FRI-075 Platelet-derived growth factor receptor alpha deprived hepatocytes attenuate thioacetamide induced liver fibrosis in mice J.II. Lee 1 , K.S. Lee 1 , H.W. Lee 1 , W.-K. Lee 2 , H.Y. Chang 3 . 1 Yonsei University College of Medicine, Internal Medicine, Seoul, Korea, Rep. of South; 2 Inha Univeristy College of Medicine, Biomedical Sciences, Incheon, Korea, Rep. of South; 3 Gangnam Severance Hospital, Medical Research Center, Seoul, Korea, Rep. of South Email: mdflorence@yuhs.ac Background and Aims: Platelet-derived growth factor receptor (PDGFR)-alpha expression is very low in normal liver. It dramatically increases in cirrhotic liver where activated hepatic stellate cells (HSCs) are suggested to be responsible for this increment. Although normal hepatocytes scarcely express PDGFR-alpha, cancerous hepa- tocytes may have up-regulated PDGFR-alpha expression. Since hepatocellular carcinoma is very often preceded by liver fibrosis, we hypothesized that upon repetitive liver insult, PDGFR-alpha on abnormal hepatocytes might play an important role in liver fibrosis by means of cell-to-cell crosstalk between hepatocytes and HSCs. Method: Hepatocytes were isolated from normal and thioacetamide (TAA) induced cirrhotic liver respectively for assessment of PDGFR- alpha expression on hepatocytes. Then, we generated conditional knock-out mice from C57BL/6 mice where PDGFR-alpha was deleted on hepatocytes. Liver fibrosis was induced by injecting TAA for 8 weeks. Hep3B cells were transfected with siRNA (PDGFR-alpha or control) and co-cultured with LX2 cells. Results: PDGFR-alpha expression was increased on hepatocytes from cirrhotic liver compared with that from normal liver. After PDGFR- alpha on hepatocytes was deleted, TAA induced liver fibrosis was significantly attenuated in mice. Although expressions of transform- ing growth factor beta and Smad2/3 were enhanced after deletion of hepatocyte PDGFR-alpha, this was compensated by increased inhibitory Smad7 expression, resulting in decreased liver fibrosis. From the co-culture system, LX2 cells, cultured with PDGFR-alpha siRNA infected Hep3B cells, showed decreased PDGFR-alpha expres- sion as well as attenuated alpha-smooth muscle actin (SMA) and collagen 1 (Col1) alpha expression. Conclusion: Deleting PDGFR-alpha on hepatocytes resulted in attenuated TAA induced liver fibrosis. This suggests that although PDGFR-alpha is scarcely expressed on normal hepatocytes, in the event of chronic liver injury, PDGFR-alpha on hepatocytes plays an important role, facilitating liver fibrosis. FRI-076 Platelet deactivation attenuates CCL4 induced liver fibrosis progression in mice A. Bhat 1 , S. Mg 1 , A. Parasar 1 , A. Rastogi 2 , S.K. Sarin 1,3 . 1 ILBS, Molecular and cellular medicine, New Delhi, India; 2 ILBS, Department of Histopathology, New Delhi, India; 3 ILBS, Department of Hepatology, New Delhi, India Email: shivsarin@gmail.com Background and Aims: Platelet activation induces liver fibrosis by PDGF-B dependent fibrogenic activation of hepatic stellate cells, and use of aspirin significantly attenuates the liver fibrosis progression by deactivating platelets in the animal model. The aim of this study is to further investigate the molecular mechanism of platelet deactivation by aspirin in liver fibrogenesis. Method: Forty-two male C57/B6 mice were randomly divided into the control group (n = 7), ASA group (n = 7), CCL4 group (n = 14), and CCL4 + ASA group (n = 14). CCL4-induced fibrotic mice received 0.5μl/ g bw of 50% carbon tetrachloride (CCL4) by intraperitoneal injection i.p. twice a week for 10 weeks while two different doses of Aspirin were given in drinkingwater. We compared the liver injury in both low (5mg/kg) and the moderate dose (50mg/kg) post euthanization after 10 weeks. Both hematoxylin-eosin and Masson’s trichrome staining were performed to observe pathological changes in liver tissue. Liver fibrosis was evaluated by histology, biochemical determination of liver enzymes, collagen content and QRT-PCR. Results: The aspirin-treated group displayed a decrease in platelet counts as compared to the control groups. Further, Alanine aminotransferase, aspartate aminotransferase, and total bilirubin were found to be higher in CCL4 group as compared to the aspirin- treated group. Assessment of Hepatic fibrosis by METAVIR score showed a significant decline in fibrotic areas and hydroxyproline contents in the aspirin-treated group as compared to CCL4 group (p < 0.01). Moreover, usage of aspirin at moderate-doses significantly improved the long-term fibrosis outcomes in the CCL4 model of liver fibrosis. Platelet deactivation by aspirin revealed a significant correlation with the expression levels of collagen type I as well as alpha-smooth muscle actin, a marker of HSC activation. Quantitative RT-PCR results revealed a downregulation of PDGFR expressions in the aspirin-treated group as compared to the CCL4 model group. Figure 1 Hepatoprotective effect of platelet inhibition in CCl4 induced hepatic injury. (A) Representative photomicrographs of liver histology from normal healthy mice, ASA alone, CCl4 + vehicle alone and CCl4 + ASA. Mice were given repeated injections of CCl4 for 10 weeks in CCL4 model group. (B-E)Platelet number, Serum aminotransferases, direct and total bilirubin levels are plotted. Grading of hepatic fibrosis was evaluated on a scale of 1–4 as follows: 1, scattered; 2, mild; 3, moderate and 4, marked. The histological changes were assessed in 200× magnification fields of slides stained with H&E and Masson’s trichrome. Conclusion: Platelets may promote fibrosis during liver injury and pharmacological targeting of platelet activation could be beneficial and strongly attenuate fibrosis progression. FRI-077 Combination of an FXR agonist and an ACC inhibitor increases anti-fibrotic efficacy in rodent models of NASH J. Bates, D. Hollenback, A. Zagorska, G. Budas, J. Liles, H. Liu, K. Liu, S. Kusam, R. Brockett, D. Newstrom, I. Mikaelian, T. Wang, A. Ray, D. Breckenridge. Gilead Sciences, Inc., Research, Foster City, United States Email: jamie.bates@gilead.com Background and Aims: GS-9674 a selective, non-steroidal Farnesoid X Receptor (FXR) agonist (FXRag), and GS-0976, a liver-directed Acetyl-CoA Carboxylase (ACC) inhibitor (ACCi), are currently being investigated in clinical trials for NASH. FXR activation inhibits bile acid synthesis, and increases bile salt export. ACC 1 and 2 catalyze the rate limiting step of de novo lipogenesis (DNL) and inhibit mitochondrial fatty acid oxidation (FAO), respectively, which is hypothesized to promote lipotoxicity in NASH. We evaluated the potential efficacy of combination therapy agonizing FXR and inhibiting ACC in rodent models of NASH. Method: Male C57BL/6 mice were administered a fast food diet (FFD) enriched in fat, cholesterol, and sugar for 6 months and treated with vehicle, FXRag, ACCi, or FXRag + ACCi from months 5 to 6 (n = 14–16/ group). Endpoints included quantification of hepatic triglycerides (TG), plasma ALT, and hepatic gene expression by NanoString (Col1a1 and Timp1). Male Wistar Han rats were fed a choline deficient high fat diet (CDHFD) for 12 weeks and administered vehicle, FXRag, ACCi, or FXRag + ACCi from week 6 to 12 (n = 15–16/group). Fibrosis and fibroplasia were assessed by picrosirius red (PSR) staining and α-SMA POSTERS PRESENTATIONS S395 Journal of Hepatology 2018 vol. 68 | S365–S604