The androgen precursors, dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS) are produced in high amounts by the adrenal cortex primarily in humans and a few other primates. The human adrenal also secretes 11-oxygenated androgens (11-oxyandrogens), including 11βhydroxyandrostenedione (11OHA4), 11-ketoandrostenedione (11KA4), 11β-hydroxytestosterone (11OHT) and 11-ketotestosterone (11KT), of which 11OHT and 11KT are bioactive androgens. The 11-oxyandrogens, particularly 11KT, have been recognized as biologically important testicular androgens in teleost fishes for decades, but their physiological contribution in humans has only recently been established. Beyond fish and humans, however, the presence of 11oxyandrogens in other species has not been investigated. This study provides a comprehensive analysis of a set of C 19 steroids, including the traditional androgens and 11-oxyandrogens, across 18 animal species. As previously shown, serum DHEA and DHEAS were much higher in primates than all other species. Circulating 11-oxyandrogens, especially 11KT, were observed in notable amounts in male, but not in female trout, consistent with gonadal origin in fish. The circulating concentrations of 11-oxyandrogens ranged from 0.1 to 10 nM in pigs, guinea pigs and in all the primates studied (rhesus macaque, baboon, chimpanzee and human) but not in rats or mice, and 11OHA4 was consistently the most abundant. In contrast to fish, serum 11KT concentrations were similar in male and female primates for each species, despite significantly higher circulating testosterone in males, suggesting that 11KT production in these species is not testis-dependent and primarily originates adrenal-derived 11-oxyandrogen precursors.

Background Cytochrome P450c17 (17α-hydroxylase, encoded by CYP17A1) and cytochrome P450c11 (11β-hydroxylase, encoded by CYP11B1) are essential for production of adrenal cortisol. The expression of CYP17A1 and CYP11B1 in adrenocortical cells is stimulated by adrenocorticotropic hormone (ACTH) through the cAMP and protein kinase A signal transduction pathway. Several growth factors can act as autocrine/paracrine regulators for modulating the steroidogenesis in the adrenal cortex. Among these factors, bone morphogenetic protein-4 (BMP4), a member of the superfamily of transforming growth factor-beta (TGFβ) has been previously reported to have an inhibitory effect on adrenal cell CYP17A1 expression and dehydroepiandrosterone (DHEA) production [1]. The role of BMP4 within the adrenal and its mechanisms regulating steroidogenesis are still unclear. In the present study, we examined human adrenal expression of BMP4 and its chronic effects on the H295R adrenal cell line. Objective To define the autocrine/paracrine role of BMP4 in adrenocortical zonation and adrenal steroidogenesis. Methods BMP4 expression in normal human adrenal glands was studied using microarray analysis with laser-captured adrenal capsule and cortical zones. Adrenal BMP4 protein expression was examined following immunohistochemistry (IHC) with a rabbit polyclonal antibody against human BMP4. In vitro studies were performed using H295R and human adrenal cells treated with or without ACTH (10nM), forskolin (10 µM) and BMP4 (50 ng/mL). The experimental medium was collected every 24 h and analyzed for cortisol. Experiments were terminated at 96 h followed by isolation of RNA and qPCR analysis for PPIA (normalization transcript), cytochrome P450 cholesterol side-chain cleavage (CYP11A1), CYP17A1 and CYP11B1. Results Microarray analysis of adrenal zone RNA demonstrated a BMP4 expression gradient with zona glomerulosa (ZG) expressing 3 and 11-fold higher levels than the zona fasciculata (ZF) and zona reticularis (ZR), respectively. IHC confirmed that BMP4 expression was highest in the ZG and the outer ZF. Administration of BMP4 to cultures of H295R cells caused a significant decrease in basal and forskolin-stimulated cortisol production at 48 h. By 96 h, BMP4 inhibited forskolin-stimulated cortisol by 60%. Cortisol inhibition occurred in conjunction with an inhibition in forskolin-stimulated CYP17A1 (↓75%) and CYP11B1 (↓65%). However, CYP11A1 expression was unaffected. In primary cultures of human adrenal cells BMP4 inhibited the ability of ACTH to increase cortisol production (↓75%), as well as CYP11B1(↓65%) and CYP17A1 (↓57%) expression. Conclusion Our findings indicate that the human adrenal has outer cortex localized expression of BMP4 that could play a paracrine/autocrine role in zone-specific production of aldosterone vs. cortisol through BMP4 selective inhibition of CYP17A1 and CYP11B1. Bibliography: 1. Rege J, Nishimoto HK, Nishimoto K, Rodgers RJ, Auchus RJ, Rainey WE. Bone Morphogenetic Protein-4 (BMP4): A Paracrine Regulator of Human Adrenal C19 Steroid Synthesis. Endocrinology 2015; 156: 2530–2540. Presentation: Sunday, June 12, 2022 12:00 p.m. - 12:15 p.m.

Background: Primary aldosteronism (PA) is the most common cause of secondary hypertension, accounting for 5-8% of all hypertension. PA is most commonly attributed to an aldosterone-producing adenoma (APA) or to bilateral hyperaldosteronism (BHA). Mutations in the inward-rectifying K+ channel (mKCNJ5), which increase autonomous aldosterone production, are most frequently detected in APAs. APAs with mKCNJ5 display aberrant expression of aldosterone synthase (CYP11B2) and 17α-hydroxylase (CYP17A1), which are involved in aldosterone and cortisol synthesis, respectively. Co-expression of these enzymes results in the production of a set of “hybrid” steroids, which have been proposed as serum biomarkers. The relative production of hybrid steroids in adrenal tumors vs. adjacent normal adrenal (NA) tissue has not been investigated. Objectives: To determine the utility of OCT-embedded adrenal tumor tissue for steroid profiling. To use immunohistochemistry (IHC)-guided OCT tumor capture for intratumoral hybrid steroid profiling in mKCNJ5 APA and NA tissue. Methods: OCT-embedded adrenal tissue from 9 patients (8 women, Age 45.9 ± 3.3 years) with APAs harboring known KCNJ5 mutations were used for the study. Where available OCT-embedded normal adrenal (NA) tissue adjacent to APAs were used as controls (n=4). IHC was performed for CYP11B2 and CYP17A1 on OCT tissue allowing guided APA capture from serial sections. Steroids were extracted from APA and adjacent NA tissue, and quantified by liquid chromatography/tandem mass spectrometry. Steroids measured were normalized to the protein content of the extracted tissue. Results: Compared to NA, APA tissue demonstrated 23-, 5.6- and 6.4-fold higher levels of aldosterone, 11-deoxycorticosterone, and 18-hydroxycorticosterone, respectively (P<0.05). In addition, the “hybrid” steroid products, 18-oxocortisol and 18-hydroxycortisol, were significantly elevated in APA vs. NA (P<0.01). Conversely, the adrenal androgens dehydroepiandrosterone and 11-hydroxyandrostenedione were lower in APA as compared with NA (P<0.05). All mKCNJ5 APAs were also found to co-express CYP11B2 and CYP17A1. Conclusion: IHC-guided mKCNJ5 APA capture and steroid extraction identified a distinct intratumoral hybrid steroid signature that associated with co-expression of CYP11B2 and CYP17A1.These findings also demonstrate that OCT-embedded tissue can be used to accurately define intra-tissue steroid profiles, which will have application for steroid-producing and steroid-responsive tumors.

Background: The term “adrenal androgen” is often used to describe the adrenal-produced androgen precursors, dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS). The human adrenal, however, also secretes 11-oxygenated androgens that include 11-hydroxyandrostenedione (11OHA4), 11-ketoandrostenedione (11KA4), 11-hydroxytestosterone (11OHT) and 11-ketotestosterone (11KT), of which 11OHT and 11KT are bioactive. These clinically important steroids have been implicated in diseases of androgen excess, including premature adrenarche, congenital adrenal hyperplasia and polycystic ovary syndrome. While the production of these steroids is established in humans, their presence in other mammalian species has not been examined. Objectives: The goal of this study was to characterize circulating 11-oxyandrogens across species and identify possible animal models to study the regulation and functions of these steroids. Methods: To eliminate possible confounding contributions of testicular androgens, serum was obtained from a range of adult female animals, including birds, rodents, domestic animals and primates (15 species, n=5 each). Sera concentrations of DHEA, DHEAS, 11OHA4, 11KA4, 11OHT and 11KT were analyzed by liquid chromatography-tandem mass spectrometry. Results: As previously demonstrated, significant amounts of circulating DHEA and DHEAS were found only in primates. 11-oxyandrogens also circulated at similar concentrations in all the primates studied (rhesus monkeys, baboons, chimpanzees and humans) of which 11OHA4 was observed to be the most abundant circulating steroid. As expected, neither rats or mice had circulating 11-oxyandrogens, likely because they lack adrenal 17α-hydroxylase/17,20-lyase expression. Low levels of 11-oxyandrogens were detected in dogs, cows, sheep and horses. Interestingly, pigs and guinea pigs had significant circulating levels of 11-oxyandrogens. Circulating levels of 11OHA4 and 11KA4 in pigs (3.2 ± 0.8 nM; 0.4 ± 0.1 nM respectively) and guinea pigs (7.0 ± 0.2 nM; 1.2 ± 0.1 nM) were similar or higher than humans (3.4 ± 0.6 nM; 0.4 ± 0.1 nM). Serum concentrations of 11OHT in guinea pigs were lower (0.1 ± 0.02 nM) as compared to humans (0.3 ± 0.04 nM) and pigs (0.5 ± 0.2 nM). Conversely, circulating 11KT levels were most abundant in humans (0.7 ± 0.2 nM), followed by guinea pigs (0.4 ± 0.1 nM) and pigs (0.2 ± 0.03 nM). Conclusions: 11-oxygenated androgens are produced in multiple primate species. In addition, guinea pigs and pigs have circulating concentrations of 11-oxyandrogens similar to those seen in primates, and could be considered as appropriate animal models to define the physiology of the 11-oxyandrogens.