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T1618 Eicosapentaenoic Acid Suppresses Steatohepatitis and Hepatocellular Carcinoma in a Mouse Model of Nonalcoholic Steatohepatitis
T1616
species (ROS) was also determined. Forty- and 76-week-old mice were used in tumor burden experiments. Results: EPA improved hepatic steatosis in Pten-deficient mice based on decreased expression of AMPKα1-mediated SREBP-1c and increased PPARα expression. The EPA group exhibited less severe chronic hepatic inflammation compared to the control group, resulting from decreased ROS formation and a dramatically low ratio of arachidonic acid to EPA. Moreover, EPA inhibited development of hepatocellular carcinoma (HCC) in Pten-deficient mice based on an inhibition of MAPK activity and a low ratio of oleic to stealic acid, and a reduction in ROS formation. Conclusions: EPA suppressed steatohepatitis and development of HCC in Pten-deficient mice. We propose EPA as a potent therapeutic reagent of human NASH.
AASLD Abstracts
Pan-Caspase Inhibitor VX-166 Reduces Fibrosis in An Animal Model of NonAlcoholic Steatohepatitis Rafal P. Witek, Walter C. Stone, Gamze F. Karaca, John Pollard, Peter Charlton, Anna Mae Diehl Background: Nonalcoholic Fatty Liver Disease (NAFLD) is a potentially progressive liver disease that culminates in cirrhosis in some individuals. Cirrhosis occurs more often in individuals with nonalcoholic steatohepatitis (NASH) than in those with steatosis (NAFL). A major difference between NAFL and NASH is the extent of hepatocyte apoptosis, which is much more extensive in NASH. Phagocytosis of apoptotic cells is known to activate hepatic stellate cells (HSC) to a myofibroblastic phenotype. Thus, we examined the hypothesis that a pan-caspase inhibitor, VX-166, would reduce progression of fibrosis in a mouse model of NASH. Methods: 8-10-week old obese, male C57/BL6 db/db mice were fed Methionine Choline Deficient (MCD) diets (n=35) to induce NASH and liver fibrosis. Controls (n=35) were fed normal chow. In each group, 25 mice were gavaged once daily with the pancaspase inhibitor VX-166 (6mg/kg/d; Vertex; Abingdon, UK) in Poly-ethylene glycol (PEG), and remaining 10 mice received PEG only. In each group half of the mice were sacrificed at 4 weeks and half at 8 weeks. At sacrifice, liver tissue and serum were collected and assessed for liver injury (ALT, NAS score), caspase 3 activity, triglycerides, and fibrosis (collagen 1α1 and α-Smooth Muscle Actin (αSMA)) by biochemical assays, western blot (WB) and qRT-PCR. Results: Chow-fed db/db mice had NAFL. MCD caused NASH and fibrosis in db/db mice. WB revealed that MCD also increased caspase 3 activity. Treatment of MCD-fed db/db mice with VX-166 decreased active caspase 3 by 2-fold at 4 weeks (p<0.05) and 0.5 fold at 8 weeks (p<0.05). Results were confirmed by IHC. Liver histology showed that VX-166 treatment decreased steatosis; hepatic triglyceride content was also lower than controls (p<0.05). ALT levels were similar in control and VX-166-treated MCD-fed db/db mice. Histology confirmed that both groups had liver injury (NAS≥4). Nevertheless, treatment of MCD-fed db/db mice with VX-166 significantly reduced αSMA expression (WB, 2-fold reduction at 4 weeks, p<0.05; 3-fold reduction at 8 weeks, p<0.005), and collagen 1α1 mRNA levels (one-fold reduction at 8 weeks, p<0.05). Histology confirmed decreases in αSMA and fibrosis. Conclusion: Inhibiting hepatic apoptosis reduced accumulation of αSMA and suppressed development of fibrosis in obese mice with diet-induced NASH. Beneficial effects on liver fibrosis were associated with reductions in hepatic steatosis, but occurred without obvious improvement in liver injury. The observations are consistent with evidence that apoptosis triggers HSC activation and liver fibrosis, and suggest that caspase inhibitors may be useful as an anti-fibrotic therapy in NASH.
T1619 Alteration in Hepatic Innate Immunity Triggers Hepatic Regeneration Failure in Obese and Diabetic Kk-aY Mice Tomonori Aoyama, Kenichi Ikejima, Kazuyoshi Kon, Hisafumi Yamagata, Shunhei Yamashina, Satoko Suzuki, Sumio Watanabe Poor hepatic regeneration is profoundly involved in the pathogenesis of nonalcoholic steatohepatitis. Indeed, we demonstrated that liver regeneration after partial hepatectomy (PH) is markedly impaired in KK-Ay mice, which develop steatohepatitis based on insulin resistance. Paradoxically, these mice exhibit augmented induction of TNF-α after PH, while TNF-α is well-accepted as a trigger of normal regeneration. In this study, therefore, we investigated the early-phase regeneration process in KK-Ay mice after PH, especially focusing on the events related to TNF-α. Methods: Male, 9 week-old C57Bl/6 and KK-Ay mice underwent 70% PH. Proliferation and apoptosis of hepatocytes were detected by immunohistochemistry for PCNA and M30 CytoDEATH, respectively. Granulocyte infiltration was evaluated by esterase staining. Cyclin D1 and phospho-STAT3 were detected by Western blotting. NFκB DNA binding in the liver was detected by gel-shift assay. TNF-α and IL-6 mRNA were measured by real time RT-PCR. Results: The percentages of PCNA-positive hepatocytes reached only 3% in KK-Ay mice, indicating poor regeneration. In KK-Ay mice, hepatic TNFα mRNA was increased tremendously 1 hr after PH, the levels reaching 9-fold over those in Bl/6 mice. Indeed, NFκB activation was markedly enhanced with the initial peak at 0.5 hr after PH in KK-Ay mice. Moreover, NFκB activity was recurrently increased with the second peak at 12 hr after PH only in KK-Ay mice. Despite of enhanced TNF-α, apoptotic hepatocytes were barely detectable, and granulocyte infiltration was not obvious in KK-Ay mice given PH. On the other hand, induction of IL-6 mRNA was markedly enhanced with biphasic elevations at 3 and 12hr after PH in KK-Ay mice. STAT3 phosphorylation in the liver was also augmented with sustained pattern in KK-Ay mice. Furthermore, KK-Ay mice lacked increases in cyclin D1 levels after PH almost completely. Conclusions: These findings indicated that aberrant increases in TNF-α trigger hepatic regeneration failure after PH in KK-Ay mice, most likely through enhanced NFκB activity in Kupffer cells. Augmented TNFα response in KK-Ay mice does not elicit apoptosis of hepatocytes nor inflammatory responses, but rather leads to aberrant overproduction of IL-6 following PH, thereby causing dysregulation of the JAK/STAT signal and cyclin D1 expression. It is therefore postulated that alteration in innate immunity involving Kupffer cell activation plays a central role in impaired liver regeneration in metabolic syndrome-related steatohepatitis.
T1617 Therapeutic Effect of Increased Hepatic Lysosomal Acid Lipase in a Murine Model of Non-Alcoholic Fatty Liver Disease (NAFLD) Melanie Rhue, Hong Du, Gregory Grabowski INTRODUCTION: There are limited therapeutic options for NAFLD. Lysosomal acid lipase (LAL) is the critical enzyme for the hydrolysis of triglycerides and cholesteryl esters delivered to the lysosome. We hypothesized that increased hepatic LAL expression would improve the NAFLD lesion in our mouse model. METHODS: Ldl receptor knock-out mice (ldlr-/-) develop progressive hepatic steatosis and fibrosis when placed on a western diet. Using a doxycycline-inducible tet-off LAP-tTA mouse model system, the absence of doxycycline induces the expression of hepatic LAL; these mice were bred into a ldlr-/- background (LAPtTA/(tetO)7-hLAL;ldlr-/-). LAP-tTA/(tetO)7-hLAL;ldlr-/- (LAP) and ldlr-/- male mice were analyzed after 2, 4, and 5 months of western diet; male wild type and ldlr-/- mice also served as age-matched, standard diet controls. We collected body and liver weight data and performed hepatic LAL enzyme activity assays; hepatic sections were examined after H&E, Oil-Red-O, and Masson's trichrome staining. RESULTS: The hepatic LAL activity level of the LAP mouse group is 2-2.8 times higher than the other mouse groups (p<0.0001). After 4 months of western diet, the mean body weight of the ldlr-/- and LAP mice are higher than that of the standard diet mice (p<0.0001). Although there is no statistically significant difference between their body weights, the mean liver weight is lower in the western diet LAP compared to the western diet ldlr-/- at 4 and 5 months (p=0.002). After 4 months, the liver-to-body weight ratio is higher in the western diet ldlr-/- mice than the western diet LAP mice (p=0.002) and standard diet mice (p=0.029). The western diet LAP mice have less hepatic steatosis and less hepatic fibrosis than the western diet ldlr-/- mice at each time point. There is no significant difference between the standard diet ldlr-/- and wild type mice. CONCLUSION: Increased hepatic LAL expression delays the progression of hepatic steatosis and fibrosis in our model. LAL should be further explored as a potential enzyme therapy for NAFLD.
T1620 Loss of Mitochondrial Content and Function Contribute to the Natural History of Nonalcoholic Fatty Liver Disease in a Hyperphagic Obese Rodent Model Scott Rector, John P. Thyfault, Grace M. Uptergrove, E Matthew Morris, Scott P. Naples, Sarah J. Borengasser, Catherine R. Mikus, Matthew J. Laye, M Harold Laughlin, Frank W. Booth, Jamal A. Ibdah Background: Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease in westernized societies. Here, we sought to determine whether mitochondrial dysfunction plays a role in the natural history of NAFLD in the hyperphagic, obese, Otsuka Long-Evans Tokushima Fatty (OLETF) rat. Methods: Hyperphagic, obese OLETF and nonhyperphagic, control strain Long-Evans Tokushima Otsuka (LETO) rats were sacrificed at 13, 20, and 40 wks of age (n=6-8 per group) to examine hepatic mitochondrial content, function, and morphology and their association with NAFLD progression. Results: OLETF animals gained significantly more weight and body fat (p<0.001) compared with LETO animals at all ages. OLETF animals exhibited progressively elevated levels of hepatic triglycerides, hepatocyte ballooning, increased perivenular fibrosis and collagen deposition, and a doubling in serum ALT levels that occurred with aging compared with LETO rats. Electron microscopy images revealed that the OLETF rats developed ultrastructural abnormalities of the mitochondria, including apparent disruptions in the cristea and mitochondrial swelling/ rounding at 20 and 40 weeks of age; these findings were not apparent in the LETO animals. Mitochondrial alterations in OLETF rats also were associated with significant reductions in hepatic mitochondrial function, including a 20% reduction in hepatic carnitine palmitoylCoA transferase-1 activity and ~50% reduction in complete hepatic fatty acid oxidation at all ages studied. In addition, hepatic mitochondrial DNA encoded protein, cytochrome oxidase IV-subunit I expression was reduced by 30% at 40 weeks and total cytochrome c protein content in liver was 25-30% lower in the OLETF rats compared with LETO animals at 13, 20, and 40 weeks. This loss in mitochondrial content was further confirmed by significantly (p<0.01) reduced immunofluorescence staining for the mitochondrial specific marker carbamoyl phosphate synthetase-1 at 40 weeks of age in OLETF rats. Conclusions: Collectively, compelling evidence is provided that mitochondrial content, function, and mitochondrial health are disrupted with aging in a hyperphagic, obese animal model. Our study suggests that mitochondrial dysfunction and impaired mitochondrial fatty acid oxidation contribute to the natural history of obesity-associated NAFLD.
T1618 Eicosapentaenoic Acid Suppresses Steatohepatitis and Hepatocellular Carcinoma in a Mouse Model of Nonalcoholic Steatohepatitis Hajime Ishii, Yasuo Horie, Shigetoshi Ohshima, Yumiko Anezaki, Nobukatsu Kinoshita, Takashi Goto, Hirohide Ohnishi Background/Aims: Currently nonalcoholic steatohepatitis (NASH) is paid a serious attention as a public health problem worldwide and a mortal liver disease progressing to liver cirrhosis and hepatocellular carcinoma. However, there has been no definitive treatment regimen for this disease yet. Hepatocyte-specific Pten-deficient mice, that we established (JCI 113; 17741783, 2004), reproduce pathological and clinical findings consistent with human NASH. Accordingly, to test whether eicosapentaenoic acid (EPA), an agent for improving lipid metabolism, is an effective therapeutic regimen for NASH, we have administered it to Pten-deficient mice and investigated the effect of EPA to steatohepatitis and hepatocellular carcinoma of these mice. Methods : Pten-deficient mice were fed a standard chow (control group) or a 5% EPA contained-chow (EPA group) just after weaning. At 40 weeks, livers from each group were processed for measuring lipid content, gene expression analysis, Western blotting analysis, and histological examination. Level of serum reactive oxygen
AASLD Abstracts
A-850
species (ROS) was also determined. Forty- and 76-week-old mice were used in tumor burden experiments. Results: EPA improved hepatic steatosis in Pten-deficient mice based on decreased expression of AMPKα1-mediated SREBP-1c and increased PPARα expression. The EPA group exhibited less severe chronic hepatic inflammation compared to the control group, resulting from decreased ROS formation and a dramatically low ratio of arachidonic acid to EPA. Moreover, EPA inhibited development of hepatocellular carcinoma (HCC) in Pten-deficient mice based on an inhibition of MAPK activity and a low ratio of oleic to stealic acid, and a reduction in ROS formation. Conclusions: EPA suppressed steatohepatitis and development of HCC in Pten-deficient mice. We propose EPA as a potent therapeutic reagent of human NASH.
AASLD Abstracts
Pan-Caspase Inhibitor VX-166 Reduces Fibrosis in An Animal Model of NonAlcoholic Steatohepatitis Rafal P. Witek, Walter C. Stone, Gamze F. Karaca, John Pollard, Peter Charlton, Anna Mae Diehl Background: Nonalcoholic Fatty Liver Disease (NAFLD) is a potentially progressive liver disease that culminates in cirrhosis in some individuals. Cirrhosis occurs more often in individuals with nonalcoholic steatohepatitis (NASH) than in those with steatosis (NAFL). A major difference between NAFL and NASH is the extent of hepatocyte apoptosis, which is much more extensive in NASH. Phagocytosis of apoptotic cells is known to activate hepatic stellate cells (HSC) to a myofibroblastic phenotype. Thus, we examined the hypothesis that a pan-caspase inhibitor, VX-166, would reduce progression of fibrosis in a mouse model of NASH. Methods: 8-10-week old obese, male C57/BL6 db/db mice were fed Methionine Choline Deficient (MCD) diets (n=35) to induce NASH and liver fibrosis. Controls (n=35) were fed normal chow. In each group, 25 mice were gavaged once daily with the pancaspase inhibitor VX-166 (6mg/kg/d; Vertex; Abingdon, UK) in Poly-ethylene glycol (PEG), and remaining 10 mice received PEG only. In each group half of the mice were sacrificed at 4 weeks and half at 8 weeks. At sacrifice, liver tissue and serum were collected and assessed for liver injury (ALT, NAS score), caspase 3 activity, triglycerides, and fibrosis (collagen 1α1 and α-Smooth Muscle Actin (αSMA)) by biochemical assays, western blot (WB) and qRT-PCR. Results: Chow-fed db/db mice had NAFL. MCD caused NASH and fibrosis in db/db mice. WB revealed that MCD also increased caspase 3 activity. Treatment of MCD-fed db/db mice with VX-166 decreased active caspase 3 by 2-fold at 4 weeks (p<0.05) and 0.5 fold at 8 weeks (p<0.05). Results were confirmed by IHC. Liver histology showed that VX-166 treatment decreased steatosis; hepatic triglyceride content was also lower than controls (p<0.05). ALT levels were similar in control and VX-166-treated MCD-fed db/db mice. Histology confirmed that both groups had liver injury (NAS≥4). Nevertheless, treatment of MCD-fed db/db mice with VX-166 significantly reduced αSMA expression (WB, 2-fold reduction at 4 weeks, p<0.05; 3-fold reduction at 8 weeks, p<0.005), and collagen 1α1 mRNA levels (one-fold reduction at 8 weeks, p<0.05). Histology confirmed decreases in αSMA and fibrosis. Conclusion: Inhibiting hepatic apoptosis reduced accumulation of αSMA and suppressed development of fibrosis in obese mice with diet-induced NASH. Beneficial effects on liver fibrosis were associated with reductions in hepatic steatosis, but occurred without obvious improvement in liver injury. The observations are consistent with evidence that apoptosis triggers HSC activation and liver fibrosis, and suggest that caspase inhibitors may be useful as an anti-fibrotic therapy in NASH.
T1619 Alteration in Hepatic Innate Immunity Triggers Hepatic Regeneration Failure in Obese and Diabetic Kk-aY Mice Tomonori Aoyama, Kenichi Ikejima, Kazuyoshi Kon, Hisafumi Yamagata, Shunhei Yamashina, Satoko Suzuki, Sumio Watanabe Poor hepatic regeneration is profoundly involved in the pathogenesis of nonalcoholic steatohepatitis. Indeed, we demonstrated that liver regeneration after partial hepatectomy (PH) is markedly impaired in KK-Ay mice, which develop steatohepatitis based on insulin resistance. Paradoxically, these mice exhibit augmented induction of TNF-α after PH, while TNF-α is well-accepted as a trigger of normal regeneration. In this study, therefore, we investigated the early-phase regeneration process in KK-Ay mice after PH, especially focusing on the events related to TNF-α. Methods: Male, 9 week-old C57Bl/6 and KK-Ay mice underwent 70% PH. Proliferation and apoptosis of hepatocytes were detected by immunohistochemistry for PCNA and M30 CytoDEATH, respectively. Granulocyte infiltration was evaluated by esterase staining. Cyclin D1 and phospho-STAT3 were detected by Western blotting. NFκB DNA binding in the liver was detected by gel-shift assay. TNF-α and IL-6 mRNA were measured by real time RT-PCR. Results: The percentages of PCNA-positive hepatocytes reached only 3% in KK-Ay mice, indicating poor regeneration. In KK-Ay mice, hepatic TNFα mRNA was increased tremendously 1 hr after PH, the levels reaching 9-fold over those in Bl/6 mice. Indeed, NFκB activation was markedly enhanced with the initial peak at 0.5 hr after PH in KK-Ay mice. Moreover, NFκB activity was recurrently increased with the second peak at 12 hr after PH only in KK-Ay mice. Despite of enhanced TNF-α, apoptotic hepatocytes were barely detectable, and granulocyte infiltration was not obvious in KK-Ay mice given PH. On the other hand, induction of IL-6 mRNA was markedly enhanced with biphasic elevations at 3 and 12hr after PH in KK-Ay mice. STAT3 phosphorylation in the liver was also augmented with sustained pattern in KK-Ay mice. Furthermore, KK-Ay mice lacked increases in cyclin D1 levels after PH almost completely. Conclusions: These findings indicated that aberrant increases in TNF-α trigger hepatic regeneration failure after PH in KK-Ay mice, most likely through enhanced NFκB activity in Kupffer cells. Augmented TNFα response in KK-Ay mice does not elicit apoptosis of hepatocytes nor inflammatory responses, but rather leads to aberrant overproduction of IL-6 following PH, thereby causing dysregulation of the JAK/STAT signal and cyclin D1 expression. It is therefore postulated that alteration in innate immunity involving Kupffer cell activation plays a central role in impaired liver regeneration in metabolic syndrome-related steatohepatitis.
T1617 Therapeutic Effect of Increased Hepatic Lysosomal Acid Lipase in a Murine Model of Non-Alcoholic Fatty Liver Disease (NAFLD) Melanie Rhue, Hong Du, Gregory Grabowski INTRODUCTION: There are limited therapeutic options for NAFLD. Lysosomal acid lipase (LAL) is the critical enzyme for the hydrolysis of triglycerides and cholesteryl esters delivered to the lysosome. We hypothesized that increased hepatic LAL expression would improve the NAFLD lesion in our mouse model. METHODS: Ldl receptor knock-out mice (ldlr-/-) develop progressive hepatic steatosis and fibrosis when placed on a western diet. Using a doxycycline-inducible tet-off LAP-tTA mouse model system, the absence of doxycycline induces the expression of hepatic LAL; these mice were bred into a ldlr-/- background (LAPtTA/(tetO)7-hLAL;ldlr-/-). LAP-tTA/(tetO)7-hLAL;ldlr-/- (LAP) and ldlr-/- male mice were analyzed after 2, 4, and 5 months of western diet; male wild type and ldlr-/- mice also served as age-matched, standard diet controls. We collected body and liver weight data and performed hepatic LAL enzyme activity assays; hepatic sections were examined after H&E, Oil-Red-O, and Masson's trichrome staining. RESULTS: The hepatic LAL activity level of the LAP mouse group is 2-2.8 times higher than the other mouse groups (p<0.0001). After 4 months of western diet, the mean body weight of the ldlr-/- and LAP mice are higher than that of the standard diet mice (p<0.0001). Although there is no statistically significant difference between their body weights, the mean liver weight is lower in the western diet LAP compared to the western diet ldlr-/- at 4 and 5 months (p=0.002). After 4 months, the liver-to-body weight ratio is higher in the western diet ldlr-/- mice than the western diet LAP mice (p=0.002) and standard diet mice (p=0.029). The western diet LAP mice have less hepatic steatosis and less hepatic fibrosis than the western diet ldlr-/- mice at each time point. There is no significant difference between the standard diet ldlr-/- and wild type mice. CONCLUSION: Increased hepatic LAL expression delays the progression of hepatic steatosis and fibrosis in our model. LAL should be further explored as a potential enzyme therapy for NAFLD.
T1620 Loss of Mitochondrial Content and Function Contribute to the Natural History of Nonalcoholic Fatty Liver Disease in a Hyperphagic Obese Rodent Model Scott Rector, John P. Thyfault, Grace M. Uptergrove, E Matthew Morris, Scott P. Naples, Sarah J. Borengasser, Catherine R. Mikus, Matthew J. Laye, M Harold Laughlin, Frank W. Booth, Jamal A. Ibdah Background: Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease in westernized societies. Here, we sought to determine whether mitochondrial dysfunction plays a role in the natural history of NAFLD in the hyperphagic, obese, Otsuka Long-Evans Tokushima Fatty (OLETF) rat. Methods: Hyperphagic, obese OLETF and nonhyperphagic, control strain Long-Evans Tokushima Otsuka (LETO) rats were sacrificed at 13, 20, and 40 wks of age (n=6-8 per group) to examine hepatic mitochondrial content, function, and morphology and their association with NAFLD progression. Results: OLETF animals gained significantly more weight and body fat (p<0.001) compared with LETO animals at all ages. OLETF animals exhibited progressively elevated levels of hepatic triglycerides, hepatocyte ballooning, increased perivenular fibrosis and collagen deposition, and a doubling in serum ALT levels that occurred with aging compared with LETO rats. Electron microscopy images revealed that the OLETF rats developed ultrastructural abnormalities of the mitochondria, including apparent disruptions in the cristea and mitochondrial swelling/ rounding at 20 and 40 weeks of age; these findings were not apparent in the LETO animals. Mitochondrial alterations in OLETF rats also were associated with significant reductions in hepatic mitochondrial function, including a 20% reduction in hepatic carnitine palmitoylCoA transferase-1 activity and ~50% reduction in complete hepatic fatty acid oxidation at all ages studied. In addition, hepatic mitochondrial DNA encoded protein, cytochrome oxidase IV-subunit I expression was reduced by 30% at 40 weeks and total cytochrome c protein content in liver was 25-30% lower in the OLETF rats compared with LETO animals at 13, 20, and 40 weeks. This loss in mitochondrial content was further confirmed by significantly (p<0.01) reduced immunofluorescence staining for the mitochondrial specific marker carbamoyl phosphate synthetase-1 at 40 weeks of age in OLETF rats. Conclusions: Collectively, compelling evidence is provided that mitochondrial content, function, and mitochondrial health are disrupted with aging in a hyperphagic, obese animal model. Our study suggests that mitochondrial dysfunction and impaired mitochondrial fatty acid oxidation contribute to the natural history of obesity-associated NAFLD.
T1618 Eicosapentaenoic Acid Suppresses Steatohepatitis and Hepatocellular Carcinoma in a Mouse Model of Nonalcoholic Steatohepatitis Hajime Ishii, Yasuo Horie, Shigetoshi Ohshima, Yumiko Anezaki, Nobukatsu Kinoshita, Takashi Goto, Hirohide Ohnishi Background/Aims: Currently nonalcoholic steatohepatitis (NASH) is paid a serious attention as a public health problem worldwide and a mortal liver disease progressing to liver cirrhosis and hepatocellular carcinoma. However, there has been no definitive treatment regimen for this disease yet. Hepatocyte-specific Pten-deficient mice, that we established (JCI 113; 17741783, 2004), reproduce pathological and clinical findings consistent with human NASH. Accordingly, to test whether eicosapentaenoic acid (EPA), an agent for improving lipid metabolism, is an effective therapeutic regimen for NASH, we have administered it to Pten-deficient mice and investigated the effect of EPA to steatohepatitis and hepatocellular carcinoma of these mice. Methods : Pten-deficient mice were fed a standard chow (control group) or a 5% EPA contained-chow (EPA group) just after weaning. At 40 weeks, livers from each group were processed for measuring lipid content, gene expression analysis, Western blotting analysis, and histological examination. Level of serum reactive oxygen
AASLD Abstracts
A-850