38 SERUM METABOLOMIC PROFILING IN PATIENTS WITH CHOLESTATIC PRURITUS

ORAL PRESENTATIONS mice. As functional consequence of hepatic alterations in bile acid metabolism less cytotoxic hydrophilic bile acids are reduced and may contribute to a more toxic bilary environment by hydrophobic bile acids. The study supports the “toxic bile concept” in the pathogenesis of IBD-associated biliary disease. 38 SERUM METABOLOMIC PROFILING IN PATIENTS WITH CHOLESTATIC PRURITUS A. Pares1 , M. Perez-Cormenzana2 , R. Mayo2 , A. Bennasar1 , A. Mas1 , A. Castro2 . 1 Liver Unit, Hospital Clinic de Barcelona, IDIBAPS, CIBERehd, University of Barcelona, Barcelona, 2 OWLGenomics, Bilbao, Spain E-mail: [email protected] Background and Aims: Pruritus is a common and disabling symptom in chronic cholestasis. The pathogenesis of this symptom is unknown but recently it has been associated with increased levels of lysophosphatidic acid. The role of other potential molecules is unknown, and therefore we have evaluated the serum metabolomic profile of patients with cholestatic pruritus. Methods: Serum samples were obtained from 36 female patients with primary biliary cirrhosis (PBC), 12 with severe pruritus, and 24 without pruritus, and from 10 healthy controls. All patients received ursodeoxycholic acid (13–15 mg/kg/d) for the duration of the disease which was similar in the two groups (8.3±1.4 years). Metabolite extraction was accomplished by fractionating the serum samples into pools of species with similar physicochemical properties. All samples were randomized prior to the metabolite extraction procedure and three different profiles were used: a) polar lipids, non-esterified fatty acids, and bile acids; b) amino acids, and c) apolar lipids. The analyses were performed by UPLC-ESI-QTOFMS, random forests and multivariate data analysis. Results: Around 400 metabolites were identified in serum from patients with PBC. Patients with pruritus had significantly higher content of ceramides (p < 0.001), lysophosphatidylcholines (p = 0.03), phosphatidylcholines (p = 0.04), and triglycerides (p < 0.05) than patients without pruritus. Moreover, the detailed analysis of the lipid profile identified that patients with pruritus had higher levels of most lysophosphatidylcholines and phosphatidylcholines and lower contents of lysophosphatidylethanolamines and phosphatidylethanolamines. The serum level of ceramides, sphingomyelins and diacylglycerophosphoinositol was higher in patients with pruritus as well. No difference in the amino acid profile was observed between the two groups. The overall content of bile acids was not significantly different between patients with and without pruritus. However, a more detailed analysis observed higher amounts of glycocholic and taurocholic acid (p < 0.03), and lower levels of ursodeoxycholic and hyocholic acid (p < 0.05) in patients with pruritus. Conclusion: The metabolomic profile of patients with cholestatic pruritus is characterized by a marked change in the lipid metabolites, particularly in the ceramides, sphingomyelins and lysophospahtidylcholines. The analysis identified a panel of biomarkers that could effectively participate into the pathogenesis of pruritus.

Parallel Session: PRE-CLINICAL HBV & HCV

39 EPIGENETIC CONTROL OF HEPATITIS B VIRUS REPLICATION AND FARNESOID X RECEPTOR ALPHA EXPRESSION BY HISTONE DEACETYLASES 3 X. Zhang1 , H. Liu1,2 , B. Wang3 , Z. Ma1 , J. Zhang2 , D. Yang3 , J. Schlaak4 , M. Roggendorf1 , M. Lu1 . 1 Institute of Virology, University Hospital of Essen, University of Duisburg-Essen, Essen, Germany; 2 Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, 3 Department of Infectious Disease, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China; 4 Department of Gastroenterology and Hepatology, University Hospital of Essen, University of Duisburg-Essen, Essen, Germany E-mail: [email protected] Background and Aims: Recent studies on the epigenetic modulation of HBV cccDNA function indicated that HBV replication was regulated by the acetylation status of cccDNA-bound H3 and H4 histones. Histone acetylation is a dynamic process controlled by histone deacetylases (HDAC) enzyme activity. HDAC inhibition induces the hyperacetylation of nucleosomal histones, resulting in the expression of repressed genes. Considering our previous finding that HDACs were involved in the regulation of HBV replication by miRNAs, the role of the individual HDACs in the regulation of HBV replication were investigated in the present study. Methods: HBV replication and gene expression were examined by southern blot and specific ELISA after silencing or over-expression of different HDACs. The cellular gene expression profiles and phenotypic change in hepatocytes were analyzed by microarray, real time RT-PCR, proliferation assay, and FACS cell cycle analysis. Results: Specific siRNAs were used to knock down the expression of different HDAC genes. Silencing of HDAC3 resulted in the strongest increase of HBV antigen expression and replication in HepG2.2.15 cells. Consistently, HDAC3 over-expression significantly inhibited HBV replication and gene expression in Huh7 cells in transiently transfection assays. Microarray analysis of the global cellular gene expression profiles revealed that farnesoid X receptor a (FXRA) expression and genes related to hepatocytes differentiation were induced by HDAC3 knockdown. The findings by microarrays were further confirmed by real time RT-PCR. In addition, HDAC3 knockdown inhibited cell proliferation and G1/S cell cycle transition. Immunohistochemical staining of HCC sections with HBV infection revealed an inverse correlation of HDAC3 expression levels and FXRA and HBcAg expression in malignant and peritumoral liver tissue. Conclusions: These data indicated the control of HBV replication and FXRA expression by HDAC3 at the transcription level and the potential risk of HBV reactivation in HCC patients treated with HDAC inhibitors. 40 HLA-B27 HAS A DOMINANT ROLE IN RESTRICTING STRONG CD8+ T CELL RESPONSES AND DRIVING VIRAL ESCAPE IN HEPATITIS B VIRUS INFECTION M.M. Kiraithe1,2 , K. Nitschke1 , D. Price3 , E. Gostick3 , H.E. Blum1 , R. Thimme1 , C. Neumann-Haefelin1 . 1 Medicine II, University of Freiburg, Freiburg im Breisgau, Germany; 2 International Master Program in Biomedical Sciences, University of Buenos Aires, Buenos Aires, Argentina; 3 Department of Infection, Immunity and Biochemistry, University of Cardiff, Cardiff, UK E-mail: [email protected] Background and Aims: Important insights into the immunobiology of HIV and HCV infection have been derived from the study of

Journal of Hepatology 2012 vol. 56 | S1–S20

S17