Beta-hydroxysteroid Dehydrogenase Activity Research Articles

Abstract B034: Characterization of a dual steroid 3β-,17β-oxidoreductase in the gut bacterium Eggerthella lenta

Abstract As of 2023 there are over 200,000 new cases and over 30,000 deaths caused by prostate cancer with African-American (AA) men having a higher incidence then other ethnicities according to the American Cancer Society. Although numerous therapeutic methods are used to treat prostate cancer such as hormone therapy, radiation therapy, chemotherapy, and chemical castration, prostate cancer often becomes metastatic resulting in death with the five year survival rate for AA men presenting with castration resistant prostate cancer (CRPC) being ~ 32%. Androgen production is known to be the main driver of CRPC progression. Researchers are baffled as to why this progression is taking place after patients have received a combination of these therapeutic methods to stop androgen production and metabolism. Eggerthella lenta has a long history as an important bile acid and steroid metabolizing gut microbial species. We and others have previously published on the extensive oxidation and epimerization of bile acid hydoxyl groups. Previous work demonstrated that E. lenta may be involved in the conversion of 17-keto steroids to testosterone. By cloning, expressing, and purifying genes predicted to encode pyridine nucleotide-dependent oxidoreductases from E. lenta DSM 2243, we identified a recombinant enzyme with dual 3beta, 17beta-hydroxysteroid dehydrogenase activity. We performed kinetic analysis on both 5alpha-reduced bile acids ("allo"-bile acids) and 5alpha-reduced steroids. There is a paucity of work at present on gut bacteria that metabolize the 17beta-hydroxy group on steroids, so this observation demonstrates that a unique enzyme in the gut microbiome can alter host steroids. These findings are consistent with the possibility that gut or urinary tract bacteria may contribute to CRPC. Citation Format: Briawna J. Binion, Rex Gaskins, Jason Ridlon. Characterization of a dual steroid 3β-,17β-oxidoreductase in the gut bacterium Eggerthella lenta [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr B034.

In vivo exposure to bisphenol F induces oxidative testicular toxicity: role of Erβ and p53/Bcl-2 signaling pathway.

Bisphenol F (BPF), an alternative to bisphenol A has been implicated as a gonadotoxic substance. BPF has been shown to induce hormonal imbalance and testicular oxidative damage. However, the mechanism associated with BPF-induced testicular toxicity has not been fully explored. This study was designed to explore the role of tumor protein (p53)/ B-cell lymphoma 2 (BCl-2) signaling and oestrogen receptor beta (Erβ) in BPF-induced testicular toxicity. Male Wistar rats were randomized into control (Cntrl), BPF-treated (10, 30, and 50 mg/kg for low dose (BPF-L), medium dose (BPF-M), and high dose (BPF-H) respectively), and BPF-treated recovery (Cntrl-R, BPF-L-R, BPF-M-R, and BPF-H-R). The administration was via gavage and lasted for 28 days and the animals in the recovery groups were allowed 28-days exposure free period for recovery from BPF exposure. BPF resulted in the distortion of the testicular histoarchitecture, which was accompanied by a significant rise in testicular gamma-lutamyl transferase and lactate dehydrogenase activities but a decline in sorbitol dehydrogenase activities. Also, BPF caused a significant reduction in plasma gonadotropin-releasing hormone, luteinising hormone, follicle-stimulating hormone, and testosterone, which was associated with the downregulation of testicular 3beta-hydroxysteroid dehydrogenase and 17beta-hydroxysteroid dehydrogenase activities. Furthermore, BPF induced testicular inflammation, redox imbalance, and apoptosis, accompanied by distortion in p53/BCl-2 signaling and overexpression of Erβ. Again, the observed toxic effects of BPF were dose-dependent and not completely reversed by BPF cessation. Bisphenol F induced gonadotoxicity by distorting p53/BCl2 signaling and the expression of Erβ. These observed alterations were not completely reversed after the cessation of BPF exposure.

EFFICACY OF Nigella sativa OIL TO RELIEVE EFFECTS OF THE LEAD MONOXIDE TOXICITY ON TESTICULAR EFFICIENCY AND SEXUAL BEHAVIOUR DISORDERS IN ALBINO RATS

The prevalence of testicular toxicity induced via contamination with heavy metals is increasing worldwide, and a close connection between testicular toxicity and lead has recently been identified. The present study demonstrated the possible therapeutic and protection properties of Nigella sativa oil (NSO) against dangerous testicular toxicity and sexual behaviour disorders in rat models induced by lead monoxide (PbO) food poisoning. A total of 24 male rats were used and divided into four groups, consisting of Group 1: Control (1 mL of distilled water); Group 2: PbO (80 mg/kg); Group 3: NSO (0.5 mL/rat); and Group 4: (NSO+PbO) 0.5 mL/rat of NSO, followed by PbO (80 mg/kg/day) respectively for 60 days. The testosterone, follicle-stimulating hormone (FSH), luteinizing hormone (LH), 17 beta-hydroxysteroid dehydrogenase activity (17β-HSD), sperm parameters, and sexual behaviour (copulation behaviour test) were measured. The results showed that sex hormone levels were significantly decreased (p<0.05) in rats exposed to PbO, while the levels of these hormones were significantly higher in rats exposed to NSO and NSO+PbO. The sperm parameters (numbers, concentrations, motilities, and abnormality) were lower in rats exposed to PbO compared to those in the control, NSO, and NSO+PbO groups that showed significant increases. Sperm abnormality and 17β-HSD activity showed a significant increase at p<0.05 in the group exposed to the PbO compared to those of the control, NSO, and NSO+PbO groups. The results also significantly suppressed sexual behaviour in rats exposed to PbO compared to those in the control, NSO, and NSO+PbO groups, rats were administered NSO+PbO showed improvement in sexual behaviour parameters compared to PbO groups. PbO toxicity was obvious in the reproductive tract through severe histopathological changes. The impact of lead on tissues was partially mitigated by NSO. The study showed protective effects of N. sativa oil against changes in sex hormones, sperm characteristics, and sexual behaviour in male rats exposed to lead monoxide-induced testicular toxicity.

Influence of labor on direct and indirect determinants of placental 11beta-hydroxysteroid dehydrogenase activity

PurposeLabor is a complex process involving multiple para-, auto- and endocrine cascades. The interaction of cortisol, corticotropin-releasing hormone (CRH) and progesterone is essential. The action of cortisol on the human feto-placental unit is regulated by 11beta-hydroxysteroid dehydrogenase type 2 (11β-HSD2/HSD11B2) that converts cortisol into inactive cortisone. The majority of studies on the assessment of placental 11β-HSD2 function determined indirect activity parameters. It remains elusive if indirect measurements correlate with enzymatic function and if these parameters are affected by potential confounders (e.g., mode of delivery). Thus, we compared determinants of indirect 11β-HSD2 tissue activity with its direct enzymatic turnover rate in placental samples from spontaneous births and cesarean (C)-sections.MethodsUsing LC–MS/MS, we determined CRH, cortisol, cortisone, progesterone and 17-hydroxy(OH)-progesterone in human term placentas (spontaneous birth vs. C-section, n = 5 each) and measured the enzymatic glucocorticoid conversion rates in placental microsomes. Expression of HSD11B1, 2 and CRH was determined via qRT-PCR in the same samples.ResultsCortisol–cortisone ratio correlated with direct microsomal enzymatic turnover. While this observation seemed independent of sampling site, a strong influence of mode of delivery on tissue steroids was observed. The mRNA expression of HSD11B2 correlated with indirect and direct cortisol turnover rates in C-section placentas only. In contrast to C-sections, CRH, cortisol and cortisone levels were significantly increased in placental samples following spontaneous birth.ConclusionLabor involves a series of complex hormonal processes including activation of placental CRH and glucocorticoid metabolism. This has to be taken into account when selecting human cohorts for comparative analysis of placental steroids.

Global 11 Beta-Hydroxysteroid Dehydrogenase Activity Assessed by the Circulating Cortisol to Cortisone Ratio is Associated with Features of Metabolic Syndrome.

Background: 11 Beta-hydroxysteroid dehydrogenases (11HSDs) are enzymes involved in the interconversion of cortisol and cortisone. There are two isoenzymes of 11HSD, 11HSD1 and 11HSD2. A causative role of 11HSD, particularly 11HSD1, in metabolic syndrome is well established in experimental animals. However, its role in human metabolic syndrome is less clear. We examined the influence of global 11HSD activity on metabolic syndrome in the general population, using the circulating cortisol:cortisone ratio as an index of global 11HSD activity. Methods: A subsample of 269 sera randomly selected from the Thai National Health Examination Survey IV samples was analyzed for serum cortisol and cortisone levels by liquid chromatography-tandem mass spectrometry. Results: There was no association between serum cortisol and age. However, circulating cortisone was negatively correlated with age (r = -0.12, P < 0.001), and the serum cortisol:cortisone ratio was positively associated with age (r = 0.03, P < 0.001). No association was found between serum cortisol:cortisone ratio and body mass index (BMI) or serum lipids. Multivariate analyses showed that the serum cortisol:cortisone ratio was associated with high blood pressure (P < 0.05) independent of age, BMI, and sex. In subjects without hypertension, the serum cortisol to cortisone ratio was associated with mean systolic blood pressure after controlling for age, BMI, and sex. The cortisol:cortisone ratio was not significantly different between subjects with and without diabetes. After excluding the 16 subjects with diabetes, it was found that the serum cortisol:cortisone ratio was positively associated with fasting plasma glucose independent of age, BMI, and sex (P < 0.01). Conclusions: The global index of 11HSD activity, assessed by the circulating cortisol:cortisone ratio, was related to high blood pressure and fasting plasma glucose and may serve as a proxy to global 11HSD activity.

Higher androgen bioactivity is associated with excessive erythrocytosis and chronic mountain sickness in Andean Highlanders: a review.

Populations living at high altitudes (HA), particularly in the Peruvian Central Andes, are characterised by presenting subjects with erythrocytosis and others with excessive erythrocytosis (EE)(Hb>21 g dl(-1) ). EE is associated with chronic mountain sickness (CMS), or lack of adaptation to HA. Testosterone is an erythropoietic hormone and it may play a role on EE at HA. The objective of the present review was to summarise findings on role of serum T levels on adaptation at HA and genes acting on this process. Men at HA without EE have higher androstenedione levels and low ratio androstenedione/testosterone than men with EE, suggesting low activity of 17beta-hydroxysteroid dehydrogenase (17beta-HSD), and this could be a mechanism of adaptation to HA. Higher conversion of dehydroepiandrosterone to testosterone in men with EE suggests nigher 17beta-HSD activity. Men with CMS at Peruvian Central Andes have two genes SENP1, and ANP32D with higher transcriptional response to hypoxia relative to those without. SUMO-specific protease 1 (SENP1) is an erythropoiesis regulator, which is essential for the stability and activity of hypoxia-inducible factor 1 (HIF-1α) under hypoxia. SENP1 reverses the hormone-augmented SUMOylation of androgen receptor (AR) increasing the transcription activity of AR.In conclusion, increased androgen activity is related with CMS.

Oral supplementation of standardized extract of Withania somnifera protects against diabetes-induced testicular oxidative impairments in prepubertal rats

Male reproductive dysfunctions and infertility are the common consequences of overt diabetes. Available evidence support oxidative stress to be the underlying mechanism for the manifestation of testicular complications during diabetes. In the present study, we assessed the attenuating effects of Withania somnifera root extract (WS) on diabetes-induced testicular oxidative disturbances in prepubertal rats. Four-week-old prepubertal rats were assigned into nondiabetic control, streptozotocin (STZ)-treated and STZ+WS supplemented (500 mg/kg b.w./d, oral, 15 days) groups. Experimental diabetes was induced by a single intraperitoneal injection of STZ (90 mg/kg b.w). Terminally, all animals were killed, and markers of oxidative stress were determined in the testis cytosol and mitochondrial fraction. Severe hyperglycemia and regression in testis size were apparent in diabetic rats. A decline in antioxidant defenses with subsequent elevation in the generation of reactive oxygen species and lipid peroxidation was discernible in testis cytosol and mitochondria of diabetic prepubertal rats, which was significantly reversed by WS. However, there was partial restoration of glucose-6-phosphate dehydrogenase, lactate dehydrogenase, and 3-beta hydroxysteroid dehydrogenase activities in testis of diabetic prepubertal rats administered with WS. Taken together, data accrued suggest the potential of WS to improve diabetes-induced testicular dysfunctions in prepubertal rats.

Evidence for glucocorticoid-mediated hypertension after uninephrectomy

Recently, evidence was presented that uninephrectomy induces salt-sensitive hypertension in rats. The increase in blood pressure was abrogated by a mineralocorticoid receptor antagonist but not by an aldosterone synthase inhibitor. Here, we hypothesize that mineralocorticoid receptor activation occurred by an 11beta-hydroxy-glucocorticosteroid, as a consequence of dysregulated 11beta-hydroxysteroid dehydrogenase enzymes. Therefore, 3-week-old Sprague-Dawley rats were either uninephrectomized or sham operated and given a normal (0.4%) or high (8%)-salt diet. At week 8, a telemetric device was implanted, and during week 13 blood pressure continuously measured and urine was collected. The animals were sacrificed thereafter and liver and kidney were harvested. Steroid metabolites were analyzed by GC-MS and mRNA assessed by PCR. Uninephrectomy caused a distinct salt-sensitive hypertension. The increase in blood pressure correlated significantly with a decline in the apparent activity of 11beta-hydroxysteroid dehydrogenase 2 and an increase of 11beta-hydroxysteroid dehydrogenase 1, when urinary corticosterone metabolites were considered. These results were mirrored by the corresponding metabolite ratios assessed in renal and liver tissue. Changes in enzyme activities were in part explained by changes in the mRNA content. In conclusion, mineralocorticoid receptor-dependent salt sensitivity after UNX in rats appears to be mediated by glucocorticoids.

Serum testosterone levels and excessive erythrocytosis during the process of adaptation to high altitudes

Populations living at high altitudes (HAs), particularly in the Peruvian Andes, are characterized by a mixture of subjects with erythrocytosis (16 g dl(-1)<haemoglobin (Hb)≤21 g dl(-1)) and others with excessive erythrocytosis (EE) (Hb>21 g dl(-1)). Elevated haemoglobin values (EE) are associated with chronic mountain sickness, a condition reflecting the lack of adaptation to HA. According to current data, native men from regions of HA are not adequately adapted to live at such altitudes if they have elevated serum testosterone levels. This seems to be due to an increased conversion of dehydroepiandrosterone sulphate (DHEAS) to testosterone. Men with erythrocytosis at HAs show higher serum androstenedione levels and a lower testosterone/androstenedione ratio than men with EE, suggesting reduced 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activity. Lower 17beta-HSD activity via Δ4-steroid production in men with erythrocytosis at HA may protect against elevated serum testosterone levels, thus preventing EE. The higher conversion of DHEAS to testosterone in subjects with EE indicates increased 17beta-HSD activity via the Δ5-pathway. Currently, there are various situations in which people live (human biodiversity) with low or high haemoglobin levels at HA. Antiquity could be an important adaptation component for life at HA, and testosterone seems to participate in this process.

Editorial: The Future of Development

We have investigated the developmental potential of mouse blastocysts cultured under a variety of conditions. A number of parameters were used as criteria for development and differentiation, namely hatching of blastocysts from the zona pellucida and their adhesion to the substratum, outgrowth and polyploidization of trophoblast cells, increase in cell number, protein content, beta-glucuronidase activity, appearance of lactate dehydrogenase A subunits, plasminogen activator production, and delta 5,3 beta hydroxysteroid dehydrogenase activity. Under optimal culture conditions, embryos grew relatively rapidly and expressed all the differentiative markers for which they were tested. Under less supportive conditions, the production of the markers was usually reduced quantitatively; the expression of some markers could also be considerably delayed or even totally prevented. In fact, embryos cultured in the least nutritive medium (one designed to support development only through pre-implantation stages) appeared to be in a state of metabolic quiescence closely resembling that of blastocysts in ovariectomy-induced delay. Overall, the results of our investigations lead us to propose that the expression of each of the aforementioned markers is probably under independent control and subject to intrinsic programming. Finally, the observation that some markers are produced by embryos in suboptimal media whereas others are not, suggests that the minimum metabolic level necessary for expression varies from one marker to another.

Evidence for a Luteotropic Role of Peroxisome Proliferator-Activated Receptor Gamma: Expression and In Vitro Effects on Enzymatic and Hormonal Activities in Corpora Lutea of Pseudopregnant Rabbits1

The expression of peroxisome proliferator-activated receptor gamma (PPARgamma) and its role in corpora lutea (CL) function were studied in pseudopregnant rabbits. Corpora lutea were collected at an early stage (Day 4), midstage (Day 9), and late stage (Day 13) of pseudopregnancy. Immunohistochemistry found evidence for the presence of PPARgamma in the perinuclear cytoplasm and nucleus of all the luteal cells; immunoreactivity decreased from the early to the late stage, with immunonegativity of the nuclei of late stage CL. PPARgamma mRNA transcript was expressed in all the luteal stages with the lowest level in the late stage. In CL cultured in vitro, the PPARgamma agonist (15-deoxy delta12,14 prostaglandin J2 [15d-PGJ2], 200 nM) increased and the antagonist (T0070907, 50 nM) decreased progesterone secretion at early and midluteal stages, whereas 15d-PGJ2 reduced and T0070907 increased PGF2alpha at the same stages. Prostaglandin-endoperoxide synthase 2 (PTGS2) activity was reduced by 15d-PGJ2 and increased by T0070907 in CL of early and midluteal stages. Conversely, 15d-PGJ2 increased and T0070907 reduced 3beta-hydroxysteroid dehydrogenase (3beta-HSD) activity in early and midluteal stage CL. PGE2 in vitro secretion as well as PTGS1 and 20alpha-HSD enzymatic activities were not affected by 15d-PGJ2 and T0070907 in any CL types. These results indicate that PPARgamma plays a luteotropic role in pseudopregnant rabbits, through PTGS2 down-regulation and 3beta-HSD up-regulation, with a consequent PGF2alpha decrease and progesterone increase.

Adrenocortical and renin-angiotensin systems in dynamics of experimental diabetes

Components of the adrenocortical system (adrenal and blood corticosteroid hormones and hepatic and renal 11beta-hydroxysteroid dehydrogenase activity) and also activity of the most important enzyme of the renin-angiotensin system, tissue and blood angiotensin converting enzyme (ACE) have been investigated in dynamics of alloxan diabetes. The study has shown that the initial period of diabetes is characterized by activation of synthesis and secretion of adrenocortical hormones into blood. High blood glucose and glucocorticoid honnones increase activity of the renin-angiotensin system in lungs and decrease ACE secretion into blood. This is accompanied by a decrease of activity of the renin-angiotensin system in kidneys. Subsequent progression of diabetes resulted in impairments of physiologically determined correlations between the components of these systems. Development of experimental diabetes for 30 days was accompanied by sign of a decrease of the adrenal glucocorticoid function regardless of stable impairments of carbohydrate metabolism. Under these conditions increased adrenal and hepatic 11beta-hydroxysteroid dehydrogenase activity may be responsible for maintenance of elevated levels of the main glucocorticoid in blood and tissues. Factor analysis revealed impairments in intersystem relationships between the adrenocortical and renin-angiotensin systems in experimental diabetes thus suggesting disintegration of regulatory systems.

Targeting activated mineralocorticoid receptor: Occam's razor revisited

Activation of mineralocorticoid receptors (MRs) classically has been associated with electrolyte transport, but we now know that MR activation can also lead to tissue inflammation and fibrosis. Aldosterone consistently activates MR, but under selected circumstances, endogenous glucocorticoids such as cortisol and corticosterone can also trigger MR. Tissue-specific safeguards such as the enzyme 11β-hydroxysteroid dehydrogenase limit glucocorticoid-induced MR activation, while the presence of reactive oxygen species may enhance the ability for glucocorticoid-induced MR activation even in the absence of aldosterone.

The effect of dexamethasone on the activity of 11beta-hydroxysteroid dehydrogenase in the foetal rabbit lung during the final stage of gestation.

The effect of dexamethasone on the activity of 11beta-hydroxysteroid dehydrogenase in the foetal rabbit lung during the final stage of gestation.

Activation of 11 beta-hydroxysteroid dehydrogenase by dehydroepiandrosterone sulphate as an anti-hypertensive agent in spontaneously hypertensive rats.

The anti-hypertensive properties of dehydroepiandrosterone sulphate (DHEAS) have been investigated by studying its effects on blood pressure, on serum concentrations of corticosterone and dehydrocorticosterone, and on 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) activity in spontaneously hypertensive rats (SHR). SHR were given intraperitoneal injections of DHEAS (10 mg day-1 for 70 days) from six to 16 weeks of age. The blood pressure-time curve was significantly (P < 0.05) suppressed immediately after administration of DHEAS. There was no difference between the heart rates of control and DHEAS groups. Serum concentrations of corticosterone and dehydrocorticosterone in the DHEAS group were significantly (P < 0.05) lower than those of the control group. The dehydrocorticosterone/corticosterone concentration ratio was, however, significantly (P < 0.05) higher in the DHEAS group, suggesting that treatment with DHEAS enhanced the overall interconversion of corticosterone to dehydrocorticosterone. The activity of 11 beta-HSD in specific organs of the DHEAS group was affected, characteristic changes being increases in the kidney (14-58%), decreases in the liver (11-27%) and no change in the testis. Direct addition of DHEAS to 11 beta-HSD preparations from the kidneys of control SHR had the same effect as that observed in the in-vivo experiments. The fall in serum corticosterone in the DHEAS group is considered to be related, at least partly, to increased activity of kidney 11 beta-HSD. The inverse correlation of kidney 11 beta-HSD activity with serum corticosterone and blood pressure (-r = 0.628, P < 0.01, and -r = 0.478, P < 0.05, respectively) suggest that DHEAS delayed the development of hypertension in SHR by selective promotion of kidney 11 beta-HSD activity which in turn resulted in lower serum concentrations of corticosterone and its minimal aldosterone-like activity.

Dynamics of endogenous glucocorticoid secretion and its metabolism in Kawasaki disease

Objective Kawasaki disease (KD) is a severe inflammatory disease that occurs in childhood. Recently, the initial corticosteroid therapy for KD has been reconsidered because its efficacy is controversial. The aim of this study was to evaluate the dynamic change in endogenous glucocorticoid levels and their relation with 11beta-hydroxysteroid dehydrogenase (11β-HSD) activity in the acute phase of KD. Study design Sixteen KD patients were investigated. Cortisol and cortisone levels, the cortisol/cortisone ratio and C-reactive protein (CRP) levels were measured on admission, before the first intravenous immunoglobulin (IVIG) therapy and convalescence. Results The 16 patients were divided into two groups. Group A included patients who received the first IVIG on admission and blood samples were collected before the first IVIG and convalescence. Group B included patients whose blood samples were collected at three different time points (on admission, before the first IVIG, and convalescence). CRP and cortisol levels and the cortisol/cortisol ratio were markedly higher before the first IVIG than those of convalescence in all patients except in one patient. In Group B patients, both serum cortisol levels and the cortisol/cortisone ratio on admission were significantly increased compared with those before the first IVIG (cortisol: p < 0.005, cortisol/cortisone: p < 0.001). Conclusions Decreases in cortisol levels and the cortisol/cortisone ratio before the first IVIG may be explained by a reduction in adrenal secretion and/or local glucocorticoid action through 11β-HSD activity. These findings suggest that exogenous glucocorticoid treatment in combination with the first IVIG at the acute stage may play a synergetic role in KD.

LEVELS OF THE CORTISOL, CORTISONE AND THEIR METABOLITES AS A MARKERS OF APPARENT MINERALOCORTICOID EXCESS (AME) – CASE PRESENTATION: PP.18.200

Among the causes of secondary hypertension are a group of disorders with a Mendelian inheritance pattern. Apparent mineralocorticoid excess (AME) is an autosomal recessive disease caused by deficiency of the enzyme 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2). 11beta-HSD2 is responsible for conversion of cortisol (F) to inactive cortisone (E). In AME deficiency of 11beta-HSD2 allows the unmetabolized cortisol to bind to the mineralocorticoid receptor inducing sodium retention, hypokalemia, suppression of plasma renin activity (PRA) and hypertension. F and E are metabolized in the liver - the reaction is catalyzed by alfa-reductase obtaining allo-tetrahydrocortisol (allo-THF) and allo-tetrahydrocortisone (allo-THE). For beta-reductase followed the products are: tetrahydrocortisol (THF) and tetrahydrocortisone (THE). The balance between 11beta-HSD1 and 11beta-HSD2 activity can be demonstrated by measuring the ratio of reduced metabolites of F and E in urine as well as by determining of urinary free cortisol (UFF) and cortisone (UFE). Plasma F/E ratio is another valuable parameter in estimation of the coordinated activity of two isoforms of 11beta-hydroxysteroid dehydrogenase. Case presentation: 67 years old white men with the five years history of hypertension was admitted to the hospital with the suspicion of primary aldosteronism. Lab tests: unprovoked low plasma potassium (3.3 mmol/l), decreased serum aldosterone level (11.64 pg/ml) and normal PRA (1.30 ng/ml/h). Left ventricular hypertrophy was found in echocardiography, but in ultrasound suprarenal glands were normal. F, E and their metabolites, after extraction from human plasma and urine and after pre-column derivatization, were determined using high performance liquid chromatography methods. The following results were obtain: serum F/E - 13.12; UFF/UFE in urine – 1.48; (THF+allo-THF)/(THE+allo-THE) in urine - 1,70. Patient's hormone levels were significantly different in compare with levels obtain in control group (healthy volunteers, n = 14) – 3.97 ± 1.43; 0.42 ± 0.16 and 0.79 ± 0.19 respectively. The presented data show the screening tool in the assessment of abnormalities of 11beta-hydroxysteroid dehydrogenase activity, but the final diagnosis should be confirm by molecular analysis of the gene.

Inhibitory effects of melatonin on sulfatase and 17β-hydroxysteroid dehydrogenase activity and expression in glioma cells

Melatonin interacts with estradiol at the estrogen receptor level in different kinds of neoplasias and also regulates the expression and the activity of some enzymes involved in the biosynthesis of estrogens in peripheral tissues. Glioma cells express estrogen receptors and have the ability to synthesize estrogens locally. Since melatonin inhibits the growth of C6 cells, and this indoleamine has been demonstrated to be capable of decreasing aromatase expression and activity in these cells, the aim of the present study was to analyze whether the regulation of the sulfatase, the enzyme that catalyzes the rate-limiting step in the conversion of estrogen sulfates to estrogens, and 17beta-hydroxysteroid dehydrogenase, the enzyme which converts the relatively inactive estrone to the most potent 17beta-estradiol, could be involved in the inhibition of glioma cell growth by melatonin. We found that melatonin decreases the growth of C6 glioma cells and reduces the sulfatase and 17beta-hydroxysteroid dehydrogenase activity. Finally, we demonstrated that melatonin downregulates sulfatase and 17beta-hydroxysteroid dehydrogenase mRNA steady state levels in these glioma cells. By analogy to the implications of these enzymes in other forms of estrogen-sensitive tumors, it is conceivable that their modulation by melatonin may play a role in the growth of glioblastomas.

Molecular Cloning and Functional Characterization of a Zebrafish Nuclear Progesterone Receptor1

Progestagenic sex steroid hormones play critical roles in reproduction across vertebrates, including teleost fish. To further our understanding of how progesterone modulates testis functions in fish, we set out to clone a progesterone receptor (pgr) cDNA exhibiting nuclear hormone receptor features from zebrafish testis. The open reading frame of pgr consists of 1854 bp, coding for a 617-amino acid-long protein showing the highest similarity with other piscine Pgr proteins. Functional characterization of the receptor expressed in mammalian cells revealed that zebrafish Pgr exhibited progesterone-specific, dose-dependent induction of reporter gene expression, with 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (DHP), a typical piscine progesterone, showing the highest potency. Expression of pgr mRNA: 1) appeared in embryos at 8 h after fertilization; 2) was significantly higher in developing ovary than in early transforming testis at 4 wk of age but vice versa in young adults at 12 wk of age, and thus resembling the expression pattern of the germ cell marker piwil1; and, 3) was restricted to Leydig and Sertoli cells in adult testis. Zebrafish testicular explants released DHP concentration dependently in response to high concentrations of recombinant zebrafish gonadotropins. In addition, DHP stimulated 11-ketotestosterone release from zebrafish testicular explants, but only in the presence of its immediate precursor, 11 beta-hydroxytestosterone. This stimulatory activity was blocked by a Pgr antagonist (RU486), suggesting that 11 beta-hydroxysteroid dehydrogenase activity was stimulated by DHP via Pgr. Our data suggest that DHP contributes to the regulation of Leydig cell steroidogenesis, and potentially--via Sertoli cells--also to germ cell differentiation in zebrafish testis.

Hypocortisolism in the South African Angora goat: The role of 3βHSD

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.