Bisphenol A and its analogues activate human pregnane X receptor.
BACKGROUND
Bisphenol A (BPA) is a base chemical used extensively in many consumer products. BPA and its analogues are present in environmental and human samples. Many endocrine-disrupting chemicals, including BPA, have been shown to activate the pregnane X receptor (PXR), a nuclear receptor that functions as a master regulator of xenobiotic metabolism. However, the detailed mechanism by which these chemicals activate PXR remains unknown.


OBJECTIVE
We investigated the mechanism by which BPA interacts with and activates PXR and examined selected BPA analogues to determine whether they bind to and activate PXR.


METHODS
Cell-based reporter assays, in silico ligand-PXR docking studies, and site-directed mutagenesis were combined to study the interaction between BPA and PXR. We also investigated the influence of BPA and its analogues on the regulation of PXR target genes in human LS180 cells.


RESULTS
We found that BPA and several of its analogues are potent agonists for human PXR (hPXR) but do not affect mouse PXR activity. We identified key residues within hPXR's ligand-binding pocket that constitute points of interaction with BPA. We also deduced the structural requirements of BPA analogues that activate hPXR. BPA and its analogues can also induce PXR target gene expression in human LS180 cells.


CONCLUSIONS
The present study advances our understanding of the mechanism by which BPA interacts with and activates human PXR. Activation of PXR by BPA may explain some of the adverse effects of BPA in humans.
Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, Kentucky 40536, USA.
Yipeng
Y
Sui
Ni
N
Ai
Se-Hyung
SH
Park
Jennifer
J
Rios-Pilier
Jordan T
JT
Perkins
William J
WJ
Welsh
Changcheng
C
Zhou
D000818:Animals; D001559:Benzhydryl Compounds; D045744:Cell Line, Tumor; D052244:Endocrine Disruptors / Q000494:pharmacology*; D004785:Environmental Pollutants / Q000494:pharmacology; D006801:Humans; D051379:Mice; D016297:Mutagenesis, Site-Directed; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology*; D000077297:Pregnane X Receptor; D012313:RNA / Q000032:analysis; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D011987:Receptors, Steroid / Q000819:agonists* / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity; D014162:Transfection; D000098826:Bisphenol A Compounds
D001559:Benzhydryl Compounds; D052244:Endocrine Disruptors; D004785:Environmental Pollutants; D010636:Phenols; D000077297:Pregnane X Receptor; D012313:RNA; D011987:Receptors, Steroid; C006780:bisphenol A; D000098826:Bisphenol A Compounds