A review of dehydroepiandrosterone (DHEA)

Anterior pituitary, sex hormones, and keratoconus: Beyond traditional targets

"The Diseases of the Horny-coat of The Eye", known today as keratoconus, is a progressive, multifactorial, non-inflammatory ectatic corneal disorder that is characterized by steepening (bulging) and thinning of the cornea, irregular astigmatism, myopia, and scarring that can cause devastating vision loss. The significant socioeconomic impact of the disease is immeasurable, as patients with keratoconus can have difficulties securing certain jobs or even joining the military. Despite the introduction of corneal crosslinking and improvements in scleral contact lens designs, corneal transplants remain the main surgical intervention for treating keratoconus refractory to medical therapy and visual rehabilitation. To-date, the etiology and pathogenesis of keratoconus remains unclear. Research studies have increased exponentially over the years, highlighting the clinical significance and international interest in this disease. Hormonal imbalances have been linked to keratoconus, both clinically and experimentally, with both sexes affected. However, it is unclear how (molecular/cellular signaling) or when (age/disease stage(s)) those hormones affect the keratoconic cornea. Previous studies have categorized the human cornea as an extragonadal tissue, showing modulation of the gonadotropins, specifically luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Studies herein provide new data (both in vitro and in vivo) to further delineate the role of hormones/gonadotropins in the keratoconus pathobiology, and propose the existence of a new axis named the Hypothalamic-Pituitary-Adrenal-Corneal (HPAC) axis.

Through the Looking-Glass: Reevaluating DHEA Metabolism Through HSD3B1 Genetics

Dehydroepiandrosterone (DHEA) and DHEA sulfate together are abundant adrenal steroids whose physiological effects are mediated through their conversion to potent downstream androgens. 3β-Hydroxysteroid dehydrogenase isotype 1 (3βHSD1) facilitates the rate-limiting step of DHEA metabolism and gates the flux of substrate into the distal portion of the androgen synthesis pathway. Notably, a germline, missense-encoding change, HSD3B1(1245C), results in expression of 3βHSD1 protein that is resistant to degradation, yielding greater potent androgen production in the periphery. In contrast, HSD3B1(1245A) encodes 3βHSD1 protein that is easily degraded, limiting peripheral androgen synthesis. These adrenal-permissive (AP) and adrenal-restrictive (AR) alleles have recently been associated with divergent outcomes in androgen-sensitive disease states, underscoring the need to reevaluate DHEA metabolism using HSD3B1 genetics.

Cross-Sectional and Longitudinal Effects of PCB Exposure on Human Stress Hormones in the German HELPcB Surveillance Program

Multiple pathological associations are attributed to PCBs (polychlorinated biphenyls). Research shows a positive association of PCBs with dehydroepiandrosterone sulfate (DHEAS) concentration but the results on the stress hormone cortisol have been inconsistent so far. This study is the first to examine not only the cross-sectional but also the longitudinal effects of PCB exposure on the stress hormones DHEAS and cortisol. Over a period of three years, 112 former employees occupationally exposed to PCBs were tested for their body burden with different types of PCBs (lower and higher chlorinated, dioxin-like and hydroxylated) and for their stress hormone concentration. Highly exposed employees showed a significantly higher risk for higher DHEAS values. Multiple linear regression analysis revealed a positive relationship between the exposure to lower chlorinated PCBs and DHEAS. Mixed models also revealed a significantly positive correlation between lower chlorinated PCBs with DHEAS when controlled for a cross-section. However, an effect for cortisol was not found. These results suggest a causal pathophysiological relationship between PCB exposure and DHEAS concentration, but not with cortisol. The health consequences of high DHEAS concentrations are discussed.

Digital Delivery of Meditative Movement Training Improved Health of Cigarette-Smoke-Exposed Subjects

Many FA who flew prior to the ban on smoking in commercial aircraft exhibit an unusual pattern of long-term pulmonary dysfunction. This randomized controlled study tested the hypothesis that digitally delivered meditative movement (MM) training improves chronic obstructive pulmonary disease (COPD)-related symptoms in flight attendants (FA) who were exposed to second-hand cigarette smoke (SHCS) while flying. Phase I of this two-phase clinical trial was a single-arm non-randomized pilot study that developed and tested methods for MM intervention; we now report on Phase II, a randomized controlled trial comparing MM to a control group of similar FA receiving health education (HE) videos. Primary outcomes were the 6-min walk test and blood levels of high sensitivity C-reactive protein (hs-CRP). Pulmonary, cardiovascular, autonomic and affective measures were also taken. There were significant improvements in the 6-min walk test, the Multidimensional Assessment of Interoceptive Awareness (MAIA) score, and the COPD Assessment Test. Non-significant trends were observed for increased dehydroepiandrosterone sulfate (DHEAS) levels, decreased anxiety scores and reduced blood hs-CRP levels, and increased peak expiratory flow (PEF). In a Survey Monkey questionnaire, 81% of participants who completed pre and post-testing expressed mild to strong positive opinions of the study contents, delivery, or impact, while 16% expressed mild negative opinions. Over the course of the year including the study, participant adoption of the MM practices showed a significant and moderately large correlation with overall health improvement; Pearson's R = 0.62, p < 0.005. These results support the hypothesized benefits of video-based MM training for this population. No adverse effects were reported.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT02612389

Dehydroepiandrosterone and Erectile Function: A Review

To review the contemporary knowledge regarding the dehydroepiandrosterone and erectile function. Medline was reviewed for English-language journal articles spanning the time between January 1990 and December 2017, using the terms 'erectile function', 'dehydroepiandrosterone'. We used Journal Articles and review articles that found to be relevant to the purpose of this review. Criteria included all pertinent review articles, randomized controlled trials with tight methodological design, cohort studies and retrospective analyses. We also manually revised references from selected articles. Several interesting studies have addressed the age-related decline in dehydroepiandrosterone levels with many age-related phenomena or deterioration in various physiological functions. Particularly, aging; neurological functions including decreased well-being, cognition, and memory; increased depression, decreased bone mineral density, obesity, diabetes, increased cardiovascular morbidity, erectile dysfunction (ED), and decreased libido. Supporting this result, some trials of dehydroepiandrosterone supplementation in healthy, middle-aged, and elderly subjects have reported improvements in different aspects of well-being. Several studies had demonstrated that dehydroepiandrosterone level is declined as a part of aging. Large-scale well-designed prospective studies are warranted to better define indications and therapeutic implications of dehydroepiandrosterone in men with ED.

Efficient Biotransformation of Phytosterols to Dehydroepiandrosterone by Mycobacterium sp

In this study, a method for the efficient production of dehydroepiandrosterone (DHEA) from phytosterols in a vegetable oil/aqueous two-phase system by Mycobacterium sp. was developed. After the 3-hydroxyl group of phytosterols was protected, they could be converted into DHEA with high yield and productivity by Mycobacterium sp. NRRL B-3683. In a shake flask biotransformation, 15.05 g l^-1 of DHEA and a DHEA yield of 85.39% (mol mol^-1) were attained after 7 days with an initial substrate concentration of 25 g l^-1. When biotransformation was carried out in a 30-l stirred bioreactor with 25 g l^-1 substrate, the DHEA concentration and yield was 16.33 g l^-1 and 92.65% (mol mol^-1) after 7 days, respectively. The results of this study suggest that inexpensive phytosterols could be utilized for the efficient production of DHEA.

Farmers' Cohort for Agricultural Work-Related Musculoskeletal Disorders (FARM) Study: Study Design, Methods, and Baseline Characteristics of Enrolled Subjects

Background

The ongoing Farmers’ Cohort for Agricultural Work-related Musculoskeletal Disorders (FARM) study was developed to evaluate health status and related factors in farmers.

Methods

Farmers in Kangwon Province, South Korea, were recruited. Baseline characteristics were determined using questionnaires about sociodemographic and health characteristics and agricultural work-related factors. In addition, laboratory examinations (lumbar spinal radiography and serologic testing) were conducted.

Results

The FARM study covers eight rural areas and recruited 1013 subjects (534 women; mean [standard deviation {SD}] age, 57.2 [7.5] years). Musculoskeletal pain in multiple areas was reported by 925 subjects (91.3%), and low back pain (63.8%) was the most frequent site of pain. Farmer’s Stress Inventory (mean [SD], 77.7 [10.2]; range, 28–112] and subjective stress index (mean [SD], 5.3 [2.4]; range, 0–10) were above median scale values, reflecting a stressful condition, while the EuroQol-5D-3L index and the EuroQol-Visual Analog Scale scores were high (mean [SD], 0.9 [0.1]; range −0.171–1 and mean [SD], 67.7 [18.7]; range 0–100, respectively), reflecting good life quality. In total, 53% of participants had worked in farming for more than 30 years, and workers involved in dry-field farming comprised the largest subgroup (41.5%). Most participants (94.3%) had no more than a high school education, and families with annual income below 20 million won constituted the largest subgroup (36.3%).

Conclusions

The FARM study may provide data on the current health status and related sociodemographic and agricultural work-related risk factors in Korean farmers, with the goal of providing a scientific basis for developing coping interventions and preventive strategies.

Puberty and Age-related Changes in Susceptibility to Schistosome Infection

Recent data from outbreaks of schistosomiasis in immunologically naive populations have refuelled the debate concerning the nature or existence of protective, acquired immunity to schistosomiasis in humans. Data from endemic communities provide some compelling evidence for an abrupt change in reinfection rates that coincides with puberty. We suggest that the hormonal changes of adrenarche may hold the key to understanding the relative resistance to infection found in adults.

Could hormones make a difference in the treatment of juvenile rheumatoid arthritis?

Adrenal androgens dehydroepiandrosterone (DHEA; prasterone) and its sulphated form (DHEA-S) are among the most abundant hormonal steroids in men and nonpregnant women. Deficiencies of these adrenal androgens are associated with autoimmune disorders such as rheumatoid arthritis (RA). Recent studies from our laboratory have also identified low levels of adrenal androgens in the serum and synovial fluid of patients with juvenile rheumatoid arthritis (JRA). These findings support and complement those already published for RA and other autoimmune diseases. Because of the paucity of data on the hormonal status of patients with JRA, studies on the relationship between hypoandrogenicity and predisposition to develop JRA, and/or disease progression have not been conducted. In addition, despite the rapid expansion of research in the clinical use of these adrenal androgens in hyperlipidaemia, atherosclerosis, obesity, diabetes mellitus, insulin resistance and hypertension, their potential beneficial effects in JRA/RA have not been fully investigated. In fact, clinical trials of adrenal androgens in RA have only been conducted for the treatment of systemic lupus erythematosus. Further studies using prospective approaches are necessary to provide a unified consensus on the hormonal status of patients with JRA (as well as those with RA). This overview of our knowledge of the putative role(s) of hormones in arthritis will hopefully stimulate researchers in basic science and rheumatologists to synergistically collaborate in the effective translation of such knowledge to new clinical approaches.

Trypanosoma cruzi: the effects of dehydroepiandrosterone (DHEA) treatment during experimental infection

The aim of this study was to evaluate the efficacy of the immunomodulator dehydroepiandrosterone (DHEA) in the treatment of Trypanosoma cruzi infection and the possible biochemistry alterations in male and female Wistar rats. DHEA also known as the steroid of multiple actions has attracted distinct medical areas. Prior studies show that DHEA enhances immune responses against a wide range of viral, bacterial and parasitic pathogens. Furthermore, administration of DHEA seems to protect animals against obesity and diabetes. Male animals subcutaneous treated with 40 mg/kg body weight/day of DHEA displayed a significant reduction in blood parasites during parasitaemia peak, when compared to untreated animals (P<0.001). For female group parasitaemia was also reduced although values are not statistically significant (P>0.05). Sexual dimorphism was also observed, since females displayed lesser parasitaemia levels compared to males group treated (P>0.05) and untreated (P<0.001). Enhanced leucocytes number was observed in control females when compared to control males (P<0.05). DHEA treatment did not triggered any significant alterations in leucocytes levels (P>0.05). DHEA administration induced an enhanced number of macrophages in infected male (P<0.01). DHEA administration causes a decrease in glucose (P<0.001). Cholesterol and tryglicerides levels did not display results statistically significant (P>0.05) during the treatment. These results suggest that DHEA treatment enhances the immune response as evidenced here by reduced levels of parasites. Up-regulation of the immune system by exogenous DHEA may be useful in the treatment of American tripanosomiasis.

Dehydroepiandrosterone inhibits the proliferation of human umbilical vein endothelial cells by enhancing the expression of p53 and p21, restricting the phosphorylation of retinoblastoma protein, and is androgen- and estrogen-receptor independent

Dehydroepiandrosterone (DHEA), a steroid hormone, modified the proliferation of human umbilical vein endothelial cells in a dose-dependent manner. Its inactive sulfate ester (DHEA-S) and two of its metabolites -- estradiol and testosterone -- had no inhibitory effect at physiological concentrations. Antiproliferation was associated with arrest in the G1 phase of the cell cycle, but not with cell death, as evaluated by cleavage of poly(ADP-ribose) polymerase and exposure of phosphatidylserine. The effect was not blocked by inhibitors of androgen or estrogen receptors. DHEA diminished the levels of phosphorylated retinoblastoma protein and increased the expression of p53 and p21 mRNAs. These results show that DHEA inhibits endothelial cell proliferation by regulating cell cycle relevant proteins through a cytoplasmic steroid hormone-independent pathway.

Age-related decline in RACK-1 expression in human leukocytes is correlated to plasma levels of dehydroepiandrosterone

Aging is associated with remodeling of the immune system, contributing to increased incidence of infections, autoimmune diseases, and cancer among the elderly. Alterations in several signal transduction pathways have been reported to play an important role in immunosenescence. We show that peripheral blood leukocytes obtained from old donors (> or =65 years) have a significantly reduced expression of receptor for activated C kinase 1 (RACK-1), a protein required for protein kinase C (PKC)-beta signaling, as compared with young donors (< or =40 years), both in males and females. The decline in RACK-1 immunoboth in reactivity was age-related (Spearman correlation, r=-0.278, P=0.012). All leukocyte subpopulations, namely lympho-monocytes, granulocytes, and B and T cells, showed a similar defect. We also observed a direct correlation between circulating dehydroepiandrosterone (DHEA) and RACK-1 expression in leukocytes (Spearman correlation, r=0.388, P=0.001). Furthermore, in vitro treatment with DHEA resulted in increased RACK-1 expression in leukocytes and lymphocyte proliferation, confirming the role of this hormone in the modulation of its expression and immune functions. A relevant consequence of RACK-1-reduced expression was the observation that release of tumor necrosis factor alpha following lipopolysaccharide challenge and mitogen-induced lymphocye proliferation, which involves PKC-beta activation, was significantly reduced in elderly subjects. Overall, our findings contribute to the understanding of the complex process of immunosenescence and identify age-related loss in immunological responses as partially associated with decreased RACK-1 expression.

Dehydroepiandrosterone sulfate (DHEAS) and health: does the relationship differ by sex?

This study uses data from a large, nationally representative sample of older Taiwanese (aged 54 and older in 2000) to investigate sex differences in the relationship between DHEAS and various health outcomes. Data collection included an individual interview, a physical examination, and samples of blood and (12-h) urine. Regression models of health outcomes on DHEAS are estimated in two steps: first, including only controls for age and sex as well as an interaction between DHEAS and sex; and second, adding covariates likely to be related to both DHEAS and health outcomes (e.g. smoking). Results reveal that higher levels of DHEAS are associated with fewer mobility limitations (especially for women), better cognitive function (among women but not men), and better self-rated health (significant only for men but of similar magnitude for women). These findings are in contrast to previous studies conducted in the US and Europe that generally find stronger associations for men than women. Also unlike previous studies, which often demonstrate a negative relationship between DHEAS and depressive symptoms at least for women, we find little evidence of such a relationship for either sex.

Aging, Physical Activity, and Hormones in Women—A Review

Women experience significant changes in endocrine function during aging. Decreasing levels of anabolic hormones may be associated with musculoskeletal atrophy and decrease in function that is observed in older women and, as a result, there has been an increase in the use of pharmacological hormone therapies. It is difficult to distinguish, however, between physiological changes that are truly age related and those that are associated with lifestyle factors such as physical activity participation. Some research has shown that circulating levels of anabolic hormones such as DHEA(S) and IGF-I in older women are related to physical activity, muscle function, and aerobic power. Exercise-intervention studies have generally shown that increasing age blunts the acute hormonal response to exercise, although this might be explained by a lower exercise intensity in older women. There have been relatively few studies that examine hormonal adaptations to exercise training. Physical activity might have an effect on hormone action as a result of changes in protein carriers and receptors, and future research needs to clarify the effect of age and exercise on these other components of the endocrine system. The value and safety of hormone supplements must be examined, especially when used in combination with an exercise program.

The relationships between dehydroepiandrosterone sulphate (DHEAS), the intensity of Schistosoma mansoni infection and parasite-specific antibody responses. A cross-sectional study in residents of endemic communities in north-east Ethiopia

There are speculations that the puberty-related hormone dehydroepiandrosterone sulphate (DHEAS) might influence the intensity of infection and immune responses during Schistosoma infections. We studied the relationships between DHEAS, intensity of Schistosoma mansoni infection and humoral immune responses in 135 residents of Ethiopia. Serum levels of eight antibody isotypes against worm and egg antigens were determined by ELISA. DHEAS was measured with an immunoluminometric assay. There was a significant negative correlation between serum levels of DHEAS and intensity of S. mansoni infection. A significant increase in serum levels of DHEAS in the age group 15-19 years was accompanied by a progressive decline in the intensity of infection. Peak level of DHEAS coincided with the lowest intensity of infection in the age group 20-29 years. Multiple regression analysis showed that DHEAS alone had a significant (p<0.0001) negative effect when the effect of age was removed. Age also had a significant (p<0.0001) negative effect on the intensity of infection, after removing the effect of DHEAS. The two predictive variables accounted for 34.4% of the decline in the intensity of infection. Age accounted for 24.9%, whereas DHEAS accounted for 15.2% when the effect of each of the variables was removed. DHEAS had significant negative effects on AWA-specific IgG (p=0.02) and IgG1 (p=0.018) and SEA-specific IgG1 (p=0.009), after adjusting for the effect of age.

Steroid and sterol 7-hydroxylation: ancient pathways

B-ring hydroxylation is a major metabolic pathway for cholesterols and some steroids. In liver, 7 alpha-hydroxylation of cholesterols, mediated by CYP7A and CYP39A1, is the rate-limiting step of bile acid synthesis and metabolic elimination. In brain and other tissues, both sterols and some steroids including dehydroepiandrosterone (DHEA) are prominently 7 alpha-hydroxylated by CYP7B. The function of extra-hepatic steroid and sterol 7-hydroxylation is unknown. Nevertheless, 7-oxygenated cholesterols are potent regulators of cell proliferation and apoptosis; 7-oxygenated derivatives of DHEA, pregnenolone, and androstenediol can have major effects in the brain and in the immune system. The receptor targets involved remain obscure. It is argued that B-ring modification predated steroid evolution: non-enzymatic oxidation of membrane sterols primarily results in 7-oxygenation. Such molecules may have provided early growth and stress signals; a relic may be found in hydroxylation at the symmetrical 11-position of glucocorticoids. Early receptor targets probably included intracellular sterol sites, some modern steroids may continue to act at these targets. 7-Hydroxylation of DHEA may reflect conservation of an early signaling pathway.

Allostatic load as a predictor of functional decline. MacArthur studies of successful aging

Allostatic load has been proposed as a cumulative measure of dysregulation across multiple physiological systems, and has been postulated to impact health risks. In the allostatic load model, increased risk is hypothesized to result not only from large and clinically significant dysregulation in individual systems, but also from more modest dysregulation, if present in multiple systems. Our objective was to construct an allostatic load score by optimally combining several physiologic measurements, and to examine its association with future functional decline. We analyzed data from a 7-year longitudinal study of a community-based cohort, whose age at baseline was between 70 and 79 years. Canonical correlation analysis was used to study the association of 10 biological measurements representing allostatic load with declines in scores on five tests each of physical and cognitive function over two follow-up periods: 1998-1991 and 1991-1995. We used bootstrapping to evaluate the stability of the canonical correlation and canonical weights. The canonical correlation between allostatic load and the 20 decline scores was 0.43 (P =.03) and the [25th, 75th] percentile interval of its distribution over 200 bootstrapped subsamples of the cohort was [0.48, 0.53]. These findings were not substantially affected by adjusting for covariates and cardiovascular disease. We conclude that a summary measure of physiologic dysregulation, such as allostatic load, is an independent predictor of functional decline in elderly men and women.

Sex differences in androgen receptor immunoreactivity in basal forebrain nuclei of elderly and Alzheimer patients

The vertical limb of the diagonal band of Broca (VDB or Ch2) and the nucleus basalis of Meynert (NBM or Ch4) are major cholinergic nuclei of the human basal forebrain, a complex that is affected in Alzheimer's disease (AD). Sex hormones influence the function of these cholinergic neurons in animals and humans and we showed earlier that estrogen and androgen receptors (AR) are present in both the VDB and the NBM of young patients of 20-39 years of age. The aim of the present study was to investigate whether AR expression changes in relation to aging and AD. In both brain areas of male and female patients over the age of 56 nuclear staining had almost disappeared and cytoplasmic AR expression was decreased. This decrease was most pronounced in the VDB of men. In addition, the proportion of neurons showing cytoplasmic AR expression was higher in control aged women than in control aged men in both the VDB and the NBM. Surprisingly, cytoplasmic ARs were significantly decreased in the VDB and the NBM only in AD women and not in AD men. These observations suggest the possible involvement of androgens in the functional changes of the basal forebrain nuclei in aging and AD.

DHEA and sport

Dehydroepiandrosterone (DHEA), a 19-carbon steroid, is situated along the steroid metabolic pathway. It is the most abundant circulating hormone in the body and can be converted to either androgens or estrogens. It is readily conjugated to its sulphate ester DHEAS, and they are designated as DHEA(S) here when used together. Its secretion reaches a peak in early adulthood and thereafter decreases, until approximately age 70 years when it reaches a concentration of approximately 20%. Many hormonal changes may take place with aging but none is as marked as this. This "relative DHEA deficiency" resulted in DHEA being enthusiastically labelled by some as a fountain of youth or an antidote to aging that would prove to be the panacea they are seeking. Its use was also taken up enthusiastically by the athletic community and used as a prohormone in the belief or hope that it would be converted mainly to testosterone in the body.

In vivo dehydroepiandrosterone restores age-associated defects in the protein kinase C signal transduction pathway and related functional responses

Elderly subjects are at increased risk of pneumonia, influenza, and tuberculosis. Besides the known age-related decrease in mechanisms for mechanical clearance of the lungs, impaired alveolar macrophage function contributes to the increased risk of illness in the elderly. We have previously shown that age-induced macrophage immunodeficiencies are associated with a defective system for anchoring protein kinase C. Castration of young male rats produces effects on alveolar macrophages similar to those of aging, suggesting a relationship between circulating sex hormones, particularly androgens, and the decreases in the receptor for activated C kinase (RACK-1) and macrophage function observed. The aging process in humans and rats is associated with a decline in the plasma concentrations of dehydroepiandrosterone (DHEA) and its sulfate, among other steroid hormones. We report here that in vitro and in vivo administration of DHEA to rats restores the age-decreased level of RACK-1 and the LPS-stimulated production of TNF-alpha in alveolar macrophages. DHEA in vivo also restores age-decreased spleen mitogenic responses and the level of RACK-1 expression. These findings suggest that the age-related loss in immunological responses, linked to defective pathways of signal transduction, are partially under hormonal control and can be restored by appropriate replacement therapy.

Stimulation of Th2 response by high doses of dehydroepiandrosterone in KLH-primed splenocytes

Although dehydroepiandrosterone (DHEA) has long been considered as a precursor for steroid hormones, it has also been shown to have regulatory effects in immune homeostasis. We have examined the effect of high DHEA doses on T cell proliferation, differentiation, and cytokine secretion patterns following stimulation with mitogens and soluble antigens. DHEA profoundly inhibited T cell receptor-mediated T cell proliferation in the upstream of IL-2R signaling. Addition of DHEA to KLH-primed splenocytes stimulated Th2 response, indicated by an increase of IL-4 or a decrease of IFN-gamma production in the cultures. Further studies showed that DHEA enhanced IL-4, but inhibited IL-12-mediated T cell proliferation and IL-12 production in antigen-presenting cells (APCs). Our data demonstrated that supraphysiologic levels of DHEA favored Th2 immune responses in vitro by inhibition of IL-12 production from APCs and/or stimulation of Th2 proliferation during the interactions of T cells with APCs.

The study of crystallization of estrogenic 17beta-hydroxysteroid dehydrogenase with DHEA and DHT at elevated temperature

Most crystallization experiments of macromolecules are carried out at a constant temperature. Room temperature (22 degrees C) and 4 degrees C are the most widely used settings in crystallization. In practice, crystal growth at relatively high temperatures has often been avoided for macromolecular crystallization. Human estrogenic 17beta-hydroxysteroid dehydrogenase has been crystallized in complex with dehydroepiandrosterone or dihydrotestosterone. The crystallization experiments were carried out at 27 degrees C. The 17beta-HSD1 crystals were greatly improved at the elevated temperature. The effects of higher temperatures on crystal growth were studied. High temperatures stimulated the nucleation of 17beta-HSD1, increased the rate of crystal growth, and higher occupancy of substrates was obtained in the crystal structure. This method also reduced the formation of twin crystals. Since temperature is the easiest factor to control in the laboratory, crystallization at elevated temperatures provides an efficient method to improve protein crystal growth. The mechanism of the effect of temperature and relative techniques are discussed.

Influence of oral dehydroepiandrosterone (DHEA) on urinary steroid metabolites in males and females

Oral dehydroepiandrosterone (DHEA) replacement therapy may have a multitude of potential beneficial effects and exerts its action mainly via peripheral bioconversion to androgens (and estrogens). A daily dose of 50-mg DHEA has been shown by us and others to restore low endogenous serum DHEA concentrations to normal youthful levels followed by an increase in circulating androgens and estrogens. As the hepatic first-pass effect may lead to a non physiological metabolism of DHEA after oral ingestion we studied the influence of two single DHEA doses (50 and 100 mg) on the excretion of steroid metabolites in 14 elderly males [age 58.8+/-5.1 years (mean +/- SEM)] with endogenous DHEAS levels <1500 ng/ml and in 9 healthy females (age 23.3+/-4.1 years) with transient suppression of endogenous DHEA secretion induced by dexamethasone (dex) pretreatment (4x0.5 mg/day/4 days). Urinary steroid profiles in the elderly males were compared to the steroid patterns found in 15 healthy young men (age 28.9+/-5.1 years). In the females the results were compared to their individual baseline excretion without dex pretreatment. Urinary steroid determinations were carried out by semiautomatic capillary gas-liquid chromatography. In both genders DHEA administration induced significant increases in urinary DHEA (females: baseline vs. 50 mg vs. 100 mg: 361+/-131 vs. 510+/-264 vs. 1541+/-587 microg/day; males: placebo vs. 50 mg vs. 100 mg: 434+/-154 vs. 1174+/-309 vs. 4751+/-1059 microg/day) as well as in the major DHEA metabolites androsterone (A) and etiocholanolone (Et). Fifty mg DHEA led to an excretion of DHEA and its metabolites only slightly above baseline levels found in young females and in young men, respectively, whereas 100 mg induced clearly supraphysiological values. After 50 mg DHEA the ratios of urinary DHEA metabolites (A/DHEA, Et/DHEA) were not significantly different between elderly males vs. young male volunteers and young healthy females versus their individual baseline levels. In conclusion, an oral dose of 30 to 50 mg DHEA restores a physiological urinary steroid profile in subjects with DHEA deficiency without evidence for a relevant hepatic first-pass effect on urinary metabolites.

Dehydroepiandrosterone and dihydrotestosterone recognition by human estrogenic 17beta-hydroxysteroid dehydrogenase. C-18/c-19 steroid discrimination and enzyme-induced strain

Steroid hormones share a very similar structure, but they behave distinctly. We present structures of human estrogenic 17beta-hydroxysteroid dehydrogenase (17beta-HSD1) complexes with dehydroepiandrosterone (DHEA) and dihydrotestosterone (DHT), providing the first pictures to date of DHEA and DHT bound to a protein. Comparisons of these structures with that of the enzyme complexed with the most potent estrogen, estradiol, revealed the structural basis and general model for sex hormone recognition and discrimination. Although the binding cavity is almost entirely composed of hydrophobic residues that can make only nonspecific interactions, the arrangement of residues is highly complementary to that of the estrogenic substrate. Relatively small changes in the shape of the steroid hormone can significantly affect the binding affinity and specificity. The K(m) of estrone is more than 1000-fold lower than that of DHEA and the K(m) of estradiol is about 10 times lower than that of DHT. The structures suggest that Leu-149 is the primary contributor to the discrimination of C-19 steroids and estrogens by 17beta-HSD1. The critical role of Leu-149 has been well confirmed by site-directed mutagenesis experiments, as the Leu-149 --> Val variant showed a significantly decreased K(m) for C-19 steroids while losing discrimination between estrogens and C-19 steroids. The electron density of DHEA also revealed a distortion of its 17-ketone toward a beta-oriented form, which approaches the transition-state conformation for DHEA reduction.

Steroids and steroid-like compounds

Athletes have been searching for an "edge" in competition as long as there has been a reward for success. Anabolic-androgenic steroids have been the most popular of these ergogenic aids when winning is the only goal. The authors present a concise review of these substances, their prevalence, efficacy, adverse effects, and legality. This article also presents a steroid user profile and discusses physician perception and management of a patient who uses these drugs. The popular precursors of testosterone, dehydroepiandrosterone, and androstenedione are discussed with a review of the limited available data on these substances.

Short photoperiod affects reproductive function but not dehydroepiandrosterone concentrations in male deer mice (Peromyscus maniculatus)

Cessation of breeding is central among the suite of winter-coping strategies used by small rodents to survive energy-demanding winter conditions. Animals use photoperiod to predict the onset of winter and initiate, well in advance of deteriorating conditions, seasonal adaptations. Exposure to short photoperiod leads to regression of the reproductive system in long-day breeding animals. Likewise, exposure to short days leads to enhanced immune function among several rodent species studied. Because dehydroepiandrosterone (DHEA) increases immune function in virtually all studies reported to date, we sought to determine if DHEA concentrations might be influenced by photoperiod, thereby suggesting a mechanism whereby short photoperiod may enhance immune function. Male deer mice (Peromyscus maniculatus) were exposed to either short or long days for 10 weeks. Short photoperiods caused significant reduction in all reproductive organs measured relative to animals housed in long days. However, DHEA concentrations did not differ between short- and long-day mice. Taken together, these data suggest that short-day enhancement of immune function in deer mice is independent of DHEA concentrations.

The impact of a new emotional self-management program on stress, emotions, heart rate variability, DHEA and cortisol

This study examined the effects on healthy adults of a new emotional self-management program, consisting of two key techniques, "Cut-Thru" and the "Heart Lock-In." These techniques are designed to eliminate negative thought loops and promote sustained positive emotional states. The hypotheses were that training and practice in these techniques would yield lowered levels of stress and negative emotion and cortisol, while resulting in increased positive emotion and DHEA levels over a one-month period. In addition, we hypothesized that increased coherence in heart rate variability patterns would be observed during the practice of the techniques. Forty-five healthy adults participated in the study, fifteen of whom acted as a comparison group for the psychological measures. Salivary DHEA/DHEAS and cortisol levels were measured, autonomic nervous system function was assessed by heart rate variability analysis, and emotions were measured using a psychological questionnaire. Individuals in the experimental group were assessed before and four weeks after receiving training in the self-management techniques. The experimental group experienced significant increases in the positive affect scales of Caring and Vigor and significant decreases in the negative affect scales of Guilt, Hostility, Burnout, Anxiety and Stress Effects, while no significant changes were seen in the comparison group. There was a mean 23 percent reduction in cortisol and a 100 percent increase in DHEA/DHEAS in the experimental group. DHEA was significantly and positively related to the affective state Warmheartedness, whereas cortisol was significantly and positively related to Stress Effects. Increased coherence in heart rate variability patterns was measured in 80 percent of the experimental group during the use of the techniques. The results suggest that techniques designed to eliminate negative thought loops can have important positive effects on stress, emotions and key physiological systems. The implications are that relatively inexpensive interventions may dramatically and positively impact individuals' health and well-being. Thus, individuals may have greater control over their minds, bodies and health than previously suspected.

Dehydroepiandrosterone sulfate treatment of mice modulates infection with Schistosoma mansoni

Female mice treated with dehydroepiandrosterone sulfate early during infection were partially protected (P < 0.05-0.005) from Schistosoma mansoni infection. Hormone treatment did not modify parasite-specific cellular or humoral responses. Serum dehydroepiandrosterone sulfate levels and testosterone infection were negatively correlated, r = -0.621 and r = -0.653, respectively, with schistosome worm burden. The partial resistance to schistosome infection in dehydroepiandrosterone sulfate-treated female mice may be due to the known antischistosomular activity of testosterone.

Adrenal control of erectile function and nitric oxide synthase in the rat penis

Penile erection is a nitric oxide (NO)-mediated process that has been shown to be androgen dependent in rats. Castration reduces the activity of the penile enzyme involved in NO synthesis, nitric oxide synthase (NOS). To determine whether adrenal androgens and/or corticosteroids contribute to this control, the following groups of Fischer 344 adult male rats (n = 5-7) were studied: 1) intact, 2) castrated, 3) adrenalectomized alone, 4) castrated/adrenalectomized, 5) castrated/adrenalectomized with aldosterone (1.25 mg/kg, s.c.) and hydrocortisone (12 mg/kg, s.c.), 6) castrated/adrenalectomized with dihydrotestosterone (1.2-cm SILASTIC-brand tubing pellet; Dow Corning, Midland, MI), 7) castrated/adrenalectomized with dehydroepiandrosterone (2-cm tubing), 8) castrated/adrenalectomized with aldosterone (1.25 mg/kg, s.c.), and 9) castrated/adrenalectomized with hydrocortisone (12 mg/kg, s.c.). After 1 week, EFS was applied, and the maximal intracavernosal pressure (MIP) and mean arterial pressure (MAP) were recorded. The MIP/MAP ratio in the adrenalectomized group (0.37) was reduced to values found in the castrated group (0.40). The values in both groups were significantly less than those in intact controls (0.75). The most significant reduction in MIP/MAP was seen in the adrenalectomized/castrated group (0.16). Erectile response in animals submitted to adrenalectomy and castration was restored close to intact values with the administration of hydrocortisone and aldosterone (0.63). Similar results were obtained by the administration of either of the substances alone (0.56 and 0.67, respectively). Penile NOS activity assayed by the L-arginine/citrulline conversion was decreased by 55% in the castrated group compared with that in the intact group, but was not further reduced in the adrenalectomized/castrated or adrenalectomized groups. Penile neuronal NOS protein content, estimated by Western blot, was decreased only in the adrenalectomized/castrated animals (35%), and endothelial NOS content was not affected. These data suggest that the rat adrenal gland contributes to the maintenance of the erectile mechanism and may affect neuronal NOS content in the penis in the rat model. The possibility that hypotension may play a role in the erectile dysfunction observed in adrenalectomized rats cannot be discarded.

Recent update on the PPAR alpha-null mouse

Short-term treatment of rats and mice with peroxisome proliferators (PP) results in an increase in liver peroxisome number, marked hepatomegaly and induction of several genes encoding peroxisomal and other microsomal and mitochondrial enzymes involved in fatty acid metabolism. Chronic treatment of rodents with PP results in hepatocellular carcinoma. Species differences in PP responses have been found. For example, PP such as clofibrate and gemfibrozil, are highly effective lipid and cholesterol lowering drugs in humans but do not cause peroxisome proliferation and there is no evidence for increased liver cancers in patients receiving these drugs. A receptor, designated PP-activated receptor alpha (PPAR alpha) is capable of trans-activating reporter genes containing a PP response (PPRE), but requires the presence of both PP, 9-cis retinoic acid and another receptor called RXR alpha. However, PP may not directly bind to PPAR alpha but probably indirectly disturb cellular metabolism to liberate an endogenous ligand. Subsequent to the first identification of a PPAR alpha, other members of this receptor family were found and designated PPAR alpha, PPAR beta (also called NUC1 and PPAR delta) and PPAR gamma. The alpha form is most abundant in liver and kidney, sites of peroxisome proliferation while the other two receptors are not significantly expressed in these tissues. On the basis of tissue-specific localization and spectrum of target gene activation, the physiological function of PPAR alpha and PPAR gamma appear to be related to fatty acid metabolism and regulation of adipogenesis, respectively. To gain insight into the function of PPAR alpha and its role in the peroxisome proliferator response and hepatocellular carcinogenesis, gene targeting was used to develop a PPAR alpha-deficient mouse. These animals are resistant to the pleiotropic effects of PP and no induction of any known target gene has been found. Recent studies on the phenotypes of these mice have led to an understanding of the mechanism of action of PP. They have also provided a useful model to establish the physiological role of PPAR alpha in fatty acid homeostasis and inflammation.