Endocrine Abstracts

The glucocorticoid (GC) activating enzyme 11β-HSD1 is potently upregulated within macrophages and synovial fibroblasts of inflamed joints, where it increases therapeutic GC signalling and regulates their anti-inflammatory profiles. Whilst in vitro studies have demonstrated the importance of autocrine signalling in this context, the importance of paracrine signalling remains poorly defined. In this study, we examined the role of 11β-HSD1 in paracrine GC signalling bet...

Muscle wasting is a common feature of inflammatory myopathies. Glucocorticoids (GCs), whilst effective at suppressing inflammation and inflammatory muscle loss, also cause myopathy with prolonged administration. 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is a bidirectional GC activating enzyme, potently up-regulated by inflammation within mesenchymal derived tissues. We assessed the regulation of this enzyme with inflammation in muscle and examined its functi...

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...

Acute inflammation plays an important role in the normal immune system by helping to coordinate host responses to danger signals such as infection. In most cases the inflammation is rapidly resolved but in chronic inflammatory diseases such as rheumatoid arthritis (RA) the inflammation persists leading to localized accumulation of potentially damaging immune cells. It remains unclear why inflammation persists in some tissues and not in others. Recent studies have shown that st...

Generalised and periarticular osteoporosis are common features of inflammatory arthritides. These effects appear due to high levels of pro-inflammatory cytokines. 11beta-hydroxysteroid dehydrogenase type 1 (11b-HSD1) is an intracellular enzyme that generates active cortisol from inactive cortisone and is an important determinant of the effects of glucocorticoids on osteoblasts. In vitro, osteoblastic 11b-HSD1 expression is induced by pro-inflammatory cytokines. We thus ...

Fibroblasts are important regulators of local inflammatory responses. These responses are further regulated by tissue glucocorticoid levels. Other stromal lineage cells, adipocytes and osteoblasts, express 11beta-hydroxysteroid dehydrogenases (11b-HSDs) which interconvert inactive cortisone and active cortisol. These enzymes are important regulators of local glucocorticoid levels and their expression is regulated by proinflammatory cytokines. We therefore examined expression o...

Muscle wasting remains a significant complication in patients with inflammatory disease where it contributes to disability, risk of falls and early mortality. Interestingly, muscle wasting in patients with glucocorticoid excess mirrors that observed in patients with inflammatory disease. We have previously reported that the glucocorticoid activating enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is potently up-regulated within mesenchymal derived cell popu...

Synovial fibroblasts (SFs) form a substantial component of inflamed rheumatoid synovium and generate endogenous glucocorticoids (GCs) during inflammation. Recently, production of DKK-1 (a Wnt signalling inhibitor that reduces bone formation) by SFs in response to TNFα has been proposed to be the master regulator of inflammatory osteoporosis. We have identified that in addition to TNFα, GCs potently induce DKK-1 secretion. This may provide a novel mechanism whereby lo...

We have previously proposed a central role for locally generated glucocorticoids in the periarticular and systemic osteoporosis seen in rheumatoid arthritis (RA). Synovial fibroblasts (SFs) express the 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) enzyme and this expression increases dramatically with inflammation. Recently, production of DKK-1 (a Wnt signalling inhibitor known to inhibit bone formation) by SFs in response to inflammation has been proposed to ex...

Variation in endogenous glucocorticoid (GC) activity during inflammation has been linked to susceptibility to developing rheumatoid arthritis (RA). It has been shown that in patients with RA inflamed synovial tissue can generate active GCs through the expression of the 11β-hydroxysteroid dehydrogenase type 1 enzyme (11β-HSD1), which converts cortisone to cortisol. We examined whether the total body activity of 11β-HSD1 or its expression within synovium was assoc...