Concept: Mineralocorticoid receptor
Generalized glucocorticoid resistance caused by a novel two-nucleotide deletion in the hormone-binding domain of the glucocorticoid receptor gene NR3C1
- European journal of endocrinology / European Federation of Endocrine Societies
- Published almost 8 years ago
Generalized glucocorticoid resistance is characterized by impaired cortisol signaling, resulting from mutations of the glucocorticoid receptor (GR) gene NR3C1. The objective of our study was to identify the causative mutation in a patient with clinical manifestations compatible with generalized glucocorticoid resistance and to determine the functional consequences of the mutation. The possible occurrence of NR3C1 mutations in a selected group of hypertensive subjects with low plasma renin and aldosterone levels was also explored.
The purpose of this study is to evaluate long-term effects of spironolactone, an affordable and widely used aldosterone receptor blocker, in patients with heart failure (HF) and mild or no symptoms.
PURPOSE: Heart failure (CHF) guidelines recommend mineralocorticoid receptor antagonists for all symptomatic patients treated with a combination of ACE inhibitors/angiotensin receptor blockers (ARBs) and beta-blockers. As opposed to both eplerenone trials, patients in RALES (spironolactone) received almost no beta-blockers. Since pharmacological properties differ between eplerenone and spironolactone, the prognostic benefit of spironolactone added to this baseline combination therapy needs clarification. METHODS: We included 4,832 CHF patients with chronic systolic dysfunction from the Norwegian Heart Failure Registry and the heart failure outpatients' clinic of the University of Heidelberg. Propensity scores for spironolactone receipt were calculated for each patient and used for matching to patients without spironolactone. RESULTS: During a total follow-up of 17,869 patient-years, 881 patients (27.0 %) died in the non-spironolactone group and 445 (28.4 %) in the spironolactone group. Spironolactone was not associated with improved survival, neither in the complete sample (HR 0.82; 95 % CI 0.64-1.07; HR 1.03; 95 % CI 0.88-1.20; multivariate and propensity score adjusted respectively), nor in the propensity-matched cohort (HR 0.98; 95 % CI 0.82-1.18). CONCLUSION: In CHF outpatients we were unable to observe an association between the use of spironolactone and improved survival when administered in addition to a combination of ACE/ARB and beta-blockers.
Aldosterone is synthesized in and activates bulbospinal neurons through mineralocorticoid receptors and ENaCs in the RVLM
- Hypertension research : official journal of the Japanese Society of Hypertension
- Published over 7 years ago
The effects of aldosterone and mineralocorticoid receptor (MR) blockers on presympathetic neurons in the rostral ventrolateral medulla (RVLM) are well studied. To directly investigate whether aldosterone, eplerenone (an MR blocker), FAD286 (an aldosterone synthase inhibitor) and benzamil (an epithelial sodium channel (ENaC) blocker) affect RVLM neurons, we examined changes in the membrane potentials (MPs) of bulbospinal RVLM neurons using the whole-cell patch-clamp technique during superfusion with these drugs to brainstem-spinal cord preparations. Aldosterone superfusion (0.1 μmol/l) depolarized the RVLM neurons. In contrast, eplerenone superfusion (1 μmol/l) hyperpolarized them. To evaluate the existence of aldosterone, FAD286 superfusion (10 μmol/l) was performed, and the RVLM neurons became hyperpolarized during FAD superfusion. These data suggest that MRs exist and that aldosterone is synthesized in the brainstem. Benzamil superfusion (1 μmol/l) hyperpolarized the RVLM neurons. To clarify whether aldosterone, eplerenone, FAD286 and benzamil acted directly on the RVLM neurons, a low-Ca(2+), high-Mg(2+) solution was used to block the synaptic input to the RVLM neurons, and the above-mentioned drugs were added during the low-Ca(2+) superfusion. During the aldosterone superfusion, the RVLM neurons became depolarized, and they became hyperpolarized during eplerenone, FAD286 or benzamil superfusion. Importantly, when aldosterone was superfused after the benzamil solution, the MPs of the RVLM neurons did not depolarize. These results suggest that MRs are present in the RVLM neurons and that aldosterone is synthesized in the RVLM. The RVLM neurons themselves possess ENaCs, and ENaCs are the underlying mechanism by which aldosterone activates RVLM neurons.Hypertension Research advance online publication, 31 January 2013; doi:10.1038/hr.2012.224.
Eplerenone (EPL), an antagonist of the mineralocorticoid receptor, is beneficial for atrial fibrillation and atrial fibrosis. However, the underlying mechanism remains less well known. We aimed to investigate the effect of EPL on atrial fibrosis using a mouse with selective atrial fibrosis and to explore the underlying mechanisms.
AZD9977 is the first MR modulator in clinical development exerting similar organ protection as eplerenone with minimal urinary electrolyte effects in pre-clinical studies. The aim was to perform the initial clinical assessment of AZD9977.
Persistent congestion is associated with worse outcomes in acute heart failure (AHF). Mineralocorticoid receptor antagonists administered at high doses may relieve congestion, overcome diuretic resistance, and mitigate the effects of adverse neurohormonal activation in AHF.
The hypothalamic-pituitary-adrenal (HPA) axis has been implicated in the pathophysiology of a variety of mood and cognitive disorders. Neuroendocrine studies have demonstrated HPA axis overactivity in major depression, a relationship of HPA axis activity to cognitive performance and a potential role of HPA axis genetic variation in cognition. The present study investigated the simultaneous roles HPA axis activity, clinical symptomatology and HPA genetic variation play in cognitive performance. Patients with major depression with psychotic major depression (PMD) and with nonpsychotic major depression (NPMD) and healthy controls (HC) were studied. All participants underwent a diagnostic interview and psychiatric ratings, a comprehensive neuropsychological battery, overnight hourly blood sampling for cortisol and genetic assessment. Cognitive performance differed as a function of depression subtype. Across all subjects, cognitive performance was negatively correlated with higher cortisol, and PMD patients had higher cortisol than did NPMDs and HCs. Cortisol, clinical symptoms and variation in genes, NR3C1 (glucocorticoid receptor; GR) and NR3C2 (mineralocorticoid receptor; MR) that encode for GRs and MRs, predicted cognitive performance. Beyond the effects of cortisol, demographics and clinical symptoms, NR3C1 variation predicted attention and working memory, whereas NR3C2 polymorphisms predicted memory performance. These findings parallel the distribution of GR and MR in primate brain and their putative roles in specific cognitive tasks. HPA axis genetic variation and activity were important predictors of cognition across the entire sample of depressed subjects and HR. GR and MR genetic variation predicted unique cognitive functions, beyond the influence of cortisol and clinical symptoms. GR genetic variation was implicated in attention and working memory, whereas MR was implicated in verbal memory.Molecular Psychiatry advance online publication, 16 August 2016; doi:10.1038/mp.2016.120.
A major deleterious side effect of glucocorticoids is skin atrophy. Glucocorticoids activate the glucocorticoid and the mineralocorticoid (MR) receptor, both present in epidermis. We hypothesized that glucocorticoid-induced epidermal atrophy may be related to inappropriate occupancy of MR by glucocorticoids. We evaluated whether epidermal atrophy induced by the topical glucocorticoid clobetasol could be limited by co-administration of MR antagonist. In cultured human skin explants, the epidermal atrophy induced by clobetasol was significantly limited by MR antagonism (canrenoate, eplerenone). Blockade of the epithelial sodium channel ENaC by phenamil was also efficient, identifying a role of MR-ENaC cascade in keratinocytes, acting through restoration of clobetasol-induced impairment of keratinocyte proliferation. In the SPIREPI randomized double-blind controlled trial, gels containing clobetasol, the MR antagonist spironolactone, both agents or placebo were applied on four zones of the forearms of 23 healthy volunteers for 28 days. Primary outcome was histological thickness of the epidermis with clobetasol alone or clobetasol+spironolactone. Spironolactone alone did not affect epidermis thickness but co-application of clobetasol and spironolactone limited significantly clobetasol-induced atrophy and was well tolerated. Altogether these findings identify MR as a factor regulating epidermal homeostasis and suggest that topical MR blockade could limit glucocorticoid-induced epidermal atrophy.Journal of Investigative Dermatology accepted article preview online, 10 February 2015. doi:10.1038/jid.2015.44.
Heart failure (HF), with or without reduced ejection fraction, and multidrug-resistant hypertension (RHT) are major worldwide health problems of ever-increasing proportions. The mineralocorticoid receptor antagonists (MRAs) spironolactone and eplerenone have proved valuable additions to the overall management of these disorders in patients without significant renal dysfunction.