Citations
All
Search in:AllTitleAbstractAuthor name
Publications
(12K+)
Patents
Grants
Pathways
Clinical trials
Publication
Journal: Pulmonary Circulation
June/23/2014
Abstract
Most subtypes of pulmonary arterial hypertension (PAH) are characterized by a greater susceptibility to disease among females, although females with PAH appear to live longer after diagnosis. While this "estrogen paradoxȍ of enhanced female survival despite increased female susceptibility remains a mystery, recent progress has begun to shed light upon the interplay of sex hormones, the pathogenesis of pulmonary hypertension, and the right ventricular response to stress. For example, emerging data in humans and experimental models suggest that estrogens or differential sex hormone metabolism may modify disease risk among susceptible subjects, and that estrogens may interact with additional local factors such as serotonin to enhance the potentially damaging chronic effects of estrogens on the pulmonary vasculature. Regardless, it remains unclear why not all estrogenic compounds behave equally, nor why estrogens appear to be protective in certain settings but detrimental in others. The contribution of androgens and other compounds, such as dehydroepiandrosterone, to pathogenesis and possibly treatment must be considered as well. In this review, we will discuss the recent understandings on how estrogens, estrogen metabolism, dehydroepiandrosterone, and additional susceptibility factors may all contribute to the pathogenesis or potentially to the treatment of pulmonary hypertension, by evaluating current human, cell-based, and experimental model data.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
July/18/2004
Abstract
Associations between low birth weight and higher adrenal androgen secretion before puberty have yet only been reported in case-control studies in girls. We examined the influence of birth weight and early postnatal weight gain on overnight-fasting adrenal androgen and cortisol levels in 770 children from a large normal United Kingdom birth cohort at age 8 yr. In univariate analyses, adrenal androgen levels were inversely related to birth weight sd score in each sex [dehydroepiandrosterone sulfate in boys: regression coefficient (B) = -2.5 microg/dl/SD; 95% confidence interval (CI), -4.7 to -0.2; in girls: B = -3.8 microg/dl/SD; 95% CI, -6.2 to -1.4; androstenedione in boys: B = -0.15 nmol/liter/sd, 95% CI, -0.25 to -0.6; in girls: B = -0.13 nmol/liter/SD; 95% CI, -0.24 to -0.02). In multivariate analyses, both lower birth weight and larger current body weight predicted higher adrenal androgen levels (P < 0.005 for all comparisons). Allowing for current weight, children who showed rapid postnatal weight gain between 0 and 3 yr had higher dehydroepiandrosterone sulfate (P = 0.002) and androstenedione (P = 0.004) levels at 8 yr. In contrast, cortisol levels were unrelated to birth weight or current body size. In summary, the relationship between lower birth weight and higher childhood adrenal androgen levels was continuous throughout the range of normal birth weights, and was similar in boys and girls. Adrenal androgen levels were highest in small infants who gained weight rapidly during early childhood. We suggest that higher adrenal androgen secretion could contribute to links between early growth and adult disease risks, possibly by enhancing insulin resistance and central fat deposition.
Publication
Journal: Chemical Research in Toxicology
June/17/2007
Abstract
Polychlorinated biphenyls (PCBs) are important persistent environmental contaminants. PCBs can be metabolically converted to their hydroxylated metabolites (OHPCBs), and in recent years, these OHPCBs have been observed to inhibit human sulfotransferases (SULTs) such as the phenol SULTs (SULT family-1) involved in the metabolism of estrogen and various other endogenous and xenobiotic phenols. In the present study, we have investigated the hypothesis that OHPCBs interact with family 2 hydroxysteroid (alcohol) SULTs (e.g., human SULT2A1), enzymes that are physiologically important for the metabolic transformations of several key endogenous hydroxysteroids as well as xenobiotic alcohols. We have examined the interactions of three OHPCBs with purified recombinant human SULT2A1 (also known as either human DHEA-ST or ST2A3). These studies with SULT2A1 were carried out on 4'-hydroxy-2,5-dichlorobiphenyl (4'-OH PCB 9), 4-hydroxy-2',3,5-trichlorobiphenyl (4-OH PCB 34), and 4'-hydroxy-2,3',4,5'-tetrachlorobiphenyl (4'-OH PCB 68). Our results showed that 4-OH PCB 34 and 4'-OH PCB 68 were substrates for SULT2A1, and 4-OH PCB 34 exhibited substrate inhibition similar to that seen with the physiological substrate dehydroepiandrosterone (DHEA). Although the sulfation of 4-OH PCB 34 and 4'-OH PCB 68 represents a potential metabolic route for these compounds, these OHPCBs may also compete with other xenobiotic substrates as well as endogenous substrates for SULT2A1. The third OHPCB studied, 4'-OH PCB 9, was not a substrate for SULT2A1 but was an inhibitor of the enzyme. Thus, the interactions of OHPCBs with human SULT2A1 represent both a potential route of metabolism and a possible source of interference with sulfation reactions catalyzed by this enzyme.
Publication
Journal: Arthritis and rheumatism
November/21/1988
Abstract
Serum concentrations of luteinizing hormone, follicle-stimulating hormone, prolactin, 17 beta-estradiol, testosterone, androstenedione, dehydrotestosterone, dehydroepiandrosterone sulfate, and cortisol were examined in 14 men with rheumatoid arthritis (RA) and in age-matched osteoarthritis controls. Hypophyseal, adrenal, and testicular responses to stimulation with luteinizing hormone-releasing hormone, adrenocorticotropin, and human chorionic gonadotropin, respectively, were evaluated in 8 RA patients and in 8 age-matched healthy volunteers. Basal serum testosterone concentrations were significantly lower in male RA patients than in the osteoarthritis control subjects (P less than 0.01). After human chorionic gonadotropin stimulation, serum concentrations of testosterone were also lower in the RA patients than in normal healthy controls (P less than 0.05). These findings suggest that diminished testicular steroid biosynthesis might contribute to the serum testosterone deficiency observed in male RA patients.
Publication
Journal: Journal of Clinical Oncology
September/29/2013
Abstract
OBJECTIVE
In the phase III study COU-AA-301, abiraterone acetate (AA) plus prednisone (P) prolonged overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC) after docetaxel administration. In this article, we investigate the relationship between baseline serum androgen (SA) levels and OS.
METHODS
COU-AA-301 is a randomized, double-blind study of AA (1,000 mg every day) plus P (5 mg by mouth twice daily; n = 797) versus P alone (n = 398). Randomization was stratified by Eastern Cooperative Oncology Group performance status (0 to 1 v 2), pain (Brief Pain Inventory-Short Form over past 24 hours: 4 to 10, present; v 0 to 3, absent), prior chemotherapy (1 v 2), and progression (prostate-specific antigen v radiographic). Association of baseline SA (testosterone, androstenedione, dehydroepiandrosterone sulfate), was measured by ultrasensitive liquid-liquid extraction or protein precipitation and two-dimensional liquid chromatography coupled to mass spectrometry, with OS determined by bivariate and multivariable Cox models. OS was examined with SA as greater than median and less than or equal to the median.
RESULTS
Median survival increased with each quartile increase in testosterone level regardless of treatment arm. SA levels at baseline strongly associated with survival (P < .0001) in bivariate and multivariable analyses. Longer survival was observed for patients with SA above median compared with below median in both the AA and P arms (eg, testosterone, AA; hazard ratio, 0.64; 95% CI, 0.53 to 0.77; P < .0001). Treatment with AA led to longer survival versus P alone in the above- or below-median group for all androgens.
CONCLUSIONS
SA, measured with a novel ultrasensitive assay in COU-AA-301, is prognostic for OS and may be useful for risk stratification in mCRPC clinical trials.
Publication
Journal: Journal of steroid biochemistry
February/22/1988
Abstract
The easy stress-free, non-invasive nature of saliva collection makes it one of the most accessible body fluids and it is potentially of value in studying normal human physiology as well as pathology. Measurements of salivary hormone levels will usually only be of value if they reflect the plasma level of the hormone and the relationship between the saliva and plasma levels of many hormones have been studied by a number of groups. The measurement of the salivary level is a valuable clinical tool for some hormones (e.g. cortisol, oestriol, progesterone), is of little value for others (e.g. cortisone, dehydroepiandrosterone sulphate, thyroxine, pituitary hormones) and for many others the saliva/plasma relationship is not yet sufficiently understood to assess the value of the salivary measurement. As well as reviewing the state of our knowledge of the salivary concentration of many hormones this review outlines a number of "rules of thumb" concerning the presence of hormones in saliva, their saliva/plasma relationship and the potential usefulness of assays of their salivary concentration.
Publication
Journal: Molecular Pharmacology
December/3/2001
Abstract
Vectorial transport of endogenous substances, drugs, and toxins is an important function of polarized cells. We have constructed a double-transfected Madin-Darby canine kidney (MDCK) cell line permanently expressing a recombinant uptake transporter for organic anions in the basolateral membrane and an ATP-dependent export pump for anionic conjugates in the apical membrane. Basolateral uptake was mediated by the human organic anion transporter 8 (OATP8; symbol SLC21A8) and subsequent apical export by the multidrug resistance protein 2 (MRP2; symbol ABCC2). Under physiological conditions, both transport proteins are strongly expressed in hepatocytes and contribute to the hepatobiliary elimination of organic anions. Expression and localization of OATP8 and MRP2 in MDCK cells growing on Transwell membrane inserts was demonstrated by immunoblotting and confocal laser scanning microscopy. (3)H-Labeled sulfobromophthalein (BSP) was a substrate for both transport proteins and was transferred from the basolateral to the apical compartment at a rate at least six times faster by double-transfected MDCK-MRP2/OATP8 cells than by single-transfected MDCK-OATP8 or MDCK-MRP2 cells. Vectorial transport at a much higher rate by double-transfected than by single-transfected cells was also observed for the (3)H-labeled substrates leukotriene C(4), 17 beta-glucuronosyl estradiol, and dehydroepiandrosterone sulfate, for the fluorescent anionic substrate fluo-3, and for the antibiotic rifampicin. Inhibition studies indicated that intracellular formation of S-(2,4-dinitrophenyl)-glutathione from 2,4-chlorodinitrobenzene selectively inhibits the transcellular transport of [(3)H]BSP at the site of MRP2-mediated export. The double-transfected cells provide a useful system for the identification of transport substrates and transport inhibitors including drug candidates.
Publication
Journal: Circulation
October/28/2009
Abstract
BACKGROUND
The remodeled vessel wall in many vascular diseases such as restenosis after injury is characterized by proliferative and apoptosis-resistant vascular smooth muscle cells. There is evidence that proproliferative and antiapoptotic states are characterized by a metabolic (glycolytic phenotype and hyperpolarized mitochondria) and electric (downregulation and inhibition of plasmalemmal K(+) channels) remodeling that involves activation of the Akt pathway. Dehydroepiandrosterone (DHEA) is a naturally occurring and clinically used steroid known to inhibit the Akt axis in cancer. We hypothesized that DHEA will prevent and reverse the remodeling that follows vascular injury.
RESULTS
We used cultured human carotid vascular smooth muscle cell and saphenous vein grafts in tissue culture, stimulated by platelet-derived growth factor to induce proliferation in vitro and the rat carotid injury model in vivo. DHEA decreased proliferation and increased vascular smooth muscle cell apoptosis in vitro and in vivo, reducing vascular remodeling while sparing healthy tissues after oral intake. Using pharmacological (agonists and antagonists of Akt and its downstream target glycogen-synthase-kinase-3beta [GSK-3beta]) and molecular (forced expression of constitutively active Akt1) approaches, we showed that the effects of DHEA were mediated by inhibition of Akt and subsequent activation of GSK-3beta, leading to mitochondrial depolarization, increased reactive oxygen species, activation of redox-sensitive plasmalemmal voltage-gated K(+) channels, and decreased [Ca(2+)](i). These functional changes were accompanied by sustained molecular effects toward the same direction; by decreasing [Ca(2+)](i) and inhibiting GSK-3beta, DHEA inhibited the nuclear factor of activated T cells transcription factor, thus increasing expression of Kv channels (Kv1.5) and contributing to sustained mitochondrial depolarization. These results were independent of any steroid-related effects because they were not altered by androgen and estrogen inhibitors but involved a membrane G protein-coupled receptor.
CONCLUSIONS
We suggest that the orally available DHEA might be an attractive candidate for the treatment of systemic vascular remodeling, including restenosis, and we propose a novel mechanism of action for this important hormone and drug.
Publication
Journal: Psychoneuroendocrinology
March/18/2007
Abstract
Posttraumatic stress disorder (PTSD) has been associated with dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis as well as of the hypothalamus-pituitary-thyroid (HPT) axis. Findings have not been consistent and may depend on methodological issues like controlling for relevant variables. This study examines the levels of six HPA and HPT-axis related hormones in civilian PTSD patients without psychotropic medication. In a cross sectional study, 39 chronic PTSD patients and 44 healthy volunteers were included. Psychometric instruments included SCID, SI-PTSD, IES-R and BDI. The plasma hormones levels assessed were cortisol, dehydroepiandrosterone (DHEA), and dehydroepiandrosterone sulfate (DHEA-S), prolactin, thyrotropin (TSH), and free thyroxin (fT4). Results showed that patients had significantly lower plasma cortisol, prolactin and TSH levels compared to the comparison group. The difference between TSH levels in patients and comparison subjects only emerged after controlling for relevant background variables. Furthermore, the severity of PTSD symptoms was negatively related to cortisol levels. Secondary analyses revealed no statistically significant effect of comorbid depression (26% of patients) on any of the hormone levels. Complex feedback mechanisms are likely to result in altered levels of stress related hormones in PTSD, and results depend on controlling for relevant variables. Further research with longitudinal designs is needed to find out whether these lower hormone levels are preexisting risk factors or consequence of trauma and whether these alterations are deleterious or adaptive.
Publication
Journal: Endocrinology
May/24/1990
Abstract
The isolation, cloning, and expression of a cDNA insert complementary to mRNA encoding human 3 beta-hydroxysteroid dehydrogenase/delta 5----4isomerase is reported. The insert contains an open reading frame encoding a protein of 372 amino acids, the initial 29 amino acids corresponding to the N-terminal sequence identified from the purified human placental microsomal enzyme. The cDNA was inserted into a modified pCMV vector and expressed in COS-1 monkey kidney tumor cells. The expressed protein was similar in size to human placental microsomal 3 beta-hydroxysteroid dehydrogenase/delta 5----4isomerase, as detected by immunoblot analysis, and catalyzed the conversion of 17 alpha-hydroxypregnenolone to 17 alpha-hydroxyprogesterone, pregnenolone to progesterone, and dehydroepiandrosterone to androstenedione. Transfected COS cell homogenates, supplemented with NAD+, very efficiently oxidized 5 alpha-androstan-3 beta,17 beta-diol to 5 alpha-dihydrotestosterone and, upon addition of NADH, reduced 5 alpha-dihydrotestosterone to 5 alpha-androstan-3 beta,17 beta-diol. Thus, the dehydrogenation/isomerization steps of steroid biosynthesis can be catalyzed by a single polypeptide chain, which can metabolize all of the major physiological substrates.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
November/4/1998
Abstract
The objective of this study was to investigate the relation between the peripheral concentrations of the adrenal steroid hormones cortisol and dehydroepiandrosterone sulfate (DHEAS) and cognitive impairment and decline. A prospective study design was used. The setting was a suburb of Rotterdam, The Netherlands. The study population consisted of a sample of 189 healthy participants from the population-based Rotterdam Study, aged 55-80 yr, who were invited for an additional examination. Follow-up examinations took place 1.9 yr after baseline, on the average. We determined fasting blood levels of DHEAS before dexamethasone administration and of cortisol and corticosteroid-binding globulin before and after the administration of 1 mg dexamethasone overnight. The 30-point Mini-Mental State Examination (MMSE) was used to assess cognition. The associations with cognitive impairment (MMSE score of <26; 6% of the sample) and cognitive decline (drop in MMSE score of >1 point/yr; 24%) were estimated using logistic regression, with adjustment for age, sex, education, and depressive symptoms. An increase of 1 SD in the estimate of free cortisol (SD = 30.3) was associated with cognitive impairment, although not significantly [odds ratio (OR) = 1.5; 95% confidence interval (CI), 0.9-2.4]. A 1 SD increase in the natural logarithm of cortisol after the administration of 1 mg dexamethasone (SD = 0.68) was associated with an OR for cognitive decline of 1.5 (95% CI, 1.0-2.3). A 1 SD increase in DHEAS (SD = 2.10 micromol/L) was inversely, but nonsignificantly, related to cognitive impairment (OR = 0.5; 95% CI, 0.2-1.1) and cognitive decline (OR = 0.6; 95% CI, 0.4-1.1). The ratio of free cortisol over DHEAS was significantly related to cognitive impairment (OR = 1.8; 95% CI, 1.0-3.2). This prospective study among healthy elderly subjects suggested that basal free cortisol levels were positively related to cognitive impairment, and cortisol levels after dexamethasone treatment were related to cognitive decline. There was an inverse, but nonsignificant, association between DHEAS and cognitive impairment and decline.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
January/16/1997
Abstract
The relation between blood and cerebrospinal fluid (CSF) concentrations of cortisol, dehydroepiandrosterone (DHEA), and its sulfate (DHEAS) was measured in 62 subjects aged 3-85 yr old, fitted with ventriculo-peritoneal or lumbar-peritoneal shunts for a variety of diagnoses. There were 36 males and 36 females. Forty-eight subjects were not taking exogenous corticosteroids; the other 14 were receiving either systemic or local steroids. A single sample of blood and CSF was taken from each subject within 10 min for measurement of cortisol, DHEA, and DHEAS. The proportional levels of cortisol (5.8%) and DHEA (5.4%) in the CSF compared with those in the blood were similar in subjects not taking steroids. However, CSF DHEAS levels were only 0.15% of those in the blood. Because DHEAS blood levels were so much greater than DHEA, DHEAS in the CSF was still higher than DHEA despite the reduced penetration of the sulfated steroid. The blood/CSF ratios were similar in subjects taking steroids. There were significant correlations in steroid-free subjects between blood and CSF levels for DHEA (r = 0.65) and DHEAS (r = 0.88) but not for cortisol (r = 0.26). Steroid treatment significantly lowered blood cortisol, DHEA and DHEAS, and CSF DHEA, but not CSF cortisol or DHEAS compared with an age- and sex-matched sample of steroid-free subjects. In steroid-free adults (18 yr and over; n = 37), blood cortisol showed no age-related change. However, CSF cortisol was markedly raised in a proportion of steroid-free subjects over the age of 60 yr. Levels of corticoid-binding globulin in plasma did not alter with age. As expected, there were significant age-related decrements in both blood DHEA and DHEAS. CSF DHEA (r = 0.42) and CSF DHEAS (r = 0.39) were significantly negatively correlated with age. In steroid-free juveniles (n = 11) there were no age-related changes in either blood or CSF cortisol, but significant increases with age in DHEA and DHEAS in both blood and CSF. Calculation of the cortisol/DHEA and cortisol/ DHEAS molar ratios in the CSF showed both to be raised in the very young (3-8 yr) and the elderly (60 yr and over) by a factor of 4-5 compared with young adults aged 18-39. There were no sex differences in any of the parameters measured. These findings show that the relation between levels in the blood and CSF differ for each of these three neuroactive steroids. The brain is exposed to relatively high levels of DHEA and DHEAS during later childhood and early adulthood but to relatively or absolutely high levels of cortisol during infancy and older age. In view of the known antiglucocorticoid action of DHEA and DHEAS, and the direct action of these steroids on membrane-bound transmitter events (such as gamma-aminobutyric acidA receptors), these changes may have important implications for age-related alterations in brain function.
Publication
Journal: Biochemical Journal
February/13/1991
Abstract
The sulphation of bile acids is an important pathway for the detoxification and elimination of bile acids during cholestatic liver disease. A dehydroepiandrosterone (DHEA) sulphotransferase has been purified from male and female human liver cytosol using DEAE-Sepharose CL-6B and adenosine 3',5'-diphosphate-agarose affinity chromatography [Falany, Vazquez & Kalb (1989) Biochem. J. 260, 641-646]. Results in the present paper show that the DHEA sulphotransferase, purified to homogeneity, is also reactive towards bile acids, including lithocholic acid and 6-hydroxylated bile acids, as well as 3-hydroxylated short-chain bile acids. The highest activity towards bile acids was observed with lithocholic acid (54.3 +/- 3.6 nmol/min per mg of protein); of the substrates tested, the lowest activity was detected with hyodeoxycholic acid (4.2 +/- 0.01 nmol/min per mg of protein). The apparent Km values for the enzyme are 1.5 +/- 0.31 microM for lithocholic acid and 4.2 +/- 0.73 microM for taurolithocholic acid. Lithocholic acid also competitively inhibits DHEA sulphation by the purified sulphotransferase (Ki 1.4 microM). No evidence was found for the formation of bile acid sulphates by sulphotransferases different from the DHEA sulphotransferase during purification work. The above results suggest that a single steroid sulphotransferase with broad specificity encompassing neutral steroids and bile acids exists in human liver.
Publication
Journal: Cancer Research
January/24/1990
Abstract
A search of the literature using National Library of Medicine databases and individual cancer journal articles yielded over 500 compounds with published chemopreventive activity in animals. From these, an initial 16 agents or agent combinations have been evaluated in the following animal tumor models: mouse skin papillomas/carcinomas induced by 7,12-dimethylbenz(a)anthracene/12-O-tetradecanoylphorbol-13-acetate; rat breast adenocarcinoma induced by N-methyl-N-nitrosourea or 7,12-dimethylbenz(a)anthracene; hamster lung carcinoma induced by N-methyl-N-nitrosourea or diethylnitrosamine; mouse bladder papillary carcinoma induced by N-butyl-N-(4-hydroxybutyl)nitrosamine; and rat and mouse colon cancer induced by azoxymethane/methylazoxymethanol acetate. Some of the most interesting positive results observed include 4-hydroxyphenyl retinamide plus tamoxifen in breast cancer, piroxicam in colon cancer, dimethylfluoroornithine in breast and bladder cancer, oltipraz in lung cancer, dehydroepiandrosterone in colon cancer, and molybdate in bladder cancer. Eighteen human intervention trials in progress are described that involve the following agents: beta-carotene (eight trials). Retinol/retinoic acid (seven trials), vitamins C and E (three trials), 4-hydroxyphenyl retinamide (one trial), piroxicam (one trial), and calcium (one trial). By organ site these studies involve cancer of the lung (six studies), skin (five studies), colon (four studies), breast (one study), and uterine cervix (two studies).
Publication
Journal: Journal of Pharmacology and Experimental Therapeutics
September/29/2005
Abstract
Fetal liver CYP3A7 plays an important role in placental estriol synthesis during pregnancy, yet little is known concerning the extent or consequences of variability in expression. The purpose of this investigation was to characterize the variability in CYP3A7 expression using several phenotypic measures in a panel of 54 fetal livers ranging in age from 76 days to 32 weeks gestation. CYP3A7 mRNA expression was measured using quantitative polymerase chain reaction, whereas immunoreactive CYP3A7 was determined using an affinity-purified antipeptide antibody. Variability in catalytic activity was evaluated using testosterone and dehydroepiandrosterone (DHEA) as substrates. Across the entire panel, CYP3A7 was the most abundant CYP3A mRNA species present and varied 634-fold from 151 to 95,700 transcripts/ng total RNA, corrected for 18S ribosomal RNA. CYP3A4 expression was minimal based on mRNA expression (1000-fold lower than CYP3A7) and the ratio of testosterone 2alpha- (T2alphaH) to 6beta- (T6betaH) hydroxylation. T2alphaH and T6betaH were highly correlated (r(2) = 0.859), and the correlation increased (r(2) = 0.974) in livers with CYP3A5*3/*3 genotypes implying that the same enzyme (CYP3A7) generated both products. Overall, T2alphaH and DHEA16alphaH activities varied 175- and 250-fold, respectively. A subset of five samples had extremely low mRNA, protein, and catalytic activity, possibly due to pathology affecting fetal viability (anencephaly, porencephaly). In the remaining samples, T2alphaH activity varied 6.7-fold (358 +/- 142, range 97 to 643 pmol/min/mg) and DHEA16alphaH activity varied 6.2-fold (8.07 +/- 2.87, range 2.41 to 14.9 nmol/min/mg). Observed variability in CYP3A7 activity was not related to CYP3A7*2, and alternative regulatory mechanisms require further investigation.
Publication
Journal: Endocrinology
October/28/2003
Abstract
GATA-6 and GATA-4 are members of a family of transcription factors (GATA 1-6) that share conserved zinc-finger DNA binding domains. Using semiquantitative RT-PCR, we found that the human adrenal expresses mRNA for GATA-6 but not GATA-4. A recent study showed GATA-6 expression in the adrenal reticularis, the source of adrenal androgens. To investigate the role of GATA-6 in regulation of adrenal cell steroidogenesis, luciferase reporter constructs containing the 5'-flanking DNA from steroidogenic acute regulatory protein, cholesterol side-chain cleavage (CYP11A), 17alpha-hydroxylase (CYP17), and dehydroepiandrosterone-sulfotransferase (SULT2A1) were cotransfected with an expression vector containing GATA-6 into adrenal NCI-H295R cells and nonsteroidogenic HEK293 cells. All promoter/reporter constructs were increased by GATA-6 in the adrenal model. However, in the HEK293 cells only SULT2A1 reporter activity was increased by GATA-6. One key difference between H295R and HEK293 cell lines is the differential expression of steroidogenic factor 1 (SF1). Transfection of HEK293 cells with both GATA-6 and SF1 significantly increased transcriptional activation of all reporter constructs above the effect of GATA-6 or SF1 alone. To determine whether the action of GATA-6 required SF1, we transfected HEK293 cells with each promoter construct plus and minus GATA-6, SF1, and/or the orphan nuclear repressor DAX1. DAX1 opposed SF1-activated transcription of many genes and abolished the GATA-6/SF1 ability to increase reporter activity. These results suggest that the adrenal uses GATA-6 to enhance transcription of steroid-metabolizing enzymes needed to produce dehydroepiandrosterone sulfate. Additionally, GATA-6 works in synergy with SF1 to maximally increase expression of enzymes needed to produce adrenal androgens.
Publication
Journal: American Journal of Obstetrics and Gynecology
February/22/1999
Abstract
OBJECTIVE
The purpose of the study was to determine whether maternal serum levels of androgens, especially testosterone, are higher in patients with preeclampsia than in matched normotensive control subjects.
METHODS
Serum testosterone, dehydroepiandrosterone sulfate, sex hormone binding globulin, and estradiol levels were measured in 16 subjects in the third trimester of pregnancy with documented preeclampsia and 26 healthy, normotensive women with similar maternal and gestational ages. All subjects were primigravid women with singleton pregnancies who were seen in the labor and delivery department at North Oakland Medical Centers in Pontiac, Mich.
RESULTS
Total testosterone and free testosterone levels were significantly higher in patients with preeclampsia (213.6 +/- 25.9 ng/dL and 0.5 +/- 0.1 ng/dL, respectively) than in the control group (154.5 +/- 14.8 ng/dL and 0. 3 +/- 0.03 ng/dL, respectively). There were no significant differences in sex hormone binding globulin, dehydroepiandrosterone sulfate, and estradiol concentrations. There were also no significant differences in maternal age, gestational age, body mass index, and neonatal sex.
CONCLUSIONS
Levels of the potent androgen testosterone were significantly higher in primigravid women with preeclampsia than in normotensive women with similar gestational and maternal ages. This difference may indicate a role for testosterone in the pathogenesis of preeclampsia.
Publication
Journal: Journal of Endocrinology
August/13/1997
Abstract
Dehydroepiandrosterone sulphate (DHEAS) and unconjugated dehydroepiandrosterone (DHEA) have been determined in the blood serum of normal subjects of both sexes from 1 month to 100 years of age. In total, 92 girls, 49 boys, 211 women and 110 men were investigated. The effects of age and sex on the levels of the hormones were measured. DHEAS levels declined rapidly during the first year of life and were maintained at a minimum level for 5 years. They increased significantly from 6 to 7 years of age and reached maximum levels in women at about 24 years and in men at about 30 years of age. They then declined rapidly in both sexes but the fall which occurred after 50 and 60 years of age respectively was only moderate. Age-related unconjugated DHEA levels were different. After the first month of life DHEA levels were relatively high and declined more slowly. The minimum level was observed in girls between 5 and 7 years and in boys between 5 and 9 years of age. A significant rise then began and levels reached a maximum in women as well as in men at about 20 years of age. In men levels then declined up to the age of 80. In women the DHEA levels declined during the next 15 years and from approximately 36 years of age they again rose significantly up to a second peak. A mild but significant decline then resumed. There was a difference in the levels of DHEA and DHEAS depending on sex. Unlike DHEAS, unconjugated DHEA was higher in women than in men. However, this difference was significant only in some age groups: during puberty (between 11 and 15 years of age), in the premenopausal period (between 36 and 45 years of age) and in the older group (after 60 years of age). Age- and sex-related dependencies were different between DHEAS and DHEA. They indicate the possible variable secretion and dynamics of their (inter)conversion. We have concluded that DHEA measurements cannot be a substitute for DHEAS and vice versa.
Publication
Journal: Clinical Cancer Research
June/23/2008
Abstract
OBJECTIVE
Cancer diagnosis and treatment imparts chronic stressors affecting quality of life (QOL) and basic physiology. However, the capacity to increase survival by improving QOL is controversial. Patients with cervical cancer, in particular, have severely compromised QOL, providing a population well-suited for the evaluation of novel psychosocial interventions and the exploration of mechanisms by which modulation of the psychoneuroimmune axis might result in improved clinical outcomes.
METHODS
A randomized clinical trial was conducted in cervical cancer survivors that were enrolled at>>or=13 and <22 months after diagnosis (n=50), comparing a unique psychosocial telephone counseling (PTC) intervention to usual care. QOL and biological specimens (saliva and blood) were collected at baseline and 4 months post-enrollment.
RESULTS
The PTC intervention yielded significantly improved QOL (P=0.011). Changes in QOL were significantly associated with a shift of immune system T helper type 1 and 2 (Th1/Th2) bias, as measured by IFN-gamma/interleukin-5 ELISpot T lymphocyte precursor frequency; improved QOL being associated with increased Th1 bias (P=0.012). Serum interleukin-10 and the neuroendocrine variables of cortisol and dehydroepiandrosterone revealed trends supporting this shift in immunologic stance and suggested a PTC-mediated decrease of the subject's chronic stress response.
CONCLUSIONS
This study documents the utility of a unique PTC intervention and an association between changes in QOL and adaptive immunity (T helper class). These data support the integration of the chronic stress response into biobehavioral models of cancer survivorship and suggests a novel mechanistic hypotheses by which interventions leading to enhanced QOL could result in improved clinical outcome including survival.
Publication
Journal: Acta Psychiatrica Scandinavica
January/8/2007
Abstract
OBJECTIVE
Increased plasma dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEAS) have been demonstrated in post-traumatic stress disorder (PTSD), but the documented beneficial effects of these steroids in enhancing mood and cognition, as well as neuroprotection, suggest their presence in PTSD may be associated with defensive rather than maladaptive effects.
METHODS
We, therefore, examined plasma DHEA, DHEAS, cortisol, and the DHEA/cortisol ratio in 40 male veterans with or without PTSD, and determined their relationships to PTSD symptom severity and symptom improvement.
RESULTS
The PTSD group showed significantly higher plasma DHEA and non-significantly higher DHEAS levels as well as a significantly lower cortisol/DHEA ratio, controlling for age. Regression analyses demonstrated that DHEA and DHEAS levels could be predicted by symptom improvement and coping, whereas the cortisol/DHEA ratio was predicted by severity of childhood trauma and current symptom severity.
CONCLUSIONS
That greater symptom improvement was related to DHEA levels may suggest for a role for these hormones in modulating recovery from PTSD.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
April/1/1991
Abstract
A description is presented of the first documented case of placental aromatase deficiency. The deficiency caused maternal virilization during pregnancy and pseudohermaphroditism of the female fetus. A 24-yr-old primigravida showed progressive virilization during the third trimester. Urinary excretion of estrogen was less than 14 mumol/day between 35-38 weeks of pregnancy, although nonstress tests showed reactive patterns and serum levels of human placental lactogen were above 460 nmol/L. Maternal serum levels of estrogens were low, and those of androgens were high in the third trimester. A dehydroepiandrosterone sulfate loading test induced a marked increase in maternal serum levels of androgens, whereas no such increase was observed in estrogens. The woman delivered vaginally a live full-term infant who exhibited female pseudohermaphroditism. Cord serum levels of estrogens were extremely low, while those of androgens were high. The aromatase activity of the placenta, determined by the conversion of [7-3H]androstenedione to 17 beta-[7-3H]estradiol and [7-3H]estrone, were less than 0.03 fmol/microgram protein.min (control, 9.6 +/- 2.2 fmol/microgram protein.min). The sulfatase activity of the placenta was 0.63 pmol/microgram protein.min compared to 0.46 +/- 0.16 pmol/microgram protein.min in controls. The rate of aromatization by normal control placentas was the same as that obtained during coincubation of samples of normal placentas and that of the patient. Thus, the presence of aromatase inhibitor in the patient's placenta was excluded.
Publication
Journal: Journal of Pharmacology and Experimental Therapeutics
April/12/2005
Abstract
Breast cancer resistance protein (Bcrp/Abcg2) is a new efflux transporter found at the blood-brain barrier (BBB) of humans and pigs. Since it has been hypothesized that Bcrp may act as a new type of efflux transporter at the BBB, we investigated the involvement of Bcrp in the efflux transport of typical substrates, dehydroepiandrosterone sulfate (DHEAS) and mitoxantrone, across the mouse BBB. The expression of Bcrp in mouse brain capillaries was confirmed by quantitative polymerase chain reaction, Western blot, and immunohistochemical analysis. The role of Bcrp as an efflux transporter was evaluated using the in situ brain perfusion method in wild-type and P-glycoprotein (P-gp) knockout mice with or without treatment with GF120918 (Elacridar), an inhibitor of both Bcrp and P-gp. The increased brain uptake of [(3)H]DHEAS and [(3)H]mitoxantrone by GF120918 in wild-type and P-gp knockout mice suggested the existence of a GF120918-sensitive and P-gp-independent efflux transporter for DHEAS and mitoxantrone across the BBB. However, the brain uptake of [(3)H]DHEAS in Bcrp knockout mice was comparable with that in wild-type mice, and the effect of GF120918 was still observed in Bcrp knockout mice. In addition, the brain uptake of [(3)H]mitoxantrone was also similar in wild-type and Bcrp knockout mice. These results suggest that although BCRP is expressed at the BBB it plays a minor role in active efflux transport of DHEAS and mitoxantrone out of brain and that one or more GF120918-sensitive efflux transporters distinct from BCRP or P-gp contributes to the brain efflux of DHEAS and mitoxantrone.
Publication
Journal: Endocrinology
January/10/2007
Abstract
Oxidative stress plays a key role in the pathogenesis of diabetic cardiomyopathy, which is characterized by myocyte loss and fibrosis, finally resulting in heart failure. The study looked at the downstream signaling whereby oxidative stress leads to reduced myocardial contractility in the left ventricle of diabetic rats and the effects of dehydroepiandrosterone (DHEA), which production is suppressed in the failing heart and prevents the oxidative damage induced by hyperglycemia in several experimental models. DHEA was given orally at a dose of 4 mg/rat per day for 21 d to rats with streptozotocin (STZ)-induced diabetes and genetic diabetic-fatty (ZDF) rats. Oxidative balance, advanced glycated end products (AGEs) and AGE receptors, cardiac myogenic factors, and myosin heavy-chain gene expression were determined in the left ventricle of treated and untreated STZ-diabetic rats and ZDF rats. Oxidative stress induced by chronic hyperglycemia increased AGE and AGE receptors and led to activation of the pleoitropic transcription factor nuclear factor-kappaB. Nuclear factor-kappaB activation triggered a cascade of signaling, which finally led to the switch in the cardiac myosin heavy-chain (MHC) gene expression from the alpha-MHC isoform to the beta-MHC isoform. DHEA treatment, by preventing the activation of the oxidative pathways induced by hyperglycemia, counteracted the enhanced AGE receptor activation in the heart of STZ-diabetic rats and ZDF rats and normalized downstream signaling, thus avoiding impairment of the cardiac myogenic factors, heart autonomic nervous system and neural crest derivatives (HAND) and myogenic enhancer factor-2, and the switch in MHC gene expression, which are the early events in diabetic cardiomyopathy.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
May/13/2009
Abstract
Adrenal insufficiency, primarily presenting as an adrenal crisis, is a life-threatening emergency and requires prompt therapeutic management including fluid resuscitation and stress dose hydrocortisone administration. Primary adrenal insufficiency is most frequently caused by autoimmune adrenalitis, and hypothalamic-pituitary tumors represent the most frequent cause of secondary adrenal insufficiency. However, the exact underlying diagnosis needs to be confirmed by a stepwise diagnostic approach, with an open eye for other differential diagnostic possibilities. Chronic replacement therapy with glucocorticoids and, in primary adrenal insufficiency, mineralocorticoids requires careful monitoring. However, current replacement strategies still require optimization as evidenced by recent studies demonstrating significantly impaired subjective health status and increased mortality in patients with primary and secondary adrenal insufficiency. Future studies will have to explore the potential of dehydroepiandrosterone replacement and modified delayed-release hydrocortisone to improve the prospects of patients with adrenal insufficiency.
load more...