Molecular regulation of adrenal androgen biosynthesis

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 $in$ $vitro$ and $in$ $vivo$ 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 $in$ $vitro$ studies on DHEA sulfation confirm that the PAPSS2 isoform crucially regulates SULT2A1. Our $in$ $vivo$ 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

Disorders of sex development: challenges for the future

No abstract available

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

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

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

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

Obesity is positively associated with dehydroepiandrosterone sulfate concentrations at 7 y in Chilean children of normal birth weight.

BACKGROUND: In low-birth-weight girls, obesity increases the risk of premature adrenarche and metabolic complications. However, the consistency of this association in normal-birth-weight children and its potential mediators remain unknown. OBJECTIVES: The objectives were to assess the associations between obesity indicators and dehydroepiandrosterone sulfate (DHEAS) at 7 y of age and to evaluate the role of hormonal markers on these associations. DESIGN: We assessed in 969 participants (6.9 y; 48% girls; all Tanner I) in the Growth and Obesity Chilean Cohort Study the associations between DHEAS and weight, BMI, waist circumference (WC), waist-to-height ratio, skinfold thickness, and percentage total fat (bioimpedance) and determined whether these associations were related to insulin, insulin-like growth factor I (IGF-I), and leptin. We also compared BMI and height growth from 0 to 7 y of age in nonobese and obese children with normal and high DHEAS (≥75th percentile) at 7 y. RESULTS: DHEAS concentrations were similar between girls (30.3 ±1.86 μg/dL) and boys (29.4 ±1.73 μg/dL) (P > 0.05); 17.3% of children were obese (BMI-for-age z score ≥2 SD). Adiposity indicators were positively and similarly associated with DHEAS [ie, BMI, β standardized regression coefficient: 0.23 (95% CI: 0.17, 0.29); WC, β standardized regression coefficient: 0.23 (95% CI: 0.16, 0.30)]; these associations were only partially related to IGF-I and leptin. Obese children had twice the risk of high DHEAS (OR: 2.16; 95% CI: 1.51, 3.09); at 7 y, obese children with high DHEAS were fatter and more centrally obese than their counterparts (P 0.05). None of the results differed by sex (P > 0.05). CONCLUSION: In children of normal birth weight, obesity is positively associated with DHEAS at 7 y of age

The Regulation of Steroid Action by Sulfation and Desulfation

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

Skn1 and Ipt1 negatively regulate autophagy in Saccharomyces cerevisiae

We demonstrated that a yeast deletion mutant in IPT1 and SKN1 , encoding proteins involved in the biosynthesis of mannosyldiinositolphosphoryl ceramides, is characterized by increased autophagy and DNA fragmentation upon nitrogen (N) starvation as compared with the single deletion mutants or wild type (WT). Apoptotic features were not significantly different between single and double deletion mutants upon N starvation, pointing to increased autophagy in the double Δ ipt1 Δ skn1 deletion mutant independent of apoptosis. We observed increased basal levels of phytosphingosine in membranes of the double Δ ipt1 Δ skn1 deletion mutant as compared with the single deletion mutants or WT. These data point to a negative regulation of autophagy by both Ipt1 and Skn1 in yeast, with a putative involvement of phytosphingosine in this process.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78623/1/j.1574-6968.2009.01869.x.pd

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

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 11β-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 11β-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