SUMOylation of pregnane X receptor suppresses rifampicin-induced CYP3A4 and P-gp expression and activity in LS174T cells.

Tan H¹, Xu C², Zeng H¹, Wang Y¹, Li Y³, Fan X¹, Chen P³, Jiang Y¹, Chen X³, Huang M⁴, Bi H⁵.

Author information

1Laboratory of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, Guangdong 510006, China.2Department of Pharmacy, School of Medicine, Shenzhen University, Shenzhen, Guangdong 518060, China.3Department of Pharmacy, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, China.4Laboratory of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, Guangdong 510006, China. Electronic address: huangmin@mail.sysu.edu.cn.5Laboratory of Drug Metabolism and Pharmacokinetics, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, Guangdong 510006, China. Electronic address: bihchang@mail.sysu.edu.cn.

Abstract

The pregnane X receptor (PXR) has been well-established as a critical mediator in regulating important drug metabolizing enzymes and transporter proteins, including cytochrome P450 3A4 (CYP3A4) and P-glycoprotein (P-gp). Previous studies identified that PXR served as a molecular target of SUMOylation. However, the impact of SUMOylation of PXR on its transcriptional activity in regulating the expression/activity of the target genes is poorly investigated. In the current study, we established cell-based models of SUMOylated PXR in LS174T cells to investigate the impact of SUMOylation of PXR on regulating the expression/activity of CYP3A4 and P-gp. Our results revealed that rifampicin-induced PXR transactivation of the CYP3A4 and P-gp promoter was suppressed by SUMOylation of PXR in reporter gene assay. The mRNA and protein expression of CYP3A4 and P-gp was also suppressed. Moreover, CYP3A4 enzymatic assay and Rho123 intracellular assay revealed that rifampicin-induced CYP3A4 and P-gp activity was also suppressed by SUMOylated PXR. Our data collectively indicated for the first time that SUMOylation of PXR exerts suppressive effect on rifampicin-induced expression and activity of CYP3A4 and P-gp, which suggest that alteration in the SUMOylation status of PXR will be expected to affect the CYP3A4 mediated drug metabolism and P-gp mediated drug transport.

KEYWORDS:

CYP3A4; P-gp; Pregnane X receptor; SUMOylation; Transcriptional activity