Generalized glucocorticoid resistance caused by a novel two-nucleotide deletion in the hormone-binding domain of the glucocorticoid receptor gene NR3C1

Molecular mechanisms of glucocorticoid resistance

BACKGROUND

As a powerful anti-inflammatory, immunosuppressive, and antiproliferative drug, glucocorticoid (GC) plays an important role in the treatment of various diseases. However, some patients may experience glucocorticoid resistance (GCR) in clinical, and its molecular mechanism have not been determined.

METHODS

The authors performed a review of the literature on GCR focusing on mutations in the NR3C1 gene and impaired glucocorticoid receptor (GR) signalling, using METSTR (2000 through May 2022) to identify original articles and reviews on this topic. The search terms included 'glucocorticoid resistance/insensitive', 'steroid resistance/insensitive', 'NR3C1', and 'glucocorticoid receptor'.

RESULTS

Primary GCR is mainly caused by NR3C1 gene mutation, and 31 NR3C1 gene mutations have been reported so far. Secondary GCR is caused by impaired GC signalling pathways, including decreased expression of GR, impaired nuclear translocation of GR, and impaired binding of GR to GC and GR to target genes. However, the current research is more on the expression level of GR, and there are relatively few studies on other mechanisms. In addition, methods for improving GC sensitivity are rarely reported.

CONCLUSION

The molecular mechanisms of GCR are complex and may differ in different diseases or different patients. In future studies, when exploring the mechanism of GCR, methods to improve GC sensitivity should also be investigated.

Role of glucocorticoid receptor mutations in hypertension and adrenal gland hyperplasia

Hypertension is one of the leading causes of premature death in humans and exhibits a complex aetiology including environmental and genetic factors. Mutations within the glucocorticoid receptor (GR) can cause glucocorticoid resistance, which is characterized by several clinical features like hypercortisolism, hypokalaemia, adrenal hyperplasia and hypertension. Altered glucocorticoid receptor signalling further affects sodium and potassium homeostasis as well as blood pressure regulation and cell proliferation and differentiation that influence organ development and function. In salt-sensitive hypertension, excessive renal salt transport and sympathetic nervous system stimulation may occur simultaneously, and, thus, both the mineralocorticoid receptor (MR) and the GR-signalling may be implicated or even act interdependently. This review focuses on identified GR mutations in human primary generalized glucocorticoid resistance (PGGR) patients and their related clinical phenotype with specific emphasis on adrenal gland hyperplasia and hypertension. We compare these findings to mouse and rat mutants harbouring genetically engineered mutations to further dissect the cause and/or the consequence of clinical features which are common or different.

Molecular Probes, Chemosensors, and Nanosensors for Optical Detection of Biorelevant Molecules and Ions in Aqueous Media and Biofluids

Synthetic molecular probes, chemosensors, and nanosensors used in combination with innovative assay protocols hold great potential for the development of robust, low-cost, and fast-responding sensors that are applicable in biofluids (urine, blood, and saliva). Particularly, the development of sensors for metabolites, neurotransmitters, drugs, and inorganic ions is highly desirable due to a lack of suitable biosensors. In addition, the monitoring and analysis of metabolic and signaling networks in cells and organisms by optical probes and chemosensors is becoming increasingly important in molecular biology and medicine. Thus, new perspectives for personalized diagnostics, theranostics, and biochemical/medical research will be unlocked when standing limitations of artificial binders and receptors are overcome. In this review, we survey synthetic sensing systems that have promising (future) application potential for the detection of small molecules, cations, and anions in aqueous media and biofluids. Special attention was given to sensing systems that provide a readily measurable optical signal through dynamic covalent chemistry, supramolecular host-guest interactions, or nanoparticles featuring plasmonic effects. This review shall also enable the reader to evaluate the current performance of molecular probes, chemosensors, and nanosensors in terms of sensitivity and selectivity with respect to practical requirement, and thereby inspiring new ideas for the development of further advanced systems.

Primary Generalized Glucocorticoid Resistance and Hypersensitivity Syndromes: A 2021 Update

Glucocorticoids are the final products of the neuroendocrine hypothalamic-pituitary-adrenal axis, and play an important role in the stress response to re-establish homeostasis when it is threatened, or perceived as threatened. These steroid hormones have pleiotropic actions through binding to their cognate receptor, the human glucocorticoid receptor, which functions as a ligand-bound transcription factor inducing or repressing the expression of a large number of target genes. To achieve homeostasis, glucocorticoid signaling should have an optimal effect on all tissues. Indeed, any inappropriate glucocorticoid effect in terms of quantity or quality has been associated with pathologic conditions, which are characterized by short-term or long-lasting detrimental effects. Two such conditions, the primary generalized glucocorticoid resistance and hypersensitivity syndromes, are discussed in this review article. Undoubtedly, the tremendous progress of structural, molecular, and cellular biology, in association with the continued progress of biotechnology, has led to a better and more in-depth understanding of these rare endocrinologic conditions, as well as more effective therapeutic management.

Generalized and tissue specific glucocorticoid resistance

Glucocorticoids (GCs) are steroid hormones that influence several physiologic functions and are among the most frequently prescribed drugs worldwide. Resistance to GCs has been observed in the context of the familial generalized GC resistance (Chrousos' syndrome) or tissue specific GC resistance in chronic inflammatory states. In this review, we have summarized the major factors that influence individual glucocorticoid sensitivity/resistance. The fine-tuning of GC action is determined in a tissue-specific fashion that includes the combination of different GC receptor promoters, translation initiation sites, splice isoforms, interacting proteins, post-translational modifications, and alternative mechanisms of signal transduction.

Complex karyotype with cryptic FUS gene rearrangement and deletion of NR3C1 and VPREB1 genes in childhood B-cell acute lymphoblastic leukemia: A case report

B-cell acute lymphoblastic leukemia (B-ALL) is a hematopoietic malignancy characterized by overproduction of immature B-lymphoblasts. B-ALL is the most common pediatric tumor and remains the leading cause of mortality in children and adolescents. Molecular and cytogenetic analyses of B-ALL revealed recurrent genetic and structural genomic alterations which are routinely applied for diagnosis, prognosis and choice of treatment regimen. The present case report describes a 4-year-old female diagnosed with B-ALL. GTG-banding at low resolution revealed an abnormal clone with 46,XX,?t(X;19)(q13;q13.3),der(9) besides normal cells. Molecular cytogenetics demonstrated a balanced translocation between chromosomes 16 and 19, and an unbalanced translocation involving chromosomes 5 and 9. A locus-specific probe additionally identified that the FUS gene in 16p11.2 was split and its 5' region was translocated to subband 19q13.33, whereas the 3' region of the FUS gene remained on the derivative chromosome 16. Overall, this complex karyotype included four different chromosomes and five break events. Further analyses, including array-comparative genomic hybridization, additionally revealed biallelic deletion of the tumor suppressor genes CDKN2A/B, and deletion of the NR3C1 and VPREB1 genes. The patient passed away under treatment due to sepsis.

Overview of Monogenic Forms of Hypertension Combined With Hypokalemia

Hypertension is an important risk factor in many conditions and creates a heavy burden of disease and mortality globally. Polygenic hypertension is the most common form; however, it is increasingly recognized that monogenic hypertension is not rare, especially in patients with electrolyte disorders. Single genetic alterations are associated with plasma volume expansion and catecholamines/sympathetic excess with simultaneously increased potassium excretion in the urine and potassium intracellular shift. Early-onset refractory hypertension and profound hypokalemia are characteristics of monogenic hypertension. However, accumulated evidence shows the existence of phenotypic heterogeneity in monogenic hypertension meaning that, even for mild symptoms, clinicians cannot easily exclude the possibility of monogenic hypertension. Genetic, epigenetic and non-genetic factors are all possible mechanisms influencing phenotypic diversity. Genetic sequencing is a precise and efficient method that can broaden the mutant gene spectrum of the disease and is very helpful for understanding the pathophysiology of monogenic hypertension. Genetic sequencing, along with biochemical tests and imaging modalities, is essential for the early diagnosis and targeted management of monogenic hypertension to avoid long-term catastrophic complications.

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

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.

Explorative visual analytics on interval-based genomic data and their metadata

Background

With the wide-spreading of public repositories of NGS processed data, the availability of user-friendly and effective tools for data exploration, analysis and visualization is becoming very relevant. These tools enable interactive analytics, an exploratory approach for the seamless “sense-making” of data through on-the-fly integration of analysis and visualization phases, suggested not only for evaluating processing results, but also for designing and adapting NGS data analysis pipelines.

Results

This paper presents abstractions for supporting the early analysis of NGS processed data and their implementation in an associated tool, named GenoMetric Space Explorer (GeMSE). This tool serves the needs of the GenoMetric Query Language, an innovative cloud-based system for computing complex queries over heterogeneous processed data. It can also be used starting from any text files in standard BED, BroadPeak, NarrowPeak, GTF, or general tab-delimited format, containing numerical features of genomic regions; metadata can be provided as text files in tab-delimited attribute-value format. GeMSE allows interactive analytics, consisting of on-the-fly cycling among steps of data exploration, analysis and visualization that help biologists and bioinformaticians in making sense of heterogeneous genomic datasets. By means of an explorative interaction support, users can trace past activities and quickly recover their results, seamlessly going backward and forward in the analysis steps and comparative visualizations of heatmaps.

Conclusions

GeMSE effective application and practical usefulness is demonstrated through significant use cases of biological interest. GeMSE is available at http://www.bioinformatics.deib.polimi.it/GeMSE/, and its source code is available at https://github.com/Genometric/GeMSE under GPLv3 open-source license.

Integration of genetic and clinical risk factors improves prognostication in relapsed childhood B-cell precursor acute lymphoblastic leukemia

Somatic genetic abnormalities are initiators and drivers of disease and have proven clinical utility at initial diagnosis. However, the genetic landscape and its clinical utility at relapse are less well understood and have not been studied comprehensively. We analyzed cytogenetic data from 427 children with relapsed B-cell precursor ALL treated on the international trial, ALLR3. Also we screened 238 patients with a marrow relapse for selected copy number alterations (CNAs) and mutations. Cytogenetic risk groups were predictive of outcome postrelapse and survival rates at 5 years for patients with good, intermediate-, and high-risk cytogenetics were 68%, 47%, and 26%, respectively (P < .001). TP53 alterations and NR3C1/BTG1 deletions were associated with a higher risk of progression: hazard ratio 2.36 (95% confidence interval, 1.51-3.70, P < .001) and 2.15 (1.32-3.48, P = .002). NRAS mutations were associated with an increased risk of progression among standard-risk patients with high hyperdiploidy: 3.17 (1.15-8.71, P = .026). Patients classified clinically as standard and high risk had distinct genetic profiles. The outcome of clinical standard-risk patients with high-risk cytogenetics was equivalent to clinical high-risk patients. Screening patients at relapse for key genetic abnormalities will enable the integration of genetic and clinical risk factors to improve patient stratification and outcome. This study is registered at www.clinicaltrials.org as #ISCRTN45724312.

Targeted sequencing of refractory myeloma reveals a high incidence of mutations in CRBN and Ras pathway genes

In this study, targeted sequencing to screen 50 multidrug refractory multiple myeloma (rMM) patients was performed by using the Multiple Myeloma Mutation Panel. Patients were pretreated with both immunomodulatory drugs (IMiDs) and proteasome inhibitors (PIs), and 88%, 78%, and 68% were refractory to an IMiD, a PI, or both, respectively. The majority of patients had progressive (82%) or refractory (78%) disease immediately before sampling, with 43% being IMiD refractory and 46% being PI refractory in the most recent line of therapy. Compared with newly diagnosed MM, an increased prevalence of mutations in the Ras pathway genes KRAS, NRAS, and/or BRAF (72%), as well as TP53 (26%), CRBN (12%), and CRBN pathway genes (10%) was observed. Longitudinal analyses performed in 3 patients with CRBN mutations at time of IMiD resistance confirmed that these mutations were undetectable at earlier, IMiD-sensitive time points. Furthermore, the functional introduction of these mutations in MM cells conferred lenalidomide resistance in vitro. These data indicate a differential genetic landscape in rMM associated with drug response.

Time course of the response to ACTH in pig: biological and transcriptomic study

Background

HPA axis plays a major role in physiological homeostasis. It is also involved in stress and adaptive response to the environment. In farm animals in general and specifically in pigs, breeding strategies have highly favored production traits such as lean growth rate, feed efficiency and prolificacy at the cost of robustness. On the hypothesis that the HPA axis could contribute to the trade-off between robustness and production traits, we have designed this experiment to explore individual variation in the biological response to the main stress hormone, cortisol, in pigs. We used ACTH injections to trigger production of cortisol in 120 juvenile Large White (LW) pigs from 28 litters and the kinetics of the response was measured with biological variables and whole blood gene expression at 4 time points. A multilevel statistical analysis was used to take into account the longitudinal aspect of the data.

Results

Cortisol level reached its peak 1 h after ACTH injection. White blood cell composition was modified with a decrease of lymphocytes and monocytes and an increase of granulocytes (FDR<0.05). Basal level of cortisol was correlated with birth and weaning weights. Microarray analysis identified 65 unique genes of which expression responded to the injection of ACTH (adjusted P<0.05). These genes were classified into 4 clusters with distinctive kinetics in response to ACTH injection. The first cluster identified genes strongly correlated to cortisol and previously reported as being regulated by glucocorticoids. In particular, DDIT4, DUSP1, FKBP5, IL7R, NFKBIA, PER1, RGS2 and RHOB were shown to be connected to each other by the glucocorticoid receptor NR3C1. Most of the differentially expressed genes that encode transcription factors have not been described yet as being important in transcription networks involved in stress response. Their co-expression may mean co-regulation and they could thus provide new patterns of biomarkers of the individual sensitivity to cortisol.

Conclusions

We identified 65 genes as biological markers of HPA axis activation at the gene expression level. These genes might be candidates for a better understanding of the molecular mechanisms of the stress response.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-2118-8) contains supplementary material, which is available to authorized users.

A secretagogin locus of the mammalian hypothalamus controls stress hormone release

A hierarchical hormonal cascade along the hypothalamic-pituitary-adrenal axis orchestrates bodily responses to stress. Although corticotropin-releasing hormone (CRH), produced by parvocellular neurons of the hypothalamic paraventricular nucleus (PVN) and released into the portal circulation at the median eminence, is known to prime downstream hormone release, the molecular mechanism regulating phasic CRH release remains poorly understood. Here, we find a cohort of parvocellular cells interspersed with magnocellular PVN neurons expressing secretagogin. Single-cell transcriptome analysis combined with protein interactome profiling identifies secretagogin neurons as a distinct CRH-releasing neuron population reliant on secretagogin's Ca(2+) sensor properties and protein interactions with the vesicular traffic and exocytosis release machineries to liberate this key hypothalamic releasing hormone. Pharmacological tools combined with RNA interference demonstrate that secretagogin's loss of function occludes adrenocorticotropic hormone release from the pituitary and lowers peripheral corticosterone levels in response to acute stress. Cumulatively, these data define a novel secretagogin neuronal locus and molecular axis underpinning stress responsiveness.

Glucocorticoid sensitivity in health and disease

Glucocorticoids regulate many physiological processes and have an essential role in the systemic response to stress. For example, gene transcription is modulated by the glucocorticoid-glucocorticoid receptor complex via several mechanisms. The ultimate biologic responses to glucocorticoids are determined by not only the concentration of glucocorticoids but also the differences between individuals in glucocorticoid sensitivity, which is influenced by multiple factors. Differences in sensitivity to glucocorticoids in healthy individuals are partly genetically determined by functional polymorphisms of the gene that encodes the glucocorticoid receptor. Hereditary syndromes have also been identified that are associated with increased and decreased sensitivity to glucocorticoids. As a result of their anti-inflammatory properties, glucocorticoids are widely used in the treatment of allergic, inflammatory and haematological disorders. The variety in clinical responses to treatment with glucocorticoids reflects the considerable variation in glucocorticoid sensitivity between individuals. In immune-mediated disorders, proinflammatory cytokines can induce localized resistance to glucocorticoids via several mechanisms. Individual differences in how tissues respond to glucocorticoids might also be involved in the predisposition for and pathogenesis of the metabolic syndrome and mood disorders. In this Review, we summarize the mechanisms that influence glucocorticoid sensitivity in health and disease and discuss possible strategies to modulate glucocorticoid responsiveness.

Glucocorticoid receptor is required for foetal heart maturation

Glucocorticoids are vital for the structural and functional maturation of foetal organs, yet excessive foetal exposure is detrimental to adult cardiovascular health. To elucidate the role of glucocorticoid signalling in late-gestation cardiovascular maturation, we have generated mice with conditional disruption of glucocorticoid receptor (GR) in cardiomyocytes and vascular smooth muscle cells using smooth muscle protein 22-driven Cre recombinase (SMGRKO mice) and compared them with mice with global deficiency in GR (GR(-/-)). Echocardiography shows impaired heart function in both SMGRKO and GR(-/-) mice at embryonic day (E)17.5, associated with generalized oedema. Cardiac ultrastructure is markedly disrupted in both SMGRKO and GR(-/-) mice at E17.5, with short, disorganized myofibrils and cardiomyocytes that fail to align in the compact myocardium. Failure to induce critical genes involved in contractile function, calcium handling and energy metabolism underpins this common phenotype. However, although hearts of GR(-/-) mice are smaller, with 22% reduced ventricular volume at E17.5, SMGRKO hearts are normally sized. Moreover, while levels of mRNA encoding atrial natriuretic peptide are reduced in E17.5 GR(-/-) hearts, they are normal in foetal SMGRKO hearts. These data demonstrate that structural, functional and biochemical maturation of the foetal heart is dependent on glucocorticoid signalling within cardiomyocytes and vascular smooth muscle, though some aspects of heart maturation (size, ANP expression) are independent of GR at these key sites.