Interleukin-6 negatively regulates the expression of pregnane X receptor and constitutively activated receptor in primary human hepatocytes.
The marked impairment of hepatic drug metabolism during inflammation and infections has been known for many years and shown to result from down-regulation of cytochrome P450s (CYP) by cytokines. However, the mechanism of this repression is unknown. Using primary cultures of human hepatocytes, we show here that interleukin-6 (IL-6) rapidly and markedly decreases the expression of PXR (pregnane X receptor) and CAR (constitutively activated receptor) mRNAs, but does not affect the levels of dioxin receptor and glucocorticoid receptor mRNA. In parallel, IL-6 decreases both rifampicin- and phenobarbital-mediated induction of CYP2B6, CYP2C8, CYP2C9, and CYP3A4. As the transcriptional activity of PXR and CAR is not affected by IL-6 in cell-based reporter assays, our data suggest that the loss of CYP2 and CYP3 inducibility results from the negative regulation of PXR and CAR gene expression by this cytokine.
INSERM U128, IFR24, 1919 Route de Mende, Montpellier, 34293, France.
J M
JM
Pascussi
S
S
Gerbal-Chaloin
L
L
Pichard-Garcia
M
M
Daujat
J M
JM
Fabre
P
P
Maurel
M J
MJ
Vilarem
D002478:Cells, Cultured; D000090702:Constitutive Androstane Receptor; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D015536:Down-Regulation; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism / Q000494:pharmacology*; D008099:Liver / Q000378:metabolism*; D000077297:Pregnane X Receptor; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D011987:Receptors, Steroid / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors
D000090702:Constitutive Androstane Receptor; D015850:Interleukin-6; D000077297:Pregnane X Receptor; D018160:Receptors, Cytoplasmic and Nuclear; D011987:Receptors, Steroid; D015534:Trans-Activators; D014157:Transcription Factors; D003577:Cytochrome P-450 Enzyme System