Structure-function of human 3 alpha-hydroxysteroid dehydrogenases: genes and proteins

Developmental and adult stress: effects of steroids and neurosteroids

In humans, exposure to early life adversity has profound implications for susceptibility to developing neuropsychiatric disorders later in life. Studies in rodents have shown that stress experienced during early postnatal life can have lasting effects on brain development. Glucocorticoids and sex steroids are produced in endocrine glands and the brain from cholesterol; these molecules bind to nuclear and membrane-associated steroid receptors. Unlike other steroids that can also be made in the brain, neurosteroids bind specifically to neurotransmitter receptors, not steroid receptors. The relationships among steroids, neurosteroids, and stress are multifaceted and not yet fully understood. However, studies demonstrating altered levels of progestogens, androgens, estrogens, glucocorticoids, and their neuroactive metabolites in both developmental and adult stress paradigms strongly suggest that these molecules may be important players in stress effects on brain circuits and behavior. In this review, we discuss the influence of developmental and adult stress on various components of the brain, including neurons, glia, and perineuronal nets, with a focus on sex steroids and neurosteroids. Gaining an enhanced understanding of how early adversity impacts the intricate systems of brain steroid and neurosteroid regulation could prove instrumental in identifying novel therapeutic targets for stress-related conditions.

Differential RNA editing landscapes in host cell versus the SARS-CoV-2 genome

The SARS-CoV-2 pandemic was defined by the emergence of new variants formed through virus mutation originating from random errors not corrected by viral proofreading and/or the host antiviral response introducing mutations into the viral genome. While sequencing information hints at cellular RNA editing pathways playing a role in viral evolution, here, we use an in vitro human cell infection model to assess RNA mutation types in two SARS-CoV-2 strains representing the original and the alpha variants. The variants showed both different cellular responses and mutation patterns with alpha showing higher mutation frequency with most substitutions observed being C-U, indicating an important role for apolipoprotein B mRNA editing catalytic polypeptide-like editing. Knockdown of select APOBEC3s through RNAi increased virus production in the original virus, but not in alpha. Overall, these data suggest a deaminase-independent anti-viral function of APOBECs in SARS-CoV-2 while the C-U editing itself might function to enhance genetic diversity enabling evolutionary adaptation.

Progesterone signaling in the regulation of luteal steroidogenesis

The corpus luteum is the major source of progesterone, the essential hormone for female reproductive function. While progesterone activity has been the subject of extensive research for decades, characterization of non-canonical progesterone receptor/signaling pathways provided a new perspective for understanding the complex signal transduction mechanisms exploited by the progesterone hormone. Deciphering these mechanisms has significant implications in the management of luteal phase disorders and early pregnancy complications. The purpose of this review is to highlight the complex mechanisms through which progesterone-induced signaling mediates luteal granulosa cell activity in the corpus luteum. Here, we review the literature and discuss the up-to-date evidence on how paracrine and autocrine effects of progesterone regulate luteal steroidogenic activity. We also review the limitations of the published data and highlight future research priorities.

The prognosis of lipid reprogramming with the HMG-CoA reductase inhibitor, rosuvastatin, in castrated Egyptian prostate cancer patients: Randomized trial

AIM

The role of surgical castration and rosuvastatin treatment on lipid profile and lipid metabolism related markers was evaluated for their prognostic significance in metastatic prostate cancer (mPC) patients.

METHODS

A total of 84 newly diagnosed castrated mPC patients treated with castration were recruited and divided into two groups: Group I served as control (statin non-users) while group II treated with Rosuvastatin (20 mg/day) for 6 months and served as statin users. Prostate specific antigen (PSA), epidermal growth factor receptor (EGFR), Caveolin-1 (CAV1), lipid profile (LDL, HDL, triglycerides (TG) and total cholesterol (TC)) and lipid metabolism related markers (aldoketoreductase (AKR1C4), HMG-CoA reductase (HMGCR), ATP-binding cassette transporter A1 (ABCA1), and soluble low density lipoprotein receptor related protein 1 (SLDLRP1)) were measured at baseline, after 3 and 6 months. Overall survival (OS) was analyzed by Kaplan-Meier and COX regression for prognostic significance.

RESULTS

Before castration, HMG-CoA reductase was elevated in patients <65 years (P = 0.009). Bone metastasis was associated with high PSA level (P = 0.013), but low HMGCR (P = 0.004). Patients with positive family history for prostate cancer showed high levels of EGFR, TG, TC, LDL, alkaline phosphatase (ALP), but low AKR1C4, SLDLRP1, CAV1 and ABCA-1 levels. Smokers had high CAV1 level (P = 0.017). After 6 months of castration and rosuvastatin administration, PSA, TG, LDL and TC were significantly reduced, while AKR1C4, HMGCR, SLDLRP1, CAV1 and ABCA-1 were significantly increased. Overall survival was reduced in patients with high baseline of SLDLRP1 (>3385 pg/ml, P = 0.001), PSA (>40 ng/ml, P = 0.003) and CAV1 (>4955 pg/ml, P = 0.021).

CONCLUSION

Results of the current study suggest that the peripheral lipidogenic effects of rosuvastatin may have an impact on the treatment outcome and survival of castrated mPC patients.

TRAIL REGISTRATION

This trial was registered at the Pan African Clinical Trial Registry with identification number PACTR202102664354163 and at ClinicalTrials.gov with identification number NCT04776889.

Development of 3α,7α-dihydroxy-6α-ethyl-24-nor-5β-cholan-23-sulfate sodium salt (INT-767): Process optimization, synthesis and characterization of metabolites

Herein we report our synthetic efforts in supporting the development of the bile alcohol sulfate INT-767, a FXR/TGR5 dual agonist with remarkable therapeutic potential for liver disorders. We describe the process development to a final route for large scale preparation and analogues synthesis. Key sequences include Grignard addition, a one-pot two-step shortening-reduction of the carboxylic side chain, and the final sulfation reaction. The necessity for additional steps such as the protection/deprotection of hydroxyl groups at the steroidal body was also evaluated for step-economy and formation of side-products. Critical bottlenecks such as the side chain degradation have been tackled using flow technology before scaling-up individual steps. The final synthetic route may be successfully employed to produce the amount of INT-767 required to support late-stage clinical development of the compound. Furthermore, potential metabolites have been synthesized, characterized and evaluated for their ability to modulate FXR and TGR5 receptors providing key reference standards for future drug investigations, as well as offering further insights into the structure-activity relationships of this class of compounds.

Neuropeptidergic control of neurosteroids biosynthesis

Neurosteroids are steroids synthesized within the central nervous system either from cholesterol or by metabolic reactions of circulating steroid hormone precursors. It has been suggested that neurosteroids exert pleiotropic activities within the central nervous system, such as organization and activation of the central nervous system and behavioral regulation. It is also increasingly becoming clear that neuropeptides exert pleiotropic activities within the central nervous system, such as modulation of neuronal functions and regulation of behavior, besides traditional neuroendocrinological functions. It was hypothesized that some of the physiological functions of neuropeptides acting within the central nervous system may be through the regulation of neurosteroids biosynthesis. Various neuropeptides reviewed in this study possibly regulate neurosteroids biosynthesis by controlling the activities of enzymes that catalyze the production of neurosteroids. It is now required to thoroughly investigate the neuropeptidergic control mechanisms of neurosteroids biosynthesis to characterize the physiological significance of this new neuroendocrinological phenomenon.

Ferroptosis-Related Gene Contributes to Immunity, Stemness and Predicts Prognosis in Glioblastoma Multiforme

Ferroptosis, a recently discovered regulated programmed cell death, is associated with tumorigenesis and progression in glioblastoma. Based on widely recognized ferroptosis-related genes (FRGs), the regulation of ferroptosis patterns and corresponding characteristics of immune infiltration of 516 GBM samples with GSE13041, TCGA-GBM, and CGGA-325 were comprehensively analyzed. Here, we revealed the expression, mutations, and CNV of FRGs in GBM. We identified three distinct regulation patterns of ferroptosis and found the hub genes of immunity and stemness among DEGs in three patterns. A prognostic model was constructed based on five FRGs and verified at the mRNA and protein level. The risk score can not only predict the prognosis but also the degree of immune infiltration and ICB responsiveness by functional annotation. The overall assessment of FRGs in GBM patients will guide the direction of improved research and develop new prognostic prediction tools.

Overview of human 20 alpha-hydroxysteroid dehydrogenase (AKR1C1): Functions, regulation, and structural insights of inhibitors

Human aldo-keto reductase family 1C1 (AKR1C1) is an important enzyme involved in human hormone metabolism, which is mainly responsible for the metabolism of progesterone in the human body. AKR1C1 is highly expressed and has an important relationship with the occurrence and development of various diseases, especially some cancers related to hormone metabolism. Nowadays, many inhibitors against AKR1C1 have been discovered, including some synthetic compounds and natural products, which have certain inhibitory activity against AKR1C1 at the target level. Here we briefly reviewed the physiological and pathological functions of AKR1C1 and the relationship with the disease, and then summarized the development of AKR1C1 inhibitors, elucidated the interaction between inhibitors and AKR1C1 through molecular docking results and existing co-crystal structures. Finally, we discussed the design ideals of selective AKR1C1 inhibitors from the perspective of AKR1C1 structure, discussed the prospects of AKR1C1 in the treatment of human diseases in terms of biomarkers, pre-receptor regulation and single nucleotide polymorphisms, aiming to provide new ideas for drug research targeting AKR1C1.

Developmental Considerations for the Use of Naltrexone in Children and Adolescents

Naltrexone (NTX) is a well-tolerated drug with a wide safety margin and mechanism of action that affords use across a wide variety of indications in adults and children. By antagonizing the opioid reward system, NTX can modulate behaviors that involve compulsivity or impulsivity, such as substance use, obesity, and eating disorders. Evidence regarding the disposition and efficacy of NTX is mainly derived from adult studies of substance use disorders and considerable variability exists. Developmental changes, plausible disease-specific alterations and genetic polymorphisms in NTX disposition, and pharmacodynamic pathways should be taken into consideration when optimizing the use of NTX in the pediatric population. This review highlights the current state of the evidence and gaps in knowledge regarding NTX to facilitate evidence-based pharmacotherapy of mental health conditions, for which few pharmacologic options exist.

Membrane protein of SARS-CoV-2 plays a pivotal role in the availability of active testosterone through its interaction with AKR1C2 enzyme leading to the upregulation of TMPRSS2 protease expression

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the coronavirus disease (COVID-19) and ongoing pandemic that has devastated humankind. During the COVID-19 pandemic, it was noticed that the mortality rate in men is higher than that in women. The membrane (M) protein of SARS-CoV-2 plays a pivotal role in the viral life cycle regulating intracellular trafficking and processing of spike (S) protein. In infected individuals, M protein inhibits the conversion of active testosterone to its inactive form through its interaction with Aldo-keto reductase family 1 member C2 (AKR1C2) protein. This leads to the high availability of active testosterone and boosts the formation of its complex with an androgen receptor that in turn promotes the transcription of the transmembrane protease serine 2 (TMPRSS2) gene. TMPRSS2 is known to play a pivotal role in the priming of S protein that is necessary for the SARS-CoV-2 entry into the host cell. Therefore, the interaction of the M protein of SARSCoV-2 with AKR1C2 eventually leads to the upregulation of the transcription of the TMPRSS2 gene that results in an enhanced viral infection and in turn higher mortality in men. The interaction of M protein with AKR1C2 could be a possible target for SARSCoV-2 antiviral drug design.

The insensitive mechanism of poultry to zearalenone: A review

Zearalenone (ZEN) is one of the most common contaminating mycotoxins and is mainly produced by Fusarium graminearum. ZEN and its metabolites can interfere with estrogen function and affect animals' reproductive ability. Pigs are most susceptible to ZEN, and ZEN is less harmful to poultry than to pigs. The exact mechanism for the difference in susceptibility remains unclear. In this review, we summarized some possible reasons for the relative insensitivity of poultry to ZEN, such as the lower total amount of α-zearalenol (α-ZOL) and the α-ZOL-to-β-ZOL ratio which reduce the toxicity of ZEN to poultry. The faster hepatic and enteric circulation, and excretion capacity in poultry can excrete more ZEN and its metabolites. There are other possible factors such as the transformation of intestinal microorganisms, differences in hydroxysteroid dehydrogenases' activity, high estrogen levels, and low estrogen receptors affinity which can also cause poultry to be relatively insensitive to ZEN. In this review, we summarized the hazards, pollution status, metabolic pathways, and some measures to mitigate ZEN's harmfulness. Specifically, we discussed the possible mechanisms of low reproductive toxicity by ZEN in poultry.

Biosynthesis and signalling functions of central and peripheral nervous system neurosteroids in health and disease

Neurosteroids are steroid hormones synthesised de novo in the brain and peripheral nervous tissues. In contrast to adrenal steroid hormones that act on intracellular nuclear receptors, neurosteroids directly modulate plasma membrane ion channels and regulate intracellular signalling. This review provides an overview of the work that led to the discovery of neurosteroids, our current understanding of their intracellular biosynthetic machinery, and their roles in regulating the development and function of nervous tissue. Neurosteroids mediate signalling in the brain via multiple mechanisms. Here, we describe in detail their effects on GABA (inhibitory) and NMDA (excitatory) receptors, two signalling pathways of opposing function. Furthermore, emerging evidence points to altered neurosteroid function and signalling in neurological disease. This review focuses on neurodegenerative diseases associated with altered neurosteroid metabolism, mainly Niemann-Pick type C, multiple sclerosis and Alzheimer disease. Finally, we summarise the use of natural and synthetic neurosteroids as current and emerging therapeutics alongside their potential use as disease biomarkers.

5alpha-dihydroprogesterone promotes proliferation and migration of human glioblastoma cells

Glioblastomas (GBMs) are the most common and deadliest intracranial tumors. Steroid hormones, such as progesterone (P4), at physiological concentrations, promote proliferation, and migration of human GBM cells in vivo and in vitro. Neuronal and glial cells, but also GBMs, metabolize P4 and synthesize different active metabolites such as 5α-dihydroprogesterone (5α-DHP). However, their contribution to GBM malignancy remains unknown. Here, we determined the 5α-DHP effects on the number of cells, proliferation, and migration of the U87 and U251 human GBM-derived cell lines. Of the tested concentrations (1 nM-1 µM), 5α-DHP 10 nM significantly increased the number of U87 and U251 cells from day 2 of treatment, and proliferation (at day 3) in a similar manner as P4 (10 nM). The treatment with the progesterone receptor (PR) antagonist RU486 (mifepristone), blocked the effects of 5α-DHP on the number of cells and proliferation. Besides, in U251 and LN229 GBM cells, 5α-DHP promoted cell migration (from 12 to 24 h). We also determined that GBM cells expressed the 3α-hydroxysteroid oxidoreductases (3α-HSOR), which reversibly reduce 5α-DHP to allopregnanolone (3α-THP). These data indicate that 5α-DHP induces proliferation and migration of human GBM through the activation of PR.

Molecular genetic analysis of AKR1C2-4 and HSD17B6 genes in subjects 46,XY with hypospadias

BACKGROUND

The formation of the male urethra depends to enzyme-mediated testosterone (T) conversion into 5α-dihydrotestosterone (DHT). Two metabolic pathways could be operating in the fetal testis to synthesize androgens: 1) the "classic" route (T→DHT) mediated by SRD5A2 and 2) a "backdoor" pathway in which DHT is synthesized by aldo-keto reductase family 1, member C2 (AKR1C2), AKR1C3, and AKR1C4 enzymes without formation of a T intermediate.

OBJECTIVE

We studied four genes of the "backdoor" pathway in karyotypic males with hypospadias to ascertain whether gene defects in AKRs impair urethral DHT formation that result in hypospadias.

DESIGN AND PATIENTS

The coding regions of the AKR1C2-4 and HSD17B6 genes were analyzed by PCR-SSCP and sequencing in a cohort of 25 Mexican patients (0.3-9 year-old-children) with 46,XY-hypospadias. Chi-squared tests was performed to evaluate the distribution of genotypes, alleles, and the Hardy-Weinberg (H-W) equilibrium. The effect of the genetic variants was investigated by in silico studies.

RESULTS

Screening studies revealed distinct genotypic patterns at different exons of AKR1C2-4 whereas HSD17B6 presented a wild-type sequence. The DNA analyses detected two synonymous variants (c.327C>T, c.666T>C/unreported) in AKR1C2. The AKR1C3 had two variants (c.15C>G, c.230A>G), two unreported variants (c.538T>C, c.596G>A), and one silent variant (c.312G>A). Two variants (c.434C>G, c.931C>G) were identified in AKR1C4. All variants were in H-W equilibrium without structural changes.

DISCUSSION

Hypospadias have been associated with defects that alter androgen biosynthesis in the human fetal testis, specifically 5α-DHT. We selected four candidate genes involved in the "backdoor" pathway for the formation of 5α-DHT. Molecular assays of the AKR1C2, AKR1C3, and AKR1C4 genes revealed a total of nine genetic single nucleotide variants. Several variants in the AKR1C genes have been associated with a variety of human pathologies. However, our studies suggest that active steroid biosynthesis via AKR1C might not be involved in hypospadias. Additionally, genetic research suggests a low involvement in the "backdoor" 5α-DHT pathway during human sexual development, specifically, the differentiation of male external genitalia.

CONCLUSION

These results indicate that substitutions in AKR1C2-4 are polymorphisms and all genetic variants lacks deleterious significant association with hypospadias. The data suggest that inactivating mutations in the AKR1C2-4 and HSD17B6 genes are an infrequent cause of hypospadias, which might weaken the contribution of the "backdoor" pathway to embryonic urethral masculinization.

Associations between PTSD-Related extinction retention deficits in women and plasma steroids that modulate brain GABAA and NMDA receptor activity

Several studies have demonstrated poor retention of extinction learning among individuals with posttraumatic stress disorder (PTSD). Gonadal hormone signaling in brain appears to influence the retention of extinction learning differently in women with and without PTSD. Women with PTSD, compared to trauma-exposed women without PTSD, show relative deficits in extinction retention during the mid-luteal phase (mLP) of the menstrual cycle, compared to the early follicular phase (eFP). A PTSD-related reduction in conversion of progesterone to its GABAergic metabolites allopregnanolone (Allo) and pregnanolone (PA) may contribute to these findings. The current study in trauma-exposed women with (n = 9) and without (n = 9) PTSD investigated associations between extinction retention and plasma Allo + PA levels, as well as the ratio of Allo + PA to 5α-dihydroprogesterone (5α-DHP), the immediate steroid precursor for Allo. The study also investigated the relationship between extinction retention and the ratio of Allo + PA to dehydroepiandrosterone (DHEA), an adrenally-derived GABA_A receptor antagonist. Study participants completed differential fear-conditioning during both the eFP and mLP of the menstrual cycle. Analyses revealed a strong positive relationship between resting plasma Allo + PA levels and extinction retention during the mLP in the women with, but not without, PTSD (e.g., diagnosis X Allo + PA interaction controlling for early extinction: β = −.0008, p = .003). A similar pattern emerged for the Allo + PA to 5α-DHP ratio (β = -.165, p = .071), consistent with a PTSD-related block in production of Allo and PA at the enzyme 3α-hydroxysteroid dehydrogenase. The ratio of Allo + PA to DHEA appeared to influence extinction retention only during the eFP when Allo + PA and DHEA levels are comparable and thus may compete for effects on GABA_A receptor function. This study aligns with male rodent PTSD models linking experimental reductions in brain Allo levels to deficits in extinction retention and suggests that targeting PTSD-related deficits in GABAergic neurosteroid synthesis may be therapeutic.

Role of human 3α-hydroxysteroid dehydrogenase isoforms (AKR1C1-AKR1C3) in the extrahepatic metabolism of the steroidal aromatase inactivator Formestane

The clinical use of the steroidal aromatase inhibitor Formestane (4-hydroxandrostenedione, 4-OHA) in the treatment of advanced ER+ breast cancer has been discontinued, and therefore, interest in this remarkable drug has vanished. As a C-19 sterol, 4-OHA can undergo extensive intracellular metabolism depending on the expression of specific enzymes in the corresponding cells. We used the metabolites 4β-hydroxyandrosterone, 4β-hydroxyepiandrosterone and its 17β-reduced derivative as standards for the proof of catalytic activity present in the cell culture medium and expressed by the isolated enzymes. All of the aldo-keto reductases AKR1C1, AKR1C2, AKR1C3 and AKR1C4 catalysed the reduction of the 3-keto-group and the Δ^4,5 double bond of 4-OHA at the same time. Molecular docking experiments using microscale thermophoresis and the examination of the kinetic behaviour of the isolated enzymes with the substrate 4-OHA proved that AKR1C3 had the highest affinity for the substrate, whereas AKR1C1 was the most efficient enzyme. Both enzymes (AKR1C1and AKR1C3) are highly expressed in adipose tissue and lungs, exhibiting 3β-HSD activity. The possibility that 4-OHA generates biologically active derivatives such as the androgen 4-hydroxytestosterone or some 17β-hydroxy derivatives of the 5α-reduced metabolites may reawaken interest in Formestane, provided that a suitable method of administration can be developed, avoiding oral or intramuscular depot-injection administration.

Relationships between cerebrospinal fluid GABAergic neurosteroid levels and symptom severity in men with PTSD

Allopregnanolone and pregnanolone (together termed allo + pregnan) are neurosteroid metabolites of progesterone that equipotently facilitate the action of gamma-amino-butyric acid (GABA) at GABA_A receptors. The adrenal steroid dehydroepiandrosterone (DHEA) allosterically antagonizes GABA_A receptors and facilitates N-methyl-D-aspartate (NMDA) receptor function. In prior research, premenopausal women with posttraumatic stress disorder (PTSD) displayed low cerebrospinal fluid (CSF) levels of allo + pregnan [undifferentiated by the gas chromatography-mass spectrometry (GC-MS) method used] that correlated strongly and negatively with PTSD reexperiencing and negative mood symptoms. A PTSD-related decrease in the ratio of allo + pregnan to 5α-dihydroprogesterone (5α-DHP: immediate precursor for allopregnanolone) suggested a block in synthesis of these neurosteroids at 3α-hydroxysteroid dehydrogenase (3α-HSD). In the current study, CSF was collected from unmedicated, tobacco-free men with PTSD (n = 13) and trauma-exposed healthy controls (n = 17) after an overnight fast. Individual CSF steroids were quantified separately by GC-MS. In the men with PTSD, allo + pregnan correlated negatively with Clinician-Administered PTSD Scale (CAPS-IV) total (ρ=-0.74, p = 0.006) and CAPS-IV derived Simms dysphoria cluster (ρ=-0.71, p = 0.01) scores. The allo+pregnan to DHEA ratio also was negatively correlated with total CAPS (ρ=-0.74, p = 0.006) and dysphoria cluster (ρ=-0.79, p = 0.002) scores. A PTSD-related decrease in the 5α-DHP to progesterone ratio indicated a block in allopregnanolone synthesis at 5α-reductase. This study suggests that CSF allo + pregnan levels correlate negatively with PTSD and negative mood symptoms in both men and women, but that the enzyme blocks in synthesis of these neurosteroids may be sex-specific. Consideration of sex, PTSD severity, and function of 5α-reductase and 3α-HSD thus may enable better targeting of neurosteroid-based PTSD treatments.

Wogonin affects proliferation and the energy metabolism of SGC-7901 and A549 cells

Many studies have focused on the identification of therapeutic targets for the treatment of certain types of cancer. Wogonin is a natural flavonoid compound that exhibits a potent anti-cancer effect. The underlying mechanism of wogonin may therefore reveal an effective way to identify novel therapeutic targets. In the current study, growth curves and MTT assays were performed to determine the effects of wogonin in human gastric cancer cells (SGC-7901) and human lung adenocarcinoma cells (A549), respectively. Changes in morphology were observed using hematoxylin and eosin (H&E) staining. The activities of key enzymes in the glycolysis and tricarboxylic acid cycle were measured using spectrophotometry. Western blot analysis was performed to determine the expression levels of hypoxia inducible factor-1α (HIF-1α) and monocarboxylate transporter-4 (MCT-4). Wogonin inhibited cell proliferation in a time- and dose-dependent manner in SGC-7901 and A549 cells. H&E staining suggested that wogonin induced cell morphology changes. In SGC-7901 cells, lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) activities and adenosine triphosphate (ATP) generation were decreased significantly by wogonin treatment compared with the untreated control. In A549 cells, wogonin significantly reduced LDH activity, but exhibited no significant effects on kinase activities or ATP generation. Furthermore, wogonin significantly decreased HIF-1α and MCT-4 protein expression in SGC-7901 cells, but not in A549 cells. The results demonstrated that wogonin inhibited the energy metabolism, cell proliferation and angiogenesis in SGC-7901 and A549 cells by negatively regulating HIF-1α and MCT-4 expression. The differential regulatory roles of wogonin in metabolism-associated enzymes in human gastric cancer and lung adenocarcinoma cells indicated its various antitumor mechanisms. The different metabolic regulatory mechanisms exhibited by wogonin in different tumor tissues should therefore be considered for antitumor therapy.

Intracrine Regulation of Estrogen and Other Sex Steroid Levels in Endometrium and Non-gynecological Tissues; Pathology, Physiology, and Drug Discovery

Our understanding of the intracrine (or local) regulation of estrogen and other steroid synthesis and degradation expanded in the last decades, also thanks to recent technological advances in chromatography mass-spectrometry. Estrogen responsive tissues and organs are not passive receivers of the pool of steroids present in the blood but they can actively modify the intra-tissue steroid concentrations. This allows fine-tuning the exposure of responsive tissues and organs to estrogens and other steroids in order to best respond to the physiological needs of each specific organ. Deviations in such intracrine control can lead to unbalanced steroid hormone exposure and disturbances. Through a systematic bibliographic search on the expression of the intracrine enzymes in various tissues, this review gives an up-to-date view of the intracrine estrogen metabolisms, and to a lesser extent that of progestogens and androgens, in the lower female genital tract, including the physiological control of endometrial functions, receptivity, menopausal status and related pathological conditions. An overview of the intracrine regulation in extra gynecological tissues such as the lungs, gastrointestinal tract, brain, colon and bone is given. Current therapeutic approaches aimed at interfering with these metabolisms and future perspectives are discussed.

Diagnostic value of serum dihydrodiol dehydrogenase 2 levels in patients with non-small-cell lung cancer

OBJECTIVES

Dihydrodiol dehydrogenase 2 (DDH2) plays an important role in pathogenesis of non-small-cell lung cancer (NSCLC). This study aimed to evaluate the value of serum DDH2 levels in NSCLC patients.

METHODS

Serum samples were obtained from 863 NSCLC patients and 439 healthy controls. The samples were randomly divided into a training set and a test set. Serum DDH2 levels were assayed by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The levels of DDH2 in NSCLC patients were significantly higher than those in healthy controls ( P < 0.001). The diagnostic use of DDH2 in lung adenocarcinoma was significantly greater than that of carcinoembryonic antigen, cytokeratin 19 fragment (CYFRA21-1), and carbohydrate antigen 125 ( P < 0.001). Combining DDH2 with carcinoembryonic antigen, CYFRA21-1, and carbohydrate antigen 125 was more effective for lung adenocarcinoma diagnosis than DDH2 alone. In addition, the levels of DDH2 could contribute to the diagnosis of lung squamous cell carcinoma.

CONCLUSIONS

The measurement of serum DDH2 is a valuable diagnostic marker for NSCLC patients.

Intracrine androgen biosynthesis, metabolism and action revisited

Androgens play an important role in metabolic homeostasis and reproductive health in both men and women. Androgen signalling is dependent on androgen receptor activation, mostly by testosterone and 5α-dihydrotestosterone. However, the intracellular or intracrine activation of C19 androgen precursors to active androgens in peripheral target tissues of androgen action is of equal importance. Intracrine androgen synthesis is often not reflected by circulating androgens but rather by androgen metabolites and conjugates. In this review we provide an overview of human C19 steroid biosynthesis including the production of 11-oxygenated androgens, their transport in circulation and uptake into peripheral tissues. We conceptualise the mechanisms of intracrinology and review the intracrine pathways of activation and inactivation in selected human tissues. The contribution of liver and kidney as organs driving androgen inactivation and renal excretion are also highlighted. Finally, the importance of quantifying androgen metabolites and conjugates to assess intracrine androgen production is discussed.

Steroidogenic enzymes, their products and sex steroid receptors during testis development and spermatogenesis in the domestic cat (Felis catus)

In the present study we comprehensively characterize intratesticular sex steroid production, metabolism and receptors in the domestic cat to elucidate the role of testosterone, estradiol and progesterone in testis development, steroid synthesis and spermatogenesis. There is a great demand for new concepts of fertility control in domestic (feral) cats and wild felids. The acquired knowledge will help to understand the regulation of spermatogenesis in felids, and may reveal new target points for male contraception. Progesterone and androgens are produced throughout all stages of testicular development; their synthesizing enzymes are mainly expressed in Leydig cells, and to a much lesser extent also in tubular cells. Aromatase (CYP19A1), the estrogen synthesizing enzyme, is only present in the tubuli and is first detectable in spermatocytes and round spermatids at puberty. As shown by elevated expression of the enzymes steroid 5-α-reductase type 1 (SRD5A) and aldo-keto-reductase family 1 member C3 (AKR1C3), the capacity to metabolize particular steroids increases during testis development. Apparently, this refers to a decreasing intra-testicular testosterone concentration per mg tissue with increasing testis weight during postpuberty. The increasing potential of sulfation of E2 by estrogen sulfotransferase (SULT1E1) with ongoing development might be responsible for the low level of unconjugated intratesticular estradiol in all stages of development probably due to facilitated excretion of conjugated estrogens. For the first time, expression of the progesterone membrane receptor components 1 and 2 (PGRMC1, PGRMC2) was studied in mammalian testis tissue. Both of these and also the progesterone receptor (PGR) are expressed depending on the developmental stage and cell type, suggesting an important regulatory role of progesterone in the testis. Androgen receptor (AR) is present in almost all cell types except for some spermatogenic cells. The co-localization of aromatase with estrogen receptor alpha (ESR1) in spermatocytes and round spermatids of domestic cat testis indicates an auto-/paracrine function of estrogen in spermatogenesis. In summary, the testis of the domestic cat is an important source of sex steroids. All of them could act within the testis but additionally, at least androgens and estrogens are likely secreted by the testis, partly as conjugated steroids.

Overview of the Molecular Steps in Steroidogenesis of the GABAergic Neurosteroids Allopregnanolone and Pregnanolone

Allopregnanolone and pregnanolone-neurosteroids synthesized from progesterone in the brain, adrenal gland, ovary and testis-have been implicated in a range of neuropsychiatric conditions including seizure disorders, post-traumatic stress disorder, major depression, post-partum depression, pre-menstrual dysphoric disorder, chronic pain, Parkinson's disease, Alzheimer's disease, neurotrauma, and stroke. Allopregnanolone and pregnanolone equipotently facilitate the effects of gamma-amino-butyric acid (GABA) at GABAA receptors, and when sulfated, antagonize N-methyl-D-aspartate receptors. They play myriad roles in neurophysiological homeostasis and adaptation to stress while exerting anxiolytic, antidepressant, anti-nociceptive, anticonvulsant, anti-inflammatory, sleep promoting, memory stabilizing, neuroprotective, pro-myelinating, and neurogenic effects. Given that these neurosteroids are synthesized de novo on demand, this review details the molecular steps involved in the biochemical conversion of cholesterol to allopregnanolone and pregnanolone within steroidogenic cells. Although much is known about the early steps in neurosteroidogenesis, less is known about transcriptional, translational, and post-translational processes in allopregnanolone- and pregnanolone-specific synthesis. Further research to elucidate these mechanisms as well as to optimize the timing and dose of interventions aimed at altering the synthesis or levels of these neurosteroids is much needed. This should include the development of novel therapeutics for the many neuropsychiatric conditions to which dysregulation of these neurosteroids contributes.

Risks for animal health related to the presence of zearalenone and its modified forms in feed

Zearalenone (ZEN), a mycotoxin primarily produced by Fusarium fungi, occurs predominantly in cereal grains. The European Commission asked EFSA for a scientific opinion on the risk to animal health related to ZEN and its modified forms in feed. Modified forms of ZEN occurring in feed include phase I metabolites α‐zearalenol (α‐ZEL), β‐zearalenol (β‐ZEL), α‐zearalanol (α‐ZAL), β‐zearalanol (β‐ZAL), zearalanone (ZAN) and phase II conjugates. ZEN has oestrogenic activity and the oestrogenic activity of the modified forms of ZEN differs considerably. For ZEN, the EFSA Panel on Contaminants in the Food Chain (CONTAM) established no observed adverse effect levels (NOAELs) for pig (piglets and gilts), poultry (chicken and fattening turkeys), sheep and fish (extrapolated from carp) and lowest observed effect level (LOAEL) for dogs. No reference points could be established for cattle, ducks, goats, horses, rabbits, mink and cats. For modified forms, no reference points could be established for any animal species and relative potency factors previously established from rodents by the CONTAM Panel in 2016 were used. The dietary exposure was estimated on 17,706 analytical results with high proportions of left‐censored data (ZEN about 60%, ZAN about 70%, others close to 100%). Samples for ZEN were collected between 2001 and 2015 in 25 different European countries, whereas samples for the modified forms were collected mostly between 2013 and 2015 from three Member States. Based on exposure estimates, the risk of adverse health effects of feed containing ZEN was considered extremely low for poultry and low for sheep, dog, pig and fish. The same conclusions also apply to the sum of ZEN and its modified forms.

17beta-hydroxysteroid dehydrogenase type 5 is negatively correlated to apoptosis inhibitor GRP78 and tumor-secreted protein PGK1, and modulates breast cancer cell viability and proliferation

17beta-hydroxysteroid dehydrogenase type 5 (17β-HSD5) is an important enzyme associated with sex steroid metabolism in hormone-dependent cancer. However, reports on its expression and its prognostic value in breast cancer are inconsistent. Here, we demonstrate the impact of 17β-HSD5 expression modulation on the proteome of estrogen receptor-positive (ER+) breast cancer cells. RNA interference technique (siRNA) was used to knock down 17β-HSD5 gene expression in the ER+ breast cancer cell line MCF-7 and the proteome of the 17β-HSD5-knockdown cells was compared to that of MCF-7 cells using two-dimensional (2-D) gel electrophoresis followed by mass spectrometry analysis. Ingenuity pathway analysis (IPA) was additionally used to assess functional enrichment analyses of the proteomic dataset, including protein network and canonical pathways. Our proteomic analysis revealed only four differentially expressed protein spots (fold change > 2, p<0.05) between the two cell lines. The four spots were up-regulated in 17β-HSD5-knockdown MCF-7 cells, and comprised 21 proteins involved in two networks and in functions that include apoptosis inhibition, regulation of cell growth and differentiation, signal transduction and tumor metastasis. Among the proteins are nucleoside diphosphate kinase A (NME1), 78kDa glucose-regulated protein (GRP78) and phosphoglycerate kinase 1 (PGK1). We also showed that expression of 17β-HSD5 and that of the apoptosis inhibitor GRP78 are strongly but negatively correlated. Consistent with their opposite regulation, GRP78 knockdown decreased MCF-7 cell viability whereas 17β-HSD5 knockdown or inhibition increased cell viability and proliferation. Besides, IPA analysis revealed that ubiquitination pathway is significantly affected by 17β-HSD5 knockdown. Furthermore, IPA predicted the proto-oncogene c-Myc as an upstream regulator linked to the tumor-secreted protein PGK1. The latter is over-expressed in invasive ductal breast carcinoma as compared with normal breast tissue and its expression increased following 17β-HSD5 knockdown. Our present results indicate a 17β-HSD5 role in down-regulating breast cancer development. We thus propose that 17β-HSD5 may not be a potent target for breast cancer treatment but its low expression could represent a poor prognosis factor.

Androgen and Estrogen Receptors in Breast Cancer Coregulate Human UDP-Glucuronosyltransferases 2B15 and 2B17

Glucuronidation is an enzymatic process that terminally inactivates steroid hormones, including estrogens and androgens, thereby influencing carcinogenesis in hormone-dependent cancers. While estrogens drive breast carcinogenesis via the estrogen receptor alpha (ERα), androgens play a critical role as prohormones for estrogen biosynthesis and ligands for the androgen receptor (AR). In this study, the expression and regulation of two androgen-inactivating enzymes, the UDP-glucuronosyltransferases UGT2B15 and UGT2B17, was assessed in breast cancer. In large clinical cohorts, high UGT2B15 and UGT2B17 levels positively influenced disease-specific survival in distinct molecular subgroups. Expression of these genes was highest in cases positive for ERα. In cell line models, ERα, AR, and the transcription factor FOXA1 cooperated to increase transcription via tandem binding events at their proximal promoters. ERα activity was dependent on FOXA1, facilitated by AR activation, and potently stimulated by estradiol as well as estrogenic metabolites of 5α-dihydrotestosterone. AR activity was mediated via binding to an estrogen receptor half-site 3' to the FOXA1 and ERα-binding sites. Although AR and FOXA1 bound the UGT promoters in AR-positive/ERα-negative breast cancer cell lines, androgen treatment did not influence basal transcription levels. Ex vivo culture of human breast tissue and ERα+ tumors provided evidence for upregulation of UGT2B15 and UGT2B17 by estrogen or androgen treatment. ERα binding was evident at the promoters of these genes in a small cohort of primary tumors and distant metastases. Collectively, these data provide insight into sex steroid receptor-mediated regulation of androgen-inactivating enzymes in ERα+ breast cancer, which may have subtype-specific consequences for disease progression and outcomes. Cancer Res; 76(19); 5881-93. ©2016 AACR.

New insights into the androgen biotransformation in prostate cancer: A regulatory network among androgen, androgen receptors and UGTs

Androgen, as one kind of steroid hormones, is pivotal in the hormone-sensitive cancer, such as prostate cancer (PCa). The synthesis, elimination, and bioavailability of androgen in prostate cells have been proved to be a main cause of the carcinogenesis, maintenance and deterioration of PCa. This review illustrates the outlines of androgen biotransformation, and further discusses the different enzymes, especially UDP-glucuronyltransferases (UGTs) embedded in both benign and malignant prostate cells, which catalyze the reactions. Although many inhibitors of the enzymes responsible for the synthesis of androgens have been developed into drugs to fight against PCa, the elimination procedures metabolized by the UGTs are less emphasized. Thus the regulatory network among androgen, androgen receptors (AR) and UGTs is carefully reviewed in this article, indicating the determinant effects of UGTs on prostatic androgens and the regulation of AR. Finally, the hypothesis is also put forward that the regulators of UGTs may be developed to accelerate the androgen elimination and benefit PCa therapy.

Combined liquid chromatography-tandem mass spectrometry analysis of progesterone metabolites

Progesterone has a number of important functions throughout the human body. While the roles of progesterone are well known, the possible actions and implications of progesterone metabolites in different tissues remain to be determined. There is a growing body of evidence that these metabolites are not inactive, but can have significant biological effects, as anesthetics, anxiolytics and anticonvulsants. Furthermore, they can facilitate synthesis of myelin components in the peripheral nervous system, have effects on human pregnancy and onset of labour, and have a neuroprotective role. For a better understanding of the functions of progesterone metabolites, improved analytical methods are essential. We have developed a combined liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for detection and quantification of progesterone and 16 progesterone metabolites that has femtomolar sensitivity and good reproducibility in a single chromatographic run. MS/MS analyses were performed in positive mode and under constant electrospray ionization conditions. To increase the sensitivity, all of the transitions were recorded using the Scheduled MRM algorithm. This LC-MS/MS method requires small sample volumes and minimal sample preparation, and there is no need for derivatization. Here, we show the application of this method for evaluation of progesterone metabolism in the HES endometrial cell line. In HES cells, the metabolism of progesterone proceeds mainly to (20S)-20-hydroxy-pregn-4-ene-3-one, (20S)-20-hydroxy-5α-pregnane-3-one and (20S)-5α-pregnane-3α,20-diol. The investigation of possible biological effects of these metabolites on the endometrium is currently undergoing.

Prenatal influence of an androgen agonist and antagonist on the differentiation of the ovine sexually dimorphic nucleus in male and female lamb fetuses

The ovine sexually dimorphic nucleus (oSDN) is 2 times larger in rams than in ewes. Sexual differentiation of the oSDN is produced by testosterone exposure during the critical period occurring between gestational day (GD)60 and GD90 (term, 147 d). We tested the hypothesis that testosterone acts through the androgen receptor to control development of the male-typical oSDN. In experiment 1, pregnant ewes received injections of vehicle, androgen receptor antagonist flutamide, or nonaromatizable androgen dihydrotestosterone (DHT) propionate during the critical period. Fetuses were delivered at GD135. Both antagonist and agonist treatments significantly reduced mean oSDN volume in males but had no effects in females. Experiment 2, we analyzed the effect of treatments on the fetal hypothalamic-pituitary-gonadal axis to determine whether compensatory changes in hormone secretion occurred that could explain the effect of DHT. Pregnant ewes were injected with vehicle, flutamide, or DHT propionate from GD60 to GD84, and fetuses were delivered on GD85. Flutamide significantly increased LH and testosterone in males, whereas DHT significantly decreased both hormones. In females, LH was unaffected by flutamide but significantly reduced by DHT exposure. DHT significantly decreased pituitary gonadotropin and hypothalamic kisspeptin mRNA expression in males and females. These results suggest that androgen receptor mediates the effect of testosterone on oSDN masculinization, because this process was blocked by the androgen receptor antagonist flutamide in eugonadal males. In contrast, the reduction of oSDN volume observed after DHT exposure appears to be mediated by a negative feedback mechanism exerted on the hypothalamus to reduce LH and testosterone secretion. The reduced androgen exposure most likely accounted for the decreased oSDN volume. We conclude that, during the critical period, the male reproductive axis in long gestation species, such as sheep, is sufficiently developed to react to perturbations in serum androgens and mitigate disruptions in brain masculinization.

Important roles of the AKR1C2 and SRD5A1 enzymes in progesterone metabolism in endometrial cancer model cell lines

Endometrial cancer is the most frequently diagnosed gynecological malignancy. It is associated with prolonged exposure to estrogens that is unopposed by progesterone, whereby enhanced metabolism of progesterone may decrease its protective effects, as it can deprive progesterone receptors of their active ligand. Furthermore, the 5α-pregnane metabolites formed can stimulate proliferation and may thus contribute to carcinogenesis. The aims of our study were to: (1) identify and quantify progesterone metabolites formed in the HEC-1A and Ishikawa model cell lines of endometrial cancer; and (2) pinpoint the enzymes involved in progesterone metabolism, and delineate their roles. Progesterone metabolism studies combined with liquid chromatography-tandem mass spectrometry enabled identification and quantification of the metabolites formed in these cells. Further quantitative PCR analysis and small-interfering-RNA-mediated gene silencing identified individual progesterone metabolizing enzymes and their relevant roles. In Ishikawa and HEC-1A cells, progesterone was metabolized mainly to 20α-hydroxy-pregn-4-ene-3-one, 20α-hydroxy-5α-pregnane-3-one, and 5α-pregnane-3α/β,20α-diol. The major difference between these cell lines was rate of progesterone metabolism, which was faster in HEC-1A cells. In the Ishikawa and HEC-1A cells, expression of AKR1C2 was 110-fold and 6800-fold greater, respectively, than expression of AKR1C1, which suggests that 20-ketosteroid reduction of 5α-pregnanes and 4-pregnenes is catalyzed mainly by AKR1C2. AKR1C1/AKR1C2 gene silencing showed decreased progesterone metabolism in both cell lines, thus further supporting the significant role of AKR1C2. SRD5A1 was also expressed in these cells, and its silencing confirmed that 5α-reduction is catalyzed by 5α-reductase type 1. Silencing of SRD5A1 also had the most pronounced effects, with decreased rate of progesterone metabolism, and consequently higher concentrations of unmetabolized progesterone. Our data confirm that in model cell lines of endometrial cancer, AKR1C2 and SRD5A1 have crucial roles in progesterone metabolism, and may represent novel targets for treatment.

Ameliorative effects of Bacillus subtilis ANSB01G on zearalenone toxicosis in pre-pubertal female gilts

The purpose of this research was to investigate the toxicity of zearalenone (ZEA) on the growing performance, genital organs, serum hormones and histopathological changes of pre-pubertal female gilts, and to evaluate the efficacy of Bacillus subtilis ANSB01G in alleviating ZEA toxicosis in gilts. Eighteen pre-pubertal female gilts were randomly allocated to three treatments with one replicate per treatment. The gilts were fed following three diets for 24 days: the Control group was given a basic diet with normal corn; Treatment 1 (T1) was prepared by substituting corn naturally contaminated with ZEA for all normal corn in the basic diet (with a final concentrations of 238.57 μg kg(-1) of ZEA); and Treatment 2 (T2) was prepared by mixing the T1 diet with 2 kg T(-1) of fermented-dried culture of ANSB01G. The results showed that the presence of ZEA in diets significantly increased the vulva size and reproductive organ weight of the T1 gilts as compared with the Control group, and the addition of ANSB01G to diet naturally contaminated with ZEA obviously ameliorated these symptoms, as was observed in the T2 group. The presence of low doses of ZEA in the T1 diet had no significant effect on the level of follicle-stimulating hormone (FSH), luteotrophic hormone (LH) or serum oestradiol (E2) in the serum of gilts, but the prolactin (PRL) level in group T1 increased significantly. The gilts of the T1 group exhibited conspicuous cell enlargement and fatty degeneration of the corpus uteri, swelling, inflammation and lymphocyte infiltration of liver cells as compared with the Control group. The presence of ANSB01G can alleviate these hyperoestrogenic effects caused by ZEA, maintaining the body of gilt in a normal and healthy status. It is suggested that reproductive organs of gilts are seriously affected even if they are fed a low dose of ZEA in less time, and the addition of B. subtilis ANSB01G can effectively alleviate ZEA toxicosis in gilts.

Copy number variation in the horse genome

We constructed a 400K WG tiling oligoarray for the horse and applied it for the discovery of copy number variations (CNVs) in 38 normal horses of 16 diverse breeds, and the Przewalski horse. Probes on the array represented 18,763 autosomal and X-linked genes, and intergenic, sub-telomeric and chrY sequences. We identified 258 CNV regions (CNVRs) across all autosomes, chrX and chrUn, but not in chrY. CNVs comprised 1.3% of the horse genome with chr12 being most enriched. American Miniature horses had the highest and American Quarter Horses the lowest number of CNVs in relation to Thoroughbred reference. The Przewalski horse was similar to native ponies and draft breeds. The majority of CNVRs involved genes, while 20% were located in intergenic regions. Similar to previous studies in horses and other mammals, molecular functions of CNV-associated genes were predominantly in sensory perception, immunity and reproduction. The findings were integrated with previous studies to generate a composite genome-wide dataset of 1476 CNVRs. Of these, 301 CNVRs were shared between studies, while 1174 were novel and require further validation. Integrated data revealed that to date, 41 out of over 400 breeds of the domestic horse have been analyzed for CNVs, of which 11 new breeds were added in this study. Finally, the composite CNV dataset was applied in a pilot study for the discovery of CNVs in 6 horses with XY disorders of sexual development. A homozygous deletion involving AKR1C gene cluster in chr29 in two affected horses was considered possibly causative because of the known role of AKR1C genes in testicular androgen synthesis and sexual development. While the findings improve and integrate the knowledge of CNVs in horses, they also show that for effective discovery of variants of biomedical importance, more breeds and individuals need to be analyzed using comparable methodological approaches.

Genomes of individuals in a species vary in many ways, one of which is DNA copy number variation (CNV). This includes deletions, duplications, and complex rearrangements typically larger than 50 base-pairs. CNVs are part of normal genetic variation contributing to phenotypic diversity but can also be pathogenic and associated with diseases and disorders. In order to distinguish between the two, detailed knowledge about CNVs in the species of interest is needed. Here we studied the genomes of 38 normal horses of 16 diverse breeds, and identified 258 CNV regions. We integrated our findings with previously published horse CNVs and generated a composite dataset of ∼1400 CNVRs. Despite this large number, our analysis shows that CNV research in horses needs further improvement because the current data are based on 10% of horse breeds and that most CNVRs are study-specific and require validation. Finally, we analyzed CNVs in horses with disorders of sexual development and found in two male pseudo-hermaphrodites a large deletion disrupting a group of genes involved in sex hormone metabolism and sexual differentiation. The findings underline the possible role of CNVs in complex disorders such as development and reproduction.

Sex differences in neurosteroid and hormonal responses to metyrapone in posttraumatic stress disorder

RATIONALE

Mechanisms contributing to sex differences in the regulation of acute stress responsivity and their effect on the increased incidence of posttraumatic stress disorder (PTSD) in women are poorly understood. The reproductive hormone, progesterone, through conversion to allopregnanolone (ALLO), suppresses the hypothalamic pituitary adrenal (HPA) axis and has potent anxiolytic effects. The potential that progesterone and allopregnanolone reactivity modulate HPA axis responses and account for sex differences in PTSD has not been previously examined.

OBJECTIVE

The present study examined the effects of sex and PTSD on adrenocorticotropic hormone (ACTH), progesterone, and allopregnanolone responses to metyrapone and whether progesterone and allopregnanolone reactivity could affect the ACTH response in PTSD.

METHODS

Healthy medication-free male and premenopausal follicular phase female participants with chronic PTSD (n = 43; 49 % female) and controls (n = 42; 50 % female) completed an overnight metyrapone challenge and ACTH, progesterone, and allopregnanolone were obtained by repeated blood sampling.

RESULTS

The increase in ACTH response to metyrapone was higher in PTSD subjects compared to controls and in women compared to men. Contrary to our initial prediction of an inverse relationship, progesterone and allopregnanolone were positively associated with ACTH. Progesterone and allopregnanolone partially mediated the relationship between PTSD and ACTH.

CONCLUSIONS

Our findings of increased ACTH to metyrapone in PTSD and in women may reflect heightened hypothalamic CRF hypersecretion. Progesterone and allopregnanolone partially mediated the ACTH response in PTSD. Further characterizing sex differences in these processes will advance our understanding of the pathophysiology of PTSD, and may ultimately lead to better-targeted, more effective treatment.

The transcription factor Ap-1 regulates monkey 20α-hydroxysteroid dehydrogenase promoter activity in CHO cells

Background

Monkey 20α-hydroxysteroid dehydrogenase (20α-HSD) is a catabolic enzyme responsible for converting progesterone into biologically inactive 20α-hydroxyprogesterone, thereby playing a key role in the estrous cycle or pregnancy and allowing ovulation and parturition to occur in most mammalian animals. Monkey 20α-HSD was highly abundant in ovarian and placental tissues during the pre-ovulation and pre-parturition phase and was primarily localized in the syncytiotrophoblast of the placenta. In this study, we focused on the molecular characterization of the monkey 20α-HSD promoter region by conducting reporter assays in Chinese hamster ovary (CHO) K1 cells.

Results

A reporter assay using constructs of various lengths of the 5′-flanking region (-890-Luc, -513-Luc, -306-Luc, -273-Luc, and -70-Luc) revealed that a region corresponding to the activator protein 1 (Ap-1) located between -281 and -274 bp was essential for the transcriptional activity. Absence of the Ap-1 site in -273-Luc dramatically decreased the transcription levels to the control levels. When the reporter constructs were co-transfected with Ap-1 (Jun) and specificity protein (Sp-1) genes, the transcription activities of the constructs increased with the exception of -273 and -70, while that of the double construct was reduced compared to that of Ap-1 alone. Furthermore, mutational analysis demonstrated that a putative Ap-1 site played an important role in the expression of the reporter gene. These findings were confirmed by EMSA examining the interactions of the protein Ap-1 in a nuclear extract from CHO-K1 cells and the expression levels of the Ap-1 transcription factor in pre-parturition placenta and CHO-K1 cells. Although mut-1 and mut-2 of Ap-1 bound with nuclear extracts from CHO-K1 cells, the transcriptional activity of mut-3 was almost completely suppressed.

Conclusions

Our results indicate that the Ap-1 site (-281 → -274) (5′-TGTCTCAT-3′) plays a crucial role in the activation of the monkey 20α-HSD gene. Thus, we demonstrated that monkey 20α-HSD promoter activity is regulated by the transcription factor Ap-1 in CHO-K1 cells.

Fine mapping analysis confirms and strengthens linkage of four chromosomal regions in familial hypospadias

Hypospadias is a common male genital malformation and is regarded as a complex disease affected by multiple genetic as well as environmental factors. In a previous genome-wide scan for familial hypospadias, we reported suggestive linkage in nine chromosomal regions. We have extended this analysis by including new families and additional markers using non-parametric linkage. The fine mapping analysis displayed an increased LOD score on chromosome 8q24.1 and 10p15 in altogether 82 families. On chromosome 10p15, with the highest LOD score, we further studied AKR1C2, AKR1C3 and AKR1C4 involved in steroid metabolism, as well as KLF6 expressed in preputial tissue from hypospadias patients. Mutation analysis of the AKR1C3 gene showed a new mutation, c.643G>A (p.(Ala215Thr)), in a boy with penile hypospadias. This mutation is predicted to have an impact on protein function and structure and was not found in controls. Altogether, we homed in on four chromosomal regions likely to harbor genes for hypospadias. Future studies will aim for studying regulatory sequence variants in these regions.

Gene expression and localization of 20α-hydroxysteroid dehydrogenase (HSD) in reproductive tissues during early pregnancy of cattle

The enzyme 20α-hydroxysteroid dehydrogenase (20α-HSD) catalyzes the conversion of progesterone to its inactive form, 20α-hydroxyprogesterone, and this enzyme has an important role in the regulation of luteal function in mammals. It has previously been determined that the 20α-HSD gene is primarily expressed by large luteal cells during the late stage of the estrous cycle. In the present study, the amounts of mRNA were determined in cultured cells of the corpus luteum (CL) cells. The localization of 20α-HSD was also determined in ovaries, placenta, and endometrium during early pregnancy. The amount of 20α-HSD mRNA in cultured luteal cells increased with time and by treatment with the luteolysis agent prostaglandin F2α (PGF2α). Immunofluorescence assays detected increased protein in cultured luteal cells. The 20α-HSD mRNA and protein were present in the ovaries, placenta, and endometrium on Days 30, 60, and 90 of pregnancy. In particular, gene expression was much greater in the ovary than in the placenta and endometrium. Immuno-histochemical analysis indicated that bovine 20α-HSD was primarily localized in ovarian large luteal cells, placental cytotrophoblast villus, and glandular epithelial cells of the endometrium during early pregnancy. Furthermore, in situ analyses demonstrated colocalization of 20α-HSD mRNA and protein. Taken together, results of the present study indicate that 20α-HSD mRNA and protein are co-localized in large luteal cells, the placenta, and the endometrium during early pregnancy, suggesting that 20α-HSD regulates mechanisms involved in the maintenance of early pregnancy.

Steroidogenic enzyme AKR1C3 is a novel androgen receptor-selective coactivator that promotes prostate cancer growth

PURPOSE

Castration-resistant prostate cancer (CRPC) may occur by several mechanisms including the upregulation of androgen receptor (AR), coactivators, and steroidogenic enzymes, including aldo keto reductase 1C3 (AKR1C3). AKR1C3 converts weaker 17-keto androgenic precursors to more potent 17-hydroxy androgens and is consistently the major upregulated gene in CRPC. The studies in the manuscript were undertaken to examine the role of AKR1C3 in AR function and CRPC.

EXPERIMENTAL DESIGN

LNCaP cells stably transfected with AKR1C3 and VCaP cells endogenously expressing AKR1C3 were used to understand the effect of AKR1C3 on prostate cancer cell and tumor growth in nude mice. Chromatin immunoprecipitation, confocal microscopy, and co-immunoprecipitation studies were used to understand the recruitment of AKR1C3, intracellular localization of AKR1C3 and its interaction with AR in cells, tumor xenograft, and in Gleason sum 7 CRPC tissues. Cells were transiently transfected for AR transactivation. Novel small-molecule AKR1C3-selective inhibitors were synthesized and characterized in androgen-dependent prostate cancer and CRPC models.

RESULTS

We identified unique AR-selective coactivator- and prostate cancer growth-promoting roles for AKR1C3. AKR1C3 overexpression promotes the growth of both androgen-dependent prostate cancer and CRPC xenografts, with concomitant reactivation of androgen signaling. AKR1C3 interacted with AR in prostate cancer cells, xenografts, and in human CRPC samples and was recruited to the promoter of an androgen-responsive gene. The coactivator and growth-promoting functions of AKR1C3 were inhibited by an AKR1C3-selective competitive inhibitor.

CONCLUSIONS

AKR1C3 is a novel AR-selective enzymatic coactivator and may represent the first of more than 200 known nuclear hormone receptor coactivators that can be pharmacologically targeted.

Of marsupials and men: "Backdoor" dihydrotestosterone synthesis in male sexual differentiation

Following development of the fetal bipotential gonad into a testis, male genital differentiation requires testicular androgens. Fetal Leydig cells produce testosterone that is converted to dihydrotestosterone in genital skin, resulting in labio-scrotal fusion. An alternative 'backdoor' pathway of dihydrotestosterone synthesis that bypasses testosterone has been described in marsupials, but its relevance to human biology has been uncertain. The classic and backdoor pathways share many enzymes, but a 3α-reductase, AKR1C2, is unique to the backdoor pathway. Human AKR1C2 mutations cause disordered sexual differentiation, lending weight to the idea that both pathways are required for normal human male genital development. These observations indicate that fetal dihydrotestosterone acts both as a hormone and as a paracrine factor, substantially revising the classic paradigm for fetal male sexual development.

Quantitative evaluation of aldo-keto reductase expression in hepatocellular carcinoma (HCC) cell lines

The involvement of aldo–keto reductases (AKRs) in tumorigenesis is widely reported, but their roles in the pathological process are not generally recognized due to inconsistent measurements of their expression. To overcome this problem, we simultaneously employed real-time PCR to examine gene expression and multiple reaction monitoring (MRM) of mass spectrometry (MS) to examine the protein expression of AKRs in five different hepatic cell lines. These include one relatively normal hepatic cell line, L-02, and four hepatocellular carcinoma (HCC) cell lines, HepG2, HuH7, BEL7402 and SMMC7721. The results of real-time PCR showed that expression of genes encoding the AKR1C family members rather than AKR1A and AKR1B was associated with tumor, and most of genes encoding AKRs were highly expressed in HuH7. Similar observations were obtained through MRM. Different from HuH7, the protein abundance of AKR1A and AKR1B was relatively consistent among the other four hepatic cell lines, while protein expression of AKR1C varied significantly compared to L-02. Therefore, we conclude that the abundant distribution of AKR1C proteins is likely to be associated with liver tumorigenesis, and the AKR expression status in HuH7 is completely different from other liver cancer cell lines. This study, for the first time, provided both overall and quantitative information regarding the expression of AKRs at both mRNA and protein levels in hepatic cell lines. Our observations put the previous use of AKRs as a biomarker into question since it is only consistent with our data from HuH7. Furthermore, the data presented herein demonstrated that quantitative evaluation and comparisons within a protein family at both mRNA and protein levels were feasible using current techniques.

Polymorphisms in AKR1C4 and HSD3B2 and differences in serum DHEAS and progesterone are associated with paranoid ideation during mania or hypomania in bipolar disorder

Paranoia is commonly a mood-incongruent psychotic symptom of mania which may be related to dopamine dysregulation. Progesterone and its metabolite allopregnanolone (ALLO) have been found in animals to antagonize the effects of dopamine. We therefore examined serum progesterone, its endogenous antagonist DHEAS and polymorphisms of the genes coding for certain steroidogenetic enzymes (AKR1C4, HSD3B2, and SRD5A1) in 64 males and 96 females with bipolar 1 or 2 disorder with or without paranoid ideation during mood elevation. Euthymic morning serum progesterone, DHEAS and cortisol concentrations were measured in males and in premenopausal women who were in follicular phase and not taking oral contraceptives. In women only, SNPs in AKR1C4 reduced the likelihood of having exhibited paranoid ideation by circa 60%. The haplotype of all 4 SNPs in the AKR1C4 gene reduced the risk of exhibiting paranoia by 80% (OR 0.19, 95% CI 0.06-0.61, p=0.05). A history of paranoid ideation was not, however, related to progesterone or DHEAS concentration. Serum DHEAS and progesterone concentrations were lower in men who had shown paranoid ideation during mania/hypomania compared with those who had not (F=7.30, p=0.006) however this was not coupled to polymorphisms in the selected genes. The ancestral G in rs4659174 in HSD3B2 was in men associated with a lower risk of paranoid ideation (likelihood ratio χ(2) 3.97, p=0.046, OR 0.31 (95% CI 0.10-0.96)) but did not correlate with hormone concentrations. Hence, gene variants in the steroidogenetic pathway and steroids concentration differences may be involved in the susceptibility to paranoia during mood elevation.

Contributions of human enzymes in carcinogen metabolism

Considerable support exists for the roles of metabolism in modulating the carcinogenic properties of chemicals. In particular, many of these compounds are pro-carcinogens that require activation to electrophilic forms to exert genotoxic effects. We systematically analyzed the existing literature on the metabolism of carcinogens by human enzymes, which has been developed largely in the past 25 years. The metabolism and especially bioactivation of carcinogens are dominated by cytochrome P450 enzymes (66% of bioactivations). Within this group, six P450s--1A1, 1A2, 1B1, 2A6, 2E1, and 3A4--accounted for 77% of the P450 activation reactions. The roles of these P450s can be compared with those estimated for drug metabolism and should be considered in issues involving enzyme induction, chemoprevention, molecular epidemiology, interindividual variations, and risk assessment.

Transactivation activity of human papillomavirus type 16 E6*I on aldo-keto reductase genes enhances chemoresistance in cervical cancer cells

The oncogenic E6 proteins produced by high-risk human papillomaviruses (HPVs) are invariably expressed in cervical carcinomas and are multifunctional proteins capable of affecting host-cell proliferation by binding and deregulating key host molecules such as p53. High-risk HPVs, including HPV16, have the unique ability to splice the E6 viral transcript, resulting in the production of a truncated E6 protein known as E6*I whose precise biological function is unclear. This study explored the changes in gene expression of the cervical cancer C33A cell line stably expressing HPV16 E6*I (16E6*I) and observed the upregulation of ten genes. Two of these genes were aldo-keto reductases (AKR1Cs), AKR1C1 and AKR1C3, which have been implicated in drug resistance. The results demonstrated that expression of 16E6*I, but not full-length E6, specifically increased AKR1C1 transcript levels although it did not alter AKR1C2 transcript levels. HPV16 E7 alone also had the ability to cause a moderate increase in AKR1C3 at both mRNA and protein levels. Site-directed mutagenesis of 16E6*I revealed that transactivation activity was abolished in R8A, R10A and T17A 16E6*I mutants without altering their intracellular localization patterns. Loss of transactivation activity of the 16E6*I mutants resulted in a significant loss of AKR1C expression and a decrease in drug resistance. Analysis of the AKR1C1 promoter revealed that, unlike the E6 protein, 16E6*I does not mediate transactivation activity solely through Sp1-binding sites. Taken together, it was concluded that 16E6*I has a novel function in upregulating expression of AKR1C and, in concert with E7, has implications for drug treatment in HPV-mediated cervical cancer.