Endocrine Abstracts

Aldosterone synthesis is heritable; a single nucleotide polymorphism (SNP) in the promoter of the aldosterone synthase gene (position −344, rs1799998) has been associated with an increased plasma aldosterone levels and hypertension. However, deletion of this site has no effect on gene transcription in vitro and therefore the mechanism that links genotype with phenotype is unclear.We identified a polymorphism at position −1651 T/C (rs13...

Dynamic changes in gene expression patterns and cell behaviour are evident throughout embryonic and neonatal germ cell development in the mouse. In the testes, the postnatal period represents a time when the male germline stem cells (GSCs) or, gonocytes migrate to the basement membrane of the seminiferous tubules preparing for a lifetime of spermatogenesis and is an important area of study. Here we use the transgenic mouse that expresses green fluorescent protein under the Oct...

Aim: In chronic kidney disease (CKD) elevated aldosterone (Aldo) levels are a poor prognostic indicator, particularly in the context of a high dietary sodium intake, through unclear mechanisms. Blockade of the mineralocorticoid receptor (MR) improves surrogate patient outcomes. We hypothesised that regulation of aldosterone biosynthesis is disordered in CKD and aimed to compare this in a cohort of patients with CKD with subjects with essential hypertension (EH).<p class="a...

Background: Increased levels of cortisol are associated with worse prognosis in heart failure (HF). The final step in cortisol production is catalysed by 11β-hydroxylase encoded by CYP11B1, which is highly homologous with CYP11B2. A common polymorphism in the aldosterone synthase gene (CYP11B2 −344T) is associated with a raised ratio of 11-deoxycortisol/ cortisol (S/F). We examined the relationship between −344C/T polymorphism and corticos...

The CYP11B1 and CYP11B2 genes encode 11β-hydroxylase and aldosterone synthase, which catalyse the production of cortisol and aldosterone, respectively, and have been implicated in the development of hypertension. For this study, we wished to investigate the role of microRNAs (miRNAs), a novel class of post-transcriptional gene regulators. To that end, we generated a profile of human adrenal miRNAs to study, and then investigated the action of one adrenal miR...

Previous studies investigating steroidogenic enzymes in the brain have often focused on only a few genes at a time, using animal models or pooled human RNA to investigate their expression. For this study, we obtained RNA from individual archived human brain tissue samples in order to analyse the transcription of twelve genes involved with steroid biosynthesis and metabolism within the cerebellum and hippocampus.We developed realtime RT-PCR assays for twe...

Background: Aldosterone levels in plasma are reported to be associated with risk of hypertension. Aldosterone secretion from the zona glomerulosa is regulated acutely by the renin/angiotensin system and plasma potassium. The role of ACTH in regulation of aldosterone secretion is disputed.Aim: We have utilised a large population study of middle aged adults to test the extent to which acute aldosterone responses to ACTH are associated with cortisol respons...

Aldosterone is key in the development of hypertension. We have shown that a SNP (−344T) in the 5’ regulatory region (UTR) of the gene encoding aldosterone synthase (CYP11B2) was associated with aldosterone excess and high blood pressure. However, the most robust phenotype is altered adrenal 11-hydroxylation efficiency (deoxycortisol to cortisol); a step carried out by 11β-hydroxylase, encoded by the adjacent gene, CYP11B1. We proposed that the effects of CYP11B...

(This poster is based on OC19)...

Recent genome-wide association studies (GWAS) implicate the CYP17A1 locus in human blood pressure regulation. This gene is important in steroidogenesis, regulating both glucocorticoid and androgen synthesis through catalysis of 17α-hydroxylation and 17,20 lyase reactions. We hypothesised that functional CYP17A1 polymorphisms linked to those identified by GWAS influence blood pressure levels. We therefore screened the entire CYP17A1 locus by dire...