) and arginine vasopressin (AVP) regulate body fluids. Although conventional diuretics have been used for treating heart failure, they activate RAAS and exacerbate renal function. Tolvaptan, a newly developed vasopressin-2 receptor antagonist, elicits aquaresis and improves volume overload in heart failure patients, however, the predictors of tolvaptan effectiveness and the influence on the RAAS and renal function according to tolvaptan therapy are not established. We evaluated 26 chronic heart failure patients receiving therapy with 15 mg/day tolvaptan and examined their laboratory and urinary data before and after tolvaptan therapy. A response to tolvaptan was defined as a body weight decrease by more than 2 kg in a week and a urine volume increase by 500 mL/ day compared with that before tolvaptan administration. Body weight, urine volume, and brain natriuretic peptide levels significantly improved (P < 0.05), without any worsening of renal function represented by serum creatinine, sodium, and potassium. Moreover, no significant changes were observed in the plasma renin activity and plasma aldosterone concentration (PAC). In the responder group, urine osmolality before tolvaptan administration was significantly higher (P < 0.05) but declined significantly after tolvaptan administration (P < 0.05). The AVP/PAC ratio before administration was positively correlated with the efficacy of tolvaptan. Tolvaptan treatment could prevent RAAS activation in chronic heart failure patients. Moreover, monitoring the AVP/PAC ratio may be useful in predicting the tolvaptan response. PMID:27357439

  17. Identification of trans-sialidases as a common mediator of endothelial cell activation by African trypanosomes.

    Directory of Open Access Journals (Sweden)

    Zeinab Ammar

    Full Text Available Understanding African Trypanosomiasis (AT host-pathogen interaction is the key to an "anti-disease vaccine", a novel strategy to control AT. Here we provide a better insight into this poorly described interaction by characterizing the activation of a panel of endothelial cells by bloodstream forms of four African trypanosome species, known to interact with host endothelium. T. congolense, T. vivax, and T. b. gambiense activated the endothelial NF-κB pathway, but interestingly, not T. b. brucei. The parasitic TS (trans-sialidases mediated this NF-κB activation, remarkably via their lectin-like domain and induced production of pro-inflammatory molecules not only in vitro but also in vivo, suggesting a considerable impact on pathogenesis. For the first time, TS activity was identified in T. b. gambiense BSF which distinguishes it from the subspecies T. b. brucei. The corresponding TS were characterized and shown to activate endothelial cells, suggesting that TS represent a common mediator of endothelium activation among trypanosome species with divergent physiopathologies.

  18. Damnacanthal inhibits IgE receptor-mediated activation of mast cells.

    Science.gov (United States)

    Garcia-Vilas, Javier A; Medina, Miguel A; Melo, Fabio R; Pejler, Gunnar; Garcia-Faroldi, Gianni

    2015-05-01

    Damnacanthal, an anthraquinone obtained from the noni fruit (Morinda citrifolia L.), has been described to possess anti-cancer and anti-inflammatory properties. Since mast cells are key players in various inflammatory conditions as well as in cancer, we considered the possibility that the biological actions of damnacanthal, at least partly, could be due to effects on mast cells. Many of the biological activities of mast cells are mediated by IgE receptor cross-linking, which results in degranulation with release of preformed granule mediators, as well as de novo synthesis and release of additional compounds. Here we show that damnacanthal has profound inhibitory activity on mast cell activation through this pathway. The release of the granule compounds beta-hexosaminidase and tryptase release was completely abrogated by damnacanthal at doses that were non-toxic to mast cells. In addition, damnacanthal inhibited activation-dependent pro-inflammatory gene induction, as well as cytokine/chemokine release in response to mast cell stimulation. The mechanism underlying damnacanthal inhibition was linked to impaired phosphorylation of Syk and Akt. Furthermore, damnacanthal inhibited mast cell activation in response to calcium ionophore A23187. Altogether, the data presented here demonstrate that damnacanthal inhibits mast cell activation induced by different stimuli and open a new window for the use of this compound as a mast cell stabilizer. PMID:25656801

  19. β2-Glycoprotein I Is a Cofactor for t-PA–Mediated Plasminogen Activation

    Science.gov (United States)

    Bu, Chunya; Gao, Lei; Xie, Weidong; Zhang, Jainwei; He, Yuhong; Cai, Guoping; McCrae, Keith R

    2010-01-01

    Regulation of the conversion of plasminogen to plasmin by tissue-type plasminogen activator (t-PA) is critical in the control of fibrin deposition. While several plasminogen activators have been described, soluble plasma cofactors that stimulate fibrinolysis have not been characterized. Here, we report that the abundant plasma glycoprotein, β2-glycoprotein I (β2GPI), stimulates t-PA–dependent plasminogen activation in the fluid phase and within a fibrin gel. The region within β2GPI responsible for stimulating t-PA activity is at least partially contained within β2GPI domain V. β2GPI bound t-PA with high affinity (Kd ~ 20 nM), stimulated t-PA amidolytic activity, and caused an overall 20-fold increase in the catalytic efficiency (kcat/Km) of t-PA–mediated conversion of Glu-plasminogen to plasmin. Moreover, depletion of β2GPI from plasma led to diminished rates of clot lysis, with restoration of normal lysis rates following β2GPI repletion. Finally, stimulation of t-PA–mediated plasminogen activity by β2GPI was inhibited by monoclonal anti-β2GPI antibodies, as well as by anti-β2GPI antibodies from patients with antiphospholipid syndrome (APS). These findings suggest that β2GPI may be an endogenous regulator of fibrinolysis. Impairment of β2GPI-stimulated fibrinolysis by anti-β2GPI antibodies may contribute to the development of thrombosis in patients with APS. PMID:19180513

  20. Sphingosine-1-phosphate mediates epidermal growth factor-induced muscle satellite cell activation

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Yosuke, E-mail: cynagata@mail.ecc.u-tokyo.ac.jp; Ohashi, Kazuya; Wada, Eiji; Yuasa, Yuki; Shiozuka, Masataka; Nonomura, Yoshiaki; Matsuda, Ryoichi

    2014-08-01

    Skeletal muscle can regenerate repeatedly due to the presence of resident stem cells, called satellite cells. Because satellite cells are usually quiescent, they must be activated before participating in muscle regeneration in response to stimuli such as injury, overloading, and stretch. Although satellite cell activation is a crucial step in muscle regeneration, little is known of the molecular mechanisms controlling this process. Recent work showed that the bioactive lipid sphingosine-1-phosphate (S1P) plays crucial roles in the activation, proliferation, and differentiation of muscle satellite cells. We investigated the role of growth factors in S1P-mediated satellite cell activation. We found that epidermal growth factor (EGF) in combination with insulin induced proliferation of quiescent undifferentiated mouse myoblast C2C12 cells, which are also known as reserve cells, in serum-free conditions. Sphingosine kinase activity increased when reserve cells were stimulated with EGF. Treatment of reserve cells with the D-erythro-N,N-dimethylsphingosine, Sphingosine Kinase Inhibitor, or siRNA duplexes specific for sphingosine kinase 1, suppressed EGF-induced C2C12 activation. We also present the evidence showing the S1P receptor S1P2 is involved in EGF-induced reserve cell activation. Moreover, we demonstrated a combination of insulin and EGF promoted activation of satellite cells on single myofibers in a manner dependent on SPHK and S1P2. Taken together, our observations show that EGF-induced satellite cell activation is mediated by S1P and its receptor. - Highlights: • EGF in combination with insulin induces proliferation of quiescent C2C12 cells. • Sphingosine kinase activity increases when reserve cells are stimulated with EGF. • EGF-induced activation of reserve cells is dependent on sphingosine kinase and ERK. • The S1P receptor S1P2 is involved in EGF-induced reserve cell activation. • EGF-induced reserve cell activation is mediated by S1P and its

  1. Sphingosine-1-phosphate mediates epidermal growth factor-induced muscle satellite cell activation

    International Nuclear Information System (INIS)

    Skeletal muscle can regenerate repeatedly due to the presence of resident stem cells, called satellite cells. Because satellite cells are usually quiescent, they must be activated before participating in muscle regeneration in response to stimuli such as injury, overloading, and stretch. Although satellite cell activation is a crucial step in muscle regeneration, little is known of the molecular mechanisms controlling this process. Recent work showed that the bioactive lipid sphingosine-1-phosphate (S1P) plays crucial roles in the activation, proliferation, and differentiation of muscle satellite cells. We investigated the role of growth factors in S1P-mediated satellite cell activation. We found that epidermal growth factor (EGF) in combination with insulin induced proliferation of quiescent undifferentiated mouse myoblast C2C12 cells, which are also known as reserve cells, in serum-free conditions. Sphingosine kinase activity increased when reserve cells were stimulated with EGF. Treatment of reserve cells with the D-erythro-N,N-dimethylsphingosine, Sphingosine Kinase Inhibitor, or siRNA duplexes specific for sphingosine kinase 1, suppressed EGF-induced C2C12 activation. We also present the evidence showing the S1P receptor S1P2 is involved in EGF-induced reserve cell activation. Moreover, we demonstrated a combination of insulin and EGF promoted activation of satellite cells on single myofibers in a manner dependent on SPHK and S1P2. Taken together, our observations show that EGF-induced satellite cell activation is mediated by S1P and its receptor. - Highlights: • EGF in combination with insulin induces proliferation of quiescent C2C12 cells. • Sphingosine kinase activity increases when reserve cells are stimulated with EGF. • EGF-induced activation of reserve cells is dependent on sphingosine kinase and ERK. • The S1P receptor S1P2 is involved in EGF-induced reserve cell activation. • EGF-induced reserve cell activation is mediated by S1P and its

  2. Aryl hydrocarbon receptor mediates both proinflammatory and anti-inflammatory effects in lipopolysaccharide-activated microglia.

    Science.gov (United States)

    Lee, Yi-Hsuan; Lin, Chun-Hua; Hsu, Pei-Chien; Sun, Yu-Yo; Huang, Yu-Jie; Zhuo, Jiun-Horng; Wang, Chen-Yu; Gan, Yu-Ling; Hung, Chia-Chi; Kuan, Chia-Yi; Shie, Feng-Shiun

    2015-07-01

    The aryl hydrocarbon receptor (AhR) regulates peripheral immunity; but its role in microglia-mediated neuroinflammation in the brain remains unknown. Here, we demonstrate that AhR mediates both anti-inflammatory and proinflammatory effects in lipopolysaccharide (LPS)-activated microglia. Activation of AhR by its ligands, formylindolo[3,2-b]carbazole (FICZ) or 3-methylcholanthrene (3MC), attenuated LPS-induced microglial immune responses. AhR also showed proinflammatory effects, as evidenced by the findings that genetic silence of AhR ameliorated the LPS-induced microglial immune responses and LPS-activated microglia-mediated neurotoxicity. Similarly, LPS-induced expressions of tumor necrosis factor α (TNFα) and inducible nitric oxide synthase (iNOS) were reduced in the cerebral cortex of AhR-deficient mice. Intriguingly, LPS upregulated and activated AhR in the absence of AhR ligands via the MEK1/2 signaling pathway, which effects were associated with a transient inhibition of cytochrome P450 1A1 (CYP1A1). Although AhR ligands synergistically enhance LPS-induced AhR activation, leading to suppression of LPS-induced microglial immune responses, they cannot do so on their own in microglia. Chromatin immunoprecipitation results further revealed that LPS-FICZ co-treatment, but not LPS alone, not only resulted in co-recruitment of both AhR and NFκB onto the κB site of TNFα gene promoter but also reduced LPS-induced AhR binding to the DRE site of iNOS gene promoter. Together, we provide evidence showing that microglial AhR, which can be activated by LPS, exerts bi-directional effects on the regulation of LPS-induced neuroinflammation, depending on the availability of external AhR ligands. These findings confer further insights into the potential link between environmental factors and the inflammatory brain disorders. PMID:25690886

  3. Peptide-Based Selective Inhibitors of Matrix Metalloproteinase-Mediated Activities

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    Margaret W. Ndinguri

    2012-11-01

    Full Text Available The matrix metalloproteinases (MMPs exhibit a broad array of activities, some catalytic and some non-catalytic in nature. An overall lack of selectivity has rendered small molecule, active site targeted MMP inhibitors problematic in execution. Inhibitors that favor few or individual members of the MMP family often take advantage of interactions outside the enzyme active site. We presently focus on peptide-based MMP inhibitors and probes that do not incorporate conventional Zn2+ binding groups. In some cases, these inhibitors and probes function by binding only secondary binding sites (exosites, while others bind both exosites and the active site. A myriad of MMP mediated-activities beyond selective catalysis can be inhibited by peptides, particularly cell adhesion, proliferation, motility, and invasion. Selective MMP binding peptides comprise highly customizable, unique imaging agents. Areas of needed improvement for MMP targeting peptides include binding affinity and stability.

  4. Endothelin potentiates TRPV1 via ETA receptor-mediated activation of protein kinase C

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    Furkert Jens

    2007-11-01

    Full Text Available Abstract Background Endothelin-1 (ET-1 both stimulates nociceptors and sensitizes them to noxious stimuli, an effect probably mediated by the ETA receptor (ETAR expressed in sensory neurons. The cellular mechanisms of this ET-1-mediated effect are only poorly understood. TRPV1, the heat-, pH- and capsaicin-sensitive cation channel already known to be modulated by a number of cellular mediators released in response to noxious stimuli and during inflammation, is a potential target for the action of ET-1. Results We studied the effects of ET-1 on TRPV1 in sensory neurons from the dorsal root ganglion (DRG and in HEK293 cells coexpressing TRPV1 and the ETAR. Specific 125I-ET-1 binding sites (817 ± 92 fmol/mg were detected in membrane preparations of DRG with an ETAR/ETBR ratio of 60:40. In an immunofluorescence analysis, coexpression of TRPV1 and the ETAR was found in a subpopulation of primary sensory neurons. ET-1 strongly potentiated capsaicin-induced TRPV1 currents in some neurons, and in HEK293 cells co-expressing TRPV1 and the ETAR. Weaker potentiation was observed in HEK293 cells coexpressing TRPV1 and the ETBR. ETAR activation also increased responses to low pH and heat. In HEK293 cells, strong potentiation of TRPV1 like that induced by ET-1 via the ETAR could be induced by PKC activation, but not with activators of the adenylyl cyclase or the PKA pathway. Furthermore, inhibition of PKC with bisindolylmaleimide X (BIM X or mutation of the PKC phosphorylation site S800 completely prevented ETAR-mediated potentiation. Conclusion We conclude that ET-1 potentiates TRPV1 by a PKC-dependent mechanism and that this could play a major role in the algogenic and hyperalgesic effects of ET-1 described in previous studies.

  5. Dual effects of TGF-β on ERα-mediated estrogenic transcriptional activity in breast cancer

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    Cao Xu

    2009-11-01

    Full Text Available Abstract Background TGF-β resistance often develops in breast cancer cells that in turn overproduce this cytokine to create a local immunosuppressive environment that fosters tumor growth and exacerbates the invasive and metastatic behavior of the tumor cells themselves. Smads-mediated cross-talk with the estrogen receptor has been implied to play an important role in development and/or progression of breast cancer. We investigated how TGF-β regulates ERα-induced gene transcription and potential mechanisms of frequent TGF-β resistance in breast cancer. Methods Effect of TGF-β on ERα-mediated gene transcription was investigated in breast cancer cell lines using transient transfection, real-time PCR, sequential DNA precipitation, and small interfering RNA assays. The expression of Smads on both human breast cancer cell lines and ERα-positive human breast cancer tissue was evaluated by immunofluorescence and immunohistochemical assays. Results A complex of Smad3/4 mediates TGF-β inhibition of ERα-mediated estrogenic activity of gene transcription in breast cancer cells, and Smad4 is essential and sufficient for such repression. Either overexpression of Smad3 or inhibition of Smad4 leads to the "switch" of TGF-β from a repressor to an activator. Down-regulation and abnormal cellular distribution of Smad4 were associated with some ERα-positive infiltrating human breast carcinoma. There appears a dynamic change of Smad4 expression from benign breast ductal tissue to infiltrating ductal carcinoma. Conclusion These results suggest that aberrant expression of Smad4 or disruption of Smad4 activity lead to the loss of TGF-β suppression of ERα transactivity in breast cancer cells.

  6. New perspectives on mannan-binding lectin-mediated complement activation

    DEFF Research Database (Denmark)

    Degn, Søren Egedal; Thiel, Steffen; Jensenius, Jens Christian

    2007-01-01

    The complement system is an important part of the innate immune system, mediating several major effector functions and modulating adaptive immune responses. Three complement activation pathways exist: the classical pathway (CP), the alternative pathway (AP), and the lectin pathway (LP). The LP is......, allowing C3 activation in the absence of components otherwise believed critical. The classical bypass pathways are dependent on C1 and components of the AP. A recent study has shown the existence also of a lectin bypass pathway dependent on mannan-binding lectin (MBL) and AP components. The emerging...

  7. Role of endocytosis and cathepsin-mediated activation in Nipah virus entry

    International Nuclear Information System (INIS)

    The recent discovery that the Nipah virus (NiV) fusion protein (F) is activated by endosomal cathepsin L raised the question if NiV utilize pH- and protease-dependent mechanisms of entry. We show here that the NiV receptor ephrin B2, virus-like particles and infectious NiV are internalized from the cell surface. However, endocytosis, acidic pH and cathepsin-mediated cleavage are not necessary for the initiation of infection of new host cells. Our data clearly demonstrate that proteolytic activation of the NiV F protein is required before incorporation into budding virions but not after virus entry

  8. Role of 11β-hydroxysteroid dehydrogenase 2 renal activity in potassium homeostasis in rats with chronic renal failure

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    N.L. Yeyati

    2010-01-01

    Full Text Available Aldosterone concentrations vary in advanced chronic renal failure (CRF. The isozyme 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2, which confers aldosterone specificity for mineralocorticoid receptors in distal tubules and collecting ducts, has been reported to be decreased or normal in patients with renal diseases. Our objective was to determine the role of aldosterone and 11β-HSD2 renal microsome activity, normalized for glomerular filtration rate (GFR, in maintaining K+ homeostasis in 5/6 nephrectomized rats. Male Wistar rats weighing 180-220 g at the beginning of the study were used. Rats with experimental CRF obtained by 5/6 nephrectomy (N = 9 and sham rats (N = 10 were maintained for 4 months. Systolic blood pressure and plasma creatinine (Pcr concentration were measured at the end of the experiment. Sodium and potassium excretion and GFR were evaluated before and after spironolactone administration (10 mg·kg-1·day-1 for 7 days and 11β-HSD2 activity on renal microsomes was determined. Systolic blood pressure (means ± SEM; Sham = 105 ± 8 and CRF = 149 ± 10 mmHg and Pcr (Sham = 0.42 ± 0.03 and CRF = 2.53 ± 0.26 mg/dL were higher (P < 0.05 while GFR (Sham = 1.46 ± 0.26 and CRF = 0.61 ± 0.06 mL/min was lower (P < 0.05 in CRF, and plasma aldosterone (Pald was the same in the two groups. Urinary sodium and potassium excretion was similar in the two groups under basal conditions but, after spironolactone treatment, only potassium excretion was decreased in CRF rats (sham = 0.95 ± 0.090 (before vs 0.89 ± 0.09 µEq/min (after and CRF = 1.05 ± 0.05 (before vs 0.37 ± 0.07 µEq/min (after; P < 0.05. 11β-HSD2 activity on renal microsomes was lower in CRF rats (sham = 0.807 ± 0.09 and CRF = 0.217 ± 0.07 nmol·min-1·mg protein-1; P < 0.05, although when normalized for mL GFR it was similar in both groups. We conclude that K+ homeostasis is maintained during CRF development despite normal Pald levels. This adaptation may be mediated by

  9. Psychosocial Mediators of a Faith-Based Physical Activity Intervention: Implications and Lessons Learned from Null Findings

    Science.gov (United States)

    Baruth, Meghan; Wilcox, Sara; Blair, Steve; Hooker, Steve; Hussey, Jim; Saunders, Ruth

    2010-01-01

    Mediation analyses in faith-based physical activity (PA) interventions targeting African-American adults are lacking. The purpose of this study was to examine the psychosocial mediators of a faith-based PA intervention with African-American adults. Churches were randomly assigned to receive immediate or delayed (1-year later) training in PA…

  10. The Guanine Nucleotide Exchange Factor ARNO mediates the activation of ARF and phospholipase D by insulin

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    Fluharty Eric

    2003-09-01

    Full Text Available Abstract Background Phospholipase D (PLD is involved in many signaling pathways. In most systems, the activity of PLD is primarily regulated by the members of the ADP-Ribosylation Factor (ARF family of GTPases, but the mechanism of activation of PLD and ARF by extracellular signals has not been fully established. Here we tested the hypothesis that ARF-guanine nucleotide exchange factors (ARF-GEFs of the cytohesin/ARNO family mediate the activation of ARF and PLD by insulin. Results Wild type ARNO transiently transfected in HIRcB cells was translocated to the plasma membrane in an insulin-dependent manner and promoted the translocation of ARF to the membranes. ARNO mutants: ΔCC-ARNO and CC-ARNO were partially translocated to the membranes while ΔPH-ARNO and PH-ARNO could not be translocated to the membranes. Sec7 domain mutants of ARNO did not facilitate the ARF translocation. Overexpression of wild type ARNO significantly increased insulin-stimulated PLD activity, and mutations in the Sec7 and PH domains, or deletion of the PH or CC domains inhibited the effects of insulin. Conclusions Small ARF-GEFs of the cytohesin/ARNO family mediate the activation of ARF and PLD by the insulin receptor.

  11. Comprehensive re-sequencing of adrenal aldosterone producing lesions reveal three somatic mutations near the KCNJ5 potassium channel selectivity filter.

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    Tobias Åkerström

    Full Text Available BACKGROUND: Aldosterone producing lesions are a common cause of hypertension, but genetic alterations for tumorigenesis have been unclear. Recently, either of two recurrent somatic missense mutations (G151R or L168R was found in the potassium channel KCNJ5 gene in aldosterone producing adenomas. These mutations alter the channel selectivity filter and result in Na(+ conductance and cell depolarization, stimulating aldosterone production and cell proliferation. Because a similar mutation occurs in a mendelian form of primary aldosteronism, these mutations appear to be sufficient for cell proliferation and aldosterone production. The prevalence and spectrum of KCNJ5 mutations in different entities of adrenocortical lesions remain to be defined. MATERIALS AND METHODS: The coding region and flanking intronic segments of KCNJ5 were subjected to Sanger DNA sequencing in 351 aldosterone producing lesions, from patients with primary aldosteronism and 130 other adrenocortical lesions. The specimens had been collected from 10 different worldwide referral centers. RESULTS: G151R or L168R somatic mutations were identified in 47% of aldosterone producing adenomas, each with similar frequency. A previously unreported somatic mutation near the selectivity filter, E145Q, was observed twice. Somatic G151R or L168R mutations were also found in 40% of aldosterone producing adenomas associated with marked hyperplasia, but not in specimens with merely unilateral hyperplasia. Mutations were absent in 130 non-aldosterone secreting lesions. KCNJ5 mutations were overrepresented in aldosterone producing adenomas from female compared to male patients (63 vs. 24%. Males with KCNJ5 mutations were significantly younger than those without (45 vs. 54, respectively; p<0.005 and their APAs with KCNJ5 mutations were larger than those without (27.1 mm vs. 17.1 mm; p<0.005. DISCUSSION: Either of two somatic KCNJ5 mutations are highly prevalent and specific for aldosterone producing

  12. A novel role of sesamol in inhibiting NF-κB-mediated signaling in platelet activation

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    Chang Chao-Chien

    2011-12-01

    Full Text Available Abstract Background Platelet activation is relevant to a variety of coronary heart diseases. Our previous studies revealed that sesamol possesses potent antiplatelet activity through increasing cyclic AMP formation. Although platelets are anucleated cells, they also express the transcription factor, NF-κB, that may exert non-genomic functions in platelet activation. Therefore, we further investigated the inhibitory roles of sesamol in NF-κB-mediated platelet function. Methods Platelet aggregation, Fura 2-AM fluorescence, and immunoblotting analysis were used in this study. Results NF-κB signaling events, including IKKβ phosphorylation, IκBα degradation, and p65 phosphorylation, were markedly activated by collagen (1 μg/ml in washed human platelets, and these signaling events were attenuated by sesamol (2.5~25 μM. Furthermore, SQ22536 and ODQ, inhibitors of adenylate cyclase and guanylate cyclase, respectively, strongly reversed the sesamol (25 μM-mediated inhibitory effects of IKKβ phosphorylation, IκBα degradation, and p65 phosphorylation stimulated by collagen. The protein kinase A (PKA inhibitor, H89, also reversed sesamol-mediated inhibition of IκBα degradation. Moreover, BAY11-7082, an NF-κB inhibitor, abolished IκBα degradation, phospholipase C (PLCγ2 phosphorylation, protein kinase C (PKC activation, [Ca2+]i mobilization, and platelet aggregation stimulated by collagen. Preincubation of platelets with the inhibitors, SQ22536 and H89, both strongly reversed sesamol-mediated inhibition of platelet aggregation and [Ca2+]i mobilization. Conclusions Sesamol activates cAMP-PKA signaling, followed by inhibition of the NF-κB-PLC-PKC cascade, thereby leading to inhibition of [Ca2+]i mobilization and platelet aggregation. Because platelet activation is not only linked to hemostasis, but also has a relevant role in inflammation and metastasis, our data demonstrating that inhibition of NF-κB interferes with platelet function may

  13. Effects of treatment with β-blocker and aldosterone antagonist on central and peripheral haemodynamics and oxygenation in cirrhosis

    DEFF Research Database (Denmark)

    Winkler, Christine; Hobolth, Lise; Krag, Aleksander;

    2011-01-01

    Patients with cirrhosis often exhibit abnormalities in cardiovascular regulation and oxygenation. Many of these patients are treated with β-blockers and aldosterone antagonists that may influence the regulation of systemic haemodynamics, but the specific effects on systemic haemodynamics and...

  14. Src mediates the mechanical activation of myogenesis by activating TNFα-converting enzyme

    OpenAIRE

    Niu, Airu; Wen, Yefei; Liu, Huijie; Zhan, Mei; Jin, Bingwen; Li, Yi-Ping

    2013-01-01

    Mechanical stimulation affects many biological aspects in living cells through mechanotransduction. In myogenic precursor cells (MPCs), mechanical stimulation activates p38 mitogen-activated protein kinase (MAPK), a key regulator of myogenesis, via activating TNFα-converting enzyme (TACE, also known as ADAM17), to release autocrine TNFα. However, the signaling mechanism of mechanical activation of TACE is unknown. Because TACE possesses the structural features of substrates of the non-recepto...

  15. Determination of the Aldosterone/Plasma Renin Activity Ratio for the Screening of Primary Hyperaldosteronism in Essential Hypertension: a Multicentric Study Determinación del valor de corte de la relación aldosterona/actividad de renina plasmática para la detección de hiperaldosteronismo primario en hipertensión arterial esencial: estudio multicéntrico

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    E Pardes

    2010-06-01

    Full Text Available Primary hyperaldosteronism (PHA or Conn's disease was classically suspected in the presence of hypertension (H and hypokalemia. It was previously considered as a rare cause of H, being reported in only 1% of hypertensive patients. It can be caused by an adrenal adenoma (the former usual presentation or by adrenal hyperplasia. But since the use of the aldosterone/plasma renin activity ratio (AAR as the screening method in the last years, it is currently considered as almost the most frequent cause of secondary H., accounting for 5-10% of essential H. Plasma rennin activity (PRA determination is a laborious procedure with low reproducibility and it directly affects the AAR; thus each laboratory must assess its own cut-off value. Therefore, in the Adrenal Department of the Argentine Society of Endocrinology and Metabolism (SAEM, we performed this multicentric prospective study of a population of Argentina with the aim of assessing our own AAR cut-off level in normotensive controls in order to apply it for PHA screening in essential hypertensive patients. We studied 353 adult subjects: 104 controls, aged 45,18 ± 13,78 years-old ( X±SD, with no history of arterial hypertension in their first-degree relatives and with two separate day-registry of blood pressure≤ 139/85 mmHg and 249 hypertensive patients, aged 51± 13,6 years-old ( X ± SD, with arterial blood pressure≥ 140/90 mmHg in the sitting position. Subjects with cardiac, renal, hepatic and neurological diseases were excluded as well as those with Cushing´s syndrome, hyperthyroidism, untreated hypothyroidism, diabetes mellitus and patients under glucocorticoids, oral contraceptive pills or estrogen therapy. A normal sodium diet was indicated and potassium was supplemented when needed. Blood was withdrawn between 8 and 10:00 a.m. with the subjects in the upright position. Aldosterone (A was determined by DPC radioimmunoassay (RIA and PRA, by DIA-Sorin RIA. The A normal levels are 4-30 ng

  16. Aldosterone inhibits the fetal program and increases hypertrophy in the heart of hypertensive mice.

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    Feriel Azibani

    Full Text Available 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

  17. Renin-aldosterone and kallikrein-kinin systems in the patients with arterial hypertension who took part in elimination of aftereffects of the accident at Chernobyl Atomic Power Station

    International Nuclear Information System (INIS)

    The study involved 290 patients with arterial hypertension (borderline arterial hypertension, stage 1 and 2 hypertensive disease) who took part in elimination of the aftereffects of the accident at Chernobyl Atomic Power Station (liquidators). The values of pressor renin-aldosterone system and depressor kallikrein-kinin system were determined in the patients. Some peculiarities of vasoactive regulation in these patients were established. Low-renin forms of arterial hypertension are characteristic for the examined liquidators.Irrespective of the stage of hypertension development and renin activity level, increased amount of plasma aldosterone was observed in the liquidators, which can suggest of primary aldosteronism in some patients with low level of renin. Absence of activation and even exhaustion of depressor system (kallikrein-kinin) was revealed in the examined liquidators, which is not characteristic for the patients of the same age who were not exposed to ionizing radiation. The revealed changes of vasoactive regulation in the liquidators with arterial hypertension of comparatively young age have already been described for elderly and old persons and can suggest of aging rate increase in this group of patients

  18. Integrin-mediated adhesion as self-sustained waves of enzymatic activation.

    Science.gov (United States)

    Block, M R; Destaing, O; Petropoulos, C; Planus, E; Albigès-Rizo, C; Fourcade, B

    2015-10-01

    Integrin receptors mediate interaction between the cellular actin-cytoskeleton and extracellular matrix. Based on their activation properties, we propose a reaction-diffusion model where the kinetics of the two-state receptors is modulated by their lipidic environment. This environment serves as an activator variable, while a second variable plays the role of a scaffold protein and controls the self-sustained activation of the receptors. Due to receptor diffusion which couples dynamically the activator and the inhibitor, our model connects major classes of reaction diffusion systems for excitable media. Spot and rosette solutions, characterized by receptor clustering into localized static or dynamic structures, are organized into a phase diagram. It is shown that diffusion and kinetics of receptors determines the dynamics and the stability of these structures. We discuss this model as a precursor model for cell signaling in the context of podosomes forming actoadhesive metastructures, and we study how generic signaling defects influence their organization. PMID:26565269

  19. Nitric oxide mediates increased P-glycoprotein activity in interferon-{gamma}-stimulated human intestinal cells.

    Science.gov (United States)

    Dixit, Santosh G; Zingarelli, Basilia; Buckley, Donna J; Buckley, Arthur R; Pauletti, Giovanni M

    2005-03-01

    Patients with refractory inflammatory bowel disease (IBD) exhibit increased expression of intestinal P-glycoprotein (P-gp) as well as elevated luminal IFN-gamma and nitric oxide (NO) levels. Using the in vitro Caco-2 cell culture model, we investigated whether these pathological mediators associated with the etiology of IBD affect functional activity of intestinal efflux systems. IFN-gamma reduced cellular uptake of cyclosporin A (CysA) but not methotrexate (MTX) in a time- and concentration-dependent manner. Simultaneously, P-gp expression increased by approximately twofold. Coincubation with the inducible NO synthase inhibitor l-N(6)-(1-iminoethyl)lysine (l-NIL) dramatically reduced production of intracellular NO in response to IFN-gamma stimulus. The presence of l-NIL also abrogated the cytokine-mediated increase in P-gp expression and function suggesting that NO is required for IFN-gamma-mediated activation of this efflux system. Exposure of Caco-2 cells to the chemical NO donor S-nitroso-N-acetylpenicillamine (SNAP) produced a concentration-dependent decrease in intracellular CysA accumulation that was paralleled by an increase in P-gp expression. Both IFN-gamma and SNAP enhanced DNA binding of NF-kappaB, whereas inclusion of l-NIL dramatically decreased this cytokine-induced effect on NF-kappaB binding. These results suggest that NO mediates IFN-gamma-induced increase in expression and function of intestinal P-gp in the human Caco-2 cell culture model by altering DNA binding of NF-kappaB, which may enhance transcription of the ABCB1 gene encoding for this efflux system. PMID:15486347

  20. Single-port laparoscopic adrenalectomy for a right-sided aldosterone-producing adenoma: a case report

    OpenAIRE

    Sasaki Akira; Baba Shigeaki; Obuchi Toru; Umemura Akira; Mizuno Masaru; Wakabayashi Go

    2012-01-01

    Abstract Introduction Single-port laparoscopic adrenalectomy is one of the most interesting surgical advances. Here, we evaluate the safety and feasibility of single-port laparoscopic adrenalectomy as treatment for a right-sided aldosterone-producing adenoma. Case presentation A 39-year-old Japanese woman presented with hypertension and hypokalemia. Abdominal computed tomography and an endocrinological workup revealed a 19mm right adrenal tumor with primary aldosteronism. Our patient was info...

  1. PPAR-γ activation by Tityus serrulatus venom regulates lipid body formation and lipid mediator production.

    Science.gov (United States)

    Zoccal, Karina Furlani; Paula-Silva, Francisco Wanderley Garcia; Bitencourt, Claudia da Silva; Sorgi, Carlos Artério; Bordon, Karla de Castro Figueiredo; Arantes, Eliane Candiani; Faccioli, Lúcia Helena

    2015-01-01

    Tityus serrulatus venom (TsV) consists of numerous peptides with different physiological and pharmacological activities. Studies have shown that scorpion venom increases pro-inflammatory cytokine production, contributing to immunological imbalance, multiple organ dysfunction, and patient death. We have previously demonstrated that TsV is a venom-associated molecular pattern (VAMP) recognized by TLRs inducing intense inflammatory reaction through the production of pro-inflammatory cytokines and arachidonic acid-derived lipid mediators prostaglandin (PG)E2 and leukotriene (LT)B4. Lipid bodies (LBs) are potential sites for eicosanoid production by inflammatory cells. Moreover, recent studies have shown that the peroxisome proliferator-activated receptor gamma (PPAR-γ) is implicated in LB formation and acts as an important modulator of lipid metabolism during inflammation. In this study, we used murine macrophages to evaluate whether the LB formation induced by TsV after TLR recognition correlates with lipid mediator generation by macrophages and if it occurs through PPAR-γ activation. We demonstrate that TsV acts through TLR2 and TLR4 stimulation and PPAR-γ activation to induce LB formation and generation of PGE2 and LTB4. Our data also show that PPAR-γ negatively regulates the pro-inflammatory NF-κB transcription factor. Based on these results, we suggest that during envenomation, LBs constitute functional organelles for lipid mediator production through signaling pathways that depend on cell surface and nuclear receptors. These findings point to the inflammatory mechanisms that might also be triggered during human envenomation by TsV. PMID:25450800

  2. Moms in motion: a group-mediated cognitive-behavioral physical activity intervention

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    Brawley Lawrence R

    2006-08-01

    Full Text Available Abstract Background When examining the prevalence of physical inactivity by gender and age, women over the age of 25 are at an increased risk for sedentary behavior. Childbearing and motherhood have been explored as one possible explanation for this increased risk. Post natal exercise studies to date demonstrate promising physical and psychological outcomes, however few physical activity interventions have been theory-driven and tailored to post natal exercise initiates. The purpose of this study was to compare the effects of a group-mediated cognitive behavioral intervention based upon social-cognitive theory and group dynamics (GMCB to a standard care postnatal exercise program (SE. Method A randomized, two-arm intervention design was used. Fifty-seven post natal women were randomized to one of two conditions: (1 a standard exercise treatment (SE and (2 a standard exercise treatment plus group-mediated cognitive behavioral intervention (GMCB. Participants in both conditions participated in a four-week intensive phase where participants received standard exercise training. In addition, GMCB participants received self-regulatory behavioral skills training via six group-mediated counseling sessions. Following the intensive phase, participants engaged in a four-week home-based phase of self-structured exercise. Measures of physical activity, barrier efficacy, and proximal outcome expectations were administered and data were analyzed using ANCOVA procedures. Results and discussion ANCOVA of change scores for frequency, minutes, and volume of physical activity revealed significant treatment effects over the intensive and home-based phases (p's Conclusion While both exercise programs resulted in improvements to exercise participation, the GMCB intervention produced greater improvement in overall physical activity, barrier efficacy and proximal outcome expectations.

  3. Regulation of ENaC-Mediated Sodium Reabsorption by Peroxisome Proliferator-Activated Receptors

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    Tengis S. Pavlov

    2010-01-01

    Full Text Available Peroxisome proliferator-activated receptors (PPARs are members of a steroid hormone receptor superfamily that responds to changes in lipid and glucose homeostasis. Peroxisomal proliferator-activated receptor subtype γ (PPARγ has received much attention as the target for antidiabetic drugs, as well as its role in responding to endogenous compounds such as prostaglandin J2. However, thiazolidinediones (TZDs, the synthetic agonists of the PPARγ are tightly associated with fluid retention and edema, as potentially serious side effects. The epithelial sodium channel (ENaC represents the rate limiting step for sodium absorption in the renal collecting duct. Consequently, ENaC is a central effector impacting systemic blood volume and pressure. The role of PPARγ agonists on ENaC activity remains controversial. While PPARγ agonists were shown to stimulate ENaC-mediated renal salt absorption, probably via Serum- and Glucocorticoid-Regulated Kinase 1 (SGK1, other studies reported that PPARγ agonist-induced fluid retention is independent of ENaC activity. The current paper provides new insights into the control and function of ENaC and ENaC-mediated sodium transport as well as several other epithelial channels/transporters by PPARs and particularly PPARγ. The potential contribution of arachidonic acid (AA metabolites in PPAR-dependent mechanisms is also discussed.

  4. Hydrogen peroxide mediates Rac1 activation of S6K1

    International Nuclear Information System (INIS)

    We previously reported that hydrogen peroxide (H2O2) mediates mitogen activation of ribosomal protein S6 kinase 1 (S6K1) which plays an important role in cell proliferation and growth. In this study, we investigated a possible role of H2O2 as a molecular linker in Rac1 activation of S6K1. Overexpression of recombinant catalase in NIH-3T3 cells led to the drastic inhibition of H2O2 production by PDGF, which was accompanied by a decrease in S6K1 activity. Similarly, PDGF activation of S6K1 was significantly inhibited by transient transfection or stable transfection of the cells with a dominant-negative Rac1 (Rac1N17), while overexpression of constitutively active Rac1 (Rac1V12) in the cells led to an increase in basal activity of S6K1. In addition, stable transfection of Rat2 cells with Rac1N17 dramatically attenuated the H2O2 production by PDGF as compared with that in the control cells. In contrast, Rat2 cells stably transfected with Rac1V12 produced high level of H2O2 in the absence of PDGF, comparable to that in the control cells stimulated with PDGF. More importantly, elimination of H2O2 produced in Rat2 cells overexpressing Rac1V12 inhibited the Rac1V12 activation of S6K1, indicating the possible role of H2O2 as a mediator in the activation of S6K1 by Rac1. However, H2O2 could be also produced via other pathway, which is independent of Rac1 or PI3K, because in Rat2 cells stably transfected with Rac1N17, H2O2 could be produced by arsenite, which has been shown to be a stimulator of H2O2 production. Taken together, these results suggest that H2O2 plays a pivotal role as a mediator in Rac1 activation of S6K1

  5. Does Pedestrian Danger Mediate the Relationship between Local Walkability and Active Travel to Work?

    Directory of Open Access Journals (Sweden)

    Sandy J Slater

    2016-05-01

    Full Text Available Background: Environmental and policy factors play an important role in influencing people’s lifestyles, physical activity (PA, and risks for developing obesity. Research suggests that more walkable communities are needed to sustain lifelong PA behavior, but there is a need to determine what local built environment features facilitate making being active the easy choice.Purpose: This county-level study examined the association between local walkability (walkability and traffic calming scales, pedestrian danger, and the percent of adults who used active transport to work. Methods: Built environment and PA outcome measures were constructed for the 496 most populous counties representing 74 percent of the U.S. population. GIS-based walkability scales were constructed and include a census of roads located within the counties using 2011 Navteq data. The pedestrian danger index (PDI includes data collected from the Fatality Analysis Reporting System 2009-2011, and measures the likelihood of a pedestrian being hit and killed by a vehicle. Four continuous outcome measures were constructed using 2009-2013 American Community Survey county-level 5-year estimates. The measures represent the percentage of workers living in a county who worked away from home and: 1 walked to work; 2 biked to work; 3 took public transit; and 4 used any form of active transport. Linear regression and mediation analyses were conducted to examine the association between walkability, PDI and active transport. Models accounted for clustering within state with robust standard errors, and controlled for median household income, families with children in poverty, race, ethnicity, urbanicity and region.Results: The walkability scale was significantly negatively associated with the PDI (β=-0.06, 95% CI=-0.111, -0.002. In all models, the PDI was significantly negatively associated with all active travel-related outcomes at the p<0.01 level. The walkability scale was positively

  6. Toll-like receptor 4 mediates microglial activation and production of inflammatory mediators in neonatal rat brain following hypoxia: role of TLR4 in hypoxic microglia

    OpenAIRE

    Yao Linli; Kan Enci Mary; Lu Jia; Hao Aijun; Dheen S Thameem; Kaur Charanjit; Ling Eng-Ang

    2013-01-01

    Abstract Background Hypoxia induces microglial activation which causes damage to the developing brain. Microglia derived inflammatory mediators may contribute to this process. Toll-like receptor 4 (TLR4) has been reported to induce microglial activation and cytokines production in brain injuries; however, its role in hypoxic injury remains uncertain. We investigate here TLR4 expression and its roles in neuroinflammation in neonatal rats following hypoxic injury. Methods One day old Wistar rat...

  7. Primary Aldosteronism: Changing Definitions and New Concepts of Physiology and Pathophysiology Both Inside and Outside the Kidney.

    Science.gov (United States)

    Stowasser, Michael; Gordon, Richard D

    2016-10-01

    In the 60 years that have passed since the discovery of the mineralocorticoid hormone aldosterone, much has been learned about its synthesis (both adrenal and extra-adrenal), regulation (by renin-angiotensin II, potassium, adrenocorticotrophin, and other factors), and effects (on both epithelial and nonepithelial tissues). Once thought to be rare, primary aldosteronism (PA, in which aldosterone secretion by the adrenal is excessive and autonomous of its principal regulator, angiotensin II) is now known to be the most common specifically treatable and potentially curable form of hypertension, with most patients lacking the clinical feature of hypokalemia, the presence of which was previously considered to be necessary to warrant further efforts towards confirming a diagnosis of PA. This, and the appreciation that aldosterone excess leads to adverse cardiovascular, renal, central nervous, and psychological effects, that are at least partly independent of its effects on blood pressure, have had a profound influence on raising clinical and research interest in PA. Such research on patients with PA has, in turn, furthered knowledge regarding aldosterone synthesis, regulation, and effects. This review summarizes current progress in our understanding of the physiology of aldosterone, and towards defining the causes (including genetic bases), epidemiology, outcomes, and clinical approaches to diagnostic workup (including screening, diagnostic confirmation, and subtype differentiation) and treatment of PA. PMID:27535640

  8. New approaches to hyperkalemia in patients with indications for renin angiotensin aldosterone inhibitors: Considerations for trial design and regulatory approval.

    Science.gov (United States)

    Zannad, Faiez; Rossignol, Patrick; Stough, Wendy Gattis; Epstein, Murray; Alonso Garcia, Maria de Los Angeles; Bakris, George L; Butler, Javed; Kosiborod, Mikhail; Berman, Lance; Mebazaa, Alexandre; Rasmussen, Henrik S; Ruilope, Luis M; Stockbridge, Norman; Thompson, Aliza; Wittes, Janet; Pitt, Bertram

    2016-08-01

    Hyperkalemia is a common clinical problem, especially in patients with chronic kidney disease, diabetes mellitus, or heart failure. Treatment with renin angiotensin aldosterone system inhibitors exacerbates the risk of hyperkalemia in these patients. Concern about hyperkalemia can result in the failure to initiate, suboptimal dosing, or discontinuation of renin angiotensin aldosterone system inhibitor therapy in patients; effective treatments for hyperkalemia might mitigate such undertreatment. New treatments for hyperkalemia in development may offer better efficacy, tolerability and safety profiles than do existing approved treatments. These compounds might enable more eligible patients to receive renin angiotensin aldosterone system inhibitor therapy or to receive renin angiotensin aldosterone system inhibitors at target doses. The evidence needed to support a treatment claim (reduction in serum potassium) differs from that needed to support a prevention claim (preventing hyperkalemia to allow renin angiotensin aldosterone system inhibitor treatment). Thus, several issues related to clinical trial design and drug development need to be considered. This paper summarizes and expands upon a discussion at the Global Cardiovascular Clinical Trialists 2014 Forum and examines methodologic considerations for trials of new potassium binders for the prevention and management of hyperkalemia in patients with renin angiotensin aldosterone system inhibitor indications. PMID:27140336

  9. Oxidative Conversion Mediates Antiproliferative Effects of tert-Butylhydroquinone: Structure and Activity Relationship Study.

    Science.gov (United States)

    Sanidad, Katherine Z; Sukamtoh, Elvira; Wang, Weicang; Du, Zheyuan; Florio, Ellie; He, Lili; Xiao, Hang; Decker, Eric A; Zhang, Guodong

    2016-05-18

    Previous studies have shown that tert-butylhydroquinone (TBHQ), a widely used food antioxidant, has cytotoxic effects at high doses; however, the underlying mechanisms are not well understood. Here, we found that the effects of TBHQ on cell proliferation, cell cycle progression, and apoptosis are mainly mediated by its oxidative conversion to a quinone metabolite tert-butylquinone (TBQ). Co-addition of cupric ion (Cu(2+)) caused accelerated oxidative conversion of TBHQ to TBQ and enhanced the biological activities of TBHQ on cell proliferation, cell cycle progression, and apoptosis in MC38 colon cancer cells. In contrast, co-addition of ethylenediaminetetraacetic acid (EDTA) suppressed TBHQ oxidation and inhibited the biological activities of TBHQ in MC38 cells. For example, after 24 h of treatment in basal medium, low-dose TBHQ (1.88-7.5 μM) had little effect on MC38 cell proliferation, while co-addition of 50 μM Cu(2+) caused 30-70% inhibition of cell proliferation; in contrast, treatment with high-dose TBHQ (15 μM) inhibited 50 ± 4% MC38 proliferation, which was abolished by co-addition of 50 μM EDTA. We further showed that TBQ had more potent actions on cell proliferation and associated cellular responses than TBHQ, supporting a critical role of TBQ formation in the biological activities of TBHQ. Finally, a structure and activity relationship study showed that the fast-oxidized para-hydroquinones had potent antiproliferative effects in MC38 cells, while the slow-oxidized para-hydroquinones had weak or little biological activities. Together, these results suggest that the biological activities of TBHQ and other para-hydroquinones are mainly mediated by their oxidative metabolism to generate more biologically active quinone metabolites. PMID:27111399

  10. Autonomy Mediates the Relationship between Personality and Physical Activity: An Application of Self-Determination Theory

    Directory of Open Access Journals (Sweden)

    Meredith L. Ramsey

    2016-04-01

    Full Text Available This study sought to examine tenets of Self-Determination Theory by testing a mediation model of physical activity and personality via autonomy. A total of 290 adults were recruited to complete a one-time online survey of exercise habits and individual characteristics. Surveys assessed personality, autonomy, and physical activity. A measurement model specifying direct effects between personality dimensions and physical activity and indirect effects operating through autonomy provided an excellent fit to the data (Χ2 = 0.66, df = 3, p = 0.88, RMSEA(90% CI = 0.00 (0.00–0.05, CFI = 0.99, SRMR = 0.01. Results indicated significant (p < 0.05 effects of Extroversion (β = 0.42, Conscientiousness (β = 0.96, and Emotional Stability (β = 0.60 on autonomy, which in turn, was significantly associated with physical activity (β = 0.55. No significant effects were observed for Agreeableness or Intellect. None of the personality constructs were found to be directly associated with physical activity. This model accounted for 27% of the variance in physical activity. The results of this study suggest that autonomy is significantly associated with physical activity. Therefore, attempts to improve autonomy in individuals may be a useful intervention strategy in improving physical activity levels.

  11. Effect of post-myocardial infarction exercise training on the renin-angiotensin-aldosterone system and cardiac function.

    Science.gov (United States)

    Wan, Wenhan; Powers, Anthony S; Li, Ji; Ji, Lisa; Erikson, John M; Zhang, John Q

    2007-10-01

    After a myocardial infarction (MI), the injured heart undergoes intensive remodeling characterized by activation of the circulating renin-angiotensin-aldosterone system (RAAS), left ventricular (LV) dilation, and contractile dysfunction. Exercise training may attenuate activation of the RAAS and improve myocardial remodeling. In this study, we investigated whether starting exercise training early or late after MI would have different effect on circulating RAAS and LV dilation and function. Male Sprague-Dawley rats (7 weeks old) underwent surgically induced MI. After surgery, rats were matched for similar infarct sizes and assigned into two major groups, based on the designated starting time of exercise training. Exercise groups started exercise at either 1 or 6 weeks after MI and exercised on a treadmill for 8 weeks. Groups starting exercise 1 week after MI included sham-operated control (1Wk-Sham), MI-ksedentary (1Wk-MI-Sed), and MI-exercise (1Wk-MI-Ex). Groups starting exercise 6 weeks after MI included sham-operated control (6Wk-Sham), MI-sedentary (6Wk-MI-Sed), and MI-exercise (6Wk-MI-Ex). An echocardiogram was performed before and after exercise training. Blood samples were obtained at the end of experiments. The results showed that compared with sedentary rats with MI, exercise training significantly attenuated circulating renin, angiotensin converting enzyme, angiotensin II, and aldosterone. Rats in exercise groups had similar LV end-diastolic diameters compared with their sedentary counterparts and tended to have smaller LV end-systolic diameters, and percent fractional shortening in exercise rats was significantly higher than in sedentary rats. These findings suggest that exercise training does not cause LV dilation and preserves LV function. Post-MI exercise training also normalizes the circulating RAAS, and this effect is independent of timing of post-MI exercise. Exercise starting early or late after MI affects myocardial remodeling and function

  12. Aromatic Cyanoalkylation through Double C-H Activation Mediated by Ni(III).

    Science.gov (United States)

    Zhou, Wen; Zheng, Shuai; Schultz, Jason W; Rath, Nigam P; Mirica, Liviu M

    2016-05-11

    Herein we report an atom- and step-economic aromatic cyanoalkylation reaction that employs nitriles as building blocks and proceeds through Csp(2)-H and Csp(3)-H bond activation steps mediated by Ni(III). In addition to cyanomethylation with MeCN, regioselective α-cyanoalkylation was observed with various nitrile substrates to generate secondary and tertiary nitriles. Importantly, to the best of our knowledge these are the first examples of C-H bond activation reactions occurring at a Ni(III) center, which may exhibit different reactivity and selectivity profiles than those corresponding to analogous Ni(II) centers. These studies provide guiding principles to design catalytic C-H activation and functionalization reactions involving high-valent Ni species. PMID:27120207

  13. Diagnostic Value of I-131 NP-59 SPECT/CT Scintigraphy in Patients with Subclinical or Atypical Features of Primary Aldosteronism

    Directory of Open Access Journals (Sweden)

    Yi-Chun Chen

    2011-01-01

    Full Text Available Accumulating evidence has shown the adverse effect of long-term hyperaldosteronism on cardiovascular morbidity that is independent of blood pressure. However, the diagnosis of primary aldosteronism (PA remains a challenge for patients who present with subtle or atypical features or have chronic kidney disease (CKD. SPECT/CT has proven valuable in the diagnosis of a number of conditions. The aim of this study was to determine the usefulness of I-131 NP-59 SPECT/CT in patients with atypical presentations of PA and in those with CKD. The records of 15 patients with PA were retrospectively analyzed. NP-59 SPECT/CT was able to identify adrenal lesion(s in CKD patients with suspected PA. Patients using NP-59 SPECT/CT imaging, compared with those not performing this procedure, significantly featured nearly normal serum potassium levels, normal aldosterone-renin ratio, and smaller adrenal size on CT and pathological examination and tended to feature stage 1 hypertension and non-suppressed plasma renin activity. These findings show that noninvasive NP-59 SPECT/CT is a useful tool for diagnosis in patients with subclinical or atypical features of PA and those with CKD.

  14. Platelet and monocyte activity markers and mediators of inflammation in Takotsubo cardiomyopathy.

    Science.gov (United States)

    Pirzer, Rainer; Elmas, Elif; Haghi, Dariusch; Lippert, Christiane; Kralev, Stefan; Lang, Siegfried; Borggrefe, Martin; Kälsch, Thorsten

    2012-03-01

    Patients with Takotsubo cardiomyopathy (TC) often present with symptoms similar to those of myocardial infarction (MI). We analyzed blood concentrations of mediators of inflammation and platelet- and monocyte-activity markers in patients with TC and MI for significant differences. Clinical data of patients with TC (n = 16) and acute MI (n = 16) were obtained. Serial blood samples were taken at the time of hospital admission (t(0)), after 2-4 days (t(1)) and after 4-7 weeks (t(2)), respectively. Plasma concentrations of interleukin (IL)-6, IL-7, soluble CD40 ligand (sCD40L), and monocyte chemotactic protein 1 (MCP-1) were determined with an ELISA. Tissue factor binding on monocytes, platelet-activation marker CD62P, platelet CD40-ligand (CD40L), and platelet-monocyte aggregates were measured using flow cytometry. Expression of CD62P on platelets and IL-6 plasma levels were significantly lower in patients with TC compared to MI at the time of hospital admission. IL-7 plasma levels were significantly elevated in patients with TC compared to patients with MI at 2-4 days after hospital admission. No significant differences were observed concerning sCD40L and MCP-1 plasma levels, tissue factor binding on monocytes, CD40L expression on platelets, and platelet-monocyte aggregates at any point in time. Our results indicate that inflammatory mediators and platelet-activity markers contribute to the differences in the pathogenesis of MI and TC. PMID:21416113

  15. EMT phenotype is induced by increased Src kinase activity via Src-mediated caspase-8 phosphorylation.

    Science.gov (United States)

    Zhao, Yang; Li, XiaoJun; Sun, XiangFei; Zhang, YunFeng; Ren, Hong

    2012-01-01

    Caspase-8 governs multiple cell responses to the microenvironmental cues. However, its integration of "death-life" signalings remains elusive. In our study, the role of caspase-8-Src is well-established as a promoter for migration or metastasis in Casp8(+)Src(+) A549/H226 cells in vivo and in vitro. In particular for nude mice models, mice implanted with Casp8(+)Src(+) A459/H226 cells remarkably increased spontaneous tumor metastatic burden with a significant survival disadvantage. Additionally, we detect that Src-mediated caspase-8 phosphorylation stimulates Src phosphorylation at Tyr-416 via the linkage of Src SH2 domain with phosph-Tyr-380 site of caspase-8. In turn, activated Src can efficiently induce epithelial-mesenchymal transition (EMT) phenotypic features to promote tumor cells metastasis. Surprisingly, RXDLL motif deletion in the DEDa of caspase-8 attenuates tumor cell migration or metastasis via impairing the recruitment of caspase-8 into the cellular periphery where activated Src is subject to caspase-8 phosphorylation. Together, a simple model is that the peripherization of caspase-8 is well-poised to facilitate Src-mediated caspase-8 phosphrylation at Tyr-380, then binding of phospho-Tyr380 of caspase-8 to Src SH2 domain may maintain Src in an active conformation to induce EMT phenotype, a key step toward cancer metastasis. PMID:22508042

  16. Activation of band 3 mediates group A Streptococcus streptolysin S-based beta-haemolysis.

    Science.gov (United States)

    Higashi, Dustin L; Biais, Nicolas; Donahue, Deborah L; Mayfield, Jeffrey A; Tessier, Charles R; Rodriguez, Kevin; Ashfeld, Brandon L; Luchetti, Jeffrey; Ploplis, Victoria A; Castellino, Francis J; Lee, Shaun W

    2016-01-01

    Streptococcus pyogenes, or group A Streptococcus (GAS), is a human bacterial pathogen that can manifest as a range of diseases from pharyngitis and impetigo to severe outcomes such as necrotizing fasciitis and toxic shock syndrome. GAS disease remains a global health burden with cases estimated at over 700 million annually and over half a million deaths due to severe infections(1). For over 100 years, a clinical hallmark of diagnosis has been the appearance of complete (beta) haemolysis when grown in the presence of blood. This activity is due to the production of a small peptide toxin by GAS known as streptolysin S. Although it has been widely held that streptolysin S exerts its lytic activity through membrane disruption, its exact mode of action has remained unknown. Here, we show, using high-resolution live cell imaging, that streptolysin S induces a dramatic osmotic change in red blood cells, leading to cell lysis. This osmotic change was characterized by the rapid influx of Cl(-) ions into the red blood cells through SLS-mediated disruption of the major erythrocyte anion exchange protein, band 3. Chemical inhibition of band 3 function significantly reduced the haemolytic activity of streptolysin S, and dramatically reduced the pathology in an in vivo skin model of GAS infection. These results provide key insights into the mechanism of streptolysin S-mediated haemolysis and have implications for the development of treatments against GAS. PMID:27571972

  17. A conserved patch of hydrophobic amino acids modulates Myb activity by mediating protein-protein interactions.

    Science.gov (United States)

    Dukare, Sandeep; Klempnauer, Karl-Heinz

    2016-07-01

    The transcription factor c-Myb plays a key role in the control of proliferation and differentiation in hematopoietic progenitor cells and has been implicated in the development of leukemia and certain non-hematopoietic tumors. c-Myb activity is highly dependent on the interaction with the coactivator p300 which is mediated by the transactivation domain of c-Myb and the KIX domain of p300. We have previously observed that conservative valine-to-isoleucine amino acid substitutions in a conserved stretch of hydrophobic amino acids have a profound effect on Myb activity. Here, we have explored the function of the hydrophobic region as a mediator of protein-protein interactions. We show that the hydrophobic region facilitates Myb self-interaction and binding of the histone acetyl transferase Tip60, a previously identified Myb interacting protein. We show that these interactions are affected by the valine-to-isoleucine amino acid substitutions and suppress Myb activity by interfering with the interaction of Myb and the KIX domain of p300. Taken together, our work identifies the hydrophobic region in the Myb transactivation domain as a binding site for homo- and heteromeric protein interactions and leads to a picture of the c-Myb transactivation domain as a composite protein binding region that facilitates interdependent protein-protein interactions of Myb with regulatory proteins. PMID:27080133

  18. 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.

    Science.gov (United States)

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

    2016-02-01

    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. PMID:26802905

  19. 5-Azacytidine Promotes an Inhibitory T-Cell Phenotype and Impairs Immune Mediated Antileukemic Activity

    OpenAIRE

    Thomas Stübig; Anita Badbaran; Tim Luetkens; York Hildebrandt; Djordje Atanackovic; Binder, Thomas M. C.; Boris Fehse; Nicolaus Kröger

    2014-01-01

    Demethylating agent, 5-Azacytidine (5-Aza), has been shown to be active in treatment of myeloid malignancies. 5-Aza enhances anticancer immunity, by increasing expression of tumor-associated antigens. However, the impact of 5-Aza immune responses remains poorly understood. Here, T-cell mediated tumor immunity effects of 5-Aza, are investigated in vitro and in vivo. T-cells from healthy donors were treated with 5-Aza and analyzed by qRT-PCR and flow cytometry for changes in gene expression and...

  20. School site walkability and active school transport - association, mediation and moderation

    DEFF Research Database (Denmark)

    Breum, Lars; Toftager, M.; Schipperijn, J.; Ersbøll, A.K.; Giles-Corti, B.; Troelsen, J.

    2014-01-01

    Increasing active school transport (AST) can improve population health, but its association with the urban form is not fully clear. This study investigated the association of an objective school walkability index with AST and how this association is mediated by the perceived physical and social...... walkability index was significantly associated with AST (Medium vs. Low OR 2.68; High vs. Low OR 2.49). Adding the perceived physical and social environment variables improved the model prediction of AST, with no change in the association with the school walkability index. Furthermore, distance to school...

  1. Aldosterone-Induced Inflammation in the Rat Heart : Role of Oxidative Stress

    OpenAIRE

    Sun, Yao; Zhang, Jiakun; Lu, Li; Chen, Sue S.; Quinn, Mark T.; Weber, Karl T.

    2002-01-01

    Heart failure and hypertension have each been linked to an induction of oxidative stress transduced by neurohormones, such as angiotensin II and catecholamines. Herein, we hypothesized that aldosterone (ALDO) likewise induces oxidative stress and accounts for a proinflammatory/fibrogenic phenotype that appears at vascular and nonvascular sites of injury found in both right and left ventricles in response to ALDO/salt treatment and that would be sustained with chronic treatment. Uninephrectomi...

  2. Association of KCNJ5 gene missense mutations with aldosterone-producing adenoma and primary hyperaldosteronism

    Institute of Scientific and Technical Information of China (English)

    邵丹

    2013-01-01

    Objective To detect the KCNJ5 gene variations in aldosterone-producing adenoma (APA) with primary hyperaldosteronism (PA) ,and to investigate the association of the KCNJ5 gene missense mutations with APA and PA.Methods A total of 46 APA tumors and their clinical characteristics were collected from Hypertension Center of the People’s Hospital of Xinjiang Uygur Autonomous Region,and all the tumors were confirmed by pathology.

  3. Effect of deafferentation of the rat tongue on plasma corticosterone, aldosterone, angiotensin and ACTH levels

    International Nuclear Information System (INIS)

    The effect of deafferentation of the tongue on the plasma level of hormones involved in regulation of the sodium ion level -- aldosterone, corticosterone, ACTH, and angiotensin -- was studied. Plasma hormone levels were determined by radioimmunoassay. The results indicate the important role of orosensory and taste perception in the processes of regulation of the sodium balance in the body. The experiments in this study were conducted on rats

  4. Dual role of Med12 in PRC1-dependent gene repression and ncRNA-mediated transcriptional activation.

    Science.gov (United States)

    Papadopoulou, Thaleia; Kaymak, Aysegül; Sayols, Sergi; Richly, Holger

    2016-06-01

    Mediator is considered an enhancer of RNA-Polymerase II dependent transcription but its function and regulation in pluripotent mouse embryonic stem cells (mESCs) remains unresolved. One means of controlling the function of Mediator is provided by the binding of the Cdk8 module (Med12, Cdk8, Ccnc and Med13) to the core Mediator. Here we report that Med12 operates together with PRC1 to silence key developmental genes in pluripotency. At the molecular level, while PRC1 represses genes it is also required to assemble ncRNA containing Med12-Mediator complexes. In the course of cellular differentiation the H2A ubiquitin binding protein Zrf1 abrogates PRC1-Med12 binding and facilitates the association of Cdk8 with Mediator. This remodeling of Mediator-associated protein complexes converts Mediator from a transcriptional repressor to a transcriptional enhancer, which then mediates ncRNA-dependent activation of Polycomb target genes. Altogether, our data reveal how the interplay of PRC1, ncRNA and Mediator complexes controls pluripotency and cellular differentiation. PMID:27096886

  5. Ambulatory Blood Pressure Monitoring-Derived Short-Term Blood Pressure Variability in Primary Aldosteronism.

    Science.gov (United States)

    Grillo, Andrea; Bernardi, Stella; Rebellato, Andrea; Fabris, Bruno; Bardelli, Moreno; Burrello, Jacopo; Rabbia, Franco; Veglio, Franco; Fallo, Francesco; Carretta, Renzo

    2015-08-01

    The aim of this study was to investigate the short-term blood pressure (BP) variability (BPV) derived from ambulatory blood pressure monitoring (ABPM) in patients with primary aldosteronism (PA), either idiopathic hyperaldosteronism (IHA) or aldosterone-producing adenoma (APA), in comparison with patients with essential hypertension (EH) and normotensive (NT) controls. Thirty patients with PA (16 with IHA and 14 with APA), 30 patients with EH, and 30 NT controls, matched for sex, age, body mass index, and antihypertensive therapy, were studied. The standard deviation (SD) of 24-hour, daytime, and nighttime BP; 24-hour weighted SD of BP; and 24-hour BP average real variability were not different between patients with PA and those with EH (P=not significant). All BPV indices were higher in patients with PA, either IHA or APA subtypes, and patients with EH, compared with NT controls (P<.001 to P<.05). ABPM-derived short-term BPV is increased in patients with PA, and it may represent an additional cardiovascular risk factor in this disease. The role of aldosterone excess in BPV has to be clarified. PMID:25880017

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

    International Nuclear Information System (INIS)

    11β-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 11β-hydroxylase and the other encoding aldosterone synthase (CYP11B2), were isolated 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

  7. Development of CpG-oligodeoxynucleotides for effective activation of rabbit TLR9 mediated immune responses.

    Directory of Open Access Journals (Sweden)

    Tsung-Hsien Chuang

    Full Text Available CpG-oligodeoxynucleotides (CpG-ODN are potent immune stimuli being developed for use as adjuvants in different species. Toll-like receptor 9 (TLR9 is the cellular receptor for CpG-ODN in mammalian cells. The CpG-ODN with 18-24 deoxynucleotides that are in current use for human and mouse cells, however, have low activity with rabbit TLR9. Using a cell-based activation assay, we developed a type of CpG-ODN containing a GACGTT or AACGTT motif in 12 phosphorothioate-modified deoxynucleotides with potent stimulatory activity for rabbit TLR9. The developed CpG-ODN have higher activities than other developed CpG-ODN in eliciting antigen-nonspecific immune responses in rabbit splenocytes. When mixed with an NJ85 peptide derived from rabbit hemorrhagic disease virus, they had potent activities to boost an antigen-specific T cell activation and antibody production in rabbits. Compared to Freund's adjuvant, the developed CpG-ODN are capable of boosting a potent and less toxic antibody response. The results of this study suggest that both the choice of CpG-motif and its length are important factors for CpG-ODN to effectively activate rabbit TLR9 mediated immune responses.

  8. Human breast cancer cell-mediated bone collagen degradation requires plasminogen activation and matrix metalloproteinase activity

    Directory of Open Access Journals (Sweden)

    Hill Peter A

    2005-02-01

    Full Text Available Abstract Background Breast cancer cells frequently metastasize to the skeleton and induce extensive bone destruction. Cancer cells produce proteinases, including matrix metalloproteinases (MMPs and the plasminogen activator system (PAS which promote invasion of extracellular matrices, but whether these proteinases degrade bone matrix is unclear. To characterize the role that breast cancer cell proteinases play in bone degradation we compared the effects of three human breast cancer cell lines, MDA-MB-231, ZR-75-1 and MCF-7 with those of a normal breast epithelial cell line, HME. The cell lines were cultured atop radiolabelled matrices of either mineralized or non-mineralized bone or type I collagen, the principal organic constituent of bone. Results The 3 breast cancer cell lines all produced significant degradation of the 3 collagenous extracellular matrices (ECMs whilst the normal breast cell line was without effect. Breast cancer cells displayed an absolute requirement for serum to dissolve collagen. Degradation of collagen was abolished in plasminogen-depleted serum and could be restored by the addition of exogenous plasminogen. Localization of plasmin activity to the cell surface was critical for the degradation process as aprotinin, but not α2 antiplasmin, prevented collagen dissolution. During ECM degradation breast cancer cell lines expressed urokinase-type plasminogen activator (u-PA and uPA receptor, and MMPs-1, -3, -9,-13, and -14. The normal breast epithelial cell line expressed low levels of MMPs-1, and -3, uPA and uPA receptor. Inhibitors of both the PAS (aprotinin and PA inhibitor-1 and MMPs (CT1166 and tisue inhibitor of metalloproteinase blocked collagen degradation, demonstrating the requirement of both plasminogen activation and MMP activity for degradation. The activation of MMP-13 in human breast cancer cells was prevented by plasminogen activator inhibitor-1 but not by tissue inhibitor of metalloproteinase-1, suggesting

  9. Epidermal growth factor receptor activation by diesel particles is mediated by tyrosine phosphatase inhibition

    International Nuclear Information System (INIS)

    Exposure to particulate matter (PM) is associated with increased cardiopulmonary morbidity and mortality. Diesel exhaust particles (DEP) are a major component of ambient PM and may contribute to PM-induced pulmonary inflammation. Proinflammatory signaling is mediated by phosphorylation-dependent signaling pathways whose activation is opposed by the activity of protein tyrosine phosphatases (PTPases) which thereby function to maintain signaling quiescence. PTPases contain an invariant catalytic cysteine that is susceptible to electrophilic attack. DEP contain electrophilic oxy-organic compounds that may contribute to the oxidant effects of PM. Therefore, we hypothesized that exposure to DEP impairs PTPase activity allowing for unopposed basal kinase activity. Here we report that exposure to 30 μg/cm2 DEP for 4 h induces differential activation of signaling in primary cultures of human airway epithelial cells (HAEC), a primary target cell in PM inhalation. In-gel kinase activity assay of HAEC exposed to DEPs of low (L-DEP), intermediate (I-DEP) or high (H-DEP) organic content showed differential activation of intracellular kinases. Exposure to these DEP also induced varying levels of phosphorylation of the receptor tyrosine kinase EGFR in a manner that requires EGFR kinase activity but does not involve receptor dimerization. We demonstrate that treatment with DEP results in an impairment of total and EGFR-directed PTPase activity in HAEC with a potency that is independent of the organic content of these particles. These data show that DEP-induced EGFR phosphorylation in HAEC is the result of a loss of PTPase activities which normally function to dephosphorylate EGFR in opposition to baseline EGFR kinase activity

  10. Hibiscus sabdariffa extractivities on cadmium-mediated alterations of human U937 cell viability and activation

    Institute of Scientific and Technical Information of China (English)

    Tebekeme Okoko; Diepreye Ere

    2012-01-01

    Objective:To investigate the effect of the anthocyanin-rich extract of Hibiscus sabdariffa (H. sabdariffa) calyx on the viability of cadmium-treated U937 cells and cadmium-mediated activation of U937-derived macrophages. Methods:The macrophage cell line U937 was treated with cadmium (0.1μmol/L) and later incubated with the anthocyanin-rich extract and cell viability was assessed via trypan blue staining. In the other experiment, the U937 cells were transformed to the macrophage form by treatment with phorbol 12, myristate 13, and acetate and incubated with cadmium (10μmol/L). The anthocyanin-rich extract was added to the cells later and subsequently, the supernatant of each cell culture was analysed for the production of tumour necrosis factor-alpha (TNF-α), interleukin 1 (IL-1), interleukin 6 (IL-6), nitric oxide, and catalase activity as indices for the activation of macrophages. Results:It revealed that the anthocynanin-rich extract significantly (P <0.05) increased the viability of the cells which was suppressed by cadmium when compared to quercetin dihydrate. The extract also reduced the cadmium-mediated production of the markers of macrophage-activation when compared to quercetin dihydrate. In both experiments, the activity of the extract was concentration-dependent (P <0.05). Conclusion:The findings show that H. sabdariffa possesses significant immunoprotective effect. These corroborate the immense reported antioxidant and medicinal potential of the calyces of the plant which could be exploited for pharmacological and neutraceutical advantages.

  11. Calcium-mediated agonists activate an inwardly rectified K+ channel in colonic secretory cells.

    Science.gov (United States)

    Devor, D C; Frizzell, R A

    1993-11-01

    Single-channel recording techniques were used to identify and characterize the K+ channel activated by Ca(2+)-mediated secretory agonists in T84 cells. Carbachol (CCh; 100 microM) and taurodeoxycholate (TDC; 0.75 mM) stimulated oscillatory outward K+ currents. With K gluconate in bath and pipette, cell-attached single-channel K+ currents stimulated by CCh and ionomycin (2 microM) were inwardly rectified and reversed at 0 mV. The single-channel chord conductance was 32 pS at -90 mV and 14 pS at +90 mV. Similar properties were observed in excised inside-out patches in symmetric K+, permitting further characterization of channel properties. Partial substitution of bath or pipette K+ with Na+ gave a K(+)-to-Na+ selectivity ratio of 5.5:1. Channel activity increased with increasing bath Ca2+ concentration in the physiological range of 50-800 nM. Maximal channel activity occurred at intracellular pH 7.2 and decreased at more acidic or alkaline pH values. Extracellular charybdotoxin (CTX; 50 nM) blocked inward but not outward currents. Extracellular tetraethylammonium (TEA; 10 mM) reduced single-channel amplitude at all voltages. No apparent block of the channel was observed with extracellular Ba2+ (1 mM), apamin (1 microM), 4-aminopyridine (4-AP; 4 mM), quinine (500 microM), or glyburide (10 microM). Cytosolic quinine and 4-AP blocked both inward and outward currents, whereas Ba2+ blocked only outward currents. Apamin, CTX, TEA, and glyburide did not affect channel activity. The agonist activation and pharmacological profile of this inwardly rectified K+ channel indicate that it is responsible for the increase in basolateral K+ conductance stimulated by Ca(2+)-mediated agonists in T84 cells. PMID:7694492

  12. Human serum activates CIDEB-mediated lipid droplet enlargement in hepatoma cells

    International Nuclear Information System (INIS)

    Highlights: •Human serum induced differentiation of hepatoma cells increases cellular lipid droplet (LD) size. •The observed increase in LD size correlates with increased PGC-1α and CIDEB expression. •Induction of CIDEB expression correlates with rescue of VLDL secretion and loss of ADRP. •siRNA knockdown of CIDEB impairs the human serum mediated increase in LD size. •This system represents a cost-efficient model to study CIDEB’s role in lipid biology. -- Abstract: Human hepatocytes constitutively express the lipid droplet (LD) associated protein cell death-inducing DFFA-like effector B (CIDEB). CIDEB mediates LD fusion, as well as very-low-density lipoprotein (VLDL) maturation. However, there are limited cell culture models readily available to study CIDEB’s role in these biological processes, as hepatoma cell lines express negligible levels of CIDEB. Recent work has highlighted the ability of human serum to differentiate hepatoma cells. Herein, we demonstrate that culturing Huh7.5 cells in media supplemented with human serum activates CIDEB expression. This activation occurs through the induced expression of PGC-1α, a positive transcriptional regulator of CIDEB. Coherent anti-Stokes Raman scattering (CARS) microscopy revealed a correlation between CIDEB levels and LD size in human serum treated Huh7.5 cells. Human serum treatment also resulted in a rapid decrease in the levels of adipose differentiation-related protein (ADRP). Furthermore, individual overexpression of CIDEB was sufficient to down-regulate ADRP protein levels. siRNA knockdown of CIDEB revealed that the human serum mediated increase in LD size was CIDEB-dependent. Overall, our work highlights CIDEB’s role in LD fusion, and presents a new model system to study the PGC-1α/CIDEB pathway’s role in LD dynamics and the VLDL pathway

  13. Physical Activity and Cognitive Function in Older Adults: The Mediating Effect of Depressive Symptoms.

    Science.gov (United States)

    Vance, David E; Marson, Daniel C; Triebel, Kristen L; Ball, Karlene K; Wadley, Virginia G; Cody, Shameka L

    2016-01-01

    Depressive symptoms and social networks may influence the relationship between physical activity and cognition. Using structural equation modeling, depressive symptoms and social networks were examined as mediators between physical activity and cognition in community-dwelling older adults (N = 122), with a range of cognitive abilities (e.g., normal, mild cognitive impairment). The model included age, physical activity, sedentary behavior, sleeping, social networks, depressive symptoms, and cognitive function. A path was observed between physical activity, depressive symptoms, and cognition; specifically, those who were more physically active experienced less depression and better cognitive functioning. No relationship between social networks and cognition was found. This model fits the data well (goodness-of-fit index = .93, adjusted goodness-of-fit index = .90, root mean square error of approximation = .06). Results suggest that physical activity may mitigate depressive symptoms, with beneficial effects on cognitive functioning in both those with and without mild cognitive impairment. Suggestions for managing depression and improving cognitive functioning are provided. PMID:27224681

  14. CFTR mediates bicarbonate-dependent activation of miR-125b in preimplantation embryo development

    Institute of Scientific and Technical Information of China (English)

    Yong Chao Lu; Alvin Chun Hang Ma; Anskar Yu Hung Leung; He Feng Huang; Hsiao Chang Chan; Hui Chen; Kin Lam Fok; Lai Ling Tsang; Mei Kuen Yu; Xiao Hu Zhang; Jing Chen; Xiaohua Jiang; Yiu Wa Chung

    2012-01-01

    Although HCO3-is known to be required for early embryo development,its exact role remains elusive.Here we report that HCO3-acts as an environmental cue in regulating miR-125b expression through CFTR-mediated influx during preimplantation embryo development.The results show that the effect of HCO3-on preimplantation embryo development can be suppressed by interfering the function of a HCO3--conducting channel,CFTR,by a specific inhibitor or gene knockout.Removal of extracellular HCO3-or inhibition of CFTR reduces miR-125b expression in 2 cell-stage mouse embryos.Knockdown of miR-125b mimics the effect of HCO3-removal and CFTR inhibition,while injection of miR-125b precursor reverses it.Downregulation of miR-125b upregulates p53 cascade in both human and mouse embryos.The activation of miR-125b is shown to be mediated by sAC/PKA-dependent nuclear shuttling of NF-KB.These results have revealed a critical role of CFTR in signal transduction linking the environmental HCO3-to activation of miR-125b during preimplantation embryo development and indicated the importance of ion channels in regulation of miRNAs.

  15. Inflammasome activation of IL-1 family mediators in response to cutaneous photodamage.

    Science.gov (United States)

    Nasti, Tahseen H; Timares, Laura

    2012-01-01

    Although keratinocytes are relatively resistant to ultraviolet radiation (UVR) induced damage, repeated UVR exposure result in accumulated DNA mutations that can lead to epidermal malignancies. Keratinocytes play a central role in elaborating innate responses that lead to inflammation and influence the generation of adaptive immune responses in skin. Apart from the minor cellular constituents of the epidermis, specifically Langerhans cells and melanocytes, keratinocytes are the major source of cytokines. UVR exposure stimulates keratinocytes to secrete abundant pro-inflammatory IL-1-family proteins, IL-1α, IL-1β, IL-18, and IL-33. Normal skin contains only low levels of inactive precursor forms of IL-1β and IL-18, which require caspase 1-mediated proteolysis for their maturation and secretion. However, caspase-1 activation is not constitutive, but dependents on the UV-induced formation of an active inflammasome complex. IL-1 family cytokines can induce a secondary cascade of mediators and cytokines from keratinocytes and other cells resulting in wide range of innate processes including infiltration of inflammatory leukocytes, induction of immunosuppression, DNA repair or apoptosis. Thus, the ability of keratinocytes to produce a wide repertoire of proinflammatory cytokines can influence the immune response locally as well as systematically, and alter the host response to photodamaged cells. We will highlight differential roles played by each IL-1 family molecule generated by UV-damaged keratinocytes, and reveal their complementary influences in modulating acute inflammatory and immunological events that follow cutaneous UV exposure. PMID:22631445

  16. Structural Waters Define a Functional Channel Mediating Activation of the GPCR, rhodopsin

    Energy Technology Data Exchange (ETDEWEB)

    Angel, T.; Gupta, S; Jastrzebska, B; Palczewski, K; Chance, M

    2009-01-01

    Structural water molecules may act as prosthetic groups indispensable for proper protein function. In the case of allosteric activation of G protein-coupled receptors (GPCRs), water likely imparts structural plasticity required for agonist-induced signal transmission. Inspection of structures of GPCR superfamily members reveals the presence of conserved embedded water molecules likely important to GPCR function. Coupling radiolytic hydroxyl radical labeling with rapid H2O18 solvent mixing, we observed no exchange of these structural waters with bulk solvent in either ground state or for the Meta II or opsin states. However, the radiolysis approach permitted labeling of selected side chain residues within the transmembrane helices and revealed activation-induced changes in local structural constraints likely mediated by dynamics of both water and protein. These results suggest both a possible general mechanism for water-dependent communication in family A GPCRs based on structural conservation, and a strategy for probing membrane protein structure.

  17. AMP-activated protein kinase mediates mitochondrial fission in response to energy stress

    Science.gov (United States)

    Courchet, Julien; Lewis, Tommy L.; Losón, Oliver C.; Hellberg, Kristina; Young, Nathan P.; Chen, Hsiuchen; Polleux, Franck; Chan, David C.; Shaw, Reuben J.

    2016-01-01

    Mitochondria undergo fragmentation in response to electron transport chain (ETC) poisons and mitochondrial DNA–linked disease mutations, yet how these stimuli mechanistically connect to the mitochondrial fission and fusion machinery is poorly understood. We found that the energy-sensing adenosine monophosphate (AMP)–activated protein kinase (AMPK) is genetically required for cells to undergo rapid mitochondrial fragmentation after treatment with ETC inhibitors. Moreover, direct pharmacological activation of AMPK was sufficient to rapidly promote mitochondrial fragmentation even in the absence of mitochondrial stress. A screen for substrates of AMPK identified mitochondrial fission factor (MFF), a mitochondrial outer-membrane receptor for DRP1, the cytoplasmic guanosine triphosphatase that catalyzes mitochondrial fission. Nonphosphorylatable and phosphomimetic alleles of the AMPK sites in MFF revealed that it is a key effector of AMPK-mediated mitochondrial fission. PMID:26816379

  18. Diagnostic performance of CT versus MR in detecting aldosterone-producing adenoma in primary hyperaldosteronism (Conn's syndrome)

    International Nuclear Information System (INIS)

    The aim of the present study is to compare the diagnostic performance of CT and MR imaging in detecting aldosterone-producing adenoma and to compare the interobserver variability in the detection of an aldosterone-producing adenoma on CT and MR. A retrospective study of 34 patients with primary hyperaldosteronism was performed. A total of 17 cases of aldosterone-producing adenoma and 17 cases of bilateral adrenal hyperplasia were included. The final diagnosis of an adenoma was made by surgery with histological confirmation, whereas that of bilateral adrenal hyperplasia was made on adrenal venous sampling or a good biochemical and clinical response following medical treatment alone and in the absence of a unilateral radiological abnormality. The CT (n=30) and MR (n=24) scans were reviewed independently by two radiologists experienced in adrenal imaging, who were unaware of the cause of the primary hyperaldosteronism. The diagnostic performances of both observers in detecting an aldosterone-producing adenoma on CT and MR imaging were compared. The 16 adenomatous nodules that were detected on imaging ranged from 1 to 4.75 cm in diameter. The calculated sensitivity and specificity for detecting aldosterone-producing adenoma were 87 and 93% for one observer and 85 and 82% for the other observer on CT, and 83 and 83% for one observer and 92 and 92% for the other observer on MR, respectively. Receptor operating characteristics curve analysis showed similar performances of both observers in detecting an aldosterone-producing adenoma on CT and MR imaging. There was good interobserver agreement on CT (k=0.71) and on MR (k=0.67). We have demonstrated comparable diagnostic performance and good interobserver agreement on CT and MR imaging for the detection of aldosterone-producing adenoma. (orig.)

  19. 1,25 Dihydroxyvitamin D3 Inhibits TGFβ1-Mediated Primary Human Cardiac Myofibroblast Activation.

    Directory of Open Access Journals (Sweden)

    Anna Meredith

    Full Text Available Epidemiological and interventional studies have suggested a protective role for vitamin D in cardiovascular disease, and basic research has implicated vitamin D as a potential inhibitor of fibrosis in a number of organ systems; yet little is known regarding direct effects of vitamin D on human cardiac cells. Given the critical role of fibrotic responses in end stage cardiac disease, we examined the effect of active vitamin D treatment on fibrotic responses in primary human adult ventricular cardiac fibroblasts (HCF-av, and investigated the relationship between circulating vitamin D (25(OHD3 and cardiac fibrosis in human myocardial samples.Interstitial cardiac fibrosis in end stage HF was evaluated by image analysis of picrosirius red stained myocardial sections. Serum 25(OHD3 levels were assayed using mass spectrometry. Commercially available HCF-av were treated with transforming growth factor (TGFβ1 to induce activation, in the presence or absence of active vitamin D (1,25(OH2D3. Functional responses of fibroblasts were analyzed by in vitro collagen gel contraction assay. 1,25(OH2D3 treatment significantly inhibited TGFβ1-mediated cell contraction, and confocal imaging demonstrated reduced stress fiber formation in the presence of 1,25(OH2D3. Treatment with 1,25(OH2D3 reduced alpha-smooth muscle actin expression to control levels and inhibited SMAD2 phosphorylation.Our results demonstrate that active vitamin D can prevent TGFβ1-mediated biochemical and functional pro-fibrotic changes in human primary cardiac fibroblasts. An inverse relationship between vitamin D status and cardiac fibrosis in end stage heart failure was observed. Collectively, our data support an inhibitory role for vitamin D in cardiac fibrosis.

  20. The HEART mobile phone trial: The partial mediating effects of self-efficacy on physical activity among cardiac patients

    Directory of Open Access Journals (Sweden)

    Ralph eMaddison

    2014-05-01

    Full Text Available Background: The ubiquitous use of mobile phones provides an ideal opportunity to deliver interventions to increase physical activity levels. Understanding potential mediators of such interventions is needed to increase their effectiveness. A recent randomized controlled trial of a mobile phone and Internet (mHealth intervention was conducted in New Zealand to determine the effectiveness on exercise capacity and physical activity levels in addition to current cardiac rehabilitation (CR services for people (n=171 with ischaemic heart disease (IHD. Significant intervention effect was observed for self-reported leisure time physical activity and walking, but not peak oxygen uptake (PVO2 at 24 weeks. There was also significant improvement in self-efficacy.Objective: To evaluate the mediating effect of self-efficacy on physical activity levels in an mHealth delivered exercise CR programme. Methods: Treatment evaluations were performed on the principle of intention to treat (ITT. Adjusted regression analyses were conducted to evaluate the main treatment effect on leisure time physical activity and walking at 24 weeks, with and without change in self-efficacy as the mediator of interest. Results: Change in self-efficacy at 24 weeks significantly mediated the treatment effect on leisure time physical activity by 13%, but only partially mediated the effect on walking by 4% at 24 weeks. Conclusion: An mHealth intervention involving text messaging and Internet support had a positive treatment effect on leisure time physical activity and walking at 24 weeks, and this effect was likely mediated through changes in self-efficacy. Future trials should examine other potential mediators related to this type of intervention.

  1. Shape-dependent bactericidal activity of copper oxide nanoparticle mediated by DNA and membrane damage

    International Nuclear Information System (INIS)

    Highlights: • Spherical and sheet shaped copper oxide nanoparticles were synthesized. • Physical characterizations of these nanoparticles were done by TEM, DLS, XRD, FTIR. • They showed shape dependent antibacterial activity on different bacterial strain. • They induced both membrane damage and ROS mediated DNA damage in bacteria. - Abstract: In this work, we synthesized spherical and sheet shaped copper oxide nanoparticles and their physical characterizations were done by the X-ray diffraction, fourier transform infrared spectroscopy, transmission electron microscopy and dynamic light scattering. The antibacterial activity of these nanoparticles was determined on both gram positive and gram negative bacterial. Spherical shaped copper oxide nanoparticles showed more antibacterial property on gram positive bacteria where as sheet shaped copper oxide nanoparticles are more active on gram negative bacteria. We also demonstrated that copper oxide nanoparticles produced reactive oxygen species in both gram negative and gram positive bacteria. Furthermore, they induced membrane damage as determined by atomic force microscopy and scanning electron microscopy. Thus production of and membrane damage are major mechanisms of the bactericidal activity of these copper oxide nanoparticles. Finally it was concluded that antibacterial activity of nanoparticles depend on physicochemical properties of copper oxide nanoparticles and bacterial strain

  2. Seizure-mediated neuronal activation induces DREAM gene expression in the mouse brain.

    Science.gov (United States)

    Matsu-ura, Toru; Konishi, Yoshiyuki; Aoki, Tsutomu; Naranjo, Jose R; Mikoshiba, Katsuhiko; Tamura, Taka-aki

    2002-12-30

    Various transcriptional activators are induced in neurons concomitantly with long-lasting neural activity, whereas only a few transcription factors are known to act as neural activity-inducible transcription repressors. In this study, mRNA of DREAM (DRE-antagonizing modulator), a Ca(2+)-modulated transcriptional repressor, was demonstrated to accumulate in the mouse brain after pentylenetetrazol (PTZ)-induced seizures. Accumulation in the mouse hippocampus reached maximal level in the late phase (at 7-8 h) after PTZ injection. Kainic acid induced the same response. Interestingly, the late induction of DREAM expression required new protein synthesis and was blocked by MK801 suggesting that Ca(2+)-influx via NMDA receptors is necessary for the PTZ-mediated DREAM expression. In situ hybridization revealed that PTZ-induced DREAM mRNA accumulation was observed particularly in the dentate gyrus, cerebral cortex, and piriform cortex. The results of the present study demonstrate that DREAM is a neural activity-stimulated late gene and suggest its involvement in adaptation to long-lasting neuronal activity. PMID:12531529

  3. Complex molecular mechanisms cooperate to mediate histone deacetylase inhibitors anti-tumour activity in neuroblastoma cells

    Directory of Open Access Journals (Sweden)

    Nardou Katya

    2008-06-01

    Full Text Available Abstract Background Histone deacetylase inhibitors (HDACi are a new class of promising anti-tumour agent inhibiting cell proliferation and survival in tumour cells with very low toxicity toward normal cells. Neuroblastoma (NB is the second most common solid tumour in children still associated with poor outcome in higher stages and, thus NB strongly requires novel treatment modalities. Results We show here that the HDACi Sodium Butyrate (NaB, suberoylanilide hydroxamic acid (SAHA and Trichostatin A (TSA strongly reduce NB cells viability. The anti-tumour activity of these HDACi involved the induction of cell cycle arrest in the G2/M phase, followed by the activation of the intrinsic apoptotic pathway, via the activation of the caspases cascade. Moreover, HDACi mediated the activation of the pro-apoptotic proteins Bid and BimEL and the inactivation of the anti-apoptotic proteins XIAP, Bcl-xL, RIP and survivin, that further enhanced the apoptotic signal. Interestingly, the activity of these apoptosis regulators was modulated by several different mechanisms, either by caspases dependent proteolytic cleavage or by degradation via the proteasome pathway. In addition, HDACi strongly impaired the hypoxia-induced secretion of VEGF by NB cells. Conclusion HDACi are therefore interesting new anti-tumour agents for targeting highly malignant tumours such as NB, as these agents display a strong toxicity toward aggressive NB cells and they may possibly reduce angiogenesis by decreasing VEGF production by NB cells.

  4. Home environment as a predictor of child's language: A mediating role of family literacy activities and symbolic play

    Directory of Open Access Journals (Sweden)

    Urška Fekonja-Peklaj

    2015-06-01

    Full Text Available In our study, we explored the ways in which SES-related factors of family environment affect child's language across toddlerhood and early childhood. We proposed a mediational path model in which we presumed that family literacy activities and parental encouragement of symbolic play acted as mediating variables, mediating the effect of parental education, family possessions and parent-to-child speech on child's language. The sample included 99 families with children, aged from 1 to 6 years. The data were collected in the family home, mostly via direct observation and by using a semi-structured interview with parents. The findings suggest that high-SES parents and parents who used a more complex and supportive speech, more frequently involved their children in different literacy activities. The effect of the parent-to-child speech on child's language proved to be mediated by parental use of mental transformations during symbolic play with a child.

  5. Energy National Mediator activity report 2009; Rapport d'activite du Mediateur National de l'Energie 2009

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    After some data illustrating the activity of the Energy National Mediator in 2009, and an interview of a representative of this institution who comments its practice, this report proposes the opinions of the different involved actors (communities, consumer associations, providers, and so on) about the mediator. It puts the adopted strategy in perspective from the past year to the coming one. It describes the missions: information, advice, protection. It reports actions, recommendations and facts for 2009 in terms of consumer information, group mediation, poverty management, samples of analysed disputes. It presents the social organisation and gives a financial assessment of the institution

  6. Cytochrome P450-mediated activation of the fragrance compound geraniol forms potent contact allergens

    International Nuclear Information System (INIS)

    Contact sensitization is caused by low molecular weight compounds which penetrate the skin and bind to protein. In many cases, these compounds are activated to reactive species, either by autoxidation on exposure to air or by metabolic activation in the skin. Geraniol, a widely used fragrance chemical, is considered to be a weak allergen, although its chemical structure does not indicate it to be a contact sensitizer. We have shown that geraniol autoxidizes and forms allergenic oxidation products. In the literature, it is suggested but not shown that geraniol could be metabolically activated to geranial. Previously, a skin-like CYP cocktail consisting of cutaneous CYP isoenzymes, was developed as a model system to study cutaneous metabolism. In the present study, we used this system to investigate CYP-mediated activation of geraniol. In incubations with the skin-like CYP cocktail, geranial, neral, 2,3-epoxygeraniol, 6,7-epoxygeraniol and 6,7-epoxygeranial were identified. Geranial was the main metabolite formed followed by 6,7-epoxygeraniol. The allergenic activities of the identified metabolites were determined in the murine local lymph node assay (LLNA). Geranial, neral and 6,7-epoxygeraniol were shown to be moderate sensitizers, and 6,7-epoxygeranial a strong sensitizer. Of the isoenzymes studied, CYP2B6, CYP1A1 and CYP3A5 showed high activities. It is likely that CYP1A1 and CYP3A5 are mainly responsible for the metabolic activation of geraniol in the skin, as they are expressed constitutively at significantly higher levels than CYP2B6. Thus, geraniol is activated through both autoxidation and metabolism. The allergens geranial and neral are formed via both oxidation mechanisms, thereby playing a large role in the sensitization to geraniol

  7. Dynamic Regulation of Activated Leukocyte Cell Adhesion Molecule–mediated Homotypic Cell Adhesion through the Actin CytoskeletonV⃞

    OpenAIRE

    Nelissen, Judith M. D. T.; Peters, Inge M.; de Grooth, Bart G.; Van Kooyk, Yvette; Figdor, Carl G.

    2000-01-01

    Restricted expression of activated leukocyte cell adhesion molecule (ALCAM) by hematopoietic cells suggests an important role in the immune system and hematopoiesis. To get insight into the mechanisms that control ALCAM-mediated adhesion we have investigated homotypic ALCAM–ALCAM interactions. Here, we demonstrate that the cytoskeleton regulates ALCAM-mediated cell adhesion because inhibition of actin polymerization by cytochalasin D (CytD) strongly induces homotypic ALCAM–ALCAM interactions....

  8. Cholinergic-mediated IP3-receptor activation induces long-lasting synaptic enhancement in CA1 pyramidal neurons

    OpenAIRE

    Fernández de Sevilla, D.; Núñez Molina, Ángel; Borde, M.; Malinow, R.; Buño, Washinton

    2008-01-01

    Cholinergic-glutamatergic interactions influence forms of synaptic plasticity that are thought to mediate memory and learning. We tested in vitro the induction of long-lasting synaptic enhancement at Schaffer collaterals by acetylcholine (ACh) at the apical dendrite of CA1 pyramidal neurons and in vivo by stimulation of cholinergic afferents. In vitro ACh induced a Ca2+ wave and synaptic enhancement mediated by insertion of AMPA receptors in spines. Activation of muscarinic ACh receptors (mAC...

  9. Activation of AML1-mediated transcription by MOZ and inhibition by the MOZ–CBP fusion protein

    OpenAIRE

    Kitabayashi, Issay; Aikawa, Yukiko; Nguyen, Lan Anh; Yokoyama, Akihiko; Ohki, Misao

    2001-01-01

    The AML1–CBFβ transcription factor complex is the most frequent target of specific chromosome translocations in human leukemia. The MOZ gene, which encodes a histone acetyltransferase (HAT), is also involved in some leukemia-associated translocations. We report here that MOZ is part of the AML1 complex and strongly stimulates AML1-mediated transcription. The stimulation of AML1-mediated transcription is independent of the inherent HAT activity of MOZ. Rather, a potent transactivation domain w...

  10. Hydrogen adsorption-mediated synthesis of concave Pt nanocubes and their enhanced electrocatalytic activity

    Science.gov (United States)

    Lu, Bang-An; Du, Jia-Huan; Sheng, Tian; Tian, Na; Xiao, Jing; Liu, Li; Xu, Bin-Bin; Zhou, Zhi-You; Sun, Shi-Gang

    2016-06-01

    Concave nanocubes are enclosed by high-index facets and have negative curvature; they are expected to have enhanced reactivity, as compared to nanocubes with flat surfaces. Herein, we propose and demonstrate a new strategy for the synthesis of concave Pt nanocubes with {hk0} high-index facets, by using a hydrogen adsorption-mediated electrochemical square-wave potential method. It was found that Pt atoms prefer to deposit on edge sites rather than terrace sites on Pt surfaces with intensive hydrogen adsorption, resulting in the formation of concave structures. The as-prepared concave Pt nanocubes exhibit enhanced catalytic activity and stability towards oxidation of ethanol and formic acid in acidic solutions, compared to commercial Pt/C catalysts.Concave nanocubes are enclosed by high-index facets and have negative curvature; they are expected to have enhanced reactivity, as compared to nanocubes with flat surfaces. Herein, we propose and demonstrate a new strategy for the synthesis of concave Pt nanocubes with {hk0} high-index facets, by using a hydrogen adsorption-mediated electrochemical square-wave potential method. It was found that Pt atoms prefer to deposit on edge sites rather than terrace sites on Pt surfaces with intensive hydrogen adsorption, resulting in the formation of concave structures. The as-prepared concave Pt nanocubes exhibit enhanced catalytic activity and stability towards oxidation of ethanol and formic acid in acidic solutions, compared to commercial Pt/C catalysts. Electronic supplementary information (ESI) available: Details of DFT calculation, SEM images of concave Pt nanocubes, mass activity and stability characterization of the catalysts. See DOI: 10.1039/c6nr02349e

  11. Bradykinin-mediated angioedema.

    Science.gov (United States)

    Obtułowicz, Krystyna

    2016-02-01

    Angioedema and urticaria often constitute a challenge in daily clinical practice. They may either co- -occur or present as independent conditions. They are characterized by a complex pathomechanism, and their symptoms may be triggered by diverse factors. These differences are crucial for developing a successful treatment regimen. Both conditions may have an allergic origin (immunoglobulin [Ig] E and non-IgE-related), usually induced by histamine, or a nonallergic one, such as bradykinin-mediated angioedema in patients with C1 inhibitor (C1-INH) deficiency or angioedema induced by certain drugs (eg, angiotensin-converting enzyme inhibitors). Currently, we distinguish 5 types of nonallergic angioedema: hereditary angioedema (HAE) due to C1-INH deficiency, acquired angioedema (AAE), and angioedema induced by the renin-angiotensin-aldosterone system, all of which are mediated by bradykinin, as well as pseudoallergic angioedema and idiopathic angioedema. Bradykinin-mediated angioedema (eg, laryngeal angioedema) may be life-threatening because of resistance to corticosteroids and antihistamine drugs. C1-INH concentrates are the drugs of choice in the treatment of HAE and AAE. In recent years, some new drugs have been introduced in the treatment of bradykinin-mediated angioedema, such as bradykinin B2-receptor antagonist, icatibant, and kallikrein inhibitor, ecallantide, which allow to improve treatment outcomes. PMID:26842379

  12. Integrating Social Activity Theory and Critical Discourse Analysis: A Multilayered Methodological Model for Examining Knowledge Mediation in Mentoring

    Science.gov (United States)

    Becher, Ayelet; Orland-Barak, Lily

    2016-01-01

    This study suggests an integrative qualitative methodological framework for capturing complexity in mentoring activity. Specifically, the model examines how historical developments of a discipline direct mentors' mediation of professional knowledge through the language that they use. The model integrates social activity theory and a framework of…

  13. Avoidance of activity and disability in patients with osteoarthritis of the knee: the mediating role of muscle strength.

    NARCIS (Netherlands)

    Steultjens, M.P.M.; Dekker, J.; Bijlsma, J.W.J.

    2002-01-01

    OBJECTIVE: Avoidance of activity is hypothesized to lead to muscle weakness and consequently, to physical disability. This study was undertaken to validate the avoidance model by providing evidence for the mediating role of muscle weakness in the relationship between avoidance of activity and physic

  14. A CaMK cascade activates CRE-mediated transcription in neurons of Caenorhabditis elegans

    Science.gov (United States)

    Kimura, Yoshishige; Corcoran, Ethan E.; Eto, Koh; Gengyo-Ando, Keiko; Muramatsu, Masa-aki; Kobayashi, Ryoji; Freedman, Jonathan H.; Mitani, Shohei; Hagiwara, Masatoshi; Means, Anthony R.; Tokumitsu, Hiroshi

    2002-01-01

    Calcium (Ca2+) signals regulate a diverse set of cellular responses, from proliferation to muscular contraction and neuro-endocrine secretion. The ubiquitous Ca2+ sensor, calmodulin (CaM), translates changes in local intracellular Ca2+ concentrations into changes in enzyme activities. Among its targets, the Ca2+/CaM-dependent protein kinases I and IV (CaMKs) are capable of transducing intraneuronal signals, and these kinases are implicated in neuronal gene regulation that mediates synaptic plasticity in mammals. Recently, the cyclic AMP response element binding protein (CREB) has been proposed as a target for a CaMK cascade involving not only CaMKI or CaMKIV, but also an upstream kinase kinase that is also CaM regulated (CaMKK). Here, we report that all components of this pathway are coexpressed in head neurons of Caenorhabditis elegans. Utilizing a transgenic approach to visualize CREB-dependent transcription in vivo, we show that this CaMK cascade regulates CRE-mediated transcription in a subset of head neurons in living nematodes. PMID:12231504

  15. PLCγ-activated signalling is essential for TrkB mediated sensory neuron structural plasticity

    Directory of Open Access Journals (Sweden)

    Rocha-Sanchez Sonia M

    2010-10-01

    Full Text Available Abstract Background The vestibular system provides the primary input of our sense of balance and spatial orientation. Dysfunction of the vestibular system can severely affect a person's quality of life. Therefore, understanding the molecular basis of vestibular neuron survival, maintenance, and innervation of the target sensory epithelia is fundamental. Results Here we report that a point mutation at the phospholipase Cγ (PLCγ docking site in the mouse neurotrophin tyrosine kinase receptor TrkB (Ntrk2 specifically impairs fiber guidance inside the vestibular sensory epithelia, but has limited effects on the survival of vestibular sensory neurons and growth of afferent processes toward the sensory epithelia. We also show that expression of the TRPC3 cation calcium channel, whose activity is known to be required for nerve-growth cone guidance induced by brain-derived neurotrophic factor (BDNF, is altered in these animals. In addition, we find that absence of the PLCγ mediated TrkB signalling interferes with the transformation of bouton type afferent terminals of vestibular dendrites into calyces (the largest synaptic contact of dendrites known in the mammalian nervous system on type I vestibular hair cells; the latter are normally distributed in these mutants as revealed by an unaltered expression pattern of the potassium channel KCNQ4 in these cells. Conclusions These results demonstrate a crucial involvement of the TrkB/PLCγ-mediated intracellular signalling in structural aspects of sensory neuron plasticity.

  16. Activation of the endothelin system mediates pathological angiogenesis during ischemic retinopathy.

    Science.gov (United States)

    Patel, Chintan; Narayanan, S Priya; Zhang, Wenbo; Xu, Zhimin; Sukumari-Ramesh, Sangeetha; Dhandapani, Krishnan M; Caldwell, R William; Caldwell, Ruth B

    2014-11-01

    Retinopathy of prematurity adversely affects premature infants because of oxygen-induced damage of the immature retinal vasculature, resulting in pathological neovascularization (NV). Our pilot studies using the mouse model of oxygen-induced retinopathy (OIR) showed marked increases in angiogenic mediators, including endothelins and endothelin receptor (EDNR) A. We hypothesized that activation of the endothelin system via EDNRA plays a causal role in pathological angiogenesis and up-regulation of angiogenic mediators, including vascular endothelial growth factor A (VEGFA) in OIR. Mice were exposed to 75% oxygen from post-natal day P7 to P12, treated with either vehicle or EDNRA antagonist BQ-123 or EDNRB antagonist BQ-788 on P12, and kept at room air from P12 to P17 (ischemic phase). RT-PCR analysis revealed increased levels of EDN2 and EDNRA mRNA, and Western blot analysis revealed increased EDN2 expression during the ischemic phase. EDNRA inhibition significantly increased vessel sprouting, resulting in enhanced physiological angiogenesis and decreased pathological NV, whereas EDNRB inhibition modestly improved vascular repair. OIR triggered significant increases in VEGFA protein and mRNA for delta-like ligand 4, apelin, angiopoietin-2, and monocyte chemoattractant protein-1. BQ-123 treatment significantly reduced these alterations. EDN2 expression was localized to retinal glia and pathological NV tufts of the OIR retinas. EDN2 also induced VEGFA protein expression in cultured astrocytes. In conclusion, inhibition of the EDNRA during OIR suppresses pathological NV and promotes physiological angiogenesis. PMID:25203536

  17. Activation of archaeal transcription mediated by recruitment of transcription factor B.

    Science.gov (United States)

    Ochs, Simon M; Thumann, Sybille; Richau, Renate; Weirauch, Matt T; Lowe, Todd M; Thomm, Michael; Hausner, Winfried

    2012-05-25

    Archaeal promoters consist of a TATA box and a purine-rich adjacent upstream sequence (transcription factor B (TFB)-responsive element (BRE)), which are bound by the transcription factors TATA box-binding protein (TBP) and TFB. Currently, only a few activators of archaeal transcription have been experimentally characterized. The best studied activator, Ptr2, mediates activation by recruitment of TBP. Here, we present a detailed biochemical analysis of an archaeal transcriptional activator, PF1088, which was identified in Pyrococcus furiosus by a bioinformatic approach. Operon predictions suggested that an upstream gene, pf1089, is polycistronically transcribed with pf1088. We demonstrate that PF1088 stimulates in vitro transcription by up to 7-fold when the pf1089 promoter is used as a template. By DNase I and hydroxyl radical footprinting experiments, we show that the binding site of PF1088 is located directly upstream of the BRE of pf1089. Mutational analysis indicated that activation requires the presence of the binding site for PF1088. Furthermore, we show that activation of transcription by PF1088 is dependent upon the presence of an imperfect BRE and is abolished when the pf1089 BRE is replaced with a BRE from a strong archaeal promoter. Gel shift experiments showed that TFB recruitment to the pf1089 operon is stimulated by PF1088, and TFB seems to stabilize PF1088 operator binding even in the absence of TBP. Taken together, these results represent the first biochemical evidence for a transcriptional activator working as a TFB recruitment factor in Archaea, for which the designation TFB-RF1 is suggested. PMID:22496454

  18. Adenovirus-mediated wild-type PTEN promoting glioma stem/progenitor cells autophagy activity

    Directory of Open Access Journals (Sweden)

    ZHAO Yao-dong

    2013-05-01

    Full Text Available Background PTEN is an anti-oncogene frequently inactivating in glioma. The previous study found that PTEN was closely related to cellular autophagy activity. The purpose of this paper is to study whether the inactivation of PTEN in glioma stem/progenitor cells (GSPCs is correlative with the low autophagic activity in GSPCs. Methods Wild-type PTEN genes were transferred into GSPCs mediated by adenovirus. The autophagic activity in GSPCs before or after the introduction of wild-type PTEN was detected by immunocytochemistry, electron microscopy, and Western blotting assay. Results After transfection of wild-type PTEN, a large number of microtuble-associated protein 1 light chain 3 (MAP1LC3-positive granules could be found in the cytoplasm of GSPCs under a confocal microscopy, and these granules were demonstrated to be autophagosomes under an electron microscope. Moreover, the expression of autophagy-related gene Beclin-1 significantly increased after the transfection of wild-type PTEN gene. Conclusion The inactivation of PTEN in GSPCs is one reason of the low autophagic activity of GSPCs.

  19. Intein-mediated Rapid Purification of Recombinant Human Pituitary Adenylate Cyclase Activating Polypeptide

    Institute of Scientific and Technical Information of China (English)

    Rong-jie YU; An HONG; Yun DAI; Yuan GAO

    2004-01-01

    In order to obtain the recombinant human PACAP efficiently by intein-mediated single column purification, a gene encoding human PACAP was synthesized and cloned into Escherichia coli expression vector pKYB. The recombinant vector pKY-PAC was transferred into E. coli ER2566 cells and the target protein was over-expressed as a fusion to the N-terminus of a self-cleavable affinity tag. After the PACAPintein-CBD fusion protein was purified by chitin-affinity chromatography, the self-cleavage activity of the intein was induced by DTT and the rhPACAP was released from the chitin-bound intein tag. The activity of the rhPACAP to stimulate cyclic AMP accumulation was detected using the human pancreas carcinoma cells SW1990. Twenty-two milligrams of rhPACAP with the purity over 98% was obtained by single column purification from 1 liter of induced culture. The preliminary biological assay indicated that the rhPACAP, which has an extra Met at its N-terminus compared with the native human PACAP, had the similar activity of stimulating cAMP accumulation with the standard PACAP38 in the SW1990 cells. A new efficient production procedure of the active recombinant human PACAP was established.

  20. Platinum multicubes prepared by ni(2+) -mediated shape evolution exhibit high electrocatalytic activity for oxygen reduction.

    Science.gov (United States)

    Ma, Liang; Wang, Chengming; Xia, Bao Yu; Mao, Keke; He, Jiawei; Wu, Xiaojun; Xiong, Yujie; Lou, Xiong Wen David

    2015-05-01

    Pt(100) facets are generally considered less active for the oxygen reduction reaction (ORR). Reported herein is a unique Pt-branched structure, a multicube, whose surface is mostly enclosed by {100} facets but contains high-index facets at the small junction area between the adjacent cubic components. The synthesis is accomplished by a Ni(2+) -mediated facet evolution from high-index {311} to {100} facets on the frameworks of multipods. Despite the high {100} facet coverage, the Pt multicubes exhibit impressive ORR activity in terms of half-wave potential and current density nearly to the level of the most active Pt-based catalysts, while the durability of catalysts is well retained. The facet evolution creates a set of samples with tunable ratios of high-index to low-index facets. The results reveal that the excellent ORR performance of Pt multicubes is a combined result of active sites by high-index facets and low resistance by flat surface. It is anticipated that this work will offer a new approach to facet-controlled synthesis and ORR catalysts design. PMID:25756931

  1. AMPK activators suppress cervical cancer cell growth through inhibition of DVL3 mediated Wnt/β-catenin signaling activity.

    Directory of Open Access Journals (Sweden)

    H T Kwan

    Full Text Available Recent evidence has suggested that AMPK activators may be applied as therapeutic drugs in suppressing cancer cell growth. However, the molecular mechanism of their suppressive function in cancer cells is still unclear. Here we show that AMPK activators impair cervical cancer cell growth through the reduction of DVL3, a positive regulator in Wnt/β-catenin signaling and an oncogenic player in cervical cancer tumorigenesis. By western blot and immunohistochemical analyses, we demonstrated that DVL3 was frequently upregulated and significantly associated with elevated β-catenin (P = 0.009 and CyclinD1 (P = 0.009 expressions in cervical cancer. Enforced expression of DVL3 elevated β-catenin and augmented cervical cancer cell growth, verifying that DVL3-mediated Wnt/β-catenin activation is involved in cervical cancer oncogenesis. On the other aspect, we noted that the cervical cancer cell growth was remarkably suppressed by AMPK activators and such cell growth inhibition was in concomitant with the reduction of DVL3 protein level in dose- and time-dependent manners. Besides, impaired mTOR signaling activity also reduced DVL3 expression. In contrast, co-treatment with Compound C (AMPK inhibitor could significantly abrogate metformin induced DVL3 reduction. In addition, co-treatment with AM114 or MG132 (proteosomal inhibitors could partially restore DVL3 expression under the treatment of metformin. Further in vivo ubiquitination assay revealed that metformin could reduce DVL3 by ubiquitin/proteasomal degradation. To our knowledge, this is the first report showing the probable molecular mechanisms of that the AMPK activators suppress cervical cancer cell growth by impairing DVL3 protein synthesis via AMPK/mTOR signaling and/or partially promoting the proteasomal degradation of DVL3.

  2. Adrenalectomy mediated alterations in adrenergic activation of adenylate cyclase in rat liver

    International Nuclear Information System (INIS)

    Adrenalectomy caused a large increase in the number of β-adrenergic binding sites on liver plasma membranes as measured by 125I-iodocyanopindolol (22 and 102 fmol/mg protein for control and adrenalectomized (ADX) rats). Concomitantly an increase in the number of binding sites for 3H-yohimbine was also observed (104 and 175 fmol/mg protein for control and adx membranes). Epinephrine-stimulated increase in cyclic AMP accumulation in isolated hepatocytes were greater in cells from ADX rats. This increase in β-adrenergic mediated action was much less than what may be expected as a result of the increase in the β-adrenergic binding in ADX membranes. In addition phenoxybenzamine (10 μM) further augmented this action of epinephrine in both control and ADX cells. To test the hypothesis that the increase in the number of the inhibitory α2-adrenergic receptors in adrenalectomy is responsible for the muted β-adrenergic response, the authors injected rats with pertussis toxin (PT). This treatment may cause the in vivo ribosylation of the inhibitory binding protein (Ni). Adenylate cyclase (AC) activity in liver plasma membranes prepared from treated and untreated animals was measured. In contrast with control rats, treatment of ADX rats with PT resulted in a significant increase in the basal activity of AC (5.5 and 7.7 pmol/mg protein/min for untreated and treated rats respectively). Isoproterenol (10 μM), caused AC activity to increase to 6.5 and 8.4 pmol/mg protein/min for membranes obtained from ADX untreated and ADX treated rats respectively. The α-adrenergic antagonists had no significant effect on the β-adrenergic-mediated activation of AC in liver plasma membranes from PT treated control and ADX rats. The authors conclude that the β-adrenergic activation of AC is attenuated by Ni protein both directly and as a result of activation of α-adrenergic receptors

  3. Activation of Protease-Activated Receptor 2-Mediated Signaling by Mast Cell Tryptase Modulates Cytokine Production in Primary Cultured Astrocytes

    Directory of Open Access Journals (Sweden)

    Xiaoning Zeng

    2013-01-01

    Full Text Available Protease-activated receptor 2 (PAR-2, which is abundantly expressed in astrocytes, is known to play major roles in brain inflammation. However, the influence of the natural agonist of PAR-2, tryptase, on proinflammatory mediator releasedfrom astrocytes remains uninvestigated. In the present study, we found that tryptase at lower concentrations modestly reduced intracellular ROS production but significantly increased IL-6 and TNF-α secretion at higher concentrations without affecting astrocytic viability and proliferation. The actions of tryptase were alleviated by specific PAR-2 antagonist FSLLRY-NH2 (FS, indicating that the actions of tryptase were via PAR-2. PI3K/AKT inhibitor LY294002 reversed the effect of tryptase on IL-6 production, whereas inhibitors specific for p38, JNK, and ERK1/2 abolished the effect of tryptase on TNF-α production, suggesting that different signaling pathways are involved. Moreover, tryptase-induced activation of MAPKs and AKT was eliminated by FS, implicating that PAR-2 is responsible for transmitting tryptase biosignals to MAPKs and AKT. Tryptase provoked also expression of TGF-β and CNTF in astrocytes. The present findings suggest for the first time that tryptase can regulate the release of cytokines from astrocytes via PAR-2-MAPKs or PAR-2-PI3K/AKT signaling pathways, which reveals PAR-2 as a new target actively participating in the regulation of astrocytic functions.

  4. Interferon-mediated antiviral activities of Angelica tenuissima Nakai and its active components.

    Science.gov (United States)

    Weeratunga, Prasanna; Uddin, Md Bashir; Kim, Myun Soo; Lee, Byeong-Hoon; Kim, Tae-Hwan; Yoon, Ji-Eun; Ma, Jin Yeul; Kim, Hongik; Lee, Jong-Soo

    2016-01-01

    Angelica tenuissima Nakai is a widely used commodity in traditional medicine. Nevertheless, no study has been conducted on the antiviral and immune-modulatory properties of an aqueous extract of Angelica tenuissima Nakai. In the present study, we evaluated the antiviral activities and the mechanism of action of an aqueous extract of Angelica tenuissima Nakai both in vitro and in vivo. In vitro, an effective dose of Angelica tenuissima Nakai markedly inhibited the replication of Influenza A virus (PR8), Vesicular stomatitis virus (VSV), Herpes simplex virus (HSV), Coxsackie virus, and Enterovirus (EV-71) on epithelial (HEK293T/HeLa) and immune (RAW264.7) cells. Such inhibition can be described by the induction of the antiviral state in cells by antiviral, IFNrelated gene induction and secretion of IFNs and pro-inflammatory cytokines. In vivo, Angelica tenuissima Nakai treated BALB/c mice displayed higher survivability and lower lung viral titers when challenged with lethal doses of highly pathogenic influenza A subtypes (H1N1, H5N2, H7N3, and H9N2). We also found that Angelica tenuissima Nakai can induce the secretion of IL-6, IFN-λ, and local IgA in bronchoalveolar lavage fluid (BALF) of Angelica tenuissima Nakai treated mice, which correlating with the observed prophylactic effects. In HPLC analysis, we found the presence of several compounds in the aqueous fraction and among them; we evaluated antiviral properties of ferulic acid. Therefore, an extract of Angelica tenuissima Nakai and its components, including ferulic acid, play roles as immunomodulators and may be potential candidates for novel anti-viral/anti-influenza agents. PMID:26727903

  5. Kappa opioid receptor activation alleviates experimental autoimmune encephalomyelitis and promotes oligodendrocyte-mediated remyelination.

    Science.gov (United States)

    Du, Changsheng; Duan, Yanhui; Wei, Wei; Cai, Yingying; Chai, Hui; Lv, Jie; Du, Xiling; Zhu, Jian; Xie, Xin

    2016-01-01

    Multiple sclerosis (MS) is characterized by autoimmune damage to the central nervous system. All the current drugs for MS target the immune system. Although effective in reducing new lesions, they have limited effects in preventing the progression of disability. Promoting oligodendrocyte-mediated remyelination and recovery of neurons are the new directions of MS therapy. The endogenous opioid system, consisting of MOR, DOR, KOR and their ligands, has been suggested to participate in the pathogenesis of MS. However, the exact receptor and mechanism remain elusive. Here we show that genetic deletion of KOR exacerbates experimental autoimmune encephalomyelitis, whereas activating KOR with agonists alleviates the symptoms. KOR does not affect immune cell differentiation and function. Instead, it promotes oligodendrocyte differentiation and myelination both in vitro and in vivo. Our study suggests that targeting KOR might be an intriguing way to develop new MS therapies that may complement the existing immunosuppressive approaches. PMID:27040771

  6. Dioxin mediates downregulation of the reduced folate carrier transport activity via the arylhydrocarbon receptor signalling pathway

    International Nuclear Information System (INIS)

    Dioxins such as 2,3,7,8-tetrachlordibenzo-p-dioxin (TCDD) are common environmental contaminants known to regulate several genes via activation of the transcription factor aryl hydrocarbon receptor (AhR) associated with the development of numerous adverse biological effects. However, comparatively little is known about the molecular mechanisms by which dioxins display their toxic effects in vertebrates. The 5' untranslated region of the hepatocellular Reduced folate carrier (Rfc1; Slc19a1) exhibits AhR binding sites termed dioxin responsive elements (DRE) that have as yet only been found in the promoter region of prototypical TCDD target genes. Rfc1 mediated transport of reduced folates and antifolate drugs such as methotrexate (MTX) plays an essential role in physiological folate homeostasis and MTX cancer chemotherapy. In order to determine whether this carrier represents a target gene of dioxins we have investigated the influence of TCDD on functional Rfc1 activity in rat liver. Pre-treatment of rats with TCDD significantly diminished hepatocellular Rfc1 uptake activity in a time- and dose-dependent manner. In further mechanistic studies we demonstrated that this reduction was due to TCDD-dependent activation of the AhR signalling pathway. We additionally showed that binding of the activated receptor to DRE motifs in the Rfc1 promoter resulted in downregulation of Rfc1 gene expression and reduced carrier protein levels. As downregulation of pivotal Rfc1 activity results in functional folate deficiency associated with an elevated risk of cardiovascular diseases or carcinogenesis, our results indicate that deregulation of this essential transport pathway represents a novel regulatory mechanism how dioxins display their toxic effects through the Ah receptor.

  7. GPER inhibits diabetes-mediated RhoA activation to prevent vascular endothelial dysfunction.

    Science.gov (United States)

    Li, Zilin; Cheng, Liang; Liang, Hongliang; Duan, Weixun; Hu, Jing; Zhi, Weiwei; Yang, Jinbao; Liu, Zhenhua; Zhao, Minggao; Liu, Jincheng

    2016-02-01

    The effect of estrogen receptors on diabetes-induced vascular dysfunction is critical, but ambiguous. Individuals with diabetic vascular disease may require estrogen receptor-specific targeted therapy in the future. The G protein-coupled estrogen receptor (GPER) has beneficial effects on vascular function. However, its fundamental mechanisms are unclear. The RhoA/Rho-kinase pathway contributes to diabetic vascular complications, whereas estrogen can suppress Rho-kinase function. Thus, we assumed that GPER inhibits diabetes-mediated RhoA activation to prevent vascular dysfunction. We further investigated the underlying mechanisms involved in this process. Vascular endothelial cells and ex vivo cultured ovariectomized (OVX) C57BL/6 mouse aortae were treated with high glucose (HG) alone or in combination with GPER agonist (G1). G1 treatment was also administered to OVX db/db mice for 8 weeks. An ex-vivo isovolumic myograph was used to analyze the endothelium-dependent vasodilation and endothelium-independent contraction of mouse aortae. Apoptosis, oxidative stress, and inflammation were attenuated in G1-pretreated vascular endothelial cells. G1 significantly decreased the phosphorylation of inhibitory endothelial nitric oxide (NO) synthase residue threonine 495 (eNOS Thr495), inhibited RhoA expression, and increased NO production. Additionally, G1 rescued the impaired endothelium-dependent relaxation and inhibited RhoA activation in the thoracic aorta of OVX db/db mice and ex-vivo cultured OVX C57BL/6 mouse aortae treated with HG. Estrogens acting via GPER could protect vascular endothelium, and GPER activation might elicit ERα-independent effect to inhibit RhoA/Rho-kinase pathway. Additionally, GPER activation might reduce vascular smooth muscle contraction by inhibiting RhoA activation. Thus, the results of the present study suggest a new therapeutic paradigm for end-stage vascular dysfunction by inhibiting RhoA/Rho-kinase pathway via GPER activation. PMID:26785611

  8. The Mechanosensory Lateral Line System Mediates Activation of Socially-Relevant Brain Regions during Territorial Interactions

    Science.gov (United States)

    Butler, Julie M.; Maruska, Karen P.

    2016-01-01

    Animals use multiple senses during social interactions and must integrate this information in the brain to make context-dependent behavioral decisions. For fishes, the largest group of vertebrates, the mechanosensory lateral line system provides crucial hydrodynamic information for survival behaviors, but little is known about its function in social communication. Our previous work using the African cichlid fish, Astatotilapia burtoni, provided the first empirical evidence that fish use their lateral line system to detect water movements from conspecifics for mutual assessment and behavioral choices. It is unknown, however, where this socially-relevant mechanosensory information is processed in the brain to elicit adaptive behavioral responses. To examine for the first time in any fish species which brain regions receive contextual mechanosensory information, we quantified expression of the immediate early gene cfos as a proxy for neural activation in sensory and socially-relevant brain nuclei from lateral line-intact and -ablated fish following territorial interactions. Our in situ hybridization results indicate that in addition to known lateral line processing regions, socially-relevant mechanosensory information is processed in the ATn (ventromedial hypothalamus homolog), Dl (putative hippocampus homolog), and Vs (putative medial extended amygdala homolog). In addition, we identified a functional network within the conserved social decision-making network (SDMN) whose co-activity corresponds with mutual assessment and behavioral choice. Lateral line-intact and –ablated fight winners had different patterns of co-activity of these function networks and group identity could be determined solely by activation patterns, indicating the importance of mechanoreception to co-activity of the SDMN. These data show for the first time that the mechanosensory lateral line system provides relevant information to conserved decision-making centers of the brain during

  9. The Mechanosensory Lateral Line System Mediates Activation of Socially-Relevant Brain Regions during Territorial Interactions.

    Science.gov (United States)

    Butler, Julie M; Maruska, Karen P

    2016-01-01

    Animals use multiple senses during social interactions and must integrate this information in the brain to make context-dependent behavioral decisions. For fishes, the largest group of vertebrates, the mechanosensory lateral line system provides crucial hydrodynamic information for survival behaviors, but little is known about its function in social communication. Our previous work using the African cichlid fish, Astatotilapia burtoni, provided the first empirical evidence that fish use their lateral line system to detect water movements from conspecifics for mutual assessment and behavioral choices. It is unknown, however, where this socially-relevant mechanosensory information is processed in the brain to elicit adaptive behavioral responses. To examine for the first time in any fish species which brain regions receive contextual mechanosensory information, we quantified expression of the immediate early gene cfos as a proxy for neural activation in sensory and socially-relevant brain nuclei from lateral line-intact and -ablated fish following territorial interactions. Our in situ hybridization results indicate that in addition to known lateral line processing regions, socially-relevant mechanosensory information is processed in the ATn (ventromedial hypothalamus homolog), Dl (putative hippocampus homolog), and Vs (putative medial extended amygdala homolog). In addition, we identified a functional network within the conserved social decision-making network (SDMN) whose co-activity corresponds with mutual assessment and behavioral choice. Lateral line-intact and -ablated fight winners had different patterns of co-activity of these function networks and group identity could be determined solely by activation patterns, indicating the importance of mechanoreception to co-activity of the SDMN. These data show for the first time that the mechanosensory lateral line system provides relevant information to conserved decision-making centers of the brain during territorial

  10. Activity-mediated plasticity of GABA equilibrium potential in rat hippocampal CA1 neurons.

    Science.gov (United States)

    Yang, B; Tadavarty, R; Xu, J-Y; Sastry, B R

    2010-01-01

    The equilibrium potential (E(GABA)(-PSC)) for gamma-aminobutyric acid (GABA) A receptor mediated inhibitory postsynaptic currents (PSCs) in hippocampal CA1 pyramidal neurons shifts when theta-burst stimulation (four pulses at 100 Hz in each burst in a train consisting of five bursts with an inter-burst interval of 200 ms, the train repeated thrice at 30-s intervals) is applied to the input. E(GABA)(-PSC) is regulated by K(+)/Cl(-) co-transporter (KCC2). GABA(B) receptors are implicated in modulating KCC2 levels. In the current study, the involvement of KCC2, as well as GABA(B) receptors, in theta-burst-mediated shifts in E(GABA)(-PSC) was examined. Whole-cell patch recordings were made from hippocampal CA1 pyramidal neurons (from 9 to 12 days old rats), in a slice preparation. Glutamatergic excitatory postsynaptic currents were blocked with dl-2-amino-5-phosphonovaleric acid (50 microM) and 6,7-dinitroquinoxaline-2,3-dione (20 microM). The PSC and the E(GABA)(-PSC) were stable when stimulated at 0.05 Hz. However, both changed following a 30-min stimulation at 0.5 or 1 Hz. Furosemide (500 microM) and KCC2 anti-sense in the recording pipette but not bumetanide (20 or 100 microM) or KCC2 sense, blocked the changes, suggesting KCC2 involvement. Theta-burst stimulation induced a negative shift in E(GABA)(-PSC), which was prevented by KCC2 anti-sense; however, KCC2 sense had no effect. CGP55845 (2 microM), a GABA(B) antagonist, applied in the superfusing medium, or GDP-beta-S in the recording pipette, blocked the shift in E(GABA)(-PSC). These results indicate that activity-mediated plasticity in E(GABA)(-PSC) occurs in hippocampal CA1 pyramidal neurons and theta-burst-induced negative shift in E(GABA)(-PSC) requires KCC2, GABA(B) receptors and G-protein activation. PMID:19879261

  11. Associations between children's social functioning and physical activity participation are not mediated by social acceptance: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Brockman Rowan

    2011-09-01

    Full Text Available Abstract Background Physical activity (PA during childhood often occurs in social contexts. As such, children's ability to develop and maintain friendship groups may be important in understanding their PA. This paper investigates the associations among children's social functioning, and physical activity and whether perceptions of social acceptance mediate any social functioning-PA association. Methods A cross sectional survey in which 652 10-11 year olds self-reported their peer (e.g. difficulties with friends and conduct (e.g. anger/aggression problems, prosocial behaviours (e.g. being kind to others and perceptions of social acceptance. Physical activity was objectively assessed by Actigraph GT1M accelerometers to estimate counts per minute, (CPM and minutes of moderate-to-vigorous physical activity (MVPA. Linear regression analyses were conducted to investigate associations between social functioning and PA. Indirect effects were analysed to explore mediation by social acceptance. Results Among boys, peer problems were negatively associated with CPM and MVPA and conduct problems were positively associated with CPM and MVPA. Prosocial behaviour was unrelated to PA in boys. Social functioning was not associated with PA among girls. Social acceptance did not mediate the social functioning-PA relationship. Conclusions Boys' conduct and peer problems were associated positively and negatively respectively with their PA but this relationship was not mediated by perceptions of social acceptance. Future research should study alternative mediators to understand the processes underpinning this relationship.

  12. Histone H4 Lys 20 methyltransferase SET8 promotes androgen receptor-mediated transcription activation in prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Lushuai [Laboratory of Genome Variations and Precision Bio-Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Yanyan; Du, Fengxia [Laboratory of Genome Variations and Precision Bio-Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101 (China); Han, Xiao [Laboratory of Genome Variations and Precision Bio-Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Li, Xiaohua [Laboratory of Genome Variations and Precision Bio-Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101 (China); Niu, Yuanjie [Chawnshang Chang Sex Hormone Research Center, Tianjin Institute of Urology, Tianjin Medical University, Tianjin 300070 (China); Ren, Shancheng, E-mail: renshancheng@gmail.com [Department of Urology, Shanghai Changhai Hospital, Second Military Medical University, Shanghai 200433 (China); Sun, Yingli, E-mail: sunyl@big.ac.cn [Laboratory of Genome Variations and Precision Bio-Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101 (China)

    2014-07-18

    Highlights: • Dihydrotestosterone stimulates H4K20me1 enrichment at the PSA promoter. • SET8 promotes AR-mediated transcription activation. • SET8 interacts with AR and promotes cell proliferation. - Abstract: Histone methylation status in different lysine residues has an important role in transcription regulation. The effect of H4K20 monomethylation (H4K20me1) on androgen receptor (AR)-mediated gene transcription remains unclear. Here we show that AR agonist stimulates the enrichment of H4K20me1 and SET8 at the promoter of AR target gene PSA in an AR dependent manner. Furthermore, SET8 is crucial for the transcription activation of PSA. Co-immunoprecipitation analyses demonstrate that SET8 interacts with AR. Therefore, we conclude that SET8 is involved in AR-mediated transcription activation, possibly through its interaction with AR and H4K20me1 modification.

  13. HSF1 transcriptional activity mediates alcohol induction of Vamp2 expression and GABA release

    Directory of Open Access Journals (Sweden)

    Florence P. Varodayan

    2013-12-01

    Full Text Available Many central synapses are highly sensitive to alcohol, and it is now accepted that short-term alterations in synaptic function may lead to longer term changes in circuit function. The regulation of postsynaptic receptors by alcohol has been well studied, but the mechanisms underlying the effects of alcohol on the presynaptic terminal are relatively unexplored. To identify a pathway by which alcohol regulates neurotransmitter release, we recently investigated the mechanism by which ethanol induces the Vamp2 gene, but not Vamp1, in mouse primary cortical cultures. These two genes encode isoforms of synaptobrevin, a vesicular soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE protein required for synaptic vesicle fusion. We found that alcohol activates the transcription factor heat shock factor 1 (HSF1 to induce Vamp2 gene expression, while Vamp1 mRNA levels remain unaffected. As the Vamp2 gene encodes a SNARE protein, we then investigated whether ethanol exposure and HSF1 transcriptional activity alter neurotransmitter release using electrophysiology. We found that alcohol increased the frequency of γ-aminobutyric acid (GABA-mediated miniature IPSCs via HSF1, but had no effect on mEPSCs. Overall, these data indicate that alcohol induces HSF1 transcriptional activity to trigger a specific coordinated adaptation in GABAergic presynaptic terminals. This mechanism could explain some of the changes in synaptic function that occur soon after alcohol exposure, and may underlie some of the more enduring effects of chronic alcohol intake on local circuit function.

  14. Lamin A Is an Endogenous SIRT6 Activator and Promotes SIRT6-Mediated DNA Repair

    Directory of Open Access Journals (Sweden)

    Shrestha Ghosh

    2015-11-01

    Full Text Available The nuclear lamins are essential for various molecular events in the nucleus, such as chromatin organization, DNA replication, and provision of mechanical support. A specific point mutation in the LMNA gene creates a truncated prelamin A termed progerin, causing Hutchinson-Gilford progeria syndrome (HGPS. SIRT6 deficiency leads to defective genomic maintenance and accelerated aging similar to HGPS, suggesting a potential link between lamin A and SIRT6. Here, we report that lamin A is an endogenous activator of SIRT6 and facilitates chromatin localization of SIRT6 upon DNA damage. Lamin A promotes SIRT6-dependent DNA-PKcs (DNA-PK catalytic subunit recruitment to chromatin, CtIP deacetylation, and PARP1 mono-ADP ribosylation in response to DNA damage. The presence of progerin jeopardizes SIRT6 activation and compromises SIRT6-mediated molecular events in response to DNA damage. These data reveal a critical role for lamin A in regulating SIRT6 activities, suggesting that defects in SIRT6 functions contribute to impaired DNA repair and accelerated aging in HGPS.

  15. Brain's reward circuits mediate itch relief. a functional MRI study of active scratching.

    Directory of Open Access Journals (Sweden)

    Alexandru D P Papoiu

    Full Text Available Previous brain imaging studies investigating the brain processing of scratching used an exogenous intervention mimicking scratching, performed not by the subjects themselves, but delivered by an investigator. In real life, scratching is a conscious, voluntary, controlled motor response to itching, which is directed to the perceived site of distress. In this study we aimed to visualize in real-time by brain imaging the core mechanisms of the itch-scratch cycle when scratching was performed by subjects themselves. Secondly, we aimed to assess the correlations between brain patterns of activation and psychophysical ratings of itch relief or pleasurability of scratching. We also compared the patterns of brain activity evoked by self-scratching vs. passive scratching. We used a robust tridimensional Arterial Spin Labeling fMRI technique that is less sensitive to motion artifacts: 3D gradient echo and spin echo (GRASE--Propeller. Active scratching was accompanied by a higher pleasurability and induced a more pronounced deactivation of the anterior cingulate cortex and insula, in comparison with passive scratching. A significant involvement of the reward system including the ventral tegmentum of the midbrain, coupled with a mechanism deactivating the periaqueductal gray matter (PAG, suggests that itch modulation operates in reverse to the mechanism known to suppress pain. Our findings not only confirm a role for the central networks processing reward in the pleasurable aspects of scratching, but also suggest they play a role in mediating itch relief.

  16. CaMKII mediates recruitment and activation of the deubiquitinase CYLD at the postsynaptic density.

    Directory of Open Access Journals (Sweden)

    Soe Thein

    Full Text Available NMDA treatment of cultured hippocampal neurons causes recruitment of CYLD, as well as CaMKII, to the postsynaptic density (PSD, as shown by immunoelectron microscopy. Recruitment of CYLD, a deubiquitinase specific for K63-linked polyubiquitins, is blocked by pre-treatment with tatCN21, a CaMKII inhibitor, at a concentration that inhibits the translocation of CaMKII to the PSD. Furthermore, CaMKII co-immunoprecipitates with CYLD from solubilized PSD fractions, indicating an association between the proteins. Purified CaMKII phosphorylates CYLD on at least three residues (S-362, S-418, and S-772 on the human CYLD protein Q9NQC7-1 and promotes its deubiquitinase activity. Activation of CaMKII in isolated PSDs promotes phosphorylation of CYLD on the same residues and also enhances endogenous deubiquitinase activity specific for K63-linked polyubiquitins. Since K63-linked polyubiquitin conjugation to proteins inhibits their interaction with proteasomes, CaMKII-mediated recruitment and upregulation of CYLD is expected to remove K63-linked polyubiquitins and facilitate proteasomal degradation at the PSD.

  17. The Association between leisure time physical activity and smoking in adolescence: an examination of potential mediating and moderating factors

    DEFF Research Database (Denmark)

    Verkooijen, Kirsten; Nielsen, Gert A; Kremers, Stef P J

    2008-01-01

    , sense of coherence, and physically active self-concept as potential mediating and moderating variables. METHOD: Data were obtained through a postal survey among 3,940 Danes aged 16 to 20. Bivariate and multivariate logistic regressions were performed to identify significant associations as well as...... disappeared. Further analyses revealed that physically active self-concept acted both as a mediator and as a moderator of the studied relationship. CONCLUSION: The data suggest that participation in leisure time physical activity is indeed inversely associated with adolescent smoking, but only when physical...... activity is perceived as an important part of the self. Hence, interventions designed to promote physical activity among youth may also aim to boost physically active self-concepts....

  18. Effect of exercise training on the renin-angiotensin-aldosterone system in healthy individuals: a systematic review and meta-analysis.

    Science.gov (United States)

    Goessler, Karla; Polito, Marcos; Cornelissen, Véronique Ann

    2016-03-01

    The aim of this systematic review and meta-analysis was to evaluate the effect of exercise training on parameters of the renin-angiotensin-aldosterone system (RAAS) in healthy adults, and to investigate the relation with training induced changes in blood pressure. A systematic search was conducted and we included randomized controlled trials lasting ⩾4 weeks investigating the effects of exercise on parameters of the RAAS in healthy adults (age ⩾18 years) and published in a peer-reviewed journal up to December 2013. Fixed effects models were used and data are reported as weighted means and 95% confidence limits (CL). Eleven randomized controlled trials with a total of 375 individuals were included. Plasma renin activity was reduced after exercise training (n= 7 trials, standardized mean difference -0.25 (95% CL -0.5 to -0.001), P=0.049), whereas no effect was observed on serum aldosterone ((n= 3 trials; standardized mean difference -0.79 (-1.97 to +0.39)) or angiotensin II (n=3 trials; standardized mean difference -0.16 (-0.61 to +0.30). Significant reductions in systolic blood pressure -5.65 mm Hg (-8.12 to -3.17) and diastolic blood pressure -3.64 mm Hg (-5.4 to -1.91) following exercise training were observed. No relation was found between net changes in plasma renin activity and net changes in blood pressure (P>0.05). To conclude, although we observed a significant reduction in plasma renin activity following exercise training this was not related to the observed blood pressure reduction. Given the small number of studies and small sample sizes, larger well-controlled randomized studies are required to confirm our results and to investigate the potential role of the RAAS in the observed improvements in blood pressure following exercise training. PMID:26399454

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

    Science.gov (United States)

    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. PMID:24222656

  20. Reduced plasma aldosterone concentrations in randomly selected patients with insulin-dependent diabetes mellitus.

    LENUS (Irish Health Repository)

    Cronin, C C

    2012-02-03

    Abnormalities of the renin-angiotensin system have been reported in patients with diabetes mellitus and with diabetic complications. In this study, plasma concentrations of prorenin, renin, and aldosterone were measured in a stratified random sample of 110 insulin-dependent (Type 1) diabetic patients attending our outpatient clinic. Fifty-four age- and sex-matched control subjects were also examined. Plasma prorenin concentration was higher in patients without complications than in control subjects when upright (geometric mean (95% confidence intervals (CI): 75.9 (55.0-105.6) vs 45.1 (31.6-64.3) mU I-1, p < 0.05). There was no difference in plasma prorenin concentration between patients without and with microalbuminuria and between patients without and with background retinopathy. Plasma renin concentration, both when supine and upright, was similar in control subjects, in patients without complications, and in patients with varying degrees of diabetic microangiopathy. Plasma aldosterone was suppressed in patients without complications in comparison to control subjects (74 (58-95) vs 167 (140-199) ng I-1, p < 0.001) and was also suppressed in patients with microvascular disease. Plasma potassium was significantly higher in patients than in control subjects (mean +\\/- standard deviation: 4.10 +\\/- 0.36 vs 3.89 +\\/- 0.26 mmol I-1; p < 0.001) and plasma sodium was significantly lower (138 +\\/- 4 vs 140 +\\/- 2 mmol I-1; p < 0.001). We conclude that plasma prorenin is not a useful early marker for diabetic microvascular disease. Despite apparently normal plasma renin concentrations, plasma aldosterone is suppressed in insulin-dependent diabetic patients.

  1. Dual Blockade of the Renin-angiotensin-aldosterone System in Type 2 Diabetic Kidney Disease

    Institute of Scientific and Technical Information of China (English)

    Yan-Huan Feng; Ping Fu

    2016-01-01

    Objective: To examine the efficacy and safety of dual blockade of the renin-angiotensin-aldosterone system (RAAS) among patients with type 2 diabetic kidney disease.Data Sources: We searched the major literature repositories, including the Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE, for randomized clinical trials published between January 1990 and October 2015 that compared the efficacy and safety of the use of dual blockade of the RAAS versus the use ofmonotherapy, without applying any language restrictions.Keywords for the searches included "diabetic nephropathy," "chronic kidney disease," "chronic renal insufficiency," "diabetes mellitus," "dual therapy," "combined therapy,""dual blockade," "renin-angiotensin system," "angiotensin-converting enzyme inhibitor," "angiotensin-receptor blocker," "aldosterone blockade," "selective aldosterone blockade," "renin inhibitor," "direct renin inhibitor," "mineralocorticoid receptor blocker," etc.Study Selection: The selected articles were carefully reviewed.We excluded randomized clinical trials in which the kidney damage of patients was related to diseases other than diabetes mellitus.Results: Combination treatment with an angiotensin-converting enzyme inhibitor supplemented by an angiotensin Ⅱ receptor blocking agent is expected to provide a more complete blockade of the RAAS and a better control of hypertension.However, existing literature has presented mixed results, in particular, related to patient safety.In view of this, we conducted a comprehensive literature review in order to explain the rationale for dual blockade of the RAAS, and to discuss the pros and cons.Conclusions: Despite the negative results of some recent large-scale studies, it may be immature to declare that the dual blockade is a failure because of the complex nature of the RAAS surrounding its diversified functions and utility.Further trials are warranted to study the combination therapy as an evidence-based practice.

  2. Hypokalemic myopathy associated with primary aldosteronism and glycyrrhizine-induced pseudoaldosteronism.

    Science.gov (United States)

    Ishikawa, S; Saito, T; Okada, K; Atsumi, T; Kuzuya, T

    1985-12-01

    Enzymatic and histological features of muscular disorders associated with primary aldosteronism and glycyrrhizine-induced pseudoaldosteronism were studied. Among 10 patients with primary aldosteronism and 3 patients with pseudoaldosteronism, 5 patients were admitted to our hospital because of muscular weakness. The serum potassium (K) level was 1.86 +/- 0.21 mEq/l in a myopathy group on admission, a value significantly less than that of the 2.74 +/- 0.10 mEq/l in a non-myopathy group (p less than 0.01). Serum creatine phosphokinase (CPK), glutamate-oxyloacetate transaminase (GOT), and lactate dehydrogenase (LDH) were increased in the myopathy group compared to the non-myopathy group; serum CPK was 1412.6 +/- 902.6 vs. 22.8 +/- 5.0 mU/ml, serum GOT was 186.4 +/- 75.3 vs. 24.2 +/- 5.4 mU/ml (p less than 0.05), and serum LDH was 1133.4 +/- 377.3 vs. 387.6 +/- 42.5 mU/ml (p less than 0.05) in the groups with and without myopathy. Analysis of CPK isozymes revealed that the MM type exceeded 95%. The elevated serum CPK, GOT and LDH rapidly decreased to the normal range and muscular strength completely improved within 6 to 13 days after hospitalization, when the serum K level remained below than normal. Light microscopic finding of damaged muscle showed the diffuse necrosis and vacuolization of muscle fibers. Electron microscopic study clearly demonstrated complete dissolution of myofilaments with disappearance of sarcoplasmic reticulum and T-tubules in the necrotic muscle fibers. These results indicate that muscular lesions may occur in primary aldosteronism and pseudoaldosteronism when the serum K level is decreased to below 2.0 mEq/l. This myopathy is not periodic paralysis but hypokalemic myopathy. The mechanism by which K deficiency causes muscular damage remains unknown. PMID:3914413

  3. Dual Blockade of the Renin-angiotensin-aldosterone System in Type 2 Diabetic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Yan-Huan Feng

    2016-01-01

    Full Text Available Objective: To examine the efficacy and safety of dual blockade of the renin-angiotensin-aldosterone system (RAAS among patients with type 2 diabetic kidney disease. Data Sources: We searched the major literature repositories, including the Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE, for randomized clinical trials published between January 1990 and October 2015 that compared the efficacy and safety of the use of dual blockade of the RAAS versus the use of monotherapy, without applying any language restrictions. Keywords for the searches included "diabetic nephropathy," "chronic kidney disease," "chronic renal insufficiency," "diabetes mellitus," "dual therapy," "combined therapy," "dual blockade," "renin-angiotensin system," "angiotensin-converting enzyme inhibitor," "angiotensin-receptor blocker," "aldosterone blockade," "selective aldosterone blockade," "renin inhibitor," "direct renin inhibitor," "mineralocorticoid receptor blocker," etc. Study Selection: The selected articles were carefully reviewed. We excluded randomized clinical trials in which the kidney damage of patients was related to diseases other than diabetes mellitus. Results: Combination treatment with an angiotensin-converting enzyme inhibitor supplemented by an angiotensin II receptor blocking agent is expected to provide a more complete blockade of the RAAS and a better control of hypertension. However, existing literature has presented mixed results, in particular, related to patient safety. In view of this, we conducted a comprehensive literature review in order to explain the rationale for dual blockade of the RAAS, and to discuss the pros and cons. Conclusions: Despite the negative results of some recent large-scale studies, it may be immature to declare that the dual blockade is a failure because of the complex nature of the RAAS surrounding its diversified functions and utility. Further trials are warranted to study the combination therapy as an

  4. Histone acetyltransferase (HAT) activity of p300 modulates human T lymphotropic virus type 1 p30II-mediated repression of LTR transcriptional activity

    International Nuclear Information System (INIS)

    Human T-lymphotropic virus type-1 (HTLV-1) is a deltaretrovirus that causes adult T cell leukemia/lymphoma, and is implicated in a variety of lymphocyte-mediated inflammatory disorders. HTLV-1 provirus has regulatory and accessory genes in four pX open reading frames. HTLV-1 pX ORF-II encodes two proteins, p13II and p30II, which are incompletely defined in virus replication or pathogenesis. We have demonstrated that pX ORF-II mutations block virus replication in vivo and that ORF-II encoded p30II, a nuclear-localizing protein that binds with CREB-binding protein (CBP)/p300, represses CREB and Tax responsive element (TRE)-mediated transcription. Herein, we have identified p30II motifs important for p300 binding and in regulating TRE-mediated transcription in the absence and presence of HTLV-1 provirus. Within amino acids 100-179 of p30II, a region important for repression of LTR-mediated transcription, we identified a single lysine residue at amino acid 106 (K3) that significantly modulates the ability of p30II to repress TRE-mediated transcription. Exogenous p300, in a dose-responsive manner, reverses p30II-dependent repression of TRE-mediated transcription, in the absence or presence of the provirus, In contrast to wild type p300, p300 HAT mutants (defective in histone acetyltransferase activity) only partially rescued p30II-mediated LTR repression. Deacetylation by histone deacetylase-1 (HDAC-1) enhanced p30II-mediated LTR repression, while inhibition of deacetylation by trichostatin A decreases p30II-mediated LTR repression. Collectively, our data indicate that HTLV-1 p30II modulates viral gene expression in a cooperative manner with p300-mediated acetylation

  5. Activation of NF-κB mediates astrocyte swelling and brain edema in traumatic brain injury.

    Science.gov (United States)

    Jayakumar, Arumugam R; Tong, Xiao Y; Ruiz-Cordero, Roberto; Bregy, Amade; Bethea, John R; Bramlett, Helen M; Norenberg, Michael D

    2014-07-15

    Brain edema and associated increased intracranial pressure are major consequences of traumatic brain injury (TBI). While astrocyte swelling (cytotoxic edema) represents a major component of the brain edema in the early phase of TBI, its mechanisms are unclear. One factor known to be activated by trauma is nuclear factor-κB (NF-κB). Because this factor has been implicated in the mechanism of cell swelling/brain edema in other neurological conditions, we examined whether NF-κB might also be involved in the mediation of post-traumatic astrocyte swelling/brain edema. Here we show an increase in NF-κB activation in cultured astrocytes at 1 and 3 h after trauma (fluid percussion injury, FPI), and that BAY 11-7082, an inhibitor of NF-κB, significantly blocked the trauma-induced astrocyte swelling. Increased activities of nicotinamide adenine dinucleotide phosphate-oxidase and the Na(+), K(+), 2Cl(-) cotransporter were also observed in cultured astrocytes after trauma, and BAY 11-7082 reduced these effects. We also examined the role of NF-κB in the mechanism of cell swelling by using astrocyte cultures derived from transgenic (Tg) mice with a functional inactivation of astrocytic NF-κB. Exposure of cultured astrocytes from wild-type mice to in vitro trauma (3 h) caused a significant increase in cell swelling. By contrast, traumatized astrocyte cultures derived from NF-κB Tg mice showed no swelling. We also found increased astrocytic NF-κB activation and brain water content in rats after FPI, while BAY 11-7082 significantly reduced such effects. Our findings strongly suggest that activation of astrocytic NF-κB represents a key element in the process by which cytotoxic brain edema occurs after TBI. PMID:24471369

  6. Reduced insulin-mediated citrate synthase activity in cultured skeletal muscle cells from patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Ørtenblad, Niels; Mogensen, Martin; Petersen, Ingrid;

    2005-01-01

    In myotubes established from patients with type 2 diabetes (T2D), lipid oxidation and insulin-mediated glucose oxidation are reduced, whereas in myotubes from obese non-diabetic subjects, exposure to palmitate impairs insulin-mediated glucose oxidation. To determine the underlying mechanisms of...... obese subjects and T2D patients. Basal CS activity was lower (14%) in diabetic myotubes compared with myotubes from lean controls (P=0.03). Incubation with insulin (1 microM) for 4 h increased the CS activity (26-33%) in myotubes from both lean (P=0.02) and obese controls (P<0.001), but not from...

  7. Avoidance of activity and disability in patients with osteoarthritis of the knee: the mediating role of muscle strength.

    OpenAIRE

    Steultjens, M.P.M.; Dekker, J; Bijlsma, J. W. J.

    2002-01-01

    OBJECTIVE: Avoidance of activity is hypothesized to lead to muscle weakness and consequently, to physical disability. This study was undertaken to validate the avoidance model by providing evidence for the mediating role of muscle weakness in the relationship between avoidance of activity and physical disability in patients with osteoarthritis (OA) of the knee. METHODS: Data on avoidance of activity, observed physical disability, and muscle strength of the knee in 107 patients with knee OA we...

  8. Whole body computed tomographic findings of each one case with primary aldosteronism and Cushing syndrome

    International Nuclear Information System (INIS)

    We here report each one case with primary aldosteronism (male, 28 years old) and Cushing syndrome (female, 37 years old). Both of the cases showed characteristic clinical signs of hypertension and typical laboratory findings of adreno-hormonal assays. In performance of whole body computed tomography, clear pictures of tumorous adenomas in both cases were taken and the sizes of adenomas in picture were completely same as the masses obtained by the lateral adrenectomies. As a result, the whole body computed tomography is very useful to diagnose the diseases of adrenal adenoma and hyperplasia. (author)

  9. The first laparoscopic resection of an aldosterone-secreting adrenocortical oncocytoma in a child

    Directory of Open Access Journals (Sweden)

    Melih Akin

    2014-09-01

    Full Text Available Oncocytomas of the adrenal cortex are usually benign and nonfunctional, consisting of oncocytes in which the cytoplasm becomes eosinophilic due to the accumulation of abnormal mitochondria. Oncocytomas can exist in many organs and are frequently found in the salivary gland, kidneys, thyroid gland, parathyroid gland, and hypophysis. Functioning oncocytomas are very rarely observed in children, and no more than ten cases have been reported in the literature. Here, we present the first report of laparoscopic excision of an aldosterone-secreting adrenocortical oncocytoma in a child.

  10. 肾上腺醛固酮腺瘤大鼠模型的建立%Establishment of a Rat Model of Aldosterone-Producing Adenoma

    Institute of Scientific and Technical Information of China (English)

    闫永吉; 陆义芹; 王保军; 史涛坪; 王光; 张海燕

    2012-01-01

    目的 构建肾上腺醛固酮腺瘤大鼠模型.方法 16只SD大鼠随机分对照组合醛固酮腺瘤组,在ALZET2004的微量渗透泵储药仓内分别注入醛固酮溶液或空白溶剂,然后将其埋于大鼠背部皮下.ALZET2004微量渗透泵可以持续灌注4周,为使醛固酮作用时间达到8周,4周后更换渗透泵1次,同时尾套法测量大鼠尾动脉收缩压;8周后,放免法检测血浆醛固酮浓度和肾素活性.结果 3周后,与对照大鼠相比,腺瘤组大鼠收缩压开始升高,第7周达到顶峰,之后维持在高水平;腺瘤组大鼠血浆醛固酮的浓度显著升高 (P<0.01),肾素活性被抑制 (P<0.01).结论 大鼠皮下埋植微量渗透泵灌注醛固酮,可以成功构建大鼠醛固酮腺瘤模型.%Objective To establish a rat model of aldosterone-producing adenoma (APA). Methods 16 Sprague- Dawley rats subcutaneously implanted with an osmotic mini- pump, were randomly divided into 2 groups: control group (vehicle) and APA (1 μg/h) group. Because the mini- pump (ALZET 2004) could continuously infuse test substance for 4 weeks, another minipump was replaced after the fourth week to make the duration of aldosterone infusion for 8 weeks. Systolic blood pressure (SBP) was measured weekly by the tail-cuff method. At the termination of the study, blood was collected for measurements of plasma renin activity (PRA) and aldosterone concontration (PAC) with radioimmunoassay kits. Results After 3 weeks, APA rats showed significantly and progressively increased SBP compared with controls (P<0.05) , and the SBP level reached peak on 7th week and remained high levels. PRA was substantially depressed and PAC was significantly raised in APA rats (P<0.01) . Conclusion By implanting osmotic minipumps subcutaneously, the rat models of APA can be successfully established, which provide a good platform for investigating the pathogenesis of APA.

  11. Mitochondrial permeabilization without caspase activation mediates the increase of basal apoptosis in cells lacking Nrf2.

    Science.gov (United States)

    Ariza, Julia; González-Reyes, José A; Jódar, Laura; Díaz-Ruiz, Alberto; de Cabo, Rafael; Villalba, José Manuel

    2016-06-01

    Nuclear factor E2-related factor-2 (Nrf2) is a cap'n'collar/basic leucine zipper (b-ZIP) transcription factor which acts as sensor of oxidative and electrophilic stress. Low levels of Nrf2 predispose cells to chemical carcinogenesis but a dark side of Nrf2 function also exists because its unrestrained activation may allow the survival of potentially dangerous damaged cells. Since Nrf2 inhibition may be of therapeutic interest in cancer, and a decrease of Nrf2 activity may be related with degenerative changes associated with aging, it is important to investigate how the lack of Nrf2 function activates molecular mechanisms mediating cell death. Murine Embryonic Fibroblasts (MEFs) bearing a Nrf2 deletion (Nrf2KO) displayed diminished cellular growth rate and shortened lifespan compared with wild-type MEFs. Basal rates of DNA fragmentation and histone H2A.X phosphorylation were higher in Nrf2KO MEFs, although steady-state levels of reactive oxygen species were not significantly increased. Enhanced rates of apoptotic DNA fragmentation were confirmed in liver and lung tissues from Nrf2KO mice. Apoptosis in Nrf2KO MEFs was associated with a decrease of Bcl-2 but not Bax levels, and with the release of the mitochondrial pro-apoptotic factors cytochrome c and AIF. Procaspase-9 and Apaf-1 were also increased in Nrf2KO MEFs but caspase-3 was not activated. Inhibition of XIAP increased death in Nrf2KO but not in wild-type MEFs. Mitochondrial ultrastructure was also altered in Nrf2KO MEFs. Our results support that Nrf2 deletion produces mitochondrial dysfunction associated with mitochondrial permeabilization, increasing basal apoptosis through a caspase-independent and AIF-dependent pathway. PMID:27016073

  12. Laminin α2-mediated focal adhesion kinase activation triggers Alport glomerular pathogenesis.

    Directory of Open Access Journals (Sweden)

    Duane Delimont

    Full Text Available It has been known for some time that laminins containing α1 and α2 chains, which are normally restricted to the mesangial matrix, accumulate in the glomerular basement membranes (GBM of Alport mice, dogs, and humans. We show that laminins containing the α2 chain, but not those containing the α1 chain activates focal adhesion kinase (FAK on glomerular podocytes in vitro and in vivo. CD151-null mice, which have weakened podocyte adhesion to the GBM rendering these mice more susceptible to biomechanical strain in the glomerulus, also show progressive accumulation of α2 laminins in the GBM, and podocyte FAK activation. Analysis of glomerular mRNA from both models demonstrates significant induction of MMP-9, MMP-10, MMP-12, MMPs linked to GBM destruction in Alport disease models, as well as the pro-inflammatory cytokine IL-6. SiRNA knockdown of FAK in cultured podocytes significantly reduced expression of MMP-9, MMP-10 and IL-6, but not MMP-12. Treatment of Alport mice with TAE226, a small molecule inhibitor of FAK activation, ameliorated fibrosis and glomerulosclerosis, significantly reduced proteinuria and blood urea nitrogen levels, and partially restored GBM ultrastructure. Glomerular expression of MMP-9, MMP-10 and MMP-12 mRNAs was significantly reduced in TAE226 treated animals. Collectively, this work identifies laminin α2-mediated FAK activation in podocytes as an important early event in Alport glomerular pathogenesis and suggests that FAK inhibitors, if safe formulations can be developed, might be employed as a novel therapeutic approach for treating Alport renal disease in its early stages.

  13. Somatic modulation of spinal reflex bladder activity mediated by nociceptive bladder afferent nerve fibers in cats.

    Science.gov (United States)

    Xiao, Zhiying; Rogers, Marc J; Shen, Bing; Wang, Jicheng; Schwen, Zeyad; Roppolo, James R; de Groat, William C; Tai, Changfeng

    2014-09-15

    The goal of the present study was to determine if supraspinal pathways are necessary for inhibition of bladder reflex activity induced by activation of somatic afferents in the pudendal or tibial nerve. Cats anesthetized with α-chloralose were studied after acute spinal cord transection at the thoracic T9/T10 level. Dilute (0.25%) acetic acid was used to irritate the bladder, activate nociceptive afferent C-fibers, and trigger spinal reflex bladder contractions (amplitude: 19.3 ± 2.9 cmH2O). Hexamethonium (a ganglionic blocker, intravenously) significantly (P < 0.01) reduced the amplitude of the reflex bladder contractions to 8.5 ± 1.9 cmH2O. Injection of lidocaine (2%, 1-2 ml) into the sacral spinal cord or transection of the sacral spinal roots and spinal cord further reduced the contraction amplitude to 4.2 ± 1.3 cmH2O. Pudendal nerve stimulation (PNS) at frequencies of 0.5-5 Hz and 40 Hz but not at 10-20 Hz inhibited reflex bladder contractions, whereas tibial nerve stimulation (TNS) failed to inhibit bladder contractions at all tested frequencies (0.5-40 Hz). These results indicate that PNS inhibition of nociceptive afferent C-fiber-mediated spinal reflex bladder contractions can occur at the spinal level in the absence of supraspinal pathways, but TNS inhibition requires supraspinal pathways. In addition, this study shows, for the first time, that after acute spinal cord transection reflex bladder contractions can be triggered by activating nociceptive bladder afferent C-fibers using acetic acid irritation. Understanding the sites of action for PNS or TNS inhibition is important for the clinical application of pudendal or tibial neuromodulation to treat bladder dysfunctions. PMID:25056352

  14. covR Mediated Antibiofilm Activity of 3-Furancarboxaldehyde Increases the Virulence of Group A Streptococcus.

    Directory of Open Access Journals (Sweden)

    Ganapathy Ashwinkumar Subramenium

    Full Text Available Group A streptococcus (GAS, Streptococcus pyogenes, a multi-virulent, exclusive human pathogen responsible for various invasive and non-invasive diseases possesses biofilm forming phenomenon as one of its pathogenic armaments. Recently, antibiofilm agents have gained prime importance, since inhibiting the biofilm formation is expected to reduce development of antibiotic resistance and increase their susceptibility to the host immune cells.The current study demonstrates the antibiofilm activity of 3Furancarboxaldehyde (3FCA, a floral honey derived compound, against GAS biofilm, which was divulged using crystal violet assay, light microscopy, and confocal laser scanning microscopy. The report is extended to study its effect on various aspects of GAS (morphology, virulence, aggregation at its minimal biofilm inhibitory concentration (132μg/ml. 3FCA was found to alter the growth pattern of GAS in solid and liquid medium and increased the rate of auto-aggregation. Electron microscopy unveiled the increase in extra polymeric substances around cell. Gene expression studies showed down-regulation of covR gene, which is speculated to be the prime target for the antibiofilm activity. Increased hyaluronic acid production and down regulation of srtB gene is attributed to the enhanced rate of auto-aggregation. The virulence genes (srv, mga, luxS and hasA were also found to be over expressed, which was manifested with the increased susceptibility of the model organism Caenorhabditis elegans to 3FCA treated GAS. The toxicity of 3FCA was ruled out with no adverse effect on C. elegans.Though 3FCA possess antibiofilm activity against GAS, it was also found to increase the virulence of GAS. This study demonstrates that, covR mediated antibiofilm activity may increase the virulence of GAS. This also emphasizes the importance to analyse the acclimatization response and virulence of the pathogen in the presence of antibiofilm compounds prior to their clinical trials.

  15. Endogenous Opiates in the Nucleus Tractus Solitarius Mediate Electroacupuncture-Induced Sleep Activities in Rats

    Directory of Open Access Journals (Sweden)

    Chiung-Hsiang Cheng

    2011-01-01

    Full Text Available Electroacupuncture (EA possesses various therapeutic effects, including alleviation of pain, reduction of inflammation and improvement of sleep disturbance. The mechanisms of EA on sleep improvement, however, remain to be determined. It has been stated in ancient Chinese literature that the Anmian (EX17 acupoint is one of the trigger points that alleviates insomnia. We previously demonstrated that EA stimulation of Anmian acupoints in rats during the dark period enhances non-rapid eye movement (NREM sleep, which involves the induction of cholinergic activity in the nucleus tractus solitarius (NTS. In addition to cholinergic activation of the NTS, activation of the endogenous opioidergic system may also be a mechanism by which acupuncture affects sleep. Therefore, this study was designed to investigate the involvement of the NTS opioidergic system in EA-induced alterations in sleep. Our present results indicate that EA of Anmian acupoints increased NREM sleep, but not rapid eye movement sleep, during the dark period in rats. This enhancement in NREM sleep was dose-dependently blocked by microinjection of opioid receptor antagonist, naloxone, and the μ-opioid receptor antagonist, naloxonazine, into the NTS; administrations of δ-receptor antagonist, natrindole, and the κ-receptor antagonist, nor-binaltrophimine, however, did not affect EA-induced alterations in sleep. Furthermore, β-endorphin was significantly increased in both the brainstem and hippocampus after the EA stimuli, an effect blocked by administration of the muscarinic antagonist scopolamine into the NTS. Our findings suggest that mechanisms of EA-induced NREM sleep enhancement may be mediated, in part, by cholinergic activation, stimulation of the opiodergic neurons to increase the concentrations of β-endorphin and the involvement of the μ-opioid receptors.

  16. Catalyst activation, deactivation, and degradation in palladium-mediated Negishi cross-coupling reactions.

    Science.gov (United States)

    Böck, Katharina; Feil, Julia E; Karaghiosoff, Konstantin; Koszinowski, Konrad

    2015-03-27

    Pd-mediated Negishi cross-coupling reactions were studied by a combination of kinetic measurements, electrospray-ionization (ESI) mass spectrometry, (31)P NMR and UV/Vis spectroscopy. The kinetic measurements point to a rate-determining oxidative addition. Surprisingly, this step seems to involve not only the Pd catalyst and the aryl halide substrate, but also the organozinc reagent. In this context, the ESI-mass spectrometric observation of heterobimetallic Pd-Zn complexes [L2 PdZnR](+) (L=S-PHOS, R=Bu, Ph, Bn) is particularly revealing. The inferred presence of these and related neutral complexes with a direct Pd-Zn interaction in solution explains how the organozinc reagent can modulate the reactivity of the Pd catalyst. Previous theoretical calculations by González-Pérez et al. (Organometallics- 2012, 31, 2053) suggest that the complexation by the organozinc reagent lowers the activity of the Pd catalyst. Presumably, a similar effect also causes the rate decrease observed upon addition of ZnBr2 . In contrast, added LiBr apparently counteracts the formation of Pd-Zn complexes and restores the high activity of the Pd catalyst. At longer reaction times, deactivation processes due to degradation of the S-PHOS ligand and aggregation of the Pd catalyst come into play, thus further contributing to the appreciable complexity of the title reaction. PMID:25709062

  17. Inhibition of Rb Phosphorylation Leads to mTORC2-Mediated Activation of Akt.

    Science.gov (United States)

    Zhang, Jinfang; Xu, Kai; Liu, Pengda; Geng, Yan; Wang, Bin; Gan, Wenjian; Guo, Jianping; Wu, Fei; Chin, Y Rebecca; Berrios, Christian; Lien, Evan C; Toker, Alex; DeCaprio, James A; Sicinski, Piotr; Wei, Wenyi

    2016-06-16

    The retinoblastoma (Rb) protein exerts its tumor suppressor function primarily by inhibiting the E2F family of transcription factors that govern cell-cycle progression. However, it remains largely elusive whether the hyper-phosphorylated, non-E2F1-interacting form of Rb has any physiological role. Here we report that hyper-phosphorylated Rb directly binds to and suppresses the function of mTORC2 but not mTORC1. Mechanistically, Rb, but not p107 or p130, interacts with Sin1 and blocks the access of Akt to mTORC2, leading to attenuated Akt activation and increased sensitivity to chemotherapeutic drugs. As such, inhibition of Rb phosphorylation by depleting cyclin D or using CDK4/6 inhibitors releases Rb-mediated mTORC2 suppression. This, in turn, leads to elevated Akt activation to confer resistance to chemotherapeutic drugs in Rb-proficient cells, which can be attenuated with Akt inhibitors. Therefore, our work provides a molecular basis for the synergistic usage of CDK4/6 and Akt inhibitors in treating Rb-proficient cancer. PMID:27237051

  18. Nuclear localization of Lyn tyrosine kinase mediated by inhibition of its kinase activity

    International Nuclear Information System (INIS)

    Src-family kinases, cytoplasmic enzymes that participate in various signaling events, are found at not only the plasma membrane but also subcellular compartments, such as the nucleus, the Golgi apparatus and late endosomes/lysosomes. Lyn, a member of the Src-family kinases, is known to play a role in DNA damage response and cell cycle control in the nucleus. However, it is still unclear how the localization of Lyn to the nucleus is regulated. Here, we investigated the mechanism of the distribution of Lyn between the cytoplasm and the nucleus in epitheloid HeLa cells and hematopoietic THP-1 cells. Lyn was definitely detected in purified nuclei by immunofluorescence and immunoblotting analyses. Nuclear accumulation of Lyn was enhanced upon treatment of cells with leptomycin B (LMB), an inhibitor of Crm1-mediated nuclear export. Moreover, Lyn mutants lacking the sites for lipid modification were highly accumulated in the nucleus upon LMB treatment. Intriguingly, inhibition of the kinase activity of Lyn by SU6656, Csk overexpression, or point mutation in the ATP-binding site induced an increase in nuclear Lyn levels. These results suggest that Lyn being imported into and rapidly exported from the nucleus preferentially accumulates in the nucleus by inhibition of the kinase activity and lipid modification

  19. p53-mediated activation of the mitochondrial protease HtrA2/Omi prevents cell invasion.

    Science.gov (United States)

    Yamauchi, Shota; Hou, Yan Yan; Guo, Alvin Kunyao; Hirata, Hiroaki; Nakajima, Wataru; Yip, Ai Kia; Yu, Cheng-han; Harada, Ichiro; Chiam, Keng-Hwee; Sawada, Yasuhiro; Tanaka, Nobuyuki; Kawauchi, Keiko

    2014-03-31

    Oncogenic Ras induces cell transformation and promotes an invasive phenotype. The tumor suppressor p53 has a suppressive role in Ras-driven invasion. However, its mechanism remains poorly understood. Here we show that p53 induces activation of the mitochondrial protease high-temperature requirement A2 (HtrA2; also known as Omi) and prevents Ras-driven invasion by modulating the actin cytoskeleton. Oncogenic Ras increases accumulation of p53 in the cytoplasm, which promotes the translocation of p38 mitogen-activated protein kinase (MAPK) into mitochondria and induces phosphorylation of HtrA2/Omi. Concurrently, oncogenic Ras also induces mitochondrial fragmentation, irrespective of p53 expression, causing the release of HtrA2/Omi from mitochondria into the cytosol. Phosphorylated HtrA2/Omi therefore cleaves β-actin and decreases the amount of filamentous actin (F-actin) in the cytosol. This ultimately down-regulates p130 Crk-associated substrate (p130Cas)-mediated lamellipodia formation, countering the invasive phenotype initiated by oncogenic Ras. Our novel findings provide insights into the mechanism by which p53 prevents the malignant progression of transformed cells. PMID:24662565

  20. Nox4 and Duox1/2 Mediate Redox Activation of Mesenchymal Cell Migration by PDGF

    Science.gov (United States)

    Sukhova, Anna A.; Sagaradze, George D.; Albert, Eugene A.; Ageeva, Ludmila V.; Sharonov, George V.; Tkachuk, Vsevolod A.

    2016-01-01

    Platelet derived growth factor (PDGF) orchestrates wound healing and tissue regeneration by regulating recruitment of the precursor mesenchymal stromal cells (MSC) and fibroblasts. PDGF stimulates generation of hydrogen peroxide that is required for cell migration, but the sources and intracellular targets of H2O2 remain obscure. Here we demonstrate sustained live responses of H2O2 to PDGF and identify PKB/Akt, but not Erk1/2, as the target for redox regulation in cultured 3T3 fibroblasts and MSC. Apocynin, cell-permeable catalase and LY294002 inhibited PDGF-induced migration and mitotic activity of these cells indicating involvement of PI3-kinase pathway and H2O2. Real-time PCR revealed Nox4 and Duox1/2 as the potential sources of H2O2. Silencing of Duox1/2 in fibroblasts or Nox4 in MSC reduced PDGF-stimulated intracellular H2O2, PKB/Akt phosphorylation and migration, but had no such effect on Erk1/2. In contrast to PDGF, EGF failed to increase cytoplasmic H2O2, phosphorylation of PKB/Akt and migration of fibroblasts and MSC, confirming the critical impact of redox signaling. We conclude that PDGF-induced migration of mesenchymal cells requires Nox4 and Duox1/2 enzymes, which mediate redox-sensitive activation of PI3-kinase pathway and PKB/Akt. PMID:27110716

  1. ERβ regulation of NF-kB activation in prostate cancer is mediated by HIF-1.

    Science.gov (United States)

    Mak, Paul; Li, Jiarong; Samanta, Sanjoy; Mercurio, Arthur M

    2015-11-24

    We examined the regulation of NF-κB in prostate cancer by estrogen receptor β (ERβ) based on the inverse correlation between p65 and ERβ expression that exists in prostate carcinomas and reports that ERβ can inhibit NF-κB activation, although the mechanism is not known. We demonstrate that ERβ functions as a gate-keeper for NF-κB p65 signaling by repressing its expression and nuclear translocation. ERβ regulation of NF-κB signaling is mediated by HIF-1. Loss of ERβ or hypoxia stabilizes HIF-1α, which we found to be a direct driver of IKKβ transcription through a hypoxia response element present in the promoter of the IKKβ gene. The increase of IKKβ expression in ERβ-ablated cells correlates with an increase in phospho-IκBα and concomitant p65 nuclear translocation. An inverse correlation between the expression of ERβ and IKKβ/p65 was also observed in the prostates of ERβ knockout (BERKO) mice, Gleason grade 5 prostate tumors and analysis of prostate cancer databases. These findings provide a novel mechanism for how ERβ prevents NF-κB activation and raise the exciting possibility that loss of ERβ expression is linked to chronic inflammation in the prostate, which contributes to the development of high-grade prostate cancer. PMID:26450901

  2. Gustatory-mediated avoidance of bacterial lipopolysaccharides via TRPA1 activation in Drosophila

    Science.gov (United States)

    Soldano, Alessia; Alpizar, Yeranddy A; Boonen, Brett; Franco, Luis; López-Requena, Alejandro; Liu, Guangda; Mora, Natalia; Yaksi, Emre; Voets, Thomas; Vennekens, Rudi; Hassan, Bassem A; Talavera, Karel

    2016-01-01

    Detecting pathogens and mounting immune responses upon infection is crucial for animal health. However, these responses come at a high metabolic price (McKean and Lazzaro, 2011, Kominsky et al., 2010), and avoiding pathogens before infection may be advantageous. The bacterial endotoxins lipopolysaccharides (LPS) are important immune system infection cues (Abbas et al., 2014), but it remains unknown whether animals possess sensory mechanisms to detect them prior to infection. Here we show that Drosophila melanogaster display strong aversive responses to LPS and that gustatory neurons expressing Gr66a bitter receptors mediate avoidance of LPS in feeding and egg laying assays. We found the expression of the chemosensory cation channel dTRPA1 in these cells to be necessary and sufficient for LPS avoidance. Furthermore, LPS stimulates Drosophila neurons in a TRPA1-dependent manner and activates exogenous dTRPA1 channels in human cells. Our findings demonstrate that flies detect bacterial endotoxins via a gustatory pathway through TRPA1 activation as conserved molecular mechanism. DOI: http://dx.doi.org/10.7554/eLife.13133.001 PMID:27296646

  3. Ibrutinib interferes with the cell-mediated anti-tumor activities of therapeutic CD20 antibodies: implications for combination therapy

    DEFF Research Database (Denmark)

    Da Roit, F.; Engelberts, P. J.; Taylor, R. P.;

    2015-01-01

    The novel Bruton tyrosine kinase inhibitor ibrutinib and phosphatidyl-4-5-biphosphate 3-kinase-delta inhibitor idelalisib are promising drugs for the treatment of chronic lymphocytic leukemia and B-cell non-Hodgkin lymphoma, either alone or in combination with anti-CD20 antibodies. We investigated...... the possible positive or negative impact of these drugs on all known mechanisms of action of both type I and type II anti-CD20 antibodies. Pretreatment with ibrutinib for 1 hour did not increase direct cell death of cell lines or chronic lymphocytic leukemia samples mediated by anti-CD20 antibodies....... Pre-treatment with ibrutinib did not inhibit complement activation or complement-mediated lysis. In contrast, ibrutinib strongly inhibited all cell-mediated mechanisms induced by anti-CD20 antibodies rituximab, ofatumumab or obinutuzumab, either in purified systems or whole blood assays. Activation of...

  4. Toll-like receptor 4 mediates microglial activation and production of inflammatory mediators in neonatal rat brain following hypoxia: role of TLR4 in hypoxic microglia

    Directory of Open Access Journals (Sweden)

    Yao Linli

    2013-02-01

    Full Text Available Abstract Background Hypoxia induces microglial activation which causes damage to the developing brain. Microglia derived inflammatory mediators may contribute to this process. Toll-like receptor 4 (TLR4 has been reported to induce microglial activation and cytokines production in brain injuries; however, its role in hypoxic injury remains uncertain. We investigate here TLR4 expression and its roles in neuroinflammation in neonatal rats following hypoxic injury. Methods One day old Wistar rats were subjected to hypoxia for 2 h. Primary cultured microglia and BV-2 cells were subjected to hypoxia for different durations. TLR4 expression in microglia was determined by RT-PCR, western blot and immunofluorescence staining. Small interfering RNA (siRNA transfection and antibody neutralization were employed to downregulate TLR4 in BV-2 and primary culture. mRNA and protein expression of tumor necrosis factor-alpha (TNF-α, interleukin-1 beta (IL-1β and inducible nitric oxide synthase (iNOS was assessed. Reactive oxygen species (ROS, nitric oxide (NO and NF-κB levels were determined by flow cytometry, colorimetric and ELISA assays respectively. Hypoxia-inducible factor-1 alpha (HIF-1α mRNA and protein expression was quantified and where necessary, the protein expression was depleted by antibody neutralization. In vivo inhibition of TLR4 with CLI-095 injection was carried out followed by investigation of inflammatory mediators expression via double immunofluorescence staining. Results TLR4 immunofluorescence and protein expression in the corpus callosum and cerebellum in neonatal microglia were markedly enhanced post-hypoxia. In vitro, TLR4 protein expression was significantly increased in both primary microglia and BV-2 cells post-hypoxia. TLR4 neutralization in primary cultured microglia attenuated the hypoxia-induced expression of TNF-α, IL-1β and iNOS. siRNA knockdown of TLR4 reduced hypoxia-induced upregulation of TNF-α, IL-1β, iNOS, ROS and

  5. CAR-mediated repression of Foxo1 transcriptional activity regulates the cell cycle inhibitor p21 in mouse livers

    International Nuclear Information System (INIS)

    Highlights: • CAR activation decreased the level of Foxo1 in mouse livers. • CAR activation decreased the level of p21 in mouse livers. • CAR activation inhibited Foxo1 transcriptional activity in mouse livers. - Abstract: 1,4-Bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP), an agonist of constitutive androstane receptor (CAR), is a well-known strong primary chemical mitogen for the mouse liver. Despite extensive investigation of the role of CAR in the regulation of cell proliferation, our knowledge of the intricate mediating mechanism is incomplete. In this study, we demonstrated that long-term CAR activation by TCPOBOP increased liver-to-body weight ratio and decreased tumour suppressor Foxo1 expression and transcriptional activity, which were correlated with reduced expression of genes regulated by Foxo1, including the cell-cycle inhibitor Cdkn1a(p21), and upregulation of the cell-cycle regulator Cyclin D1. Moreover, we demonstrated the negative regulatory effect of TCPOBOP-activated CAR on the association of Foxo1 with the target Foxo1 itself and Cdkn1a(p21) promoters. Thus, we identified CAR-mediated repression of cell cycle inhibitor p21, as mediated by repression of FOXO1 expression and transcriptional activity. CAR-FOXO1 cross-talk may provide new opportunities for understanding liver diseases and developing more effective therapeutic approaches to better drug treatments

  6. A pH-mediated enhancement of the graphene carbocatalyst activity for the reduction of 4-nitrophenol.

    Science.gov (United States)

    Hu, Huawen; Wang, Xiaowen; Miao, Dagang; Wang, Yuanfeng; Lai, Chuilin; Guo, Yujuan; Wang, Wenyi; Xin, John H; Hu, Hong

    2015-12-01

    Using alkaline pH adjustment, the reaction between graphene oxide and L-ascorbic acid led to the formation of a carbocatalyst film with numerous graphene edges protruding out of basal planes, which had a markedly enhanced carbocatalytic activity for conversion of 4-nitrophenol to 4-aminophenol, as compared to that of the carbocatalyst counterpart without involving pH mediation. PMID:26434405

  7. p62 regulates CD40-mediated NFκB activation in macrophages through interaction with TRAF6

    Energy Technology Data Exchange (ETDEWEB)

    Seibold, Kristina; Ehrenschwender, Martin, E-mail: martin.ehrenschwender@ukr.de

    2015-08-14

    CD40 is a member of the tumor necrosis factor (TNF) receptor family. Activation-induced recruitment of adapter proteins, so-called TNF-receptor-associated factors (TRAFs) to the cytoplasmic tail of CD40 triggers signaling cascades important in the immune system, but has also been associated with excessive inflammation in diseases such as atherosclerosis and rheumatoid arthritis. Especially, pro-inflammatory nuclear factor κB (NFκB) signaling emanating from CD40-associated TRAF6 appears to be a key pathogenic driving force. Consequently, targeting the CD40-TRAF6 interaction is emerging as a promising therapeutic strategy, but the underlying molecular machinery of this signaling axis is to date poorly understood. Here, we identified the multifunctional adaptor protein p62 as a critical regulator in CD40-mediated NFκB signaling via TRAF6. CD40 activation triggered formation of a TRAF6-p62 complex. Disturbing this interaction tremendously reduced CD40-mediated NFκB signaling in macrophages, while TRAF6-independent signaling pathways remained unaffected. This highlights p62 as a potential target in hyper-inflammatory, CD40-associated pathologies. - Highlights: • CD40 activation triggers interaction of the adapter protein TRAF6 with p62. • TRAF6-p62 interaction regulates CD40-mediated NFκB signaling in macrophages. • Defective TRAF6-p62 interaction reduces CD40-mediated NFκB activation in macrophages.

  8. p62 regulates CD40-mediated NFκB activation in macrophages through interaction with TRAF6

    International Nuclear Information System (INIS)

    CD40 is a member of the tumor necrosis factor (TNF) receptor family. Activation-induced recruitment of adapter proteins, so-called TNF-receptor-associated factors (TRAFs) to the cytoplasmic tail of CD40 triggers signaling cascades important in the immune system, but has also been associated with excessive inflammation in diseases such as atherosclerosis and rheumatoid arthritis. Especially, pro-inflammatory nuclear factor κB (NFκB) signaling emanating from CD40-associated TRAF6 appears to be a key pathogenic driving force. Consequently, targeting the CD40-TRAF6 interaction is emerging as a promising therapeutic strategy, but the underlying molecular machinery of this signaling axis is to date poorly understood. Here, we identified the multifunctional adaptor protein p62 as a critical regulator in CD40-mediated NFκB signaling via TRAF6. CD40 activation triggered formation of a TRAF6-p62 complex. Disturbing this interaction tremendously reduced CD40-mediated NFκB signaling in macrophages, while TRAF6-independent signaling pathways remained unaffected. This highlights p62 as a potential target in hyper-inflammatory, CD40-associated pathologies. - Highlights: • CD40 activation triggers interaction of the adapter protein TRAF6 with p62. • TRAF6-p62 interaction regulates CD40-mediated NFκB signaling in macrophages. • Defective TRAF6-p62 interaction reduces CD40-mediated NFκB activation in macrophages

  9. Screen time, adiposity and cardiometabolic markers : mediation by physical activity, not snacking, among 11-year-old children

    NARCIS (Netherlands)

    Berentzen, N. E.; Smit, H. A.; van Rossem, L.; Gehring, U.; Kerkhof, M.; Postma, D. S.; Boshuizen, H. C.; Wijga, A. H.

    2014-01-01

    BACKGROUND: There is evidence for a relation of TV viewing with adiposity and increased cardiometabolic risk factors in children and adolescents. It is unclear to what extent this relation is mediated by snacking and lack of physical activity. We determined whether associations of screen time with a

  10. Screen time, adiposity and cardiometabolic markers: mediation by physical activity, not snacking, among 11-year-old children

    NARCIS (Netherlands)

    Berendtzen, N.E.; Smit, H.A.; Rossem, van L.; Gehring, U.; Kerkhof, van de M.; Postma, D.S.; Boshuizen, H.C.

    2014-01-01

    Background:There is evidence for a relation of TV viewing with adiposity and increased cardiometabolic risk factors in children and adolescents. It is unclear to what extent this relation is mediated by snacking and lack of physical activity. We determined whether associations of screen time with ad

  11. Does HPA-axis activity mediate the relationship between obstetric complications and externalizing behavior problems? The TRAILS study.

    NARCIS (Netherlands)

    Marsman, R.; Rosmalen, J.G.; Oldehinkel, A.J.; Ormel, J.; Buitelaar, J.K.

    2009-01-01

    To examine whether HPA-axis activity mediates the relationship between obstetric complications (OCs) and externalizing behavior problems, and to investigate whether this model is different for boys and girls. In a population-based cohort of 1,768 10- to 12-year-old early adolescents, we assessed the

  12. POLARIZED RELEASE OF LIPID MEDIATORS DERIVED FROM PHOSPHOLIPASE A2 ACTIVITY IN A HUMAN BRONCHIAL CELL LINE

    Science.gov (United States)

    The release of arachidonic acid (AA) and platelet activating factory (PAF) from airway epithelial cells may be an important mediating factor in lung physiological and inflammatory processes. The type of lung response may be determined by the directional release of AA and PAF. We ...

  13. Renin-angiotensin-aldosterone system blockade in chronic kidney disease: current strategies and a look ahead.

    Science.gov (United States)

    Viazzi, Francesca; Bonino, Barbara; Cappadona, Francesca; Pontremoli, Roberto

    2016-08-01

    The Renin-Angiotensin-Aldosterone System (RAAS) is profoundly involved in the pathogenesis of renal and cardiovascular organ damage, and has been the preferred therapeutic target for renal protection for over 30 years. Monotherapy with either an Angiotensin Converting Enzime Inhibitor (ACE-I) or an Angiotensin Receptor Blocker (ARB), together with optimal blood pressure control, remains the mainstay treatment for retarding the progression toward end-stage renal disease. Combining ACE-Is and ARBs, or either one with an Aldosterone Receptor Antagonist (ARA), has been shown to provide greater albuminuria reduction, and to possibly improve renal outcome, but at an increased risk of potentially severe side effects. Moreover, combination therapy has failed to provide additional cardiovascular protection, and large prospective trials on hard renal endpoints are lacking. Therefore this treatment should, at present, be limited to selected patients with residual proteinuria and high renal risk. Future studies with novel agents, which directly act on the RAAS at multiple levels or have a more favourable side effect profile, are greatly needed to further explore and define the potential for and the limitations of profound pharmacologic RAAS inhibition. PMID:26984204

  14. Aldosterone-secreting adrenal cortical carcinoma. A case report and review of the literature.

    Science.gov (United States)

    Griffin, Adrienne Carruth; Kelz, Rachel; LiVolsi, Virginia A

    2014-09-01

    Adrenal cortical carcinomas (ACC) are rare, typically aggressive malignant neoplasms with a reported incidence of 1-2 cases per 1 million population and account for 0.05-0.2 % of all malignancies. The majority of these tumors are functional with approximately 60 % of patients experiencing endocrine symptomatology typically characterized by Cushing's syndrome (40 %) or a mixed hormonal picture of Cushing syndrome seen in association with virilization. Rarely, patients present with a pure hormonal syndrome of feminization or hyperaldosteronism, 6 and 2.5 %, respectively. We report a case of a 76-year-old woman presenting with recently diagnosed hypertension secondary to primary hyperaldosteronism. The patient underwent laparoscopic converted to an open adrenalectomy and a diagnosis of adrenocortical carcinoma (aldosteronoma clinical) was rendered. This case and review of the literature highlight that while rare, aldosterone-secreting adrenal cortical carcinomas may occur. In this case report, we discuss the clinical presentation, pathologic findings, and review the literature for adrenal cortical carcinomas and aldosterone-secreting adrenal cortical carcinomas. PMID:24682757

  15. HEAT-INDUCED CHANGES IN ALDOSTERONE LEVEL AND MINERAL BALANCE IN EGYPTIAN BUFFALO CALVES

    International Nuclear Information System (INIS)

    Eight male buffalo calves (13 months old) were used in the present study. The animals were maintained in metabolic cages inside a climatic chamber for 2 weeks under mild climate at 210C and 73% RH for 6 hours daily as an adjustment period followed by 7 days at the same climatic conditions as a control period then followed by a heat exposure period for 7 days at 35-420C and 40-50 % RH for 6 hours daily. The animals were fed individually on concentrates and wheat straw. Plasma aldosterone was estimated on the first day after 6 hours of each mild and hot exposure periods. Sodium, potassium, calcium, phosphorus and magnesium balances were estimated on the last three days of control and heat exposure periods. Rectal temperature and respiration rate were recorded daily during both periods. The rectal temperature was raised (P0C by the end of 6 hours heat exposure period. The respiration rate was increased (P<0.01) at the end of 6 hours of heat exposure from 25 to 110.81 breaths/minute. Aldosterone was increased (P<0.05) from 5.79 to 37.11 pg/ml whereas sodium, potassium, calcium, phosphorus and magnesium were decreased (P<0.01) by 19.16 %, 40.70%, 46.05 %, 35.69 % and 48.99%, respectively.

  16. Valerian inhibits rat hepatocarcinogenesis by activating GABA(A receptor-mediated signaling.

    Directory of Open Access Journals (Sweden)

    Anna Kakehashi

    Full Text Available Valerian is widely used as a traditional medicine to improve the quality of sleep due to interaction of several active components with the γ-aminobutyric acid (GABA A receptor (GABA(AR system. Recently, activation of GABA signaling in stem cells has been reported to suppress cell cycle progression in vivo. Furthermore, possible inhibitory effects of GABA(AR agonists on hepatocarcinogenesis have been reported. The present study was performed to investigate modulating effects of Valerian on hepatocarcinogenesis using a medium-term rat liver bioassay. Male F344 rats were treated with one of the most powerful Valerian species (Valeriana sitchensis at doses of 0, 50, 500 and 5000 ppm in their drinking water after initiation of hepatocarcinogenesis with diethylnitrosamine (DEN. Formation of glutathione S-transferase placental form positive (GST-P(+ foci was significantly inhibited by Valerian at all applied doses compared with DEN initiation control rats. Generation of 8-hydroxy-2'-deoxyguanosine in the rat liver was significantly suppressed by all doses of Valerian, likely due to suppression of Nrf2, CYP7A1 and induction of catalase expression. Cell proliferation was significantly inhibited, while apoptosis was induced in areas of GST-P(+ foci of Valerian groups associated with suppression of c-myc, Mafb, cyclin D1 and induction of p21(Waf1/Cip1, p53 and Bax mRNA expression. Interestingly, expression of the GABA(AR alpha 1 subunit was observed in GST-P(+ foci of DEN control rats, with significant elevation associated with Valerian treatment. These results indicate that Valerian exhibits inhibitory effects on rat hepatocarcinogenesis by inhibiting oxidative DNA damage, suppressing cell proliferation and inducing apoptosis in GST-P(+ foci by activating GABA(AR-mediated signaling.

  17. Valerian inhibits rat hepatocarcinogenesis by activating GABA(A) receptor-mediated signaling.

    Science.gov (United States)

    Kakehashi, Anna; Kato, Ayumi; Ishii, Naomi; Wei, Min; Morimura, Keiichirou; Fukushima, Shoji; Wanibuchi, Hideki

    2014-01-01

    Valerian is widely used as a traditional medicine to improve the quality of sleep due to interaction of several active components with the γ-aminobutyric acid (GABA) A receptor (GABA(A)R) system. Recently, activation of GABA signaling in stem cells has been reported to suppress cell cycle progression in vivo. Furthermore, possible inhibitory effects of GABA(A)R agonists on hepatocarcinogenesis have been reported. The present study was performed to investigate modulating effects of Valerian on hepatocarcinogenesis using a medium-term rat liver bioassay. Male F344 rats were treated with one of the most powerful Valerian species (Valeriana sitchensis) at doses of 0, 50, 500 and 5000 ppm in their drinking water after initiation of hepatocarcinogenesis with diethylnitrosamine (DEN). Formation of glutathione S-transferase placental form positive (GST-P(+)) foci was significantly inhibited by Valerian at all applied doses compared with DEN initiation control rats. Generation of 8-hydroxy-2'-deoxyguanosine in the rat liver was significantly suppressed by all doses of Valerian, likely due to suppression of Nrf2, CYP7A1 and induction of catalase expression. Cell proliferation was significantly inhibited, while apoptosis was induced in areas of GST-P(+) foci of Valerian groups associated with suppression of c-myc, Mafb, cyclin D1 and induction of p21(Waf1/Cip1), p53 and Bax mRNA expression. Interestingly, expression of the GABA(A)R alpha 1 subunit was observed in GST-P(+) foci of DEN control rats, with significant elevation associated with Valerian treatment. These results indicate that Valerian exhibits inhibitory effects on rat hepatocarcinogenesis by inhibiting oxidative DNA damage, suppressing cell proliferation and inducing apoptosis in GST-P(+) foci by activating GABA(A)R-mediated signaling. PMID:25419570

  18. AAV-mediated delivery of zinc finger nucleases targeting hepatitis B virus inhibits active replication.

    Directory of Open Access Journals (Sweden)

    Nicholas D Weber

    Full Text Available Despite an existing effective vaccine, hepatitis B virus (HBV remains a major public health concern. There are effective suppressive therapies for HBV, but they remain expensive and inaccessible to many, and not all patients respond well. Furthermore, HBV can persist as genomic covalently closed circular DNA (cccDNA that remains in hepatocytes even during otherwise effective therapy and facilitates rebound in patients after treatment has stopped. Therefore, the need for an effective treatment that targets active and persistent HBV infections remains. As a novel approach to treat HBV, we have targeted the HBV genome for disruption to prevent viral reactivation and replication. We generated 3 zinc finger nucleases (ZFNs that target sequences within the HBV polymerase, core and X genes. Upon the formation of ZFN-induced DNA double strand breaks (DSB, imprecise repair by non-homologous end joining leads to mutations that inactivate HBV genes. We delivered HBV-specific ZFNs using self-complementary adeno-associated virus (scAAV vectors and tested their anti-HBV activity in HepAD38 cells. HBV-ZFNs efficiently disrupted HBV target sites by inducing site-specific mutations. Cytotoxicity was seen with one of the ZFNs. scAAV-mediated delivery of a ZFN targeting HBV polymerase resulted in complete inhibition of HBV DNA replication and production of infectious HBV virions in HepAD38 cells. This effect was sustained for at least 2 weeks following only a single treatment. Furthermore, high specificity was observed for all ZFNs, as negligible off-target cleavage was seen via high-throughput sequencing of 7 closely matched potential off-target sites. These results show that HBV-targeted ZFNs can efficiently inhibit active HBV replication and suppress the cellular template for HBV persistence, making them promising candidates for eradication therapy.

  19. AAV-mediated delivery of zinc finger nucleases targeting hepatitis B virus inhibits active replication.

    Science.gov (United States)

    Weber, Nicholas D; Stone, Daniel; Sedlak, Ruth Hall; De Silva Feelixge, Harshana S; Roychoudhury, Pavitra; Schiffer, Joshua T; Aubert, Martine; Jerome, Keith R

    2014-01-01

    Despite an existing effective vaccine, hepatitis B virus (HBV) remains a major public health concern. There are effective suppressive therapies for HBV, but they remain expensive and inaccessible to many, and not all patients respond well. Furthermore, HBV can persist as genomic covalently closed circular DNA (cccDNA) that remains in hepatocytes even during otherwise effective therapy and facilitates rebound in patients after treatment has stopped. Therefore, the need for an effective treatment that targets active and persistent HBV infections remains. As a novel approach to treat HBV, we have targeted the HBV genome for disruption to prevent viral reactivation and replication. We generated 3 zinc finger nucleases (ZFNs) that target sequences within the HBV polymerase, core and X genes. Upon the formation of ZFN-induced DNA double strand breaks (DSB), imprecise repair by non-homologous end joining leads to mutations that inactivate HBV genes. We delivered HBV-specific ZFNs using self-complementary adeno-associated virus (scAAV) vectors and tested their anti-HBV activity in HepAD38 cells. HBV-ZFNs efficiently disrupted HBV target sites by inducing site-specific mutations. Cytotoxicity was seen with one of the ZFNs. scAAV-mediated delivery of a ZFN targeting HBV polymerase resulted in complete inhibition of HBV DNA replication and production of infectious HBV virions in HepAD38 cells. This effect was sustained for at least 2 weeks following only a single treatment. Furthermore, high specificity was observed for all ZFNs, as negligible off-target cleavage was seen via high-throughput sequencing of 7 closely matched potential off-target sites. These results show that HBV-targeted ZFNs can efficiently inhibit active HBV replication and suppress the cellular template for HBV persistence, making them promising candidates for eradication therapy. PMID:24827459

  20. A test of cognitive mediation in a 12-month physical activity workplace intervention: does it explain behaviour change in women?

    Directory of Open Access Journals (Sweden)

    Pickering Michael A

    2010-05-01

    Full Text Available Abstract Background Attempts to demonstrate the efficacy of interventions aimed at increasing physical activity (PA have been mixed. Further, studies are seldom designed in a manner that facilitates the understanding of how or why a treatment is effective or ineffective and PA intervention designs should be guided by a heavier reliance upon behavioral theory. The use of a mediating variable framework offers a systematic methodological approach to testing the role of theory, and could also identify the effectiveness of specific intervention components. The primary purpose of this paper was to test the mediating role that cognitive constructs may have played in regards to the positive effect that a workplace behavioral intervention had on leisure-time PA for women. A subsidiary purpose was to examine the cross-sectional relationships of these cognitive constructs with PA behavior. Methods The Physical Activity Workplace Study was a randomized controlled trial which compared the effects of stage-matched and standard print materials upon self-reported leisure-time PA, within a workplace sample at 6 and 12-months. In this secondary analysis we examined the mediation effects of 14 psychosocial constructs across 3 major social-cognitive theories which were operationalized for the intervention materials and measured at baseline, 6 and 12-months. We examined change in PA and change in the psychological constructs employing a mediation strategy proposed by Baron and Kenny for: (1 the first 6-months (i.e., initial change, (2 the second 6-months (i.e., delayed change, and (3 the entire 12-months (overall change of the study on 323 women (n = 213 control/standard materials group; n = 110 stage-matched materials group. Results Of the 14 constructs and 42 tests (including initial, delayed and overall change two positive results were identified (i.e., overall change in pros, initial change in experiential powerful intervention approaches processes, with very

  1. Adenoviral augmentation of elafin protects the lung against acute injury mediated by activated neutrophils and bacterial infection.

    Science.gov (United States)

    Simpson, A J; Wallace, W A; Marsden, M E; Govan, J R; Porteous, D J; Haslett, C; Sallenave, J M

    2001-08-01

    During acute pulmonary infection, tissue injury may be secondary to the effects of bacterial products or to the effects of the host inflammatory response. An attractive strategy for tissue protection in this setting would combine antimicrobial activity with inhibition of human neutrophil elastase (HNE), a key effector of neutrophil-mediated tissue injury. We postulated that genetic augmentation of elafin (an endogenous inhibitor of HNE with intrinsic antimicrobial activity) could protect the lung against acute inflammatory injury without detriment to host defense. A replication-deficient adenovirus encoding elafin cDNA significantly protected A549 cells against the injurious effects of both HNE and whole activated human neutrophils in vitro. Intratracheal replication-deficient adenovirus encoding elafin cDNA significantly protected murine lungs against injury mediated by Pseudomonas aeruginosa in vivo. Genetic augmentation of elafin therefore has the capacity to protect the lung against the injurious effects of both bacterial pathogens resistant to conventional antibiotics and activated neutrophils. PMID:11466403

  2. Neutralization of lymphokine-mediated antirickettsial activity of fibroblasts and macrophages with monoclonal antibody specific for murine interferon gamma.

    OpenAIRE

    Jerrells, T R; Turco, J; Winkler, H H; Spitalny, G L

    1986-01-01

    Lymphokine-mediated inhibition of Rickettsia prowazekii multiplication in L929 fibroblasts was eliminated by treatment of the lymphokine with a monoclonal antibody specific for interferon-gamma. Soluble monoclonal antibody and antibody conjugated to Sepharose beads were equally effective. Macrophage activation to limit the multiplication of Rickettsia conorii was eliminated with antibody-conjugated beads; however, neutralization of the ability to activate macrophages with soluble antibody was...

  3. Thioredoxin is involved in endothelial cell extracellular transglutaminase 2 activation mediated by celiac disease patient IgA.

    Directory of Open Access Journals (Sweden)

    Cristina Antonella Nadalutti

    Full Text Available PURPOSE: To investigate the role of thioredoxin (TRX, a novel regulator of extracellular transglutaminase 2 (TG2, in celiac patients IgA (CD IgA mediated TG2 enzymatic activation. METHODS: TG2 enzymatic activity was evaluated in endothelial cells (HUVECs under different experimental conditions by ELISA and Western blotting. Extracellular TG2 expression was studied by ELISA and immunofluorescence. TRX was analysed by Western blotting and ELISA. Serum immunoglobulins class A from healthy subjects (H IgA were used as controls. Extracellular TG2 enzymatic activity was inhibited by R281. PX12, a TRX inhibitor, was also employed in the present study. RESULTS: We have found that in HUVECs CD IgA is able to induce the activation of extracellular TG2 in a dose-dependent manner. Particularly, we noted that the extracellular modulation of TG2 activity mediated by CD IgA occurred only under reducing conditions, also needed to maintain antibody binding. Furthermore, CD IgA-treated HUVECs were characterized by a slightly augmented TG2 surface expression which was independent from extracellular TG2 activation. We also observed that HUVECs cultured in the presence of CD IgA evinced decreased TRX surface expression, coupled with increased secretion of the protein into the culture medium. Intriguingly, inhibition of TRX after CD IgA treatment was able to overcome most of the CD IgA-mediated effects including the TG2 extracellular transamidase activity. CONCLUSIONS: Altogether our findings suggest that in endothelial cells CD IgA mediate the constitutive activation of extracellular TG2 by a mechanism involving the redox sensor protein TRX.

  4. Suppression by Apoptotic Cells Defines Tumor Necrosis Factor-Mediated Induction of Glomerular Mesangial Cell Apoptosis by Activated Macrophages

    OpenAIRE

    Duffield, Jeremy S.; Ware, Carl F.; Ryffel, Bernhardt; Savill, John

    2001-01-01

    Activated macrophages (Mφ) isolated from inflamed glomeruli or generated by interferon-γ and lipopolysaccharide treatment in vitro induce glomerular mesangial cell apoptosis by hitherto incompletely understood mechanisms. In this report we demonstrate that nitric oxide-independent killing of co-cultured mesangial cells by interferon-γ/lipopolysaccharide-activated Mφ is suppressed by binding/ingestion of apoptotic cells and is mediated by tumor necrosis factor (TNF). Thus, soluble TNF receptor...

  5. Sox17 modulates Wnt3A/β-catenin-mediated transcriptional activation of the Lef-1 promoter

    OpenAIRE

    Liu, Xiaoming; Luo, Meihui; Xie, Weiliang; Wells, James M.; Goodheart, Michael J.; Engelhardt, John F

    2010-01-01

    Wnt/β-catenin-dependent activation of lymphoid enhancer factor 1 (Lef-1) plays an important role in numerous developmental processes. In this context, transcription of the Lef-1 gene is increased by Wnt-mediated TCF4/β-catenin activation on the Lef-1 promoter through mechanisms that remain poorly defined. In mouse airway submucosal gland progenitor cells, Wnt3A transiently induces Lef-1 gene expression, and this process is required for epithelial cell proliferation and glandular morphogenesis...

  6. BRCA1 loss activates cathepsin L–mediated degradation of 53BP1 in breast cancer cells

    OpenAIRE

    Grotsky, David A.; González-Suárez, Ignacio; Novell Álvarez, Anna; Neumann, Martin; Yaddanapudi, Sree C.; Croke, Monica; Martínez Alonso, Montserrat; Redwood, Abena B.; Ortega-Martinez, Sylvia; Feng, Zhihui; Lerma, Enrique; Ramon y Cajal, Teresa; Zhang, Junran; Matias-Guiu, Xavier; Dusso, Adriana

    2013-01-01

    Loss of 53BP1 rescues BRCA1 deficiency and is associated with BRCA1-deficient and triple-negative breast cancers (TNBC) and with resistance to genotoxic drugs. The mechanisms responsible for decreased 53BP1 transcript and protein levels in tumors remain unknown. Here, we demonstrate that BRCA1 loss activates cathepsin L (CTSL)–mediated degradation of 53BP1. Activation of this pathway rescued homologous recombination repair and allowed BRCA1-deficient cells to bypass growth arrest. Importantly...

  7. Associations between children's social functioning and physical activity participation are not mediated by social acceptance: a cross-sectional study

    OpenAIRE

    Brockman Rowan; Page Angie S; Fox Kenneth R; Jago Russell; Sebire Simon J; Thompson Janice L

    2011-01-01

    Abstract Background Physical activity (PA) during childhood often occurs in social contexts. As such, children's ability to develop and maintain friendship groups may be important in understanding their PA. This paper investigates the associations among children's social functioning, and physical activity and whether perceptions of social acceptance mediate any social functioning-PA association. Methods A cross sectional survey in which 652 10-11 year olds self-reported their peer (e.g. diffi...

  8. Electrochemical monitoring of intracellular enzyme activity of single living mammalian cells by using a double-mediator system

    International Nuclear Information System (INIS)

    Graphical abstract: NAD(P)H:quinone oxidoreductase (NQO) activity of single HeLa cells were evaluated by using the menadione–ferrocyanide double mediator system combined with scanning electrochemical microscopy (SECM). - Highlights: • NAD(P)H:quinone oxidoreductase activity of single cells were evaluated with SECM. • Fe(CN)63−/menadione concentrations were optimized for long-term SECM monitoring. • Menadione affect the intracellular levels of reactive oxygen species and GSH. • At 100 μM menadione, the Fe(CN)63− generation rate decreased rapidly within 30 min. - Abstract: We evaluated the intracellular NAD(P)H:quinone oxidoreductase (NQO) activity of single HeLa cells by using the menadione–ferrocyanide double-mediator system combined with scanning electrochemical microscopy (SECM). The double-mediator system was used to amplify the current response from the intracellular NQO activity and to reduce menadione-induced cell damage. The electron shuttle between the electrode and menadione was mediated by the ferrocyanide/ferricyanide redox couple. Generation of ferrocyanide was observed immediately after the addition of a lower concentration (10 μM) of menadione. The ferrocyanide generation rate was constant for 120 min. At a higher menadione concentration (100 μM), the ferrocyanide generation rate decreased within 30 min because of the cytotoxic effect of menadione. We also investigated the relationship between intracellular reactive oxygen species or glutathione levels and exposure to different menadione concentrations to determine the optimal condition for SECM with minimal invasiveness. The present study clearly demonstrates that SECM is useful for the analysis of intracellular enzymatic activities in single cells with a double-mediator system

  9. Electrochemical monitoring of intracellular enzyme activity of single living mammalian cells by using a double-mediator system

    Energy Technology Data Exchange (ETDEWEB)

    Matsumae, Yoshiharu [Graduate School of Environmental Studies, Tohoku University, Aramaki 6-6-11-605, Aoba, Sendai 980-8579 (Japan); Takahashi, Yasufumi [Advanced Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba, Sendai 980-8577 (Japan); Ino, Kosuke [Graduate School of Environmental Studies, Tohoku University, Aramaki 6-6-11-605, Aoba, Sendai 980-8579 (Japan); Shiku, Hitoshi, E-mail: shiku@bioinfo.che.tohoku.ac.jp [Graduate School of Environmental Studies, Tohoku University, Aramaki 6-6-11-605, Aoba, Sendai 980-8579 (Japan); Matsue, Tomokazu, E-mail: matsue@bioinfo.che.tohoku.ac.jp [Graduate School of Environmental Studies, Tohoku University, Aramaki 6-6-11-605, Aoba, Sendai 980-8579 (Japan); Advanced Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba, Sendai 980-8577 (Japan)

    2014-09-09

    Graphical abstract: NAD(P)H:quinone oxidoreductase (NQO) activity of single HeLa cells were evaluated by using the menadione–ferrocyanide double mediator system combined with scanning electrochemical microscopy (SECM). - Highlights: • NAD(P)H:quinone oxidoreductase activity of single cells were evaluated with SECM. • Fe(CN){sub 6}{sup 3−}/menadione concentrations were optimized for long-term SECM monitoring. • Menadione affect the intracellular levels of reactive oxygen species and GSH. • At 100 μM menadione, the Fe(CN){sub 6}{sup 3−} generation rate decreased rapidly within 30 min. - Abstract: We evaluated the intracellular NAD(P)H:quinone oxidoreductase (NQO) activity of single HeLa cells by using the menadione–ferrocyanide double-mediator system combined with scanning electrochemical microscopy (SECM). The double-mediator system was used to amplify the current response from the intracellular NQO activity and to reduce menadione-induced cell damage. The electron shuttle between the electrode and menadione was mediated by the ferrocyanide/ferricyanide redox couple. Generation of ferrocyanide was observed immediately after the addition of a lower concentration (10 μM) of menadione. The ferrocyanide generation rate was constant for 120 min. At a higher menadione concentration (100 μM), the ferrocyanide generation rate decreased within 30 min because of the cytotoxic effect of menadione. We also investigated the relationship between intracellular reactive oxygen species or glutathione levels and exposure to different menadione concentrations to determine the optimal condition for SECM with minimal invasiveness. The present study clearly demonstrates that SECM is useful for the analysis of intracellular enzymatic activities in single cells with a double-mediator system.

  10. Acutely elevated vasopressin increases circulating concentrations of cortisol and aldosterone in fasting northern elephant seal (Mirounga angustirostris) pups

    Science.gov (United States)

    Ortiz, Rudy M.; Wade, Charles E.; Ortiz, C. Leo; Talamantes, Frank

    2003-01-01

    The physiological actions of vasopressin (VP) in marine mammals are not well defined. To help elucidate its hormonal and renal effects in this group of mammals, northern elephant seal (Mirounga angustirostris) pups (N=7; 99+/-4 kg) were first infused with 0.9% saline (control; 220 ml), followed 24 h later with VP (as a 20 ng kg(-1) bolus, then 2 ng kg(-1) min(-1) for approximately 35 min in 225+/-16 ml saline). During both control and VP periods, blood samples were collected prior to infusion, and 15, 30, 60, 120 min and 24 h after infusion to examine the hormonal responses of the pups to VP. Renal responses were quantified from 24 h urine samples obtained prior to infusion (control) and 24 h post-infusion. Compared to the control period, infusion of VP increased plasma concentrations of cortisol over a 120 min period and aldosterone over 30 min, while plasma renin activity (PRA) was decreased for a 120 min period. The plasma urea:creatinine ratio was elevated following infusion of VP. Urine output and osmotic clearance were increased by 69+/-18% (mean +/- S.E.M.) and 36+/-10%, respectively, but free water clearance and glomerular filtration rate were not significantly altered 24 h post-infusion of VP. Solute (osmolality, Na(+), K(+) and Cl(-)) excretion and fractional excretion of electrolytes were also increased when compared to control values. The increase in cortisol concentration suggests that VP may possess corticotropin releasing hormone-like activity in elephant seals. If osmotic diuresis and natriuresis are typical consequences of elevated [VP] in fasting pups, then not increasing VP normally during the fast may serve as a protective mechanism to avoid the potential loss of Na(+) induced by elevated [VP]. Therefore, under natural fasting conditions, pups may be highly sensitive to small changes in [VP], resulting in the maintenance of water and electrolyte balance.

  11. A detailed physiologically-based model to simulate the pharmacokinetics and hormonal pharmacodynamics of enalapril on the circulating endocrine renin-angiotensin-aldosterone system

    Directory of Open Access Journals (Sweden)

    MichaelBlock

    2013-02-01

    Full Text Available The renin-angiotensin-aldosterone system (RAAS plays a key role in the pathogenesis of cardiovascular disorders including hypertension and is one of the most important targets for drugs. A whole body physiologically-based pharmacokinetic (wb PBPK model integrating this hormone circulation system and its inhibition can be used to explore the influence of drugs that interfere with this system, and thus to improve the understanding of interactions between drugs and the target system. In this study, we describe the development of a mechanistic RAAS model and exemplify drug action by a simulation of enalapril administration. Enalapril and its metabolite enalaprilat are potent inhibitors of the angiotensin-converting enzyme (ACE. To this end, a coupled dynamic parent-metabolite PBPK model was developed and linked with the RAAS model that consists of seven coupled PBPK models for aldosterone, ACE , angiotensin 1, angiotensin 2, angiotensin 2 receptor type 1, renin and prorenin. The results indicate that the model represents the interactions in the RAAS in response to the pharmacokinetics (PK and pharmacodynamics (PD of enalapril and enalaprilat in an accurate manner. The full set of RAAS hormone profiles and interactions are consistently described at pre- and post-administration steady state as well as during their dynamic transition and show a good agreement to literature data. The model allows a simultaneous representation of the parent-metabolite conversion to the active form as well as the effect of the drug on the hormone levels, offering a detailed mechanistic insight into the hormone cascade and its inhibition. This model constitutes a first major step to establish a PBPK-PD model including the PK and the mode of action (MoA of a drug acting on a dynamic RAAS that can be further used to link to clinical endpoints such as blood pressure.

  12. Concurrent inhibition of kit- and FcepsilonRI-mediated signaling: coordinated suppression of mast cell activation

    DEFF Research Database (Denmark)

    Jensen, Bettina M; Beaven, Michael A; Iwaki, Shoko;

    2008-01-01

    characterized Kit inhibitor imatinib mesylate (imatinib). In contrast to imatinib, however, hypothemycin also effectively inhibited FcepsilonRI-mediated degranulation and cytokine production in addition to the potentiation of these responses via Kit. The effect of hypothemycin on Kit-mediated responses could...

  13. Activated Carbon as an Electron Acceptor and Redox Mediator during the Anaerobic Biotransformation of Azo Dyes

    NARCIS (Netherlands)

    Zee, van der F.P.; Bisschops, I.A.E.; Lettinga, G.; Field, J.A.

    2003-01-01

    The role of AC as redox mediator in accelerating the reductive transformation of pollutants as well as a terminal electron acceptor in the biological oxidation of an organic substrate is described. This study explores the use of AC as an immobilized redox mediator for the reduction of a recalcitrant

  14. N6-isopentenyladenosine and analogs activate the NRF2-mediated antioxidant response

    Directory of Open Access Journals (Sweden)

    Alice Dassano

    2014-01-01

    Full Text Available N6-isopentenyladenosine (i6A, a naturally occurring modified nucleoside, inhibits the proliferation of human tumor cell lines in vitro, but its mechanism of action remains unclear. Treatment of MCF7 human breast adenocarcinoma cells with i6A or with three synthetic analogs (allyl6A, benzyl6A, and butyl6A inhibited growth and altered gene expression. About 60% of the genes that were differentially expressed in response to i6A treatment were also modulated by the analogs, and pathway enrichment analysis identified the NRF2-mediated oxidative stress response as being significantly modulated by all four compounds. Luciferase reporter gene assays in transfected MCF7 cells confirmed that i6A activates the transcription factor NRF2. Assays for cellular production of reactive oxygen species indicated that i6A and analogs had antioxidant effects, reducing basal levels and inhibiting the H2O2- or 12-O-tetradecanoylphorbol-13-acetate (TPA-induced production in MCF7 or dHL-60 (HL-60 cells induced to differentiate along the neutrophilic lineage cell lines, respectively. In vivo, topical application of i6A or benzyl6A to mouse ears prior to TPA stimulation lessened the inflammatory response and significantly reduced the number of infiltrating neutrophils. These results suggest that i6A and analogs trigger a cellular response against oxidative stress and open the possibility of i6A and benzyl6A being used as topical anti-inflammatory drugs.

  15. Serum Response Factor (SRF mediated gene activity in physiological and pathological processes of neuronal motility

    Directory of Open Access Journals (Sweden)

    Bernd Knoll

    2011-12-01

    Full Text Available In recent years, the transcription factor SRF (serum response factor was shown to contribute to various physiological processes linked to neuronal motility. The latter include cell migration, axon guidance and e.g. synapse function relying on cytoskeletal dynamics, neurite outgrowth, axonal and dendritic differentiation, growth cone motility and neurite branching. SRF teams up with MRTFs (myocardin related transcription factors and TCFs (ternary complex factors to mediate cellular actin cytoskeletal dynamics and the immediate-early gene (IEG response, a bona fide indicator of neuronal activation. Herein, I will discuss how SRF and cofactors might modulate physiological processes of neuronal motility. Further, potential mechanisms engaged by neurite growth promoting molecules and axon guidance cues to target SRF’s transcriptional machinery in physiological neuronal motility will be presented. Of note, altered cytoskeletal dynamics and rapid initiation of an IEG response are a hallmark of injured neurons in various neurological disorders. Thus, SRF and its MRTF and TCF cofactors might emerge as a novel trio modulating peripheral and central axon regeneration.

  16. 5-Azacytidine Promotes an Inhibitory T-Cell Phenotype and Impairs Immune Mediated Antileukemic Activity

    Directory of Open Access Journals (Sweden)

    Thomas Stübig

    2014-01-01

    Full Text Available Demethylating agent, 5-Azacytidine (5-Aza, has been shown to be active in treatment of myeloid malignancies. 5-Aza enhances anticancer immunity, by increasing expression of tumor-associated antigens. However, the impact of 5-Aza immune responses remains poorly understood. Here, T-cell mediated tumor immunity effects of 5-Aza, are investigated in vitro and in vivo. T-cells from healthy donors were treated with 5-Aza and analyzed by qRT-PCR and flow cytometry for changes in gene expression and phenotype. Functionality was assessed by a tumor lysis assay. Peripheral blood from patients treated with 5-Aza after alloSCT was monitored for changes in T-cell subpopulations. 5-Aza treatment resulted in a decrease in CD8+ T-cells, whereas CD4+ T-cells increased. Furthermore, numbers of IFN-γ+ T-helper 1 cells (Th1 were reduced, while Treg-cells showed substantial increase. Additionally, CD8+ T-cells exhibited limited killing capacity against leukemic target cells. In vivo data confirm the increase of Treg compartment, while CD8+ T-effector cell numbers were reduced. 5-Aza treatment results in a shift from cytotoxic to regulatory T-cells with a functional phenotype and a major reduction in proinflammatory Th1-cells, indicating a strong inhibition of tumor-specific T-cell immunity by 5-Aza.

  17. 5-Azacytidine Promotes an Inhibitory T-Cell Phenotype and Impairs Immune Mediated Antileukemic Activity

    Science.gov (United States)

    Stübig, Thomas; Luetkens, Tim; Hildebrandt, York; Atanackovic, Djordje; Binder, Thomas M. C.; Fehse, Boris; Kröger, Nicolaus

    2014-01-01

    Demethylating agent, 5-Azacytidine (5-Aza), has been shown to be active in treatment of myeloid malignancies. 5-Aza enhances anticancer immunity, by increasing expression of tumor-associated antigens. However, the impact of 5-Aza immune responses remains poorly understood. Here, T-cell mediated tumor immunity effects of 5-Aza, are investigated in vitro and in vivo. T-cells from healthy donors were treated with 5-Aza and analyzed by qRT-PCR and flow cytometry for changes in gene expression and phenotype. Functionality was assessed by a tumor lysis assay. Peripheral blood from patients treated with 5-Aza after alloSCT was monitored for changes in T-cell subpopulations. 5-Aza treatment resulted in a decrease in CD8+ T-cells, whereas CD4+ T-cells increased. Furthermore, numbers of IFN-γ+ T-helper 1 cells (Th1) were reduced, while Treg-cells showed substantial increase. Additionally, CD8+ T-cells exhibited limited killing capacity against leukemic target cells. In vivo data confirm the increase of Treg compartment, while CD8+ T-effector cell numbers were reduced. 5-Aza treatment results in a shift from cytotoxic to regulatory T-cells with a functional phenotype and a major reduction in proinflammatory Th1-cells, indicating a strong inhibition of tumor-specific T-cell immunity by 5-Aza. PMID:24757283

  18. 5-azacytidine promotes an inhibitory T-cell phenotype and impairs immune mediated antileukemic activity.

    Science.gov (United States)

    Stübig, Thomas; Badbaran, Anita; Luetkens, Tim; Hildebrandt, York; Atanackovic, Djordje; Binder, Thomas M C; Fehse, Boris; Kröger, Nicolaus

    2014-01-01

    Demethylating agent, 5-Azacytidine (5-Aza), has been shown to be active in treatment of myeloid malignancies. 5-Aza enhances anticancer immunity, by increasing expression of tumor-associated antigens. However, the impact of 5-Aza immune responses remains poorly understood. Here, T-cell mediated tumor immunity effects of 5-Aza, are investigated in vitro and in vivo. T-cells from healthy donors were treated with 5-Aza and analyzed by qRT-PCR and flow cytometry for changes in gene expression and phenotype. Functionality was assessed by a tumor lysis assay. Peripheral blood from patients treated with 5-Aza after alloSCT was monitored for changes in T-cell subpopulations. 5-Aza treatment resulted in a decrease in CD8+ T-cells, whereas CD4+ T-cells increased. Furthermore, numbers of IFN-γ + T-helper 1 cells (Th1) were reduced, while Treg-cells showed substantial increase. Additionally, CD8+ T-cells exhibited limited killing capacity against leukemic target cells. In vivo data confirm the increase of Treg compartment, while CD8+ T-effector cell numbers were reduced. 5-Aza treatment results in a shift from cytotoxic to regulatory T-cells with a functional phenotype and a major reduction in proinflammatory Th1-cells, indicating a strong inhibition of tumor-specific T-cell immunity by 5-Aza. PMID:24757283

  19. Multiple Rad5 activities mediate sister chromatid recombination to bypass DNA damage at stalled replication forks.

    Science.gov (United States)

    Minca, Eugen C; Kowalski, David

    2010-06-11

    DNA damage that blocks replication is bypassed in order to complete chromosome duplication and preserve cell viability and genome stability. Rad5, a PCNA polyubiquitin ligase and DNA-dependent ATPase in yeast, is orthologous to putative tumor suppressors and controls error-free damage bypass by an unknown mechanism. To identify the mechanism in vivo, we investigated the roles of Rad5 and analyzed the DNA structures that form during damage bypass at site-specific stalled forks present at replication origins. Rad5 mediated the formation of recombination-dependent, X-shaped DNA structures containing Holliday junctions between sister chromatids. Mutants lacking these damage-induced chromatid junctions were defective in resolving stalled forks, restarting replication, and completing chromosome duplication. Rad5 polyubiquitin ligase and ATPase domains both contributed to replication fork recombination. Our results indicate that multiple activities of Rad5 function coordinately with homologous recombination factors to enable replication template switch events that join sister chromatids at stalled forks and bypass DNA damage. PMID:20541998

  20. Alpha-latrotoxin modulates the secretory machinery via receptor-mediated activation of protein kinase C.

    Science.gov (United States)

    Liu, Jie; Wan, Qunfang; Lin, Xianguang; Zhu, Hongliang; Volynski, Kirill; Ushkaryov, Yuri; Xu, Tao

    2005-09-01

    The hypothesis whether alpha-latrotoxin (LTX) could directly regulate the secretory machinery was tested in pancreatic beta cells using combined techniques of membrane capacitance (Cm) measurement and Ca2+ uncaging. Employing ramp increase in [Ca2+]i to stimulate exocytosis, we found that LTX lowers the Ca2+ threshold required for exocytosis without affecting the size of the readily releasable pool (RRP). The burst component of exocytosis in response to step-like [Ca2+]i increase generated by flash photolysis of caged Ca2+ was also speeded up by LTX treatment. LTX increased the maximum rate of exocytosis compared with control responses with similar postflash [Ca2+]i and shifted the Ca2+ dependence of the exocytotic machinery toward lower Ca2+ concentrations. LTXN4C, a LTX mutant which cannot form membrane pores or penetrate through the plasma membrane but has similar affinity for the receptors as the wild-type LTX, mimicked the effect of LTX. Moreover, the effects of both LTX and LTXN4C) were independent of intracellular or extracellular Ca2+ but required extracellular Mg2+. Our data propose that LTX, by binding to the membrane receptors, sensitizes the fusion machinery to Ca2+ and, hence, may permit release at low [Ca2+]i level. This sensitization is mediated by activation of protein kinase C. PMID:16101679

  1. Thermodynamics of tryptophan-mediated activation of the trp RNA-binding attenuation protein.

    Science.gov (United States)

    McElroy, Craig A; Manfredo, Amanda; Gollnick, Paul; Foster, Mark P

    2006-06-27

    The trp RNA-binding attenuation protein (TRAP) functions in many bacilli to control the expression of the tryptophan biosynthesis genes. Transcription of the trp operon is controlled by TRAP through an attenuation mechanism, in which competition between two alternative secondary-structural elements in the 5' leader sequence of the nascent mRNA is influenced by tryptophan-dependent binding of TRAP to the RNA. Previously, NMR studies of the undecamer (11-mer) suggested that tryptophan-dependent control of RNA binding by TRAP is accomplished through ligand-induced changes in protein dynamics. We now present further insights into this ligand-coupled event from hydrogen/deuterium (H/D) exchange analysis, differential scanning calorimetry (DSC), and isothermal titration calorimetry (ITC). Scanning calorimetry showed tryptophan dissociation to be independent of global protein unfolding, while analysis of the temperature dependence of the binding enthalpy by ITC revealed a negative heat capacity change larger than expected from surface burial, a hallmark of binding-coupled processes. Analysis of this excess heat capacity change using parameters derived from protein folding studies corresponds to the ordering of 17-24 residues per monomer of TRAP upon tryptophan binding. This result is in agreement with qualitative analysis of residue-specific broadening observed in TROSY NMR spectra of the 91 kDa oligomer. Implications for the mechanism of ligand-mediated TRAP activation through a shift in a preexisting conformational equilibrium and an induced-fit conformational change are discussed. PMID:16784236

  2. Repressed PKCδ activation in glycodelin-expressing cells mediates resistance to phorbol ester and TGFβ.

    Science.gov (United States)

    Hautala, Laura C; Koistinen, Riitta; Koistinen, Hannu

    2016-10-01

    Glycodelin is a glycoprotein mainly expressed in well-differentiated epithelial cells in reproductive tissues. In normal secretory endometrium, the expression of glycodelin is abundant and regulated by progesterone. In hormone-related cancers glycodelin expression is associated with well-differentiated tumors. We have previously found that glycodelin drives epithelial differentiation of HEC-1B endometrial adenocarcinoma cells, resulting in reduced tumor growth in a preclinical mouse model. Here we show that glycodelin-transfected HEC-1B cells have repressed protein kinase C delta (PKCδ) activation, likely due to downregulation of PDK1, and are resistant to phenotypic change and enhanced migration induced by phorbol 12-myristate 13-acetate (PMA). In control cells, which do not express glycodelin, the effects of PMA were abolished by using PKCδ and PDK1 inhibitors, and knockdown of PKCδ, MEK1 and 2, or ERK1 and 2 by siRNAs. Similarly, transforming growth factor β (TGFβ)-induced phenotypic change was only seen in control cells, not in glycodelin-producing cells, and it was mediated by PKCδ. Taken together, these results strongly suggest that PKCδ, via MAPK pathway, is involved in the glycodelin-driven cell differentiation rendering the cells resistant to stimulation by PMA and TGFβ. PMID:27373413

  3. Role of furanocoumarin derivatives on grapefruit juice-mediated inhibition of human CYP3A activity.

    Science.gov (United States)

    Guo, L Q; Fukuda, K; Ohta, T; Yamazoe, Y

    2000-07-01

    With juices of grapefruit and related fruits, possible relationships between contents of six different furanocoumarins and extents of inhibition of microsomal CYP3A activity have been studied in vitro. Microsomal CYP3A-mediated testosterone 6beta-hydroxylation was inhibited by the addition of a fruit juice (2.5%, v/v) from eight different grapefruit sources, two sweeties, three pomelos, and one sour orange, whereas no clear inhibition was observed with two sweet orange juices. The inhibitory component in grapefruit juice resides mainly in the precipitate rather than in the supernatant after centrifugation. Higher amounts of (R)-6',7'-dihydroxybergamottin (DHB) were distributed in the supernatant, whereas GF-I-1, GF-I-2, GF-I-4, and the newly isolated GF-I-5 and GF-I-6 were detected predominantly in the precipitate. Mixing of five representative furanocoumarins at their detectable levels in grapefruit juice reproduced roughly the inhibitory potencies of grapefruit juice, but omission of any of the components resulted in decreased potencies. These results suggested that all the major furanocoumarins contributed to the CYP3A inhibitory properties of grapefruit juice. Furthermore, all six furanocoumarins showed stronger CYP3A inhibitory potencies after preincubation in the presence of NADPH, suggesting that both competitive and mechanism-based inhibition occur in a grapefruit juices-drug interaction. PMID:10859150

  4. TRAIL-mediated killing of acute lymphoblastic leukemia by plasmacytoid dendritic cell-activated natural killer cells.

    Science.gov (United States)

    Lelaidier, Martin; Dìaz-Rodriguez, Yildian; Cordeau, Martine; Cordeiro, Paulo; Haddad, Elie; Herblot, Sabine; Duval, Michel

    2015-10-01

    Acute lymphoblastic leukemia (ALL) still frequently recurs after hematopoietic stem cell transplantation (HSCT), underscoring the need to improve the graft-versus-leukemia (GvL) effect. Natural killer (NK) cells reconstitute in the first months following HSCT when leukemia burden is at its lowest, but ALL cells have been shown to be resistant to NK cell-mediated killing. We show here that this resistance is overcome by NK cell stimulation with TLR-9-activated plasmacytoid dendritic cells (pDCs). NK cell priming with activated pDCs resulted in TRAIL and CD69 up-regulation on NK cells and IFN-γ production. NK cell activation was dependent on IFN-α produced by pDCs, but was not reproduced by IFN-α alone. ALL killing was further enhanced by inhibition of KIR engagement. We showed that ALL lysis was mainly mediated by TRAIL engagement, while the release of cytolytic granules was involved when ALL expressed NK cell activating receptor ligands. Finally, adoptive transfers of activated-pDCs in ALL-bearing humanized mice delayed the leukemia onset and cure 30% of mice. Our data therefore demonstrate that TLR-9 activated pDCs are a powerful tool to overcome ALL resistance to NK cell-mediated killing and to reinforce the GvL effect of HSCT. These results open new therapeutic avenues to prevent relapse in children with ALL. PMID:26320191

  5. [A case of primary aldosteronism presenting hypokalemic myopathy induced by benidipine hydrochloride; a dihydropyridine calcium channel blocker].

    Science.gov (United States)

    Sugawara, H; Shiraiwa, H; Otsuka, M; Ueki, A

    2000-05-01

    We report a 46-year-old man with primary aldosteronism presenting hypokalemia, periodic paralysis and hypokalemic myopathy whose clinical course paralleled with the dosage of benidipine hydrochloride, a dihydropyridine calcium channel blocker (DHP-CCB), administered for the treatment of hypertension. To see relations between DHP-CCB and episodes of motor weakness in patients with primary aldosteronism, we surveyed retrospectively the history of motor weakness and anti-hypertensive drugs in 14 consecutive cases with primary aldosteronism in our institute. Five patients out of 11 cases (45.5%) who had received DHP-CCB experienced muscle weakness, however, the rest of three patients receiving other anti-hypertensive drug had not experienced weakness. Though, less attention has been paid as thiazide diuretics, it is reported that DHP-CCB also induces hypokalemia through several mechanisms. However, the occurrence of motor weakness by DHP-CCB is very rare. Our results show that primary aldosteronism should be taken into account when we encounter patients manifesting episodic motor weakness by the use of DHP-CCB. PMID:11002726

  6. COUP-TFII mediates progesterone regulation of uterine implantation by controlling ER activity.

    Directory of Open Access Journals (Sweden)

    Isao Kurihara

    2007-06-01

    Full Text Available Progesterone and estrogen are critical regulators of uterine receptivity. To facilitate uterine remodeling for embryo attachment, estrogen activity in the uterine epithelia is attenuated by progesterone; however, the molecular mechanism by which this occurs is poorly defined. COUP-TFII (chicken ovalbumin upstream promoter transcription factor II; also known as NR2F2, a member of the nuclear receptor superfamily, is highly expressed in the uterine stroma and its expression is regulated by the progesterone-Indian hedgehog-Patched signaling axis that emanates from the epithelium. To further assess COUP-TFII uterine function, a conditional COUP-TFII knockout mouse was generated. This mutant mouse is infertile due to implantation failure, in which both embryo attachment and uterine decidualization are impaired. Using this animal model, we have identified a novel genetic pathway in which BMP2 lies downstream of COUP-TFII. Epithelial progesterone-induced Indian hedgehog regulates stromal COUP-TFII, which in turn controls BMP2 to allow decidualization to manifest in vivo. Interestingly, enhanced epithelial estrogen activity, which impedes maturation of the receptive uterus, was clearly observed in the absence of stromal-derived COUP-TFII. This finding is consistent with the notion that progesterone exerts its control of implantation through uterine epithelial-stromal cross-talk and reveals that stromal-derived COUP-TFII is an essential mediator of this complex cross-communication pathway. This finding also provides a new signaling paradigm for steroid hormone regulation in female reproductive biology, with attendant implications for furthering our understanding of the molecular mechanisms that underlie dysregulation of hormonal signaling in such human reproductive disorders as endometriosis and endometrial cancer.

  7. Lipid-mediated unfolding of 3β-hydroxysteroid dehydrogenase 2 is essential for steroidogenic activity.

    Science.gov (United States)

    Rajapaksha, Maheshinie; Thomas, James L; Streeter, Michael; Prasad, Manoj; Whittal, Randy M; Bell, John D; Bose, Himangshu S

    2011-12-27

    For inner mitochondrial membrane (IMM) proteins that do not undergo N-terminal cleavage, the activity may occur in the absence of a receptor present in the mitochondrial membrane. One such protein is human 3β-hydroxysteroid dehydrogenase 2 (3βHSD2), the IMM resident protein responsible for catalyzing two key steps in steroid metabolism: the conversion of pregnenolone to progesterone and dehydroepiandrosterone to androstenedione. Conversion requires that 3βHSD2 serve as both a dehydrogenase and an isomerase. The dual functionality of 3βHSD2 results from a conformational change, but the trigger for this change remains unknown. Using fluorescence resonance energy transfer, we found that 3βHSD2 interacted strongly with a mixture of dipalmitoylphosphatidylglycerol (DPPG) and dipalmitoylphosphatidylcholine (DPPC). 3βHSD2 became less stable when incubated with the individual lipids, as indicated by the decrease in thermal denaturation (T(m)) from 42 to 37 °C. DPPG, alone or in combination with DPPC, led to a decrease in α-helical content without an effect on the β-sheet conformation. With the exception of the 20 N-terminal amino acids, mixed vesicles protected 3βHSD2 from trypsin digestion. However, protein incubated with DPPC was only partially protected. The lipid-mediated unfolding completely supports the model in which a cavity forms between the α-helix and β-sheet. As 3βHSD2 lacks a receptor, opening the conformation may activate the protein. PMID:22106846

  8. CHAPERONIN 20 mediates iron superoxide dismutase (FeSOD) activity independent of its co-chaperonin role in Arabidopsis chloroplasts.

    Science.gov (United States)

    Kuo, W Y; Huang, C H; Liu, A C; Cheng, C P; Li, S H; Chang, W C; Weiss, C; Azem, A; Jinn, T L

    2013-01-01

    Iron superoxide dismutases (FeSODs; FSDs) are primary antioxidant enzymes in Arabidopsis thaliana chloroplasts. The stromal FSD1 conferred the only detectable FeSOD activity, whereas the thylakoid membrane- and nucleoid-co-localized FSD2 and FSD3 double mutant showed arrested chloroplast development. FeSOD requires cofactor Fe for its activity, but its mechanism of activation is unclear. We used reversed-phase high-performance liquid chromatography (HPLC), gel filtration chromatography, LC-MS/MS, protoplast transient expression and virus-induced gene silencing (VIGS) analyses to identify and characterize a factor involved in FeSOD activation. We identified the chloroplast-localized co-chaperonin CHAPERONIN 20 (CPN20) as a mediator of FeSOD activation by direct interaction. The relationship between CPN20 and FeSOD was confirmed by in vitro experiments showing that CPN20 alone could enhance FSD1, FSD2 and FSD3 activity. The in vivo results showed that CPN20-overexpressing mutants and mutants with defective co-chaperonin activity increased FSD1 activity, without changing the chaperonin CPN60 protein level, and VIGS-induced downregulation of CPN20 also led to decreased FeSOD activity. Our findings reveal that CPN20 can mediate FeSOD activation in chloroplasts, a role independent of its known function in the chaperonin system. PMID:23057508

  9. Zinc-mediated regulation of caspases activity: dose-dependent inhibition or activation of caspase-3 in the human Burkitt lymphoma B cells (Ramos).

    Science.gov (United States)

    Schrantz, N; Auffredou, M T; Bourgeade, M F; Besnault, L; Leca, G; Vazquez, A

    2001-02-01

    Divalent cations, including Zinc and Manganese ions, are important modulators of cell activation. We investigated the ability of these two divalent cations to modulate apoptosis in human Burkitt lymphoma B cells line (Ramos). We found that Zinc (from 10 to 50 microM) inhibited Manganese-induced caspase-3 activation and apoptosis of Ramos cells. Higher concentration of Zinc (50 to 100 microM) did not prevent Manganese-mediated apoptosis but rather increased cell death among Ramos cells. This Zinc-mediated cell death was associated with apoptotic features such as cell shrinkage, the presence of phosphatidylserine residues on the outer leaflet of the cells, chromatin condensation, DNA fragmentation and decrease of mitochondrial transmembrane potential. Zinc-mediated apoptosis was associated with caspase-9 and caspase-3 activation as revealed by the appearance of active p35 fragment of caspase-9 and p19 and p17 of caspase-3 as well as in vivo cleavage of PARP and of a cell-permeable fluorogenic caspase-3 substrate (Phiphilux-G(1)D(2)). Both Zinc-mediated apoptosis and caspase-3 activation were prevented by the cell-permeable, broad-spectrum inhibitor of caspases (zVAD-fmk) or overexpression of bcl-2. In addition, we show that Zinc-induced loss of transmembrane mitochondrial potential is a caspase-independent event, since it is not modified by the presence of zVAD-fmk, which is inhibited by overexpression of bcl-2. These results indicate that depending on its concentration, Zinc can exert opposite effects on caspase-3 activation and apoptosis in human B lymphoma cells: concentrations below 50 microM inhibit caspase-3 activation and apoptosis whereas higher concentrations of Zinc activate a death pathway associated with apoptotic-like features and caspase-3 activation. PMID:11313717

  10. Exploring Mediators of Physical Activity in Young Adult Cancer Survivors: Evidence from a Randomized Trial of a Facebook-Based Physical Activity Intervention

    OpenAIRE

    Valle, Carmina G.; Tate, Deborah F.; Mayer, Deborah K.; Allicock, Marlyn; Cai, Jianwen

    2015-01-01

    Purpose: This study examined the effects of a physical activity (PA) intervention for young adult cancer survivors on changes in self-efficacy, social support, and self-monitoring and determined whether changes in these social cognitive theory constructs mediated the relationship between the intervention and changes in PA.

  11. The "Romsas in Motion" Community Intervention: Mediating Effects of Psychosocial Factors on Forward Transition in the Stages of Change in Physical Activity

    Science.gov (United States)

    Lorentzen, Catherine; Ommundsen, Yngvar; Jenum, Anne Karen; Holme, Ingar

    2009-01-01

    This study examines whether a community-based physical activity intervention influenced movement in stages of change in physical activity in an adult population, whether any such effect was mediated by psychosocial influences, and whether any such mediations were moderated by sociodemographic or anthropometric factors. The 3-year-long…

  12. Prostate cancer cell-stromal cell crosstalk via FGFR1 mediates antitumor activity of dovitinib in bone metastases.

    Science.gov (United States)

    Wan, Xinhai; Corn, Paul G; Yang, Jun; Palanisamy, Nallasivam; Starbuck, Michael W; Efstathiou, Eleni; Li Ning Tapia, Elsa M; Tapia, Elsa M Li-Ning; Zurita, Amado J; Aparicio, Ana; Ravoori, Murali K; Vazquez, Elba S; Robinson, Dan R; Wu, Yi-Mi; Cao, Xuhong; Iyer, Matthew K; McKeehan, Wallace; Kundra, Vikas; Wang, Fen; Troncoso, Patricia; Chinnaiyan, Arul M; Logothetis, Christopher J; Navone, Nora M

    2014-09-01

    Bone is the most common site of prostate cancer (PCa) progression to a therapy-resistant, lethal phenotype. We found that blockade of fibroblast growth factor receptors (FGFRs) with the receptor tyrosine kinase inhibitor dovitinib has clinical activity in a subset of men with castration-resistant PCa and bone metastases. Our integrated analyses suggest that FGF signaling mediates a positive feedback loop between PCa cells and bone cells and that blockade of FGFR1 in osteoblasts partially mediates the antitumor activity of dovitinib by improving bone quality and by blocking PCa cell-bone cell interaction. These findings account for clinical observations such as reductions in lesion size and intensity on bone scans, lymph node size, and tumor-specific symptoms without proportional declines in serum prostate-specific antigen concentration. Our findings suggest that targeting FGFR has therapeutic activity in advanced PCa and provide direction for the development of therapies with FGFR inhibitors. PMID:25186177

  13. Prostate Cancer Cell–Stromal Cell Cross-Talk via FGFR1 Mediates Antitumor Activity of Dovitinib in Bone Metastases

    Science.gov (United States)

    Wan, Xinhai; Corn, Paul G.; Yang, Jun; Palanisamy, Nallasivam; Starbuck, Michael W.; Efstathiou, Eleni; Li-Ning Tapia, Elsa M.; Zurita, Amado J.; Aparicio, Ana; Ravoori, Murali K.; Vazquez, Elba S.; Robinson, Dan R.; Wu, Yi-Mi; Cao, Xuhong; Iyer, Matthew K.; McKeehan, Wallace; Kundra, Vikas; Wang, Fen; Troncoso, Patricia; Chinnaiyan, Arul M.; Logothetis, Christopher J.; Navone, Nora M.

    2015-01-01

    Bone is the most common site of prostate cancer (PCa) progression to a therapy-resistant, lethal phenotype. We found that blockade of fibroblast growth factor receptors (FGFRs) with the receptor tyrosine kinase inhibitor dovitinib has clinical activity in a subset of men with castration-resistant PCa and bone metastases. Our integrated analyses suggest that FGF signaling mediates a positive feedback loop between PCa cells and bone cells and that blockade of FGFR1 in osteoblasts partially mediates the antitumor activity of dovitinib by improving bone quality and by blocking PCa cell–bone cell interaction. These findings account for clinical observations such as reductions in lesion size and intensity on bone scans, lymph node size, and tumor-specific symptoms without proportional declines in prostate-specific antigen concentration. Our findings suggest that targeting FGFR has therapeutic activity in advanced PCa and provide direction for the development of therapies with FGFR inhibitors. PMID:25186177

  14. Distinct Polymer Architecture Mediates Switching of Complement Activation Pathways at the Nanosphere-Serum Interface: Implications for Stealth Nanoparticle Engineering

    DEFF Research Database (Denmark)

    Hamad, I.; Al-Hanbali, O.; Hunter, A.C.;

    2010-01-01

    Nanoparticles with surface projected polyethyleneoxide (PEO) chains in 'mushroom-brush' and "brush" configurations display stealth properties in systemic circulation and have numerous applications in site specific targeting for controlled drug delivery and release as well as diagnostic Imaging. We...... reactions in some individuals Conformational states of surface chains, arising from the block copolymer poloxamine 908 adsorption, on polystyrene nanoparticles trigger complement activation differently. Alteration of copolymer architecture on nanospheres from mushroom to brush configuration not only....... Notably, the role properdin mediated activation of alternative pathway was only restricted to particles displaying PEO chains in a transition mushroom-brush configuration Since nanoparticle-mediated complement activation is of clinical concern our findings provide a rational basis for improved surface...

  15. HMGB1 mediates endogenous TLR2 activation and brain tumor regression.

    Directory of Open Access Journals (Sweden)

    James F Curtin

    2009-01-01

    Full Text Available BACKGROUND: Glioblastoma multiforme (GBM is the most aggressive primary brain tumor that carries a 5-y survival rate of 5%. Attempts at eliciting a clinically relevant anti-GBM immune response in brain tumor patients have met with limited success, which is due to brain immune privilege, tumor immune evasion, and a paucity of dendritic cells (DCs within the central nervous system. Herein we uncovered a novel pathway for the activation of an effective anti-GBM immune response mediated by high-mobility-group box 1 (HMGB1, an alarmin protein released from dying tumor cells, which acts as an endogenous ligand for Toll-like receptor 2 (TLR2 signaling on bone marrow-derived GBM-infiltrating DCs. METHODS AND FINDINGS: Using a combined immunotherapy/conditional cytotoxic approach that utilizes adenoviral vectors (Ad expressing Fms-like tyrosine kinase 3 ligand (Flt3L and thymidine kinase (TK delivered into the tumor mass, we demonstrated that CD4(+ and CD8(+ T cells were required for tumor regression and immunological memory. Increased numbers of bone marrow-derived, tumor-infiltrating myeloid DCs (mDCs were observed in response to the therapy. Infiltration of mDCs into the GBM, clonal expansion of antitumor T cells, and induction of an effective anti-GBM immune response were TLR2 dependent. We then proceeded to identify the endogenous ligand responsible for TLR2 signaling on tumor-infiltrating mDCs. We demonstrated that HMGB1 was released from dying tumor cells, in response to Ad-TK (+ gancyclovir [GCV] treatment. Increased levels of HMGB1 were also detected in the serum of tumor-bearing Ad-Flt3L/Ad-TK (+GCV-treated mice. Specific activation of TLR2 signaling was induced by supernatants from Ad-TK (+GCV-treated GBM cells; this activation was blocked by glycyrrhizin (a specific HMGB1 inhibitor or with antibodies to HMGB1. HMGB1 was also released from melanoma, small cell lung carcinoma, and glioma cells treated with radiation or temozolomide

  16. Minimum structural requirements for cell membrane leakage-mediated anti-MRSA activity of macrocyclic bis(bibenzyl)s.

    Science.gov (United States)

    Fujii, Kana; Morita, Daichi; Onoda, Kenji; Kuroda, Teruo; Miyachi, Hiroyuki

    2016-05-01

    Macrocyclic bis(bibenzyl)-type phenolic natural products, found exclusively in bryophytes, exhibit potent antibacterial activity towards methicillin-resistant Staphylococcus aureus (anti-MRSA activity). Here, in order to identify the minimum essential structure for cell membrane leakage-mediated anti-MRSA activity of these compounds, we synthesized acyclic fragment structures and evaluated their anti-MRSA activity. The activities of all of the acyclic fragments tested exhibited similar characteristics to those of the macrocycles, i.e., anti-MRSA bactericidal activity, an enhancing effect on influx and efflux of ethidium bromide (EtBr: fluorescent DNA-binder) in Staphylococcus aureus cells, and bactericidal activity towards a Staphylococcus aureus strain resistant to 2-phenoxyphenol (4). The latter result suggests that they have a different mechanism of action from 4, which is a FabI inhibitor previously proposed to be the minimum active fragment of riccardin-type macrocycles. Thus, cyclic structure is not a necessary condition for cell membrane leakage-mediated anti-MRSA activity of macrocyclic bis(bibenzyl)s. PMID:26995530

  17. Prognostic value of semiquantification NP-59 SPECT/CT in primary aldosteronism patients after adrenalectomy

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Ching-Chu; Cheng, Mei-Fang; Tzen, Kai-Yuan; Yen, Ruoh-Fang [National Taiwan University Hospital and National Taiwan University College of Medicine, Department of Nuclear Medicine, Taipei (China); Wu, Vin-Cent; Wu, Kwan-Dun [National Taiwan University Hospital and National Taiwan University College of Medicine, Department of Internal Medicine, Taipei (China); Liu, Kao-Lang [National Taiwan University Hospital and National Taiwan University College of Medicine, Department of Medical Imaging, Taipei (China); Lin, Wei-Chou [National Taiwan University Hospital and National Taiwan University College of Medicine, Department of Pathology, Taipei (China); Collaboration: the TAIPAI Study Group

    2014-07-15

    Primary aldosteronism (PA), characterized by an excessive production of aldosterone, affects 5-13 % of patients with hypertension. Accurate strategies are needed for the timely diagnosis of PA to allow curability and prevention of excessive cardiovascular events and related damage. This study aimed to evaluate the usefulness of semiquantification of {sup 131}I-6β-iodomethyl-norcholesterol (NP-59) single photon emission computed tomography (SPECT)/CT in differentiating aldosterone-producing adenoma (APA) from idiopathic adrenal hyperplasia (IAH) and in predicting clinical outcomes after adrenalectomy. We retrospectively reviewed 49 PA patients who had undergone adrenalectomy after NP-59 SPECT/CT within 1 year. A conventional visual scale (VS) and two semiquantitative parameters generated from SPECT/CT, adrenal to liver ratio (ALR) and lesion to contralateral ratio of bilateral adrenal glands (CON), with cutoff values calculated by receiver-operating characteristic (ROC) analysis, were compared with pathology results and postsurgical outcomes to determine the accuracy. An ALR cutoff of 1.84 and a CON cutoff of 1.15 showed an ability to distinguish adenoma from hyperplasia similar to VS (p = 0.2592 and 0.1908, respectively). An ALR cutoff of 2.28 and a CON cutoff of 1.11 yielded the highest sensitivity and specificity to predict postsurgical outcomes, and an ALR of 2.28 had an ability superior to VS (p = 0.0215), while a CON of 1.11 did not (p = 0.1015). Patients with either ALR or CON greater than the cutoff had a high probability of positive postsurgical outcomes (n = 36/38), while patients with both ALR and CON less than the cutoff had a low probability of positive postsurgical outcomes (n = 2/11). Semiquantification of NP-59 scintigraphy has an ability similar to VS in differentiating APA from IAH, but an excellent ability to predict postsurgical outcomes of adrenalectomy. An ALR or CON greater than the cutoff strongly suggests benefits from adrenalectomy, and

  18. A systematic review on randomized control trials on rennin angiotensin aldosterone system inhibitors role in managing hypertension among hemodialysis patients.

    Science.gov (United States)

    Aftab, Raja Ahsan; Khan, Amer Hayat; Adnan, Azreen Syazril; Jannah, Nurul

    2016-01-01

    Randomized control trials (RCTs) are considered as most rigors way of determining the cause-effect relationship of a treatment and outcome. Activation of rennin angiotensin aldosterone system (RAAS) is an important contributor to hypertension in hemodialysis patients. The prevalence of hypertension in hemodialysis patients varies from 60% to 80% and hypertension management alone with conventional hemodialysis is insufficient. Hence, the current review was aimed to investigate the effect of RAAS inhibitors in managing hypertension among hemodialysis patients in a randomized control trial. Using PUBMED and EMBASE databases, randomized control trial with primary or secondary outcomes related to the effect of RAAS inhibitors on blood pressure among hemodialysis patients were included for analysis. The current review also assessed the quality of reporting of RCT. A total of eight RCT met inclusion criteria for current review. According to modified jaded scale, one (12.5%) study scored four points for quality reporting, whereas two (25%) studies scored one point that was the least score. The mean score for all included studies was 2.25. Six (75%) of the eight RCT included, involved ARB in hypertension management among hemodialysis patients, whereas two (25%) studies involved angiotensin-converting enzyme (ACE) inhibitors. Of the siz RCT involving ARB, two (33.3%) RCT also included ACE inhibitors comparison group. Altogether six (75%) studies report a reduction in blood pressure with the use of RAAS inhibitors compared to control group; however, of the six studies, two (33.3%) reported that the reduction in blood pressure was not significant. Whereas, two (25%) studies reported no reduction in blood pressure compared to the control group. The findings from current review do not indicate a clear pattern for a role of RAAS inhibitors for hypertension control among hemodialysis patients. PMID:26853680

  19. EGFR-mediated carcinoma cell metastasis mediated by integrin αvβ5 depends on activation of c-Src and cleavage of MUC1.

    Directory of Open Access Journals (Sweden)

    Steven K M Lau

    Full Text Available Receptor tyrosine kinases and integrins play an essential role in tumor cell invasion and metastasis. We previously showed that EGF and other growth factors induce human carcinoma cell invasion and metastasis mediated by integrin αvβ5 that is prevented by Src blockade. MUC1, a transmembrane glycoprotein, is expressed in most epithelial tumors as a heterodimer consisting of an extracellular and a transmembrane subunit. The MUC1 cytoplasmic domain of the transmembrane subunit (MUC1.CD translocates to the nucleus where it promotes the transcription of a metastatic gene signature associated with epithelial to mesenchymal transition. Here, we demonstrate a requirement for MUC1 in carcinoma cell metastasis dependent on EGFR and Src without affecting primary tumor growth. EGF stimulates Src-dependent MUC1 cleavage and nuclear localization leading to the expression of genes linked to metastasis. Moreover, expression of MUC1.CD results in its nuclear localization and is sufficient for transcription of the metastatic gene signature and tumor cell metastasis. These results demonstrate that EGFR and Src activity contribute to carcinoma cell invasion and metastasis mediated by integrin αvβ5 in part by promoting proteolytic cleavage of MUC1 and highlight the ability of MUC1.CD to promote metastasis in a context-dependent manner. Our findings may have implications for the use and future design of targeted therapies in cancers known to express EGFR, Src, or MUC1.

  20. Primary Aldosteronism

    Science.gov (United States)

    ... Cuidadores Hormones and Health Journey Through the Endocrine System Endocrine Glands and Types of Hormones Brainy Hormones What ... Health Hormones and Health Journey Through the Endocrine System Endocrine Glands and Types of Hormones Brainy Hormones What ...

  1. Chromium reduces the in vitro activity and fidelity of DNA replication mediated by the human cell DNA synthesome

    International Nuclear Information System (INIS)

    Hexavalent chromium Cr(VI) is known to be a carcinogenic metal ion, with a complicated mechanism of action. It can be found within our environment in soil and water contaminated by manufacturing processes. Cr(VI) ion is readily taken up by cells, and is recognized to be both genotoxic and cytotoxic; following its reduction to the stable trivalent form of the ion, chromium(Cr(III)), within cells. This form of the ion is known to impede the activity of cellular DNA polymerase and polymerase-mediated DNA replication. Here, we report the effects of chromium on the activity and fidelity of the DNA replication process mediated by the human cell DNA synthesome. The DNA synthesome is a functional multiprotein complex that is fully competent to carry-out each phase of the DNA replication process. The IC50 of Cr(III) toward the activity of DNA synthesome-associated DNA polymerases α, δ and ε is 15, 45 and 125 μM, respectively. Cr(III) inhibits synthesome-mediated DNA synthesis (IC50 = 88 μM), and significantly reduces the fidelity of synthesome-mediated DNA replication. The mutation frequency induced by the different concentrations of Cr(III) ion used in our assays ranges from 2-13 fold higher than that which occurs spontaneously, and the types of mutations include single nucleotide substitutions, insertions, and deletions. Single nucleotide substitutions are the predominant type of mutation, and they occur primarily at GC base-pairs. Cr(III) ion produces a lower number of transition and a higher number of transversion mutations than occur spontaneously. Unlike Cr(III), Cr(VI) ion has little effect on the in vitro DNA synthetic activity and fidelity of the DNA synthesome, but does significantly inhibit DNA synthesis in intact cells. Cell growth and proliferation is also arrested by increasing concentrations of Cr(VI) ion. Our studies provide evidence indicating that the chromium ion induced decrease in the fidelity and activity of synthesome mediated DNA replication

  2. Inhibition effect of cypermethrin mediated by co-regulators SRC-1 and SMRT in interleukin-6-induced androgen receptor activation.

    Science.gov (United States)

    Wang, Qi; Zhou, Ji-Long; Wang, Hui; Ju, Qiang; Ding, Zhen; Zhou, Xiao-Long; Ge, Xing; Shi, Qiao-Mei; Pan, Chen; Zhang, Jin-Peng; Zhang, Mei-Rong; Yu, Hong-Min; Xu, Li-Chun

    2016-09-01

    It is hypothesized that the pesticide cypermethrin may induce androgen receptor (AR) antagonism via ligand-independent mechanisms. The Real-Time Cell Analysis (RTCA) iCELLigence system was used to investigate the inhibitory effect of cypermethrin on interleukin-6 (IL-6)-induced ligand-independent LNCaP cell growth. Then, the mammalian two-hybrid assays were applied to clarify whether the mechanism of IL-6-induced AR antagonism of cypermethrin was associated with the interactions of the AR and co-activator steroid receptor co-activator-1 (SRC-1) and co-repressor silencing mediator for retinoid and thyroid hormone receptors (SMRT). Cypermethrin inhibited the LNCaP cell growth induced by IL-6. The interactions of AR-SRC-1 and AR-SMRT mediated by IL-6 were suppressed by cypermethrin. The results indicate that the IL-6-mediated AR antagonism induced by cypermethrin is related to repress the recruitment of co-regulators SRC-1 and SMRT to the AR in a ligand-independent manner. Inhibition of the interactions of AR-SRC-1 and AR-SMRT mediated by IL-6 contributes to the AR antagonism induced by cypermethrin. PMID:27239967

  3. Feline immunodeficiency virus envelope glycoprotein mediates apoptosis in activated PBMC by a mechanism dependent on gp41 function

    International Nuclear Information System (INIS)

    Feline Immunodeficiency Virus (FIV) is a lentivirus that causes immunodeficiency in cats, which parallels HIV-1-induced immunodeficiency in humans. It has been established that HIV envelope (Env) glycoprotein mediates T cell loss via a mechanism that requires CXCR4 binding. The Env glycoprotein of FIV, similar to HIV, requires CXCR4 binding for viral entry, as well as inducing membrane fusion leading to syncytia formation. However, the role of FIV Env in T cell loss and the molecular mechanisms governing this process have not been elucidated. We studied the role of Env glycoprotein in FIV-mediated T cell apoptosis in an in vitro model. Our studies demonstrate that membrane-expressed FIV Env induces apoptosis in activated feline peripheral blood mononuclear cells (PBMC) by a mechanism that requires CXCR4 binding, as the process was inhibited by CXCR4 antagonist AMD3100 in a dose-dependent manner. Interestingly, studies regarding the role of CD134, the recently identified primary receptor of FIV, suggest that binding to CD134 may not be important for induction of apoptosis in PBMC. However, inhibiting Env-mediated fusion post CXCR4 binding by FIV gp41-specific fusion inhibitor also inhibited apoptosis. Under similar conditions, a fusion-defective gp41 mutant was unable to induce apoptosis in activated PBMC. Our findings are the first report suggesting the potential of FIV Env to mediate apoptosis in bystander cells by a process that is dependent on gp41 function

  4. Low LET radiation-induced telomerase catalytic subunit promoter activation is mediated by nuclear factor Kappa B

    International Nuclear Information System (INIS)

    Full text: The objective of this study is to understand whether low doses of low LET radiation induces survival advantage in normal cells. As an increase in telomerase activity is associated with longevity and cell proliferation, we examined the telomerase response following gamma-irradiation in normal aortic endothelial cells. Telomeric Repeat Amplification Protocol assay following low LET radiation showed an increase in telomerase enzyme activity as early as 8 h post irradiation and reaches its maximum at 24 h. Subsequent analysis revealed that the increased telomerse enzyme activity is due to increased synthesis resulting from an increased transcription. Examination of transcriptional activation of telomerase reverse transcriptase (TERT) promoter regulation showed an enhanced transcription of the telomerse gene following gamma-irradiation. In our previous reports we documented an increase in NF-kB DNA-binding property following low LET radiation (3). Therefore, to determine whether the activation of NF-kB-signaling is responsible for induced TERT promoter activation, cells transiently transfected with minimal promoter region of TERT containing wild type or mutant NF-kB binding site were examined following low LET radiation. TERT promoter activation was induced in wild type transfected cells whereas, in mutant kB binding site, the activation remained at the basal level similar to that of un-irradiated cells. More significantly, the gamma-ray mediated promoter activation of telomerase gene as well as induce telomerase enzyme activity was abrogated by ectopically expressing the IkBa mutant (IkBa (S32A/S36A)), which blocks NF-kB activation. The results thus suggest that exposure to low LET radiation could induce telomerase activity and the activation is at least, in part, mediated by the transcription factor NF-kB. Sustained activation of telomerase in these cells after low LET radiation may impart extended life span

  5. Stat3 activation of NF-κB p100 processing involves CBP/p300-mediated acetylation

    OpenAIRE

    Nadiminty, Nagalakshmi; Lou, Wei; Lee, Soo Ok; Lin, Xin; Trump, Donald L.; Gao, Allen C.

    2006-01-01

    Activation of the noncanonical NF-κB signaling pathway involved in the proteolytic processing of NF-κB p100 to p52 is tightly regulated, and overproduction of p52 leads to lymphocyte hyperplasia and transformation. We have demonstrated that active but not latent Stat3, expressed in many types of human cancers involved in cell proliferation and survival, induces p100 processing to p52 by activation of IKKα and subsequent phosphorylation of p100. The Stat3-mediated p100 processing to p52 requir...

  6. Plant mediated green synthesis and antibacterial activity of silver nanoparticles using Emblica officinalis fruit extract

    Science.gov (United States)

    Ramesh, P. S.; Kokila, T.; Geetha, D.

    2015-05-01

    A green straight forward method of synthesizing silver nanoparticles (AgNPs) in an aqueous medium was designed using Emblica officinalis (EO) fruit extract as stabilizer and reducer. The formation of AgNPs depends on the effect of extract concentration and pH were studied. The AgNPs was synthesized using E.officinalis (fruit extract) and nanoparticles were characterized using UV-Vis spectrophotometer, the presence of biomolecules of E.officinalis capped in AgNPs was found by FT-IR analysis, shape and size were examined by SEM and XRD. The XRD analysis respects the Bragg's law and confirmed the crystalline nature of silver nanoparticles. From XRD the average size of AgNPs was found to be around 15 nm. AFM has proved to be very helpful in the determination and verification of various morphological features and parameters. EO fruit extract mediated AgNPs was synthesized and confirmed through kinetic behavior of nanoparticles. The shape of the bio-synthesized AgNPs was spherical. Potent biomolecules of E.officinalis such as polyphenols, glucose, and fructose was capped with AgNPs which reduces the toxicity. The synthesized AgNPs were tested for its antibacterial activity against the isolates by disc diffusion method. The obtained results confirmed that the E.officinalis fruit extract is a very good bioreductant for the synthesis of AgNPs. It was investigated that the synthesized AgNPs showed inhibition and had significant antibacterial against both gram-positive and gram-negative bacterial strains.

  7. Transcription factor activating protein 2 beta (TFAP2B) mediates noradrenergic neuronal differentiation in neuroblastoma.

    Science.gov (United States)

    Ikram, Fakhera; Ackermann, Sandra; Kahlert, Yvonne; Volland, Ruth; Roels, Frederik; Engesser, Anne; Hertwig, Falk; Kocak, Hayriye; Hero, Barbara; Dreidax, Daniel; Henrich, Kai-Oliver; Berthold, Frank; Nürnberg, Peter; Westermann, Frank; Fischer, Matthias

    2016-02-01

    Neuroblastoma is an embryonal pediatric tumor that originates from the developing sympathetic nervous system and shows a broad range of clinical behavior, ranging from fatal progression to differentiation into benign ganglioneuroma. In experimental neuroblastoma systems, retinoic acid (RA) effectively induces neuronal differentiation, and RA treatment has been therefore integrated in current therapies. However, the molecular mechanisms underlying differentiation are still poorly understood. We here investigated the role of transcription factor activating protein 2 beta (TFAP2B), a key factor in sympathetic nervous system development, in neuroblastoma pathogenesis and differentiation. Microarray analyses of primary neuroblastomas (n = 649) demonstrated that low TFAP2B expression was significantly associated with unfavorable prognostic markers as well as adverse patient outcome. We also found that low TFAP2B expression was strongly associated with CpG methylation of the TFAP2B locus in primary neuroblastomas (n = 105) and demethylation with 5-aza-2'-deoxycytidine resulted in induction of TFAP2B expression in vitro, suggesting that TFAP2B is silenced by genomic methylation. Tetracycline inducible re-expression of TFAP2B in IMR-32 and SH-EP neuroblastoma cells significantly impaired proliferation and cell cycle progression. In IMR-32 cells, TFAP2B induced neuronal differentiation, which was accompanied by up-regulation of the catecholamine biosynthesizing enzyme genes DBH and TH, and down-regulation of MYCN and REST, a master repressor of neuronal genes. By contrast, knockdown of TFAP2B by lentiviral transduction of shRNAs abrogated RA-induced neuronal differentiation of SH-SY5Y and SK-N-BE(2)c neuroblastoma cells almost completely. Taken together, our results suggest that TFAP2B is playing a vital role in retaining RA responsiveness and mediating noradrenergic neuronal differentiation in neuroblastoma. PMID:26598443

  8. Lipocalin 2, a Regulator of Retinoid Homeostasis and Retinoid-mediated Thermogenic Activation in Adipose Tissue.

    Science.gov (United States)

    Guo, Hong; Foncea, Rocio; O'Byrne, Sheila M; Jiang, Hongfeng; Zhang, Yuanyuan; Deis, Jessica A; Blaner, William S; Bernlohr, David A; Chen, Xiaoli

    2016-05-20

    We have recently characterized the role of lipocalin 2 (Lcn2) as a new adipose-derived cytokine in the regulation of adaptive thermogenesis via a non-adrenergic pathway. Herein, we explored a potential non-adrenergic mechanism by which Lcn2 regulates thermogenesis and lipid metabolism. We found that Lcn2 is a retinoic acid target gene, and retinoic acid concurrently stimulated UCP1 and Lcn2 expression in adipocytes. Lcn2 KO mice exhibited a blunted effect of all-trans-retinoic acid (ATRA) on body weight and fat mass, lipid metabolism, and retinoic acid signaling pathway activation in adipose tissue under the high fat diet-induced obese condition. We further demonstrated that Lcn2 is required for the full action of ATRA on the induction of UCP1 and PGC-1α expression in brown adipocytes and the restoration of cold intolerance in Lcn2 KO mice. Interestingly, we discovered that Lcn2 KO mice have decreased levels of retinoic acid and retinol in adipose tissue. The protein levels of STRA6 responsible for retinol uptake were significantly decreased in adipose tissue. The retinol transporter RBP4 was increased in adipose tissue but decreased in the circulation, suggesting the impairment of RBP4 secretion in Lcn2 KO adipose tissue. Moreover, Lcn2 deficiency abolished the ATRA effect on RBP4 expression in adipocytes. All the data suggest that the decreased retinoid level and action are associated with impaired retinol transport and storage in adipose tissue in Lcn2 KO mice. We conclude that Lcn2 plays a critical role in regulating metabolic homeostasis of retinoids and retinoid-mediated thermogenesis in adipose tissue. PMID:27008859

  9. Spinal activity of interleukin 6 mediates myelin basic protein-induced allodynia.

    Science.gov (United States)

    Ko, Justin S; Eddinger, Kelly A; Angert, Mila; Chernov, Andrei V; Dolkas, Jennifer; Strongin, Alex Y; Yaksh, Tony L; Shubayev, Veronica I

    2016-08-01

    Mechanosensory fibers are enveloped by myelin, a unique multilamellar membrane permitting saltatory neuronal conduction. Damage to myelin is thought to contribute to severe pain evoked by innocuous tactile stimulation (i.e., mechanical allodynia). Our earlier (Liu et al., 2012) and present data demonstrate that a single injection of a myelin basic protein-derived peptide (MBP84-104) into an intact sciatic nerve produces a robust and long-lasting (>30days) mechanical allodynia in female rats. The MBP84-104 peptide represents the immunodominant epitope and requires T cells to maintain allodynia. Surprisingly, only systemic gabapentin (a ligand of voltage-gated calcium channel α2δ1), but not ketorolac (COX inhibitor), lidocaine (sodium channel blocker) or MK801 (NMDA antagonist) reverse allodynia induced by the intrasciatic MBP84-104. The genome-wide transcriptional profiling of the sciatic nerve followed by the bioinformatics analyses of the expression changes identified interleukin (IL)-6 as the major cytokine induced by MBP84-104 in both the control and athymic T cell-deficient nude rats. The intrasciatic MBP84-104 injection resulted in both unilateral allodynia and unilateral IL-6 increase the segmental spinal cord (neurons and astrocytes). An intrathecal delivery of a function-blocking IL-6 antibody reduced the allodynia in part by the transcriptional effects in large-diameter primary afferents in DRG. Our data suggest that MBP regulates IL-6 expression in the nervous system and that the spinal IL-6 activity mediates nociceptive processing stimulated by the MBP epitopes released after damage or disease of the somatosensory nervous system. PMID:26970355

  10. Oral and inhaled corticosteroids: Differences in P-glycoprotein (ABCB1) mediated efflux

    International Nuclear Information System (INIS)

    There is concern that P-glycoprotein mediated efflux contributes to steroid resistance. Therefore, this study examined bidirectional corticosteroid transport and induction capabilities for P-glycoprotein (P-gp) to understand which of the systemic and inhaled corticosteroids interacted with P-gp to the greatest extent. Hydrocortisone, prednisolone, prednisone, methylprednisolone, and dexamethasone represented systemically active drugs, while fluticasone propionate, beclomethasone dipropionate, ciclesonide and budesonide represented inhaled corticosteroids. Aldosterone and fludrocortisone represented mineralocorticoids. All drugs were detected using individually optimised HPLC protocols. Transport studies were conducted through Caco-2 monolayers. Hydrocortisone and aldosterone had efflux ratios below 1.5, while prednisone showed a P-gp mediated efflux ratio of only 1.8 compared to its active drug, prednisolone, with an efflux ratio of 4.5. Dexamethasone and beclomethasone had efflux ratios of 2.1 and 3.3 respectively, while this increased to 5.1 for methylprednisolone. Fluticasone showed an efflux ratio of 2.3. Protein expression studies suggested that all of the inhaled corticosteroids were able to induce P-gp expression, from 1.6 to 2 times control levels. Most of the systemic corticosteroids had higher passive permeability (> 20 × 10−6 cm/s) compared to the inhaled corticosteroids (> 5 × 10−6 cm/s), except for budesonide, with permeability similar to the systemic corticosteroids. Inhaled corticosteroids are not transported by P-gp to the same extent as systemic corticosteroids. However, they are able to induce P-gp production. Thus, inhaled corticosteroids may have greater interactions with other P-gp substrates, but P-gp itself is less likely to influence resistance to the drugs. -- Highlights: ► Inhaled corticosteroids are only weak substrates for P-gp, including budesonide. ► Inhaled corticosteroid potent P-gp inducers especially fluticasone and

  11. Oral and inhaled corticosteroids: Differences in P-glycoprotein (ABCB1) mediated efflux

    Energy Technology Data Exchange (ETDEWEB)

    Crowe, Andrew, E-mail: a.p.crowe@curtin.edu.au; Tan, Ai May

    2012-05-01

    There is concern that P-glycoprotein mediated efflux contributes to steroid resistance. Therefore, this study examined bidirectional corticosteroid transport and induction capabilities for P-glycoprotein (P-gp) to understand which of the systemic and inhaled corticosteroids interacted with P-gp to the greatest extent. Hydrocortisone, prednisolone, prednisone, methylprednisolone, and dexamethasone represented systemically active drugs, while fluticasone propionate, beclomethasone dipropionate, ciclesonide and budesonide represented inhaled corticosteroids. Aldosterone and fludrocortisone represented mineralocorticoids. All drugs were detected using individually optimised HPLC protocols. Transport studies were conducted through Caco-2 monolayers. Hydrocortisone and aldosterone had efflux ratios below 1.5, while prednisone showed a P-gp mediated efflux ratio of only 1.8 compared to its active drug, prednisolone, with an efflux ratio of 4.5. Dexamethasone and beclomethasone had efflux ratios of 2.1 and 3.3 respectively, while this increased to 5.1 for methylprednisolone. Fluticasone showed an efflux ratio of 2.3. Protein expression studies suggested that all of the inhaled corticosteroids were able to induce P-gp expression, from 1.6 to 2 times control levels. Most of the systemic corticosteroids had higher passive permeability (> 20 × 10{sup −6} cm/s) compared to the inhaled corticosteroids (> 5 × 10{sup −6} cm/s), except for budesonide, with permeability similar to the systemic corticosteroids. Inhaled corticosteroids are not transported by P-gp to the same extent as systemic corticosteroids. However, they are able to induce P-gp production. Thus, inhaled corticosteroids may have greater interactions with other P-gp substrates, but P-gp itself is less likely to influence resistance to the drugs. -- Highlights: ► Inhaled corticosteroids are only weak substrates for P-gp, including budesonide. ► Inhaled corticosteroid potent P-gp inducers especially

  12. HuR represses Wnt/β-catenin-mediated transcriptional activity by promoting cytoplasmic localization of β-catenin

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Inae; Hur, Jung; Jeong, Sunjoo, E-mail: sjsj@dankook.ac.kr

    2015-01-30

    Highlights: • Wnt signaling as well as β-catenin overexpression enhance HuR cytoplasmic export. • HuR overexpression promotes cytoplasmic localization of β-catenin from the perinuclear fraction. • Wnt/β-catenin-mediated transcriptional activity is repressesed by HuR. - Abstract: β-Catenin is the key transcriptional activator of canonical Wnt signaling in the nucleus; thus, nuclear accumulation of β-catenin is a critical step for expressing target genes. β-Catenin accumulates in the nucleus of cancer cells where it activates oncogenic target genes. Hu antigen R (HuR) is a RNA binding protein that regulates multiple post-transcriptional processes including RNA stability. Thus, cytoplasmic HuR protein may be involved in tumorigenesis by stabilizing oncogenic transcripts, but the molecular mechanism remains unclear. Here, we observed that Wnt/β-catenin signaling induced export of the HuR protein, whereas HuR overexpression promoted accumulation of the β-catenin protein in the cytoplasm. Thus, Wnt/β-catenin-mediated transcriptional activity in the nucleus was reduced by overexpressing HuR. These results suggest novel and uncharacterized cytoplasmic β-catenin functions related to HuR-mediated RNA metabolism in cancer cells.

  13. Physical activity as a mediator of the impact of chronic conditions on quality of life in older adults

    Directory of Open Access Journals (Sweden)

    Miller William C

    2007-12-01

    Full Text Available Abstract Background Chronic conditions could negatively affect the quality of life of older adults. This may be partially due to a relative lack of physical activity. We examined whether physical activity mediates the relationship between different chronic conditions and several health outcomes that are important to the quality of life of older adults. Methods The data were taken from the Canadian Community Health Survey (cycle 1.1, a cross-section survey completed in 2001. Only respondents who were 65 years or older were included in our study (N = 22,432. The Health Utilities Index Mark 3 (HUI3 was used to measure overall quality of life, and to measure selected health outcomes (dexterity, mobility, pain, cognition, and emotional wellbeing that are considered to be of importance to the quality of life of older adults. Leisure-time physical activity was assessed by determining weekly energy expenditure (Kcal per week based on the metabolic equivalents of self-reported leisure activities. Linear and logistic regression models were used to determine the mediating effect of leisure-time physical activity while controlling for demographic variables (age and sex, substance use (tobacco use and alcohol consumption, and obesity. Results Having a chronic condition was associated with a relative decrease in health utility scores and a relative increase in mobility limitations, dexterity problems, pain, emotional problems (i.e., decreased happiness, and cognitive limitations. These negative consequences could be partially attributed to a relative lack of physical activity in older adults with a chronic condition (14% mediation for the HUI3 score. The corresponding degree of mediation was 18% for mobility limitations, 5% for pain, and 13% for emotional wellbeing (statistically significant mediation was not observed for the other health attributes. These values varied with respect to the different chronic conditions examined in our study. Conclusion Older

  14. The PGE(2)-EP4 receptor is necessary for stimulation of the renin-angiotensin-aldosterone system in response to low dietary salt intake in vivo

    DEFF Research Database (Denmark)

    Pöschke, Antje; Kern, Niklas; Maruyama, Takayuki; Pavenstädt, Hermann; Narumiya, Shuh; Jensen, Boye L; Nüsing, Rolf M

    2012-01-01