Zaki Hassan-Smith

11β-HSD1 is the major regulator of the tissue-specific effects of circulating glucocorticoid excess

Significance Glucocorticoids are widely prescribed for their anti-inflammatory properties but have Cushingoid side effects that contribute significantly to patient morbidity and mortality. Here we present data to demonstrate that the adverse side-effect profile associated with exogenous active glucocorticoid (GC) administration (including glucose intolerance, hyperinsulinemia, hypertension, hepatic steatosis, increased adiposity, and myopathy) is prevented by global deletion of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) in mice. This study not only defines a significant shift in our understanding of the physiological and molecular mechanisms underpinning the adverse side effects associated with GC use but also raises the possibility of targeting 11β-HSD1 as a novel adjunctive therapy in the treatment of Cushing syndrome. The adverse metabolic effects of prescribed and endogenous glucocorticoid (GC) excess, Cushing syndrome, create a significant health burden. We found that tissue regeneration of GCs by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), rather than circulating delivery, is critical to developing the phenotype of GC excess; 11β-HSD1 KO mice with circulating GC excess are protected from the glucose intolerance, hyperinsulinemia, hepatic steatosis, adiposity, hypertension, myopathy, and dermal atrophy of Cushing syndrome. Whereas liver-specific 11β-HSD1 KO mice developed a full Cushingoid phenotype, adipose-specific 11β-HSD1 KO mice were protected from hepatic steatosis and circulating fatty acid excess. These data challenge our current view of GC action, demonstrating 11β-HSD1, particularly in adipose tissue, is key to the development of the adverse metabolic profile associated with circulating GC excess, offering 11β-HSD1 inhibition as a previously unidentified approach to treat Cushing syndrome.

Outcome of Cushing's Disease following Transsphenoidal Surgery in a Single Center over 20 Years

CONTEXT Historically, Cushings disease (CD) was associated with a 5-yr survival of just 50%. Although advances in CD management have seen mortality rates improve, outcome from transsphenoidal surgery (TSS), the current first-line treatment, varies significantly between centers. OBJECTIVES The aim of the study was to define outcome including mortality in a cohort of CD patients treated with TSS over 20 yr. DESIGN We conducted a retrospective cohort study of 80 patients who underwent TSS to treat CD between 1988 and 2009. In 72 cases, data on clinical features and outcomes were collected from medical records. In eight patients, records were unavailable, but in all cases mortality data were obtained from National Health Service (NHS) registries and recorded as standardized mortality ratio. SETTING The study was conducted in a United Kingdom tertiary referral center. PATIENTS OR OTHER PARTICIPANTS Adult patients confirmed to have CD participated in the study. INTERVENTIONS All patients underwent TSS. MAIN OUTCOME MEASURE Patients were subdivided into groups based on disease response after initial treatment. Mortality according to subgroup was also assessed. RESULTS Median follow-up for clinical data was 4.6 yr. Three outcome groups were identified: cure, 72% (52 of 72); persistent disease, 17% (12 of 72); and disease recurrence, 11% (eight of 72). Median time to recurrence after initial remission was 2.1 yr (interquartile range, 1.3-3.1 yr). Mean follow-up for mortality was 10.9 yr. Thirteen of 80 patients had died: five of 52 in the cure group, two of eight in the disease recurrence group, two of 12 with persistent disease, and four of eight of those followed up by NHS registry search only. Overall, the standardized mortality ratio was 3.17 [95% confidence interval (CI), 1.70-5.43], whereas in the cure group it was 2.47 (95% CI, 0.80-5.77), and it was 4.12 (95% CI, 1.12-10.54) for disease recurrence/persistent disease groups. CONCLUSIONS We report long-term cure rates in excess of 70%. Mortality is increased in CD and may be higher in patients with persistent/recurrent disease compared to patients cured after initial treatment.

11β-Hydroxysteroid dehydrogenase blockade prevents age-induced skin structure and function defects

Glucocorticoid (GC) excess adversely affects skin integrity, inducing thinning and impaired wound healing. Aged skin, particularly that which has been photo-exposed, shares a similar phenotype. Previously, we demonstrated age-induced expression of the GC-activating enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) in cultured human dermal fibroblasts (HDFs). Here, we determined 11β-HSD1 levels in human skin biopsies from young and older volunteers and examined the aged 11β-HSD1 KO mouse skin phenotype. 11β-HSD1 activity was elevated in aged human and mouse skin and in PE compared with donor-matched photo-protected human biopsies. Age-induced dermal atrophy with deranged collagen structural organization was prevented in 11β-HSD1 KO mice, which also exhibited increased collagen density. We found that treatment of HDFs with physiological concentrations of cortisol inhibited rate-limiting steps in collagen biosynthesis and processing. Furthermore, topical 11β-HSD1 inhibitor treatment accelerated healing of full-thickness mouse dorsal wounds, with improved healing also observed in aged 11β-HSD1 KO mice. These findings suggest that elevated 11β-HSD1 activity in aging skin leads to increased local GC generation, which may account for adverse changes occurring in the elderly, and 11β-HSD1 inhibitors may be useful in the treatment of age-associated impairments in dermal integrity and wound healing.

Inflammatory regulation of glucocorticoid metabolism in mesenchymal stromal cells

Abstract Objective Tissue glucocorticoid (GC) levels are regulated by the GC-activating enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1). This enzyme is expressed in cells and tissues arising from mesenchymal stromal cells. Proinflammatory cytokines dramatically increase expression of 11β-HSD1 in stromal cells, an effect that has been implicated in inflammatory arthritis, osteoporosis, obesity, and myopathy. Additionally, GCs act synergistically with proinflammatory cytokines to further increase enzyme expression. The present study was undertaken to investigate the mechanisms underlying this regulation. Methods Gene reporter analysis, rapid amplification of complementary DNA ends (RACE), chemical inhibition experiments, and genetic disruption of intracellular signaling pathways in mouse embryonic fibroblasts (MEFs) were used to define the molecular mechanisms underlying the regulation of 11β-HSD1 expression. Results Gene reporter, RACE, and chemical inhibitor studies demonstrated that the increase in 11β-HSD1 expression with tumor necrosis factor α (TNFα)/interleukin-1β (IL-1β) occurred via the proximal HSD11B1 gene promoter and depended on NF-κB signaling. These findings were confirmed using MEFs with targeted disruption of NF-κB signaling, in which RelA (p65) deletion prevented TNFα/IL-1β induction of 11β-HSD1. GC treatment did not prevent TNFα-induced NF-κB nuclear translocation. The synergistic enhancement of TNFα-induced 11β-HSD1 expression with GCs was reproduced by specific inhibitors of p38 MAPK. Inhibitor and gene deletion studies indicated that the effects of GCs on p38 MAPK activity occurred primarily through induction of dual-specificity phosphatase 1 expression. Conclusion The mechanism by which stromal cell expression of 11β-HSD1 is regulated is novel and distinct from that in other tissues. These findings open new opportunities for development of therapeutic interventions aimed at inhibiting or stimulating local GC levels in cells of mesenchymal stromal lineage during inflammation.

Steroid metabolome analysis reveals prevalent glucocorticoid excess in primary aldosteronism

BACKGROUND. Adrenal aldosterone excess is the most common cause of secondary hypertension and is associated with increased cardiovascular morbidity. However, adverse metabolic risk in primary aldosteronism extends beyond hypertension, with increased rates of insulin resistance, type 2 diabetes, and osteoporosis, which cannot be easily explained by aldosterone excess. METHODS. We performed mass spectrometry–based analysis of a 24-hour urine steroid metabolome in 174 newly diagnosed patients with primary aldosteronism (103 unilateral adenomas, 71 bilateral adrenal hyperplasias) in comparison to 162 healthy controls, 56 patients with endocrine inactive adrenal adenoma, 104 patients with mild subclinical, and 47 with clinically overt adrenal cortisol excess. We also analyzed the expression of cortisol-producing CYP11B1 and aldosterone-producing CYP11B2 enzymes in adenoma tissue from 57 patients with aldosterone-producing adenoma, employing immunohistochemistry with digital image analysis. RESULTS. Primary aldosteronism patients had significantly increased cortisol and total glucocorticoid metabolite excretion (all P < 0.001), only exceeded by glucocorticoid output in patients with clinically overt adrenal Cushing syndrome. Several surrogate parameters of metabolic risk correlated significantly with glucocorticoid but not mineralocorticoid output. Intratumoral CYP11B1 expression was significantly associated with the corresponding in vivo glucocorticoid excretion. Unilateral adrenalectomy resolved both mineralocorticoid and glucocorticoid excess. Postoperative evidence of adrenal insufficiency was found in 13 (29%) of 45 consecutively tested patients. CONCLUSION. Our data indicate that glucocorticoid cosecretion is frequently found in primary aldosteronism and contributes to associated metabolic risk. Mineralocorticoid receptor antagonist therapy alone may not be sufficient to counteract adverse metabolic risk in medically treated patients with primary aldosteronism. FUNDING. Medical Research Council UK, Wellcome Trust, European Commission.

Mortality in patients with Cushing's disease more than 10 years after remission: a multicentre, multinational, retrospective cohort study

BACKGROUND No agreement has been reached on the long-term survival prospects for patients with Cushings disease. We studied life expectancy in patients who had received curative treatment and whose hypercortisolism remained in remission for more than 10 years, and identified factors determining their survival. METHODS We did a multicentre, multinational, retrospective cohort study using individual case records from specialist referral centres in the UK, Denmark, the Netherlands, and New Zealand. Inclusion criteria for participants, who had all been in studies reported previously in peer-reviewed publications, were diagnosis and treatment of Cushings disease, being cured of hypercortisolism for a minimum of 10 years at study entry, and continuing to be cured with no relapses until the database was frozen or death. We identified the number and type of treatments used to achieve cure, and used mortality as our primary endpoint. We compared mortality rates between patients with Cushings disease and the general population, and expressed them as standardised mortality ratios (SMRs). We analysed survival data with multivariate analysis (Cox regression) with no corrections for multiple testing. FINDINGS The census dates on which the data were frozen ranged from Dec 31, 2009, to Dec 1, 2014. We obtained data for 320 patients with 3790 person-years of follow-up from 10 years after cure (female:male ratio of 3:1). The median patient follow-up was 11·8 years (IQR 17-26) from study entry and did not differ between countries. There were no significant differences in demographic characteristics, duration of follow-up, comorbidities, treatment number, or type of treatment between women and men, so we pooled data from both sexes for survival analysis. 51 (16%) of the cohort died during follow-up from study entry (10 years after cure). Median survival from study entry was similar for women (31 years; IQR 19-38) and men (28 years; 24-42), and about 40 years (IQR 30-48) from remission. The overall SMR for all-cause mortality was 1·61 (95% CI 1·23-2·12; p=0·0001). The SMR for circulatory disease was increased at 2·72 (1·88-3·95; p<0·0001), but deaths from cancer were not higher than expected (0·79, 0·41-1·51). Presence of diabetes, but not hypertension, was an independent risk factor for mortality (hazard ratio 2·82, 95% CI 1·29-6·17; p=0·0095). We noted a step-wise reduction in survival with increasing number of treatments. Patients cured by pituitary surgery alone had long-term survival similar to that of the general population (SMR 0·95, 95% CI 0·58-1·55) compared with those who were not (2·53, 1·82-3·53; p<0·0001). INTERPRETATION Patients with Cushings disease who have been in remission for more than 10 years are at increased risk of overall mortality compared with the general population, particularly from circulatory disease. However, median survival from cure is excellent at about 40 years of remission. Treatment complexity and an increased number of treatments, reflecting disease that is more difficult to control, appears to negatively affect survival. Pituitary surgery alone is the preferred treatment to secure an optimum outcome, and should be done in a centre of surgical excellence. FUNDING None.

Ghrelin Receptor Gene Polymorphisms and Body Size in Children and Adults

BACKGROUND The GH secretagogue receptor type 1a gene (GHSR) encodes the cognate receptor of ghrelin, a gut hormone that regulates food intake and pituitary GH secretion. Previous studies in U.S. families and a German population suggested GHSR to be a candidate quantitative locus for association with human obesity and growth. AIM The aim of the study was to test common genetic variation in GHSR for association with body size in children and adults. METHODS Sequencing was performed to systematically identify novel single nucleotide polymorphisms (SNPs) in GHSR. A set of three haplotype-tagging SNPs that captured all the genetic variation in GHSR was identified. These three haplotype-tagging SNPs were then genotyped in three large population-based U.K. cohort studies (two adult and one childhood cohort) comprising 5807 adults and 843 children. RESULTS No significant genotype or haplotype associations were found with adult or childhood height, weight, or body mass index. CONCLUSION Common variation in GHSR is not associated with body size in U.K. adults or children.

Gender-Specific Differences in Skeletal Muscle 11β-HSD1 Expression Across Healthy Aging.

CONTEXT Cushings syndrome is characterized by marked changes in body composition (sarcopenia, obesity, and osteoporosis) that have similarities with those seen in aging. 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) converts glucocorticoids to their active form (cortisone to cortisol in humans), resulting in local tissue amplification of effect. OBJECTIVE To evaluate 11β-HSD1 expression and activity with age, specifically in muscle. To determine putative causes for increased activity with age and its consequences upon phenotypic markers of adverse aging. DESIGN Cross-sectional observational study. SETTING National Institute for Health Research-Wellcome Trust Clinical Research Facility, Birmingham, United Kingdom. PATIENTS OR OTHER PARTICIPANTS Healthy human volunteers age 20 to 81 years (n = 134; 77 women, 57 men). INTERVENTIONS Day attendance at research facility for baseline observations, body composition analysis by dual-energy x-ray absorptiometry, jump-plate mechanography, grip strength analysis, baseline biochemical profiling, urine collection, and vastus lateralis muscle biopsy. MAIN OUTCOME MEASURE(S) Skeletal muscle gene expression, urine steroid profile, bivariate correlations between expression/activity and phenotypic/biochemical variables. RESULTS Skeletal muscle 11β-HSD1 expression was increased 2.72-fold in women over 60 years of age compared to those aged 20-40 years; no differences were observed in men. There was a significant positive correlation between skeletal muscle 11β-HSD1 expression and age in women across the group (rho = 0.40; P = .009). No differences in expression of 11β-HSD type 2, glucocorticoid receptor, or hexose-6-phosphate dehydrogenase between age groups were observed in either sex. Urinary steroid markers of 11β-HSD1, 11β-HSD type 2, or 5α-reductase were similar between age groups. Skeletal muscle 11β-HSD1 expression was associated with reduced grip strength in both sexes and correlated positively with percentage of body fat, homeostasis model of assessment for insulin resistance, total cholesterol, LH, and FSH and negatively with bone mineral content and IGF-1 in women. CONCLUSIONS Skeletal muscle 11β-HSD1 is up-regulated with age in women and is associated with reduced grip strength, insulin resistance, and an adverse body composition profile. Selective inhibition of 11β-HSD1 may offer a novel strategy to prevent and/or reverse age-related sarcopenia.

Regulation of Lipid Metabolism by Glucocorticoids and 11β-HSD1 in Skeletal Muscle

The prevalences of insulin resistance and type 2 diabetes mellitus are rising dramatically, and, as a consequence, there is an urgent need to understand the pathogenesis underpinning these conditions to develop new and more efficacious treatments. We have tested the hypothesis that glucocorticoid (GC)-mediated changes in insulin sensitivity may be associated with changes in lipid flux. Furthermore, prereceptor modulation of GC availability by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) may represent a critical regulatory step. Dexamethasone (DEX) decreased lipogenesis in both murine C2C12 and human LHC-NM2 myotubes. Inactivating p-Ser-79/218 of acetyl-CoA carboxylase 1/2 and activating p-Thr-172 of AMP-activated protein kinase were both increased after DEX treatment in C2C12 myotubes. In contrast, DEX increased β-oxidation. Selective 11β-HSD1 inhibition blocked the 11-dehydrocorticosterone (11DHC)-mediated decrease in lipogenic gene expression and increase in lipolytic gene expression. Lipogenic gene expression was decreased, whereas lipolytic and β-oxidative gene expression increased in corticosterone (CORT)- and 11DHC-treated wild-type mice and CORT (but not 11DHC)-treated 11β-HSD1(-/-) mice. Furthermore, CORT- and 11DHC-treated wild-type mice and CORT (but not 11DHC)-treated 11β-HSD1(-/-) mice had increased p-Ser-79/218 acetyl-CoA carboxylase 1/2, p-Thr-172 AMP-activated protein kinase and intramyocellular diacylglyceride content. In summary, we have shown that GCs have potent actions on intramyocellular lipid homeostasis by decreasing lipid storage, increasing lipid mobilization and utilization, and increasing diacylglyceride content. It is plausible that dysregulated intramyocellular lipid metabolism may underpin GC-induced insulin resistance of skeletal muscle.

Inherited forms of mineralocorticoid hypertension.

Purpose of reviewInherited forms of mineralocorticoid hypertension are a group of monogenic disorders that, although rare, have enlightened our understanding of normal physiology, and subsequent processes implicated in the pathogenesis of ‘essential’ hypertension. They often present in early life and can be a cause of major morbidity and mortality that can be effectively treated with simple but targeted pharmacological therapy. Interestingly, all the conditions centre on the regulation of sodium transport through its epithelial channel, either directly or through mediators that act via the mineralocorticoid receptor. Recent findingsIn recent years, molecular mechanisms of these conditions and their functional consequences have been elucidated. Diagnosis has been facilitated by plasma and urinary biomarkers. SummaryWe provide an overview and diagnostic approach to apparent mineralocorticoid excess, glucocorticoid remediable aldosteronism, familial hyperaldosteronism type 2, Liddles syndrome, Gordons syndrome, activating mutations of the mineralocorticoid receptor, generalized glucocorticoid resistance and hypertensive forms of congenital adrenal hyperplasia.