Mineralocorticoid Receptor (MR; NR3C2)
These Mineralocorticoid Receptor Reporter Assay Systems utilize non-human mammalian cells engineered to express human NR3C2 protein, commonly referred to as MR.
The mineralocorticoid receptor (MR), also called aldosterone receptor, is a receptor with high affinity for mineralocorticoids. It belongs to the steroid hormone receptor family where the ligand diffuses into cells, interacts with the receptor, and results in a signal transduction affecting specific gene expression in the nucleus. The gene for the NR3C2 (located on chromosome 4q31.1-31.2) encodes for the 107 kDa MR protein.
MR is expressed in many tissues, such as the kidney, colon, heart, central nervous system (hippocampus), brown adipose tissue, and sweat glands. In epithelial tissues, its activation leads to the expression of proteins regulating ionic and water transports (mainly the epithelial sodium channel or ENaC, Na+/K+ pump, serum and glucocorticoid induced kinase or SGK1) resulting in the reabsorption of sodium, and as a consequence an increase in extracellular volume, increase in blood pressure, and an excretion of potassium to maintain a normal salt concentration in the body.
The receptor is activated by mineralocorticoids such as aldosterone and deoxycorticosterone as well as glucocorticoids, like cortisol and cortison. It also responds to some progestins. Spironolactone and eplerenone are mineralocorticoid receptor antagonists. Activation of the mineralocorticoid receptor, upon the binding of its ligand aldosterone, results in its translocation to the cell nucleus, homodimerization and binding to hormone response elements present in the promoter of some genes. This results in the complex recruitment of the transcriptional machinery and the transcription into mRNA of the DNA sequence of the activated genes.
For more information on MR, visit the Nuclear Receptor Resource.
Kits are offered in different assay formats to accommodate researchers’ needs: 3x 32, 1x 96, and 1x 384 assay formats for screening small numbers of test compounds, as well as custom bulk reagents for HTS applications. Assay systems are all inclusive, providing reporter cells, optimized growth media, media for diluting test compounds, a positive-control agonist, luciferase detection reagent, a white assay plate, a detailed protocol, and a protocol quick guide. All kits are shipped on dry ice.
MR Reporter Cells are prepared using INDIGO’s proprietary CryoMite™ process. This cryo-preservation method yields high cell viability post-thaw, and provides the convenience of immediately dispensing healthy, division-competent reporter cells into assay plates. There is no need for intermediate spin-and-wash steps, viability determinations, or cell titer adjustments.
The principle application of this assay product is in the screening of test samples to quantify functional activities, either agonist or antagonist, that they may exert against the human mineralocorticoid receptor. This kit product is an all-inclusive assay system that includes, in addition to MR Reporter Cells, two optimized media for use during cell culture and (optionally) in diluting the test samples, a reference agonist, Luciferase Detection Reagent, a cell culture-ready assay plate, and a detailed protocol.
| Product Family | Product Number | Product Description |
| IB0050 MR (NR3C2) | IB00501-32 | Human MR Reporter Assay System, 3 x 32 assays in 96-well format |
| IB00501 | Human MR Reporter Assay System, 1 x 96-well format assays | |
| IB00502 | Human MR Reporter Assay System, 1 x 384-well format assays |
Service Assays: Human
The primary application of INDIGO’s cell-based nuclear receptor assays are to quantitatively assess the bioactivity of a test compound as an agonist (activator) or antagonist (inhibition of an agonist response) of a given receptor. Service assays include a positive control reference compound and ‘vehicle’ control for every experiment. A formal study report and all data files are provided to the client upon completion of the study. To receive a quote for your proposed study, complete & submit the online “Request a Quote” form or contact an INDIGO Customer Service Representative to discuss your desired study parameters. To initiate a Service Study, download and complete all fields of the Excel worksheet “Service Work Order" then submit the electronic file to INDIGO Customer Service.
Biotransformation of the mineralocorticoid receptor antagonists spironolactone and canrenone by human CYP11B1 and CYP11B2: Characterization of the products and their influence on mineralocorticoid receptor transactivation
ABSTRACT Spironolactone and its major metabolite canrenone are potent mineralocorticoid receptor antagonists and are, therefore, applied as drugs for the treatment of primary aldosteronism and essential hypertension. We report that both compounds can be converted by the purified adrenocortical cytochromes P450 CYP11B1 and CYP11B2, while no conversion of the selective mineralocorticoid receptor antagonist eplerenone wasRead More
Spironolactone blocks Epstein-Barr virus production by inhibiting EBV SM protein function
ABSTRACT Clinically available drugs active against Epstein–Barr virus (EBV) and other human herpes viruses are limited to those targeting viral DNA replication. To identify compounds directed against other steps in the viral life cycle, we searched for drugs active against the EBV SM protein, which is essential for infectious virus production. SM has a highlyRead More
Inhibition of aldosterone synthase (CYP11B2) by torasemide prevents atrial fibrosis and atrial fibrillation in mice
ABSTRACT Loop diuretics are used for fluid control in patients with heart failure. Furosemide and torasemide may exert differential effects on myocardial fibrosis. Here, we studied the effects of torasemide and furosemide on atrial fibrosis and remodeling during atrial fibrillation. In primary neonatal cardiac fibroblasts, torasemide (50 μM, 24 h) but not furosemide (50 μM, 24 h) reduced theRead More