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594 VON WILLEBRAND FACTOR LEVELS AND VARIATIONS IN THE VON WILLEBRAND FACTOR GENE INDEPENDENTLY INFLUENCE LIVER STIFFNESS: THE ROTTERDAM STUDY
POSTERS (72±19% vs. 52±11%; p = 0.040) rats. Protein expression of VEGFR2 was significantly reduced in splanchnic tissue (p = 0.049) and in the liver (p = 0.006) of BDL animals. No significant differences in splanchnic or hepatic protein expression were observed for VEGF (p = 0.304, p = 0.118), TNFa (p = 0.215, p = 0.164) or PDGFb (p = 0.43, p = 0.18). In BDL rats, splanchnic (p = 0.007) and hepatic (p = 0.048) PlGF mRNA expression was significantly reduced by LENA treatment. In BDL, a reduction of VEGF-mRNA levels in splachnic tissue (p = 0.012) and the liver (p = 0.082) was observed. LENA treatment did not influence TNFa or PDGFb mRNA expression in BDL rats, neither in splanchnic tissue nor in the liver. In PPVL animals splanchnic protein expression of CD31 was significantly decreased (p = 0.003), while TNFa was increased (p = 0.044). Conclusion: Lenalidomide ameliorates portal hypertensive syndrome in cirrhotic and non-cirrhotic portal hypertensive rats by decreasing proinflammatory and antiangiogenic signaling. Therefore, lenalidomide has some potential as a novel therapeutic option in cirrhotic patients with portal hypertension. 594 VON WILLEBRAND FACTOR LEVELS AND VARIATIONS IN THE VON WILLEBRAND FACTOR GENE INDEPENDENTLY INFLUENCE LIVER STIFFNESS: THE ROTTERDAM STUDY E.P.C. Plompen1 , J.N.L. Schouten1 , M.P.M. de Maat2 , B.E. Hansen1,3 , A. Hofman4 , A.G. Uitterlinden4,5 , B.H.C. Stricker4 , F.W.G. Leebeek2 , H.L.A. Janssen1 . 1 Gastroenterology and Hepatology, 2 Hematology, 3 Public Health, 4 Epidemiology, 5 Internal Medicine, Erasmus MC University Medical Center, Rotterdam, The Netherlands E-mail: [email protected] Background and Aims: Hypercoagulability is considered to be one of the causative factors of liver fibrogenesis. Elevated von Willebrand factor (VWF) levels are known to increase the risk of thrombosis, but the relationship with liver fibrosis is unknown. Aim of the current study was to investigate the association between VWF levels, its genetic determinants and liver stiffness measurements (LSM) in a population-based cohort and in a subgroup of participants with non alcoholic fatty liver disease (NAFLD). Methods: This study was based on the Rotterdam study, a large population-based cohort among subjects aged ≥55 years. Transient elastography was used to assess hepatic fibrosis. NAFLD was diagnosed with abdominal ultrasound. VWF antigen levels were determined in plasma with an enzyme-linked immunosorbent assay. Ten polymorphisms known to strongly affect VWF levels were studied. Genotyping was performed with the Infinium HumanHap 550K chip. Results: Reliable LSM and genetic data were available in 1037 participants (age 74.1±5.6 years; 50.7% males). Median LSM was 5.1 kPa (IQR 4.2–6.4). Median VWF antigen level was 1.11 IU/ml (IQR 0.86–1.42). NAFLD was diagnosed in 331 participants (31.9%). VWF levels were associated with LSM in the total cohort and in a NAFLD subgroup (p = 0.001 and 0.007 respectively). rs9390459, rs687621 and rs1063857 were associated with VWF levels in the total cohort after correction for age and sex in an additive genetic model (p-values 0.034/<0.001/0.004 respectively). For genotype AA versus AG/GG at two polymorphisms located in the VWF gene, rs216321 and rs2283333, higher LSM were observed (p = 0.012 and 0.017 respectively). After adjustment for age, sex, NAFLD, spleen size, HOMA-IR and ALT, this relationship remained significant for rs2283333 (p = 0.046). A trend towards significance was observed for genotype AA versus AG/GG at rs216321 after adjustment for these factors (p = 0.097). In participants with NAFLD a third polymorphism located in the VWF gene, rs1063857, was significantly associated with LSM in a multivariate additive genetic model (p = 0.019).
Conclusions: In this population-based cohort and in a NAFLD subgroup VWF levels and three polymorphisms located in the VWF gene were independently associated with LSM. These results suggest that VWF levels may play a causal role in liver fibrogenesis. 595 ALKALINE PHOSPHATASE IS A PROTECTIVE ENZYME DURING LIVER FIBROGENESIS M. Schippers, E. Post, A. Cetintas, C. Reker-Smit, L. Beljaars, K. Poelstra. Dept. Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands E-mail: [email protected] Background and Aim: Serum alkaline phosphatase (AP) levels serve as a marker for many liver diseases. Recent studies indicate that AP may act as a protective enzyme by dephosphorylation of LPS because dephosphorylation blocks toxicity of this product. Gut-derived LPS is known to aggravate liver damage and fibrosis and we hypothesized that higher levels of AP may represent a physiological response upon higher levels of this toxin during fibrosis. We therefore studied hepatic expression levels and effects of intestinal AP during fibrogenesis. Methods: Intestinal AP knock-out C57BL/6 mice (iAP KO) were examined at 6 weeks of age and compared to age-matched wildtype. Liver fibrogenesis was induced by CCl4 administration to Balb/c mice for 1 day (acute studies) or 8 weeks (chronic studies). The latter group received saline or calf-intestinal AP (5 units, i.v.), from week 6 to 8 (3x/week, n = 6/group). Results: iAP KO mice displayed higher intrahepatic expression levels of fibrogenic markers (PAR-1, Collagen I) paralleled by an increase in macrophages of the pro-fibrotic M2 phenotype relative to WT. So, lack of intestinal AP stimulates fibrogenesis within the liver. We subsequently examined intrahepatic AP expression in normal mice, after CCl4-induced acute liver damage and after chronic CCL4 administration, characterized by liver fibrosis. Results show a gradual increase in intrahepatic AP-activity from normal to fibrotic animals. Histochemical analysis revealed that this APactivity is able to dephosphorylate the lipid A moiety of LPS. We further explored the role of AP by injecting iAP to mice with CCL4-induced fibrosis. Data show a reduced hepatic AP activity, paralleled by significant lower expression levels of desmin and significant lower accumulation of M2 macrophages in iAP-treated mice compared to control. Conclusions: Based on the increased hepatic fibrogenic activity in intestinal AP-KO mice, and the attenuated fibrogenesis in fibrotic mice receiving intestinal AP, we conclude that iAP attenuates fibrosis. The enhanced expression of AP in fibrotic livers and the demonstration that this AP activity is able to dephosphorylate LPS, suggests that endogenous AP serves as a protective enzyme after liver damage. Enhanced AP activity during disease may therefore reflect a physiological response to LPS. 596 TARGETING OF LYSYL OXIDASE-LIKE-2 (LOXL2) PROMOTES REVERSAL OF LIVER FIBROSIS VIA INHIBITION OF COLLAGEN CROSS-LINKING AND FIBROTIC MATRIX STABILIZATION N. Ikenaga1 , S. Yoshida1 , S.B. Liu1 , J. Chung1 , D. Sverdlov1 , D. Marshall2 , V. Smith2 , M. Kovalenko2 , S. Karnik2 , N. Afdhal1 , Y. Popov1 . 1 Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 2 Gilead Sciences, Inc., Foster City, CA, USA E-mail: [email protected] Background and Aims: We have previously shown that transglutaminase-independent progressive collagen cross-linking and stabilization retards liver fibrosis reversal and presents a promising target for antifibrotic therapies. Here, we tested whether collagen cross-linking can be successfully inhibited to halt and/or
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Conclusions: In this population-based cohort and in a NAFLD subgroup VWF levels and three polymorphisms located in the VWF gene were independently associated with LSM. These results suggest that VWF levels may play a causal role in liver fibrogenesis. 595 ALKALINE PHOSPHATASE IS A PROTECTIVE ENZYME DURING LIVER FIBROGENESIS M. Schippers, E. Post, A. Cetintas, C. Reker-Smit, L. Beljaars, K. Poelstra. Dept. Pharmacokinetics, Toxicology and Targeting, University of Groningen, Groningen, The Netherlands E-mail: [email protected] Background and Aim: Serum alkaline phosphatase (AP) levels serve as a marker for many liver diseases. Recent studies indicate that AP may act as a protective enzyme by dephosphorylation of LPS because dephosphorylation blocks toxicity of this product. Gut-derived LPS is known to aggravate liver damage and fibrosis and we hypothesized that higher levels of AP may represent a physiological response upon higher levels of this toxin during fibrosis. We therefore studied hepatic expression levels and effects of intestinal AP during fibrogenesis. Methods: Intestinal AP knock-out C57BL/6 mice (iAP KO) were examined at 6 weeks of age and compared to age-matched wildtype. Liver fibrogenesis was induced by CCl4 administration to Balb/c mice for 1 day (acute studies) or 8 weeks (chronic studies). The latter group received saline or calf-intestinal AP (5 units, i.v.), from week 6 to 8 (3x/week, n = 6/group). Results: iAP KO mice displayed higher intrahepatic expression levels of fibrogenic markers (PAR-1, Collagen I) paralleled by an increase in macrophages of the pro-fibrotic M2 phenotype relative to WT. So, lack of intestinal AP stimulates fibrogenesis within the liver. We subsequently examined intrahepatic AP expression in normal mice, after CCl4-induced acute liver damage and after chronic CCL4 administration, characterized by liver fibrosis. Results show a gradual increase in intrahepatic AP-activity from normal to fibrotic animals. Histochemical analysis revealed that this APactivity is able to dephosphorylate the lipid A moiety of LPS. We further explored the role of AP by injecting iAP to mice with CCL4-induced fibrosis. Data show a reduced hepatic AP activity, paralleled by significant lower expression levels of desmin and significant lower accumulation of M2 macrophages in iAP-treated mice compared to control. Conclusions: Based on the increased hepatic fibrogenic activity in intestinal AP-KO mice, and the attenuated fibrogenesis in fibrotic mice receiving intestinal AP, we conclude that iAP attenuates fibrosis. The enhanced expression of AP in fibrotic livers and the demonstration that this AP activity is able to dephosphorylate LPS, suggests that endogenous AP serves as a protective enzyme after liver damage. Enhanced AP activity during disease may therefore reflect a physiological response to LPS. 596 TARGETING OF LYSYL OXIDASE-LIKE-2 (LOXL2) PROMOTES REVERSAL OF LIVER FIBROSIS VIA INHIBITION OF COLLAGEN CROSS-LINKING AND FIBROTIC MATRIX STABILIZATION N. Ikenaga1 , S. Yoshida1 , S.B. Liu1 , J. Chung1 , D. Sverdlov1 , D. Marshall2 , V. Smith2 , M. Kovalenko2 , S. Karnik2 , N. Afdhal1 , Y. Popov1 . 1 Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 2 Gilead Sciences, Inc., Foster City, CA, USA E-mail: [email protected] Background and Aims: We have previously shown that transglutaminase-independent progressive collagen cross-linking and stabilization retards liver fibrosis reversal and presents a promising target for antifibrotic therapies. Here, we tested whether collagen cross-linking can be successfully inhibited to halt and/or
Journal of Hepatology 2013 vol. 58 | S229–S407
S243