DHEA and peripheral androgen and estrogen formation: intracinology

Androgens for postmenopausal women's health?

Obesity, metabolic syndrome, and diabetes are becoming a leading health concern in the developed Countries, due to their link to cardiovascular disease. These conditions are common in women in the post-menopausal period. Unfortunately, actual lifestyle change strategy fail to prevent cardiovascular events for several reasons, thus specific medications are needed. In addition, it was showed an increased cardiovascular diseases and breast cancer risk in postmenopausal women taking estrogens alone or with progestin, thus the optimal therapy for the prevention of chronic disease in women is still lacking. Androgens exert different actions on organs like adipose tissue, brain, bone, and on cardiovascular system. However, a debate still exists on the positive role of androgens on human health, especially in women. Furthermore, the vascular effects of androgens remain poorly understood and have been controversial for a long time. Sex hormones are important determinants of body composition. Aging is, often, accompanied by a decrease in free testosterone levels, a concomitant reduction in muscle mass and an increase in fat mass. Furthermore, numerous studies showed that total serum testosterone levels were inversely related to the atherosclerosis disease incidence in postmenopausal women. New therapeutic targets may, therefore, arise understanding how androgen could influence the fat distribution, the metabolic disease onset, the vascular reactivity and cardiovascular risk, in both sex.

Androgen action and metabolism in prostate cancer

The transcriptional programs regulated through the activity of the androgen receptor (AR) modulate normal prostate development and the maintenance of prostatic functions at maturity. AR signaling also controls key survival and growth functions operative in prostate cancer. Inhibiting the AR program remains the key target in the treatment of advanced prostate cancer, and suppressing AR also holds great potential for preventing the development or progression of early stage prostate cancer. In this review, we detail molecular mechanisms of AR activity, cellular components contributing to the maintenance of AR signaling despite AR-ligand suppression, and discuss treatment strategies designed to target components of resistance to AR-directed therapeutics.

Androgens and breast cancer in men and women

Abundant clinical evidence suggests that androgens normally inhibit mammary epithelial proliferation and breast growth. Clinical and nonhuman primate studies support the notion that androgens inhibit mammary proliferation and, thus, may protect from breast cancer. On the other hand, administration of conventional estrogen treatment suppresses endogenous androgens and may, thus, enhance estrogenic breast stimulation and possibly breast cancer risk. Addition of testosterone to the usual hormone therapy regimen may diminish the estrogen/progestin increase in breast cancer risk, but the impact of this combined use on mammary gland homeostasis still needs evaluation.

Sex hormone and neuroendocrine aspects of the metabolic syndrome

We discuss the recent advances in the knowledge that the sex steroids testosterone (T), estradiol and dehydroepiandrosterone sulphate (DHEA-S) are involved in the development of visceral obesity and of the metabolic syndrome. Cross talk between leptin and the androgen receptor (AR) in the hypothalamus as well as the peripheral conversion of DHEA and T to estrone, estradiol and dihydrotestosterone (DHT) in adipocytes and hepatocytes play important roles in the metabolic syndrome in men. Finally, we discuss the development of new drugs, selective AR modulators, for treating the metabolic syndrome in men.

DHEA improves impaired activation of Akt and PKC zeta/lambda-GLUT4 pathway in skeletal muscle and improves hyperglycaemia in streptozotocin-induced diabetes rats

AIM

Addition of dehydroepiandrosterone (DHEA) to a cultured skeletal muscle locally synthesizes 5alpha-dihydrotestosterone (DHT). It induced activation of glucose metabolism-related signalling pathway via protein kinase B (Akt) and protein kinase C zeta/lambda (PKC zeta/lambda)-glucose transporter-4 (GLUT4) proteins. However, such an effect of DHEA in vivo remains unclear.

METHODS

Using streptozotocin (STZ)-induced rats with type 1 diabetes mellitus, we tested the hypothesis that a single bout of DHEA injection in the rats improves hyperglycaemia and muscle GLUT4-regulated signalling pathway. After 1 week of STZ injection (55 mg kg(-1)) with male Wistar rats, fasting glucose concentrations were determined in a blood sample taken from the tail vein. Blood glucose levels were then monitored for 180 min after DHEA or sesame oil (control) was injected (n = 10 for each group).

RESULTS

Blood glucose levels decreased significantly for 30-150 min after 2 mg DHEA injection in the STZ rats. In the skeletal muscle, expression and translocation of GLUT4 protein, phosphorylation of Akt and PKC zeta/lambda, and phosphofructokinase and hexokinase enzyme activities increased significantly by DHEA injection. However, DHEA-induced improvements in Akt and PKC zeta/lambda-GLUT4 pathways were blocked by a DHT inhibitor.

CONCLUSION

These results suggest that a single bout of DHEA injection can improve hyperglycaemia and activate the glucose metabolism-related signalling pathway via Akt and PKC zeta/lambda-GLUT4 proteins of skeletal muscles in rats. Moreover, these results show that a DHEA-induced increase in muscle glucose uptake and utilization might contribute to improvement in hyperglycaemia in type 1 diabetes mellitus.

Trajectories of dehydroepiandrosterone sulfate predict mortality in older adults: the cardiovascular health study

BACKGROUND

Dehydroepiandrosterone sulfate (DHEAS) has been proposed as an antiaging hormone, but its importance is unclear. Assessment of an individual's ability to maintain a DHEAS set point, through examination of multiple DHEAS levels over time, may provide insight into biologic aging.

METHODS

Using Cox proportional hazard models, we examined the relationship between DHEAS trajectory patterns and all-cause death in 950 individuals aged >or=65 years who were enrolled in the Cardiovascular Health Study and had DHEAS levels measured at three to six time points.

RESULTS

Overall, there was a slight decline in DHEAS levels over time (-0.013 microg/mL/y). Three trajectory components were examined: slope, variability, and baseline DHEAS. When examined individually, a steep decline or extreme variability in DHEAS levels was associated with higher mortality (p < .001 for each), whereas baseline DHEAS level was not. In adjusted models including all three components, steep decline (hazard ratio [HR] 1.75, confidence interval [CI] 1.32-2.33) and extreme variability (HR 1.89, CI 1.47-2.43) remained significant predictors of mortality, whereas baseline DHEAS level remained unpredictive of mortality (HR 0.97 per standard deviation, CI 0.88-1.07). The effect of trajectory pattern was more pronounced in men than in women. Individuals with both a steep decline and extreme variability in DHEAS levels had a significantly higher death rate than those with neither pattern (141 vs 48 deaths per 1,000 person-years, p < .001).

CONCLUSIONS

Our data show significant heterogeneity in the individual trajectories of DHEAS levels and suggest that these trajectories provide important biologic information about the rate of aging, whereas the DHEAS level itself does not.

Effect of the Pro12Ala polymorphism of the PPAR gamma 2 gene on response to pioglitazone treatment in menopausal women

OBJECTIVE

To investigate the influence of the Pro12Ala polymorphism of the PPAR gamma 2 gene on metabolic and hormonal response to pioglitazone treatment in obese postmenopausal women.

DESIGN

We included 102 obese (body mass index [BMI] >or=30 kg/m2) and 97 nonobese (BMI <or=27 kg/m2) postmenopausal women. Anthropometric data were collected, and fasting glucose, insulin, leptin, follicle-stimulating hormone, luteinizing hormone, dehydroepiandrosterone, dehydroepiandrosterone sulfate, testosterone, estrone, estradiol, and adiponectin were measured and the PPAR gamma 2 Pro12Ala genotypes were determined. Eighty-three obese postmenopausal women were treated with pioglitazone 15 mg/day for 15 days, and hormone levels and insulin resistance (homeostasis model assessment of insulin resistance) were assessed before and after treatment.

RESULTS

Obese women had a higher BMI, waist-to-hip ratio, fasting glucose, insulin, homeostasis model assessment of insulin resistance, leptin, dehydroepiandrosterone, estradiol, testosterone, and adiponectin levels, whereas the follicle-stimulating hormone level was lower. Genotype frequencies were similar in obese and nonobese women. Analysis of the whole group showed that women with the Pro/Ala genotype had a higher BMI, waist-to-hip ratio, and fasting glucose (P < 0.04, P < 0.02, and P < 0.004, respectively) than the group with the Pro/Pro genotype. After pioglitazone treatment, glucose levels decreased in both genotypes, but at a greater amount in carriers of the Pro/Ala genotype (-15 mg/dL vs -7 mg/dL, P < 0.003). However, insulin and homeostasis model assessment of insulin resistance levels were lower in carriers of the Pro/Pro genotype (-4.0 vs 0.7 IU/L, P=0.009 and -1.0 vs -0.08, P = 0.03, respectively).

CONCLUSIONS

The Pro/Ala genotype of PPAR gamma 2 was associated with obesity and higher fasting glucose. Pioglitazone treatment in obese women with the Pro/Ala genotype induced a greater glucose decrease, and obese women may derive more benefit from this drug.

Steroid-converting enzymes in human ovarian carcinomas

Anti-estrogen therapies for treating ovarian carcinoma have had mixed outcomes suggesting some tumors may be estrogen-dependent. We assayed the activity levels of 17beta-hydroxysteroid dehydrogenase (17beta-HSD), 3beta-hydroxysteroid dehydrogenase (3beta-HSD), 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD/3-KSR) and estrone sulfatase in a series of ovarian epithelial carcinomas. 17beta-HSD activity ratios with estradiol (E(2)) and testosterone (T), and inhibition by isoform-specific inhibitors were used to estimate the contributions of 17beta-HSD isoforms. Activity levels were highest for estrone sulfatase, followed, respectively by 17beta-HSD, 3alpha-HSD/3-KSR, and 3beta-HSD. E(2)/T activity ratios varied widely between samples. A 17beta-HSD type 1 inhibition pattern was observed in 23% of the samples and a type 2 pattern in 25%. E(2) formation from estrone sulfate (E(1)S) was detected in 98% (47/48) of the samples. 17beta-HSD type 1, type 2 and type 5 mRNA was detected in matched primary tumor and metastases. Evaluation of 17beta-HSD and sulfatase activity levels, activity ratios and inhibition patterns may help predict tumor response to endocrine therapy.

17Beta-hydroxysteroid dehydrogenase enzymes and breast cancer

Sex steroids play an important role in the development and differentiation in several tissues. Biologically active hormones that are locally converted in endocrine organs in the tissue where they exert their effects without release into extracellular space is a field of endocrinology that has been called intracrinology. In pre-menopausal women the ovary is the main source of estrogens, but in post-menopausal women the estrogen production as main site of synthesis moves to peripheral tissues and almost all of the sex steroids are synthesised from precursors of adrenal origin. In breast cancer 60-80% of the tumors express high levels of oestrogen receptor (ER) alpha which gives estrogen a proliferative effect. Breast tumors tend to have a higher intratumoral estrogen concentration than normal breast tissue and plasma, and in situ synthesis and the metabolism of estrogens is believed to be of great importance for the development and progression of the disease. The activity of estrogen metabolizing enzymes in breast are mainly aromatase, estrone sulfatases and 17HSD enzymes. 17HSD1 and 17HSD2 are the family members known to be of main importance in breast cancer. High expression of 17HSD1 has been associated to poor prognosis in breast cancer and late relapse among patients with ER-positive tumors. One of the mechanisms behind high 17HSD1 expression is gene amplification. Low or absent expression of 17HSD2 is associated to decreased survival in ER-positive breast cancer. 17HSD14 is one of the latest discovered 17HSD enzymes, transfection of 17HSD14 in human breast cancer cells significantly decreased the levels of estradiol in the culture medium. Low expression of 17HSD14 mRNA expression in breast cancer was correlated to decreased survival. The understanding of intratumoral synthesis of sex steroids in breast cancer is crucial to understand the disease both in pre- and post-menopausal women. Further studies are desirable to state the direct role of these enzymes in breast cancer and which patients that may benefit from new therapeutic strategies targeting 17HSD enzymes. The new inhibitors targeting 17HSD1 have shown promising results in pre-clinical studies to have clinical potential in the future.

Effect of resistance exercise on muscle steroidogenesis

Circulating testosterone is elevated acutely following resistance exercise (RE) and is an important anabolic hormone for muscle adaptations to resistance training. The purpose of this study was to examine the acute effect of heavy RE on intracrine muscle testosterone production in young resistance-trained men and women. Fifteen young, highly resistance-trained men ( n = 8; 21 ± 1 yr, 175.3 ± 6.7 cm, 90.8 ± 11.6 kg) and women ( n = 7; 24 ± 5 yr, 164.6 ± 6.7 cm, 76.4 ± 15.6 kg) completed 6 sets of 10 repetitions of Smith machine squats with 80% of their 1-repetition maximum. Before RE and 10 and 70 min after RE, muscle biopsies were obtained from the vastus lateralis. Before RE, after 3 and 6 sets of squats, and 5, 15, 30, and 70 min into recovery from RE, blood samples were obtained using venipuncture from an antecubital vein. Muscle samples were analyzed for testosterone, 17β-hydroxysteroid dehydrogenase (HSD) type 3, and 3β-HSD type 1 and 2 content. Blood samples were analyzed for glucose and lactate concentrations. No changes were found for muscle testosterone, 3β-HSD type 1 and 2, and 17β-HSD type 3 concentrations. However, a change in protein migration in the Bis-Tris gel was observed for 17β-HSD type 3 postexercise; this change in migration indicated an ∼2.8 kDa increase in molecular mass. These findings indicate that species differences in muscle testosterone production may exist between rats and humans. In humans, muscle testosterone concentrations do not appear to be affected by RE. This study expands on the current knowledge obtained from animal studies by examining resting and postexercise concentrations of muscle testosterone and steroidogenic enzymes in humans.

Mesenchymal stem cells and cardiac repair

Accumulating clinical and experimental evidence indicates that mesenchymal stem cells (MSCs) are promising cell types in the treatment of cardiac dysfunction. They may trigger production of reparative growth factors, replace damaged cells and create an environment that favours endogenous cardiac repair. However, identifying mechanisms which regulate the role of MSCs in cardiac repair is still at work. To achieve the maximal clinical benefits, ex vivo manipulation can further enhance MSC therapeutic potential. This review focuses on the mechanism of MSCs in cardiac repair, with emphasis on ex vivo manipulation.

Aromatase inhibitors in ovarian cancer: is there a role?

Estrogen plays a role in ovarian tumorigenesis. Aromatase is the enzyme required for the synthesis of estrogen via conversion of androgen to estrogen, which is the major source of estrogen in postmenopausal women. Aromatase is present in normal ovaries and other tissues (e.g., fat and muscle) as well as in 33-81% tumor tissues of ovarian cancer. Aromatase inhibitors (AIs) block estrogen synthesis by inhibiting aromatase activity. In patients with recurrent ovarian cancer, single-agent AI therapy has been shown to elicit clinical response rates of up to 35.7% and stable disease rates of 20-42%. Given the limited treatment options for recurrent ovarian cancer and the favorable safety profile and convenient use, AI is a rational option for prolonging platinum-free interval in recurrent ovarian cancer. Further studies are required to determine the efficacy of combination treatment with AIs and biological agents, determine the benefit of AIs for treating special types of ovarian cancer (e.g., endometrioid type), and identify biomarkers for targeted patient selection. This review summarizes the current epidemiologic, preclinical, and clinical data regarding estrogen's role in ovarian cancer, the expression and regulation of aromatase in this disease, the development and characteristics of the three generations of AIs, and the preclinical and clinical studies of AIs in the treatment of ovarian cancer.

Testosterone and DHEA activate the glucose metabolism-related signaling pathway in skeletal muscle

Circulating dehydroepiandrosterone (DHEA) is converted to testosterone or estrogen in the target tissues. Recently, we demonstrated that skeletal muscles are capable of locally synthesizing circulating DHEA to testosterone and estrogen. Furthermore, testosterone is converted to 5alpha-dihydrotestosterone (DHT) by 5alpha-reductase and exerts biophysiological actions through binding to androgen receptors. However, it remains unclear whether skeletal muscle can synthesize DHT from testosterone and/or DHEA and whether these hormones affect glucose metabolism-related signaling pathway in skeletal muscles. We hypothesized that locally synthesized DHT from testosterone and/or DHEA activates glucose transporter-4 (GLUT-4)-regulating pathway in skeletal muscles. The aim of the present study was to clarify whether DHT is synthesized from testosterone and/or DHEA in cultured skeletal muscle cells and whether these hormones affect the GLUT-4-related signaling pathway in skeletal muscles. In the present study, the expression of 5alpha-reductase mRNA was detected in rat cultured skeletal muscle cells, and the addition of testosterone or DHEA increased intramuscular DHT concentrations. Addition of testosterone or DHEA increased GLUT-4 protein expression and its translocation. Furthermore, Akt and protein kinase C-zeta/lambda (PKC-zeta/lambda) phosphorylations, which are critical in GLUT-4-regulated signaling pathways, were enhanced by testosterone or DHEA addition. Testosterone- and DHEA-induced increases in both GLUT-4 expression and Akt and PKC-zeta/lambda phosphorylations were blocked by a DHT inhibitor. Finally, the activities of phosphofructokinase and hexokinase, main glycolytic enzymes, were enhanced by testosterone or DHEA addition. These findings suggest that skeletal muscle is capable of synthesizing DHT from testosterone, and that DHT activates the glucose metabolism-related signaling pathway in skeletal muscle cells.

Potential biomarkers of ageing

Life span in individual humans is very heterogeneous.Thus, the ageing rate, measured as the decline of functional capacity and stress resistance, is different in every individual. There have been attempts made to analyse this individual age, the so-called biological age, in comparison to chronological age. Biomarkers of ageing should help to characterise this biological age and, as age is a major risk factor in many degenerative diseases,could be subsequently used to identify individuals at high risk of developing age-associated diseases or disabilities. Markers based on oxidative stress, protein glycation,inflammation, cellular senescence and hormonal deregulation are discussed.

Steroidal lactones as inhibitors of 17beta-hydroxysteroid dehydrogenase type 5: chemical synthesis, enzyme inhibitory activity, and assessment of estrogenic and androgenic activities

Androgens are well known to play a predominant role in prostate cancer and other androgen-dependent diseases. To decrease the level of androgen testosterone in the prostate, we are interested in developing inhibitors of 17beta-hydroxysteroid dehydrogenase type 5 (17beta-HSD5). This enzyme expressed in the prostate is one of the two enzymes able to convert 4-androstene-3,17-dione into testosterone. From a screening study, it was found that a series of steroid derivatives bearing a lactone on D-ring demonstrated potent inhibition of 17beta-HSD5 over-expressed in HEK-293 cells. The results of enzymatic assays using intact cells indicated that a C18-steroid (estradiol or 3-deoxyestradiol) backbone and a spiro-delta-lactone (six-member ring) are important for a strong inhibitory activity. Moreover, the presence of a dimethyl group at the alpha-position of the lactone carbonyl increases the selectivity of the inhibitor toward 17beta-HSD5. Compound 26, a 3-deoxyestradiol derivative with a dimethylated spiro-delta-lactone at position 17, possesses the most potent inhibitory activity for 17beta-HSD5 (IC(50)=2.9 nM). It showed no binding affinity for estrogen, androgen, progestin and glucocorticoid receptors (ER, AR, PR and GR). A weak proliferative effect was, however, observed on ZR-75-1 (ER+) cells in culture at high concentration (1 microM), but not at 0.03 microM. Interestingly, no significant proliferative effect was detected on Shionogi (AR+) cells in culture in the presence of 0.1 and 1 microM of lactone 26.

Effects of intravaginal dehydroepiandrosterone on vaginal histomorphology, sex steroid receptor expression and cell proliferation in the rat

OBJECTIVE

Recent clinical studies have shown that postmenopausal hormone therapy with estrogen plus progestogen increases breast cancer risk. Moreover, intravaginal estrogen-containing pills, creams and rings lead to significant systemic exposure to estrogen, thus indicating the need for a completely novel approach to alleviate vaginal atrophy in postmenopausal women.

DESIGN

We have studied the effect of intravaginal application of dehydroepiandrosterone at daily doses of 0.33 mg, 0.66 mg or 1mg in ovariectomized animals for 2 weeks, with the objective of inducing local beneficial effects in the vagina without significant systemic action.

RESULTS

After 2 weeks, serum dehydroepiandrosterone, androst-5-ene-3beta,17beta-diol and dehydroepiandrosterone-sulfate were increased over a 4h time period, but serum testosterone, estradiol, estrone and dihydrotestosterone remained below detectable levels. The suppository vehicle alone produced minimal epithelial thickening limited to the vaginal distal half. The morphological effects of dehydroepiandrosterone on vaginal mucosa were observed at the lowest dose and consisted mainly of a typical androgenic effect of epithelial mucification. No change in morphological features related to cell proliferation was observed at any dehydroepiandrosterone dose on uterus, mammary gland and skin. At the highest dose, body weight showed a significant decrease, thus indicating a systemic effect on lipid accumulation. Immunohistochemistry for androgen, estrogen alpha and progesterone receptors did not reveal any significant systemic effects in the uterus, mammary gland and skin except some suggestion of increased androgen receptor labeling in mammary gland and skin at the highest dehydroepiandrosterone dose.

CONCLUSION

The present data show that intravaginal dehydroepiandrosterone can exert beneficial effects limited to the vagina.

Photoperiodic mechanisms controlling scent marking: interactions of vasopressin and gonadal steroids

Microinjection of arginine vasopressin (Avp) into the rostral hypothalamus of Syrian hamsters induces a form of scent marking known as flank marking. The ability of Avp to stimulate flank marking is mediated by the vasopressin 1a receptor (Avpr1a). In hamsters housed in long 'summer-like' photoperiods, the amount of flank marking and the number of Avpr1a receptors in the rostral hypothalamus are regulated by testosterone. However, hamsters housed in short 'winter-like' photoperiods for 6-8 weeks continue to flank mark at high levels despite significant reductions in the circulating levels of testosterone. In the present study, we compared the effects of gonadal steroids on Avp-induced flank marking and Avpr1a binding and affinity in hamsters housed in short photoperiods and those housed in long photoperiods. In long-photoperiod-housed hamsters, castration significantly reduced the amount of Avp-induced flank marking; however, in short-photoperiod-housed hamsters there were no significant differences between gonadally regressed and castrated hamsters. Surprisingly, Avpr1a receptor binding, but not affinity, in the medial preoptic area and the medial preoptic nucleus was significantly reduced in long-photoperiod-housed castrates as well as short-photoperiod-housed gonadally regressed and castrated hamsters, compared with long-photoperiod-housed gonadally intact hamsters. These data demonstrate that in short photoperiods Avp-induced flank marking is independent of gonadal hormones, despite gonadal steroid-dependent reductions in Avpr1a binding.

Intracrinology of estrogens and androgens in breast carcinoma

Intratumoral metabolism and synthesis of biologically active steroids such as estradiol and 5alpha-dihydrotestosterone as a result of interactions of various enzymes are considered to play very important roles in the pathogenesis and development of hormone-dependent breast carcinoma. Among these enzymes involved in estrogen metabolism, intratumoral aromatase play an important role in converting androgens to estrogens in situ from serum and serving as the source of estrogens, especially in postmenopausal patients with breast carcinoma. However, other enzymes such as 17beta-hydroxysteroid dehydrogenase (17beta-HSD) isozymes, estrogen sulfatase (STS), and estrogen sulfotransferase, which contribute to in situ availability of biologically active estrogens, also play pivotal roles in this intratumoral estrogen production above. Androgen action on human breast carcinoma has not been well-studied but are considered important not only in hormonal regulation but also other biological features of carcinoma cells. Intracrine mechanisms also play important roles in androgen actions on human breast carcinoma cells. Among the enzymes involved in biologically active androgen metabolism and/or synthesis, both 17beta-hydroxysteroid dehydrogenase type 5 (17betaHSD5; conversion from circulating androstenedione to testosterone) and 5alpha-reductase (5alphaRed; reduction of testosterone to DHT (5alpha-dihydrotestosterone) were expressed in breast carcinoma tissues, and in situ production of DHT has been proposed in human breast cancer tissues. However, intracrine mechanisms of androgens as well as their biological or clinical significance in the patients with breast cancer have not been fully elucidated in contrast to those in estrogens.

Low circulating levels of dehydroepiandrosterone in histologically advanced nonalcoholic fatty liver disease

The biological basis of variability in histological progression of nonalcoholic fatty liver disease (NAFLD) is unknown. Dehydroepiandrosterone (DHEA) is the most abundant steroid hormone and has been shown to influence sensitivity to oxidative stress, insulin sensitivity, and expression of peroxisome proliferator-activated receptor alpha and procollagen messenger RNA. Our aim was to determine whether more histologically advanced NAFLD is associated with low circulating levels of DHEA. Serum samples were obtained prospectively at the time of liver biopsy in 439 patients with NAFLD (78 in an initial and 361 in validation cohorts) and in controls with cholestatic liver disease (n = 44). NAFLD was characterized as mild [simple steatosis or nonalcoholic steatohepatitis (NASH) with fibrosis stage 0-2] or advanced (NASH with fibrosis stage 3-4). Serum levels of sulfated DHEA (DHEA-S) were measured by enzyme-linked immunosorbent assay. Patients with advanced NAFLD had lower plasma levels of DHEA-S than patients with mild NAFLD in both the initial (0.25 +/- 0.07 versus 1.1 +/- 0.09 microg/mL, P < 0.001) and validation cohorts (0.47 +/- 0.06 versus 0.99 +/- 0.04 microg/mL, P < 0.001). A "dose effect" of decreasing DHEA-S and incremental fibrosis stage was observed with a mean DHEA-S of 1.03 +/- 0.05, 0.96 +/- 0.07, 0.83 +/- 0.11, 0.66 +/- 0.11, and 0.35 +/- 0.06 microg/mL for fibrosis stages 0, 1, 2, 3, and 4, respectively. All patients in both cohorts in the advanced NAFLD group had low DHEA-S levels, with the majority in the hypoadrenal range. The association between DHEA-S and severity of NAFLD persisted after adjusting for age. A relationship between disease/fibrosis severity and DHEA-S levels was not seen in patients with cholestatic liver diseases.

CONCLUSION

More advanced NAFLD, as indicated by the presence of NASH with advanced fibrosis stage, is strongly associated with low circulating DHEA-S. These data provide novel evidence for relative DHEA-S deficiency in patients with histologically advanced NASH.

Sex differences in steroidogenesis in skeletal muscle following a single bout of exercise in rats

Sex steroid hormones, such as testosterone and estradiol, play important roles in developing both strength and mass of skeletal muscle. Recently, we demonstrated that skeletal muscle can synthesize sex steroid hormones. Whether there are sex differences in basal steroidogenesis or acute exercise-induced alterations of steroidogenesis in the skeletal muscle is unknown. We examined sex differences in the levels of testosterone, estradiol, and steroidogenesis-related enzymes, such as 17β-hydroxysteroid dehydrogenase (HSD), 3β-HSD, and aromatase cytochrome P-450 (P450arom), in the skeletal muscle at rest and after exercise. We studied the gastrocnemius muscles of resting rats (10 wk old) and exercised rats (10 wk old, treadmill running, 30 m/min, 30 min). Basal muscular testosterone levels were higher in males than females, whereas estradiol did not differ between sexes. Additionally, 17β-HSD, 3β-HSD, and P450arom transcript and protein expression were greater in females. After acute exercise, testosterone levels and 17β-HSD expression increased in muscle in both sexes. By comparison, muscular estradiol levels increased in males following exercise but were unchanged in females. Expression of P450arom, which regulates estrogen synthesis, increased after acute exercise in males but decreased after exercise in females. Thus a single bout of exercise can influence the steroidogenic system in skeletal muscle, and these alterations differ between sexes. The acute exercise-induced alteration of steroidogenic enzymes may enhance the local steroidogenesis in the skeletal muscle in both sexes.

Chronic administration of dehydroepiandrosterone (DHEA) to female monkey and rat has no effect on mammary gland histology

Dehydroepiandrosterone (DHEA), the major steroid precursor of androgens and estrogens produced in peripheral tissues in primates, has been shown to exert chemopreventive effect on the development of carcinogen-induced rat mammary tumors. Since little is known on the effect of DHEA administration on mammary gland physiology and histology, we have studied the effect of long-term administration of DHEA to normal female monkey and rat on mammary gland histology as well as on serum DHEA, DHEA sulphate (DHEA-S), testosterone and estradiol levels. In monkeys, DHEA treatment (2 or 10 mg/(kg b.w.day)) induced a dose-related increase in serum DHEA and DHEA-S (above 20-fold) levels. At the highest dose of DHEA, serum testosterone levels were significantly increased (three- to fourfold), while serum estradiol concentration was not modified. DHEA treatment did not modify the histological characteristics of monkey mammary glands. In the rat, following DHEA administration (10 or 100 mg/(kg b.w.day)), a dose-related marked increase in serum DHEA and DHEA-S was observed. Serum testosterone was also increased in DHEA-treated animals, while no significant changes in serum estradiol levels were detected. As in the monkey, the histology of the female rat mammary gland remained unchanged following long-term treatment with any of the two doses of DHEA.

Bioavailability and metabolism of oral and percutaneous dehydroepiandrosterone in postmenopausal women

To study the bioavailability of dehydroepiandrosterone (DHEA) administered by the oral and percutaneous routes, three groups of 12 postmenopausal women aged 60-70 years received two capsules of 50mg of DHEA orally before breakfast daily for 14 days or applied 4 g of a 10% DHEA cream or gel at the same time of the day on a 30 cm x 30 cm surface area on the thighs. Detailed serial blood sampling over 24h was performed following 1st and 14th DHEA administration for measurement of DHEA and nine of its metabolites by liquid chromatography tandem mass spectrometry (LC-MS/MS) or gas chromatography mass spectrometry (GC-MS). Serum levels of estrone (E1) and estradiol (E2) did not change following DHEA administration by any of the three formulations, while serum androstenedione (4-dione), testosterone, DHEA sulfate (DHEA-S), E(1)-S, androsterone glucuronide (ADT-G) and 3alpha-androstanediol-G (3alpha-diol-G), increased in all cases, the effect on these parameters being more important after oral than percutaneous administration due to the metabolism of DHEA into these metabolites in the gastrointestinal tract and liver. No qualitative differences in DHEA metabolism are observed between the oral and percutaneous routes of DHEA administration while the levels of all steroids remain on a plateau during the 24h period during chronic percutaneous DHEA administration. The present data show that DHEA is transformed into active androgens and estrogens in peripheral intracrine tissues with no or minimal release of the active steroids E(1), E(2) or testosterone in the circulation. Moreover, DHEA is preferentially transformed into androgens rather than into estrogens. Most importantly, the present data show that changes in serum DHEA following oral or percutaneous DHEA administration are not a valid parameter of DHEA action since the increase in serum DHEA is at least 100% greater than the increase in the formation of active androgens and estrogens and thus much higher than the potential physiological effects.

Low salivary dehydroepiandrosterone and androgen-regulated cysteine-rich secretory protein 3 levels in Sjögren's syndrome

OBJECTIVE

Sjögren's syndrome (SS), an autoimmune disease of exocrine glands, typically starts at the time of adrenopause. We undertook this study to test the hypothesis that SS is characterized by an insufficient androgen effect at the target tissue level.

METHODS

We searched for androgen response elements (AREs) in the cysteine-rich secretory protein 3 (crisp-3) gene. Dehydroepiandrosterone (DHEA) responsiveness was experimentally studied using quantitative reverse transcriptase-polymerase chain reaction and immunofluorescence staining of human submandibular gland-derived acinar cells and labial salivary gland explants with or without DHEA. Finally, glandular and salivary CRISP-3 in healthy controls and SS patients was analyzed using immunohistochemistry, in situ hybridization, and enzyme-linked immunosorbent assay. Serum DHEA sulfate (DHEAS) and salivary DHEA levels were measured using a radioimmunometric method.

RESULTS

Literature analysis and a search for AREs in gene banks suggested androgen dependency of human CRISP-3, and this was verified by studies of human submandibular gland acinar cells cultured with or without DHEA, in which DHEA increased CRISP-3 messenger RNA (mRNA) levels (P = 0.018). This finding was confirmed by the results of DHEA stimulation of labial salivary gland explants. Glandular CRISP-3 mRNA and protein labeling was weak and diffuse, coupled with low secretion in saliva (mean +/- SEM 21.1 +/- 2.7 mug CRISP-3/15 minutes in SS patients versus 97.6 +/- 12.0 mug CRISP-3/15 minutes in healthy controls; P < 0.0001). Compared with healthy controls, SS patients had low serum levels of DHEAS (P = 0.008) and also low salivary levels of DHEA (mean +/- SEM 224 +/- 33 pmoles versus 419 +/- 98 pmoles; P = 0.005).

CONCLUSION

CRISP-3 pathology was seen in acini remote from lymphocyte foci and is apparently not secondary to local inflammation, but may represent some systemic effect in SS. Indeed, androgen deprivation in the salivary glands of SS patients is evidenced both by low salivary levels of DHEA and by low levels of DHEA-regulated CRISP-3. This may explain some of the characteristic features of SS.

Tearful relationships? Sex, hormones, the lacrimal gland, and aqueous-deficient dry eye

Sex and the endocrine system exert a significant influence on the physiology and pathophysiology of the lacrimal gland. The purpose of this article is to briefly review the nature and magnitude of these interactions between sex, hormones and lacrimal tissue, and to address how they may relate to the pathogenesis of aqueous-deficient dry eye. Towards this end, this article has a 3-fold approach: first, to summarize the influence of androgens, estrogens, glucocorticoids, mineralocorticoids, retinoic acid, prolactin, alpha-melanocyte stimulating hormone, adrenocorticotropic hormone, luteinizing hormone, follicle-stimulating hormone, growth hormone, thyroid-stimulating hormone, arginine vasopressin, oxytocin, thyroxine, parathyroid hormone, insulin, glucagon, melatonin, human chorionic gonadotropin and cholecystokinin on the structure and function of the lacrimal gland; second, to discuss the mechanism of action of each hormone on lacrimal tissue; and third, to discuss the clinical relevance of the endocrine-lacrimal gland interrelationship, with a particular focus on each hormone's role (i.e. if relevant) in the development of aqueous-tear deficiency.

Corticosterone inhibits the lipid-mobilizing effects of oleoyl-estrone in adrenalectomized rats

Oleoyl-estrone (OE) is an adipose-derived signal that decreases energy intake and body lipid, maintaining energy expenditure and glycemic homeostasis. Glucocorticoids protect body lipid and the metabolic status quo. We studied the combined effects of OE and corticosterone in adrenalectomized female rats: daily OE gavages (0 or 10 nmol/g) and slow-release corticosterone pellets at four doses (0, 0.5, 1.7, and 4.8 mg/d). Intact and sham-operated controls were also included. After 8 d, body composition and plasma metabolites and hormones were measured. OE induced a massive lipid mobilization (in parallel with decreased food intake and maintained energy expenditure). Corticosterone increased fat deposition and inhibited the OE-elicited mobilization of body energy, even at the lowest dose. OE enhanced the corticosterone-induced rise in plasma triacylglycerols, and corticosterone blocked the OE-induced decrease in leptin. High corticosterone and OE increased insulin resistance beyond the effects of corticosterone alone. The presence of corticosterone dramatically affected OE effects, reversing its decrease of body energy (lipid) content, with little or no change on food intake or energy expenditure. The maintenance of glycemia and increasing insulin in parallel to the dose of corticosterone indicate a decrease in insulin sensitivity, which is enhanced by OE. The reversal of OE effects on lipid handling, insulin resistance, can be the consequence of a corticosterone-induced OE resistance. Nevertheless, OE effects on cholesterol were largely unaffected. In conclusion, corticosterone administration effectively blocked OE effects on body lipid and energy balance as well as insulin sensitivity and glycemia.

Adding to the controversy: pitfalls in the diagnosis of testosterone deficiency syndromes with questionnaires and biochemistry

PURPOSE

To determine the value of available questionnaires used for the diagnosis of testosterone deficiency syndromes (TDS) by correlating their ratings with a panel of hormonal determinations in a male population.

MATERIALS AND METHODS

Participants completed the ADAM questionnaire and underwent biochemical evaluation at the local site. Assessments determined entry into Group A (symptomatic) or Group B (non-symptomatic). After stratification, subjects provided a morning sample of blood, completed the Aging Male Survey (AMS) and the newly developed Canadian Society for the Study of the Aging Male (CSAM-Q) questionnaires. Serum aliquots were analysed at a central lab for 8 putative markers commonly associated with symptomatic testosterone deficiency associated with aging: total testosterone (T); bioavailable T (BT); dehydroepiandrosterone sulphate (DHEA-S); sex-hormone binding globulin (SHBG); luteinizing hormone (LH), prolactin (PRL); thyroid-stimulating hormone (TSH) and insulin-like growth factor-1 (IGF-1).

RESULTS

92 men were screened; of these 59 (mean age of 58+/-11 years) completed the study, 30 (51%) scored positively (mean 61.5 years) to the ADAM while 29 (49%) did not (mean 54.1 years). For the AMS the weight of the three domains (psychological, somato-vegetative and sexual) was significantly greater in Group A (p<0.001) than in Group B. Equally, for the CAS questionnaire, the scores for the variables energy, global performance, frequency of intercourse, mood and quality of sleep were lower in Group A than in their asymptomatic counterparts (p<0.001). The domain of memory assessment within the CSSAM-Q was not discriminatory. ADAM and AMS are self-administered and completed within 10 minutes. CSSAM-Q is more time consuming, requires an investigator to administer, and memory domain is biased in favour of specific professional training. No difference was found between the two groups in 6 of 8 biochemical tests. However, significant lower values (p<0.001) were found for DHEA-S and IGF-1 in the symptomatic group as compared with the non-symptomatic cohort.

CONCLUSIONS

This study confirms that newer, more complex tools perform similarly to the simpler ADAM questionnaire. The lack of correlation between the clinical picture and the most commonly used biochemical confirmatory tests, again, clearly points to the paramount importance of the clinical evaluation. An emphasis and reliance on serum T alone hinders the clinician's ability to manage testosterone deficiency syndromes (TDS).

3beta-HSD activates DHEA in the songbird brain

Dehydroepiandrosterone (DHEA) is an abundant circulating prohormone in humans, with a variety of reported actions on central and peripheral tissues. Despite its abundance, the functions of DHEA are relatively unknown because common animal models (laboratory rats and mice) have very low DHEA levels in the blood. Over the past decade, we have obtained considerable evidence from avian studies demonstrating that (1) DHEA is an important circulating prohormone in songbirds and (2) the enzyme 3beta-hydroxysteroid dehydrogenase/isomerase (3beta-HSD), responsible for converting DHEA into a more active androgen, is expressed at high levels in the songbird brain. Here, we first review biochemical and molecular studies demonstrating the widespread activity and expression of 3beta-HSD in the adult and developing songbird brain. Studies examining neural 3beta-HSD activity show effects of sex, stress, and season that are region-specific. Second, we review studies showing seasonal and stress-related changes in circulating DHEA in captive and wild songbird species. Third, we describe evidence that DHEA treatment can stimulate song behavior and the growth of neural circuits controlling song behavior. Importantly, brain 3beta-HSD and aromatase can work in concert to locally metabolize DHEA into active androgens and estrogens, which are critical for controlling behavior and robust adult neuroplasticity in songbirds. DHEA is likely secreted by the avian gonads and/or adrenals, as is the case in humans, but DHEA may also be synthesized de novo in the songbird brain from cholesterol or other precursors. Irrespective of its source, DHEA seems to be an important prohormone in songbirds, and 3beta-HSD is a key enzyme in the songbird brain.

New development in intracrinology of breast carcinoma: therapeutic horizons after aromatase inhibitors

Aromatase inhibitors have become the gold standard of endocrine therapy in postmenopausal patients with estrogen receptor-positive or estrogen-dependent breast carcinoma, replacing tamoxifen. However, it is true that there are some potential problems to be overcome or improved on regarding aromatase inhibitor treatment of breast cancer. This especially includes the presence of the estrogen receptor-positive patients who do not necessarily respond to aromatase inhibitors, may require other modes of endocrine therapy and develop resistance to aromatase inhibitor in their clinical course, and who may also need alternative modes of suppressing intratumoral estrogen signals or other intracellular signal pathways related to tumor progression or development. Intratumoral estrogen production from precursors present in circulation in an 'intracrine' manner is considered to play very important roles in the development and progression of estrogen receptor-positive breast cancer. The great majority of estrone in circulation is present as a sulfated form or estrone sulfate, and steroid sulfatase hydrolyzes circulating estrone sulfate to estrone in various human tissues in situ, which confers potent estrogenic actions. Estrone is subsequently reduced to 17β-estradiol by 17β-hydroxysteroid dehydrogenase type 1. Therefore, these two enzymes also play very important roles in intracrinology of estrogen in breast cancer in addition to intratumoral aromatase, and the potential inhibition of these two enzymes could lead to the development of a new mode of endocrine therapy based on intracrinology, which may overcome some of the problems above in aromatase inhibitor therapy. In this review, the potential advantages and pitfalls or problems associated with the inhibition of these two intratumoral enzymes in breast cancer patients will be discussed.

Hormonal regulation of longevity in mammals

Multiple biological and environmental factors impact the life span of an organism. The endocrine system is a highly integrated physiological system in mammals that regulates metabolism, growth, reproduction, and response to stress, among other functions. As such, this pervasive entity has a major influence on aging and longevity. The growth hormone, insulin-like growth factor-1 and insulin pathways have been at the forefront of hormonal control of aging research in the last few years. Other hormones, including those from the thyroid and reproductive system have also been studied in terms of life span regulation. The relevance of these hormones to human longevity remains to be established, however the evidence from other species including yeast, nematodes, and flies suggest that evolutionarily well-conserved mechanisms are at play and the endocrine system is a key determinant.

In rats, oral oleoyl-DHEA is rapidly hydrolysed and converted to DHEA-sulphate

Background

Dehydroepiandrosterone (DHEA) released by adrenal glands may be converted to androgens and estrogens mainly in the gonadal, adipose, mammary, hepatic and nervous tissue. DHEA is also a key neurosteroid and has antiglucocorticoid activity. DHEA has been used for the treatment of a number of diseases, including obesity; its pharmacological effects depend on large oral doses, which effect rapidly wanes in part because of its short half-life in plasma. Since steroid hormone esters circulate for longer periods, we have studied here whether the administration of DHEA oleoyl ester may extend its pharmacologic availability by keeping high circulating levels.

Results

Tritium-labelled oleoyl-DHEA was given to Wistar male and female rats by gastric tube. The kinetics of appearance of the label in plasma was unrelated to sex; the pattern being largely coincident with the levels of DHEA-sulfate only in females, and after 2 h undistinguishable from the results obtained using labelled DHEA gavages; in the short term, practically no lipophilic DHEA label was found in plasma. After 24 h only a small fraction of the label remained in the rat organs, with a different sex-related distribution pattern coincident for oleoyl- and free- DHEA gavages. The rapid conversion of oleoyl-DHEA into circulating DHEA-sulfate was investigated using stomach, liver and intestine homogenates; which hydrolysed oleoyl-DHEA optimally near pH 8. Duodenum and ileum contained the highest esterase activities. Pure hog pancreas cholesterol-esterase broke down oleoyl-DHEA at rates similar to those of oleoyl-cholesterol. The intestinal and liver esterases were differently activated by taurocholate and showed different pH-activity patterns than cholesterol esterase, suggesting that oleoyl-DHEA can be hydrolysed by a number of esterases in the lumen (e.g. cholesterol-esterase), in the intestinal wall and the liver.

Conclusion

The esterase activities found may condition the pharmacological availability (and depot effect) of orally administered steroid hormone fatty acid esters such as oleoyl-DHEA. The oral administration of oleoyl-DHEA in order to extend DHEA plasma availability has not been proved effective, since the ester is rapidly hydrolysed, probably in the intestine itself, and mainly converted to DHEA-sulfate at least in females.

Expression of steroidogenic enzymes and synthesis of sex steroid hormones from DHEA in skeletal muscle of rats

The functional importance of sex steroid hormones (testosterone and estrogens), derived from extragonadal tissues, has recently gained significant appreciation. Circulating dehydroepiandrosterone (DHEA) is peripherally taken up and converted to testosterone by 3beta-hydroxysteroid dehydrogenase (HSD) and 17beta-HSD, and testosterone in turn is irreversibly converted to estrogens by aromatase cytochrome P-450 (P450arom). Although sex steroid hormones have been implicated in skeletal muscle regulation and adaptation, it is unclear whether skeletal muscles have a local steroidogenic enzymatic machinery capable of metabolizing circulating DHEA. Thus, here, we investigate whether the three key steroidogenic enzymes (3beta-HSD, 17beta-HSD, and P450arom) are present in the skeletal muscle and are capable of generating sex steroid hormones. Consistent with our hypothesis, the present study demonstrates mRNA and protein expression of these enzymes in the skeletal muscle cells of rats both in vivo and in culture (in vitro). Importantly, we also show an intracellular formation of testosterone and estradiol from DHEA or testosterone in cultured muscle cells in a dose-dependent manner. These findings are novel and important in that they provide the first evidence showing that skeletal muscles are capable of locally synthesizing sex steroid hormones from circulating DHEA or testosterone.

Redox reactions of dehydroepiandrosterone and its metabolites in differentiating 3T3-L1 adipocytes: A liquid chromatographic-mass spectrometric study

Dehydroepiandrosterone is known to depress fatty acid formation in differentiating 3T3-L1 adipocytes. The metabolism of dehydroepiandrosterone and four of its natural metabolites in differentiating adipocytes was studied by liquid chromatography-mass spectrometry. Adipocytes rapidly converted dehydroepiandrosterone to androst-5-ene-3beta,17beta-diol. 7alpha-Hydroxy-DHEA was interconverted with 7-oxo-DHEA and 7beta-hydroxy-DHEA and the corresponding 17beta reduced products. Dehydroepiandrosterone and its derivatives were detected only in the culture medium suggesting that dehydroepiandrosterone is metabolized via enzymes located in close proximity to, or that are integral parts of the cell membrane. Alternatively, there may be efficient mechanisms at play for extrusion of the steroids to the aqueous media rather than being retained in the lipid-rich cell. An interesting aspect of the study was finding androstenediol as the major metabolite of dehydroepiandrosterone. Androst-5-ene-3beta,17beta-diol has been implicated in prostate cancer. The contribution of adipose cells to the circulating supply of androst-5-ene-3beta,17beta-diol may therefore be considered in managing prostate cancer.

Androgen Status of the Nonautoimmune Dry Eye Subtypes

PURPOSE

To evaluate androgen levels of patients diagnosed with nonautoimmune dry eye, either with meibomian gland dysfunction (MGD) or without MGD (non-MGD), and normal control subjects. This is a prospective, comparative, case-control study.

METHODS

Sixty-four (32 men and 32 women) subjects were enrolled for each of the three diagnostic groups. All dry eye patients were symptom positive. Nonfasting testosterone (T), sex hormone-binding globulin, serum albumin, dehydroepiandrosterone (DHEA), and DHEA sulphate levels of all study participants were determined using either automated immunoenzymatic assay, or standard radioimmunoassay. Analysis of variance was used to compare androgen levels among the three diagnostic groups in a gender-based design, followed by post-hoc multiple comparisons with the Tukey honestly significant difference test.

RESULTS

Mean T levels in men and women of the three diagnostic groups were not significantly different (p = 0.808, p = 0.156, respectively; ANOVA). Statistical analyses of the three diagnostic groups revealed a significant difference for men and women in bioavailable T levels (p = 0.002, p = 0.014, respectively; ANOVA), DHEA levels (p = 0.009, p = 0.004, respectively; ANOVA), and DHEA sulphate levels (p = 0.001, p = 0.001, respectively; ANOVA), whereas there was no statistically significant difference between non-MGD dry eye patients and controls for any of the measured androgen levels according to the post-hoc tests.

CONCLUSION

This study demonstrates that the androgen pool of nonautoimmune dry eye patients with MGD is significantly depleted compared with that of non-MGD and control cases.

New development in intracrinology of breast carcinoma

Intratumoral metabolism and synthesis of estrogens as a result of the interactions of various enzymes are considered to play very important roles in the pathogenesis and development of hormone dependent breast carcinoma. Among these enzymes, intratumoral aromatase plays as important role converting serum androgens to estrogens in situ, and serves as a source of estrogen, especially in postmenopausal patients with breast carcinoma. However, other enzymes such as the 17beta-hydroxysteroid dehydrogenase (17beta-HSD) isozymes, estrogen sulfatase (STS) and estrogen sulfotransferase, also play pivotal roles in intratumoral estrogen production. The 17beta-hydroxysteroid dehydrogenase (17beta-HSD) isozymes catalyze the interconversion of estradiol (E2) and estrone (E1), and thereby serve to modulate the tissue levels of bioactive E2 in human breast carcinoma. 17Beta-HSD type 1 catalyzes primarily the reduction of estrone (E1) to estradiol (E2), whereas 17beta-HSD type 2 catalyzes primarily the oxidation of E2 to E1. In human breast disease, 17beta-HSD type 1 is expressed in proliferative disease without atypia, atypical ductal hyperplasia, ductal carcinoma in situ and invasive ductal carcinoma. 17Beta-HSD type 2 has not been detected in any of these breast lesions. In addition, 17beta-HSD type 1 coexpression is significantly correlated with estrogen receptor status in invasive ductal carcinoma cases. These results indicate that breast carcinoma can effectively convert E1, produced as a result of in situ aromatization, to E2, a biologically potent estrogen, which exerts estrogenic actions on tumor cells through estrogen receptor, especially the alpha subtype in carcinoma cells. Therefore, inhibiting intratumoral 17beta-HSD type 1 is also considered to contribute to inhibition of cell proliferation by decreasing intratumoral estradiol. Estrogen sulfotransferase (EST; SULT 1E1 or STE gene) sulfonates estrogens to inactive estrogen sulfates, while steroid sulfatase (STS) hydrolyzes estrone sulfate (E1-S) to estrone. EST immunoreactivity was recently demonstrated to be significantly associated with a decreased risk of recurrence or improved prognosis by both uni- and multivariate analyses. STS immunoreactivity was significantly associated with an increased risk of recurrence by univariate analysis. These findings also suggest that EST and STS plays important roles in regulation of in situ estrogen production, and EST especially is a potent prognostic factor in human breast carcinoma. Therefore, the inhibition of intratumoral STS might also serve as an endocrine therapy in postmenopausal patients. It is also important to note that the status of intratumoral aromatase, 17beta-HSD type 1, EST and STS in human breast cancer tissues is variable and not necessarily correlated with each other, which suggests different potential sources of intratumoral estrogens among individual patients with breast cancer. These findings indicate that there are patients who could benefit more from inhibition of these intratumoral enzymes rather than aromatase inhibition as an endocrine therapy. Therefore, it will become very important to examine the intratumoral levels of 17beta-HSD type 1 and STS in the resected specimens of human breast carcinoma as potential targets of novel endocrine therapy in the near future.

Dehydroepiandrosterone (DHEA) is an anabolic steroid like dihydrotestosterone (DHT), the most potent natural androgen, and tetrahydrogestrinone (THG)

We have recently taken advantage of the unique power of DNA microarrays to compare the genomic expression profile of tetrahydrogestrinone (THG) with that of dihydrotestosterone (DHT), the most potent natural androgen, thus clearly demonstrating that THG is an anabolic steroid. In 2004, the U.S. Controlled Substances Act has been modified to include androstenedione (4-dione) as an anabolic steroid. However, despite the common knowledge that dehydroepiandrosterone (DHEA) is the precursor of testosterone, DHEA has been excluded from the list of anabolic steroids. We thus used the same DNA microarray technology to analyze the expression profile of practically all the 30,000 genes of the mouse genome modulated by DHEA and DHT in classical androgen-sensitive tissues. Daily subcutaneous injections of DHT (0.1mg) or DHEA (3mg) for 1 month in gonadectomized C57BL6/129 SV mice increased ventral prostate, dorsal prostate, seminal vesicle and preputial gland weight (p<0.01 for all tissues). As early as 24h after single injection of the two steroids, 878, 2681 and 14 probe sets were commonly stimulated or inhibited (p<0.01, change> or =30%), in the prostate (ventral+dorsal), seminal vesicles and preputial glands, respectively, compared to tissues from gonadectomized control animals. After 7 days of daily treatment with DHEA and DHT, 629, 919 and 562 probe sets were commonly modulated in the same tissues while after 27 days of treatment, 1195, 5127 and 2883 probe sets were modulated, respectively. In analogy with the data obtained with THG, the present microarray data provide an extremely precise and unquestionable genomic signature and proof of the androgenic/anabolic activity of DHEA. Such data add to the literature showing that DHEA is transformed into androgens in the human peripheral tissues as well as in laboratory animal species, including the monkey, thus exerting potent androgenic/anabolic activity. The present microarray approach to identify anabolic compounds is applicable to all potential androgenic/anabolic compounds.

Endocrine effects of oral dehydroepiandrosterone in men with HIV infection: a prospective, randomized, double-blind, placebo-controlled trial

Dehydroepiandrosterone (DHEA) is commonly used by HIV-infected men, but its endocrine effects in this population are not well defined. We conducted an 8-week randomized, placebo-controlled trial to determine the effects of escalating doses (100-400 mg/d) of DHEA on the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axes, and on a number of metabolic parameters in 69 HIV-positive men (31 in DHEA-treated group, 38 in placebo group). High-dose (250 microg) corticotropin and luteinizing hormone-releasing hormone stimulation tests were carried out in all subjects. Fifty-four subjects (26 in the DHEA-treated group and 28 in the placebo group) also underwent optional corticotropin-releasing hormone test, and 67 subjects (31 in DHEA-treated group and 36 in placebo group) underwent optional low-dose (1 microg) corticotropin stimulation test. All tests were performed at baseline and at the end of week 8. Repeated-measures analysis of variance was used to analyze the data. We observed significant increases in circulating levels of DHEA, DHEA-sulfate, free testosterone, dihydrotestosterone, androstenedione, and estrone, and a decline in the serum concentration of sex hormone-binding globulin in the DHEA-treated group but not in the placebo group (P < .001). There were no differences between the groups in other endocrine or metabolic parameters or in the results of the stimulation tests. In conclusion, oral DHEA therapy in HIV-positive men significantly increases circulating levels of DHEA and DHEA-sulfate, free testosterone, dihydrotestosterone, androstenedione, and estrone and suppresses circulating concentration of sex hormone-binding globulin. Long-term studies are needed to assess the clinical significance of these hormonal changes in subjects with HIV infection receiving oral DHEA therapy.

The biological actions of dehydroepiandrosterone involves multiple receptors

Dehydroepiandrosterone has been thought to have physiological functions other than as an androgen precursor. The previous studies performed have demonstrated a number of biological effects in rodents, such as amelioration of disease in diabetic, chemical carcinogenesis, and obesity models. To date, activation of the peroxisome proliferators activated receptor alpha, pregnane X receptor, and estrogen receptor by DHEA and its metabolites have been demonstrated. Several membrane-associated receptors have also been elucidated leading to additional mechanisms by which DHEA may exert its biological effects. This review will provide an overview of the receptor multiplicity involved in the biological activity of this sterol.

Identification of Steroidogenic Enzyme mRNAs in the Human Lacrimal Gland, Meibomian Gland, Cornea, and Conjunctiva

PURPOSE

Sex steroids exert a significant influence on the health and well-being of the ocular surface and adnexa. These hormones affect multiple aspects of the lacrimal and meibomian glands, conjunctiva, and cornea, and have been linked to the development of many ocular surface pathologies. We hypothesize that these hormone actions, as in other tissues, occur predominantly after the local synthesis of androgens and estrogens from adrenal precursors. To begin to test this hypothesis, we analyzed whether human ocular surface and adnexal tissues and cells contain the steroidogenic enzyme mRNAs necessary for the intracrine synthesis and metabolism of sex steroids.

METHODS

Total RNA was isolated from human lacrimal and meibomian glands and immortalized corneal and conjunctival epithelial cells. Samples were reverse transcribed to cDNA and analyzed for the presence of enzyme mRNAs by real-time PCR. Positive and negative controls included human placental cDNA and the absence of template, respectively.

RESULTS

Our results show that human lacrimal and meibomian glands and corneal and conjunctival epithelial cells contain the mRNAs for steroid sulfatase, 3beta-hydroxysteroid dehydrogenase (HSD)-Delta-Delta-isomerase type 1, 17beta-HSD types 1 and 3, aromatase, and glucuronosyltransferase. In contrast, only lacrimal and meibomian tissues appeared to contain detectable mRNA for sulfotransferase.

CONCLUSIONS

If the corresponding mRNAs are translated, our results indicate that human ocular surface and adnexal tissues contain the enzymatic machinery necessary for the intracrine synthesis and metabolism of sex steroids.

Dehydroepiandrosterone, androgens and the mammary gland

Mainly through the transformation of dehydroepiandrosterone (DHEA) into androgens in peripheral tissues by intracrine mechanisms, women synthesize at least two-thirds of the androgens found in men. Such data strongly suggest that androgens exert very important but so far underestimated physiological functions in women, including in the breast. In fact, the mammary gland possesses all the enzymatic machinery required to transform DHEA into both androgens and estrogens, although androgens are the predominant steroids synthesized from DHEA in the mammary gland. Early clinical studies have shown beneficial effects of androgens on breast cancer which are comparable to those observed with other hormonal therapies. In fact, a long series of preclinical and clinical data clearly indicate that proliferation of both the normal mammary gland and breast cancer results from the balance between the stimulatory effect of estrogens and the inhibitory effect of androgens. Moreover, the data showing the additive inhibitory effects of antiestrogens and androgens suggest that taking advantage of the inhibitory effect of androgens on breast cancer proliferation could well improve the efficacy of the currently used estrogen deprivation therapies for the treatment and prevention of breast cancer, the best and most physiological candidate being DHEA that limits the androgenic exposure to the tissues which possess the required enzymatic intracrine machinery.

Controversies about HRT--lessons from monkey models

Lessons from monkey models contribute significantly to a better understanding of the controversies in reconciling the differences in postmenopausal hormone treatment outcomes between observational and randomized trial data. Monkey studies brought attention to premenopausal estrogen deficiency with resulting premature coronary artery atherosclerosis. Recently, those monkey studies were confirmed for premenopausal women in the NHLBI-sponsored Women's Ischemia Syndrome Evaluation (WISE) Study. Monkey studies have provided convincing evidence for the primary prevention of coronary artery atherosclerosis when estrogens are administered soon after the development of estrogen deficiency. Equally convincing are the data from monkey studies indicating the total loss of these estrogens beneficial effects if treatment is delayed for a period equal to six postmenopausal years for women. An attempt has been made using the monkey model to identify the hormone treatment regimen most effective in preventing the progression of coronary artery atherosclerosis. By a substantial margin, the most effective approach is that of using estrogen containing oral contraceptive during the perimenopausal transition, followed directly by hormone replacement therapy postmenopausally. Because of similarities between human and nonhuman breast, monkeys have had a major role in clarifying controversies surrounding the breast cancer risk of estrogen only versus estrogen plus progestin therapies. The results of monkey studies suggest little or no effects of estrogen only treatment; whereas, estrogen+progestin clearly increases breast cancer risk.

The role of androgens in hormone replacement therapy

In recent years, increased attention to women's sexual health has propelled basic scientific research and clinical trials investigating treatment paradigms for improving sexual well-being. As the prevalence of female sexual dysfunction has become manifest, knowledge of the intricate pathophysiological role of androgens in maintaining sexual function has fostered a clearer understanding of the effect of age on androgen status, the role of androgens in the postmenopausal ovary, and aetiological mechanisms of androgen insufficiency in premenopausal and postmenopausal women. Understanding the long-term safety and efficacy of physiological androgen replacement and the development of sensitive testosterone assays for specific use in women will better characterise women who are most likely to respond to androgen therapy and, thereby, optimise their quality of life.

Fluorometric assay for alcohol sulfotransferase

A sensitive fluorometric assay was developed for alcohol sulfotransferase (AST). This was the first continuous fluorometric assay reported for AST. It used 3'-phosphoadenosine 5'-phosphosulfate regenerated from 3-phosphoadenosine 5'-phosphate by a recombinant phenol sulfotransferase (PST) using 4-methylumbelliferyl sulfate as the sulfuryl group donor. The recombinant PST did not use the alcohol substrate under the designed condition, and the sensitivity for AST activity was found to be comparable to that of radioactive assay as reported in the literature. The change of fluorescence intensity of 4-methylumbelliferone corresponded directly to the amount of active AST and was sensitive enough to measure nanogram or picomole amounts of the enzyme activity. This fluorometric assay was used to determine the activities of AST as purified form and in crude extracts of pig liver, rat liver, and Escherichia coli. Some properties of human dehydroepiandrosterone sulfotransferase were determined by this method and were found to be comparable to published data. Under similar assay conditions, the contaminated activities of arylsulfatase in crude extracts were also determined. This method not only is useful for the routine and detailed kinetic study of this important class of enzymes but also has the potential for the development of a high-throughput procedure using microplate reader.

Effects of dehydroepiandrosterone, Premarin and Acolbifene on histomorphology and sex steroid receptors in the rat vagina

To assess the specific estrogenic and/or androgenic effects of a potential novel hormone replacement therapy, we have examined the morphology of the rat vagina 9 months after ovariectomy (OVX) and treatment of OVX animals with dehydroepiandrosterone (DHEA), conjugated estrogens Premarin and the selective estrogen receptor modulator Acolbifene. OVX led to atrophy and inflammatory changes while Acolbifene reduced the inflammation incidence and induced mucification of the vaginal epithelium. Premarin induced a typical keratinized stratified squamous epithelium while DHEA induced stimulation of the vaginal epithelium, with mucous cells typical of an androgenic effect, combined with increased collagen fiber compactness of the lamina propria. On the other hand, after OVX, the vaginal muscle layer decreased by 46%, an effect which was 41 and 100% reversed by DHEA and Premarin, respectively. The present data show particularly interesting effects of DHEA on the three layers of the vaginal wall, namely a highly mucified epithelium, an increased muscularis thickness and increased collagen fiber compactness in the lamina propria. DHEA exerts both androgenic and estrogenic effects on the vaginal mucosa, thus providing a more physiological replacement therapy.

Adrenal corticosteroid biosynthesis, metabolism, and action

Adrenal corticosteroids are essential for life, and an appreciation of the mechanisms underpinning their synthesis, secretion, and mode of action in normal physiology is essential if the physician is to diagnose and treat patients who have Cushing's syndromes effectively. In each case, there have been clinically significant advances in the knowledge base over recent years, notably in the understanding of steroidogenesis, cortisol action, and metabolism. This article describes corticosteroid biosynthesis, metabolism, and action.

Dehydroepiandrosterone negatively regulates the p38 mitogen-activated protein kinase pathway by a novel mitogen-activated protein kinase phosphatase

Dehydroepiandrosterone-sulfate, the sulfated form of dehydroepiandrosterone, is the most abundant steroid in young adults, but gradually declines with aging. In humans, the clinical application of dehydroepiandrosterone targeting some collagen diseases, such as systemic lupus erythematosus, as an adjunctive treatment has been applied in clinical trial. Here, we report that dehydroepiandrosterone may negatively regulate the mitogen-activated protein kinase pathway in humans via a novel dual specificity protein phosphatase, DDSP (dehydroepiandrosterone-enhanced dual specificity protein phosphatase). DDSP is highly homologous to LCPTP/HePTP, a tissue-specific protein tyrosine phosphatase (PTP) which negatively regulates both ERK and p38-mitogen-activated protein kinase, and is transcribed from the PTPN7 locus by alternative splicing. Although previous reports have shown that the mRNA expression of the LCPTP/HePTP gene was inducible by extracellular signals such as T-cell antigen receptor stimulation, reverse transcribed (RT)-PCR experiments using specific sets of primers suggested that the expression of LCPTP/HePTP was constitutive while the actual inducible sequence was that of DDSP. Furthermore DDSP was widely distributed among different types of human tissues and specifically interacted with p38-mitogen-activated protein kinase. This inducible negative regulation of the p38-mitogen-activated protein kinase-dependent pathway may help to clarify the broad range of dehydroepiandrosterone actions, thereby aiding the development of new preventive or adjunctive applications for human diseases.