Bile acidinduced death in primary mouse hepatocytes was independent of Nod2, suggesting that hepatoprotection from cholestasis CHIR 99021 was not mediated via Nod2 in hepatocytes. Notably, in bile duct ligated Nod2-/- mice the hepatic bile acid concentration was lower and the urinary concentration was higher than in wild type mice, providing an explanation for the protection of Nod2mice from cholestasis-induced liver injury. Following bile duct ligation Nod2-/- mice the bile acid efflux transporters MRP2 and MRP4 in the kidney were increased. Consistent with this, administration

of the Nod2 ligand MDP, caused a decrease in renal mRNA levels of MRP2 and MRP4 in wild type mice, while no inhibitory effect was observed in Nod2 deficient mice. The effect of MDP on renal MRP2 and MRP4 expression was exerted through IL-1 p release, because blocking IL-1 p signaling with the IL-1 receptor antagonist Anakinra abolished MDP-mediated downregulation of MRP2 and MRP4 in vivo. 5-Fluoracil Also, IL-1 p treatment resulted in a

marked reduction of MRP2 and MRP4 mRNA expression in a proximal tubular epithelial cell line from normal human kidney and in wild type mice in vivo. We also confirmed that IL-1 p mRNA and protein expression were lower in the kidney of Nod2-/- mice as compared to wild type mice following bile duct ligation for 3 weeks. Conclusion: These findings indicate that Nod2 deficiency protects mice from cholestatic liver injury and fibrosis through enhancing renal excretion of bile acids, which lowers intrahepatic concentrations of bile acids. Thus, the Nod2 appears to be involved in the regulation of renal tubular transport function. Disclosures: Alan F. Hofmann – Consulting: Albireo Chorioepithelioma Pharma,

Lumena Pharma, Intercept Pharma, GSK; Stock Shareholder: Intercept Pharma The following people have nothing to disclose: Lirui Wang, Phillipp Hartmann, Michael Haimerl, Sai P. Bathena, Yazen Alnouti, Bernd Schnabl Recent studies indicate that the intracellular adhesion molecule, ICAM-1, is induced in mouse liver after bile duct ligation (BDL). ICAM-1 plays a key role in neutrophil extravasation across the endothelial barrier as well as neutrophil binding to hepatocytes, two major steps in neutrophil-dependent inflammation which is a predominant inflammatory response associated with liver injury after BDL. ICAM-1 has been shown to interact with ezrin, a member of the ezrin-radixin-moesin (ERM) family of cytoskeletal proteins that also interact with the PDZ protein, Na+/H+ exchanger regulatory factor 1(NHERF-1/EBP50). ERM knockdown reduces ICAM-1 expression in response to the proinflammatory cytokine tumor necrosis factor-a. Aims: To determine whether deficiencies in NHERF-1 may affect hepatic radixin and ICAM-1 expression and, therefore, neutrophil accumulation in the liver after BDL.