PXR and CAR: nuclear receptors which play a pivotal role in drug disposition and chemical toxicity.
Xenobiotic metabolism and detoxification is regulated by receptors (e.g., PXR, CAR) whose characterization has contributed significantly to our understanding of drug responses in humans. Technologies facilitating the screening of compounds for receptor interactions provide valuable tools applicable in drug development. Most use in vitro systems or mice humanized for receptors in vivo. In vitro assays are limited by the reporter systems and cell lines chosen and are uninformative about effects in vivo. Humanized mouse models provide novel, exciting ways of understanding the functions of these genes. This article evaluates these technologies and current knowledge on PXR/CAR-mediated regulation of gene expression.
Stanley
Lesley A
LA
Consultant in Investigative Toxicology, St. Andrews, Fife, United Kingdom.
Horsburgh
Brian C
BC
Ross
Jillian
J
Scheer
Nico
N
Wolf
C Roland
CR
D000818:Animals; D000090702:Constitutive Androstane Receptor; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D064420:Drug-Related Side Effects and Adverse Reactions / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D022781:Hepatocytes / Q000378:metabolism; D006801:Humans; D000077297:Pregnane X Receptor; D018160:Receptors, Cytoplasmic and Nuclear / Q000502:physiology*; D011987:Receptors, Steroid / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*; D015262:Xenobiotics / Q000493:pharmacokinetics*
D000090702:Constitutive Androstane Receptor; D000077297:Pregnane X Receptor; D018160:Receptors, Cytoplasmic and Nuclear; D011987:Receptors, Steroid; D014157:Transcription Factors; D015262:Xenobiotics; D003577:Cytochrome P-450 Enzyme System