Retinoic Acid Receptor-Mediated Induction of ABCA1 in Macrophages Academic Article Article uri icon

Overview

MeSH Major

  • Autophagy
  • Leukemia, Promyelocytic, Acute
  • Receptors, Retinoic Acid

abstract

  • ABCA1, the mutant molecule in Tangier Disease, mediates efflux of cellular cholesterol to apoA-I and is induced by liver X receptor (LXR)/retinoid X receptor (RXR) transcription factors. Retinoic acid receptor (RAR) activators (all-trans-retinoic acid [ATRA] and TTNPB) were found to increase ATP-binding cassette transporter 1 (ABCA1) mRNA and protein in macrophages. In cellular cotransfection assays, RARgamma/RXR activated the human ABCA1 promoter, via the same direct repeat 4 (DR4) promoter element as LXR/RXR. Chromatin immunoprecipitation analysis in macrophages confirmed the binding of RARgamma/RXR to the ABCA1 promoter DR4 element in the presence of ATRA, with weaker binding of RARalpha/RXR, and no binding of RARbeta/RXR. However, in macrophages from RARgamma(-/-) mice, TTNPB still induced ABCA1, in association with marked upregulation of RARalpha, suggesting that high levels of RARalpha can compensate for the absence of RARgamma. Dose-response experiments with ATRA in mouse primary macrophages showed that other LXR target genes were weakly induced (ABCG1 and SREBP-1c) or not induced (apoE and LXRalpha). The more specific RAR activator TTNPB did not induce SREBP-1c in mouse primary macrophages or liver. These studies indicate a direct role of RARgamma/RXR in induction of macrophage ABCA1.

publication date

  • November 2003

Research

keywords

  • Academic Article

Identity

Digital Object Identifier (DOI)

  • 10.1128/MCB.23.21.7756-7766.2003

PubMed ID

  • 14560020

Additional Document Info

start page

  • 7756

end page

  • 66

volume

  • 23

number

  • 21