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M Quinkler, W Oelkers and S Diederich

11beta-Hydroxysteroid dehydrogenases (11beta-HSD) are microsomal enzymes that catalyze the conversion of active glucocorticoids (GC) to their inactive 11-dehydro products and vice versa. Two isoenzymes of 11beta-HSD have been characterized and cloned in human tissues. The tissue-specific metabolism of GC by these enzymes is important for mineralocorticoid (MC) and GC receptor occupancy and seems to play a crucial role in the pathogenesis of diseases such as apparent MC excess syndrome, and may play roles in hypertension, obesity and impaired hepatic glucose homeostasis. This article reviews the literature and examines the role and importance of 11beta-HSD in humans.

Free access

S Diederich, C Grossmann, B Hanke, M Quinkler, M Herrmann, V Bahr and W Oelkers

OBJECTIVE: Selective inhibitors of 11beta-hydroxysteroid-dehydrogenase type I may be of therapeutical interest for two reasons: i) 9alpha-Fluorinated 11-dehydrosteroids like 11-dehydro-dexamethasone (DH-D) are rapidly activated by human kidney 11beta-hydroxysteroid-dehydrogenase type II (11beta-HSD-II) to dexamethasone (D). If the same reaction by hepatic 11beta-HSD-I could be selectively inhibited, DH-D could be used for selective renal immunosuppressive therapy. ii) Reduction of cortisone to cortisol in the liver may increase insulin resistance in type 2 diabetes mellitus, and inhibition of the enzyme may lead to a decrease in gluconeogenesis. Therefore, we characterized the metabolism of DH-D by human hepatic 11beta-HSD-I and tried to find a selective inhibitor of this isoenzyme. METHODS: For kinetic analysis of 11beta-HSD-I, we used microsomes prepared from unaffected parts of liver segments, resected because of hepatocarcinoma or metastatic disease. For inhibition experiments, we also tested 11beta-HSD-II activity with human kidney cortex microsomes. The inhibitory potency of several compounds was evaluated for oxidation and reduction in concentrations from 10(-9) to 10(-5)mol/l. RESULTS: Whereas D was not oxidized by human liver microsomes at all, cortisol was oxidized to cortisone with a maximum velocity (V(max)) of 95pmol/mg per min. The reduction of DH-D to D (V(max)=742pmol/mg per min, Michaelis--Menten constant (K(m))=1.6 micromol/l) was faster than that of cortisone to cortisol (V(max)=187pmol/mg per min). All reactions tested in liver microsomes showed the characteristics of 11beta-HSD-I: K(m) values in the micromolar range, preferred cosubstrate NADP(H), no product inhibition. Of the substances tested for inhibition of 11beta-HSD-I and -II, chenodeoxycholic acid was the only one that selectively inhibited 11beta-HSD-I (IC(50) for reduction: 2.8x10(-6)mol/l, IC(50) for oxidation: 4.4x10(-6)mol/l), whereas ketoconazole preferentially inhibited oxidation and reduction reactions catalyzed by 11beta-HSD-II. Metyrapone, which is reduced to metyrapol by hepatic 11beta-HSD-I, inhibited steroid reductase activity of 11beta-HSD-I and -II and oxidative activity of 11beta-HSD-II. These findings can be explained by substrate competition for reductase reactions and by product inhibition of the oxidation, which is a well-known characteristic of 11beta-HSD-II. CONCLUSIONS: Our in vitro results may offer a new concept for renal glucocorticoid targeting. Oral administration of small amounts of DH-D (low substrate affinity for 11beta-HSD-I) in combination with chenodeoxycholic acid (selective inhibition of 11beta-HSD-I) may prevent hepatic first pass reduction of DH-D, thus allowing selective activation of DH-D to D by the high affinity 11beta-HSD-II in the kidney. Moreover, selective inhibitors of the hepatic 11beta-HSD-I, like chenodeoxycholic acid, may become useful in the therapy of patients with hepatic insulin resistance including diabetes mellitus type II, because cortisol enhances gluconeogenesis.

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S Diederich, M Quinkler, K Miller, P Heilmann, M Schöneshöfer and W Oelkers

Diederich S, Quinkler M, Miller K, Heilmann P, Schöneshöfer M, Oelkers W. Human kidney 11βhydroxysteroid dehydrogenase: regulation by adrenocorticotropin? Eur J Endocrinol 1996;134:301–7. ISSN 0804–4643

In ectopic adrenocorticotropin (ACTH) syndrome (EAS) with higher ACTH levels than in pituitary Cushing's syndrome and during ACTH infusion, the ratio of cortisol to cortisone in plasma and urine is increased, suggesting inhibition of renal 11β-hydroxysteroid dehydrogenase (11β-HSD) by ACTH or by ACTH-dependent steroids. Measuring the conversion of cortisol to cortisone by human kidney slices under different conditions, we tested the possibility of 11β-HSD regulation by ACTH and corticosteroids. Slices prepared from unaffected parts of kidneys removed because of renal cell carcinoma were incubated with unlabeled or labeled cortisol, and cortisol and cortisone were quantitated after HPLC separation by UV or radioactive detection. The 11β-HSD activity was not influenced by incubation with increasing concentrations (10−12–10−9 mol/l) of ACTH (1–24 or 1–39) for 1 h. Among 12 ACTH-dependent steroids tested (10−9–10−6 mol/l), only corticosterone (IC50 = 2 × 10−7 mol/l), 18-OH-corticosterone and 11βOH-androstenedione showed a significant dose-dependent inhibition of 11β-HSD activity. The percentage conversion rate of cortisol to cortisone was concentration dependent over the whole range of cortisol concentrations tested (10−8–10−5 mol/l). A direct inhibitory effect of ACTH on 11β-HSD is, therefore, unlikely. The only steroids inhibiting the conversion of cortisol to cortisone are natural substrates for 11β-HSD Kinetic studies show a saturation of the enzyme at high cortisol concentrations. Thus, the reduced percentage renal cortisol inactivation in EAS seems to be due mainly to overload of the enzyme with endogenous substrates (cortisol, corticosterone and others) rather than to direct inhibition of 11β-HSD by ACTH or ACTHdependent steroids, not being substrates of 11β-HSD.

S Diederich, Department of Endocrinology, Klinikum Benjamin Franklin, Freie Universität Berlin, Hindenburgdamm 30, 12200 Berlin, Germany

Open access

C T Fuss, M Treitl, N Rayes, P Podrabsky, W K Fenske, D A Heinrich, M Reincke, T-O Petersen, M Fassnacht, M Quinkler, R Kickuth and S Hahner

Objective

Adrenal vein sampling (AVS) represents the current diagnostic standard for subtype differentiation in primary aldosteronism (PA). However, AVS has its drawbacks. It is invasive, expensive, requires an experienced interventional radiologist and comes with radiation exposure. However, exact radiation exposure of patients undergoing AVS has never been examined.

Design and methods

We retrospectively analyzed radiation exposure of 656 AVS performed between 1999 and 2017 at four university hospitals. The primary outcomes were dose area product (DAP) and fluoroscopy time (FT). Consecutively the effective dose (ED) was approximately calculated.

Results

Median DAP was found to be 32.5 Gy*cm2 (0.3–3181) and FT 18 min (0.3–184). The calculated ED was 6.4 mSv (0.1–636). Remarkably, values between participating centers highly varied: Median DAP ranged from 16 to 147 Gy*cm2, FT from 16 to 27 min, and ED from 3.2 to 29 mSv. As main reason for this variation, differences regarding AVS protocols between centers could be identified, such as number of sampling locations, frames per second and the use of digital subtraction angiographies.

Conclusion

This first systematic assessment of radiation exposure in AVS not only shows fairly high values for patients, but also states notable differences among the centers. Thus, we not only recommend taking into account the risk of radiation exposure, when referring patients to undergo AVS, but also to establish improved standard operating procedures to prevent unnecessary radiation exposure.

Free access

M Quinkler, B Meyer, C Bumke-Vogt, C Grossmann, U Gruber, W Oelkers, S Diederich and V Bahr

OBJECTIVE: Progesterone binds to the human mineralocorticoid receptor (hMR) with nearly the same affinity as do aldosterone and cortisol, but confers only low agonistic activity. It is still unclear how aldosterone can act as a mineralocorticoid in situations with high progesterone concentrations, e.g. pregnancy. One mechanism could be conversion of progesterone to inactive compounds in hMR target tissues. DESIGN: We analyzed the agonist and antagonist activities of 16 progesterone metabolites by their binding characteristics for hMR as well as functional studies assessing transactivation. METHODS: We studied binding affinity using hMR expressed in a T7-coupled rabbit reticulocyte lysate system. We used co-transfection of an hMR expression vector together with a luciferase reporter gene in CV-1 cells to investigate agonistic and antagonistic properties. RESULTS: Progesterone and 11beta-OH-progesterone (11beta-OH-P) showed a slightly higher binding affinity than cortisol, deoxycorticosterone and aldosterone. 20alpha-dihydro(DH)-P, 5alpha-DH-P and 17alpha-OH-P had a 3- to 10-fold lower binding potency. All other progesterone metabolites showed a weak affinity for hMR. 20alpha-DH-P exhibited the strongest agonistic potency among the metabolites tested, reaching 11.5% of aldosterone transactivation. The agonistic activity of 11beta-OH-P, 11alpha-OH-P and 17alpha-OH-P was 9, 5.1 and 4.1% respectively. At a concentration of 100 nmol/l, progesterone, 17alpha-OH-P and 20alpha-DH-P inhibit nearly 75, 40 and 35% of the transactivation by aldosterone respectively. All other progesterone metabolites tested demonstrate weaker affinity, and agonistic and antagonistic potency. CONCLUSIONS: The binding affinity for hMR and the agonistic and antagonistic activity diminish with increasing reduction of the progesterone molecule at C20, C17 and at ring A. We assume that progesterone metabolism to these compounds is a possible protective mechanism for hMR. 17alpha-OH-P is a strong hMR antagonist and could exacerbate mineralocorticoid deficiency in patients with congenital adrenal hyperplasia.

Free access

Susanna Wiegand, Anna Richardt, Thomas Remer, Stefan A Wudy, Jeremy W Tomlinson, Beverly Hughes, Annette Grüters, Paul M Stewart, Christian J Strasburger and Marcus Quinkler

Objective: The incidence of childhood obesity and type 2 diabetes has reached epidemic proportions. Glucocorticoid excess causes central obesity and diabetes mellitus as seen in Cushing’s syndrome. The 11β-hydroxysteroid dehydrogenase type 1 enzyme (11β-HSD1) regenerates active cortisol from inactive cortisone. Altered 11β-HSD1 may cause tissue-specific Cushing’s syndrome with central obesity and impaired glucose homeostasis.

Design, patients, and methods: Clinical and laboratory characteristics, and anthropometric measurements were determined in 15 male and 6 female obese pubertal children (aged 12–18 years, Tanner stages 2–5). In addition, analyses of 24-h excretion rates of glucocorticoids were also performed in 21 age-, sex-, and pubertal stage-matched non-obese children using gas chromatographic–mass spectrometric (GC–MS) analysis.

Results: 11β-HSD1 activity (urinary tetrahydrocortisol (THF) + 5α-THF/tetrahydrocortisone (THE) ratio) was lower in obese when compared with non-obese boys. In addition, obese children had a higher total cortisol metabolite excretion than non-obese children. 11β-HSD1 activity was significantly related to age in lean and obese children. Standard deviation score (SDS)-body mass index did not correlate with 11β-HSD1 activity, or with total cortisol metabolite excretion within each group. In obese children, 11β-HSD1 activity and total cortisol metabolite excretion showed no correlation to waist-to-hip ratio, fat mass (percentage of body mass), or the homeostasis model assessment of insulin resistance index.

Conclusions: In conclusion, our findings strongly suggest that 11β-HSD1 activity increases with age, and is reduced in obese boys. In addition, obese children have a higher total cortisol metabolites excretion suggesting a stimulated hypothalamus–pituitary–adrenal axis.

Free access

Marcus Quinkler, Daniel Zehnder, Julia Lepenies, Massimiliano D Petrelli, Jasbir S Moore, Susan V Hughes, Paul Cockwell, Martin Hewison and Paul M Stewart

Objective: Renal 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) enables selective access of aldosterone to the mineralocorticoid receptor (MR). Impaired 11β-HSD2 activity has been suggested in patients with hypertension as well as in patients with renal disease, where it may contribute to sodium retention, oedema and hypertension. To date, these studies have relied upon urinary cortisol (F) metabolite levels as surrogate markers of renal 11β-HSD2 activity.

Methods: We have directly analysed renal 11β-HSD2 mRNA expression in 95 patients undergoing kidney biopsy using TaqMan real-time PCR. Serum and 24-h urine samples were used to document underlying renal function and endocrine parameters. Urinary F and cortisone (E) metabolites were analysed using gas chromatography/mass spectrometry.

Results: Expression of 11β-HSD2 did not correlate with blood pressure or urinary Na/K ratio, but a significant positive correlation with creatinine clearance was observed (r = 0.284; P < 0.01). Immunofluorescence and confocal laser microscopy confirmed decreased 11β-HSD2 expression in patients with impaired renal function. For the first time, we showed that 11β-HSD2 mRNA expression correlated negatively with the urinary free (UF) F/E (UFF/UFE) ratio (r = 0.276; P < 0.05) as well as with the urinary tetrahydrocortisol + 5α-tetrahydrocortisol/tetrahydrocortisone ((THF + αTHF)/THE) ratio (r = 0.256; P < 0.05). No difference in 11β-HSD2 mRNA expression or in the UFF/UFE ratio was found between groups with no proteinuria, microalbuminuria, moderate or severe proteinuria. In contrast, the urinary (THF + αTHF)/THE ratio increased significantly (P < 0.05) in patients with severe albuminuria, suggesting increased hepatic 11β-HSD1 in those patients.

Conclusions: These data suggest that renal 11β-HSD2 expression may be represented only marginally better, if at all, by the UFF/UFE than by the (THF + αTHF)/THE ratio. Reduced renal 11β-HSD2 expression may lead to occupancy of the MR by glucocorticoids such as cortisol and may contribute to the increased sodium retention seen in patients with impaired renal function.

Free access

Britta Heinze, Leonie J M Herrmann, Martin Fassnacht, Cristina L Ronchi, Holger S Willenberg, Marcus Quinkler, Nicole Reisch, Martina Zink, Bruno Allolio and Stefanie Hahner

Context

The Li–Fraumeni tumor syndrome is strongly associated with adrenocortical carcinoma (ACC) and is caused by germline mutations in TP53 in 70% of cases. Also, TP53 polymorphisms have been shown to influence both cancer risk and clinical outcome in several tumor entities. We, therefore, investigated TP53 polymorphisms in a cohort of adult patients with ACC.

Objective

Evaluation of the role of TP53 polymorphisms in adult patients with ACC.

Subjects and methods

Peripheral blood for DNA extraction was collected from 72 ACC patients. Polymorphism analysis was carried out by amplification and sequencing of exons and adjacent intron sections of TP53. Results were correlated with clinical data and the distribution of the polymorphisms was compared with published Caucasian control groups.

Results

Compared with control groups, genotype frequencies of analyzed TP53 polymorphisms among ACC patients were significantly different in three out of four polymorphisms: IVS2+38G>C (G/G, P=0.0248), IVS3ins16 (NoIns/NoIns, P<0.0001; NoIns/Ins, P<0.0001), and IVS6+62A>G (G/G, P<0.0001; G/A, P<0.0001). Overall, the survival of ACC patients, which harbored at least one of the less frequent genotype variants of four analyzed polymorphisms (n=23), was significantly inferior (median survival: 81.0 months in patients with the common homozygous genotypes vs 20.0 months in patients with the less frequent genotypes, HR 2.56, 95% CI 1.66–7.07; P=0.001). These results were confirmed by multivariable regression analysis (HR 2.84, 95% CI 1.52–7.17; P=0.037).

Conclusion

Some TP53 polymorphisms seem to influence overall survival in ACC patients. This effect was observed for a combination of polymorphic changes rather than for single polymorphisms.

Free access

Guido Di Dalmazi, Marcus Quinkler, Timo Deutschbein, Cornelia Prehn, Nada Rayes, Matthias Kroiss, Christina M Berr, Günter Stalla, Martin Fassnacht, Jerzy Adamski, Martin Reincke and Felix Beuschlein

Objective

Endogenous hypercortisolism is a chronic condition associated with severe metabolic disturbances and cardiovascular sequela. The aim of this study was to characterize metabolic alterations in patients with different degrees of hypercortisolism by mass-spectrometry-based targeted plasma metabolomic profiling and correlate the metabolomic profile with clinical and hormonal data.

Design

Cross-sectional study.

Methods

Subjects (n = 149) were classified according to clinical and hormonal characteristics: Cushing’s syndrome (n = 46), adrenocortical adenomas with autonomous cortisol secretion (n = 31) or without hypercortisolism (n = 27). Subjects with suspicion of hypercortisolism, but normal hormonal/imaging testing, served as controls (n = 42). Clinical and hormonal data were retrieved for all patients and targeted metabolomic profiling was performed.

Results

Patients with hypercortisolism showed lower levels of short-/medium-chain acylcarnitines and branched-chain and aromatic amino acids, but higher polyamines levels, in comparison to controls. These alterations were confirmed after excluding diabetic patients. Regression models showed significant correlation between cortisol after dexamethasone suppression test (DST) and 31 metabolites, independently of confounding/contributing factors. Among those, histidine and spermidine were also significantly associated with catabolic signs and symptoms of hypercortisolism. According to an discriminant analysis, the panel of metabolites was able to correctly classify subjects into the main diagnostic categories and to distinguish between subjects with/without altered post-DST cortisol and with/without diabetes in >80% of the cases.

Conclusions

Metabolomic profiling revealed alterations of intermediate metabolism independently associated with the severity of hypercortisolism, consistent with disturbed protein synthesis/catabolism and incomplete β-oxidation, providing evidence for the occurrence of metabolic inflexibility in hypercortisolism.

Restricted access

U J Knappe, D Petroff, M Quinkler, S M Schmid, C Schöfl, J Schopohl, M R Stieg, A Tönjes and the participants of the German Acromegaly Registry

Background

If biochemical control of acromegaly is not achieved by operation and medication, radiotherapy may be indicated.

Objective

To describe fractionated radiotherapy (FRT) and stereotactic radiosurgery (SRS) regarding excess of IGF-1 and pituitary function.

Design and methods

A retrospective analysis of 352 patients (4126 patient-years) from the German Acromegaly Registry was performed. Follow-up was 1.0–45.1 years after radiotherapy. Therapeutic success was defined by low or normal IGF-1 according to center-specific reference ranges without (= remission) or on (= controlled disease) suppressive medication.

Results

Time between radiotherapy and last follow-up was 13.0 ± 8.2 years for FRT (n = 233) and 8.9 ± 5.0 years for SRS (n = 119, P < 0.001). Median (IQR) basal growth hormone before radiotherapy was 6.3 (2.9–16.2) ng/mL for FRT and 3.5 (1.8–6.9) ng/mL for SRS (P < 0.001). Mean time in uncontrolled state was 3.0 years after FRT and 2.1 years after SRS (95% CI for the difference is 0.1 to 1.6 years, P = 0.021). The 10-year calculated remission rate was 48% for FRT and 52% for SRS (95% CI for the difference is −18 to 26% age points, P = 0.74) and the respective controlled disease rate was 23 and 26%. The odds ratio for adrenocorticotropic or thyreotropic insufficiency was 0.54 (95% CI: 0.30–1.00, P = 0.049) in SRS compared to FRT patients.

Conclusion

Both after FRT and SRS about 75% of patients with acromegaly are in remission or controlled after 10 years. A slightly faster achievement of target values was observed after SRS. The rate of pituitary insufficiency in FRT patients is significantly higher.