RT Journal Article
SR Electronic
T1 Induction of Drug Metabolism: The Role of Nuclear Receptors
JF Pharmacological Reviews
JO Pharmacol Rev
FD American Society for Pharmacology and Experimental Therapeutics
SP 649
OP 673
DO 10.1124/pr.55.4.2
VO 55
IS 4
A1 Handschin, Christoph
A1 Meyer, Urs A.
YR 2003
UL http://pharmrev.aspetjournals.org/content/55/4/649.abstract
AB Induction of drug metabolism was described more than 40 years ago. Progress in understanding the molecular mechanism of induction of drug-metabolizing enzymes was made recently when the important roles of the pregnane X receptor (PXR) and the constitutive androstane receptor (CAR), two members of the nuclear receptor superfamily of transcription factors, were discovered to act as sensors for lipophilic xenobiotics, including drugs. CAR and PXR bind as heterodimeric complexes with the retinoid X receptor to response elements in the regulatory regions of the induced genes. PXR is directly activated by xenobiotic ligands, whereas CAR is involved in a more complex and less well understood mechanism of signal transduction triggered by drugs. Most recently, analysis of these xenobiotic-sensing nuclear receptors and their nonmammalian precursors such as the chicken xenobiotic receptor suggests an important role of PXR and CAR also in endogenous pathways, such as cholesterol and bile acid biosynthesis and metabolism. In this review, recent findings regarding xenosensors and their target genes are summarized and are put into an evolutionary perspective in regard to how a living organism has derived a system that is able to deal with potentially toxic compounds it has not encountered before.