Mice lacking Mrp1 have reduced testicular steroid hormone levels and alterations in steroid biosynthetic enzymes

The multidrug resistance-associated protein 1 (MRP1/ABCC1) is a member of the ABC active transporter family that can transport several steroid hormone conjugates, including 17beta-estradiol glucuronide, dehydroepiandrosterone sulfate (DHEAS), and estrone 3-sulfate. The present study investigated the role that MRP1 plays in maintaining proper hormone levels in the serum and testes. Serum and testicular steroid hormone levels were examined in both wild-type mice and Mrp1 null mice. Serum testosterone levels were reduced 5-fold in mice lacking Mrp1, while testicular androstenedione, testosterone, estradiol, and dehydroepiandrosterone (DHEA) were significantly reduced by 1.7- to 4.5-fold in Mrp1 knockout mice. Investigating the mechanisms responsible for the reduction in steroid hormones in Mrp1-/- mice revealed no differences in the expression or activity of enzymes that inactivate steroids, the sulfotransferases or glucuronosyltransferases. However, steroid biosynthetic enzyme levels in the testes were altered. Cyp17 protein levels were increased by 1.6-fold, while Cyp17 activity using progesterone as a substrate was also increased by 1.4- to 2.0-fold in mice lacking Mrp1. Additionally, the ratio of 17beta-hydroxysteroid dehydrogenase to 3beta-hydroxysteroid dehydrogenase, and steroidogenic factor 1 to 3beta-hydroxysteroid dehydrogenase were significantly increased in the testes of Mrp1-/- mice. These results indicate that Mrp1-/- mice have lowered steroid hormones levels, and suggests that upregulation of steroid biosynthetic enzymes may be an attempt to maintain proper steroid hormone homeostasis.

Relation of left ventricular ejection fraction and functional capacity with metabolism and inflammation in chronic heart failure with reduced ejection fraction (from the MIMICA Study)

Catabolism and inflammation play a role in the physiopathology of heart failure with reduced ejection fraction and are more pronounced in the advanced stages of the disease. Our aim was to demonstrate that in patients with stable heart failure with reduced ejection fraction adequately treated, a direct relation exists between functional impairment, as evaluated by left ventricular ejection fraction (LVEF) and the 6-minute walking distance (6MWD), and catabolic and inflammatory markers. In 151 outpatients with heart failure and a LVEF of < or =40% (median age 64 years, LVEF 29%, and 6MWD 290 m) we measured the laboratory and body composition parameters that indicate directly or indirectly inflammatory activation, anabolic-catabolic balance, and nutritional status. We performed an analysis stratified by quartiles of LVEF and 6MWD and linear regression analysis to explore our hypothesis. In the linear regression analysis, after adjusting for age, gender, and etiology, LVEF was not related to the metabolic, inflammatory, or nutritional parameters. The 6MWD was directly related to albumin (p = 0.002) and log transformation of dehydroepiandrosterone (p = 0.013) and inversely to adiponectin (p = 0.001) and the log-transformation of high-sensitivity C-reactive protein (p = 0.037). In conclusion, in a population with stable heart failure with reduced ejection fraction, the 6MWD was related to the degree of inflammatory activity and catabolism, but LVEF was not. Even a slightly diminished functional capacity implies underlying inflammation and catabolic activation.

Dehydroepiandrosterone to induce murine models for the study of polycystic ovary syndrome

During the last decade a battery of animal models used for the study of polycystic ovary syndrome (PCOS) have allowed a focus on different aspects of the pathology. Since dehydroepiandrosterone (DHEA) was found to be one of the most abundant circulating androgens in women with PCOS, a rodent model showing the salient features found in women with PCOS was developed by the injection of DHEA. Although insulin-sensitizing agents, such as biguanides, are clinically used in the treatment of diabetes and PCOS, the complete understanding of their mechanisms of action remains unknown. The present review discusses the molecular mechanisms involved in the development of PCOS by using the DHEA-PCOS murine model and analyzes the role of the biguanide metformin as treatment.

46,XX DSD: the masculinised female

The 46,XX disorders of sex development (DSDs) cause virilisation or masculinisation of the female foetus. The final common pathway of all 46,XX DSDs is excess dihydrotestosterone (DHT) or potent foreign androgen in the genital tissue during the critical period of sexual differentiation. Whereas the foetal testis is source of androgen in the male, it is the foetal adrenal that produces the DHT precursors in the female. By understanding the principles of human steroid biosynthesis, the pathogenesis of each disorder may be logically deduced, and treatment strategies are rationally constructed. In practice, however, therapies for many of these diseases are fraught with complications and caveats, and current approaches leave much room for improvement. This review discusses these diseases, their pathogenesis and approaches to therapy. We emphasise areas where improved treatments are sorely needed.

Neuroimmunomodulatory steroids in Alzheimer dementia

Though pathobiochemical and neurochemical changes and accompanied morphological alterations in Alzheimer dementia are well known, the triggering mechanisms, if any, remain obscure. Important factors influencing the development and progression of Alzheimer disease include hormonal steroids and their metabolites, some of which may serve as therapeutic agents. This review focusses on major biochemical alterations in the brain of Alzheimer patients with respect to the involvement of steroids. It includes their role in impairment of fuel supply and in brain glycoregulation, with especial emphasis on glucocorticoids and their counter-regulatory steroids as dehydroepiandrosterone and its metabolites. Further, the role of steroids in beta-amyloid pathology is reviewed including alterations in tau-protein(s) phosphorylation. The (auto)immune theory of Alzheimer dementia is briefly outlined, pointing to the possible involvement of steroids in brain ageing, immunosenescence and neuronal apoptosis. Some effects of steroids are briefly mentioned on the formation and removal of reactive oxygen species and their effect on calcium flux and cytotoxicity. The recent biochemical research of Alzheimer disease focusses on molecular signalling at which steroids also take part. New findings may be anticipated when the mosaic describing the molecular mechanisms behind these events becomes more complete.

Testosterone synthesized in cultured human SZ95 sebocytes derives mainly from dehydroepiandrosterone

Human sebaceous gland possesses all the steroidogenic enzymes required for androgen synthesis. It remains unclear whether the testosterone produced in situ mainly derives from circulating dehydroepiandrosterone (DHEA) or from de novo synthesis utilizing serum cholesterol. Using testosterone radioimmunoassay, we found that testosterone was barely detectable in the supernatant of cultured human SZ95 sebocytes when cholesterol was added alone, indicating a low basal expression of steroidogenic acute regulatory protein (StAR) in SZ95 cells. Human chorionic gonadotropin and fibroblast growth factor-9 were as potent as forskolin in activating StAR to enhance testosterone production, while interleukin-1 beta, dexamethasone, insulin and insulin-like growth factor-1 showed no stimulatory effect. A two-fold increase of testosterone production was observed in supplementation of DHEA as compared to pregnenolone, progesterone or 17 alpha-hydroxyprogesterone. Based on our findings, testosterone synthesized in cultured sebocytes derived mainly from DHEA and inhibition of 3beta-hydroxysteroid dehydrogenase and 17beta-hydroxysteroid dehydrogenase may be a new target of androgen suppression for acne treatment.

Acute exercise activates local bioactive androgen metabolism in skeletal muscle

Androgens, such as testosterone, play important roles in regulation of diverse physiological process of target tissues. Recently, we reported that steroidogenic enzymes exist in skeletal muscle and regulate local production of testosterone in response to exercise. Testosterone is transformed into a bioactive androgen metabolite, dihydrotestosterone (DHT) by 5alpha-reductase. However, it is unclear whether exercise stimulates local bioactive androgen metabolism in the skeletal muscle in both sexes. In the present study, we examined sex differences in the levels of dehydroepiandrosterone (DHEA), free testosterone, DHT, and steroidogenesis-related enzymes 5alpha-reductase and androgen receptor (AR) in rat's skeletal muscle before and after a single bout of exercise. Basal muscular free testosterone and DHT levels were higher in males than females, whereas the levels of DHEA did not differ between the sexes. Muscular DHEA, free testosterone, and DHT levels were increased in both sexes after the exercise. There were no differences of 5alpha-reductase and AR transcripts and proteins between the sexes, and the expression of 5alpha-reductase was significantly increased in both sexes after the exercise. Finally, the expression of AR was significantly higher in female rats, but not in males after the exercise. These data suggest that acute exercise enhances the local bioactive androgen metabolism in the skeletal muscle of both sexes.

Day-to-day differences in cortisol levels and molar cortisol-to-DHEA ratios among working individuals

PURPOSE

The present study was carried out to determine day-to-day differences in cortisol levels and the molar cortisol-to-dehydroepiandrosterone (DHEA) ratio (molar C/D ratio) in working subjects.

MATERIALS AND METHODS

The cortisol and DHEA levels were measured from saliva samples collected 30 minutes after awakening for 7 consecutive days in full-time working subjects that worked Monday through Saturday. To determine the day-to-day differences within subjects, the collected data was analyzed using variance (ANOVA) for a randomized complete block design (RCBD).

RESULTS

The cortisol levels from samples collected 30 minutes after awakening on workdays were similar to each other, but were significantly different from the cortisol levels on Sunday. The DHEA levels were not significantly different between the days of week. The DHEA levels on Monday and Tuesday were relatively lower than the levels on the other weekdays. The DHEA levels on Thursday and Friday were relatively higher than the other days. The molar C/D ratios on Sunday were significantly lower than those on workdays. The molar C/D ratios on Monday and Tuesday were significantly higher than those on Wednesday or other workdays.

CONCLUSION

The cortisol levels and the molar C/D ratios demonstrate differences in adrenocortical activities between workdays and non-workdays, but the molar C/D ratio additionally represents differences in adrenocortical status between the first two workdays and other workdays. Thus, it is possible that the day-to-day differences in the cortisol levels and the molar C/D ratio represent the adrenal response to upcoming work-related stress.

Stimulation of Sigma-1 receptor by dehydroepiandrosterone ameliorates hypertension-induced kidney hypertrophy in ovariectomized rats

The incidence of chronic renal disease in women increases with aging, especially after menopause, suggesting that loss of sex hormones contributes to the development and progression of renal diseases. Recent studies revealed that decreased dehydroepiandrosterone (DHEA) levels are associated with endothelial dysfunction, renal injury and increased cardiovascular mortality in postmenopausal women. We here investigate the role of DHEA, also known as Sigma-1 receptor (Sigma-1R) agonist, on kidney injury induced by pressure overload (PO) after ovariectomy (OVX) and defined mechanisms underlying its protective action. Wistar rats subjected to bilateral OVX were further treated with abdominal aortic stenosis between the right and left renal arteries. DHEA (15 and 30 mg/kg) was administered orally once a day for 14 days starting from two weeks after aortic banding. Time course study indicated that the right kidney (RK) weight-to-body weight (BW) ratio increases time-dependently from one to four weeks along with increased mean arterial blood pressure (MABP) after banding in the abdominal aorta with no change in the left kidney (LK) weight-to-BW ratio. Similarly, we found significant time-dependent decrease in Sigma-1R expression in the RK with no changes in the LK. Administration of the Sigma-1R agonist, DHEA, significantly inhibited hypertension-induced increases in the RKW-to-BW ratio and increased expression of Sigma-1R in the RK. DHEA also attenuated PO-induced disturbance of heart rate and MABP. DHEA administration significantly restored PO-induced impaired endothelial nitric oxide synthase (eNOS) activity with concomitant increased phosphorylation of eNOS (Ser1179) and Akt activity with increased phosphorylation at Ser 473 and at Thr 308 in the RK. We here documented, for the first time, the potential role of Sigma-1R to protect the kidney from PO-induced injury in ovariectomized rats. DHEA administration protects hypertension-induced kidney injury via upregulation of Sigma-1R and stimulation of Akt-eNOS signaling in ovariectomized rats.

Dehydroepiandrosterone-induced proliferation of prostatic epithelial cell is mediated by NFKB via PI3K/AKT signaling pathway

Dehydroepiandrosterone (DHEA) is an endogenous steroid that is metabolized to androgens and/or estrogens in the human prostate. DHEA levels decline with age, and use of DHEA supplements to retard the aging process is of unproved effectiveness and safety. In this study, rat ventral prostatic epithelial cells were used to determine whether DHEA-modulated proliferation and prostate-specific antigen (PSA listed as KLKB1 in the MGI Database) production were mediated via the androgen receptor (AR) and its potential mechanism. We demonstrated that proliferation of prostatic epithelial cells and increase of PSA expression induced by DHEA were neutralized by Casodex or Ar siRNA, two specific AR blockers. DHEA stimulated Nfkb DNA binding activity, with this effect being blunted by Casodex or Ar siRNA. Moreover, the inhibition of the phosphatidylinositol 3-kinase (PI3K)/AKT nullified the effects of DHEA on NFKB activation. These findings suggested that DHEA stimulated normal prostatic epithelial cell proliferation, and AR is involved in DHEA-induced PSA expression in normal prostatic epithelial cells. This stimulation effect induced by DHEA is mediated by the activation of NFKB via PI3K/AKT pathway.

Hypocortisolism in the South African angora goat: the role of 3betaHSD

South African Angora goats are susceptible to cold stress, due to their inability to produce sufficient levels of cortisol. During adrenal steroidogenesis the production of cortisol relies on the activity of two key enzymes, namely cytochrome P450 17alpha-hydroxylase and 3beta-hydroxysteroid dehydrogenase. Cytochrome P450 17alpha-hydroxylase has previously been identified as a factor contributing to hypocortisolism in the South African Angora goat. In this comparative study, the catalytic activity of Angora and ovine 3beta-hydroxysteroid dehydrogenase, which differ by five amino acid residues, was characterized. The conversion of 17-hydroxypregnenolone and dehydroepiandosterone to their corresponding products, 17-hydroxyprogesterone and androstenedione, by the two enzymes differed significantly. The enzymes were subsequently co-expressed with Angora P450 17alpha-hydroxylase. Major differences were observed in pregnenolone metabolism with a significant reduction in the formation of the cortisol precursor, 17-hydroxyprogesterone, by cells expressing Angora 3beta-hydroxysteroid dehydrogenase, implicating 3beta-hydroxysteroid dehydrogenase as an additional factor contributing to hypocortisolism in the South African Angora goat.

Effects of chromium(III) picolinate on cortisol and DHEAs secretion in H295R human adrenocortical cells

Dietary chromium(III) picolinate (CrPic) effects on circulating steroid hormones have been reported in various experimental animals. However, direct effects of CrPic on adrenocortical steroidogenesis are uncertain. Therefore, the objective was to determine the effects of CrPic on cortisol and dehydroepiandrosterone sulfate (DHEAs) secretion from H295R cells. In experiment 1, a 24-h exposure to CrPic (0 to 200 microM) had both linear (p < 0.001) and quadratic (p < 0.001) effects on cortisol secretion from forskolin-stimulated cells with the highest cortisol secretion at 0.1 microM of CrPic and the lowest at 200 microM of CrPic. In experiment 2, a 48-h exposure to CrPic (200 microM) decreased cortisol (p < 0.07) release from forskolin-stimulated cells during a 24-h collection period. In experiment 3, a 48-h exposure to CrPic (100 microM) decreased cortisol (p < 0.05) and DHEAs (p < 0.01) from forskolin-stimulated cells during a 24-h sampling period. In experiment 4, a 24-h exposure to forskolin followed by a 24-h exposure to both forskolin and CrPic (100 and 200 microM) decreased both cortisol and DHEAs secretion (p < 0.01). This study suggests that at high concentrations, CrPic inhibits aspects of steroidogenesis in agonist-stimulated adrenocortical cells.

DHEA-Bodipy--a functional fluorescent DHEA analog for live cell imaging

The androgen dehydroepiandrosterone (DHEA) has been reported to protect neuronal cells against dysfunction and apoptosis. Several signaling pathways involved in these effects have been described but little is known about the intracellular trafficking of DHEA. We describe design, synthesis and characterization of DHEA-Bodipy, a novel fluorescent DHEA analog. DHEA-Bodipy proved to be a functional DHEA derivative: DHEA-Bodipy (i) induced estrogen receptor alpha-mediated gene activation, (ii) protected PC12 rat pheochromocytoma cells against serum-deprivation-induced apoptosis, and (iii) induced stress fibers and focal adhesion contacts in SH-SY5Y human neuroblastoma cells. DHEA-Bodipy bound rapidly and specifically to plasma membranes of living PC12 cells. We analyzed metabolism and trafficking of DHEA-Bodipy in human neuroblastoma cells. DHEA-Bodipy is the first functional fluorescent DHEA derivative suitable for live cell imaging of intracellular DHEA transport and localization.

Neuroendocrine and immunological correlates of chronic stress in 'strictly healthy' populations

BACKGROUND

Chronic stress has been associated with detrimental or maladaptive neuroendocrine and immunological changes.

OBJECTIVES

We assessed the neuroendocrine and immunological correlates of a realistic chronic stress experienced by strictly healthy caregivers of Alzheimer's disease patients and age-matched controls.

METHODS

We screened 330 caregivers and 206 non-caregivers according to the 'strictly healthy' conditions established by the SENIEUR protocol. Forty-one strictly healthy caregivers (60.56 +/- 16.56 years) and 33 non-stressed controls (60.27 +/- 14.11 years) were selected for this study. Salivary cortisol and dehydroepiandrosterone sulfate (DHEAS) were assessed at multiple points by radioimmunoassay. Peripheral T cell proliferation and cellular sensitivity to glucocorticoids (corticosterone and dexamethasone, DEX) were evaluated by colorimetric assays. We also examined the hypothalamic-pituitary-adrenal (HPA) axis response to the administration of a low-dose DEX in vivo.

RESULTS

The caregivers were significantly more stressed, anxious and depressed than non-caregivers (all p < 0.0001), in contrast to similar cortisol levels. Caregivers had reduced DHEAS levels (-32%, p < 0.0001), an increased cortisol/DHEAS ratio (39.7%, p < 0.0001) and impaired HPA axis response to DEX intake. Caregivers had a higher T cell proliferation (p < 0.0001) and increased sensitivity to glucocorticoids in vitro (p < 0.01) as compared to non-stressed controls.

CONCLUSIONS

Our results suggest that the maintenance of health in chronically stressed populations may be associated with both protective and detrimental neuroendocrine and immunological changes.

Sex differences in neuroactive steroid levels in the nervous system of diabetic and non-diabetic rats

Neuropathy and encephalopathy represent important complications of diabetes. Recent observations obtained in experimental models have suggested that, in male rats, neuroactive steroids are protective agents and that their levels in peripheral (PNS) and central (CNS) nervous system are strongly affected by the disease. It is interesting to highlight that incidence, progression and severity of diabetic neuropathy and diabetic encephalopathy are different in the two sexes. Consequently, it is important to determine the changes in neuroactive steroid levels in the PNS and the CNS of both males and females. To this aim, we have evaluated the levels of neuroactive steroids such as, pregnenolone, progesterone and its metabolites, testosterone and its metabolites, and dehydroepiandrosterone in different CNS regions (i.e., cerebral cortex, cerebellum and spinal cord) and in the sciatic nerve of control and diabetic (i.e., induced by streptozotocin) male and female rats. Data obtained by liquid chromatography-tandem mass spectrometry indicate that the levels of neuroactive steroids show sex and regional differences in control animals. Streptozotocin-induced diabetes resulted in a strong general decrease in neuroactive steroid levels, in both the PNS and the CNS. In addition, the effects of diabetes on neuroactive steroid levels also show sex and regional differences. These findings may have strong implications for the development of new sex-oriented therapies for the treatment of diabetic neuropathy and diabetic encephalopathy, based on the use of neuroactive steroids.

Androgens and sexual function: a placebo-controlled, randomized, double-blind study of testosterone vs. dehydroepiandrosterone in men with sexual dysfunction and androgen deficiency

PURPOSE

Supplemental administration of androgens has been advocated for men with sexual dysfunction (SD) and hypoandrogenism. The preponderance of evidence indicates that most delivery forms of testosterone (T) are effective but the role of dehydroepiandrosterone (DHEA) is controversial. A placebo-controlled, randomized trial of oral androgen (T versus DHEA) supplementation was carried out to determine their efficacy.

MATERIALS AND METHODS

Eighty-six men with SD and decreased levels of serum T and/or DHEA, participated in a study receiving oral T undecanoate (OTU) (n = 29) 80 mg twice daily, DHEA (n = 28) 50 mg twice daily, or placebo (n = 29). Outcomes included evaluation of sexual performance by the International Index of Erectile Function (IIEF), the Androgen Deficiency in the Aging Male (ADAM), Aging Male Symtom Scale (AMS), and Global Assessment Questionnaire (GAQ) questionnaires. Biochemical evaluations included measurement of T and DHEA, prolactin, gonadotropins, and PSA.

RESULTS

Seventy-nine men completed the study. There were no significant differences in outcomes as assessed by four different instruments: the ADAM, IIEF, AMS, and GAQ in regard to sexual interest or erectile function. Biochemically, a significant increase in serum DHEA between baseline and final visit was documented in the group receiving DHEA. The levels of T, on the other hand, increased insignificantly between entry and final visit in the T cohort. No biochemical changes were observed in the placebo group. Levels of PSA remained stable in all three groups.

CONCLUSIONS

This study did not suggest a clinical benefit of OTU or DHEA supplementation in men with hypoandrogenism and SD. The recommended dose of OTU may have been inadequate or poorly absorbed. Increased doses or an alternative T delivery form may result in a different response.

A novel hydroxysteroid-sulfating cytosolic sulfotransferase, SULT3 ST3, from zebrafish: identification, characterization, and ontogenic study

To establish the zebrafish as a model for investigating the drug metabolism through sulfation, we had embarked on establishing a complete repertoire of the zebrafish Phase II cytosolic sulfotransferases (SULTs). By searching the expressed sequence tag database, a zebrafish cDNA encoding a putative cytosolic sulfotransferase (SULT) was identified. Based on the sequence analysis, this zebrafish SULT was found to belong to the SULT3 gene family. The recombinant protein of the zebrafish SULT, designated SULT3 ST3, was expressed in and purified from BL21 (DE3) Escherichia coli cells transformed with the pGEX-2TK expression vector harboring SULT3 ST3 cDNA. Upon enzymatic characterization, purified SULT3 ST3 displayed sulfating activity toward hydroxysteroids, particularly pregnenolone and dehydroepiandrosterone (DHEA), as well as several drugs among various endogenous and xenobiotic compounds tested as substrates. The pH-dependence and kinetic constants of this enzyme with DHEA were determined. The regulatory effects of various divalent metal cations on the DHEA-sulfating activity of SULT3 ST3 were quantitatively evaluated. A reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed developmental stage-dependent expression of SULT3 ST3 during embryonic development and throughout the larval stage onto maturity. Collectively, these results suggest a possible involvement of the newly discovered SULT3 ST3 in the metabolism of hydroxysteroids and xenobiotics including drugs in zebrafish.

Prostate cancer stromal cells and LNCaP cells coordinately activate the androgen receptor through synthesis of testosterone and dihydrotestosterone from dehydroepiandrosterone

One of the mechanisms through which advanced prostate cancer (PCa) usually relapses after androgen deprivation therapy (ADT) is the adaptation to residual androgens in PCa tissue. It has been observed that androgen biosynthesis in PCa tissue plays an important role in this adaptation. In the present study, we investigated how stromal cells affect adrenal androgen dehydroepiandrosterone (DHEA) metabolism in androgen-sensitive PCa LNCaP cells. DHEA alone had little effect on prostate-specific antigen (PSA) promoter activity and the proliferation of LNCaP cells. However, the addition of prostate stromal cells or PCa-derived stromal cells (PCaSC) increased DHEA-induced PSA promoter activity via androgen receptor activation in the LNCaP cells. Moreover, PCaSC stimulated the proliferation of LNCaP cells under physiological concentrations of DHEA. Biosynthesis of testosterone or dihydrotestosterone from DHEA in stromal cells and LNCaP cells was involved in this stimulation of LNCaP cell proliferation. Androgen biosynthesis from DHEA depended upon the activity of various steroidogenic enzymes present in stromal cells. Finally, the dual 5alpha-reductase inhibitor dutasteride appears to function not only as a 5alpha-reductase inhibitor but also as a 3beta-hydroxysteroid dehydrogenase inhibitor in LNCaP cells. Taken together, this coculture assay system provides new insights of coordinate androgen biosynthesis under the microenvironment of PCa cells before and after ADT, and offers a model system for the identification of important steroidogenic enzymes involved in PCa progression and for the development of the corresponding inhibitors of androgen biosynthesis.

[Dihydroxylation of dehydroepiandrosterone in positions 7alpha and 15alpha by mycelial fungi]

The ability of 485 fungal strains is studied for catalysis of the process of 7alpha, 15alpha-dihydroxylation of dehydroepiandrosterone (DHEA, 3alpha-hydroxy-5-androstene-17-one), a key intermediate of the synthesis of physiologically active compounds. The ability for the formation of 3alpha, 7alpha, 15alpha-trihydoxy-5-androstene-17-one (7alpha, 15alpha-di-OH-DHEA) was found for the first time for representatives of 12 genera, eight families, and six orders of ascomycetes, eight genera, four families, and one order of zygomycetes, one genus, one family, and one order of basidiomycetes, and four genera of mitosporous fungi. The most active strains are found among genera Acremonium, Gibberella, Fusarium, and Nigrospora. In the process of transformation of DHEA (2 g/l) by strains of Fusarium oxysporum RKM F-1600 and FGibberella zeae BKM F-2600, the molar yield was 63 and 68%, respectively. Application of the revealed active strains of microorganisms opens prospects for the efficient production of key intermediates of synthesis of modern medical preparations.

Photoperiodic regulation of adrenal hormone secretion and aggression in female Syrian hamsters

Seasonal changes in the length of the daily photoperiod induce significant changes in social behavior. Hamsters housed in winter-like short photoperiods (SP) can express significantly higher levels of aggression than hamsters housed in long photoperiods (LP) that mimic summer. The mechanisms responsible for increasing aggressiveness in SP-exposed female hamsters are not well understood but may involve seasonal changes in the endocrine system. In experiment 1, the effects of SP exposure on the circulating levels of three adrenal hormones were determined. Short photoperiod exposure was found to significantly depress the circulating levels of cortisol and the adrenal androgen dehydropiandrosterone (DHEA) but significantly increased the circulating levels of the sulfated form of DHEA, DHEAS. Experiment 2 examined the effects of gonadal hormones on several different measures of aggression including its intensity in females housed in both long and short photoperiod. Exposure to SP resulted in high levels of aggression regardless of the endocrine state of the animal or the measure used to quantify aggression. In contrast, administration of estradiol to hamsters housed in LP significantly reduced aggression. The data of the present study support the hypothesis that SP-housed females are more aggressive than LP-housed females because SP exposure renders females insensitive to the aggression-reducing effects of ovarian hormones.

Studies on Baeyer-Villiger oxidation of steroids: DHEA and pregnenolone D-lactonization pathways in Penicillium camemberti AM83

Penicillium camemberti AM83 strain is able to carry out effective Baeyer-Villiger type oxidation of DHEA, pregnenolone, androstenedione and progesterone to testololactone. Pregnenolone and DHEA underwent oxidation to testololactone via two routes: through 4-en-3-ketones (progesterone and/or androstenedione respectively) or through 3beta-hydroxy-17a-oxa-d-homo-androst-5-en-17-one. Analysis of transformation progress of studied substrates as function of time indicates that the 17beta-side chain cleavage and oxidation of 17-ketones to d-lactones are catalyzed by two different, substrate-induced, BVMOs. In the presence of a C-21 substrate (pregnenolone or progesterone) induction of the enzyme catalyzing cleavage at 17beta-acetyl chain was observed, whereas DHEA and androstenedione induced activity of the BVMO responsible for the ring-D oxidation; 5-en-3beta-alcohol was a more effective inducer that the respective 4-en-3-ketone.

HDL-associated dehydroepiandrosterone fatty acyl esters: enhancement of vasodilatory effect of HDL

OBJECTIVE

Dehydroepiandrosterone (DHEA) and high-density lipoprotein (HDL) are both vascular relaxants. In the circulation, HDL transports DHEA fatty acyl esters (DHEA-FAEs), which are naturally occurring lipophilic derivatives of DHEA. We studied in isolated rat mesenteric arteries whether HDL-associated DHEA-FAE improves the vasodilatory effect of HDL.

METHODS AND RESULTS

To prepare DHEA-FAE-enriched HDL, we incubated DHEA with human plasma. After incubation, HDL was isolated, purified, and added in cumulative doses (0.1-125 microg/ml) to noradrenaline-precontracted rat arterial rings. DHEA-FAE-enriched HDL caused a dose-dependent relaxation (maximal 43+/-4%), which was significantly stronger than the effect of HDL from the control incubation without addition of DHEA (25+/-2%, p<0.001). When plasma incubation of DHEA was carried out in the presence of lecithin:cholesterol acyltransferase (LCAT) inhibitor, the relaxation response to HDL (25+/-3%) did not differ from the control HDL (p=0.98). Pretreatment of the arterial rings with nitric oxide synthase (NOS) antagonist impaired the relaxation response to DHEA-FAE-enriched HDL (43+/-4% vs. 30+/-3%, p=0.008). Similar experiments were performed with 17beta-estradiol (E(2)). Compared to control HDL, E(2)-FAE-enriched HDL induced slightly but non-significantly stronger relaxation.

CONCLUSIONS

DHEA-FAE-enriched HDL was a stronger vasodilator than native HDL, and vascular relaxation was in part mediated by NOS, suggesting that DHEA-FAE may improve HDL's antiatherogenic function.

Specific estradiol biosynthetic pathway in choriocarcinoma (JEG-3) cell line

Estradiol (E2) plays a crucial role in all reproduction processes. In the placenta, it is well recognized that E2 is synthesized from fetal dehydroepiandrosterone sulfate (DHEAS). However, there is some controversy about the biosynthetic pathway involved, some authors suggest that E2 is produced by aromatization of testosterone (T), while others suggest that E2 is produced by the conversion of estrone (E1) into E2 by type 1 17beta-HSD, subsequent to the aromatization of 4-androstenedione (4-dione) into E1. In the present report, using the precursor [(14)C]DHEA, inhibitors of steroidogenic enzymes (chemical inhibitors and siRNA) and a choriocarcinoma (JEG-3) cell line that expresses all the enzymes necessary to transform DHEA into E2, we could determine the sequential steps and the specific steroidogenic enzymes involved in the transformation of DHEA into E2. Quantification of mRNA expression levels using real-time PCR, strongly suggests that type 1 3beta-hydroxysteroid dehydrogenase (3beta-HSD1), aromatase and type 1 17beta-HSD (17beta-HSD1) that are highly expressed in JEG-3 cells are the enzymes responsible for the transformation of DHEA into E2. Analysis of the intermediates produced in the absence and presence of 3beta-HSD, aromatase and 17beta-HSD1 inhibitors permits to determine the following sequential steps: DHEA is transformed into 4-dione by 3beta-HSD1, then 4-dione is aromatized into E1 by aromatase and E1 is finally transformed into E2 by 17beta-HSD1. Our data are clearly in favor of the pathway in which the step of aromatization precedes the step of reduction by 17beta-HSD.

24-dehydrocholesterol reductase/seladin-1: a key protein differentially involved in adrenocorticotropin effects observed in human and rat adrenal cortex

DHCR24 (24-dehydrocholesterol reductase), or seladin-1, is one of the most expressed genes in the adrenal gland. Because the rat and human adult adrenal cortex differ in their respective functional properties, the aim of the present study was to verify whether seladin-1 may be differentially involved in basal and ACTH-stimulated steroidogenesis and oxidative stress management. Seladin-1 expression was predominantly observed in both human and rat zona fasciculata, with a predominant cytoplasmic localization in human cells and a nucleo-cytoplasmic distribution in rat cells. In human fasciculata cells, localization of the protein was primarily associated with the endoplasmic reticulum. Although its expression was increased by ACTH, its intracellular localization was not altered by ACTH treatment (10 nm) or by the seladin-1 inhibitor U18666A (75 nm). Preincubation with U18666A did not modify the ACTH-induced increase in cortisol secretion but abolished the ACTH-induced increase in dehydroepiandrosterone secretion. In rat fasciculata cells, ACTH induced a massive redistribution of seladin-1 from the cytoplasm (cis-Golgi apparatus) to the nucleus, which was inhibited by preincubation with U18666A. Preincubation with U18666A also decreased ACTH-induced seladin-1 and 11beta-hydroxylase protein expression as well as corticosterone production, increased ACTH-induced ROS production but decreased ACTH-induced expression of the detoxifying protein aldo-ketoreductase 1b7. Thus, protection against acutely elevated ACTH-induced oxidative stress in rat fasciculata cells is correlated with nuclear relocalization of seladin-1 and its effects on cellular detoxifying machinery. Altogether, these results indicate that seladin-1 expression and intracellular localization are correlated with both the intensity and nature of ACTH-induced steroidogenesis and resultant oxidative stress.

Fasting-induced hepatic production of DHEA is regulated by PGC-1alpha, ERRalpha, and HNF4alpha

The transcriptional coactivator peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1alpha is involved in the coordinate induction of changes in gene expression in the liver that enable a homeostatic response to alterations in metabolic state, environmental cues, and nutrient availability. In exploring the specific pathways under PGC-1alpha regulation in the liver, we have made the surprising observation that this coactivator can induce the expression of CYP11A1 and CYP17A1, key rate-limiting enzymes involved in the initial steps of steroidogenesis. Both of these enzymes function to produce C(19)-steroids, converting cholesterol into pregnenolone, and then to dehydroepiandrosterone (DHEA). Estrogen-related receptor (ERR)-alpha mediates PGC-1alpha's induction of CYP11A1 and binds within the first intron of the CYP11A1 gene. Both ERR-alpha and hepatocyte nuclear factor-4alpha are required for PGC-1alpha-mediated induction of CYP17A1, and specific binding sites for these receptors have been identified in the regulatory regions of this gene. The potential physiological significance of these observations was highlighted in rats where fasting induced hepatic expression of PGC-1alpha and CYP17A1 and was associated with an increase in hepatic levels of DHEA. These data suggest that DHEA could be playing a role as an intracellular signaling molecule involved in modulating hepatic activity in response to fasting conditions.

The association between dehydroepiandosterone and frailty in older men and women

OBJECTIVES

to evaluate the association between dehydroepiandosterone (DHEA) and physical frailty in older adults.

DESIGN

cross-sectional analysis of baseline information from three separate studies in healthy older men, women and residents of assisted living.

SETTING

academic health centre in greater Hartford, CT, USA.

PARTICIPANTS

eight hundred and ninety-eight adults residing in the community or assisted living facility.

MEASUREMENTS

participants had measurement of frailty (weight loss, grip strength, sense of exhaustion, walking speed and physical activity) and serum DHEAS levels.

RESULTS

overall, 6% of the individuals in the study were classified as frail, 58% intermediate frail and 35% were not frail. In the bivariate analysis, there were differences between categories of frailty across age, gender and by DHEAS levels. In an ordinal logistic regression model, with frailty as a dependent measure, we found that age, DHEAS and interactions of age and BMI and DHEAS and BMI were predictive of more frailty characteristics.

CONCLUSION

we found an association between frailty and DHEAS levels. Whether the association is due to similar conditions resulting in lower DHEA levels and more susceptibility to frailty or whether lower DHEA levels have an impact on increasing frailty cannot be addressed by cross-sectional analysis. Gender did not impact the association between DHEAS and frailty, but obesity (BMI > 30 kg/m(2)) attenuated the association between higher DHEA levels and lower frailty status.

[Hormones and osteoporosis update. Adrenal androgen and bone]

DHEA is the major source for estrogen biosynthesis in postmenopausal women, since DHEA is converted to estrogen by aromatase in peripheral tissues. It has been suggested by animal models that a direct action of DHEA on bone tissue exists in addition to a biological action by estradiol converted from DHEA. Several RCTs (randomized, double-blinded, controlled trials) indicated that administration of daily 50 mg of DHEA increased bone mineral density (BMD) of lumbar spine or femoral neck. Increment of BMD was significant but small. The effect of DHEA on BMD is considered to be attributable to that of estradiol converted from DHEA, judging from analysis of serum steroid hormone concentrations.

Inactivating PAPSS2 mutations in a patient with premature pubarche

Dehydroepiandrosterone (DHEA) sulfotransferase, known as SULT2A1, converts the androgen precursor DHEA to its inactive sulfate ester, DHEAS [corrected], thereby preventing the conversion of DHEA to an active androgen. SULT2A1 requires 3'-phosphoadenosine-5'-phosphosulfate (PAPS) for catalytic activity. We have identified compound heterozygous mutations in the gene encoding human PAPS synthase 2 (PAPSS2) in a girl with premature pubarche, hyperandrogenic anovulation, very low DHEAS levels, and increased androgen levels. In vitro coincubation of human SULT2A1 and wild-type or mutant PAPSS2 proteins confirmed the inactivating nature of the mutations. These observations indicate that PAPSS2 deficiency is a monogenic adrenocortical cause of androgen excess.

[Dehydroepiandrosteron (DHEA) in the mechanisms of stress and depression]

There is growing interest in the role of Dehydroepiandrosteron (DHEA) in depression. To evaluate the validity of its administration in depression, the role of DHEA in the mechanism of depression and cardiovascular risk, as so the results of clinical trials must be considered. According to accessible literature, both concepts of depression--monoaminergic and glucocorticoid--are related. The key role may be played the impairment in regulatory function of monoaminergic, glucocorticoid and GABAergic receptors in the limbic area of the brain, caused by a genetic factor or acquired by stress. Consequently even weak stimulation could lead to inefficiency of the Limbic- hypothalamic-pituitary-adrenal (LHPA) homeostasis, with overproduction of cortisol. The excess of cortisol is facilitating the development of depression by damaging the limbic, especially hippocampal neurons. Furthermore, the cortisol is increasing cardiovascular risk by its atherogenic properties. The DHEA, because of its antiglucocorticoid activity is supposed to be a protective factor against depression and cardiovascular risk. Positive effects of administration of DHEA in depression were observed in clinical trials. However the results of estimation of DHEA and SDHEA in the blood of depressed patients were inconsistent. In animals, administration of high doses of DHEA was decreasing the experimental atherogenesis. However the investigation in numbered human populations showed correlation of increased level of DHEA with a decreased risk of cardiovascular disorder in men--but not in women. Further research on relation between depression, DHEA and cardiovascular risk, with special concern upon the differences in men and women is needed.

DHEA metabolism in prostate: For better or worse?

Dehydroepiandrosterone (DHEA) is commonly used in the USA as a nutritional supplement for antiaging, metabolic support or other uses. Investigations into understanding the effects of DHEA on human prostate cancer progression have posed more questions than answers and highlight the importance of communications between stromal and epithelial tuoitiuot elements within the prostate that contribute to the regulation of DHEA metabolism. Intracrine metabolism of DHEA to androgens (A) and/or estrogens (E) may occur in one cell compartment (stromal) which may release paracrine hormones or growth/inhibitory factors to the epithelial cells. Alternatively no metabolism of DHEA may occur, resulting in no harmful consequences of high levels of DHEA in prostate tissues. We herein review the tissue components involved and interactions with the prohormone, DHEA and/or resulting metabolites, including dihydrotestosterone (DHT) or 17beta-estradiol (E(2)) in an in vitro model of endocrine-immune-paracrine interactions within the prostate. This work raises questions and hypotheses concerning the role of DHEA in prostate in normal tissues, vs. preneoplastic tissues.

Hexose-6-phosphate dehydrogenase modulates the effect of inhibitors and alternative substrates of 11beta-hydroxysteroid dehydrogenase 1

Intracellular glucocorticoid reactivation is catalyzed by 11beta-hydroxysteroid dehydrogenase 1 (11beta-HSD1), which functions predominantly as a reductase in cells expressing hexose-6-phosphate dehydrogenase (H6PDH). We recently showed that the ratios of cortisone to cortisol and 7-keto- to 7-hydroxy-neurosteroids are regulated by 11beta-HSD1 and very much depend on coexpression with H6PDH, providing cosubstrate NADPH. Here, we investigated the impact of H6PDH on the modulation of 11beta-HSD1-dependent interconversion of cortisone and cortisol by inhibitors and alternative substrates. Using HEK-293 cells expressing 11beta-HSD1 or coexpressing 11beta-HSD1 and H6PDH, we observed significant differences of 11beta-HSD1 inhibition by natural and pharmaceutical compounds as well as endogenous hormone metabolites. Furthermore, we show potent and dose-dependent inhibition of 11beta-HSD1 by 7-keto-DHEA in differentiated human THP-1 macrophages and in HEK-293 cells overexpressing 11beta-HSD1 with or without H6PDH. In contrast, 7-ketocholesterol (7-KC) did not inhibit 11beta-HSD1 in HEK-293 cells, even in the presence of H6PDH, but inhibited 11beta-HSD1 reductase activity in differentiated THP-1 macrophages (IC(50) 8.1+/-0.9microM). 7-Keto-DHEA but not 7-KC inhibited 11beta-HSD1 in HEK-293 cell lysates. In conclusion, cellular factors such as H6PDH can significantly modulate the effect of inhibitors and alternative 7-oxygenated substrates on intracellular glucocorticoid availability.

Increased clearance of cortisol by 5beta-reductase in a subgroup of women with adrenal hyperandrogenism in polycystic ovary syndrome

OBJECTIVE

Increased peripheral metabolism of cortisol may explain compensatory ACTH-dependent adrenal steroidogenesis and hence hyperandrogenism in polycystic ovary syndrome (PCOS). Previous studies have described an increased 5alpha-reduction of cortisol or impaired regeneration of cortisol by 11beta-HSD1 in PCOS. However, these observations may be confounded by obesity. Moreover, the relationship between alterations in cortisol metabolism and the extent of adrenal androgen hyper-secretion in response to ACTH has not been established. This study aimed to examine the association between cortisol metabolism and ACTH-dependent adrenal hyperandrogenism in PCOS, independently of obesity.

DESIGN

We compared 90 PCOS women (age 18-45 yr) stratified by adrenal androgen responses to ACTH1-24 and 45 controls matched for age and body weight.

METHODS

PCOS women were stratified as normal responders (NR), intermediate responders (IR), and high responders (HR) to 250 microg ACTH1-24: NR (no.=27) had androstenedione and DHEA responses within 2 SD of the mean in controls; IR (no.=43) had DHEA responses >2 SD above controls; HR (no.=20) had both androstenedione and DHEA responses >2 SD above controls.

RESULTS

All groups were similar for age, body weight, and body fat distribution. Basal testosterone, androstenedione, and 5alpha-dihydrotestosterone plasma levels were similarly elevated among the 3 groups of PCOS compared with controls, whereas basal DHEA-S was higher in HR (2.8+/-1.2 microg/ml) and IR (2.4+/-1.1 microg/ml) than in NR (1.8+/-0.8 microg/ml) and controls (1.7+/-0.6 microg/ml). The HR group had the lowest basal plasma cortisol levels (101+/-36 ng/ml vs IR 135+/-42 ng/ml, NR 144+/-48 ng/ml, and controls 165+/-48 ng/ml; all p<0.01), but the greatest cortisol response to ACTH1-24 (Delta(60-0)cortisol 173+/-60 ng/ml vs IR 136+/-51 ng/ml, NR 114+/-50 ng/ml, and controls 127+/-50 ng/ml; all p<0.01), and the highest urinary excretion of total and 5beta-reduced cortisol metabolites (eg 5beta-tetrahydrocortisol/ cortisol ratio 25.2+/-15.3 vs IR 18.8+/-10.7, NR 19.7+/-11.4, and controls 17.2+/-13.7; all p<0.05). There were no differences in urinary excretion of 5alpha-reduced cortisol metabolites or in 5alpha-dihydrotestosterone/testosterone ratio between groups.

CONCLUSIONS

Adrenal androgen excess in PCOS is associated with increased inactivation of cortisol by 5beta-reductase that may lower cortisol blood levels and stimulate ACTH-dependent steroidogenesis.

Androgens and bone

Testosterone is the major gonadal sex steroid produced by the testes in men. Testosterone is also produced in smaller amounts by the ovaries in women. The adrenal glands produce the weaker androgens dehydroepiandrosterone, dehydroepiandrosterone sulfate, and androstenedione. These androgens collectively affect skeletal homeostasis throughout life in both men and women, particularly at puberty and during adult life. Because testosterone can be metabolized to estradiol by the aromatase enzyme, there has been controversy as to which gonadal sex steroid has the greater skeletal effect. The current evidence suggests that estradiol plays a greater role in maintenance of skeletal health than testosterone, but that androgens also have direct beneficial effects on bone. Supraphysiological levels of testosterone likely have similar effects on bone as lower levels via direct interaction with androgen receptors, as well as effects mediated by estrogen receptors after aromatization to estradiol. Whether high doses of synthetic, non-aromatizable androgens may, in fact, be detrimental to bone due to suppression of endogenous testosterone (and estrogen) levels is a potential concern that warrants further study.

Epimerase activity of the human 11beta-hydroxysteroid dehydrogenase type 1 on 7-hydroxylated C19-steroids

Cytochrome P4507B1 7alpha-hydroxylates dehydroepiandrosterone (DHEA), epiandrosterone (EpiA) and 5alpha-androstane-3beta,17beta-diol (Adiol). 11beta-Hydroxysteroid dehydrogenase type 1 (11beta-HSD1) interconverts 7alpha- and 7beta-forms. Whether the interconversion proceeds through oxido-reductive steps or epimerase activity was investigated. Experiments using [(3)H]-labelled 7beta-hydroxy-DHEA, 7beta-hydroxy-EpiA and 7beta-hydroxy-Adiol showed the (3)H-label to accumulate in the 7-oxo-DHEA trap but not in 7-oxo-EpiA or 7-oxo-Adiol traps. Computed models of 7-oxygenated steroids docked in the active site of 11beta-HSD1 either in a flipped or turned form relative to cortisone and cortisol. 7-Oxo-steroid reduction in 7alpha- or 7beta-hydroxylated derivatives resulted from either turned or flipped forms. 11beta-HSD1 incubation in H(2)(18)O medium with each 7-hydroxysteroid did not incorporate (18)O in 7-hydroxylated derivatives of EpiA and Adiol independently of the cofactor used. Thus oxido-reductive steps apply for the interconversion of 7alpha- and 7beta-hydroxy-DHEA through 7-oxo-DHEA. Epimerization may proceed on the 7-hydroxylated derivatives of EpiA and Adiol through a mechanism involving the cofactor and Ser(170). The physiopathological importance of this epimerization process is related to 7beta-hydroxy-EpiA production and its effects in triggering the resolution of inflammation.

DHEA lessens depressive-like behavior via GABA-ergic modulation of the mesolimbic system

Alterations in the levels of dehydroepiandrosterone (DHEA) in the brain can allosterically modulate gamma-aminobutyric-acid-type-A (GABA(A)R), N-methyl-D-aspartate (NMDAR), and Sigma-1 (sigma 1R) receptors. In humans, DHEA has antidepressive effects; however, the mechanism is unknown. We examined whether alterations in DHEA also occur in an animal model of depression, the Flinders-sensitive-line (FSL) rats, with the intention of determining the brain site of DHEA action and its antidepressant mechanism. We discovered that DHEA levels were lower in some brain regions involved with depression of FSL rats compared to Sprague-Dawley (SD) controls. Moreover, DHEA (1 mg/kg IP for 14 days)-treated FSL rats were more mobile in the forced swim test than FSL controls. In the NAc and VTA, significant changes were observed in the levels of the delta-subunit of GABA(A), but not of sigma 1R mRNA, in FSL rats compared to SD rats. The delta-subunit controls the sensitivity of the GABA(A)R to the neurosteroid. Indeed, treatment (14 days) of FSL rats with the GABA(A) agonist muscimol (0.5 mg/kg), together with DHEA (a negative modulator of GABA(A)), reversed the effect of DHEA on immobility in the swim test. Perfusion of DHEA sulfate (DHEAS) (3 nM and 30 nM for 14 days) into the VTA and NAc of FSL rats improved their performance in the swim test for at least 3 weeks post-treatment. Our results imply that alterations in DHEA are involved in the pathophysiology of depression and that the antidepressant action of DHEA is mediated via GABA(A)Rs in the NAc and VTA.

Synthesis of 3beta-hydroxy-androsta-5,7-dien-17-one from 3beta-hydroxyandrost-5-en-17-one via microbial 7alpha-hydroxylation

The synthesis of 3beta-hydroxy-androsta-5,7-dien-17-one from 3beta-hydroxy-androst-5-en-17-one (dehydroepiandrosterone, DHEA) via microbial 7alpha-hydroxylation has been accomplished. At the first stage, 3beta,7alpha-dihydroxy-androst-5-en-17-one was obtained in high yield (71.2%) using a strain of Gibberella zeae VKM F-2600, which was first applied for DHEA conversion. The further route included the substitution of 7alpha-hydroxyl group with chlorine followed by a dehydrochlorination stage, and required minimal purifications of the intermediate products. The steroids obtained at every step were characterized by TLC,1H NMR, MS, UV- and IR-spectrometry. The combination of microbial and chemical steps ensured 54.6% yield of the target 3beta-hydroxy-androsta-5,7-dien-17-one from DHEA and can be applied for obtaining novel vitamin D derivatives.

Opioid-induced endocrinopathy

Debilitating chronic nonmalignant pain is often managed using opioid medications. However, with increased use of this drug class comes concern about adverse effects on patients' endocrine function. In the present review, the authors discuss opioid-induced interference with the hypothalamic-pituitary-gonadal axis, effects on adrenal androgen production, and endocrine deficiency. In addition, the authors describe symptomology for opioid-induced endocrinopathy as well as diagnostic testing options. Treatment modalities for those afflicted with this condition are also described.

Immunoendocrine alterations during human tuberculosis as an integrated view of disease pathology

Tuberculosis (TB) is a chronic infectious disease accompanied by excessive and/or prolonged cytokine production, which might affect the immunoendocrine communication and favor the establishment of an adverse state with important alterations in essential biological functions. Studies in blood from TB patients showed increased levels of interferon gamma (IFN-gamma), interleukin 10 (IL-10), and IL-6, accompanied by a modest increase in the levels of cortisol, prolactin, and thyroid hormones and markedly augmented concentrations of growth hormone. Conversely, testosterone and dehydroepiandrosterone (DHEA) levels were profoundly decreased, resulting in an increased cortisol/DHEA ratio. The finding that culture supernatants from Mycobacterium-tuberculosis-stimulated peripheral blood mononuclear cells (PBMCs) of TB patients inhibit DHEA secretion by a human adrenal cell line indicates that immune cells from these patients can directly affect the synthesis of this hormone. Supporting the existence of bidirectional interactions, in vitro treatment of PBMCs from TB patients with physiological concentrations of cortisol inhibited mycobacterial antigen-driven lymphoproliferation and IFN-gamma production, whereas DHEA suppressed transforming growth factor beta production from cases with progressive disease. Further analysis showed that plasma DHEA levels correlated positively with the in vitroproduction of IFN-gamma by mycobacterial-stimulated PBMCs, and the cortisol/DHEA ratio was inversely correlated with IFN-gamma production. Lastly, it was also shown that the immunoendocrine imbalance in TB patients was associated with weight loss, which in turn correlated with the impairment on their specific in vitro cellular immune responses. These immunoendocrine interactions may play a detrimental role during TB, in terms of the development of protective immune responses, control of tissue damage and metabolic disorders, being implicated in disease aggravation and the 'classic' TB consumption.

Differential regulation of dehydroepiandrosterone and estrogen on bone and uterus in ovariectomized mice

Dehydroepiandrosterone (DHEA) may be useful in the treatment of postmenopausal osteoporosis (PMO). Our present study has found the preferable stimulatory effect of DHEA on bone, in contrast to the proliferative effects of estradiol (E2) on the endometrium and the uterus, which suggests that DHEA has greater potential clinical value than estrogens in prophylaxis and therapeutics for PMO.

INTRODUCTION

A series of findings raise the possibility that DHEA may be useful in the treatment of PMO. Our present study thus aimed at the differential effects of DHEA and E2 on bone and the uterus in ovariectomized mice as well as the involvement of aromatase, ERalpha, ERbeta, and AR in the effects.

METHODS

Ovariectomized and sham BALB/c mice were given daily treatment with either DHEA or E2 for three months, respectively. Bone mineral density was determined by DEXA after the last treatment. Mice were necropsied in 3 months after the treatment to analyze the ultrastructure of their femur osteoblasts (OBs) with a transmission electron microscope (TEM); DHEA, DHEA sulfate (DHEAS) and E2 levels were assayed by EIA; production in vitro of E2 in the uterus or tibia was assayed to evaluate the profile of P450arom activity; ERalpha and ERbeta mRNA levels in the uterus and tibia were determined by real-time PCR. The primary murine OBs were treated with DHEA and E2, respectively for 72 h. Real-time polymerase chain reaction (PCR) and western blot were carried out to evaluate aromatase, ERalpha, ERbeta and AR expression in OBs.

RESULTS

Both DHEA and E2 significantly improved BMD and OB ultrastructure; E2 but not DHEA has significantly increased uterus wet weight, endometrium epithelial and gland thickness. Dehydroepiandrosterone not only increased serum, femoral DHEA, DHEAS and E2 concentration, but also increased uterine DHEA and DHEAS other than E2 concentration in site, while E2 only increased serum, uterine and femoral E2 concentration, but failed to alter the concentrations of DHEA and DHEAS. Moreover, DHEA significantly increased tibia P450arom enzyme activity, while E2 increased uterine and tibia aromatase activity. Furthermore, DHEA increased uterine ERbeta and ERalpha, and ERbeta transcription in the tibia, while E2 increased ERalpha transcription in the uterus and tibia. Dehydroepiandrosterone increased aromatase, ERalpha, ERbeta and AR expression in OBs, and increased significantly, but E2 apparently decreased the ratio of ERbeta/ERalpha.

CONCLUSIONS

Although both DHEA and E2 augment BMD, the proliferative effects of E2 on the endometrium and uterus reflect the different modes of action on bone and the uterus, indicating that the preferable stimulatory effect of DHEA on bone appears to the more potential clinical values than estrogens in prophylaxis and therapeutics for PMO. But applicability of the findings from rodents in humans needs further study.

Dehydroepiandrosterone anti-atherogenesis effect is not via its conversion to estrogen

AIM

This study was conducted to demonstrate the anti-atherosclerotic effect of dehydroepiandrosterone (DHEA) and to investigate its possible mechanisms and whether this effect is related to its conversion to estrogen.

METHODS

Forty male New Zealand White rabbits aged 3 months were divided into 5 groups (n=8 per group) and fed different diets for 10 weeks. Serum lipid levels, the area of atherosclerotic lesions and the mRNA levels of monocyte chemoattractant protein-1 (MCP-1) and vascular cell adhesion molecule-1 (VCAM-1) in aortic lesions were measured. Then cultured vascular smooth muscle cells (VSMCs) stimulated by oxidized low density lipoprotein-cholesterol (ox-LDL) were treated by DHEA. The gene and protein expression levels of MCP-1 and VCAM-1 in VSMCs was detected. The plasmid with or without the gene of cytochrome P450 aromatase (CYP19) was transient transfected into cultured VSMCs respectively. Twenty hours later, the cells were stimulated with ox-LDL and DHEA.

RESULTS

DHEA could obviously decrease the area of atherosclerotic lesions and the expressions of MCP-1 and VCAM-1 in aortic lesions. But all-trans retinoic acid (atRA) which was reported would limit restenosis after balloon angioplasty had no visible synergistic effect with DHEA. DHEA could also reduce ox-LDL-induced MCP-1 and VCAM-1 expression in untransfected or transfected VSMCs.

CONCLUSION

The anti-atherosclerotic effect of DHEA had nothing to do with the catalysis of cytochrome P450 aromatase (CYP19), or was not related to its conversion to estrogen.

The role of porcine cytochrome b5A and cytochrome b5B in the regulation of cytochrome P45017A1 activities

Male pigs are routinely castrated to prevent the accumulation of testicular 16-androstene steroids, in particular 5alpha-androst-16-en-3-one (5alpha-androstenone), which contribute to an off-odour and off-flavour known as boar taint. Cytochrome P450C17 (CYP17A1) catalyses the key regulatory step in the formation of the 16-androstene steroids from pregnenolone by the andien-beta synthase reaction or the synthesis of the glucocorticoid and sex steroids via 17alpha-hydroxylase and C17,20 lyase pathways respectively. We have expressed CYP17A1, along with cytochrome P450 reductase (POR), cytochrome b5 reductase (CYB5R3) and cytochrome b5 (CYB5) in HEK-293FT cells to investigate the importance of the two forms of porcine CYB5, CYB5A and CYB5B, in both the andien-beta synthase as well as the 17alpha-hydroxylase and C17,20 lyase reactions. Increasing the ratio of CYB5A to CYP17A1 caused a decrease in 17alpha-hydroxylase (p<0.013), a transient increase in C17,20 lyase, and an increase in andien-beta synthase activity (p<0.0001). Increasing the ratio of CYB5B to CYP17A1 also decreased 17alpha-hydroxylase, but did not affect the andien-beta synthase activity; however, the C17,20 lyase, was significantly increased. These results demonstrate the differential effects of two forms of CYB5 on the three activities of porcine CYP17A1 and show that CYB5B does not stimulate the andien-beta synthase activity of CYP17A1.

A possible central mechanism in autism spectrum disorders, part 2: immunoexcitotoxicity

In this section, I explore the effects of mercury and inflammation on transsulfuration reactions, which can lead to elevations in androgens, and how this might relate to the male preponderance of autism spectrum disorders (ASD). It is known that mercury interferes with these biochemical reactions and that chronically elevated androgen levels also enhance the neurodevelopmental effects of excitotoxins. Both androgens and glutamate alter neuronal and glial calcium oscillations, which are known to regulate cell migration, maturation, and final brain cytoarchitectural structure. Studies have also shown high levels of DHEA and low levels of DHEA-S in ASD, which can result from both mercury toxicity and chronic inflammation. Chronic microglial activation appears to be a hallmark of ASD. Peripheral immune stimulation, mercury, and elevated levels of androgens can all stimulate microglial activation. Linked to both transsulfuration problems and chronic mercury toxicity are elevations in homocysteine levels in ASD patients. Homocysteine and especially its metabolic products are powerful excitotoxins. Intimately linked to elevations in DHEA, excitotoxicity and mercury toxicity are abnormalities in mitochondrial function. A number of studies have shown that reduced energy production by mitochondria greatly enhances excitotoxicity. Finally, I discuss the effects of chronic inflammation and elevated mercury levels on glutathione and metallothionein.

Baeyer-Villiger oxidation of DHEA, pregnenolone, and androstenedione by Penicillium lilacinum AM111

The Baeyer-Villiger monooxygenase (BVMO) produced by Penicillium lilacinum AM111, in contrast to other enzymes of this group known in the literature, is able to process 3beta-hydroxy-5-ene steroid substrates. Transformation of DHEA and pregnenolone yielded, as a sole or main product, 3beta-hydroxy-17a-oxa-d-homo-androst-5-en-17-one, a new metabolite of these substrates; pregnenolone was transformed also to testololactone. Testololactone was the only product of oxidation of androstenedione by P. lilacinum AM111. Investigations of the time evolution of reaction progress have indicated that the substrates stimulate activity of BVMO(s) of P. lilacinum AM111.

Role of lysosomal acid lipase in the intracellular metabolism of LDL-transported dehydroepiandrosterone-fatty acyl esters

Dehydroepiandrosterone-fatty acyl esters (DHEA-FAE) belong to a unique family of naturally occurring hydrophobic steroid hormone derivatives that are transported in circulating lipoproteins and may act as a source of dehydroepiendrosterone (DHEA) and other biologically active steroid hormones in cells. Here, we studied the metabolic fate of low-density lipoprotein-associated [(3)H]DHEA-FAE ([(3)H]DHEA-FAE-LDL) and the possible role of lysosomal acid lipase (LAL) in the hydrolysis of DHEA-FAE in cultured human cells. When HeLa cells were incubated with [(3)H]DHEA-FAE-LDL, the accumulation of label in the cellular fraction increased with incubation time and could be inhibited by excess unlabeled LDL, suggesting LDL receptor or LDL receptor-related receptor-dependent uptake. During 48 h of chase, decreasing amounts of [(3)H]DHEA-FAE were found in the cellular fraction, while in the medium increasing amounts of unesterified [(3)H]DHEA and its two metabolites, [(3)H]-5alpha-androstanedione (5alpha-adione) and [(3)H]androstenedione (4-adione), appeared. As LDL-cholesteryl ester hydrolysis is dependent on LAL activity, we depleted LAL from HeLa cells using small interfering RNAs and compared the hydrolysis of [(3)H]DHEA-FAE-LDL and [(3)H]cholesteryl-FAE-LDL. The results demonstrated a more modest but significant reducing effect on the hydrolysis of [(3)H]DHEA-FAE compared with [(3)H]cholesteryl-FAE. Moreover, experiments in LAL-deficient human fibroblasts (Wolman disease patient cells) showed that [(3)H]DHEA-FAE hydrolysis was not completely dependent on LAL activity. In summary, LDL-transported [(3)H]DHEA-FAE entered cells via LDL receptor or LDL receptor-related receptor-mediated uptake, followed by intracellular hydrolysis and further metabolism into 5alpha-adione and 4-adione that were excreted from cells. Although LAL contributed to the deesterification of DHEA-FAE, it was not solely responsible for the hydrolysis.

Dehydroepiandrosterone induces growth arrest of hepatoma cells via alteration of mitochondrial gene expression and function

DHEA is known to have anti-proliferative effect. The mechanism is not completely understood. We investigated the mechanism underlying DHEA-induced growth arrest of hepatoma cells. Growth inhibition was associated with increased G6PD activity, and insensitive to reversal by mevalonate. Thus, DHEA does not act via inhibition of G6PD and HMGR. Instead, growth stagnation was accompanied by reduced expression of nucleus-encoded mitochondrial genes; morphological and functional alterations of mitochondria; and depletion of intracellular ATP. Conversely, pyruvate supplementation alleviated DHEA-induced growth inhibition. It is likely that DHEA suppresses cell growth by altering mitochondrial gene expression, morphology and functions.

Neurosteroids as modulators of neurogenesis and neuronal survival

Neurons and glia in the central nervous system express the necessary enzymes for the synthesis of neurosteroids that are produced in concentrations high enough to exert paracrine effects. Synthesis of brain neurosteroids declines with age, during stressful conditions (including major depression, chronic psychological stress), and in chronic inflammatory and neurodegenerative diseases. Recent reports associate the decrease of brain neurosteroids to neuronal dysfunction and degeneration. This review summarizes the recent findings on how the most studied neurosteroids (dehydroepiandrosterone, pregnenolone and their sulphate esters, progesterone and allopregnanolone) affect neuronal survival, neurite outgrowth and neurogenesis; furthermore, this review discusses potential applications of these neurosteroids in the therapeutic management of neurodegenerative conditions, including that of age-related brain atrophy.

Novel mechanisms for neuroendocrine regulation of aggression

In 1849, Berthold demonstrated that testicular secretions are necessary for aggressive behavior in roosters. Since then, research on the neuroendocrinology of aggression has been dominated by the paradigm that the brain receives gonadal hormones, primarily testosterone, which modulate relevant neural circuits. While this paradigm has been extremely useful, recent studies reveal important alternatives. For example, most vertebrate species are seasonal breeders, and many species show aggression outside of the breeding season, when gonads are regressed and circulating testosterone levels are typically low. Studies in birds and mammals suggest that an adrenal androgen precursor-dehydroepiandrosterone (DHEA)-may be important for the expression of aggression when gonadal testosterone synthesis is low. Circulating DHEA can be metabolized into active sex steroids within the brain. Another possibility is that the brain can autonomously synthesize sex steroids de novo from cholesterol, thereby uncoupling brain steroid levels from circulating steroid levels. These alternative neuroendocrine mechanisms to provide sex steroids to specific neural circuits may have evolved to avoid the "costs" of high circulating testosterone during particular seasons. Physiological indicators of season (e.g., melatonin) may allow animals to switch from one neuroendocrine mechanism to another across the year. Such mechanisms may be important for the control of aggression in many vertebrate species, including humans.

Intravenous lipid and heparin infusion-induced elevation in free fatty acids and triglycerides modifies circulating androgen levels in women: a randomized, controlled trial

BACKGROUND

The polycystic ovarian syndrome (PCOS) is characterized by hyperandrogenism and associated with obesity and impaired glucose metabolism. Despite the high prevalence of PCOS and the considerable clinical impact, the precise interplay between metabolism and hyperandrogenemia is not entirely clear.

OBJECTIVE

The objective of the study was to analyze the effects of iv lipid and heparin infusion on circulating androgen levels in healthy women.

DESIGN

This was a randomized, controlled, crossover trial.

SETTING

The study was conducted at an endocrinology center.

PATIENTS

Patients included 12 healthy young women during the early follicular phase of two subsequent cycles.

INTERVENTION

After an overnight fast, a 20% lipid/heparin or a saline/heparin infusion was administered in random order for 330 min.

MAIN OUTCOME MEASURES

A detailed characterization of androgen metabolism was performed.

RESULTS

Elevations in free fatty acids and triglycerides, induced by lipid/heparin infusion, elevates the levels of androstenedione, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEAS), testosterone, 5alpha-dihydrotestosterone, estrone, and 17beta-estradiol. Urinary excretion of DHEA, DHEAS, 5-androstene-3beta,17beta-diol, and the sum of urinary excreted DHEA and its 16-hydroxylated downstream metabolites, 16alpha-hydroxy-DHEA and 5-androstene-3beta,16alpha,17beta-triol, were reduced.

CONCLUSION

The mechanism of iv lipid and heparin infusion-induced elevation of circulating androgens described here might contribute to the development of hyperandrogenism in women with PCOS and suggests that lowering of hyperlipidemia might be a potential therapeutic target in patients with PCOS to treat hyperandrogenemia.