scholarly journals Impaired 11β-Hydroxysteroid Dehydrogenase Type 2 in Glucocorticoid-Resistant Patients

2019 ◽  
Vol 104 (11) ◽  
pp. 5205-5216 ◽  
Author(s):  
Géraldine Vitellius ◽  
Brigitte Delemer ◽  
Philippe Caron ◽  
Olivier Chabre ◽  
Jérôme Bouligand ◽  
...  
Keyword(s):  
Plasma Renin ◽  
Hydroxysteroid Dehydrogenase ◽  
Luciferase Reporter ◽  
Mrna Levels ◽  
Loss Of Function ◽  
Mcf7 Cells ◽  
Promoter Construct ◽  
Liquid Chromatography Tandem Mass ◽  
Apparent Mineralocorticoid Excess

Abstract Context Six patients carrying heterozygous loss-of-function mutations of glucocorticoid (GC) receptor (GR) presented with hypercortisolism, associated with low kalemia, low plasma renin, and aldosterone levels, with or without hypertension, suggesting a pseudohypermineralocorticism whose mechanisms remain unclear. We hypothesize that an impaired activity of the 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2; encoded by the HSD11B2 gene), catalyzing cortisol (F) inactivation, may account for an inappropriate activation of a renal mineralocorticoid signaling pathway in these GC-resistant patients. Objective We aim at studying the GR-mediated regulation of HSD11B2. Design The HSD11B2 promoter was subcloned and luciferase reporter assays evaluated GR-dependent HSD11B2 regulation, and 11β-HSD2 expression/activity was studied in human breast cancer MCF7 cells, endogenously expressing this enzyme. Results Transfection assays revealed that GR transactivated the long (2.1-kbp) HSD11B2 promoter construct, whereas a defective 501H GR mutant was unable to stimulate luciferase activity. GR-mediated transactivation of the HSD11B2 gene was inhibited by the GR antagonist RU486. A threefold increase in HSD11B2 mRNA levels was observed after dexamethasone (DXM) treatment of MCF7 cells, inhibited by RU486 or by actinomycin, supporting a GR-dependent transcription. Chromatin immunoprecipitation further demonstrated a DXM-dependent GR recruitment onto the HSD11B2 promoter. 11β-HSD2 activity, evaluated by the cortisone/F ratio, quantified by liquid chromatography/tandem mass spectrometry, was 10-fold higher in the supernatant of DXM-treated cells than controls, consistent with a GR-dependent stimulation of 11β-HSD2 catalytic activity. Conclusion Collectively, we demonstrate that 11β-HSD2 expression and activity are transcriptionally regulated by GR. In the context of GR haploinsufficiency, these findings provide evidence that defective GR signaling may account for apparent mineralocorticoid excess in GC-resistant patients.

scholarly journals Reduced Placental 11β-Hydroxysteroid Dehydrogenase Type 2 mRNA Levels in Human Pregnancies Complicated by Intrauterine Growth Restriction: An Analysis of Possible Mechanisms

2001 ◽  
Vol 86 (10) ◽  
pp. 4979-4983 ◽  
Author(s):  
C. L. McTernan ◽  
N. Draper ◽  
H. Nicholson ◽  
S. M. Chalder ◽  
P. Driver ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Intrauterine Growth Restriction ◽  
Subsequent Development ◽  
Hydroxysteroid Dehydrogenase ◽  
Underlying Mechanism ◽  
Growth Restriction ◽  
Mrna Levels ◽  
Intrauterine Growth ◽  
Apparent Mineralocorticoid Excess

11β-Hydroxysteroid dehydrogenase type 2 (11β-HSD2) inactivates cortisol to cortisone. In the placenta 11β-HSD2 activity is thought to protect the fetus from the deleterious effects of maternal glucocorticoids. Patients with apparent mineralocorticoid excess owing to mutations in the 11β-HSD2 gene invariably have reduced birth weight, and we have recently shown reduced placental 11β-HSD2 activity in pregnancies complicated by intrauterine growth restriction. This is reflected in the literature by evidence of hypercortisolemia in the fetal circulation of small babies. In this study we have determined the levels of placental 11β-HSD2 mRNA expression across normal gestation (n = 86 placentae) and in pregnancies complicated by intrauterine growth restriction (n = 19) and evaluated the underlying mechanism for any aberrant 11β-HSD2 mRNA expression in intrauterine growth restriction. 11β-HSD2 mRNA expression increased more than 50-fold across gestation, peaking at term. Placental 11β-HSD2 mRNA levels were significantly decreased in intrauterine growth restriction pregnancies when compared with gestationally matched, appropriately grown placentae [e.g. at termΔ Ct (11β-hydroxysteroid dehydrogenase type 2/18S) 12.8 ± 0.8 (mean ± se) vs. 10.2 ± 0.2, respectively, P < 0.001]. These differences were not attributable to changes in trophoblast mass in intrauterine growth restriction placentae, as assessed by parallel analyses of cytokeratin-8 mRNA expression. No mutations were found in the 11β-HSD2 gene in the intrauterine growth restriction cohort, and imprinting analysis revealed that the 11β-HSD2 gene was not imprinted. Although the underlying cause is unknown, 11β-HSD2 gene expression is reduced in intrauterine growth restriction pregnancies. These data highlight the important role of 11β-HSD2 in regulating fetal growth, a known factor in determining fetal morbidity but also the subsequent development of cardiovascular disease in adulthood.

scholarly journals CHOP and c-JUN up-regulate the mutant Z α1-antitrypsin, exacerbating its aggregation and liver proteotoxicity

2020 ◽  
Vol 295 (38) ◽  
pp. 13213-13223
Author(s):  
Sergio Attanasio ◽  
Rosa Ferriero ◽  
Gwladys Gernoux ◽  
Rossella De Cegli ◽  
Annamaria Carissimo ◽  
...  
Keyword(s):  
Liver Disease ◽  
Er Stress ◽  
Proteinase Inhibitors ◽  
Pediatric Population ◽  
Transcriptional Response ◽  
Luciferase Reporter ◽  
Mrna Levels ◽  
Primary Role ◽  
Loss Of Function ◽  
Human Livers

α1-Antitrypsin (AAT) encoded by the SERPINA1 gene is an acute-phase protein synthesized in the liver and secreted into the circulation. Its primary role is to protect lung tissue by inhibiting neutrophil elastase. The Z allele of SERPINA1 encodes a mutant AAT, named ATZ, that changes the protein structure and leads to its misfolding and polymerization, which cause endoplasmic reticulum (ER) stress and liver disease through a gain-of-function toxic mechanism. Hepatic retention of ATZ results in deficiency of one of the most important circulating proteinase inhibitors and predisposes to early-onset emphysema through a loss-of-function mechanism. The pathogenetic mechanisms underlying the liver disease are not completely understood. C/EBP-homologous protein (CHOP), a transcription factor induced by ER stress, was found among the most up-regulated genes in livers of PiZ mice that express ATZ and in human livers of patients homozygous for the Z allele. Compared with controls, juvenile PiZ/Chop−/− mice showed reduced hepatic ATZ and a transcriptional response indicative of decreased ER stress by RNA-Seq analysis. Livers of PiZ/Chop−/− mice also showed reduced SERPINA1 mRNA levels. By chromatin immunoprecipitations and luciferase reporter–based transfection assays, CHOP was found to up-regulate SERPINA1 cooperating with c-JUN, which was previously shown to up-regulate SERPINA1, thus aggravating hepatic accumulation of ATZ. Increased CHOP levels were detected in diseased livers of children homozygous for the Z allele. In summary, CHOP and c-JUN up-regulate SERPINA1 transcription and play an important role in hepatic disease by increasing the burden of proteotoxic ATZ, particularly in the pediatric population.

scholarly journals A urine-concentrating defect in 11β-hydroxysteroid dehydrogenase type 2 null mice

2012 ◽  
Vol 303 (4) ◽  
pp. F494-F502 ◽  
Author(s):  
Louise C. Evans ◽  
Dawn E. Livingstone ◽  
Christopher J. Kenyon ◽  
Maurits A. Jansen ◽  
James W. Dear ◽  
...  
Keyword(s):  
Water Deprivation ◽  
Renal Medulla ◽  
Hydroxysteroid Dehydrogenase ◽  
Renal Structure ◽  
Apparent Mineralocorticoid Excess ◽  
Natriuretic Effect ◽  
V2 Receptor ◽  
Response To Water ◽  
Concentrating Defect

In aldosterone target tissues, 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2) is coexpressed with mineralocorticoid receptors (MR) and protects the receptor from activation by glucocorticoids. Null mutations in the encoding gene, HSD11B2, cause apparent mineralocorticoid excess, in which hypertension is thought to reflect volume expansion secondary to sodium retention. Hsd11b2−/− mice are indeed hypertensive, but impaired natriuretic capacity is associated with significant volume contraction, suggestive of a urine concentrating defect. Water turnover and the urine concentrating response to a 24-h water deprivation challenge were therefore assessed in Hsd11b2 −/− mice and controls. Hsd11b2 −/− mice have a severe and progressive polyuric/polydipsic phenotype. In younger mice (∼2 mo of age), polyuria was associated with decreased abundance of aqp2 and aqp3 mRNA. The expression of other genes involved in water transport ( aqp4, slc14a2, and slc12a2) was not changed. The kidney was structurally normal, and the concentrating response to water deprivation was intact. In older Hsd11b2 −/− mice (>6 mo), polyuria was associated with a severe atrophy of the renal medulla and downregulation of aqp2, aqp3, aqp4, slc14a2, and slc12a2. The concentrating response to water deprivation was impaired, and the natriuretic effect of the loop diuretic bumetanide was lost. In older Hsd11b2 −/− mice, the V2 receptor agonist desmopressin did not restore full urine concentrating capacity. We find that Hsd11b2 −/− mice develop nephrogenic diabetes insipidus. Gross changes to renal structure are observed, but these were probably secondary to sustained polyuria, rather than of developmental origin.

Apparent mineralocorticoid excess caused by a novel mutation in 11β-hydroxysteroid dehydrogenase type 2 gene

2017 ◽  
Vol 35 (3) ◽  
pp. 647-650 ◽  
Author(s):  
Yue Wang ◽  
Linqiang Ma ◽  
Xiaoyu Shu ◽  
Jiayu Li ◽  
Jinbo Hu ◽  
...  
Keyword(s):  
Novel Mutation ◽  
Hydroxysteroid Dehydrogenase ◽  
Apparent Mineralocorticoid Excess

scholarly journals Proliferative responses to altered 17β-hydroxysteroid dehydrogenase (17HSD) type 2 expression in human breast cancer cells are dependent on endogenous expression of 17HSD type 1 and the oestradiol receptors

2006 ◽  
Vol 13 (3) ◽  
pp. 875-884 ◽  
Author(s):  
A Jansson ◽  
C Gunnarsson ◽  
O Stål
Keyword(s):  
Breast Cancer ◽  
Epithelial Cells ◽  
Cell Lines ◽  
Hydroxysteroid Dehydrogenase ◽  
S Phase ◽  
Phase Fraction ◽  
Mcf7 Cells ◽  
Endogenous Expression

The primary source of oestrogen in premenopausal women is the ovary but, after menopause, oestrogen biosynthesis in peripheral tissue is the exclusive site of formation. An enzyme group that affects the availability of active oestrogens is the 17β-hydroxysteroid dehydrogenase (17HSD) family. In breast cancer, 17HSD type 1 and type 2 have been mostly investigated and seem to be the principal 17HSD enzymes involved thus far. The question whether 17HSD type 1 or type 2 is of greatest importance in breast tumour development is still not clear. The aim of this study was to investigate how the loss of 17HSD type 2 expression, using siRNA in the non-tumour breast epithelial cells HMEC (human mammal epithelial cells) and MCF10A, and gain of 17HSD type 2 expression, using transient transfection in the breast cancer derived cell lines MCF7 and T47D, affect oestradiol conversion and proliferation rate measured as S-phase fraction. We further investigated how this was related to the endogenous expression of 17HSD type 1 and oestradiol receptors in the examined cell lines. The oestradiol level in the medium changed significantly in the MCF7 transfected cells and the siRNA-treated HMEC cells, but not in T47D or MCF10A. The S-phase fraction decreased in the 17HSD type 2-transfected MCF7 cells and the siRNA-treated HMEC cells. The results seemed to be dependent on the endogenous expression of 17HSD type 1 and the oestradiol receptors. In conclusion, we found that high or low levels of 17HSD type 2 affected the oestradiol concentration significantly. However, the response was dependent on the endogenous expression of 17HSD type 1. Expression of 17HSD type 1 seems to be dominant to 17HSD type 2. Therefore, it may be important to investigate a ratio between 17HSD type 1 and 17HSD type 2.

scholarly journals Activation of Mineralocorticoid Receptors by Exogenous Glucocorticoids and the Development of Cardiovascular Inflammatory Responses in Adrenalectomized Rats

Endocrinology ◽  
2010 ◽  
Vol 151 (6) ◽  
pp. 2622-2628 ◽  
Author(s):  
Morag J. Young ◽  
James Morgan ◽  
Kim Brolin ◽  
Peter J. Fuller ◽  
John W. Funder
Keyword(s):  
Cardiac Fibrosis ◽  
Inflammatory Responses ◽  
Salt Intake ◽  
Hydroxysteroid Dehydrogenase ◽  
Tissue Growth ◽  
Mrna Levels ◽  
Sprague Dawley ◽  
High Salt Intake ◽  
Adrenalectomized Rats

Activation of the mineralocorticoid receptor (MR) in the context of a high salt intake produces cardiovascular inflammation plus cardiac fibrosis and failure. Inactivation of vascular 11β-hydroxysteroid dehydrogenase type 2 activity in intact animals by carbenoxolone (CBX) produces a similar pathology, presumably reflecting coronary vascular MR activation by endogenous glucocorticoids. To test this hypothesis, we have used adrenalectomized rats, without endogenous corticosteroids, and examined the consequences of corticosterone (CORT) replacement on a series of cardiovascular disease parameters. Uninephrectomized adrenalectomized Sprague Dawley rats given 1% NaCl/0.3% KCl to drink were treated for 8 d as follows: control; 20 mg deoxycorticosterone (DOC); 2 mg/d CORT; 2.5 mg/d CBX; CORT plus CBX (CORT/CBX); and CORT/CBX plus 100 mg/kg·d eplerenone. Markers of cardiac oxidative stress (p22phox and NOX4 mRNA) were up-regulated in the DOC and CORT/CBX groups; in contrast, inflammatory cell infiltration was increased and endothelial nitric oxide synthase down-regulated by CORT as well as by DOC and CORT/CBX. In the kidney, connective tissue growth factor mRNA levels were increased by DOC and CORT/CBX; in contrast, DOC had no effect on mRNA levels for channel inducing factor or endothelin 3, which were elevated only by CORT/CBX. All changes noted were reversed by eplerenone. Rats given 10-fold lower CORT (0.2 mg/d) with or without CBX showed no change in any parameter. These results suggest that there exist distinct but overlapping ligand-specific MR-mediated tissue responses to a classic mineralocorticoid (DOC) and to the glucocorticoid CORT, in the presence and absence of CBX to block vascular 11β-hydroxysteroid dehydrogenase type 2.

Abstract 551: Deficiency of Hepatic Nuclear Factor 4 Alpha Results in Impaired Metabolism of Endogenous Methylarginines and Beta-aminoisobutiric Acid - A Novel Mechanism of Cardiovascular Complications in Patients With Type 2 Diabetes?

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Dmitrii V Burdin ◽  
Alexey A Kolobov ◽  
Anton V Demyanov ◽  
Alexey A Soshnev ◽  
Chad N Broker ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Binding Site ◽  
Promoter Region ◽  
Core Promoter ◽  
Luciferase Reporter ◽  
Diabetic Patients ◽  
Mrna Levels ◽  
Nuclear Factor ◽  
Wild Type

Introduction: Alanine-glyoxylate aminotransferase 2 (AGXT2) is the only known enzyme capable of degradation of all three endogenous methylarginines, which serve as markers and potentially mediators of cardiovascular disease. Recent studies also suggest that AGXT2 and its alternative substrate beta-aminoisobutyric acid (BAIB) play important role in lipid metabolism. The predicted core promoter region of mammalian AGXT2 promoter contains a highly conserved putative binding site for hepatic nuclear factor 4 alpha (HNF4A). Patients with severe deficiency in HNF4a develop maturity onset diabetes of young 1. Furthermore, polymorphisms of HNF4A are associated with increased risk of diabetes type 2. The aim of this study was to test the hypothesis that HNF4A is a major regulator of AGXT2 expression and activity. Methods and results: We demonstrated direct binding of HNF4A to the Agxt2 promoter region in hepatic cell line Hepa 1-6 using chromatin immunoprecipitation assays. Then we showed that mutations of the predicted HNF4A binding site in the Agxt2 core promoter result in up to 80% decrease in the promoter activity as assessed by luciferase reporter assays (p<0.001). We used siRNA-mediated knockdown of HNF4A to determine whether this factor is required for basal Agxt2 expression in Hepa 1-6 cells. Knockdown of HNF4A led to almost 50% reduction in Agxt2 mRNA levels compared to controls (p<0.01). We took advantage of the previously characterized inducible liver-specific Hnf4a knockout (KO) mice to determine whether HNF4A regulates Agxt2 expression in vivo and showed a 90% (p<0.001) decrease in liver Agxt2 expression and a 85% (p<0.01) decrease in liver AGXT2 activity towards methylarginines in Hnf4a KO mice compared with the wild-type littermates. Finaly, on a functional level, Hnf4a KO mice had significant amounts of BAIB present in plasma, whereas BAIB was not detectable in the plasma of the wild-type littermates. Conclusions: In our study we identified HNF4A as the major regulator of Agxt2 gene expression. This finding suggests that diabetic patients with HNF4A deficiency might have a unique mechanism for development of cardiovascular complication via AGXT2-dependent impairment of lipid metabolism and methylarginines-mediated vascular dysfunction.

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