PT  - JOURNAL ARTICLE
AU  - Marc Le Vee
AU  - Philippe Gripon
AU  - Bruno Stieger
AU  - Olivier Fardel
TI  - Down-Regulation of Organic Anion Transporter Expression in Human Hepatocytes Exposed to the Proinflammatory Cytokine Interleukin 1β
AID  - 10.1124/dmd.107.016907
DP  - 2008 Feb 01
TA  - Drug Metabolism and Disposition
PG  - 217--222
VI  - 36
IP  - 2
4099  - http://dmd.aspetjournals.org/content/36/2/217.short
4100  - http://dmd.aspetjournals.org/content/36/2/217.full
SO  - Drug Metab Dispos2008 Feb 01; 36
AB  - Interleukin (IL) 1β is a proinflammatory cytokine known to markedly alter expression of major organic anion transporters in rodent hepatocytes. However, its effects toward human hepatic transporters remain poorly characterized. Therefore, the present study was aimed at determining IL-1β effects on expression of organic anion transporters in primary human hepatocytes and highly differentiated human hepatoma HepaRG cells. Exposure to 1 ng/ml IL-1β was first shown to markedly repress mRNA expression of sodium-taurocholate cotransporting polypeptide (NTCP), a major sinusoidal transporter handling bile acids, in both human hepatocytes and HepaRG cells. It concomitantly reduced NTCP protein levels and NTCP-mediated cellular uptake of taurocholate in HepaRG cells. Other transporters such as the influx transporters organic anion transporting polypeptide (OATP)-B, OATP-C, and OATP8 and the efflux pumps multidrug resistance-associated protein (MRP) 2, MRP3, MRP4, and breast cancer resistance protein were also down-regulated at mRNA levels in human hepatocytes treated by IL-1β for 24 h, and most of these transporters were similarly repressed in IL-1β-exposed HepaRG cells; the cytokine also reduced bile salt export pump (BSEP) and OATP-C protein expression in human hepatocytes. IL-1β was further shown to activate the extracellular signal-regulated protein kinase (ERK) in human hepatocytes and HepaRG cells; however, chemical inhibition of this kinase failed to counteract repressing effects of IL-1β toward NTCP, BSEP, OATP-B, and OATP-C. Taken together, these data indicate that IL-1β treatment reduced expression of major organic anion transporters in human hepatic cells in an ERK-independent manner. Such IL-1β effects may likely participate in both cholestasis and alterations of hepatic detoxification pathways caused by inflammation in humans. The American Society for Pharmacology and Experimental Therapeutics