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sMo2034

Altered Composition of Fatty Acids Exacerbates Hepato-Tumorigenesis UnderActive Phosphatidylinositol 3-Kinase PathwayYotaro Kudo, Yasuo Tanaka, Keisuke Tateishi, Keisuke Yamamoto, Shinzo Yamamoto,Hayato Nakagawa, Yoshinari Asaoka, Motohisa Tada, Hideaki Ijichi, Tsuneo Ikenoue, ShinMaeda, Fumihiko Kanai, Masao Omata, Kazuhiko Koike

Nonalcoholic fatty liver disease as well as nonalcoholic steatohepatitis is regarded as a soilof hepatocellular carcinoma (HCC), however the molecular mechanisms linking metabolicdysfunction to oncogenesis is not fully elucidated. Dysregulated phosphatidylinositol 3-kinase (PI3K)/Akt pathway is implicated both in metabolic dysfunction and carcinogenesisin humans, however, it remains unknown whether the altered metabolic status caused byabnormal activation of the pathway is linked to the pro-tumorigenic effect or not. It isreported that the PIK3CA gene encoding p110alpha that is a catalytic subunit of PI3K hasa somatic mutation in HCC. We established hepatocyte-specific Pik3ca transgenic mice,harboring a mutation N1068fs*4 reported in HCC. The Pik3ca transgenic mice demonstratedboth hepatic steatosis and tumor development without inflammation or fibrosis. The peroxi-some proliferator-activated receptor gamma-dependent lipogenesis was accelerated in thePik3ca transgenic liver and the abnormal profile of fatty acids composition was seen in thetumors from Pik3ca transgenic liver. In addition, the enhanced activation of the PI3K/Aktpathway and decreased expression of tumor suppressor genes including Pten, Xpo4 and Dlc1were demonstrated in the tumors. Interestingly, we found that the In Vitro colony formationof immortalized hepatocytes was enhanced by the treatment of oleic acid that was accumulatedin the tumors. Also it was suggested that the expression of tumor suppressor genes isrepressed by oleic acid treatment in an epigenetic manner. These findings indicated thatunusual fatty acids-induced cellular signaling and epigenetic change can promote In Vivohepato-tumorigenesis under the constitutively active PI3K pathway. Our data might be aclue addressing the molecular mechanisms how metabolic dysfunction contributes to InVivo tumor progression.

Mo2035

Pharmacological Therapy of Nonalcoholic Steatohepatitis-Systematic ReviewMariko Hojo, Akihito Nagahara, Daisuke Asaoka, Hitoshi Sasaki, Sumio Watanabe

[Backgrounds and aims] Non alcoholic fatty liver disease consists of a spectrum of disordersranging from simple steatosis to nonalcoholic steatohepatitis (NASH) and cirrhosis. NASH,unlike simple steatosis, is a potentially progressive disease. Various types of drugs have beenexplored for the treatment of NASH. To determine the therapeutic value of these treatments,we performed a systematic review of research reports in which their efficacy in the treatmentof NASHwas evaluated based on liver biopsy results. [Methods] Studies on the pharmacother-apy of NASH published up to August 2010 were retrieved from PUBMED and their referencelists were examined to identify additional relevant publications. Studies in which the particip-ants were at least 19 years old and in which biopsies were evaluated at baseline and at theend of treatment were selected from the retrieved articles and used in the analysis. [Results]Thirty-three articles including 45 treatment arms were selected from 455 articles retrievedthrough our literature search. Of the 36 selected articles, 11 were double-blind randomizedcontrolled trials (RCTs). The majority of the selected studies had a treatment duration of48 weeks. A total of 9 studies included 50 or more subjects. In 31 of 40 treatment armsthe grade of histologic features other than fibrosis was significantly improved, and in 11 of36 treatment arms the stage of liver fibrosis was significantly improved. Although significantimprovement of liver fibrosis was reported in most of the studies on pioglitazone, theseresults were not confirmed in a recent a large-scale RCT. To date, no drug treatment hasyet been reliably proven in large-scale RCTs to improve hepatic fibrosis in NASH. [Conclu-sion] Due to a lack of large-scale, high quality, long-term clinical trials, the utility of anyparticular treatment for NASH is not yet clear.

Mo2036

Genetic Expression of Inflammatory Markers in Patients With Fatty LiverAngela C. Martino, Nayan S. Patel, Arseima Y. Del Valle-Pinero, Wendy A. Henderson

Background & Aim: Fatty liver, a growing epidemic, is a common cause of chronic liverdisease with multiple co-morbidities including obesity, hyperlipidemia, insulin resistance,diabetes, and metabolic syndrome. Currently, there is an unmet need in identification ofindividuals with an increased risk of developing fatty liver disease. This study describesgenetic expression of inflammatory related genes as potential clinical markers of fatty liver.Methods: Patients recruited to a natural history protocol underwent fasting screening meas-ures (blood-work, plethysmography, anthropometrics, abdominal ultrasound); incidentally,four patients had fatty liver. Genetic expression was evaluated on these patients and comparedto age, gender, and race matched controls. The sample mean age is 32 ± 8.55 years (range22-45), 50% male, 100% Caucasian. Blood was collected peripherally via PAXgene tubes.RNA was extracted using the PAXgene™ Blood miRNA kit, Qiagen. RNA quantity andquality was verified. RT2 first strand synthesis was performed to obtain cDNA. RT2 Profiler™PCR Array Human Inflammatory plate was run using Applied Biosystems 7900HT. Geneticexpression of 87 genes was determined using SABiosciences PCR Array Data Analysis(www.sabiosciences.com). Further statistical and pathway analysis were completed usingSPSSv15 and IPA8.8, respectively. Two-fold change boundary was set a priori to be consideredsignificant. All patients gave informed consent. Results: Dysregulation of three inflammatorygenes was found in patients with fatty liver compared to healthy controls. Chemokine C-C motif ligand 8 (CCL8, -2.0522 fold), chemokine C-X-C motif ligand 10 (CXCL10, -2.0112fold), nitric oxide synthase 2 (NOS2, -2.7053 fold) were all downregulated compared tocontrols. Fatty liver patients had significantly higher serum insulin (p = .035; 17.2 ± 9.75mcU/mL vs. 3.6 ± 2.36 mcU/mL); intra-abdominal height (p = .004; 13.2 ± 1.61 cm vs.7.8 ± 1.78 cm); percent body fat (p = .010; 40.3 ± 9.62% vs. 18.8 ± 6.43%, and BMI (p =.007; 35.5 ± 7.28 vs. 20.5 ± 1.54) compared to controls. There were no significant differencesbetween the groups with regard to serum alanine aminotransferase or other serologicalindexes. Conclusions: These findings support potential relationships between inflammatory

S-704AGA Abstracts

genes, obesity, and insulin in fatty liver. NOS2 is an inducible cytokine of the NOS familywhich is indirectly moderated by various cytokines. NOS2 is a factor responsible for synthesisof nitric oxide which is important in preventing ischemic liver damage. Therefore, in obeseindividuals, downregulation of NOS2 coupled with insulin resistance may impact fattyliver disease.

Mo2038

Objective Assessment of Aerophagia During Meals in Normal Subjects andPatients With Post-Prandial Bloating and BelchingPhilip Woodland, Ravinder S. Gill, Jafar Jafari, Ivana Bravi, Ryuichi Shimono, AsmaFikree, Jamal Hayat, Tatenda Marunda, Albert J. Bredenoord, Etsuro Yazaki, Daniel Sifrim

Many patients attending GI physiology units for assessment of dysphagia and reflux symptomsalso complain of post-prandial bloating and/or belching. Using esophageal impedance mon-itoring excessive air swallowing (aerophagia) between meals has recently been observed inpatients with severe continuous bloating and belching. Exaggerated air swallowing duringmeals might be more relevant for post-prandial symptoms but, thus far, has not been studied.We aimed to quantify air swallowing during meals in asymptomatic subjects and patientswith post-prandial bloating and belching. Methods: We assessed air swallowing duringmeals using ambulatory impedance-pH tracings of 39 healthy, asymptomatic controls (fromthe US-Belgian MII-pH Normal value study, Shay et al. 2004, mean age in study 39, range22-62) to establish normal 95% confidence intervals. We identified 38 patients (mean age43, range 17-74) with post-prandial bloating and/or belching who attended the GI physiologyunit for assessment of dysphagia or reflux symptoms. Symptomswere established by question-naire prior to investigation. Mealtime air swallows were visually identified when swallowswere associated with antegrade flow and fast impedance increase (at least 3000Ω abovebaseline level) in the most distal recording segment. A score of air swallows, normalizedper 10min mealtime, was calculated for each subject. In patients with mealtime exaggeratedair swallowing (above 95th percentile of normal values) the presence of concomitant fastingaerophagia was assessed. Results: The 95% percentile range of mealtime air swallowing innormal subjects was 6.8 to 9.4 episodes/10 min, mean 8.1. Patients had significantly highermealtime air swallowing rates than controls (mean 11.8 episodes/10 min, SEM 1.0, p=0.003). There was no significant difference between predominant bloating and belchingsubgroups. 23 out of 38 patients (61%) displayed air swallowing above 95th percentile ofnormal values, and only 4 of these had concomitant fasting aerophagia. Conclusion: Weestablished normal values of mealtime air swallowing using esophageal impedance. We showthat exaggerated air swallowing during meals can now be objectively detected. A group ofpatients with post-prandial bloating and/or belching exhibit increased air swallowing duringmeals, a behavior that could potentially be modified using biofeedback techniques.

Mo2039

Suppression of Antioxidants Gene Expression by Genetic Deletion of NRF2Reduces In Vivo Nitrergic Function and Delays Gastric EmptyingPandu R. Gangula, Kalpana Ravella, Konjeti R. Sekhar, Michael L. Freeman, GianricoFarrugia, Keith M. Channon, Ashley B. Hale

Background: Emerging research suggests that antioxidant gene expression has the potentialto suppress the development of gastroparesis. We used mice carrying a targeted disruptionof Nrf2, the transcription factor that directs antioxidant Phase II gene expression or of Gclm,the modifier subunit for glutamate-cysteine ligase, to test the hypothesis that defectiveantioxidant gene expression contributes to development of gastroparesis. Methods: 12-14week-old female homozygous (-/-) nrf2-KOmice (C57BL6J/SV129) and their wild-type (WT)littermates (+/+) were used in this study. Functional and biochemical studies were performedusing standardized protocols. Results: Delayed gastric emptying (p<0.05) was observed inNrf2-KO mice (42.0±5.19 % vs. 57.0±1.57 %). In Vitro studies on gastric muscular tissuesshowed a decrease (p<0.05) in NO release in Nrf2-KO mice (1.0±0.06 vs. 1.67±0.22 μmole/mg tissue). In addition, nitrergic relaxation was impaired in Nrf2-KO mice (-0.07±0.03 vs.-0.22±0.04 AUC/mg tissue; p<0.05). Surprisingly, Nrf2 null mice displayed increased (p<0.05)gastric nNOSα protein expression and dimerization. There was however down regulationof the phase II enzymes glutamate-cysteine ligase modifier subunit (Gclm) and catalyticsubunit (Gclc) as well as antioxidant enzymes catalase and superoxide dismutase (p<0.05).Gclm-/- mice demonstrated that loss of glutamate-cysteine ligase function enhanced tetrahy-drobiopterin oxidation while impairing nitrergic relaxation (-0.14±0.02 vs. -0.43±0.06 AUC/mg tissue). Conclusion: These results demonstrate that defects in antioxidant gene expressioncan result in tetrahydrobiopterin oxidation, impaired nitrergic signaling and provide supportfor the hypothesis that oxidative stress can contribute to the development of gastroparesis.Grant Support: P60DK020593 pilot project funds (PG), RCMI G12RR03032 provided toPG and NIH/NCI RO1CA115556 (MLF).