Glucocorticoid Receptor Variants Research Articles

Genetic glucocorticoid receptor variants differ between ethnic groups but do not explain variation in age of diabetes onset, metabolic and inflammation parameters in patients with type 2 diabetes.

The effect of excess glucocorticoid receptor (GR) stimulation through glucocorticoid medication or cortisol on glucose metabolism is well established. There are genetic GR variants that result in increased or decreased GR stimulation. We aimed to determine the prevalence of genetic GR variants in different ethnic groups in a cohort of patients with type 2 diabetes, and we aimed to determine their association with age of diabetes onset and metabolic and inflammation parameters. A cross-sectional analysis was performed in a multiethnic cohort (n = 602) of patients with established type 2 diabetes. Polymorphisms in the GR gene that have previously been associated with altered glucocorticoid sensitivity (TthIIII, ER22/23EK N363S, BclI and 9β) were determined and combined into 6 haplotypes. Associations with age of diabetes onset, HbA1c, hs-CRP and lipid values were evaluated in multivariate regression models. The prevalence of the SNPs of N363S and BclI was higher in Dutch than in non-Dutch patients. We observed a lower prevalence of the SNP 9β in Dutch, South(East) Asian and Black African patients versus Turkish and Moroccan patients. We did not detect an association between SNPs and diabetes age of onset or metabolic parameters. We only found a trend for lower age of onset and higher HbA1c in patients with 1 or 2 copies of haplotype 3 (TthIIII + 9β). The prevalence of genetic GR variants differs between patients of different ethnic origins. We did not find a clear association between genetic GR variants and age of diabetes onset or metabolic and inflammation parameters. This indicates that the clinical relevance of GR variants in patients with established type 2 diabetes is limited.

Adrenalectomy Improves Blood Pressure and Metabolic Control in Patients With Possible Autonomous Cortisol Secretion: Results of a RCT.

ObjectiveThe best approach to patients with adrenal incidentaloma (AI) and possible autonomous cortisol secretion (PACS) is debated. The aim of this study was to assess the metabolic effect of adrenalectomy in AI patients with PACS in relation to cortisol secretion parameters, peripheral activation, and glucocorticoid sensitivity.DesignThis is a multicenter randomized study (NCT number: NCT04860180).MethodsSixty-two AI outpatients (40–75 years) with AI >1 cm and cortisol after overnight dexamethasone suppression test (F-1mgDST) between 50 and 138 nmol/L were randomized to adrenalectomy (Arm A) or a conservative approach (Arm B). Fifty-five patients completed the 6-month follow-up, 25 patients in Arm A (17 female patients, aged 62.5 ± 10.4 years) and 30 patients in Arm B (24 female patients, 66.1 ± 9.1 years). Plasma adrenocorticotroph hormone (ACTH), 24-h urinary free cortisol, 24-h urinary free cortisone, F-1mgDST, glucose, lipids, glycated hemoglobin (HbA1c) levels, blood pressure (BP), body weight, and treatment variations were assessed. The 24-h urinary free cortisol/cortisone ratio (an 11-beta hydroxysteroid dehydrogenase type 2 activity marker), BclI, and the N363S variants of glucocorticoid receptor (GR) polymorphisms were also evaluated.ResultsBP control improved in 68% and 13% of the subjects in Arm A and Arm B, respectively (p = 0.001), and the glycometabolic control improved in 28% and 3.3% of the subjects in Arm A and Arm B patients, respectively (p = 0.02). Arm A subjects more rarely showed the BP and/or glycometabolic control worsening than Arm B patients (12% and 40%, respectively, p = 0.03). The surgical approach was independently associated with BP amelioration (OR 3.0, 95% CI 3.8–108.3, p < 0.001) but not with age, F-1mgDST levels, BMI, and hypertension and diabetes mellitus presence at baseline. The 24-h urinary free cortisol/cortisone ratio and the presence of sensitizing GR polymorphisms were not associated with the surgical outcome. The receiver operating characteristic (ROC) curve analysis showed that the BP control amelioration was associated with F-1mgDST [area under the curve (AUC), 0.82 ± 0.09 p = 0.012]. The F-1mgDST cutoff with the best compromise in predicting the BP amelioration was set at 75 nmol/L (sensitivity 77%, specificity 75%).ConclusionsAI patients with PACS benefit from surgery in terms of BP and glycometabolic control.

Glucocorticoid resistance conferring mutation in the C-terminus of GR alters the receptor conformational dynamics

The glucocorticoid receptor is a key regulator of essential physiological processes, which under the control of the Hsp90 chaperone machinery, binds to steroid hormones and steroid-like molecules and in a rather complicated and elusive response, regulates a set of glucocorticoid responsive genes. We here examine a human glucocorticoid receptor variant, harboring a point mutation in the last C-terminal residues, L773P, that was associated to Primary Generalized Glucocorticoid Resistance, a condition originating from decreased affinity to hormone, impairing one or multiple aspects of GR action. Using in vitro and in silico methods, we assign the conformational consequences of this mutation to particular GR elements and report on the altered receptor properties regarding its binding to dexamethasone, a NCOA-2 coactivator-derived peptide, DNA, and importantly, its interaction with the chaperone machinery of Hsp90.

A Novel Human Glucocorticoid Receptor Variant, G459V, is Hyperactive in Response to Steroids.

A potential cause of the variable response to injury and sepsis is the variability of a patient's human glucocorticoid receptor (hGR) profile. To identify hGR variants, blood samples were collected on admission and biweekly thereafter from hospitalized patients who sustained at least a 20% total body surface area burn injury. A hyperactive G1376T single-nucleotide polymorphism (SNP) isoform was identified. This SNP led to a single amino acid change of glutamine to valine at site 459, "G459V," in the DNA-binding domain. The isoform's activity was tested in a reporter assay after treatment with steroids, the hGR antagonist RU486 (mifepristone) alone, or RU486 followed by steroids. When treated with hydrocortisone, the hGR G459V isoform had a hyperactive response; its activity was over 30 times greater than the reference hGRα. Unexpectedly, G459V had significantly increased activity when treated with the hGR antagonist RU486. With the combination of both RU486 and hydrocortisone, G459V activity was repressed, but greater than that of RU486 alone. Finally, when hGRα was cotransfected with G459V to simulate isoform interaction, the activity was closer to that of the hGRα profile than the G459V isoform. The unique activity of the G459V isoform shows that some variants of hGR have the potential to alter a person's response to stress and steroid treatment and may be a factor as to why mitigating the clinical response to sepsis and other stressors has been so elusive.

Functional Characterization of Glucocorticoid Receptor Variants Is Required to Avoid Misinterpretation of NGS Data.

Recent advances in genetic analysis technologies such as next-generation sequencing (NGS) have considerably increased the incidental discovery of genetic abnormalities. Six heterozygous missense mutations of the human glucocorticoid receptor (GR; encoded by the NR3C1 gene) have been identified in the context of genetic screening of endocrine pathologies. GR, a nuclear receptor, hormone-induced transcription factor, is involved in many physiological processes. Nevertheless, the pathogenic significance of incidentally discovered mutations remains obscure. The aim of this work was to characterize these variants by evaluating their functional impact on GR signaling. Six original GR variants, located in exon 2, led to amino acid substitutions of the N-terminal domain of GR (F65V, M86V, A229T, A304E, N374S, and R386Q), excluding mainly the activation function tau core 1 domain, the potential site of functional interaction with transcriptional coregulators. Transient cotransfection in HEK293T cells of mutated GR-expressing vectors and a luciferase reporter established dose-response curves for dexamethasone. This excluded any major transactivation abnormality of the mutated GRs (ligand concentration leading to 50% maximal transactivation capacity ≈ 0.2 nM), with maximal transactivation capacity identical to that of the wild-type (WT) GR and without modification of the potentiation of transcriptional coactivator steroid receptor coactivator 2 except in N374S. Moreover, protein expression of mutated GRs and their cytonuclear translocation studied by immunocytochemistry were almost unchanged compared with WT GR. These results underline the silent nature of these missense GR variants and call for cautious interpretation of the discovery of genetic incidentalomas by NGS in the absence of detailed characterization in order to appropriately assess their functional impact on a particular signaling pathway.

Uncovering a multitude of human glucocorticoid receptor variants: an expansive survey of a single gene

Background Glucocorticoids are commonly used in the clinical setting for their potent anti-inflammatory effects; however, significant variations in response to treatment have been demonstrated. Although the underlying mechanisms have yet to be fully understood, this variable response may be a result of alterations in human glucocorticoid receptor (hGR) expression and function. In addition to hGRα, the biologically active isoform, a screening of current databases and publications revealed five alternative splice isoforms and hundreds of variants that have been reported to date. Many of these changes in the hGR-coding gene, NR3C1, have been linked to pathophysiology. However, many studies focus on evaluating hGR expression in vitro or detecting previously reported variants.ResultsIn this study, blood from healthy volunteers, burn and asthma patients, as well as from peripheral blood mononuclear cells isolated from leukoreduced donor whole blood, were screened for NR3C1 isoforms. We identified more than 1500 variants, including an additional 21 unique splice isoforms which contain 15 new cryptic exons. A dynamic database, named the Universal hGR (UhGR), was created to annotate and visualize the variants.ConclusionThis identification of naturally occurring and stress-induced hGR isoforms, as well as the establishment of an hGR-specific database, may reveal new patterns or suggest areas of interest that will lead to the improved understanding of the human stress response system.

Lower glucocorticoid receptor gene expression and glucocorticoid receptor variants are associated with cocaine use and addiction

A new dengue vaccine was associated with increased risk of hospitalized virologically-confirmed disease during year 3 of follow-up among children age 2–5 years. Among hypotheses to explain this finding, we could not distinguish definitively between antibody dependent enhancement, waning immunity, or chance occurrence. However, any theory must account for the following: (a) the signal occurred mainly because of decreased dengue among controls rather than increased dengue among vaccinees; (b) among 48 data points, a statistically significant increase in hospitalization among vaccinated children occurred for only one age group, during one year, and in one region; (c) cumulative risk was similar for vaccinated vs. control children age 2–5 years at the end of year 5 and lower for vaccinated vs. control children among older age groups; (d) the protective effect of vaccine against hospitalization decreased from years 1–2 to years 3–5 of follow-up for all age groups and regions.

Glucocorticoid receptor variants in childhood attention-deficit/hyperactivity disorder and comorbid psychiatric disorders.

Stress results in a variety of neuroendocrine, immune and behavioral responses and represents a risk factor for many disorders. Following exposure to stress, glucocorticoids are secreted from the adrenal cortex and act via the ligand-activated glucocorticoid receptor (GR). Several polymorphisms of the GR-encoding gene NR3C1 have been described and functionally investigated. However, the impact of these variants on complex diseases such as Attention-Deficit/Hyperactivity Disorder (ADHD) is still unclear. In this study, 251 children with ADHD, 19 affected and 35 unaffected siblings, and their parents were included in a family-based association study assessing seven common variants of NR3C1 (TthIIII_rs10052957; NR3C1-I_rs10482605; ER22/23EK_rs6189/rs6190; N363S_rs56149945; BclI_rs41423247; GR-9beta_rs6198). A four-marker haplotype (TthIIII-NR3C1-I-ER22/23EK) was nominally associated with ADHD. In addition, in index children with ADHD, associations with comorbid disorders, inattentive and hyperactive-impulsive symptoms were explored. N363S minor allele carriers were more likely to show comorbid conduct disorder (CD). In our study, NR3C1 variants moderately affected ADHD and had a significant effect on comorbid CD. Therefore, NR3C1 as an important gene of the hypothalamic-pituitary-adrenal axis seems to be particularly relevant for the pathophysiology of ADHD combined with comorbid CD. For a deeper understanding, investigations in larger samples of healthy, ADHD and CD individuals are warranted.

Association of the glucocorticoid receptor D641V variant with steroid-resistant asthma: a case-control study.

Several mutations of the glucocorticoid receptor (GR) gene cause malfunction of the protein, resulting in steroid resistance. In diseases other than asthma, the GR variants I559N, D641V, and V729I have been linked to steroid resistance. The aim of this study was to evaluate the link of these GR variants in steroid-resistant (SR) asthma in the Chinese Han population. GR polymorphisms were determined in 64 SR asthma patients, 217 steroid-sensitive (SS) asthma patients and 221 healthy control (CTR) individuals. The analysis of the GR variants was performed using PCR-sequence specific primers according to the European Molecular Biology Laboratory database (NC_000005.8). In addition, ligand binding and serum cortisol levels were determined. Compared with SS asthma patients and CTRs, a significant lower frequency of the GR D641V variant AA genotype (P=0.003, 0.014, respectively) and the A allele (P=0.001, 0.009, respectively) was found in SR asthma patients. Furthermore, the equilibrium dissociation constant (Kd) of GR ligand binding in SR asthma patients with the GR D641V variant AA genotype was significantly lower compared with the AT or the TT genotype carriers (P=0.006, 0.016, respectively). There was no significant difference between the I559N and V729I GR variants on comparing SR asthma patients with SS asthma patients or CTRs. This study suggests that the D641V variant of the GR is probably associated with SR asthma in the Chinese Han population.

A Novel Mechanism to Control Cell/Tissue Specific Activities of Glucocorticoid Receptor

Cell/tissue‐specific differential actions of glucocorticoids are mediated by the glucocorticoid receptor (GR) splice variants that possess truncated N‐terminal domain (NTD), which exists in an intrinsically disordered (ID) conformation and consists of GR's major activation function, AF1. Human GR variants lacking AF1 sequences are virtually inactive whereas those lacking amino acids on the NT flanking sequences of AF1 are most active in regulating GR target genes. However, the underlying mechanism of these GR isoform specific effects is largely unknown. We hypothesize that the GR isoform specific activities are allosterically regulated through order‐disorder transition of ID NTD sequences upon interaction with TATA‐box binding protein (TBP). First, using surface plasmon resonance method, we determined the binding kinetics of TBP with different fragments of GR containing AF1 sequences. We found that placing AF1 immediately upstream from the DNA binding domain leads to strongest AF1‐TBP interaction (KD = 0.07 µM) whereas AF1C (a core sub‐domain of AF1, important for AF1 activity) showed the weakest binding (KD = 3.0 µM) when compared to AF1 (KD = 0.5 µM). Interestingly, the GR fragment consisting of entire NTD showed a biphasic binding response to TBP. Our secondary/tertiary structural analyses using biophysical methods showed that upon TBP binding, each GR fragment adopts a compact/stable structure, and the stability is proportional to the TBP binding affinity. Consistent with GR isoform specific activity, TBP‐bound GR fragment lacking NT flanking sequences showed highest AF1‐mediated GR activity. Our studies for the first time have shown a mechanism for differential activities of GR isoforms that could open unique opportunities for cell/tissue‐specific endocrine‐based therapies.

BclI polymorphism of the glucocorticoid receptor gene is associated with increased bone resorption in patients on glucocorticoid replacement therapy

Patients with primary adrenal insufficiency (PAI) and patients with congenital adrenal hyperplasia (CAH) receive weight-adapted standard glucocorticoid replacement therapy. Clinically, some patients appear more sensitive to therapeutic administration of glucocorticoids than others. Glucocorticoid sensitivity is at least partially genetically determined by polymorphisms of the glucocorticoid receptor (GR) and might influence bone mineral density (BMD). To determine if bone turnover markers and BMD are associated with the GR gene polymorphism BclI in patients with PAI and CAH. A prospective, cross-sectional study including 74 PAI and 38 CAH patients. BMD was evaluated by DXA. Serum levels of bone turnover markers, minerals, vitamins and hormones, and urinary crosslinks were measured. Patients carrying the homozygous BclI polymorphism (GG) had significantly higher serum β-CrossLaps (0.37 ± 0.34 μg/l; P < 0.05) and urinary collagen crosslinks (NTX, 68.1 ± 32.4 nmol/g; P < 0.005) despite receiving the lowest average daily hydrocortisone dose of 9.9 ± 3.7 mg/m(2) (P < 0.05). The GG genotype occurred significantly more frequently in patients with increased NTX (OR=6.7, 95% CI = 1.78-25.38) than in patients with normal NTX. However, BMD was not significantly different between different allelic variants. No significant differences in associations of the genotypes with outcomes (or in clinical characteristics) were found between the sexes. Although the sample sizes were relatively small and the results should be interpreted with caution, this study suggests that the homozygous (GG) genotype may be associated with higher bone resorption in adult PAI and CAH patients. GG-carriers needed a lower hydrocortisone dose on average supporting the concept that this GR variant is associated with increased cortisol sensitivity.

Primary Generalized Glucocorticoid Resistance and Hypersensitivity: The End-Organ Involvement in the Stress ResponseA Presentation from the European Society for Paediatric Endocrinology (ESPE) New Inroads to Child Health (NICHe) Conference on Stress Response and Child Health in Heraklion, Crete, Greece, 18 to 20 May 2012.

Primary generalized glucocorticoid resistance (PGGR or Chrousos syndrome) and primary generalized glucocorticoid hypersensitivity (PGGH) are rare genetic disorders characterized by generalized, partial target-tissue insensitivity or hypersensitivity to glucocorticoids, respectively, while also causing compensatory alterations in the activity of the hypothalamic-pituitary-adrenal axis. The molecular basis of Chrousos syndrome and PGGH has been ascribed to mutations in the gene encoding the human glucocorticoid receptor (hGR), which impair glucocorticoid signal transduction and alter tissue sensitivity to glucocorticoids. Alterations in hGR action may have important implications for many critical biological processes, such as the behavioral and physiologic responses to stress, immune responses, growth, and reproduction. This Presentation summarizes the pathophysiology, clinical manifestations, and molecular mechanisms of the PGGR and PGGH states.

Developmental expression, differential hormonal regulation and evolution of thyroid and glucocorticoid receptor variants in a marine acanthomorph teleost (Sciaenops ocellatus)

Interactions between the thyroid hormone (TH) and corticosteroid (CS) hormone axes are suggested to regulate developmental processes in vertebrates with a larval phase. To investigate this hypothesis, we isolated three nuclear receptors from a larval acanthomorph teleost, the red drum (Sciaenops ocellatus), and established their orthologies as thraa, thrb-L and gra-L using phylogenomic and functional analyses. Functional characterization of the TH receptors in COS-1 cells revealed that Thraa and Thrb-L exhibit dose-dependent transactivation of a luciferase reporter in response to T3, while SoThraa is constitutively active at a low level in the absence of ligand. To test whether interactions between the TH and CS systems occur during development, we initially quantified the in vivo receptor transcript expression levels, and then examined their response to treatment with triiodothyronine (T3) or cortisol. We find that sothraa and sothrb-L are autoregulated in response to exogenous T3 only during early larval development. T3 did not affect sogra-L expression levels, nor did cortisol alter levels of sothraa or sothrb-L at any stage. While differential expression of the receptors in response to non-canonical ligand hormone was not observed under the conditions in this study, the correlation between sothraa and sogra-L transcript abundance during development suggests a coordinated function of the TH and CS systems. By comparing the findings in the present study to earlier investigations, we suggest that the up-regulation of thraa may be a specific feature of metamorphosis in acanthomorph teleosts.

Genetic polymorphisms of the glucocorticoid receptor may affect the phenotype of women with anovulatory polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is characterized by ovarian dysfunction. The association with obesity and insulin resistance is well established. Steroid hormones play a central role in the regulation of both ovarian function and body composition. This study aims to assess the influence of known functional polymorphisms in genes that are responsible for the production, metabolism and signal transduction of steroid hormones on the susceptibility to and phenotype of PCOS. We included 518 Caucasian women with anovulatory PCOS (2003 Rotterdam criteria) and 2996 population-based controls. Functional polymorphic variants were selected in genes that affect the production of estradiol and cortisol [aromatase (CYP19), 11-beta-hydroxysteroid dehydrogenase type I (HSD11B1) and hexose-6-phosphate dehydogenase (H6PD)] and in genes for signal transduction proteins [estrogen receptor (ESR1 and ESR2) and glucocorticoid receptor (GCR)]. Genotype-frequencies were similar in PCOS cases and population-based controls. We observed possible associations between GCR genotype and LH levels that suggest an inhibitory influence of GCR, i.e., lower LH levels in association with GCR alleles that are known to increase receptor sensitivity (rs6195 and rs41423247) and higher LH levels in GCR variants that may inhibit receptor sensitivity (rs6190 and rs6198). The present study did not identify risk alleles for PCOS, although the study was limited by an absence of endocrine data for the population-based controls. However, GCR variants may influence gonadotrophin levels in women with anovulatory PCOS. We hypothesize that glucocorticoids can affect the function of the hypothalomo-pituitary-gonadal axis in humans.

Glucocorticoid Receptor-β and Receptor-γ Exert Dominant Negative Effect on Gene Repression But Not on Gene Induction

Glucocorticoid has diverse biological effects through induction or repression of its target genes via glucocorticoid receptor (GR). In addition to the wild-type GR (GR-alpha), a variety of GR variants has been reported, and these are thought to modify glucocorticoid action. Among others, GR-beta is reported be responsible for the glucocorticoid resistance frequently observed in steroid-resistant nephrotic syndrome, rheumatoid arthritis, and hematologic tumors, although the precise molecular mechanism remains unclear. In this study, we examined the function of GR-beta and some GR variants (GR-gamma and GR-Delta313-338) using GR-deficient BE(2)C and T84 cells in vitro. We found that GR-beta, when expressed alone, completely lost the capacity of both trans-activation and trans-repression on GR target genes. Interestingly, however, GR-beta showed a dominant-negative effect on GR-alpha only for its trans-repressive effects on cAMP-mediated and cAMP response element-dependent genes. Furthermore, both GR-beta and GR-gamma had dominant-negative effects on GR-alpha selectively for its trans-repressive effects on nuclear factor-kappaB-mediated and inflammation-related genes. These results suggest that 1) the GR-beta variant by itself has no receptor function, but 2) GR-beta and GR-gamma have properties to exert dominant-negative effects on the GR-alpha-mediated trans-repression, which may be responsible for the steroid resistance frequently observed in chronic inflammatory diseases under glucocorticoid therapy.

Clinical Features Associated with Glucocorticoid Receptor Polymorphisms

The glucocorticoid receptor (GR) is crucial for the effects of glucocorticoids (GCs). Several polymorphisms of the GR are associated with altered sensitivity to GCs. For the ER22/23EK polymorphism, a relative GC resistance has been demonstrated. In vivo, this was suggested by a smaller response to a dexamethasone suppression test (DST), whereas in vitro experiments showed a diminished transactivational activity. The associated features of ER22/23EK carriers consist of favorable metabolic and body compositional conditions. In elderly subjects this polymorphism was associated with longevity and decreased risk of dementia. Interestingly, recent studies also showed an increased risk of major depression. In contrast, the N363S polymorphism was reported to be associated with an enhanced sensitivity to GCs, as was demonstrated by a DST. This polymorphism has also been associated with increased body mass index (BMI) and LDL-cholesterol levels, as well as increased risk of cardiovascular disease. However, additional studies yielded conflicting results, showing no associations with being overweight. The BclI polymorphism is also associated with increased GC sensitivity. In addition, associations with increased abdominal fat mass, Crohn's disease and, remarkably, major depression have been reported. Another GR polymorphism, located in exon 9beta, is associated with increased expression and stabilization of the dominant negative splice variant GR-beta. Carriers of this polymorphism displayed a relative GC resistance in vitro as evidenced by diminished transrepressional activity, which is important for the immune system and inflammation. Associations have been found with increased inflammatory parameters, cardiovascular disease, and rheumatoid arthritis. In this article, studies concerning these clinically relevant GR variants are discussed.

Functional glucocorticoid receptor gene variants do not underlie the high variability of 17-hydroxyprogesterone screening values in healthy newborns

17-Hydroxyprogesterone (17-OHP) screening for classical congenital adrenal hyperplasia (CAH) is part of many newborn screening programs worldwide. Cut-off values are relatively high, and screening sensitivity does not reach 100%. Recently, the glucocorticoid receptor (GR) N363S-variant has been linked to relatively low degree of virilization and comparatively lower 17-OHP serum concentrations in clinically diagnosed female CAH patients. We sought to determine whether functional GR gene variants, either increasing (N363S, BclI) or decreasing GR sensitivity (R23K), underlie the variable 17-OHP screening levels in healthy newborns. GR genotypes were compared with 17-OHP screening values in 1000 random samples from routine screening. 17-OHP was measured by conventional immunoassay (TRFIA) and a liquid chromatography-tandem mass spectrometry method (LC-MS/MS), which has been shown to increase screening specificity by steroid profiling and avoiding cross-reactions of the 17-OHP-antibody. There was no significant association of 17-OHP with GR genotypes, even after inclusion of gestational and postnatal age as covariates. However, among LC-MS/MS steroid measurements, we observed some unexpected trends, including lower 11-deoxycortisol concentrations in both 363S- and 23K-carriers. For carriers of the frequent BclI variant, linear regression analysis revealed a significant increase of 4-androstenedione levels with every mutant allele inherited. Functional GR variants do not underlie the variation of 17-OHP values observed in healthy individuals. However, whether and to which extent genetically determined differences in individual GR sensitivity influence 17-OHP screening levels in conditions of a pathological hypothalamus-pituitary-adrenal gland-axis stimulation and thus may explain false-negative screening results in those affected by CAH remains to be investigated.

Effect of TNF-α on Estrogen Metabolism and Endometrial Cells: Potential Physiological and Pathological Relevance

Context: Estrogen and its metabolites play a critical role in the pathophysiology of the endometrium. The bioavailability of estrogen and estrogen metabolites in endometrial tissues depends on the expression of enzymes involved in estrogen biosynthesis and metabolism. Substantial evidence indicates that estrogen-dependent endometrial disorders are also associated with proinflammatory milieu. However, the mechanism whereby inflammation contributes to these conditions is not known. Objective: Investigate the effect of the tumor necrosis factor(TNF) on estrogen metabolism and on the expression of estrogen-metabolizing genes in human endometrial glandular epithelial cells (EM1). Design: EM1 were treated with 17 -estradiol (E2) with or without TNF. Capillary liquid chromatography-tandem mass spectrometry analysis was used for quantitative measurement of estrogens and estrogen metabolites. Western blot analysis, reporter gene assay, and real time RT-PCR were used to assess the expression of estrogen-metabolizing genes. Results: TNFtreatment significantly increased the level of total estrogen and estrogen metabolites and significantly increased the rate of conversion of estrone (E1) into E2. TNFalso enhanced the oxidative metabolism of estrogen into catecholestrogens with concomitant inhibition of their conversion into methoxyestrogens. Gene expression analysis revealed that TNFinduced the expression of genes involved in E2 biosynthesis (SF-1 and CYP19) and activation (HSD17B1 and CYP1B1) with simultaneous repression of genes involved in estrogen inactivation (HSD17B2; COMT; and NQO1). Conclusion: TNFincreases the local estrogen biosynthesis in human endometrial glandular cells and directs estrogen metabolism into more hormonally active and carcinogenic metabolites. These effects may impact many physiological and pathological processes that occur within endometrium. Glucocorticoid Receptor Gene Variant in the 3 Untranslated Region Is Associated with Multiple Measures of Blood Pressure Charles C. Chung, Lawrence Shimmin, Sivamani Natarajan, Craig L. Hanis, Eric Boerwinkle, and James E. Hixson (J. Clin. Endocrinol. Metab., published October 14, 2008, 10.1210/jc.2008-1089) ABSTRACT Context: The glucocorticoid receptor (GR) is a key hormone in the hypothalamus-pituitary-adrenal axis that regulates many pathways including blood pressure homeostasis. Thus, GR gene variation may influence interindividual differences in blood pressure in human populations. Objective: We resequenced individual GR alleles for comprehensive discovery of GR variants and their chromosomal phase in three major American ethnic groups. We examined the influence of GR variants on blood pressure in large numbers of families using family-based association methods. Design and Participants: For association studies, we genotyped GR variants in family members from the GENOA study that were measured for multiple blood pressure traits. The GENOA families consisted of African Americans, Mexican Americans, and European Americans. Main Measurements: The blood pressure measurements for association studies included systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP). T R A N S L A T I O N A L H I G H L I G H T S F R O M J C E MContext: The glucocorticoid receptor (GR) is a key hormone in the hypothalamus-pituitary-adrenal axis that regulates many pathways including blood pressure homeostasis. Thus, GR gene variation may influence interindividual differences in blood pressure in human populations. Objective: We resequenced individual GR alleles for comprehensive discovery of GR variants and their chromosomal phase in three major American ethnic groups. We examined the influence of GR variants on blood pressure in large numbers of families using family-based association methods. Design and Participants: For association studies, we genotyped GR variants in family members from the GENOA study that were measured for multiple blood pressure traits. The GENOA families consisted of African Americans, Mexican Americans, and European Americans. Main Measurements: The blood pressure measurements for association studies included systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP). T R A N S L A T I O N A L H I G H L I G H T S F R O M J C E M

Glucocorticoid Receptor Gene Variant in the 3′ Untranslated Region Is Associated with Multiple Measures of Blood Pressure

The glucocorticoid receptor (GR) is a key hormone in the hypothalamus-pituitary-adrenal axis that regulates many pathways including blood pressure homeostasis. Thus, GR gene variation may influence interindividual differences in blood pressure in human populations. We resequenced individual GR alleles for comprehensive discovery of GR variants and their chromosomal phase in three major American ethnic groups. We examined the influence of GR variants on blood pressure in large numbers of families using family-based association methods. For association studies, we genotyped GR variants in family members from the GENOA study that were measured for multiple blood pressure traits. The GENOA families consisted of African Americans, Mexican Americans, and European Americans. The blood pressure measurements for association studies included systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP). SNPs identified by resequencing were tested for associations with blood pressure measures in GENOA families. Analysis of individual SNPs identified significant associations of rs6198 A/G in exon 9β with multiple blood pressure measures in European Americans. Analysis of GR haplotypes found significant associations of a haplotype that is distinguished by rs6198 A/G. Significant associations of blood pressure with rs6198 A/G likely reflect allelic effects on GR signaling. This SNP disrupts a 3′ UTR sequence element in exon 9β that destabilizes mRNA, resulting in increased production of the inactive GRβ isoform. Excess heterodimerization with the active GRα isoform may reduce GR signaling with subsequent physiological effects on blood pressure regulation.

P02-64 Glucocorticoid receptor gene polymorphisms in Italian patients with anorexia and bulimia nervosa

The etiopathogenesis of eating disorders (ED) is complex and poorly understood. The hypothalamic-pituitary-adrenal (HPA) axis, involved in the biological response to stress, could influence the onset and the course of ED.) Several variants in the Glucocorticoid receptor (GR) gene have been related to different metabolic parameters suggesting a possible role in ED. We studied if genetic variants of GR could represent potential risk factors for the development of Anorexia Nervosa (AN) and Bulimia Nervosa (BN).We investigated the distribution of several single nucleotide polymorphisms (SNPs) of the GR including N363S (rs6195), Er22/23EK (rs6189-6190), A/G SNP in exon 9beta (rs6198) and the intronic BclI polymorphism (rs41423247), in 118 Italian patients affected by AN and in 108 patients with BN. Moreover we studied 116 normal individuals and 177 obese subjects. The distributions of genotypes and allele frequency of the SNPs in all studied groups followed Hardy-Weinberg equilibrium and did not significantly differ from that of controls. A trend towards association was observed in case-control association analysis (p=0.07) for rs6198. A correlation of metabolic parameters to the GR genotypes was performed.We report the analysis of different GR SNPs for the first time in Italian patients with AN and BN. We failed to detect an allelic association between the studied SNPs in the GR gene and AN and BN.None of the variants seems to influence these pathologies, not supporting a role for the GR gene as genetic risk factors for ED.