Glucocorticoid Receptor (GR)

What is the Glucocorticoid Receptor (GR)?

The glucocorticoid receptor (GR) is a critical transcription factor that regulates immune responses, stress responses, and metabolism. Its interactions with glucocorticoid hormones and synthetic glucocorticoids have significant therapeutic implications, especially in the management of inflammatory and autoimmune disorders. The ongoing interest in GR as a drug discovery target seeks to develop improved therapies with enhanced efficacy and reduced side effects.

GR’s Role in Disease

The glucocorticoid receptor (GR) is a member of the nuclear receptor superfamily, which functions as a ligand-activated transcription factor. GR is widely expressed in various tissues and plays a vital role in regulating immune responses, stress responses, and metabolism. In its inactive state, GR resides in the cytoplasm as part of a multiprotein complex. Upon binding to glucocorticoid hormones, such as cortisol, GR undergoes a conformational change, translocates to the nucleus, and binds to specific DNA sequences known as glucocorticoid response elements (GREs). This interaction leads to the modulation of target gene transcription, influencing a wide range of physiological processes. In the absence of activated GR, other transcription factors such as NF-κB or AP-1 themselves can transactivate target genes. However activated GR can complex with these other transcription factors and prevent them from binding their target genes and hence repress the expression of genes that are normally upregulated by NF-κB or AP-1. This indirect mechanism of action is referred to as transrepression. Endogenous glucocorticoids, such as cortisol in humans and corticosterone in rodents, serve as natural ligands for GR.

GR’s Role in Drug Discovery

Interest in GR as a drug discovery target stems from its pivotal role in regulating immune responses and inflammation. Exogenous can be associated with severe side effects, including bone loss, glucocorticoids, such as prednisone and dexamethasone, are synthetic drugs used to treat various inflammatory and autoimmune conditions due to their potent anti-inflammatory and immunosuppressive properties. Synthetic glucocorticoids have been extensively used for decades in the management of inflammatory and autoimmune disorders, but their long-term use weight gain, and impaired glucose metabolism. Researchers are actively working to develop novel glucocorticoid receptor ligands that retain the beneficial anti-inflammatory effects while minimizing adverse effects. For example, CORT118335 is an investigational glucocorticoid receptor modulator being developed by Corcept Therapeutics for the treatment of Cushing’s syndrome and other metabolic disorders. It has been shown to selectively modulate GR activity to reduce cortisol production while avoiding off-target effects.

INDIGO’s GR Reporter Assays

INDIGO Biosciences offers cell-based luciferase reporter assay kits for the Glucocorticoid Receptor. Our assays provide an all-inclusive luciferase reporter system that includes, in addition to GR Reporter Cells, optimized media for use during cell culture and in diluting the user’s test samples, a reference agonist, Luciferase Detection Reagent, and a cell culture-ready assay plate. INDIGO can also perform the GR assay in its own lab as a service for researchers.

INDIGO’s cell-based reporter assays allow scientists to screen and discover drugs that can be used to treat GR-related diseases. They provide an efficient way to examine a compound for its ability to regulate nuclear receptor activity in agonist, inverse-agonist, or antagonist mode using firefly luciferase reporter gene technology. Since the receptor binding controls the expression of the luciferase reporter gene, luciferase activity in the cells can be correlated directly with the activity of the receptor. Contact us today to learn more about our Glucocorticoid Receptor assay kits and screening capabilities!