ESPE Abstracts

Background: Patients with 21-hydroxylase deficiency (21OHD) require life-long glucocorticoid (GC) replacement and have high prevalence of metabolic disease. Our previous work using a zebrafish model of 21OHD (cyp21a2-/-) showed that cortisol-deficient adults were fertile and had normal external sex characteristics, however, they had large body size and increased subcutaneous and visceral fat deposition compared to wild-types. Unlike human 21OHD, they ...

Background: The pathophysiological link between the stress axis and mental health disorders is well established. However, the impact of inborn errors of steroidogenesis on the brain remains elusive. We analysed the brain transcriptome of adult zebrafish with impaired steroidogenesis to study the role of steroid hormones in the development of mental and psychiatric disorders.Methods: Adult brains from two established zebr...

Cytochrome P450 side-chain cleavage enzyme, encoded by the CYP11A1 gene, catalyzes the first and rate-limiting step of steroid hormone biosynthesis. Previous morpholino knockdown studies described the divergent functions of the two cyp11a paralogs in zebrafish. Cyp11a1 has been suggested to be required for early development, whereas cyp11a2 is a functional equivalent of human CYP11A1 and is essential for the initiation and maintenan...

Increasing evidence suggests that the aetiology of disorders of sex development cannot be solely explained by genetic alterations. It is highly likely that environmental factors hitting susceptible genetic backgrounds are partly causative. Zebrafish sex is highly plastic during development, making this species an ideal model for investigation of endocrine disruption and gonadal development and function. However, the hormonal regulation of these processes in zebrafish is poorly...

Background: Steroid 21-hydroxylase deficiency (21OHD) is the most common form of congenital adrenal hyperplasia. Patients present with cortisol and aldosterone deficiency as well as with hyperandrogenism, leading to virilisation in females and early adrenarche in both sexes. Requiring life-long glucocorticoid (GC) replacement, patients frequently experience daily fluctuations between GC overexposure and deficiency. Increased prevalence of metabolic disease con...

The zebrafish is established as an important model system for studying development and disease, and characterisation of the developmental and functional roles of steroids is crucial for its effective employment in this remit. Whilst oestrogens are known to be essential for female development in zebrafish, the roles of androgens in the development, maintenance and function of the male reproductive system remain unclear.In order to investigate these proces...

Glucocorticoids regulate a wide range of biological processes including metabolism. Patients with adrenal insufficiency show impaired glucocorticoid biosynthesis either caused by adrenal defects (primary adrenal insufficiency) or by defects in the pituitary gland or hypothalamus (secondary or tertiary adrenal insufficiency). The systemic consequences of differentially disrupted steroid hormone biosynthesis remain unclear. Increasing evidence suggested steroid hormone precursor...

Background: The survival of an organism relies on its ability to promptly, effectively and reproducibly communicate with brain networks that control food intake and energy homeostasis. To achieve this, circulating factors of hunger and satiety reflecting nutrient availability must cross the blood-brain barrier (BBB) to reach effectors neurons.Objective and hypotheses: Here I will discuss the key role played in this process by a peculiar type of glial cel...

Background: Transient hypothyroxinaemia of prematurity (THOP), defined as low levels of FT4 without the expected TSH surge, may concern up to 50% of infants born <30 weeks’ gestational age. Most studies showed a link between THOP and impaired neurodevelopment, as shown in the review of Eerdekens. Data about the benefit of supplementation are scarce, with few randomised trials and inconclusive results. To date, there are no clear recommendations regard...

Background: Permanent adrenal insufficiency (AI) is an uncommon but potentially life-threatening condition in children. Patients are at particular risk during times of stress. Thus, caregivers should have good illness management skills. Despite frequent teaching and seemingly good knowledge of illness management we still see a reluctance of caregivers to administer intramuscular (IM) hydrocortisone at home when indicated, preferring instead to drive themselves...