An ADIOL-ERβ-CtBP Transrepression Pathway Negatively Regulates Microglia-Mediated Inflammation

Microglia and astrocytes play essential roles in the maintenance of homeostasis within the central nervous system, but mechanisms that control the magnitude and duration of responses to infection and injury remain poorly understood. Here, we provide evidence that 5-androsten-3 beta, 17 beta-diol (ADIOL) functions as a selective modulator of estrogen receptor (ER)beta to suppress inflammatory responses of microglia and astrocytes. ADIOL and a subset of synthetic ER beta-specific ligands, but not 17 beta-estradiol, mediate recruitment of CtBP corepressor complexes to AP-1-dependent promoters, thereby repressing genes that amplify inflammatory responses and activate Th17 T cells. Reduction of ADIOL or ER beta expression results in exaggerated inflammatory responses to TLR4 agonists. Conversely, the administration of ADIOL or synthetic ER beta-specific ligands that promote CtBP recruitment prevents experimental autoimmune encephalomyelitis in an ER beta-dependent manner. These findings provide evidence for an ADIOL/ER beta/CtBP-transrepression pathway that regulates inflammatory responses in microglia and can be targeted by selective ER beta modulators.