Effect of ACTH and prolactin on dehydroepiandrosterone, its sulfate ester and cortisol production by normal and tumorous human adrenocortical cells

The effect of ACTH and prolactin on the synthesis of dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) was studied in cell suspensions of "normal" and tumorous (adenoma) human adrenal cortex. A stimulation of DHEA and no response of DHEAS production by ACTH in "normal" adrenocortical cell suspension was observed. However ACTH stimulated both DHEA and DHEAS synthesis in tumorous adrenocortical cells. Prolactin did not influence either the basal or the ACTH stimulated DHEA and DHEAS production of adrenocortical cells irrespective of their origin. Our results are compatible with the concept that the biosynthesis of DHEA is under ACTH control, while other factor(s) regulate(s) the sulfate pathway of DHEA secretion under normal conditions. In tumorous adrenocortical cells DHEA may be regulated--at least partly--by ACTH. Prolactin seems to have no direct effect on DHEA and DHEAS synthesis. It is postulated that the relationship between serum prolactin and DHEAS (or DHEA) levels observed by several authors might be an extraadrenal effect of prolactin on adrenal androgens.     

Characterization of serum dehydroepiandrosterone secretion in golden hamsters

Dehydroepiandrosterone (DHEA) is an adrenal androgen whose function is poorly understood. Although DHEA and DHEA sulfate (DHEAS) are secreted in relatively high quantities by the human adrenal, the laboratory rat secretes very little, thus hindering experimental studies of the hormone. In this paper, we measured the changes in serum DHEA and DHEAS under various physiological conditions in golden hamsters. Evening serum DHEAS fell from 6.30 +/- 0.78 microg/dl (mean +/- SE) before surgery to 3.03 +/- 0.23 microg/dl 12 days after bilateral adrenalectomy. Hamsters had higher levels of DHEA and DHEAS in the evening than in the morning, but removal of the gonads did not consistently decrease serum DHEA or DHEAS in males or females. Evening levels of DHEA and DHEAS reached a peak around 7 weeks of age and then gradually decreased to about one-third of these levels by one year of age. These results suggest that DHEA and DHEAS are secreted at least in part from the hamster adrenal, that they do not originate from the gonads, and that there is a daily rhythm with peak levels at a time of day just preceding the active phase. In addition, the levels of these hormones decrease with aging.     

Steroid sulfatase (STS) expression in the human temporal lobe: enzyme activity, mRNA expression and immunohistochemistry study

Dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) are suggested to be important neurosteroids. We investigated steroid sulfatase (STS) in human temporal lobe biopsies in the context of possible cerebral DHEA(S) de novo biosynthesis. Formation of DHEA(S) in mature human brain tissue has not yet been studied. 17 alpha-Hydroxylase/C17-20-lyase and hydroxysteroid sulfotransferase catalyze the formation of DHEA from pregnenolone and the subsequent sulfoconjugation, respectively. Neither their mRNA nor activity were detected, indicating that DHEA(S) are not produced within the human temporal lobe. Conversely, strong activity and mRNA expression of DHEAS desulfating STS was found, twice as high in cerebral neocortex than in subcortical white matter. Cerebral STS resembled the characteristics of the known placental enzyme. Immunohistochemistry revealed STS in adult cortical neurons as well as in fetal and adult Cajal-Retzius cells. Organic anion transporting proteins OATP-A, -B, -D, and -E showed high mRNA expression levels with distinct patterns in cerebral neocortex and subcortical white matter. Although it is not clear whether they are expressed at the blood-brain barrier and facilitate an influx rather than an efflux, they might well be involved in the transport of steroid sulfates from the blood. Therefore, we hypothesize that DHEAS and/or other sulfated 3beta-hydroxysteroids might enter the human temporal lobe from the circulation where they would be readily converted via neuronal STS activity.     

Do DHEA/DHEAS play a protective role in coronary heart disease?

Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEAS), the major androgens secreted by human adrenal glands, were suggested to play a protective role in the pathogenesis of atherosclerosis and coronary heart disease. On the basis of a critical review of all existing studies we concluded that 1) there is no evidence of a protective role of DHEA and DHEAS in women, and 2) men with low plasma DHEA and DHEAS levels can be considered as beings at risk of developing a fatal cardiovascular event. These androgens can interfere with atherogenic process by several mechanisms. They influence enzymes such as glucoso-6-phosphate dehydrogenase, which can modify the lipid spectrum. Furthermore, they can inhibit human platelet aggregation, enhance fibrinolysis, slow down cell proliferation and reduce plasma levels of plasminogen activator inhibitor type 1 and tissue plasminogen activator antigen. We suggest that all these DHEA(S) actions are dependent on sex hormone metabolic pathways. There are still insufficient data to advise DHEA supplementation in elderly men, but this type of hormone replacement therapy merits further studies.     

Effects of gemfibrozil treatment on serum levels of androstanediol glucuronide and adrenal androgens.

We have prospectively investigated the role of adrenal cortical androgens as a risk factor for coronary heart disease in the Helsinki Heart Study population. Simultaneously we studied the effects of gemfibrozil treatment on the serum levels of dehydroepiandrosterone (DHEA), its sulfate (DHEAS), and their metabolite androstanediol glucuronide (3 alpha AdiolG) with those of placebo. Gemfibrozil (n = 133) vs placebo (n = 159) treatment was associated with significant elevation of mean (SD) DHEAS (mumol/l) 8.35 (5.31) vs 6.98 (3.85); P less than 0.02, and of 3 alpha AdiolG (nmol/l) 17.45 (7.57) vs 8.62 (3.56); P less than 0.001), and of almost significant elevation of DHEA (nmol/l) 10.12 (6.64) vs 8.78 (5.86); P less than 0.07). These new observations suggest that gemfibrozil treatment increases the production and turnover of DHEA and DHEAS and may in addition stimulate the 5 alpha-reduction of androgens.     

Changes in the incorporation of labelled amino acids into proteins and homogenates of the brains of rats that have suffered acute hypoxia in the antenatal period]

The authors studied C14-leucine and S35-methionine incorporation into the brain tissue homogenates and protein from different parts of the brain of rats subjected to intrauterine hypoxia. Depression of protein synthesis in certain brain structures, particularly in the hyppocampus was observed alongside with the stimulation of the amino acid incorporation into proteins of the other parts of the brain. Changes of the amino acid penetration into tissue homogenates fialed to correlate with the rate of their incorporation into proteins in separate structures of the brain. Experimental results pointed to disfunction in the protein metabolism intensity and in the blood-brain barrier system occurring during the late ontogenesis in rats surviving the intrauterine hypoxia.     

Measurement of serum levels of dehydroepiandrosterone sulfate: a comparison of radioimmunoassay and enzymatic analysis

Dehydroepiandrosterone sulfate (DHEAS) and unconjugated dehydroepiandrosterone (DHEA) are secretory products of the adrenal cortex. Measurement of serum levels of these steroids is of increasing epidemiologic interest, since low serum concentrations of DHEAS or DHEA have been associated with an increased risk of dying of cardiovascular disease or of developing cancer. Radioimmunoassays (RIAs) are the most convenient systems for the measurement of serum DHEAS concentrations in multiple samples. However, using sera from four individuals we show that different RIA kits provide quite different estimates of serum DHEAS concentrations. Moreover, these results do not always agree with the serum concentrations determined by an independent chromatographic and enzymatic reference method. The results highlight the need for an independent method of determining DHEAS levels in sera that can provide guidance in selecting an appropriate RIA, and in interpreting the results.     

Simplified procedure for measurement of serum dehydroepiandrosterone and its sulfate with gas chromatography–ion trap mass spectrometry and selected reaction monitoring

Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) are endogenous steroids that have recently been widely publicized as potential treatments for many disorders. This paper describes a gas chromatographic–ion trap mass spectrophotometric assay with selected reaction monitoring for measurement of DHEA and DHEAS levels. The hormones and internal standard (5-androsten-3β-ol-16-one methyl ester) are extracted from serum with Oasis solid-phase extraction tubes. The extracted steroids are dissolved in methanol and injected into a Finnigan GCQ ion trap mass spectrometer. In the selected reaction mode, both DHEA and DHEAS can be identified and quantified in a single injection. No derivatization or expensive deuterated internal standards are required.     

Antioxidant activity of dioscorea and dehydroepiandrosterone (DHEA) in older humans

Dioscorea is a yam steroid extract used in commercial steroid synthesis and consumed by people. DHEA is a steroid which declines with age, but without known activity. This study was designed to determine whether dioscorea supplementation could increase serum dehydroepiandrosterone sulfate (DHEAS) in humans and modulate lipid levels in older people. The subjects were selected volunteers aged 65–82 years. The serum DHEAS level, lipid peroxidation and lipid profile were assessed. Three weeks of dioscorea supplementation had no affect on serum DHEAS level. However DHEA intake of 85 mg/day increased serum DHEA levels 100.3 %. DHEA and dioscorea significantly reduced serum lipid peroxidation, lowered serum triglycerides, phospholipid and increased HDL levels. Both DHEA and the steroid yam extract, dioscorea, have significant activities as antioxidant to modify serum lipid levels.     

Steroid metabolism and profile of steroidogenic gene expression in Episkin: high similarity with human epidermis

The skin is a well-recognized site of steroid formation and metabolism. Episkin is a cultured human epidermis. In this report, we investigate whether Episkin possesses a steroidogenic machinery able to metabolize adrenal steroid precursors into active steroids. Episkin was incubated with [14C]-dehydroepiandrosterone (DHEA) and 4-androstenedione (4-dione) and their metabolites were analyzed by liquid chromatography/mass spectrometry (LC/MS/MS). The results show that the major product of DHEA metabolism in Episkin is DHEA sulfate (DHEAS) (88% of the metabolites) while the other metabolites are 7alpha-OH-DHEA (8.2%), 4-dione (1.3%), 5-androstenediol (1.3%), dihydrotestosterone (DHT) (1.4%) and androsterone (ADT) (2.3%). When 4-dione is used as substrate, much higher levels of C19-steroids are produced with ADT representing 77% of the metabolites. These data indicate that 5alpha-reductase, 17beta-hydroxysteroid dehydrogenase (17beta-HSD) and 3alpha-hydroxysteroid dehdyrogenase (3alpha-HSD) activities are present at moderate levels in Episkin, while 3beta-HSD activity is low and represents a rate-limiting step in the conversion of DHEA into C19-steroids. Using realtime PCR, we have measured the level of mRNAs encoding the steroidogenic enzymes in Episkin. A good agreement is found between the mRNAs expression in Episkin and the metabolic profile. High expression levels of steroid sulfotransferase SULT2B1B and type 3 3alpha-HSD (AKR1C2) correspond to the high levels of DHEA sulfate (DHEAS) and ADT formed from DHEA and 4-dione, respectively. 3beta-HSD is almost undetectable while the other enzymes such as type 1 5alpha-reductase, types 2, 4, 5, 7, 8, and 10 17beta-HSD and 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) (AKR1C1) are highly expressed. Except for UGT-glucuronosyl transferase, similar mRNA expression profiles between Episkin and human epidermis are observed.     

Sex differences due to dehydroepiandrosterone (DHEA) feeding affecting dehydroepiandrosterone sulfate secretion in golden Syrian hamsters.

The metabolism of orally administered dehydroepiandrosterone (DHEA) by male and female golden Syrian hamsters was examined by quantification of DHEA and dehydroepiandrosterone sulfate (DHEAS) in gallbladder bile, urine and feces using high-performance liquid chromatography (HPLC). Plasma levels of DHEA and DHEAS were also determined by radioimmunoassay (RIA). After 5 days of oral DHEA administration (100 mg/kg body weight twice a day), RIA showed that plasma levels of DHEA and DHEAS were increased approximately 3-6 and 4-5 times, respectively, compared to controls. More than 95 % of circulating DHEA (S) in the peripheral blood was DHEAS. There was no significant sex difference in DHEAS plasma levels between male and female animals in the DHEA-supplemented group. However, 0.2 - 0.3 % of ingested DHEA was conjugated to DHEAS and excreted in urine by females, whereas less than 0.002 % was excreted in urine by males (p < 0.005). DHEAS was excreted in bile by males after DHEA supplementation, and the sex differences in DHEAS levels observed in bile were statistically significant (male, 18.7 +/- 7.5 vs. female, 5.6 +/- 3.1 micromol/l) (p < 0.005). Small amounts of ingested DHEA were excreted in an unchanged state in feces, and no sex difference was observed. These results suggest that there is a considerable sex difference in the conjugation and excretion of orally administered DHEA in the hamster.     

Adrenal androgen concentrations increase during infancy in male rhesus macaques (Macaca mulatta)

This study investigated adrenal androgens (AA), gonadotropins, and cortisol in castrated and gonad-intact male rhesus macaques from birth through infancy. Blood samples were collected longitudinally from castrated (n = 6; weekly, 1-40 wk) and intact (n = 4; every other week, 1-17 wk) males. Plasma concentrations of AA were determined by liquid chromatography-tandem mass spectrometry, and plasma concentrations of cortisol and gonadotropins were determined by RIA. Dehydroepiandrosterone sulfate (DHEAS) concentrations increased almost threefold (to 8 wk), dehydroepiandrosterone (DHEA) increased more than eightfold (to 11 wk), and androstenedione doubled (to 15 wk) in five castrated infant males and declined continuously thereafter. A sixth castrated male had markedly different temporal patterns and concentrations (many times more than 2 SDs from the cohort mean) of AA and gonadotropins from first sampling (3 wk) and was excluded from analysis. Cortisol increased over 16 wk but correlated poorly with DHEAS. Luteinizing and follicle-stimulating hormones increased to peaks at 3 and 7 wk, respectively. Testis-intact males exhibited similar profiles, but with earlier peaks of DHEAS (5 wk) and DHEA and androstenedione (7 wk). Peak concentrations of DHEAS were lower and those of DHEA and androstenedione were higher in intact than castrated infants. Testosterone was undetectable in castrated males and >0.5 ng/ml in intact males but was not correlated with DHEA or DHEAS. These are the first data documenting a transient increase in AA secretion during infancy in an Old World primate and are consistent with the previously documented time course of zona reticularis development that accompanies increases in androgen synthetic capacity of the adrenal. The rhesus is a promising model for androgen secretion from the human adrenal cortex.     

Dehydroepiandrosterone inhibits lipopolysaccharide-induced nitric oxide production in BV-2 microglia

Levels of dehydroepiandrosterone (DHEA) and its sulfated derivative (DHEAS) decline during aging and reach even lower levels in Alzheimer's disease (AD). DHEA is known to exhibit a variety of functional activities in the CNS, including an increase of memory and learning, neurotrophic and neuroprotective effects, and the reduction of risk of age-related neurodegenerative disorders. However, the influence of DHEA on the immune functions of glial cells is poorly understood. In this study, we investigated the effect of DHEA on activated glia. The production of inducible nitric oxide synthase (iNOS) was studied in lipopolysaccharide (LPS)-stimulated BV-2 microglia, as a model of glial activation. The results showed that DHEA but not DHEAS significantly inhibited the production of nitrite in the LPS-stimulated BV-2 cell cultures. Pretreatment of BV-2 cells with DHEA reduced the LPS-induced iNOS mRNA and protein levels in a dose-dependent manner. The LPS-induced iNOS activity in BV-2 cells was decreased by the exposure of 100 microM DHEA. Moreover, DHEA suppressed iNOS gene expression in LPS-stimulated BV-2 cells did not require de novo synthesis of new proteins or destabilize of iNOS mRNA. Since DHEA is biosynthesized by astrocytes and neurons, our findings suggest that it might have an important regulatory function on microglia.     

Steroid sulfatase inhibitors: promising new tools for breast cancer therapy?

Inhibition of aromatase is currently well-established as the major treatment option of hormone-dependent breast cancer in postmenopausal women. However, despite the effects of aromatase inhibitors in both early and metastatic breast cancer, endocrine resistance may cause relapses of the disease and progression of metastasis. Thus, driven by the success of manipulating the steroidogenic enzyme aromatase, several alternative enzymes involved in steroid synthesis and metabolism have recently been investigated as possible drug targets. One of the most promising targets is the steroid sulfatase (STS) which converts steroid sulfates like estrone sulfate (E1S) and dehydroepiandrosterone sulfate (DHEAS) to estrone (E1) and dehydroepiandrosterone (DHEA), respectively. Estrone and DHEA may thereafter be used for the synthesis of more potent estrogens and androgens that may eventually fuel hormone-sensitive breast cancer cells. The present review summarizes the biology behind steroid sulfatase and its inhibition, the currently available information derived from basic and early clinical trials in breast cancer patients, as well as ongoing research. Article from the Special Issue on Targeted Inhibitors.     

Adrenal androgen production in catarrhine primates and the evolution of adrenarche

Adrenarche is a developmental event involving differentiation of the adrenal gland and production of adrenal androgens, and has been hypothesized to play a role in the extension of the preadolescent phase of human ontogeny. It remains unclear whether any nonhuman primate species shows a similar suite of endocrine, biochemical, and morphological changes as are encompassed by human adrenarche. Here, we report serum concentrations of the adrenal androgens dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) measured in 698 cross-sectional and mixed longitudinal serum samples from catarrhine primates ranging from 0.6 to 47 years of age. DHEAS in Pan is most similar to that of humans in both age-related pattern and absolute levels, and a transient early increase appears to be present in Gorilla. DHEA levels are highest in Cercocebus, Cercopithecus, and Macaca. We also tested for evidence of adaptive evolution in six genes that code for proteins involved in DHEA/S synthesis. Our genetic analyses demonstrate the protein-coding regions of these genes are highly conserved among sampled primates. We describe a tandem gene duplication event probably mediated by a retrotransposon that resulted in two 3-β-hydroxysteroid dehydrogenase/Delta 5-Delta 4 genes (HSD3B1 and HSD3B2) with tissue specific functions in catarrhines. In humans, HSD3B2 is expressed primarily in the adrenals, ovary, and testis, while HSD3B1 is expressed in the placenta. Taken together, our findings suggest that while adrenarche has been suggested to be unique to hominoids, the evolutionary roots for this developmental stage are more ancient.     

Deletion of the mouse P450c17 gene causes early embryonic lethality

Dehydroepiandrosterone (DHEA), a 19-carbon precursor of sex steroids, is abundantly produced in the human but not the mouse adrenal. However, mice produce DHEA and DHEA-sulfate (DHEAS) in the fetal brain. DHEA stimulates axonal growth from specific populations of mouse neocortical neurons in vitro, while DHEAS stimulates dendritic growth from those cells. The synthesis of DHEA and sex steroids, but not mouse glucocorticoids and mineralocorticoids, requires P450c17, which catalyzes both 17 alpha-hydroxylase and 17,20-lyase activities. We hypothesized that P450c17-knockout mice would have disordered sex steroid synthesis and disordered brain DHEA production and thus provide phenotypic clues about the functions of DHEA in mouse brain development. We deleted the mouse P450c17 gene in 127/SvJ mice and obtained several lines of mice from two lines of targeted embryonic stem cells. Heterozygotes were phenotypically and reproductively normal, but in all mouse lines, P450c17(-/-) zygotes died by embryonic day 7, prior to gastrulation. The cause of this early lethality is unknown, as there is no known function of fetal steroids at embryonic day 7. Immunocytochemistry identified P450c17 in embryonic endoderm in E7 wild-type and heterozygous embryos, but its function in these cells is unknown. Enzyme assays of wild-type embryos showed a rapid rise in 17-hydroxylase activity between E6 and E7 and the presence of C(17,20)-lyase activity at E7. Treatment of pregnant females with subcutaneous pellets releasing DHEA or 17-OH pregnenolone at a constant rate failed to rescue P450c17(-/-) fetuses. Treatment of normal pregnant females with pellets releasing pregnenolone or progesterone did not cause fetal demise. These data suggest that steroid products of P450c17 have heretofore-unknown essential functions in early embryonic mouse development.     

Skeletal muscle differentiation: role of dehydroepiandrosterone sulfate

Dehydroepiandrosterone (DHEA) and its sulfonated form dehydroepiandrosterone sulfate (DHEAS) are the main circulating steroid hormones and many epidemiological studies show an inverse relationship between DHEA/DHEAS levels and muscle loss for which the primary cause is the accelerated protein breakdown. The aim of this work was to determine whether DHEA/DHEAS supplementation in differentiating C2C12 skeletal muscle cells might influence the expression of the atrophy-related ubiquitin ligase, MuRF-1, and thereby impact key molecules of the differentiation program. DHEA is the prohormone crucial for sex steroid synthesis, and DHEAS is thought to be its reservoir. However, our preliminary experiments showed that DHEAS, but not DHEA, is able to influence MuRF-1 expression. Therefore, we treated differentiating C2C12 cells with various concentrations of DHEAS and analyzed the expression of MuRF-1, Hsp70, myosin heavy chain (MHC), myogenin, and the activity of creatine kinase. We observed that DHEAS at physiological concentrations downregulates MuRF-1 expression and affects muscle differentiation, as shown by the increased levels of MHC, which is a sarcomeric protein that undergoes MuRF-1-dependent degradation, and also by an increase in creatine kinase activity and myogenin expression, which are two other well-known markers of differentiation. Moreover, we found that DHEAS might have a protective effect on differentiating cells as suggested by the augmented levels of Hsp70, a member of heat shock proteins family that, besides its cytoprotective action, seems to have a regulatory role on key atrophy genes such as MuRF-1. In conclusion, our data shed light on the role of DHEAS at physiologic concentrations in maintaining muscle mass.     

Is dehydroepiandrosterone sulfate an anxiolytic agent?

Effects of dehydroepiandrosterone sulfate (DHEAS, 30 mg/kg, i.p., 4 and 28 hours after the injection) were studied in CBA/Lac male mice different in the level of anxiety resulting from repeated social victories (winners) or social defeats (losers) in 10 daily agonistic confrontations. The losers demonstrated high level of anxiety estimated by the "partition" test. The DHEAS and saline injections had different effects on winners, losers, and intact mice. DHEAS prevented the development of anxiety in losers 28 hours after the injection. In these experimental conditions DHEAS exerted no effect on winners. It was concluded that the DHEAS effect depends on the psychoemotional state of an animal. The anxiolytic effect of the exogenous DHEAS may be also characteristic of the endogenous hormone secreted by the adrenal glands and in the central nervous system.     

Steroid sulfatase inhibitor DU-14 protects spatial memory and synaptic plasticity from disruption by amyloid β protein in male rats

Alzheimer's disease (AD) is an age-related mental disorder characterized by progressive loss of memory and multiple cognitive impairments. The overproduction and aggregation of Amyloid β protein (Aβ) in the brain, especially in the hippocampus, are closely involved in the memory loss in the patients with AD. Accumulating evidence indicates that the Aβ-induced imbalance of dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS) in the brain plays an important role in the AD pathogenesis and progression. The level of DHEA is elevated, while DHEAS is dramatically decreased in the AD brain. The present study tried to restore the balance between DHEA and DHEAS by using a non-steroidal sulfatase inhibitor DU-14, which increases endogenous DHEAS through preventing DHEAS converted back into DHEA. We found that: (1) DU-14 effectively attenuated the Aβ_1–42-induced cognitive deficits in spatial learning and memory of rats in Morris water maze test; (2) DU-14 prevented Aβ_1–42-induced decrease in the cholinergic theta rhythm of hippocampal local field potential (LFP) in the CA1 region; (3) DU-14 protected hippocampal synaptic plasticity against Aβ_1–42-induced suppression of long term potentiation (LTP). These results provide evidence for the neuroprotective action of DU-14 against neurotoxic Aβ, suggesting that up-regulation of endogenous DHEAS by DU-14 could be beneficial to the alleviation of Aβ-induced impairments in spatial memory and synaptic plasticity.