ABSTRACT: Aldosterone excess is involved in cardiac diseases. The mechanisms are still unclears. Mice were treated for 7 days with aldosterone and a whole genome microarray analysis was performed.
Project description:Aldosterone excess is involved in cardiac diseases. The mechanisms are still unclears. Mice were treated for 7 days with aldosterone and a whole genome microarray analysis was performed. Two-group experiment: Untreated mice (Ctrl), mice + aldosterone treatment (Aldo). One comparisons: Ctrl vs Aldo
Project description:Inappropriate mineralocorticoid receptor (MR) activation is involved in cardiac diseases. The mechanisms are still unclears. Mice overexpressing MR in cardiomyocytes (MR-Cardio) and their controls (Ctrl) were treated for 7 days with aldosterone and a whole genome microarray analysis was performed.
Project description:Inappropriate mineralocorticoid receptor (MR) activation is involved in cardiac diseases. MR binds aldosterone, but also glucocorticoids; the identity of the ligand responsible for the deleterious effects of cardiac MR activation is still unclear. Mice overexpressing MR in cardiomyocytes (MR-Cardio) and their controls (Ctrl) were treated for 7 days with aldosterone or corticosterone and a whole genome microarray analysis was performed.
Project description:The overall objective of the study was to screen for microRNAs regulated by aldosterone and salt in rat left ventricles . Primary aldosteronism is characterized by excess aldosterone (ALDO) secretion independent of the renin-angiotensin system and accounts for ~10% of hypertensive patients. Excess ALDO, inappropriate for the salt intake status, causes cardiac hypertrophy, inflammation, fibrosis and hypertension. The molecular mechanisms that trigger the onset and progression of ALDO-mediated cardiac injury are poorly understood. MicroRNAs (miRNAs) are endogenous, small, non-coding RNAs that have been implicated in diverse cardiac pathologies, yet very little is known about their regulation and role in ALDO-mediated cardiac injury. To elucidate the regulation of miRNAs in ALDO-mediated cardiac injury, we performed a time-series analysis of left ventricle (LV) miRNA expression. Uninephrectomized male Sprague Dawley rats were treated with ALDO (0.75 µg/h) infusion and SALT (1.0% NaCl/0.3% KCl) in the drinking water for up to 8 weeks. ALDO/SALT time-dependently modulated the expression of multiple miRNAs in the LV. miR-21 was the most upregulated miRNA after 2 weeks of treatment and remained elevated until the end of the study. To elucidate the role of miR-21 in ALDO/SALT-mediated cardiac injury, miR-21 was downregulated using antagomirs in ALDO/SALT-treated rats. miR-21 downregulation exacerbated ALDO/SALT-mediated cardiac hypertrophy, fibrosis and inflammation markers gene expression, interstitial and perivascular fibrosis, OH-proline content and cardiac dysfunction. These results suggest that ALDO/SALT-mediated cardiac miR-21 upregulation may be a compensatory mechanism that mitigates ALDO/SALT-mediated cardiac deleterious effects. We speculate that miR-21 supplementation would have beneficial effects in reverting or mitigating cardiac injury and dysfunction in patients with primary aldosteronism.
Project description:Effects of aldosterone on the transcriptome in distal colon. Expression of genes was studied in distal colon surface cells from aldosterone treated vs. vehicle treated rats.
Project description:The steroid hormone aldosterone plays a role in vascular function and disease. Aldosterone activates the mineralocorticoid receptor (MR), a ligand-activated transcription factor. MR have been found to be expressed in vascular cells and vessels. We used microarrays to identify the global programme of gene expression changes in mouse aortas treated with vehicle (DMSO) or aldosterone.
Project description:The steroid hormone aldosterone plays a role in vascular function and disease. Aldosterone activates the mineralocorticoid receptor (MR), a ligand-activated transcription factor. MR have been found to be expressed in vascular cells and vessels. We used microarrays to identify the global programme of gene expression changes in mouse aortas treated with vehicle (DMSO) or aldosterone. Wild type C57Bl6 male mice were treated with spironolactone (20 mg/kg/day, an MR antagonist) for 5 days by Sub-cutaneous pellet to suppress basal MR-mediated gene expression. Aortas were then harvested and treated ex vivo in organ culture with vehicle or 100 nM aldosterone for 2, 4, or 8 hours. Three aortas were pooled for each timepoint and treatment, and three pooled biological replicates were performed.
Project description:The mineralocorticoid hormone, aldosterone, is secreted by the adrenal zona glomerulosa (ZG) in response to high plasma K+ and hypovolemia and promotes renal Na+ reabsorption and K+ secretion. Hence, the regulation of aldosterone secretion is critical for the control of ion homeostasis and blood pressure. While the kinase pathways regulating aldosterone production are well studied, little is known about the involved phosphatases. Using the human adrenocortical carcinoma cell line NCI-H295R, we found that the mRNA expression of the aldosterone synthase increases significantly within 6 hours after K+ exposure. This increase was inhibited in a dose-dependent manner by the calcineurin inhibitors tacrolimus and cyclosporine A. Calcineurin (Cn) is a serine-threonine-specific, Ca2+ and CaM-activated protein phosphatase essential for lymphocyte, neuronal and cardiac function. The physiologic role of Cn in the ZG cells and the molecular pathways by which Cn regulates the K+-stimulated secretion of aldosterone are unknown. To answer these questions, we stimulated NCI-H295R cells with K+ with or without Tacrolimus and studied the phosphorylation pattern of cytoplasmic proteins by phospho-proteomics. We generated a map of the changes in the Ser/Thr phosphorylation in adrenocortical cells upon stimulation with K+ and identified Cn-regulated phosphoproteins.
Project description:Primary aldosteronism (PA), the most common form of endocrine hypertension, is characterized by inappropriately elevated aldosterone production via renin-independent mechanisms. Driver somatic mutations for aldosterone excess have been found in approximately 90% of aldosterone-producing adenomas (APAs) using an aldosterone synthase (CYP11B2)-guided sequencing approach. Herein, using CYP11B2-guided whole-exome sequencing (WES) and targeted amplicon sequencing, we detected two closely-stationed somatic variants in SLC30A1 in five APAs (p.L51_A57del, n=3; p.L49_L55del, n=2) that were devoid of any of the known aldosterone-driver mutations. SLC30A1 encodes the ubiquitous zinc efflux transporter ZnT1 (zinc transporter 1). PA cases with SLC30A1 mutations showed male dominance and demonstrated increased serum aldosterone concentration compared with age-matched male controls. We tested functional effects of the variant SLC30A1L51_A57del in a doxycycline-inducible system using the human adrenocortical HAC15 cell line. Functional in vitro studies following doxycycline treatment indicated increased adrenal cell aldosterone production, CYP11B2 mRNA expression, CYP11B2 promoter activity, depolarization of the resting membrane potential and increased cytosolic Ca2+ levels in the SLC30A1L51_A57del cells. Collectively, these data support a pathological role for mutant SLC30A1 on the development of PA.