POSTERS P0943 BENEFICIAL EFFECTS OF IL-1 CYTOKINE INACTIVATION AND THE ROLE OF THE SERINE/THREONINE KINASE MK-2 IN HEPATIC STEATOSIS IN A MURINE OBESITY MODEL J. Wohlfahrt 1 , A. Fettelschoss 2 , T. K¨ undig 2 , H. Hermanns 3 , B. M¨ ullhaupt 4 , J. Schmitt 1 , A. Geier 1 . 1 Division of Hepatology, University Hospital W¨ urzburg (UKW), W¨ urzburg, Germany; 2 Department of Dermatology, University Hospital Z¨ urich (USZ), Z¨ urich, Switzerland; 3 Rudolf-Virchow-Zentrum for experimental Biomedicine, University W¨ urzburg, W¨ urzburg, Germany; 4 Department of Gastroenterology and Hepatology, University Hospital Z¨ urich (USZ), Z¨ urich, Switzerland E-mail: wohlfahrt_j@ukw.de Background and Aims: Although non-alcoholic fatty liver disease (NAFLD) is among the most common causes of chronic liver disease worldwide, its pathogenesis is yet poorly understood. Recent studies show that IL-1a/b play a crucial role in disease development. Their recognition by cells does not only result in transcriptional regulation of many IL-1 target genes, but also negatively affects cell surface expression of the IL-6 signal transducer in an MK-2 (mitogen-activated protein kinase-activated protein kinase 2)- dependent mechanism. Therefore the cells might become less susceptible for IL-6 signalling, which is suspected to be beneficial in steatosis. We aim to investigate the role of IL-1 in early steatosis in IL-1-immunized and MK-2 deficient mice. Methods: C57BL/6J wild-type and MK-2 deficient mice were fed a Surwit High Fat Diet (HFD) for 8 weeks; for inactivation of IL-1 mice were subcutaneously vaccinated against IL-1a/b using virus- like particles presenting antigens of IL-1a/b (Cytos-Biotechnology). Liver and fat tissue was analysed and RNA was isolated to assess gene expression via qPCR. Results: Our recent findings show that inactivation of IL-1 by virus- like particles drastically reduces steatosis in mice fed a HFD for 6 weeks on a macroscopic and molecular level. Lipid accumulation is drastically reduced and lipogenic enzyme as well as proinflamma- tory molecule expression is significantly downregulated. Although no cytokine expression is detectable in the liver at such an early timepoint expression levels are elevated in adipose tissue of animals fed a HDF. IL-1b serum levels show no differences between chow- or HFD-fed mice, pointing towards an indirect effect of fatty tissue inflammation on the liver. MK-2 deficient mice show no significant differences in liver weight or expression of any inflammatory markers in qPCR after 8 weeks of feeding. Conclusions: Our results strongly support future studies on IL-1 for clinical applications since its inactivation prevents liver steatosis in HFD-fed mice. The present study indicates that the main initial target site for IL-1 is the adipose tissue rather than the liver itself. Therefore, the effect on the liver appears to be indirect as IL-1b serum levels do not increase upon feeding mice a HFD. Furthermore, MK-2 deficient mice fed a HFD for 8 weeks show no difference in liver inflammation in comparison to WT mice, indicating that the IL-1/IL-6 cross-talk does not affect the early phase of steatosis. P0944 MODULATION OF MUSCLE MICRORNA EXPRESSION PROFILES IN PATIENTS WITH NAFLD AND IN C2C12 CELLS INCUBATED WITH PALMITIC ACID A.L. Sim˜ ao 1 , M.B. Afonso 1 , P.M. Rodrigues 1 , A.J. Amaral 2 , M. Gama- Carvalho 2 , P.M. Borralho 1 , M.V. Machado 3,4 , H. Cortez-Pinto 3,4 , C.M.P. Rodrigues 1 , R.E. Castro 1 . 1 Research Institute for Medicines (iMed.ULisboa), 2 BioFIG – Center for Functional and Integrative Genomics, 3 Gastrenterology, Hospital Santa Maria, 4 IMM, Faculty of Medicine, Universidade de Lisboa, Lisbon, Portugal E-mail: adlsimao@ff.ul.pt Background and Aims: In the skeletal muscle, non-alcoholic fatty liver disease (NAFLD) associates with intramyocellular lipid deposition, mitochondrial dysfunction and insulin resistance (IR), particularly in obese patients. Further, recent evidences support a functional role for microRNAs (miRNA/miRs) in regulating muscle mitochondrial impairment and IR. Finally, tauroursodeoxycholic acid (TUDCA) is cytoprotective in both liver and muscle cells, in part, by stabilizing mitochondria. Our aims were to profile global muscle miRNA expression profiles from patients at different NAFLD stages and validate their role, as well as of TUDCA, in insulin- resistant muscle cells. Methods: Muscle and matching liver biopsies were obtained from morbid obese NAFLD patients undergoing bariatric surgery. Muscle RNA was run in TaqMan MicroRNA arrays. qPCR array data was analyzed using the HTqPCR package in Bioconductor. Differential expression analysis was performed with interquantile range values >1.5 using the lmfit function of the Limma package and the Benjamini-Hochberg conditional hypergeometric test algorithm. C2C12 cells were incubated with or without palmitic acid (PA), in the presence or absence of TUDCA, for characterization of the insulin signaling pathway, as well as mitochondrial and overall cellular toxicity. Results: Our results show a progressive and significant increase in the expression of 6 muscle miRNAs from steatosis to more severe NASH (at least p < 0.05). These included miR-339-3p, which has been described to regulate glucose synthesis, and miR-361, found increased in type II diabetes (T2D) patients serum. Inversely, 8 miRNAs were decreased (at least p < 0.05), including miR-20b, reported as down-regulated in T2D patients plasma. Incubation of C2C12 cells with PA inhibited the insulin-signaling pathway, while increasing mitochondrial dysfunction and apoptosis (at least p < 0.05), all of which were prevented by co-incubation of cells with TUDCA (p < 0.05). Of note, miR-339-3p was also increased by PA (p < 0.05), targeting MAPK phosphatase-7 (MKP-7), a negative regulator of JNK, thus likely contributing for IR. Conclusions: In conclusion, our results indicate that miRNAs associated with T2D and mitochondrial dysfunction are differently modulated with NAFLD severity in the muscle, with miR-339-3p arising as a novel mechanistic player. In addition, TUDCA attenuates muscle cells IR and lipoapoptosis and, as such, may ameliorate NAFLD-associated muscle dysfunction. Supported by PTDC/BIM-MEC/0873/2012, FCT, Portugal. P0945 SURGICAL REMOVAL OF INFLAMED EPIDIDYMAL WHITE ADIPOSE TISSUE OF OBESE C57BL6/J MICE ATTENUATES THE DEVELOPMENT OF NON-ALCOHOLIC STEATOHEPATITIS P.C. Mulder 1 , M. Morrison 1 , T. Kooistra 1 , H. van Bockel 2 , P. Wielinga 1 , R. Kleemann 1 . 1 Metabolic Health Research, TNO, 2 Vascular surgery, LUMC, Leiden, Netherlands E-mail: petra.mulder@tno.nl Background and Aims: Non-alcoholic fatty liver disease (NAFLD) and the development of its severe form non- alcoholic steatohepatitis (NASH) is strongly associated with abdominal obesity. It has been postulated that obesity-associated inflammation in abdominal white adipose tissue (WAT) contributes to this relationship. To investigate whether inflamed WAT plays a causal role in the pathogenesis of NAFLD, we surgically removed the inflamed abdominal (epididymal) WAT of obese mice (with established steatosis) and investigated further progression of NAFLD towards NASH. Methods: Male C57BL/6J mice were fed a high-fat diet (HFD) for 12 weeks to develop obesity with inflammation in epididymal WAT (eWAT) and liver steatosis. Subsequently, surgical removal of inflamed eWAT (WATx) or a SHAM procedure was performed and mice continued on HFD for another 12 weeks. NAFLD development was analyzed histologically and by RT-PCR. Journal of Hepatology 2015 vol. 62 | S263–S864 S699