7α,25-dihydroxy Cholesterol

Uses

7α,25-dihydroxycholesterol has been used:

• as a G-protein-coupled receptor 183 ( GPR183) ligand in chemotaxis assay and intracellular cytokine staining method and in fluorescence-activated cell sorting (FACS) analysis of natural killer cells
• in oxysterol based calcium mobilization assay in Chinese hamster ovary (CHO) cells
• in competitive radioligand binding assay of Epstein-Barr virus-induced gene 2 (EBI2) expressing COS-7 cells

Uses

GPR183 (also known as Epstein-Barr virus-induced gene 2) is an orphan G protein-coupled receptor (GPCR) that is highly expressed in spleen and is required for humoral immune responses, including B cell migration and T cell-dependent antibody production. 7α,25-dihydroxy Cholesterol (7α,25-DHC) is a potent agonist of GPR183 that induces specific activation of the receptor with an EC50 value of 50 nM (Kd = 450 pM). At concentrations below 3 μM, it does not show any appreciable binding activity when tested against eight different nuclear hormone receptors including LXR and thirty-one different G protein-coupled receptors in a panel of reporter gene assays. 7α,25-DHC can act as a potent chemokine, affecting migration of immune cells expressing GPR183 both in vitro (EC50 = 500 pM) and in vivo.[Cayman Chemical]

Uses

3β,7α,25-Trihydroxycholest-5-ene is a potent agonist of GPR183 that induces specific activation of the receptor.

Definition

ChEBI: 7alpha,25-dihydroxycholesterol is a 7alpha-hydroxy steroid, a 25-hydroxy steroid, an oxysterol and a 3beta-hydroxy-Delta(5)-steroid. It has a role as a human metabolite. It is functionally related to a cholesterol.

General Description

7α,25-dihydroxycholesterol (7α,25-OHC) is synthesized by the hydroxylation of cholesterol by the action of enzyme cholesterol 25-hydroxylase (CH25H) and cytochrome P450, family 7, subfamily b, polypeptide 1 (CYP7B1). The catabolic breakdown of 7α,25-OHC to bile acid precursors is catalyzed by the enzymes hydroxy-Δ-5-steroid dehydrogenase, 3β- and steroid Δ-isomerase 7 (HSD3B7).

Biological Activity

7α,25-dihydroxy cholesterol (7α,25-dhc, 7α,25-ohc) is a potent and selective gpr183 agonist [1].epstein-barr virus (ebv)-induced gene 2 (ebi2, also known as gpr183) is an orphan g protein-coupled receptor that is highly expressed in spleen and up-regulated upon epstein–barr-virus infection. gpr183 is required for humoral immune responses and polymorphisms in the receptor is associated with inflammatory autoimmune diseases [1][2].7α,25-dihydroxy cholesterol is a potent and selective gpr183 (ebi2) agonist and most potent ebi2 ligand with ec50 and kd values of 140 pm and 450 pm, respectively. in a competition binding study, 7α,25-ohc competed for binding with ic50 value of 242 pm. in ebi2-expressing cells, 7α,25-ohc dose-dependently inhibited forskolin-induced camp with ic50 value of 2 nm. 7α,25-ohc was probably the endogenous ligand for ebi2. in ebi2-expressing mouse b and t cells, 7α,25-dihydroxy cholesterol stimulated cell migration with ic50 value of around 500 pm, but had no effect on ebi2-deficient cells [1].in ebi2-deficient mice, unseparated splenocytes, b cells and t cells were completely unresponsive to 7α,25-ohc stimulation [1]. mice deficient in ch25h, a key enzyme for the generation of 7α, 25-ohc, failed to position activated b cells within the spleen to the outer follicle [2].

Biochem/physiol Actions

7α,25-dihydroxycholesterol (7α,25-OHC) serves as an endogenous ligand for G-protein-coupled receptor 183 (GPR183) or Epstein-Barr virus-induced gene 2 (EBI2). It plays a key role in the migration of type 3 innate lymphoid cells (ILC3) in the small intestine and colon. 7α,25-OHC mediates immune cell migration functionality by their chemoattractant property. Inhibition of 7α,25-OHC synthesis leads to impairment in the migration of B cells.

References

[1]. liu c, yang xv, wu j, et al. oxysterols direct b-cell migration through ebi2. nature. 2011 jul 27;475(7357):519-23.
[2]. hannedouche s, zhang j, yi t, et al. oxysterols direct immune cell migration via ebi2. nature. 2011 jul 27;475(7357):524-7.