41 research outputs found

    Molecular regulation of adrenal androgen biosynthesis

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    The biosynthesis of adrenal androgens is catalysed by steroid-modifying enzymes. Over the past decade, co-factors were explored to regulate these enzymes: P450 oxidoreductase (POR) delivers electrons to the key androgen-producing cytochrome P450 enzyme CYP17A1. In addition, sulfation of the principal androgen precursor dehydroepiandrosterone (DHEA) catalysed by the enzyme SULT2A1, supported by its co-factor 3’-phosphoadenosine-5’-phosphosulfate (PAPS) synthase 2 (PAPSS2), has been found more recently as a gatekeeper of androgen activation. Here, we have further characterised children with defects of enzymes of the androgen pathway, namely CYP17A1 and POR. We report the first human missense mutation of cytochrome b5, which supports electron transfer from POR to CYP17A1. In addition, we have explored the molecular regulation of DHEA sulfation by inin vitrovitro and inin vivovivo studies. The results from our studies provide important information on the clinical course, the diagnostic steroid fingerprint and underlying molecular mechanisms of conditions affecting androgen generation. The inin vitrovitro studies on DHEA sulfation confirm that the PAPSS2 isoform crucially regulates SULT2A1. Our inin vivovivo study in children with deficiencies of the steroid sulfatase (STS) enzyme, the counterpart of SULT2A1, suggests that STS does not play a major role in DHEA metabolism but is more active before puberty

    Management aspects of congenital adrenal hyperplasia during adolescence and transition to adult care

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    The adolescent period is characterised by fundamental hormonal changes, which affect sex steroid production, cortisol metabolism and insulin sensitivity. These physiological changes have a significant impact on patients with congenital adrenal hyperplasia (CAH). An essential treatment aim across the lifespan in patients with CAH is to replace glucocorticoids sufficiently to avoid excess adrenal androgen production but equally to avoid cardiometabolic risks associated with excess glucocorticoid intake. The changes to the hormonal milieu at puberty, combined with poor adherence to medical therapy, often result in unsatisfactory control exacerbating androgen excess and increasing the risk of metabolic complications due to steroid over‐replacement. With the physical and cognitive maturation of the adolescent with CAH, fertility issues and sexual function become a new focus of patient care in the paediatric clinic. This requires close surveillance for gonadal dysfunction, such as irregular periods/hirsutism or genital surgery‐associated symptoms in girls and central hypogonadism or testicular adrenal rest tumours in boys. To ensure good health outcomes across the lifespan, the transition process from paediatric to adult care of patients with CAH must be planned carefully and early from the beginning of adolescence, spanning over many years into young adulthood. Its key aims are to empower the young person through education with full disclosure of their medical history, to ensure appropriate follow‐up with experienced physicians and facilitate access to multispecialist teams addressing the complex needs of patients with CAH

    The Regulation of Steroid Action by Sulfation and Desulfation

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    Steroid sulfation and desulfation are fundamental pathways vital for a functional vertebrate endocrine system. After biosynthesis, hydrophobic steroids are sulfated to expedite circulatory transit. Target cells express transmembrane organic anion-transporting polypeptides that facilitate cellular uptake of sulfated steroids. Once intracellular, sulfatases hydrolyze these steroid sulfate esters to their unconjugated, and usually active, forms. Because most steroids can be sulfated, including cholesterol, pregnenolone, dehydroepiandrosterone, and estrone, understanding the function, tissue distribution, and regulation of sulfation and desulfation processes provides significant insights into normal endocrine function. Not surprisingly, dysregulation of these pathways is associated with numerous pathologies, including steroid-dependent cancers, polycystic ovary syndrome, and X-linked ichthyosis. Here we provide a comprehensive examination of our current knowledge of endocrine-related sulfation and desulfation pathways. We describe the interplay between sulfatases and sulfotransferases, showing how their expression and regulation influences steroid action. Furthermore, we address the role that organic anion-transporting polypeptides play in regulating intracellular steroid concentrations and how their expression patterns influence many pathologies, especially cancer. Finally, the recent advances in pharmacologically targeting steroidogenic pathways will be examined

    Evidence for Increased 5α-Reductase Activity During Early Childhood in Daughters of Women with Polycystic Ovary Syndrome

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    CONTEXT: Polycystic ovary syndrome (PCOS) is a heritable, complex genetic disease. Animal models suggest that androgen exposure at critical developmental stages contributes to disease pathogenesis. We hypothesized that genetic variation resulting in increased androgen production produces the phenotypic features of PCOS by programming during critical developmental periods. Although we have not found evidence for increased in utero androgen levels in cord blood in the daughters of women with PCOS (PCOS-d), target tissue androgen production may be amplified by increased 5α-reductase activity analogous to findings in adult affected women. It is possible to noninvasively test this hypothesis by examining urinary steroid metabolites. OBJECTIVE: We performed this study to investigate whether PCOS-d have altered androgen metabolism during early childhood. DESIGN, SETTING, AND PARTICIPANTS: Twenty-one PCOS-d, 1–3 years old, and 36 control girls of comparable age were studied at an academic medical center. MAIN OUTCOME MEASURES: Urinary steroid metabolites were measured by gas chromatography/mass spectrometry. Twenty-four hour steroid excretion rates and precursor to product ratios suggestive of 5α-reductase and 11ÎČ-hydroxysteroid dehydrogenase activities were calculated. RESULTS: Age did not differ but weight for length Z-scores were higher in PCOS-d compared to control girls (P = .02). PCOS-d had increased 5α-tetrahydrocortisol:tetrahydrocortisol ratios (P = .04), suggesting increased global 5α-reductase activity. There was no evidence for differences in 11ÎČ-hydroxysteroid dehydrogenase activity. Steroid metabolite excretion was not correlated with weight. CONCLUSIONS: Our findings suggest that differences in androgen metabolism are present in early childhood in PCOS-d. Increased 5α-reductase activity could contribute to the development of PCOS by amplifying target tissue androgen action

    Pubertal presentation in seven patients with congenital adrenal hyperplasia due to P450 Oxidoreductase deficiency

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    Context: P450 oxidoreductase (POR) is a crucial electron donor to all microsomal P450 cytochrome (CYP) enzymes including 17α-hydroxylase (CYP17A1), 21-hydroxylase (CYP21A2) and P450 aromatase. Mutant POR causes congenital adrenal hyperplasia with combined glucocorticoid and sex steroid deficiency. P450 oxidoreductase deficiency (ORD) commonly presents neonatally, with disordered sex development in both sexes, skeletal malformations, and glucocorticoid deficiency. \ud \ud Objective: The aim of the study was to describe the clinical and biochemical characteristics of ORD during puberty. \ud \ud Design: Clinical, biochemical, and genetic assessment of seven ORD patients (five females, two males) presenting during puberty was conducted. \ud \ud Results: Predominant findings in females were incomplete pubertal development (four of five) and large ovarian cysts (five of five) prone to spontaneous rupture, in some only resolving after combined treatment with estrogen/progestin, GnRH superagonists, and glucocorticoids. Pubertal development in the two boys was more mildly affected, with some spontaneous progression. Urinary steroid profiling revealed combined CYP17A1 and CYP21A2 deficiencies indicative of ORD in all patients; all but one failed to mount an appropriate cortisol response to ACTH stimulation indicative of adrenal insufficiency. Diagnosis of ORD was confirmed by direct sequencing, demonstrating disease-causing POR mutations. \ud \ud Conclusion: Delayed and disordered puberty can be the first sign leading to a diagnosis of ORD. Appropriate testosterone production during puberty in affected boys but manifest primary hypogonadism in girls with ORD may indicate that testicular steroidogenesis is less dependent on POR than adrenal and ovarian steroidogenesis. Ovarian cysts in pubertal girls may be driven not only by high gonadotropins but possibly also by impaired CYP51A1-mediated production of meiosis-activating sterols due to mutant POR

    Causes, patterns and severity of androgen excess in 487 consecutively recruited pre- and post-pubertal children

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    Objective Androgen excess in childhood is a common presentation and may signify sinister underlying pathology. Data describing its patterns and severity are scarce, limiting the information available for clinical decision processes. Here, we examined the differential diagnostic value of serum DHEAS, androstenedione (A4) and testosterone in childhood androgen excess. Design Retrospective review of all children undergoing serum androgen measurement at a single center over 5 years. Methods Serum A4 and testosterone were measured by tandem mass spectrometry and DHEAS by immunoassay. Patients with at least one increased androgen underwent phenotyping by clinical notes review. Results In 487 children with simultaneous DHEAS, A4 and testosterone measurements, we identified 199 with androgen excess (140 pre- and 59 post-pubertal). Premature adrenarche (PA) was the most common pre-pubertal diagnosis (61%), characterized by DHEAS excess in 85%, while A4 and testosterone were only increased in 26 and 9% respectively. PCOS was diagnosed in 40% of post-pubertal subjects, presenting equally frequent with isolated excess of DHEAS (29%) or testosterone (25%) or increases in both A4 and testosterone (25%). CAH patients (6%) predominantly had A4 excess (86%); testosterone and DHEAS were increased in 50 and 33% respectively. Concentrations increased above the two-fold upper limit of normal were mostly observed in PA for serum DHEAS (&gt;20-fold in the single case of adrenocortical carcinoma) and in CAH for serum androstenedione. Conclusions Patterns and severity of childhood androgen excess provide pointers to the underlying diagnosis and can be used to guide further investigations.</p

    Isosexual precocious pseudopuberty during mitotane treatment in a child with adrenocortical carcinoma:A case report

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    Background Mitotane is employed as adjuvant therapy in managing adrenocortical carcinoma in pediatric patients. While various adverse effects, such as estrogen-like manifestations, are well-documented in adults, there is limited knowledge regarding pediatric-specific toxicity. This report details an uncommon case of isosexual precocious pseudopuberty induced during childhood due to the estrogen-like effects of mitotane. Case report A 2.8-year-old female diagnosed with adrenocortical carcinoma (pT4 pN0 M0) underwent adjuvant treatment with mitotane and cytotoxic chemotherapy following incomplete resection (tumor stage III). Approximately eight months into mitotane treatment, she exhibited signs of puberty (Tanner stage 2), including progressive breast development, uterine enlargement, vaginal discharge, and an advancement of bone age by nearly two years. Gonadotrophin-dependent puberty and endogenous estrogen production were ruled out. The precocious pseudopuberty was attributed to previously reported estrogen-like effects of mitotane therapy. Subsequent administration of the aromatase inhibitor anastrozole in combination with mitotane led to a reduction in clinical signs of puberty. Conclusion Monitoring for estrogen-like effects of mitotane is crucial, particularly in pre-pubertal children, to avert potentially irreversible changes associated with precocious pseudopuberty. Aromatase inhibitors may serve as a prompt therapeutic option, enabling the continuation of mitotane treatment

    Steroid sulfatase sulfatase deficiency and androgen activation before and after puberty

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    CONTEXT: Steroid sulfatase (STS) cleaves the sulfate moiety off steroid sulfates, including dehydroepiandrosterone (DHEA) sulfate (DHEAS), the inactive sulfate ester of the adrenal androgen precursor DHEA. Deficient DHEA sulfation, the opposite enzymatic reaction to that catalyzed by STS, results in androgen excess by increased conversion of DHEA to active androgens. STS deficiency (STSD) due to deletions or inactivating mutations in the X-linked STS gene manifests with ichthyosis, but androgen synthesis and metabolism in STSD have not been studied in detail yet. PATIENTS AND METHODS: We carried out a cross-sectional study in 30 males with STSD (age 6–27 y; 13 prepubertal, 5 peripubertal, and 12 postpubertal) and 38 age-, sex-, and Tanner stage-matched healthy controls. Serum and 24-hour urine steroid metabolome analysis was performed by mass spectrometry and genetic analysis of the STS gene by multiplex ligation-dependent probe amplification and Sanger sequencing. RESULTS: Genetic analysis showed STS mutations in all patients, comprising 27 complete gene deletions, 1 intragenic deletion and 2 missense mutations. STSD patients had apparently normal pubertal development. Serum and 24-hour urinary DHEAS were increased in STSD, whereas serum DHEA and testosterone were decreased. However, total 24-hour urinary androgen excretion was similar to controls, with evidence of increased 5α-reductase activity in STSD. Prepubertal healthy controls showed a marked increase in the serum DHEA to DHEAS ratio that was absent in postpubertal controls and in STSD patients of any pubertal stage. CONCLUSIONS: In STSD patients, an increased 5α-reductase activity appears to compensate for a reduced rate of androgen generation by enhancing peripheral androgen activation in affected patients. In healthy controls, we discovered a prepubertal surge in the serum DHEA to DHEAS ratio that was absent in STSD, indicative of physiologically up-regulated STS activity before puberty. This may represent a fine tuning mechanism for tissue-specific androgen activation preparing for the major changes in androgen production during puberty
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