Endocrine Abstracts

Intra-abdominal adiposity is associated with insulin resistance and increased cardiovascular morbidity and mortality. Consequently, there is a need to identify factors involved in adipose tissue distribution. Patients with glucocorticoid (GC) excess develop a classic phenotype characterized by central, but not peripheral, obesity. Differences in gene expression between omental (om) and subcutaneous (sc) adipose tissue have been described, however, the molecular mechanisms unde...

Patients with growth hormone deficiency (GHD) have many clinical features in common with Cushing’s syndrome (glucocorticoid excess) - notably visceral obesity, insulin resistance, osteoporosis and increased vascular mortality. Within key metabolic tissues, 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) converts cortisone to the active glucocorticoid, cortisol, and thus amplifies local glucocorticoid action. We hypothesise that 11β-HSD1 expression is neg...

Intra-abdominal adiposity is associated with insulin resistance and increased cardiovascular morbidity and mortality. Differences in gene expression between omental (om) and subcutaneous (sc) adipose have been described, but molecular mechanisms underpinning differences in adipose biology are not known. Patients with glucocorticoid excess, Cushing’s syndrome, develop a phenotype characterized by central obesity. We have characterized the regulation of lipogenesis by gluco...

Rheumatoid arthritis (RA) is associated with a loss of lean mass and a corresponding increase in fat mass. How fat accumulation in RA is linked to synovial inflammation is unknown. Wnts comprise a family of secreted glycoproteins that are crucial in regulating adipocyte proliferation, apoptosis and differentiation. Recently we demonstrated that endogenously generated glucocorticoids (GCs) alter the pattern of wnt secretion by synovial fibroblasts (SFs), favouring production of...

Objective: The past 2 decades have seen advances in the surgical management of Cushing’s disease (CD). Our aim was to meet the need for current data on clinical features, long-term outcomes, and prognostic indicators.Patients and methods: We conducted a retrospective study of 71 patients treated by trans-sphenoidal surgery (TSS) for CD. All patients were operated on by the same surgeon in a single centre between 1988–2009. Diagnosis was confirm...

Glucocorticoid (GC) excess (Cushing’s syndrome) is characterized by central obesity, insulin resistance and in up to 20% of cases, non-alcoholic fatty liver disease (NAFLD). NAFLD is a progressive spectrum of disease ranging from hepatic steatosis to steatohepatitis, fibrosis and cirrhosis. Many processes contribute to lipid accumulation within heaptocytes including de novo lipogenesis which includes the rate-limiting carboxylation of acetyl CoA to malonyl-CoA by a...

Glucocorticoid (GC) production rates are elevated in obese, insulin resistant individuals. We and others have demonstrated decreased hepatic cortisol regeneration through reduced 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) activity that converts inactive cortisone to cortisol. In addition, there is enhanced cortisol clearance by A-ring reductases, (notably 5α-reductase). We have argued that these changes drive the hypothalamo-pituitary–adrenal axis a...

In peripheral target tissues, levels of active glucocorticoid hormones are controlled by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) which catalyses the reduction of cortisone to cortisol within the endoplasmic reticulum. For functional 11-ketoreductase activity, 11β-HSD1 requires the NADPH-generating enzyme hexose-6-phosphate dehydrogenase (H6PDH). Loss of 11-ketoreductase activity results in increased cortisol clearance and activation of the HPA axis wi...

Patients with glucocorticoid excess develop a phenotype characterized by central obesity, however, the impact of glucocorticoids upon the processes that regulate lipid accumulation has not been fully explored. We hypothesize that intracellular generation of cortisol from cortisone by 11b-hydroxysteroid dehydrogenase type 1 (11bHSD1) is an important regulator of lipid metabolism.In adipocytes, acetyl-CoA carboxylase 1 and 2 (ACC1/2) convert acetyl-CoA to ...

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...