Meclizine is an agonist ligand for mouse constitutive androstane receptor (CAR) and an inverse agonist for human CAR.
The constitutive androstane receptor (CAR, NR1I3) is a key regulator of xenobiotic and endobiotic metabolism. The ligand-binding domains of murine (m) and human (h) CAR are divergent relative to other nuclear hormone receptors, resulting in species-specific differences in xenobiotic responses. Here we identify the widely used antiemetic meclizine (Antivert; Bonine) as both an agonist ligand for mCAR and an inverse agonist for hCAR. Meclizine increases mCAR transactivation in a dose-dependent manner. Like the mCAR agonist 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene, meclizine stimulates binding of steroid receptor coactivator 1 to the murine receptor in vitro. Meclizine administration to mice increases expression of CAR target genes in a CAR-dependent manner. In contrast, meclizine suppresses hCAR transactivation and inhibits the phenobarbital-induced expression of the CAR target genes, cytochrome p450 monooxygenase (CYP)2B10, CYP3A11, and CYP1A2, in primary hepatocytes derived from mice expressing hCAR, but not mCAR. The inhibitory effect of meclizine also suppresses acetaminophen-induced liver toxicity in humanized CAR mice. These results demonstrate that a single compound can induce opposite xenobiotic responses via orthologous receptors in rodents and humans.
Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
Wendong
W
Huang
Jun
J
Zhang
Ping
P
Wei
William T
WT
Schrader
David D
DD
Moore
D000818:Animals; D000932:Antiemetics / Q000494:pharmacology; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D000090702:Constitutive Androstane Receptor; D022781:Hepatocytes / Q000502:physiology*; D006801:Humans; D008468:Meclizine / Q000494:pharmacology*; D051379:Mice; D018345:Mice, Knockout; D012313:RNA / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000819:agonists / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D011994:Recombinant Proteins / Q000378:metabolism; D014157:Transcription Factors / Q000819:agonists / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D014162:Transfection
D000932:Antiemetics; D000090702:Constitutive Androstane Receptor; C000716327:NR1I3 protein, human; C000716328:Nr1i3 protein, mouse; D018160:Receptors, Cytoplasmic and Nuclear; D011994:Recombinant Proteins; D014157:Transcription Factors; D008468:Meclizine; D012313:RNA