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sconfirmed by HE, red-sirius and Masson's trichrome staining, in parellel with the reductionof TNFα, IL-6, TGF-β1 and TIMP-1. Moreover, In Vitro study indicated that HNF1α coulddirectly enhance the transcriptional expression and the phosphatase activity of the Srcdomain-containing phosphatase-1 (SHP-1). Blocking the activity of SHP-1 could suppressethe effect of HNF1α in both hepatocytes and HSCs. In conclusion, up-regulation of HNF1αmay present as a promising strategy for the treatment of hepatic fibrosis. The anti-fibroticeffect of HNF1α is at least partly attributed to the up-regulation of SHP-1 in hepatocytesand hepatic stellate cells.

Su1594

Regulation and Function of Methionine Adenosyltransferases in Quiescent andActivated Human Hepatic Stellate CellsSunhee Park, Maria Lauda Tomasi, Komal Ramani

Background and Aim: Liver injury triggers activation of hepatic stellate cells (HSC). Thesechanges involve modulation of key regulators of the genome. Methionine adenosyltransferases(MAT) catalyze the formation of the methyl donor, S-adenosylmethionine (SAMe). Mamma-lian cells express two kinds of MAT genes MAT1A and MAT2A that encode for catalyticsubunits. A third gene MAT2B encodes a regulatory subunit that regulates the MAT2Aencoded isoenzyme. MAT1A is expressed in adult hepatocytes, but not in HSCs. Both MAT2Aand MAT2B are expressed in extrahepatic tissues and in de-differentiated liver. They arealso expressed in normal HSCs. In human cells, two functional variants of the MAT2B genehave been described, namely MAT2B-V1 and V2. Recently we showed that both MAT2Aand MAT2B are induced during HSC activation in the bile duct ligation (BDL) rat modelsof liver fibrosis. In humanHSCs we showed that silencingMAT genes blocked HSC activation,reduced cell growth and induced apoptosis. Knockdown of MAT2B blocked cell survivalpathways, ERK and PI3-Kinase whereas silencing MAT2A had no effect. The aim of thiswork is to understand how MAT genes are regulated in quiescent and activated humanHSCs and how they influence signaling in these cells. Methods: The activated human HSCcell line, LX-2 was treated with an adipogenic differentiation mixture (MDI) for 3 or 7 daysto induce quiescence. Quiescence was assayed either by peroxisome proliferator activatedreceptor (PPARγ) expression or cell growth by the BrDU assay. Silencing of MAT2A, MAT2BV1 and V2 was done by siRNA. MAT2A, MAT2B V1 or V2 expression was measured byreal-time PCR or western blotting. Expression of P38 MAPKinase (phospho and total) ormyocyte enhancer factor (MEF2A) was checked by western blotting. Results: MDI inducedthe adipogenic factor, PPARγ expression and reduced cell growth of LX2 cells. MAT2AmRNA expression remained unchanged in LX2 cells after MDI treatment compared tocontrol. However, MAT2B V1 mRNA level was reduced by 35% during 7 day culture inMDI. Despite no change in MAT2A mRNA expression, the MAT2A protein level droppedby 50-60% in quiescent HSCs. Silencing MAT2B V1 or V2 decreased the phosphorylationof p38MAPK by 50% compared to negative control siRNA. MAT2B V1 or V2 knockdownalso lowered the expression of MEF2A, a positive regulator of HSC activation known torequire p38MAPK for its activity. MAT2A silencing did not influence p38MAPK or MEF2Ain human HSCs. Conclusion: Our findings indicate that MAT2A protein is down-regulatedin quiescent HSCs compared to activated cells. This implies that MAT2A is controlled atthe protein level in quiescent versus activated HSCs. Functionally, MAT2B variants but notMAT2A, promote key components of HSC activation, p38MAPK and MEF2A and hencethey may provide novel therapeutic targets in human liver fibrosis.

Su1595

The Anti-Aging Protein Klotho Inhibits Hepatic Stellate Cell Activation bySuppressing the Transforming Growth Factor-β1 (TGF-β1) Signaling PathwayLiu Yang, Tamas Ordog, Vijay Shah

Background & Aims: Klotho (α-Klotho, KL) is a pleiotropic peptide with anti-aging proper-ties. Klotho expressed on the surface of cells in a limited number of tissues serves as co-receptor for fibroblast growth factor 23 and also as the source of free Klotho protein, whichcan influence the function of many organs. Recent studies suggest that Klotho suppressesrenal fibrosis in mice. Our goal in this project was to investigate the hypothesis that Klothomay also inhibit liver fibrogenesis by regulating activation of hepatic stellate cells (HSC), apivotal factor in liver fibrosis. Methods: Freshly isolated rat HSC were harvested at differenttime points during culture-induced activation. Klotho mRNA and protein expression wasevaluated by real-time RT-PCR and Western immunoblotting, respectively. cDNA encodingthe human membrane-bound (KL-M) and secreted form of Klotho (KL-S) was subclonedinto adenovirus using the AdEasy system. Smooth muscle actin (SMA) expression level inrat and human HSC was measured by Western blotting after Klotho overexpression deliveredby adenovirus (Ad-KL-M and Ad-KL-S). TGF-β-induced SMA expression was evaluated inthe presence of Ad-KL-M, KL-S, or control virus (Ad-LacZ). Results: HSC activation inculture was associated with a reduction in both Klotho mRNA (2.5 fold reduction) andprotein levels (2.3 fold reduction) when compared with quiescent cells. Adenovirus-mediatedoverexpression of either KL-M or KL-S suppressed SMA protein expression in activatedhuman HSC by 2.3 fold measured with western blot densitometry. The TGF-β-inducedSMA mRNA elevation was also abrogated by both membrane and secreted forms of klothooverexpression (Ad-LacZ:2.9 ± 0.26 vs. Ad-KL-M:1.6 ± 0.2 vs. Ad-KL-S:1.59 ± 0.2, P<0.05,N=3). Conclusions: Klotho inhibits HSC activation by suppressing the TGF-β signalingpathway. These results highlight a new regulatory mechanism and potential therapeutictarget in TGF-β-induced HSC activation and liver fibrosis.

S-974AASLD Abstracts

Su1596

Stress Induced Increased Placental IL-6 May Predict Future Onset of LiverFibrosisJorje Allina, Jacquelin Grabowski, Shannon Doherty-Lyons, Vivek Kesar, Maria Isabel Fiel,Christine Jackson, Judith Zelikoff, Joseph Odin

Background: Retrospective epidemiologic studies have suggested a relationship betweenmaternal stress during pregnancy and the development of chronic diseases in the adulthood.Cigarette smoke (CS) is perhaps the most ubiquitous and hazardous of all fetal environmentalstresses and has been associated with future onset of cardiovascular disease and diabetes.Maternal stress typically decreases offspring number and causes intrauterine growth retarda-tion due to altered placental production of insulin like growth factors (IGF) and pro-inflammatory cytokines (PIC). But relatively little is known about the effect of such fetalstressors on offspring's future onset of liver disease. Methods: CD-1 dams (pregnant mice)were either Ova albumin (OVA)-sensitized (OVA-sensitization and challenge during preg-nancy induces asthmatic responses) or challengedwith Phosphate Buffer Saline (PBS). Furtherthese dams were exposed either to filtered air (FA) or mainstream cigarette smoke (MCS)from gestational day 4 until 1 day before parturition. Thus there were 4 groups: PBS andFA (PFA), PBS and MCS (PCS), OVA and FA (OFA) and OVA and MCS (OCS). Dams fromthe 4 groups were either sacrificed immediately prior to parturition or adult offspring wereevaluated at 8 weeks of age. The unborn fetuses were enumerated, weighed, and theirplacental histology and mRNA expression (RT-PCR) of PIC were analyzed. Also, weight,hepatic histology, and mRNA expression of PIC were examined in the adult offspring. Semi-quantitative analysis of Sirius Red staining to measure liver fibrosis was also performed.Results: Increased airway hyper-reactivity and elevated IgE levels were noted in OVA exposed/challenged dams compared to PBS sensitized dams as expected. No statistically significantdifferences in the fetus number, gender, or weight were noted between any of the fourgroups. Increased hepatic fibrosis was noted only in adult male offspring whose damsbelonged to OCS group (9% of total area versus <3% in other groups) but no accompanyingincrease in hepatic inflammation and pro-fibrotic cytokine mRNA levels was seen. However,placental mRNA levels of IL-6, a pro-fibrotic cytokine, were increased 3.5±1.1 fold (p<0.05)in OCS group compared to control mice (PFA). The placental levels of other pro-fibroticcytokines, such as platelet derived growth factor, were not increased in the OCS group.OCS group was also unique as placental IGFR2 mRNA levels were not significantly alteredcompared to PFA group. Whereas PCS mice had significantly elevated IGFR2 mRNA levels(1.7+/-0.8 fold; p=0.004) and OFA mice had significantly decreased levels (1.8+/-0.4 fold;p<0.001) compared to control mice (PFA). Conclusions: Maternal stress during pregnancyis a potential risk factor for hepatic fibrosis in adult male offspring possibly related to alterplacental cytokine mRNA expression.

Su1597

Loss of Autophagy Enhances Diethylnitrosamine-Induced Liver ToxicityShunhei Yamashina, Miheguli Abudoxueke, Akira Uchiyama, Kazuyoshi Kon, KenichiIkejima, Sumio Watanabe

Background: Previous reports showed that diethylnitrosamine (DEN) treatment increasedreactive oxygen species and apoptotic response in livers of mice. High intracellular levelsof ROS can lead to damaged mitochondria, DNA modification, resulting in a number ofdisease states, including cancer. It is suggested that mitochondrial dysfunction is essentialfor the development of liver injury due to DEN. Autophagy, which is a major catabolicpathway, plays a critical role in removing protein aggregates, as well as damaged or excessmitochondria in order to maintain intracellular homeostasis. The aim of this study was toclarify if autophagy is linked to liver injury due to DEN. Methods: DEN was administeredintraperitoneally (10mg/kg) to wild type mice (Atg7F/F) and conditional Atg7-knockoutmice (Atg7F/F:Mx1-Cre), which have autophagy-deficient liver. Mice of both genotypes weresacrificed 24, 48 hours after administration of DEN. Liver tissues embedded in paraffin werecut and stained with H&E. TUNEL-staining was performed to evaluate apoptotic cells.Serum ALT value was measured to evaluate liver damage. Moreover, expression of caspase-3 and 7 were detected by Western blot analysis. Results: Serum ALT levels before administra-tion of DEN were not significantly different between Wild type mice and conditional Atg7-knockout mice. Serum ALT levels at 48 hours after administration of DEN was elevated toabout 7-fold in conditional Atg7-knockout mice but not control mice. Autophagy-deficiencyenhanced the number of TUNEL-positive cells and activation of caspase-3 and 7 in the liverafter administration of DEN. Conclusions: Our data indicates that loss of autophagy enhancedapoptosis of hepatocytes and liver injury due to DEN. These findings suggest that autophagyplays a pivotal role to prevent the excessive cell death of hepatocyte in the DEN-inducedliver injury.

Su1599

The Selective Adenosine 2B Receptor Antagonist MRS1754 Mitigates HepaticCollagen Deposition During Fibrosis Progression and Induces Mild FibrosisRegressionMatthias Stoll, Yong Ook Kim, Bernhard Hebich, Simon C. Robson, Detlef Schuppan

Background and Aims: The anti-inflammatory metabolite adenosine addresses 4 receptors,which are differentially expressed on cells. Recent studies indicate a role for specific adenosinereceptors in liver diseases, including NASH, hepatic inflammation and fibrosis. Since it isunclear how far the A2B receptor modulates fibrogenesis, we investigated the selectiveA2B receptor antagonist MRS1754 in two complementary liver fibrosis models. Methods:Spontaneously fibrotic Mdr2(-/-) mice were injected intraperitoneally daily from week 6-10of age either with vehicle (n=10), low dose MRS1754 (0.5mg/10ml 0.2%DMSO in PBS perkg, n=10), or high dose MRS1754 (2mg/10ml/kg, n=10). A second cohort of mice wastreated according to an optimized CCl4 fibrosis model (Popov Y et al, Gastroenterology2011) for 2 weeks, to receive low dose (0.5mg/kg or 2mg/kg, each n=6) MRS1754 duringthe second week, and 6 mice receiving vehicle only. In the fibrosis regression cohort after8 weeks of fibrosis induction with CCl4, mice were injected daily with the two doses of