Ligand-dependent contribution of RXRbeta to cholesterol homeostasis in Sertoli cells.
Fiche publication
Date publication
mars 2004
Auteurs
Membres identifiés du Cancéropôle Est :
Pr CHAMBON Pierre
Tous les auteurs :
Mascrez B, Ghyselinck NB, Watanabe M, Annicotte JS, Chambon P, Auwerx J, Mark M
Lien Pubmed
Résumé
We show that mice expressing retinoid X receptor beta (RXRbeta) impaired in its transcriptional activation function AF-2 (Rxrb(af20) mutation) do not display the spermatid release defects observed in RXRbeta-null mutants, indicating that the role of RXRbeta in spermatid release is ligand-independent. In contrast, like RXRbeta-null mutants, Rxrb(af20) mice accumulate cholesteryl esters in Sertoli cells (SCs) due to reduced ABCA1 transporter-mediated cholesterol efflux. We provide genetic and molecular evidence that cholesterol homeostasis in SCs does not require PPARalpha and beta, but depends upon the TIF2 coactivator and RXRbeta/LXRbeta heterodimers, in which RXRbeta AF-2 is transcriptionally active. Our results also indicate that RXRbeta may be activated by a ligand distinct from 9-cis retinoic acid.
Référence
EMBO Rep. 2004 Mar;5(3):285-90.