Background: Excessive androgenesis in the skin promotes sebaceous hyperproduction which is the onset of acne vulgaris pathogenesis. Free fatty acids and lipid accumulation in the glandular infundibulum culminates in microbiota imbalance, triggering inflammatory response and follicular hyperkeratinization.

Aims: The purpose of this work was to present an alternative cosmetic treatment for acne skin care, focusing on the prevention of sebaceous gland dysregulation.

<strong class="sub-title">Methods:</strong> Insulin-stimulated human sebocytes were treated with noncytotoxic concentrations of a DTRW cosmetic formulation. After 6 days of incubation, cell lysates were collected for testosterone, <em>5α</em>-reductase, and dyhidrotestosterone (<em>DHT</em>) quantitation. In parallel, cells were stained with Oil Red O to measure sebum production.

<strong class="sub-title">Results:</strong> Human sebocytes were incubated with insulin to mimic a seborrheic microenvironment with overproduction of intracellular lipids and fatty acids. Concomitant incubation of cell cultures with DRTW was able to promote a 52.97% reduction in intracellular lipid content. The anti-androgenic properties of DRTW had been proved by the reductions of testosterone (↓59.90%), <em>5α</em> reductase (↓59.34%), and <em>DHT</em> (↓55.98%) levels in sebocyte cultures also stimulated with insulin.

Conclusion: The results indicate a promising action of DRTW cosmetic formulation in preventing the development of acne lesions by mechanisms involving the modulation of cutaneous androgenesis and consequently the control of sebum overproduction, considered one of the leading causes of acne.

<strong class="sub-title">Keywords:</strong> <em>5α</em> reductase; acne vulgaris; androgen; dihydrotestosterone; sebaceous gland; sebum.

This study assessed the effects of chronic dehydroepiandrosterone (DHEA) administration and exercise training on testicular sex steroid hormone levels and reproductive function in high-sucrose induced obese rats. After 14 weeks of a high-sucrose diet, Wistar male rats were assigned randomly to the control, exercise training (running at 25 m/min for 1 h, 5 days/week), DHEA administration, and combined exercise training and DHEA administration groups (n = 7 each group). Six weeks of DHEA administration and/or exercise training significantly increased plasma concentrations of DHEA and <em>5α</em>-dihydrotestosterone (<em>DHT</em>) and epididymis DHEA concentrations; however, the expression of steroidogenic enzymes, such as 3β-hydroxysteroid dehydrogenase (HSD), 17β-HSD, and <em>5α</em>-reductase, did not change following any interventions. Procathepsin L expression, which involved sperm maturation, was significantly lower in the DHEA and combination groups, and glutathione peroxidase 4 (GPx4) expression, which plays a role in protecting sperms from oxidative stress, was significantly increased in the DHEA administration group. Additionally, exercise training and/or DHEA administration-induced increase in procathepsin L expressions were significantly correlated with the epididymis DHEA concentrations. These findings suggest that exercise training and/or DHEA administration-induced increase in epididymis DHEA concentration may improve impairment of reproductive function in high-sucrose obese rats. Additionally, exercise training and/or DHEA administration-induced increase in DHEA concentration may have a role in testicular-specific action, which included protective role from exercise-induced oxidant damage as well as contributed to the enhancement of sperm modification and maturation in obese rats.

Gastropod mollusks have been proposed as alternative models for male reproductive toxicity testing, due to similarities in their reproductive anatomy compared to mammals, together with evidence that endocrine disrupting chemicals can cause effects in some mollusks analogous to those seen in mammals. To test this hypothesis, we used the freshwater pulmonate snail, Biomphalaria glabrata, for which various genetic tools and a draft genome have recently become available, to investigate the effects of two steroid androgens on the development of mollusk secondary sexual organs. Here we present the results of exposures to two potent androgens, the vertebrate steroid; <em>5α</em>-dihydrotestosterone (<em>DHT</em>) and the pharmaceutical anabolic steroid; 17α-methyltestosterone (MT), under continuous flow-through conditions throughout embryonic development and up to sexual maturity. Secondary sexual gland morphology, histopathology and differential gene expression analysis were used to determine whether steroid androgens stimulated or inhibited organ development. No significant differences between tissues from control and exposed snails were identified, suggesting that these androgens elicited no biologically detectable response normally associated with exposure to androgens in vertebrate model systems. Identifying no effect of androgens in this mollusk is significant, not only in the context of the suitability of mollusks as alternative model organisms for testing vertebrate androgen receptor agonists but also, if applicable to other similar mollusks, in terms of the likely impacts of androgens and anti-androgenic pollutants present in the aquatic environment.

Sexually immature male mice exhibit parenting behavior toward unfamiliar pups; however, the percentage of males that engage in infanticidal behavior gradually increases with age. We previously reported that excitatory synaptic transmission of the rhomboid nucleus of the bed nucleus of the stria terminalis (BSTrh), a brain region implicated in infanticidal behavior, is reinforced during pubertal development. However, it remains unclear how gonadal steroid hormones mediate this behavioral transition and neural plastic change during pubertal development. Here we revealed that administration of either 17β-estradiol (E2) or <em>5α</em>-dihydrotestosterone (<em>DHT</em>) to gonadectomized mice during pubertal development induced infanticidal behavior in adulthood (about 7 weeks old). Next, we performed whole-cell patch clamp recording in the BSTrh to study the effect of gonadal steroid hormones on neural synaptic transmission. We found that E2 but not <em>DHT</em> administration during pubertal development considerably enhanced excitatory synaptic transmission in the BSTrh by increasing the probability of excitatory neurotransmitter release from the presynaptic terminalis. These data suggest that reinforcement of excitatory synaptic transmission by estrogen-receptor-dependent signaling in the BSTrh during puberty may contribute to the development of infanticidal behavior.

The choroid plexus (CP) epithelium is a unique structure in the brain that forms an interface between the peripheral blood on the basal side and the cerebrospinal fluid (CSF) on the apical side. It is a relevant source of many polypeptides secreted to the CSF with neuroprotective functions and also participates in the elimination and detoxification of brain metabolites, such as β-amyloid (Aβ) removal from the CSF through transporter-mediated influx. The CP is also a target tissue for sex hormones (SHs) that have recognised neuroprotective effects against a variety of insults, including Aβ toxicity and oxidative stress in the central nervous system. The present study aimed to understand how SHs modulate Aβ-induced oxidative stress in a CP cell line (Z310 cell line) by analysing the effects of Aβ1-42 on oxidative stress, mitochondrial function and apoptosis, as well as by assessing how 17β-oestradiol (E2 ) and <em>5α</em>-dihydrotestosterone (<em>DHT</em>) modulated these effects and the cellular uptake of Aβ1-42 by CP cells. Our findings show that E2 and <em>DHT</em> treatment reduce Aβ1-42 -induced oxidative stress and the internalisation of Aβ1-42 by CP epithelial cells, highlighting the importance of considering the background of SHs and therefore sex-related differences in Aβ metabolism and clearance by CP cells.

Benign prostatic hyperplasia (BPH) is a progressive pathological condition associated with proliferation of prostatic tissues, prostate enlargement, and lower-urinary tract symptoms. However, the mechanism underlying the pathogenesis of BPH is unclear. The aim of this study was to investigate the protective effects of a combination of Stauntonia hexaphylla and Cornus officinalis (SC extract) on a testosterone propionate (TP)-induced BPH model. The effect of SC extract was examined in a TP-induced human prostate adenocarcinoma cell line. Male Sprague-Dawley rats were randomly divided into 5 groups (n = 6) for in vivo experiments. To induce BPH, all rats, except those in the control group, were administered daily with subcutaneous injections of TP (5 mg/kg) and orally treated with appropriate phosphate buffered saline/drugs (finasteride/saw palmetto/SC extract) for 4 consecutive weeks. SC extract significantly downregulated the androgen receptor (AR), prostate specific antigen (PSA), and <em>5α</em>-reductase type 2 in TP-induced BPH in vitro. In in vivo experiments, SC extract significantly reduced prostate weight, size, serum testosterone, and dihydrotestosterone (<em>DHT</em>) levels. Histologically, SC extract markedly recovered TP-induced abnormalities and reduced prostatic hyperplasia, thereby improving the histo-architecture of TP-induced BPH rats. SC extract also significantly downregulated AR and PSA expression, as assayed using immunoblotting. Immunostaining revealed that SC extract markedly reduced the <em>5α</em>-reductase type 2 and significantly downregulated the expression of proliferating cell nuclear antigen. In addition, immunoblotting of B-cell lymphoma 2 (Bcl-2) family proteins indicated that SC extract significantly downregulated anti-apoptotic Bcl-2 and markedly upregulated pro-apoptotic B cell lymphoma-associated X (Bax) expression. Furthermore, SC treatment significantly decreased the Bcl-2/Bax ratio, indicating induced prostate cell apoptosis in TP-induced BPH rats. Thus, our findings demonstrated that SC extract protects against BPH by inhibiting <em>5α</em>-reductase type 2 and inducing prostate cell apoptosis. Therefore, SC extract might be useful in the clinical treatment of BPH.

Our study seeks to explore anabolic effects of a periodontal regenerative agent enamel matrix derivative (EMD). Its modulation by nicotine and the anti-oxidant glutathione (GSH) are investigated in human periosteal fibroblasts (HPF) and MG63 osteoblasts. Androgen biomarkers of oxidative stress and healing, resulting from radiolabeled androgen substrates are assayed. This in vitro model simulates a redox environment relevant to the periodontal lesion. It aims to confirm the hypothesis that EMD is an effective regenerative agent in a typically redox environment of the periodontal lesion. Monolayer cultures of MG63 osteoblasts and HPF established in culture medium are incubated with androgen substrates, and optimal concentrations of EMD, nicotine and GSH, alone and in combination. EMD significantly enhances yields of <em>5α</em>-dihydrotestosterone (<em>DHT</em>) an effective bioactive metabolite, alone and in combination with GSH, to overcome oxidative effects of nicotine across cultures. The 'in vitro' findings of this study could be extrapolated to "in vivo" applications of EMD as an adjunctive regenerative therapeutic agent in an environment of chronic inflammation and oxidative stress. Increased yields of <em>DHT</em> implicated in matrix synthesis and direct antioxidant capacity, confirm the potential applications for enamel matrix derivative in periodontal regenerative procedures.

<b>:</b> Benign prostatic hyperplasia (BPH) is one of the major public health concerns, which has a high prevalence rate and causes significant decline in men's quality of life. BPH is highly related to sexual hormone metabolism and aging. In particular, dihydrotestosterone (<em>DHT</em>), to which testosterone is modified by <em>5α</em>-reductase (5AR), has a significant effect on BPH development. <em>DHT</em> binds to an androgen receptor (AR) and steroid receptor coactivator 1 (SRC-1); then, it induces the proliferation of a prostate cell and expression of prostate specific antigen (PSA). <i>Paecilomyces tenuipes</i> (<i>P. tenuipes</i>) is a mushroom that has been popularized by the artificial cultivation of fruiting bodies based on silkworms by researchers from the Republic of Korea. In a previous study, we identified the effect of PE on PSA mRNA expression in LNCaP cells. This suggests that PE may have an inhibitory effect on androgen signaling. Therefore, we confirmed the expression of androgen signaling-related factors, such as AR, SRC-1, and PSA in LNCaP. Furthermore, we confirmed the androgen signaling inhibitory effect of PE using the testosterone propionate (TP)-induced BPH rat model. A BPH rat model was established with a four-week treatment of daily subcutaneous injections of testosterone propionate (TP, 3 mg/kg) dissolved in corn oil after castration. The rats in the treatment group were orally gavaged <i>P. tenuipes</i> extract (PE), finasteride (Fi), or saw palmetto extract (Saw) with TP injection. <em>DHT</em> induced an increase in the expression levels of AR, SRC-1, and PSA proteins in LNCaP cells. On the contrary, the PE treatment reduced the expression levels. In vivo<i>,</i> the BPH group showed an increase in prostate size compared with the control group. The PE gavaged group showed a decrease in prostate size compared with the BPH group. In addition, the protein expressions of AR, 5AR2, and PSA were significantly lower in the PE gavaged group than BPH group in prostate tissue. These results suggest the beneficial effects of PE on BPH via the modulation of AR signaling pathway.

<AbstractText>Stauntonia hexaphylla (Lardizabalaceae, S. hexaphylla) is traditionally used as a folk remedy for alleviating fever and for its anti- inflammatory and analgesic properties. In Korea and China, S. hexaphylla has been used as a traditional medicine that acts as diuretic and analgesic. S. hexaphylla has also been reported to inhibit osteoporosis and aldose reductase activity.</AbstractText><AbstractText>The study aimed to evaluate the therapeutic effects of an extract of S. hexaphylla on testosterone induced benign prostate hyperplasia (BPH) models and to observe its mechanism of action.</AbstractText><AbstractText>To induce a BPH model in vitro and in vivo, a testosterone-treated LNCaP cell line and Sprague Dawley (SD) rats were used, respectively. Androgen receptors (ARs) and prostate-specific antigens (PSA), which are typical BPH-related proteins, were evaluated using western blotting. Prostate weights and dihydrotestosterone (<em>DHT</em>) levels were measured in vivo, and histopathology of the prostate examined using hematoxylin and eosin staining. Proliferating cell nuclear antigen (PCNA) and <em>5α</em>-reductase type 2 were also evaluated via immunohistochemistry (IHC). In addition, TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) staining and LC3 staining of IHC were performed to evaluate apoptosis and autophagy.</AbstractText><AbstractText>S. hexaphylla reduced prostates weights and the thickness of prostate epithelial cells. In vivo and in vitro, PSA and ARs were downregulated following S. hexaphylla treatment. The S. hexaphylla extracts also reduced <em>DHT</em> and <em>5α</em>-reductase type 2 expression. In addition, the expression of PCNA was reduced, and in the TUNEL staining and IHC of LC3, the number of positive cells was increased in the groups treated with S. hexaphylla.</AbstractText><AbstractText>It was observed that extracts of S. hexaphylla inhibited both <em>5α</em> -reductase type 2 and ARs. The results indicate that the use of S. hexaphylla extract in BPH is probably beneficial through <em>5α</em>-reductase inhibition and α-adrenergic receptor blockade. In addition, apoptosis and autophagy were induced, and PCNA was downregulated after S. hexaphylla treatment. Therefore, it can be concluded that S. hexaphylla has a therapeutic effect on BPH.</AbstractText>

This study addresses first the role of human 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1) in breast cancer (BC) cells. The enzyme has a high estrone-activating activity that is subject to strong substrate inhibition as shown by enzyme kinetics at the molecular level. We used BC cells to verify this phenomenon in living cells: estrone concentration increase did reduce the reaction with 0.025 to 4μM substrate. Moreover, <em>5α</em>-dihydrotestosterone (<em>DHT</em>) demonstrated some inhibition of estrogen activation at both the molecular and cellular levels. The presence of <em>DHT</em> did not change the tendency toward substrate inhibition for estrone conversion, but shifted the inhibition toward higher substrate concentrations. Moreover, a binding study demonstrated that both <em>DHT</em> and dehydroepiandrosterone (DHEA) can be bound to the enzyme, thereby supporting the multi-specificity of 17β-HSD1. We then followed the concentrations of estradiol and performed q-RT-PCR measurements of reductive 17β-HSDs after 17β-HSD1 inhibition. The estradiol decrease by the 17β-HSD1 inhibition was demonstrated lending support to this observation. Knockdown and inhibition of 17β-HSD1 produced reduction in estradiol levels and the down-regulation of another reductive enzyme 17β-HSD7, thus "amplifying" the reduction of estradiol by the 17β-HSD1 modulation itself. The critical positioning of 17β-HSD7 in sex-hormone-regulation as well as the mutual regulation of steroid enzymes via estradiol in BC, are clearly demonstrated. Our study demonstrates that fundamental enzymological mechanisms are relevant in living cells. Moreover, further enzyme study in cells is merited to advance biological and medical research. We also demonstrated the central role of 17β-HSD7 in sex-hormone conversion and regulation, supporting it as a novel target for estrogen-dependent (ER+) BC.

Androgen hormones are important compounds related to body composition and exercise performance in athletes. The intake of <i>Dioscorea esculenta</i>, known as lesser yam, contains diosgenin and resistance training have been shown to normalize the secretion of androgen hormones. This study aimed to clarify the level of androgen hormone secretion and the effects of <i>Dioscorea esculenta</i> intake with resistance training on muscle hypertrophy and strength in athletes. First, in a cross-sectional study, we compared the serum androgen hormone [dehydroepiandrosterone (DHEA), testosterone, and <em>5α</em>-dihydrotestosterone (<em>DHT</em>)] levels between sprint athletes (<i>n</i> = 15) and non-athletes (<i>n</i> = 15). Second, in an 8-week intervention study, sprint athletes were randomly divided into 2 groups: resistance training with placebo (<i>n</i> = 8) or with <i>Dioscorea esculenta</i> (2,000 mg/day) intake (<i>n</i> = 7). The serum DHEA, free testosterone, and <em>DHT</em> levels were lower in athletes than in non-athletes. <i>Dioscorea esculenta</i> intake combined with resistance training increased the arm fat-free mass, the 1 repetition maximum of deadlift and snatch, and the serum DHEA, free testosterone, and <em>DHT</em> levels, compared with resistance training and placebo intake. The results suggested that <i>Dioscorea esculenta</i> intake combined with resistance training has further effects on muscle hypertrophy and strength in athletes by restoring secretion of androgen hormones.

<strong class="sub-title"> Keywords: </strong> <em>5α</em>-dihydrotestosterone; Dioscorea esculenta; muscle hypertrophy; resistance training; sprint athletes.

Effect-directed analysis (EDA) that combines effect-based methods (EBMs) with high-performance thin-layer chromatography (HPTLC) is a useful technique for spatial, temporal, and process-related effect evaluation and may provide a link between effect testing and responsible substance identification. In this study, a yeast multi endocrine-effect screen (YMEES) for the detection of endocrine effects is combined with HPTLC. Simultaneous detection of estrogenic, androgenic, and gestagenic effects on the HPTLC plate is achieved by mixing different genetically modified Arxula adeninivorans yeast strains, which contain either the human estrogen, androgen, or progesterone receptor. Depending on the yeast strain, different fluorescent proteins are formed when an appropriate substance binds to the specific hormone receptor. This allows to measure hormonal effects at different wavelengths. Two yeast cell application approaches, immersion and spraying, are compared. The sensitivity and reproducibility of the method are shown by dose-response investigations for reference compounds. The spraying approach indicated similar sensitivities and higher precisions for the tested hormones compared to immersion. The EC₁₀s for estrone (E1), 17β-estradiol (E2), 17α-ethinylestradiol (EE2), <em>5α</em>-dihydrotestosterone (<em>DHT</em>), and progesterone (P4) were 95, 1.4, 10, 7.4, and 15 pg/spot, respectively. Recovery rates of E1, E2, EE2, <em>DHT</em>, and P4 between 88 and 120% show the usability of the general method in combination with sample enrichment by solid phase extraction (SPE). The simultaneous detection of estrogenic, androgenic, and gestagenic effects in wastewater and surface water samples demonstrates the successful application of the YMEES in such matrices. This promising method allows us to identify more than one endocrine effect on the same HPTLC plate, which saves time and material. The method could be used for comparison, evaluation, and monitoring of different river sites and wastewater treatment steps and should be tested in further studies.

Keywords: Androgen; Effect-directed analysis (EDA); Estrogen; Gestagen; High-performance thin-layer chromatography (HPTLC); Yeast multi endocrine-effect screen (YMEES).

Gonadal development in medaka (Oryzias latipes) is dependent on the synergy between estrogens and androgens. Disruption of steroid hormone levels can lead to ovo-testis. To determine the sensitive windows for hormonally induced sex reversal in medaka, we developed a novel 42sp50-GFP_ChgH-GFP transgenic medaka line, allowing the identification of female gonadal tissue by fluorescence present in developing oocytes. Germinal transgenesis resulted in a stable line exhibiting strong GFP signal constitutively in the ovaries and in the liver in response to estrogens. The sensitivity of this line to disruption of sex determination following 16-day chronic exposures was in the ng/L range. To identify the developmental period sensitive to exogenous agents, fry were exposed to 24 h pulses of high concentrations of 17β-estradiol (E2) or <em>5α</em>-dihydrotestosterone (<em>DHT</em>) at various time points between day post fertilisation (DPF) 0 and 12. Evaluation of phenotype followed by genotyping at DPF 16, revealed sensitivity to E2 between DPF 1-8 and two periods of susceptibility to <em>DHT</em> between DPF 0-1 and DPF 4-8. No phenotypic sex reversal was detected after exposure to <em>DHT</em> or E2 on DPF 11 or 12. The observed effects persist to at least DPF 24. The identified sensitive embryonic time periods for disruption of sex determination will aid future research on sex determination and the development of screening assays using early embryonic life stages. This article is protected by copyright. All rights reserved.

In women, hormonal fluctuations related to the menstrual cycle may impose a great source of variability for some biomarkers of testosterone (T) administration, which can ultimately disrupt the sensitivity of their longitudinal monitoring. In this study, the sensitivity of the current urinary and haematological markers of the Athlete Biological Passport (ABP), as well as serum steroid biomarkers was investigated for the monitoring of a 28-days T gel treatment combined with endogenous fluctuation of the menstrual cycle in 14 healthy female subjects. Additionally, the analysis of urinary target compounds was performed on a subset of samples for endogenous/exogenous origin via isotope ratio mass spectrometry (IRMS). In serum, concentrations of T and dihydrotestosterone (<em>DHT</em>) increased significantly during the treatment, whereas in urine matrix the most affected biomarkers were found to be the ratios of testosterone/epitestosterone (T/E) and <em>5α</em>-androstane-3α,17β-diol/epitestosterone (<em>5α</em>Adiol/E). The detection capability of both urinary biomarkers was heavily influenced by [E], which fluctuated depending on the menstrual cycle, and resulted in low sensitivity of the urinary steroidal ABP module. On the contrary, an alternative approach by the longitudinal monitoring of serum T and <em>DHT</em> concentrations with the newly proposed T/androstenedione ratio showed higher sensitivity. The confirmatory IRMS results demonstrated that less than one third of the tested urine samples fulfilled the criteria for positivity. Results from this study demonstrated that the 'blood steroid profile' represents a powerful complementary approach to the 'urinary module' and underlines the importance of gathering bundle of evidence to support the scenario of an endogenous prohibited substance administration.

Keywords: Athlete Biological Passport; menstrual cycle; steroid profile; testosterone gel; women.

<AbstractText>The extraction of salient information from the environment is modulated by the activation of dopamine receptors. Using rodent models, we previously reported that gating deficits caused by dopamine receptor activation - as measured by the prepulse inhibition (PPI) of startle - are effectively opposed by inhibitors of the steroidogenic enzyme <em>5α</em>-reductase (<em>5α</em>R). The specific <em>5α</em>R isoenzyme and steroids implicated in these effects, however, remain unknown.</AbstractText><p><div><b>METHODS</b></div>The effects of the selective D₁ dopamine receptor agonist SKF-82958 (SKF, 0.3 mg/kg, IP) and D₂ receptor agonist quinpirole (QUIN, 0.5 mg/kg, IP) were tested in the startle reflex and PPI of knockout (KO) mice for either <em>5α</em>R type 1 (<em>5α</em>R1) or type 2 (<em>5α</em>R2). Furthermore, we established whether these effects may be modified by the <em>5α</em>-reduced steroids dihydroprogesterone (DHP), allopregnanolone (AP), dihydrotestosterone (<em>DHT</em>), <em>5α</em>-androstane-3α,17β-diol (3α-diol), or androsterone. To test the mechanisms whereby <em>5α</em>R products may alter the PPI-disrupting properties of D₁ agonists, we studied the involvement of GABA-A and PXR, two receptors targeted by neuroactive steroids. Specifically, we tested the effects of SKF in combination with the GABA-A antagonist bicuculline, as well as in KO mice for the GABA-A δ subunit and PXR.</p><AbstractText><em>5α</em>R1, but not <em>5α</em>R2, knockout (KO) mice were insensitive to the PPI-disrupting effects of SKF. This sensitivity was reinstated by AP (3 mg/kg, IP), but not other <em>5α</em>-reduced steroids. The PPI deficits induced by SKF were not modified by bicuculline, δ-subunit KO mice and PXR KO mice.</AbstractText><p><div><b>CONCLUSIONS</b></div>These results collectively suggest that <em>5α</em>R1 enables the negative effects of D₁ dopamine receptor activation on information processing via production of AP. The contribution of AP to the PPI-disrupting mechanisms of D₁ receptor agonists, however, do not appear to be mediated by either GABA-A or PXR receptors.</p>

Steroid receptors (SRs) are a closely related family of ligand-dependent nuclear receptors that mediate the transcription of genes critical for development, reproduction and immunity. SR dysregulation has been implicated in cancer, inflammatory diseases and metabolic disorders. SRs bind their cognate hormone ligand with exquisite specificity, offering a unique system to study the evolution of molecular recognition. The SR family evolved from an estrogen-sensitive ancestor and diverged to become sensitive to progestagens, corticoids and, most recently, androgens. To understand the structural mechanisms driving the evolution of androgen responsiveness, the ancestral androgen receptor (ancAR1) was crystallized in complex with <em>5α</em>-dihydrotestosterone (<em>DHT</em>) and a fragment of the transcriptional mediator/intermediary factor 2 (Tif2). Crystals diffracted to 2.1 Å resolution and the resulting structure will permit a direct comparison with its progestagen-sensitive ancestor, ancestral steroid receptor 2 (AncSR2).

Medroxyprogesterone acetate (MPA) has widely been used in hormone replacement therapy (HRT), and is associated with an increased risk of breast cancer, possibly due to disruption of androgen receptor (AR) signaling. In contrast, the synthetic HRT Tibolone does not increase breast density, and is rapidly metabolized to estrogenic 3α-OH-tibolone and 3β-OH-tibolone, and a delta-4 isomer (Δ(4)-TIB) that has both androgenic and progestagenic properties. Here, we show that <em>5α</em>-dihydrotestosterone (<em>DHT</em>) and Δ(4)-TIB, but not MPA, stabilize AR protein levels, initiate specific AR intramolecular interactions critical for AR transcriptional regulation, and increase proliferation of AR positive MDA-MB-453 breast cancer cells. Structural modeling and molecular dynamic simulation indicate that Δ(4)-TIB induces a more stable AR structure than does <em>DHT</em>, and MPA a less stable one. Microarray expression analyses confirms that the molecular actions of Δ(4)-TIB more closely resembles <em>DHT</em> in breast cancer cells than either ligand does to MPA.

Numerous anthropogenic sources, such as pulp mill and sewage treatment effluents, contain androgenic endocrine disrupting compounds that alter the reproductive status of aquatic organisms. The current study injected adult male mummichog (Fundulus heteroclitus) with 0 (control), 1 pg/g, 1 ng/g or 1 μg/g body weight of the model androgen <em>5α</em>-dihydrotestosterone (<em>DHT</em>) with the intent to induce a period of plasma sex hormone depression, a previously-observed effect of <em>DHT</em> in fish. A suite of gonadal steroidogenic genes were assessed during sex hormone depression and recovery. Fish were sampled 6, 12, 16, 18, 24, 30 and 36 h post-injection, and sections of testis tissue were either snap frozen immediately or incubated for 24 h at 18 °C to determine in vitro gonadal hormone production and then frozen. Plasma testosterone (T) and 11-ketotestosterone (11KT) were depressed beginning 24 h post-injection. At 36 h post-injection plasma T remained depressed while plasma 11KT had recovered. In snap frozen tissue there was a correlation between plasma sex hormone depression and downregulation of key steroidogenic genes including steroidogenic acute regulatory protein (star), cytochrome P450 17a1 (cyp17a1), 3β-hydroxysteroid dehydrogenase (3βhsd), 11β-hydroxysteroid dehydrogenase (11βhsd) and 17β-hydroxysteroid dehydrogenase (17βhsd). Similar to previous studies, 3βhsd was the first and most responsive gene during <em>DHT</em> exposure. Gene responses from in vitro tissue were more variable and included the upregulation of 3βhsd, 11βhsd and star during the period of hormone depression. The differential expression of steroidogenic genes from the in vitro testes compared to the snap frozen tissues may be due to the lack of regulators from the hypothalamo-pituitary-gonadal axis present in whole-animal systems. Due to these findings it is recommended to use snap frozen tissue, not post-incubation tissue from in vitro analysis, for gonadal steroidogenic gene expression to more accurately reflect in vivo responses.

Wildlife inhabiting urban environments exhibit drastic changes in morphology, physiology, and behavior. It has often been argued that these phenotypic responses could be the result of micro-evolutionary changes following the urbanization process. However, other mechanisms such as phenotypic plasticity, maternal effects, and developmental plasticity could be involved as well. To address maternal effects as potential mechanisms, we compared maternal hormone and antibody concentrations in eggs between city and forest populations of European blackbirds (<i>Turdus merula</i>), a widely distributed species for which previous research demonstrated differences in behavioral and physiological traits. We measured egg and yolk mass, yolk concentrations of androgens (androstenedione [A₄], testosterone [T], <em>5α</em>-dihydrotestosterone [<em>5α</em>-<em>DHT</em>], and immunoglobulins [IgY]) and related them to population, clutch size, laying order, embryo sex, and progress of breeding season. We show (a) earlier onset of laying in the city than forest population, but similar egg and clutch size; (b) higher overall yolk androgen concentrations in the forest than the city population (sex-dependent for T); (c) greater among-female variation of yolk T and <em>5α</em>-<em>DHT</em> concentrations in the forest than city population, but similar within-clutch variation; (d) similar IgY concentrations with a seasonal decline in both populations; and (e) population-specific positive (city) or negative (forest) association of yolk A₄ and T with IgY concentrations. Our results are consistent with the hypotheses that hormone-mediated maternal effects contribute to differences in behavioral and physiological traits between city and forest individuals and that yolk androgen and immunoglobulin levels can exhibit population-specific relationships rather than trade-off against each other.

Dihydrotestosterone (<em>DHT</em>) and 17β-estradiol (E2) are sex hormones that regulate human hair follicle (HF) growth and are produced by peripheral reduction and aromatization of testosterone. However, the expression patterns of <em>DHT</em> and E2 synthesis-related proteins and their receptors in male yak skin during different HF stages (telogen, anagen, and catagen) are unknown. In this study, we found that both <em>5α</em>-red and androgen receptor (AR) were expressed in epithelial cells and AR was expressed in the dermal papilla. Additionally, the transcription level of <em>5α</em>-red1 at different HF stages was significantly higher than that of <em>5α</em>-red2 mRNA at the same stage; <em>5α</em>-red1 and <em>5α</em>-red2 proteins peaked during the anagen and telogen periods of HF, respectively. However, AR protein was only expressed in the skin during the anagen phase of HF. Aromatase and estrogen receptors (ERα and ERβ) were expressed in cutaneous epithelial cells, whereas ERα and ERβ were expressed in the dermal papilla; the transcription level of ERα in HFs at each stage was much higher than that of ERβ. From the catagen to telogen phase, aromatase protein expression was down-regulated, while ERα protein expression was up-regulated. Based on our results, we speculate that <em>5α</em>-red1 is essential for the synthesis of <em>DHT</em> in male yak skin epithelial cells and promotes the growth of HFs through AR. E2 synthesized by male yak skin epithelial cells may inhibit the growth of male yak skin HFs by ERα. These results provide a foundation for further study on the mechanism of hormone-regulated male yak skin HFs.

The pharmaceutical 17α-ethynylestradiol (EE2) is considered as an endocrine-disrupting chemical that interferes with male reproduction and hormonal activation. In this study, we investigated the molecular mechanism underlying EE2-regulatory testosterone release in vitro and in vivo. The results show that EE2 treatment decreased testosterone release from rat Leydig cells. Treatment of rats with EE2 reduced plasma testosterone levels and decreased the sensitivity of human chorionic gonadotropin (hCG). EE2 reduced luteinizing hormone receptor (LHR) expression associated with decreased cAMP generation by downregulation of adenylyl cyclase activity and decreased intracellular calcium-mediated pathways. The expression levels of StAR and P450scc were decreased in Leydig cells by treatment of rats with EE2 for 7 days. The sperm motility in the vas deferens and epididymis was reduced, but the histopathological features of the testis and the total sperm number of the vas deferens were not affected. Moreover, the serum dihydrotestosterone (<em>DHT</em>) level was decreased by treatment with EE2. The prostate gland and seminal vesicle atrophied significantly, and their expression level of <em>5α</em>-reductase type II was reduced after EE2 exposure. Taken together, these results demonstrate an underlying mechanism of EE2 to downregulate testosterone production in Leydig cells, explaining the damaging effects of EE2 on male reproduction.

Investigations of endocrine disrupting chemicals found in aquatic ecosystems with estrogenic and androgenic modes of action have increased over the past two decades due to a surge of evidence of adverse effects in wildlife. Chemicals that disrupt androgen signalling and steroidogenesis can result in an imbalanced conversion of testosterone (T) into 17β-estradiol (E2) and other androgens such as <em>5α</em>-dihydrotestosterone (<em>5α</em>-<em>DHT</em>). Therefore, a better understanding of how chemicals perturb these pathways is warranted. In this study, the brain, liver, and testes of Silurana tropicalis were exposed ex vivo to the human drug finasteride, a potent steroid <em>5α</em>-reductase inhibitor and a model compound to study the inhibition of the conversion of T into <em>5α</em>-<em>DHT</em>. These experiments were conducted (1) to determine organ specific changes in sex steroid production after treatment, and (2) to elucidate the transcriptomic response to finasteride in testicular tissue. Enzyme-linked immunosorbent assays were used to measure hormone levels in media following finasteride incubation for 6 h. Finasteride significantly increased T levels in the media of liver and testis tissue, but did not induce any changes in E2 and <em>5α</em>-<em>DHT</em> production. Gene expression analysis was performed in frog testes and data revealed that finasteride treatment significantly altered 1,434 gene probes. Gene networks associated with male reproduction such as meiosis, hormone biosynthesis, sperm entry, gonadotropin releasing hormone were affected by finasteride exposure as well as other pathways such as oxysterol synthesis, apoptosis, and epigenetic regulation. For example, this study suggests that the mode of action by which finasteride induces cellular damage in testicular tissue as reported by others, is via oxidative stress in testes. This data also suggests that 5-reductase inhibition disrupts the expression of genes related to reproduction. It is proposed that androgen-disrupting chemicals may mediate their action via 5-reductases and that the effects of environmental pollutants are not limited to the androgen receptor signalling.

The impact of the perfluoro-chemical, perfluorooctanesulfonate (PFOS), on gonadal steroidogenesis during sexual differentiation in Silurana tropicalis was examined because of its ubiquity in the environment, bioaccumulative nature and potential to disturb endocrine activity. A partial life cycle study exposing S. tropicalis to varying concentrations of PFOS 0.06, 0.13, 0.25, 0.50 and 1.0 mg PFOS/L [nominal]) was conducted. Gonad and plasma samples were collected from juvenile control specimens and organisms exposed to PFOS from early embryo through 150 days post-metamorphosis. Gonad CYP17, aromatase and <em>5α</em>-reductase activities were measured. Plasma estradiol, testosterone, dihydrotestosterone (<em>DHT</em>) and gonadal testosterone were measured in both males and females. Increased plasma <em>DHT</em> and gonadal testosterone were found in PFOS-treated juvenile male S. tropicalis compared to controls. Decreased plasma estradiol, but not testosterone, was detected in PFOS-treated female S. tropicalis compared to controls. Plasma <em>DHT</em> was not detected and an increase in gonadal testosterone was detected in PFOS-treated female frogs. Female S. tropicalis exposed to PFOS exhibited a concentration-related decrease in the mean aromatase activity, but not <em>5α</em>-reductase. PFOS exposure in male frogs induced a concentration-related increase in <em>5α</em>-reductase activity, but did not alter aromatase activity compared to control frogs. A concentration-related increase in CYP 17,20-lyase activity, but not 17-hydroxylase activity, was found in both female and male S. tropicalis exposed to PFOS.

Effects of increase in muscle <em>5α</em>-dihydrotestosterone (<em>DHT</em>) levels caused by resistance exercise on regulation of mammalian target of rapamycin (mTOR)- and glucose transporter 4 (GLUT4)-signaling pathways in type 2 diabetic rats were assessed. Twenty-week-old type 2 diabetic rats were randomly divided into the resting control, immediately, 1 hour, or 3 hours after resistance exercise, with or without the pretreatment of <em>5α</em>-reductase inhibitor. Immediately or 1 hour after exercise, levels of <em>5α</em>-reductase and <em>DHT</em> as well as phosphorylation levels of AMP-activated protein kinase (AMPK), TBC1 domain family member 1 (TBC1D1), and protein kinase B (Akt) in muscle were significantly elevated. Phosphorylation of muscle Akt substrate of 160 kDa (AS160) and translocation levels of GLUT4 at 1 and 3 hours after resistance exercise were significantly elevated. Additionally, resistance exercise significantly activated the phosphorylation of muscle mTOR immediately, and at 1 and 3 hours and of p70 ribosomal S6 kinase (p70S6K) at 1 and 3 hours. However, pretreatment with the <em>5α</em>-reductase inhibitor significantly attenuated the exercise-induced activation of Akt/mTOR/p70S6K and Akt/AS160/GLUT4 signaling, but did not affect AMPK/TBC1D1/GLUT4 signaling. These findings suggest that resistance exercise-induced increase in muscle <em>DHT</em> synthesis may contribute to activation of Akt/mTOR/p70S6K- and Akt/AS160/GLUT4 signaling pathways in type 2 diabetic rats.

Keywords: androgen; diabetes; exercise; glucose metabolism; muscle protein synthesis.