Adrenal Androgen Biosynthesis Research Articles

MicroRNA regulation of adrenal glucocorticoid and androgen biosynthesis.

Steroid hormones are derived from a common precursor molecule, cholesterol, and regulate a wide range of physiologic function including reproduction, salt balance, maintenance of secondary sexual characteristics, response to stress, neuronal function, and various metabolic processes. Among the steroids synthesized by the adrenal and gonadal tissues, adrenal mineralocorticoids, and glucocorticoids are essential for life. The process of steroidogenesis is regulated at multiple levels largely by transcriptional, posttranscriptional, translational, and posttranslational regulation of the steroidogenic enzymes (i.e., cytochrome P450s and hydroxysteroid dehydrogenases), cellular compartmentalization of the steroidogenic enzymes, and cholesterol processing and transport proteins. In recent years, small noncoding RNAs, termed microRNAs (miRNAs) have been recognized as major post-transcriptional regulators of gene expression with essential roles in numerous biological processes and disease pathologies. Although their role in the regulation of steroidogenesis is still emerging, several recent studies have contributed significantly to our understanding of the role miRNAs play in the regulation of the steroidogenic process. This chapter focuses on the recent developments in miRNA regulation of adrenal glucocorticoid and androgen production in humans and rodents.

FRI371 Serum Androstenedione As An Additive Biomarker In Ectopic Cushing’s Syndrome Evaluation

Abstract Disclosure: S. Zhang: None. J.C. Lo: None. M.G. Jaffe: None. H. Arzumanyan: None. Background: Ectopic Cushing’s syndrome (ECS) results from glucocorticoid excess secondary to ectopic ACTH or CRH producing tumors. Although ECS identification can be challenging when presentation lacks classic Cushing’s features, ectopic ACTH secretion can result in a key constellation of findings that facilitate early clinical recognition. We describe a case of ECS from an ACTH-producing carcinoid tumor of the lung presenting with resistant hypertension, severe hypokalemia, and muscle weakness. In addition to significant hypercortisolism, laboratory findings were notable for high androstenedione levels without concomitant increase in DHEAS and testosterone levels. Case: A 59-year-old female athlete with history of well-controlled hypertension developed difficult to control hypertension, requiring escalation to triple antihypertensive therapy within 3 months. During this time, she had multiple emergency department visits for progressive muscle weakness, hypertension, and persistent hypokalemia despite potassium supplementation. She was hospitalized for further evaluation. Physical examination was notable for bruising, muscle wasting, thin extremities, facial fullness, and disproportionate abdominal adiposity. Workup for Cushing’s syndrome demonstrated ACTH-dependent hypercortisolism and markedly elevated androstenedione 398 ng/dL (normal 20-75 ng/dL) despite normal DHEAS 48 mcg/dL (normal <430 mcg/dL) and total testosterone 11 ng/dL (normal <45 ng/dL) levels. A chest CT identified a 3.8 cm right lower lobe lung mass and transbronchial biopsy confirmed atypical carcinoid tumor. She underwent a right middle and lower lobe bilobectomy with complete tumor resection. Cortisol, androstenedione, and potassium levels rapidly normalized postoperatively, and blood pressure returned to baseline, well-controlled on monotherapy. The patient only required 3 days of hydrocortisone therapy for transient steroid withdrawal symptoms. Conclusions: Our case illustrates a difficult to diagnose uncommon disease presenting with resistant hypertension, hypokalemia and marked androstenedione elevation despite normal DHEAS and testosterone levels. This steroidogenic profile has been reported in other ECS cases and attributed to differential effects of ectopic ACTH production on adrenal androgen biosynthesis (1). Although ECS is rare and the primary lesion can be difficult to identify, disproportionate elevation in androstenedione may prompt recognition of ECS and support early detection and management. Reference: (1) Barbetta L, Dall’Asta C, Re T, Colombo P, Travaglini P, Ambrosi B. Androgen secretion in ectopic ACTH syndrome and in Cushing’s disease: modifications before and after surgery. Horm Metab Res Horm Stoffwechselforschung Horm Metab. 2001;33(10):596-601 Presentation: Friday, June 16, 2023

The role of gonadotropins in testicular and adrenal androgen biosynthesis pathways-Insights from males with congenital hypogonadotropic hypogonadism on hCG/rFSH and on testosterone replacement.

To delineate the role of gonadotropins in male androgen biosynthesis pathways. Case-control study. Twenty five males with congenital hypogonadotropic hypogonadism (CHH) underwent hCG/rFSH and testosterone treatment sequentially. Serum steroid hormone profiles (testosterone precursors and metabolites) on both replacement regimens were analysed, using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and compared to those of healthy controls, matched by age, BMI and serum testosterone. On testosterone replacement, serum concentrations of the classic Δ4 pathway hormones progesterone and 17-hydroxy-progesterone (17-OHP), and the marker steroid of an alternative pathway of testosterone synthesis (androstenediol) were decreased, compared to controls. Androstanediol, a marker of the backdoor pathway of dihydrotestosterone (DHT) synthesis, was increased. 17-OH-pregnenolone, androstenedione and DHEAS (Δ5 pathway), three 11-oxygenated C19 androgens (11-keto-A4, 11-keto-T and 11-keto-DHT) and the testosterone (T) metabolites DHT and 17ß-oestradiol (E2) were similar to controls. On gonadotropin replacement, 17-OHP, 17-OH-pregnenolone, DHEAS and androstenedione, as well as DHT, androstenediol, and all 11-oxygenated C19 androgens were normal. Progesterone (Δ4 pathway) was slightly decreased, and androstanediol (backdoor DHT pathway) and E2 (T metabolite) were increased. In males with CHH, serum steroid hormone profiles resemble those of healthy men, if hCG/rFSH is used for substitution. Gonadotropins contribute to steroid hormone production along the classic Δ4 pathway and co-activate an alternative pathway of testosterone biosynthesis via androstenediol. Backdoor DHT biosynthesis, Δ5 17-OH-pregnenolone, DHEA(S) and androstenedione synthesis and 11-oxygenated C19 androgen production are activated independently of gonadotropins. The androgen replacement modality used for treatment of hypogonadal males with absent or reduced endogenous LH/FSH secretion may impact on long-term health and quality of life.

MON-209 Systemic and Hypothalamic Hyperandrogenism Emerges Following Elimination of Ovarian and Extra-Ovarian Sources of Estradiol in Female Marmoset Monkeys

In female nonhuman primates, ovarian and extra-ovarian estradiol (E2) contribute components of negative and positive feedback regulation of pituitary gonadotropin, as well as sexually receptive behavior. Little is known, however, about accompanying changes in brain steroid hormone content, particularly at the level of the hypothalamus. As part of a larger study investigating ovarian and extra-ovarian E2 regulation of reproductive, sexual and metabolic function, 13 adult female marmosets housed with well-established male pairmates were ovariectomized (OVX) and immediately assigned to one of three treatment groups: E2 SC capsule replacement (E2, n=5, mimicking peri-ovulatory circulating E2 levels), vehicle (VEH, n=4, daily PO 1ml/kg Ensure®), and aromatase inhibition (LET, n=4, daily PO 1mg/kg letrozole). At necropsy 8-9 months following treatment onset, plasma samples were obtained and hemi-hypothalami were harvested. Tissues and samples were placed in liquid nitrogen and frozen at -80C until assayed by LC-MS/MS (steroid hormones) or RIA (gonadotropin). LET females exhibited elevated (p=0.05) post-OVX circulating CG levels (marmoset LH equivalent) compared to E2 females. Circulating E2 levels were similarly diminished (p=0.01) in VEH and LET female groups compared to E2 females, while circulating levels of DHEA were comparably elevated (p<0.001) in VEH and LET compared to E2 females. Increased DHEA likely reflects absence of E2-inhibition of adrenal androgen biosynthesis and development of a zona reticularis. Circulating levels of testosterone (T), androstenedione (A4), progesterone (P4) and 17-hydroxyP4 (17OHP) were comparable between all three female groups. Changes in hypothalamic steroids, however, differed from circulating levels. Hypothalamic E2 was diminished (p<0.001) only in LET compared to E2 and VEH females. In contrast, hypothalamic A4 was increased in both VEH (p=0.03) and LET (p=0.05) compared to E2 females, while hypothalamic DHEA was increased (p=0.04) only in VEH compared to E2 and LET females. Hypothalamic T, P4 and 17OHP were comparable across treatment groups, not surprisingly producing a diminished (p<0.001) E2:T ratio in LET versus E2 females. Taken together, these results suggest E2 inhibition of adrenal and hypothalamic androgen biosynthesis and reveal potential contribution of hypothalamic E2 and androgens to physiological and behavioral function, translationally relevant when E2 production or action is impaired, such as in women with polycystic ovary syndrome.

Targeting of CYP17A1 Lyase by VT-464 Inhibits Adrenal and Intratumoral Androgen Biosynthesis and Tumor Growth of Castration Resistant Prostate Cancer.

Cytochrome P450 17α-hydroxylase/17,20-lyase (CYP17A1) is a validated treatment target for the treatment of metastatic castration-resistant prostate cancer (CRPC). Abiraterone acetate (AA) inhibits both 17α-hydroxylase (hydroxylase) and 17,20-lyase (lyase) reactions catalyzed by CYP17A1 and thus depletes androgen biosynthesis. However, coadministration of prednisone is required to suppress the mineralocorticoid excess and cortisol depletion that result from hydroxylase inhibition. VT-464, a nonsteroidal small molecule, selectively inhibits CYP17A1 lyase and therefore does not require prednisone supplementation. Administration of VT-464 in a metastatic CRPC patient presenting with high tumoral expression of both androgen receptor (AR) and CYP17A1, showed significant reduction in the level of both dehydroepiandrosterone (DHEA) and serum PSA. Treatment of a CRPC patient-derived xenograft, MDA-PCa-133 expressing H874Y AR mutant with VT-464, reduced the increase in tumor volume in castrate male mice more than twice as much as the vehicle (P < 0.05). Mass spectrometry analysis of post-treatment xenograft tumor tissues showed that VT-464 significantly decreased intratumoral androgens but not cortisol. VT-464 also reduced AR signaling more effectively than abiraterone in cultured PCa cells expressing T877A AR mutant. Collectively, this study suggests that VT-464 therapy can effectively treat CRPC and be used in precision medicine based on androgen receptor mutation status.

Specificity of anti-prostate cancer CYP17A1 inhibitors on androgen biosynthesis

The orteronel, abiraterone and galeterone, which were developed to treat castration resistant prostate cancer, inhibit 17,20 lyase activity but little is known about their effects on adrenal androgen biosynthesis. We studied the effect of several inhibitors and found that orteronel was selective towards 17,20 lyase activity than abiraterone and galeterone. Gene expression analysis showed that galeterone altered the expression of HSD3B2 but orteronel did not change the expression of HSD3B2, CYP17A1 and AKR1C3. The CYP19A1 activity was not inhibited except by compound IV which lowered activity by 23%. Surprisingly abiraterone caused complete blockade of CYP21A2 activity. Analysis of steroid metabolome by gas chromatography – mass spectrometry revealed changes in steroid levels caused by different inhibitors. We can conclude that orteronel is a highly specific inhibitor of 17,20 lyase activity. The discovery of these specific drug actions on steroidogenic enzyme activities would be valuable for understanding the regulation of androgens.

Effect of CYP17A1 17,20 Lyase Inhibitors on Regulation of Adrenal Androgen Biosynthesis

BackgroundThe P450c17 (CYP17A1) plays a vital role in regulating adrenal androgen production. CYP17A1 localized in the endoplasmic reticulum can catalyze both 17α‐hydroxylase and 17,20 lyase reactions. Understanding the mechanisms regulating 17,20 lyase activity is important for the understanding of hyperandrogenic disorders such as premature, exaggerated adrenarche and the polycystic ovary syndrome, and also for the design of selective 17,20 lyase inhibitors for use in hyperandrogenic states and in sex‐steroid dependent cancers. The orteronel and galeterone are known to inhibit 17,20 lyase activity; however, the precise mechanism of the CYP17A1 inhibition remains unknown. These inhibitors have been developed to treat the castration resistant prostate cancer (CRPC) but little is known about their effect on adrenal androgen biosynthesis. We have studied the specific 17,20 layse inhibitors to understand their effects on CYP17A1 and adrenal androgen biosynthesis.MethodsWe used NCI‐H295R adenocarcinoma cells to study the effect of orteronel and galeterone. We treated the H295R cells with 0–2μM orteronel and galeterone for 24 hours. Steroid production was labeled with [3H] pregnenolone for 90 min. Steroids were extracted and resolved by thin layer chromatography. For specific analysis of the CYP17A1, CYP19A1 and CYP21A2 activities, cells were treated with 1μM trilostane (a specific blocker of HSD3B) for 90 min before adding radiolabelled steroids. To study the effect of these inhibitors on steroidogenic gene expression we performed the relative quantification PCR (qRT‐PCR). Steroid metabolome of cells was determined in parallel experiments using GC‐MC/LC‐MS.ResultsThe drugs orteronel and galeterone were able to inhibit CYP17A1 activity in H295R cells. Both drugs have more potency towards the 17,20 lyase activity but we also observed that they partially affected 17 alpha‐hydroxylase activity. From our results, we observed the orteronel seems to be more potent and selective towards 17,20 lyase activity than galeterone. However, we also found dihydroepiandrosterone (DHEA), cortisol and androstenedione were drastically decreased by both compounds at 1 and 2μm concentration. Further, we also studied effect of these inhibitors on genes which are involved in androgen biosynthesis. We found slight increase in the HSD3B2 gene expression under galeterone treatment but no change was observed in CYP17A1 and AKR1C3 expression.ConclusionsBased on our results we conclude that orteronel is a more potent inhibitor of 17,20 lyase activity and also has partial effect on 17α‐hydroxylase activities.Support or Funding InformationThis work was supported by grants to Amit V Pandey from the Swiss National Science Foundation and Bern University Research Foundation.

Regulation of human (adrenal) androgen biosynthesis—New insights from novel throughput technology studies

Androgens are precursors for sex steroids and are predominantly produced in the human gonads and the adrenal cortex. They are important for intrauterine and postnatal sexual development and human reproduction. Although human androgen biosynthesis has been extensively studied in the past, exact mechanisms underlying the regulation of androgen production in health and disease remain vague. Here, the knowledge on human androgen biosynthesis and regulation is reviewed with a special focus on human adrenal androgen production and the hyperandrogenic disorder of polycystic ovary syndrome (PCOS). Since human androgen regulation is highly specific without a good animal model, most studies are performed on patients harboring inborn errors of androgen biosynthesis, on human biomaterials and human (tumor) cell models. In the past, most studies used a candidate gene approach while newer studies use high throughput technologies to identify novel regulators of androgen biosynthesis. Using genome wide association studies on cohorts of patients, novel PCOS candidate genes have been recently described. Variant 2 of the DENND1A gene was found overexpressed in PCOS theca cells and confirmed to enhance androgen production. Transcriptome profiling of dissected adrenal zones established a role for BMP4 in androgen synthesis. Similarly, transcriptome analysis of human adrenal NCI-H295 cells identified novel regulators of androgen production. Kinase p38α (MAPK14) was found to phosphorylate CYP17 for enhanced 17,20 lyase activity and RARB and ANGPTL1 were detected in novel networks regulating androgens. The discovery of novel players for androgen biosynthesis is of clinical significance as it provides targets for diagnostic and therapeutic use.

Predicting response to abiraterone acetate (AA): mRNA biomarker analysis of study COU-AA-302.

5058 Background: AA is metabolized to abiraterone, a CYP17 inhibitor that blocks testicular, adrenal, and tumoral androgen biosynthesis. AA is approved for the treatment of metastatic castration-re...

Highly-selective 4-(1,2,3-triazole)-based P450c17a 17,20-lyase inhibitors

The orally-active CYP17A1 inhibitor abiraterone acetate (AA) decreases adrenal and intratumoral androgen biosynthesis and is an effective agent for the treatment of prostate cancer. Abiraterone potently inhibits both reactions catalyzed by CYP17, the 17α-hydroxylase (hydroxylase) reaction as well as the 17,20-lyase (lyase) transformation. CYP17 hydroxylase inhibition prevents the synthesis of adrenal glucocorticoids and causes an accumulation of circulating mineralocorticoids. As a consequence of potent CYP17 hydroxylase inhibition (i.e., lack of lyase selectivity), AA must be co-administered with the cortisol replacement prednisone and patients may experience the effects of mineralocorticoid excess syndrome (MES). Herein, we describe rationally-designed, CYP17 lyase-selective inhibitors that could prove safer and more effective than abiraterone. Using proprietary methodology, the high-affinity pyridine or imidazole metal-binding group found in current clinical CYP17 inhibitors was replaced with novel, less avid, metal-binding groups in concert with potency-enhancing molecular scaffold modifications. This process produced a unique series of CYP17 lyase-selective inhibitors that included the oral agent 6 (VT-464), now in Phase 2 prostate cancer clinical trials. The chemical methodology described is potentially applicable to the design of new and more effective metalloenzyme inhibitor treatments for a broad array of diseases.

Abstract A194: A QT/QTc and multi-dose pharmacokinetic (PK) study of abiraterone acetate (AA) plus prednisone (P) in patients (pts) with metastatic castration-resistant prostate cancer (mCRPC).

Abstract Background: AA is the prodrug of abiraterone (A), an androgen biosynthesis inhibitor that selectively inhibits CYP17, thereby blocking testicular, adrenal, and prostatic intratumoral androgen biosynthesis. In a phase 3 study, AA+P demonstrated survival improvements in post-docetaxel mCRPC pts (De Bono ESMO 2010). ADT with an LHRH analog (LHRHa) has been associated with median QTc interval prolongation of 9–21 msec (Garnick ASCO 2004). Primary objective: effects of AA+P on QT/QTc interval duration in mCRPC pts receiving LHRHa. Secondary objectives: pharmacokinetics (PK) of AA and abiraterone (A) after single/multiple doses of AA. Methods: In this open-label, single-arm phase 1b study (COU-AA-006/NCT00910754), 33 mCRPC pts with disease progression after failure of GnRH hormone therapy, a PSA ≥2 ng/mL and ≤1 course of prior chemotherapy, received AA 1000mg orally QD + P 5mg orally BID. ECGs were collected in triplicate using 12-lead Holter monitoring. Baseline ECGs were obtained on Cycle (C)1 Day (D)-1. Serial ECG recordings and time-matched PK blood samples were collected over 24 hrs on C1D1 and C2D1. Serial PK blood samples were also collected over 24 hrs on C1D8. Results: After AA administration, the upper bound of the 2-sided 90% CI for the mean baseline-adjusted QTcF change was &amp;lt;10 msec; no subjects discontinued due to QTc prolongation or AEs. Most AA plasma concentrations were below the quantification limit; thus AA PK analysis was not performed. A linear mixed-effects model showed no apparent relationship between change in QTcF and A plasma concentrations (estimated slope [90%CI): 0.0031 [−0.0040, 0.0102]). Exposure to A after multiple AA dosing on C1D8 and C2D1 increased versus exposure after single dose on C1D1; accumulation ratios for C1D8 (1.8–2.0) and C2D1 (2.0–2.2) were similar. The most commonly reported treatment-emergent AE (TEAE) was dizziness (12%); all TEAEs were grade 1; except 1 grade 3 AE (increased ALP) with no grade 4 TEAEs. Conclusions: There is no significant effect of AA+P on the cardiac QT/QTc interval in mCRPC pts. No relationship between change in QTcF and A plasma concentration was observed. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A194.

Abiraterone acetate for prostate cancer: a new era of hormonal therapies

Abiraterone acetate for prostate cancer: a new era of hormonal therapies

Blockade of testicular and adrenal androgens in prostate cancer treatment

Prostate cancer is the most hormone sensitive of all cancers. However, any hormonal therapeutic strategy must take into account the fact that two almost equivalent sources of androgens act in the prostate, namely testosterone of testicular origin, and the locally produced androgens testosterone and dihydrotestosterone (DHT) derived from dehydroepiandrosterone of adrenal origin. Combined androgen blockade--medical or surgical castration plus a pure antiandrogen--would, therefore, be the logical first-line treatment for prostate cancer, although castration or an antiandrogen alone is still chosen in the majority of cases. Although long-term control, or even cure, is possible when combined androgen blockade is used when the tumor is localized, resistance to treatment invariably develops in patients when start of treatment is delayed until the disease has become metastatic. This observation can be explained either by elevated levels of the androgen receptor, which can increase the response to low levels of androgens and also modify the response to antiandrogens; or by local biosynthesis of androgens. Research to identify new and more potent antiandrogens, as well as blockers of peripheral and adrenal androgen biosynthesis--such as abiraterone--could be of great importance.

Impact of Differential P450c17 Phosphorylation by cAMP Stimulation and by Starvation Conditions on Enzyme Activities and Androgen Production in NCI-H295R Cells

CYP17A1 plays a pivotal role in the biosynthesis of androgens in the adrenals and the gonads. Although this enzyme catalyzes two different reactions on one single active site, its specific activities are regulated independently. Although the 17alpha-hydroxylase activity is rather constant and regulated by gene expression, the 17,20-lyase activity varies significantly with the amount of cofactors or by protein phosphorylation. cAMP increases CYP17A1 expression, P450c17 phosphorylation, and androgen production. However, the exact mechanism(s) and the specific regulators of CYP17A1 remain unknown. Therefore, we studied the regulation of adrenal androgen biosynthesis in human adrenal H295R cells focusing on CYP17A1. We analyzed androgen production and P450c17 activities in H295R cells grown under normal and serum-free conditions and/or after stimulation with 8-bromoadenosine-cAMP. H295R cells grown in starvation medium produced more androgens and had decreased HSD3B2 expression and activity but increased P450c17-17,20-lyase activity and serine phosphorylation. Although starvation increased serine phosphorylation of P450c17 specifically, cAMP stimulation enhanced threonine phosphorylation exclusively. Time-course experiments revealed that a short cAMP stimulation augmented threonine phosphorylation of P450c17 but did not increase 17,20-lyase activity. By contrast, long cAMP stimulation increased androgen production through increased P450c17 activities by enhancing CYP17A1 gene expression. We conclude that serum withdrawal shifts steroidogenesis of H295R cells towards androgen production, providing a suitable model for detailed studies of androgen regulation. In addition, our study shows that starvation and cAMP stimulation regulate P450c17 phosphorylation differentially and that an increase in P450c17 phosphorylation does not necessarily lead to enhanced enzyme activity and androgen production.

Redefining hormone resistance in prostate cancer.

Prostate cancer relies on signaling through the androgen receptor (AR) for maintenance and progression; and androgen-deprivation therapy remains a cornerstone of treatment for advanced prostate cancer. An effective clinical classification of prostate cancer should account for the extent of the disease as well as the mechanisms that are driving the growth of the tumor. The previous terms hormone-sensitive and hormone-refractory described response to treatment. It has become clear that these terms do not reflect the mechanism of disease relapse; however over the last decade there has been a better understanding of androgen-receptor mediated signaling effects and incomplete suppression of androgens in prostate cancer. The Prostate Cancer Clinical Trials Working Group 2 (PCWG2) now recommends addressing the spectrum of clinical states based on castration status as this ligand-centered terminology can more accurately describe the patients' disease, and ultimately provides a useful framework for patient management and drug development. Optimized use of androgen-deprivation therapy, low molecular weight inhibitors of adrenal androgen biosynthesis, and new AR antagonists are promising new therapeutics that can further define the meaning of castrate state. As hormone resistance is redefined to include patients that are refractory to treatments that ablate adrenal and in situ tumoral androgens, a meaningful new clinical state in patients will be forged. We propose a model for incorporating these patients into the current PCWG2 conceptualization of the disease.

Nonhuman primates as models for human adrenal androgen production: Function and dysfunction

The origin of circulating DHEA and adrenal-derived androgens in humans and nonhuman primates is largely distinct from other mammalian species. In humans and many Old world primates, the fetal adrenal gland and adult zona reticularis (ZR) are known to be the source for production of DHEA (and DHEAS) in mg quantities. In spite of similarities there are also some differences. Herein, we take a comparative endocrine approach to the diversity of adrenal androgen biosynthesis and its developmental timing in three primate species to illustrate how understanding such differences may provide unique insight into mechanisms underlying adrenal androgen regulation and its pathophysiology in humans. We contrast the conventional developmental onset of adrenal DHEA biosynthesis at adrenarche in humans with (1) an earlier, peri-partutrition onset of adrenal DHEA synthesis in rhesus macaques (Old World primate) and (2) a more dynamic and reversible onset of adrenal DHEA biosynthesis in female marmosets (New World primate), and further consider these events in terms of the corresponding developmental changes in expression of CYP17, HSD3B2 and CYB5 in the ZR. We also integrate these observations with recently described biochemical characterization of CYP17 cDNA cloned from each of these nonhuman primate species and the corresponding effects of phosphorylation versus CYB5 coexpression on 17,20 lyase versus 17-hydroxylase activity in each case. In addition, female rhesus macaques exposed in utero to exogenous androgen excess, exhibit symptoms of adrenal hyperandrogenism in adult females in a manner reminiscent of that seen in the human condition of PCOS. The possible mechanisms underlying such adrenal hyperandrogenism are further considered in terms of the effects of altered relative expression of CYP17, HSD3B2 and CYB5 as well as the altered signaling responses of various kinases including protein kinase A, or the insulin sensitive PI3-kinase/AKT signaling pathway which may impact on 17,20 lyase activity. We conclude that while the triggers for the onset of ZR function in all three species show clear differences (age, stage of development, social status, gender), there are still common mechanisms driving an increase in DHEA biosynthesis in each case. A full understanding of the mechanisms that control 17,20 lyase function and dysfunction in humans may best be achieved by comparative studies of the endocrine mechanisms controlling adrenal ZR function and dysfunction in these nonhuman primate species.

Phosphorylation of CtBP1 by PKA Induces CYP17 by Promoting CtBP Heterooligomerization

In the human adrenal cortex, the peptide hormone adrenocorticotropin (ACTH) directs cortisol and adrenal androgen biosynthesis by activating a cAMP/protein kinase A (PKA) pathway. Carboxy terminal binding protein 1 (CtBP1) is a corepressor that regulates transcription of the CYP17 gene by periodically interacting with steroidogenic factor‐1 (SF‐1) in response to ACTH signaling. Given that CtBP1 function is regulated by NADH binding, we hypothesized that ACTH‐stimulated changes in cellular pyridine nucleotide concentrations modulate the ability of CtBP1 to repress CYP17 transcription. Further, we postulated that PKA evokes changes in the phosphorylation status of CtBP1 that control the ability of the protein to bind to SF‐1 and repress CYP17 gene expression. We show that ACTH alters pyridine nucleotide redox state and identify amino acid residues in CtBP1 that are targeted by PKA and PAK6. Both ACTH/cAMP signaling and NADH/NAD+ ratio stimulate nuclear‐cytoplasmic oscillation of both CtBP proteins. We provide evidence that PKA 1) induces metabolic changes in the adrenal cortex and 2) phosphorylates CtBP proteins, particularly CtBP1 at T144, resulting in ACTH‐dependent CYP17 transcription.

Phosphorylation of CtBP1 by cAMP-dependent Protein Kinase Modulates Induction of CYP17 by Stimulating Partnering of CtBP1 and 2

In the human adrenal cortex, the peptide hormone adrenocorticotropin (ACTH) directs cortisol and adrenal androgen biosynthesis by activating a cAMP/cAMP-dependent protein kinase (PKA) pathway. Carboxyl-terminal binding protein 1 (CtBP1) is a corepressor that regulates transcription of the CYP17 gene by periodically interacting with steroidogenic factor-1 in response to ACTH signaling. Given that CtBP1 function is regulated by NADH binding, we hypothesized that ACTH-stimulated changes in cellular pyridine nucleotide concentrations modulate the ability of CtBP1 to repress CYP17 transcription. Further, we postulated that PKA evokes changes in the phosphorylation status of CtBP1 that control the ability of the protein to bind to steroidogenic factor-1 and the coactivator GCN5 (general control nonderepressed 5) and repress CYP17 gene expression. We show that ACTH alters pyridine nucleotide redox state and identify amino acid residues in CtBP1 that are targeted by PKA and PAK6. Both ACTH/cAMP signaling and NADH/NAD+ ratio stimulate nuclear-cytoplasmic oscillation of both CtBP proteins. We provide evidence that PKA 1) induces metabolic changes in the adrenal cortex and 2) phosphorylates CtBP proteins, particularly CtBP1 at T144, resulting in CtBP protein partnering and ACTH-dependent CYP17 transcription.

Acne infantum as presenting symptom of congenital adrenal hyperplasia due to 11‐beta‐hydroxylase deficiency

Infantile acne is a rare condition which usually begins after the third month of life and appears mainly on the cheeks. Spontaneous healing typically occurs within 2 years. A 2-year-old boy developed acne infantum during the first days after birth; it failed to respond to topical treatment. Detailed physical examination and endocrinologic evaluation confirmed the presumed diagnosis of congenital adrenal hyperplasia (CAH), and showed it was caused by 11-beta-hydroxylase deficiency. CAH comprises a group of autosomal-recessively inherited disorders. These hereditary enzyme defects in steroid biosynthesis cause glucocorticoid deficiency and an overproduction of biosynthetic precursor steroids. Adrenal androgen biosynthesis is not impaired but shows a massive reactive overproduction due to the increased ACTH secretion within the up-regulated hypothalamo-pituitary-adrenal system. The characteristic features of CAH in male infants are demonstrated on the basis of this case report.

„Acne infantum” bei adrenogenitalem Syndrom in Folge eines 11‐beta‐Hydroxylasemangels

Infantile acne is a rare condition which usually begins after the third month of life and appears mainly on the cheeks. Spontaneous healing typically occurs within 2 years. A 2-year-old boy developed acne infantum during the first days after birth; it failed to respond to topical treatment. Detailed physical examination and endocrinologic evaluation confirmed the presumed diagnosis of congenital adrenal hyperplasia (CAH),and showed it was caused by 11-beta-hydroxylase deficiency. CAH comprises a group of autosomal-recessively inherited disorders. These hereditary enzyme defects in steroid biosynthesis cause glucocorticoid deficiency and an overproduction of biosynthetic precursor steroids. Adrenal androgen biosynthesis is not impaired but shows a massive reactive overproduction due to the increased ACTH secretion within the upregulated hypothalamo-pituitary-adrenal system. The characteristic features of CAH in male infants are demonstrated on the basis of this case report.