- Email: [email protected]
T1021 Ultrasonographic Evaluation of Gallbladder Motility in Patients with Non-Alcoholic Fatty Liver Disease
PUFA group. Conclusions: An 8 week course of omega-3 PUFA did not result in a significant decrease in the degree of hepatic steatosis as determined by MRS. However subjects in the PUFA group also had an increased body fat mass which may have contributed to their lack of decreased steatosis. PUFA therapy was associated with an improvement in resting metabolic rate and insulin response. Further studies are needed to the mechanism for this.
littermates were randomly assigned to either a sedentary control (SED-SD and SED-Ren2) or a group treadmill trained for 6 weeks (EX-SD and EX-Ren2). RESULTS: SED-Ren2 rats developed higher systolic blood pressure (SBP) compared to SED-SD rats, exercise training did not reduce SBP compared with SED-Ren2 controls. Exercise also did not attenuate body weight gain in the12-week old Ren2 rats compared with sedentary Ren2. Compared with SED-SD, SED-Ren2 rats at 12weeks of age developed hepatic steatosis (assessed by H&E, Oil Red O staining and hepatic triglycerides (TG) levels), decreased mitochondrial content (assessed by mitochondrial marker CPS1), and decreased enzymatic activities of β-hydroxyacyl-CoA dehydrogenase (β-HAD) and citrate synthase (CS). Six weeks of exercise attenuated hepatic steatosis and improved mitochondrial content and enzymatic activities in Ren2 rats. Exercise substantially reduced the elevated NADPH oxidase activity and enhanced the superoxide dismutase (SOD) activity and improved lipid peroxidation (assessed by measuring 4-HNE levels) in Ren2 livers. CONCLUSIONS: These results demonstrate that exercise exerts beneficial effect in preventing Ang II-induced NAFLD via attenuation of hepatic oxidative stress. Our study further suggests that the protective effect of exercise on hepatic steatosis is through preserving hepatic mitochondrial content and improving mitochondrial function.
T1020
AASLD Abstracts
Dysfunctional VLDL Synthesis and Release Is a Key Factor in Non-Alcoholic Steatohepatitis(NASH) Progression Koji Fujita, Yuichi Nozaki, Masato Yoneda, Hiroki Endo, Hirokazu Takahashi, Masahiko Inamori, Hiroyuki Kirikoshi, Yasunobu Abe, Hiroshi Iida, Hironori Mawatari, Noritoshi Kobayashi, kensuke kubota, Satoru Saito, Atsushi Nakajima Background: The specific mechanisms of hepatic lipid accumulation in patients with NAFLD remain unknown. Although it is required for the prevention of progression from NAFL to NASH, there are no report about the comparison between NAFL and NASH. In the present study, we investigated the difference between NAFL and NASH about the liver lipid metabolites, especially fatty acid inflow, VLDL synthesis and secretion. Methods: One hundred and four Japanese subjects (50 men and 54 postmenopausal women; mean age, 50.2 + 13.1 years; mean BMI, 28.4 + 5.9 kg/m2) with histologically verified NAFLD (51 with NAFL, 53 with NASH) were evaluated; all diagnoses were based on liver biopsy findings and the diagnostic criteria proposed by Brunt. We minutely analyzed about (I) lipid flow and accumulation in the liver (CM inflow, fatty acid synthesis acid accumulation), (II) lipid flow out from the liver (VLDL secretion), and (III) lipid synthesis and release in the liver (TG transportation, lipoprotein synthesis, lipoprotein release) to investigate the difference between NAFL and NASH in patients. Findings: Most of the hepatic lipid metabolite profiles were similar in the NAFL and NASH groups. However, serum VLDL-TG secretion (P=0.035), hepatic apoB100 expression (P=0.026), phospholipid synthesis (as measured by [11C]choline uptake in the liver) (P=0.042), and especially hepatic MTTP activation (P<0.001) tended to deteriorate as NAFLD progressed (from NAFL to NASH). Moreover, analyzed by single nucleotide polymorphisms, NASH patients tend to have a much higher incidence of the MTTP gene G allele (P=0.062) and of the G/G genotype (P=0.055) compared to the NAFL. Interpretation: Dysfunctional VLDL synthesis and release, caused by the impediment of TG transportation via MTTP activation and a lower expression of liver ApoB100, may be a key factor in progression to NASH, and functional polymorphisms in MTTP may be involved in determining susceptibility of NASH.
*P<0.05 vs. SED-SD, **P<0.01 vs. SED-Ren2. #P<0.01 vs. SED-SD, ##P<0.01 vs. SEDRen2. ‡P<0.05 vs. SED-SD, ‡‡P<0.05 vs. SED-Ren2. N=numbers/group. T1610 Follow-Up Study of the Progression of Non-Alcoholic Steatohepatitis (NASH) in An Inducible Nitric Oxide Synthase (iNOS)-Knockout Mouse Model Yuichi Nozaki, Koji Fujita, Masato Yoneda, Koichiro Wada, Yoshiyasu Shinohara, Hironori Mawatari, Hirokazu Takahashi, Masahiko Inamori, Noritoshi Kobayashi, Hiroyuki Kirikoshi, kensuke kubota, Satoru Saito, Yoji Nagashima, Atsushi Nakajima Backgrounds and aims: Inducible nitric oxide synthase (iNOS) can be stimulated by inflammatory cytokines to produce large quantities of nitric oxide (NO). Examination of the serum levels of NO metabolites and iNOS-specific immunohistochemical analysis of the livers of several chronic liver disease patients have revealed increased iNOS expression in the NASH liver; therefore, it appears that iNOS is important in the progression of NASH. Methods: Our experimental study was conducted using male C57BL/6J mice (WT) and iNOS-knockout mice (KO). Each of these models was divided into two groups according to the diet, namely, a basal diet (BD) or a high-fat diet (HFD). The study period was 10 weeks and 48 weeks, respectively, in the simple steatosis (SS) model and non-alcoholic steatohepatitis (NASH) model. Results: WT and KO mice fed BD showed no fat deposits or liver inflammation. Examination of the livers of the mice fed HFD revealed fatty liver in the 10week-SS model and steatosis, hepatitis and liver fibrosis in the 48-week NASH model. In the SS model, the WT mice showed significantly more severe fatty liver (liver TG; p=0.032), and a tendency towards increased insulin resistance as compared with the KO mice. In the NASH model, the WT mice showed significantly more severe fatty liver (liver TG; p=0.021), but milder hepatitis (serum ALT; p=0.021) as compared to the KO mice. While the KO mice fed HFD showed F2 -F3 fibrosis according to the Brunt classification, the WT mice fed HFD showed little fibrosis (liver collagen one mRNA expression; p=0.014). In the NASH model, the WT mice showed a tendency towards increased insulin resistance and worsening of the lipid metabolic disorder in the liver (liver MTP mRNA expression; p=0.021, serum VLDL / CM ratio; p=0.014) as compared to the KO mice. On the other hand, the liver PDGF-β and TGF-β mRNA expression levels were significantly increased in the KO mice as compared with the levels in the WT mice (p=0.025 and p=0.014, respectively). Similarly, the liver TIMP-1 and TIMP-2 mRNA expression levels were significantly increased in the KO mice as compared with the levels in the WT mice (p=0.021 and p=0.016, respectively). Conclusion: Our study results suggested that iNOS-derived NO causes insulin resistance and lipid metabolic disorder in the liver, promoting the progression of the 1st hit in the pathogenesis of NASH. On the other hand, it decreases the production of several cytokines thereby protecting against the progression of the 2nd hit in the pathogenesis of NASH. Thus, we propose that iNOS plays two opposing roles in the pathogenesis of NASH.
T1021 Ultrasonographic Evaluation of Gallbladder Motility in Patients with NonAlcoholic Fatty Liver Disease Ofelia Mosteanu, Teodora Atena Pop, Claudia Buzas, Monica Acalovschi Background: Patients with non-alcoholic fatty liver (NAFLD) have an increased incidence of gallstones. The metabolic factors are important for gallstone pathogenesis in this condition, but impaired gallbladder emptying has also been suggested as a possible underlying mechanism. Our aim was to investigate gallbladder motility in patients with NAFLD. Methods: The study was performed in 93 patients with NAFLD: 58 of them had nonalcoholic steatohepatitis (20 men and 38 women, mean age 47.12 ± 8.57 years) (the NASH subgroup), and 35 patients had nonalcoholic steatosis (14 men and 21 women, mean age 52.43 ± 8.09 years) (the steatosis subgroup). NAFLD was confirmed histologically in 24 patients. In the patients in whom biopsy was contraindicated or refused, NAFLD was defined by the concomitant presence of three characteristics: (a) ultrasound evidence of bright liver; (b) absent to low daily alcohol intake (<30 g for men and <20 g for women); and (c) absence of known etiology of chronic liver disease, notably viral, autoimmune, drug induced, hemodynamic or genetic-metabolic.The control group included 43 patients (15 men and 28 women, mean age 50.6± 9.1 years) with no chronic liver disease or gallbladder disease. Fasting gallbladder volume (FV) was measured and gallbladder emptying [RV-minimal residual volume, FE= (FV-RV)/FV*100 and AUC (area under the curve)] was monitored by ultrasound, using the ellipsoid method, for 90 minutes, after a test meal (14 g fat, 425 kcal). Results: Both the patients with NASH and those with steatosis had an increased FV comparative with controls (p<0.05). Also, RV and EF were increased in patients with NASH and steatosis as compared with controls (p<0.05)]. Mean FV was significantly increased in diabetic NASH patients, as compared with NASH patients without diabetes (p=0.0048). Mean RV and EF were not significantly different between the two subgroups. We found no difference regarding gallbladder emptying (EF) between patients with NASH and steatosis. Conclusion: The present study, to our knowledge the first report in the literature, found a significantly decreased gallbladder motility in patients with NAFLD. This could be a contributive factor to cholesterol gallstone formation in NAFLD.
T1611 T1609
Activation of Hepatic Fibrogenesis in SREBP-1A Transgenic Mice: A Mouse Model of Fatty Liver Michele J. Alkalay, Sahng Wook Park, Lauren N. Koob, Nate Weymouth, Don C. Rockey, Jay D. Horton
Exercise Attenuates Hepatic Oxidative Stress and Prevents Fatty Liver Disease in Hypertensive Transgenic Ren2 Rats Yongzhong Wei, Grace Uptergrove, Scott P. Naples, Suzanne Ridenhour, Craig Stump, John P. Thyfault, Adam Whaley-Connell, Carlos M. Ferrario, James R. Sowers, Jamal A. Ibdah
BACKGROUND: Hepatic steatosis is present in ~33% of the population and ~10-20% of those develop steatohepatitis and fibrosis. Sterol regulatory element binding protein-1a (SREBP-1a) transcriptionally activates genes encoding fatty acid biosynthetic enzymes, which increases de novo fatty acid and triglyceride (TG) synthesis, leading to hepatic steatosis. We hypothesized that transgenic mice overexpressing nuclear SREBP-1a in hepatocytes (TgBP1a) would develop stellate cell activation and fibrosis as a result of increased rates of de novo fatty acid synthesis. AIMS: Determine whether TG accumulation resulting from elevated rates of hepatic fatty acid synthesis leads to stellate cell activation and fibrosis. METHODS: Transgenic mice overexpressing amino acids 1-460 of human SREBP-1a under the control of the phosphoenolpyruvate carboxykinase promoter were backcrossed onto the BALB/ c genetic background for >8 generations. Aminotransferase (AMT) concentrations were determined in 3 to 4 month-old wild-type and TgBP-1a mice, and hepatic mRNA levels of
BACKGROUND and AIM: Evidence suggests a strong relationship between hypertension and nonalcoholic fatty liver disease (NAFLD). Angiotensin (Ang) II is known to play an integral role in the pathogenesis of hypertension and has also been implicated liver lipid metabolism. We have recently demonstrated that increased endogenous Ang II causes progressive hepatic steatosis, inflammation and fibrosis mediated by oxidative stress in a transgenic hypertensive Ren2 rat model with elevated tissue Ang II levels (J Hepatol 2008,49:417). Further, evidence indicates that exercise promotes an antioxidant effect. We therefore hypothesized that exercise might prevent Ang II-induced NAFLD in Ren2 rats via attenuation of hepatic oxidative stress. METHODS: Six-week old male Ren2 rats and Sprague-Dawley (SD)
AASLD Abstracts
A-848
littermates were randomly assigned to either a sedentary control (SED-SD and SED-Ren2) or a group treadmill trained for 6 weeks (EX-SD and EX-Ren2). RESULTS: SED-Ren2 rats developed higher systolic blood pressure (SBP) compared to SED-SD rats, exercise training did not reduce SBP compared with SED-Ren2 controls. Exercise also did not attenuate body weight gain in the12-week old Ren2 rats compared with sedentary Ren2. Compared with SED-SD, SED-Ren2 rats at 12weeks of age developed hepatic steatosis (assessed by H&E, Oil Red O staining and hepatic triglycerides (TG) levels), decreased mitochondrial content (assessed by mitochondrial marker CPS1), and decreased enzymatic activities of β-hydroxyacyl-CoA dehydrogenase (β-HAD) and citrate synthase (CS). Six weeks of exercise attenuated hepatic steatosis and improved mitochondrial content and enzymatic activities in Ren2 rats. Exercise substantially reduced the elevated NADPH oxidase activity and enhanced the superoxide dismutase (SOD) activity and improved lipid peroxidation (assessed by measuring 4-HNE levels) in Ren2 livers. CONCLUSIONS: These results demonstrate that exercise exerts beneficial effect in preventing Ang II-induced NAFLD via attenuation of hepatic oxidative stress. Our study further suggests that the protective effect of exercise on hepatic steatosis is through preserving hepatic mitochondrial content and improving mitochondrial function.
T1020
AASLD Abstracts
Dysfunctional VLDL Synthesis and Release Is a Key Factor in Non-Alcoholic Steatohepatitis(NASH) Progression Koji Fujita, Yuichi Nozaki, Masato Yoneda, Hiroki Endo, Hirokazu Takahashi, Masahiko Inamori, Hiroyuki Kirikoshi, Yasunobu Abe, Hiroshi Iida, Hironori Mawatari, Noritoshi Kobayashi, kensuke kubota, Satoru Saito, Atsushi Nakajima Background: The specific mechanisms of hepatic lipid accumulation in patients with NAFLD remain unknown. Although it is required for the prevention of progression from NAFL to NASH, there are no report about the comparison between NAFL and NASH. In the present study, we investigated the difference between NAFL and NASH about the liver lipid metabolites, especially fatty acid inflow, VLDL synthesis and secretion. Methods: One hundred and four Japanese subjects (50 men and 54 postmenopausal women; mean age, 50.2 + 13.1 years; mean BMI, 28.4 + 5.9 kg/m2) with histologically verified NAFLD (51 with NAFL, 53 with NASH) were evaluated; all diagnoses were based on liver biopsy findings and the diagnostic criteria proposed by Brunt. We minutely analyzed about (I) lipid flow and accumulation in the liver (CM inflow, fatty acid synthesis acid accumulation), (II) lipid flow out from the liver (VLDL secretion), and (III) lipid synthesis and release in the liver (TG transportation, lipoprotein synthesis, lipoprotein release) to investigate the difference between NAFL and NASH in patients. Findings: Most of the hepatic lipid metabolite profiles were similar in the NAFL and NASH groups. However, serum VLDL-TG secretion (P=0.035), hepatic apoB100 expression (P=0.026), phospholipid synthesis (as measured by [11C]choline uptake in the liver) (P=0.042), and especially hepatic MTTP activation (P<0.001) tended to deteriorate as NAFLD progressed (from NAFL to NASH). Moreover, analyzed by single nucleotide polymorphisms, NASH patients tend to have a much higher incidence of the MTTP gene G allele (P=0.062) and of the G/G genotype (P=0.055) compared to the NAFL. Interpretation: Dysfunctional VLDL synthesis and release, caused by the impediment of TG transportation via MTTP activation and a lower expression of liver ApoB100, may be a key factor in progression to NASH, and functional polymorphisms in MTTP may be involved in determining susceptibility of NASH.
*P<0.05 vs. SED-SD, **P<0.01 vs. SED-Ren2. #P<0.01 vs. SED-SD, ##P<0.01 vs. SEDRen2. ‡P<0.05 vs. SED-SD, ‡‡P<0.05 vs. SED-Ren2. N=numbers/group. T1610 Follow-Up Study of the Progression of Non-Alcoholic Steatohepatitis (NASH) in An Inducible Nitric Oxide Synthase (iNOS)-Knockout Mouse Model Yuichi Nozaki, Koji Fujita, Masato Yoneda, Koichiro Wada, Yoshiyasu Shinohara, Hironori Mawatari, Hirokazu Takahashi, Masahiko Inamori, Noritoshi Kobayashi, Hiroyuki Kirikoshi, kensuke kubota, Satoru Saito, Yoji Nagashima, Atsushi Nakajima Backgrounds and aims: Inducible nitric oxide synthase (iNOS) can be stimulated by inflammatory cytokines to produce large quantities of nitric oxide (NO). Examination of the serum levels of NO metabolites and iNOS-specific immunohistochemical analysis of the livers of several chronic liver disease patients have revealed increased iNOS expression in the NASH liver; therefore, it appears that iNOS is important in the progression of NASH. Methods: Our experimental study was conducted using male C57BL/6J mice (WT) and iNOS-knockout mice (KO). Each of these models was divided into two groups according to the diet, namely, a basal diet (BD) or a high-fat diet (HFD). The study period was 10 weeks and 48 weeks, respectively, in the simple steatosis (SS) model and non-alcoholic steatohepatitis (NASH) model. Results: WT and KO mice fed BD showed no fat deposits or liver inflammation. Examination of the livers of the mice fed HFD revealed fatty liver in the 10week-SS model and steatosis, hepatitis and liver fibrosis in the 48-week NASH model. In the SS model, the WT mice showed significantly more severe fatty liver (liver TG; p=0.032), and a tendency towards increased insulin resistance as compared with the KO mice. In the NASH model, the WT mice showed significantly more severe fatty liver (liver TG; p=0.021), but milder hepatitis (serum ALT; p=0.021) as compared to the KO mice. While the KO mice fed HFD showed F2 -F3 fibrosis according to the Brunt classification, the WT mice fed HFD showed little fibrosis (liver collagen one mRNA expression; p=0.014). In the NASH model, the WT mice showed a tendency towards increased insulin resistance and worsening of the lipid metabolic disorder in the liver (liver MTP mRNA expression; p=0.021, serum VLDL / CM ratio; p=0.014) as compared to the KO mice. On the other hand, the liver PDGF-β and TGF-β mRNA expression levels were significantly increased in the KO mice as compared with the levels in the WT mice (p=0.025 and p=0.014, respectively). Similarly, the liver TIMP-1 and TIMP-2 mRNA expression levels were significantly increased in the KO mice as compared with the levels in the WT mice (p=0.021 and p=0.016, respectively). Conclusion: Our study results suggested that iNOS-derived NO causes insulin resistance and lipid metabolic disorder in the liver, promoting the progression of the 1st hit in the pathogenesis of NASH. On the other hand, it decreases the production of several cytokines thereby protecting against the progression of the 2nd hit in the pathogenesis of NASH. Thus, we propose that iNOS plays two opposing roles in the pathogenesis of NASH.
T1021 Ultrasonographic Evaluation of Gallbladder Motility in Patients with NonAlcoholic Fatty Liver Disease Ofelia Mosteanu, Teodora Atena Pop, Claudia Buzas, Monica Acalovschi Background: Patients with non-alcoholic fatty liver (NAFLD) have an increased incidence of gallstones. The metabolic factors are important for gallstone pathogenesis in this condition, but impaired gallbladder emptying has also been suggested as a possible underlying mechanism. Our aim was to investigate gallbladder motility in patients with NAFLD. Methods: The study was performed in 93 patients with NAFLD: 58 of them had nonalcoholic steatohepatitis (20 men and 38 women, mean age 47.12 ± 8.57 years) (the NASH subgroup), and 35 patients had nonalcoholic steatosis (14 men and 21 women, mean age 52.43 ± 8.09 years) (the steatosis subgroup). NAFLD was confirmed histologically in 24 patients. In the patients in whom biopsy was contraindicated or refused, NAFLD was defined by the concomitant presence of three characteristics: (a) ultrasound evidence of bright liver; (b) absent to low daily alcohol intake (<30 g for men and <20 g for women); and (c) absence of known etiology of chronic liver disease, notably viral, autoimmune, drug induced, hemodynamic or genetic-metabolic.The control group included 43 patients (15 men and 28 women, mean age 50.6± 9.1 years) with no chronic liver disease or gallbladder disease. Fasting gallbladder volume (FV) was measured and gallbladder emptying [RV-minimal residual volume, FE= (FV-RV)/FV*100 and AUC (area under the curve)] was monitored by ultrasound, using the ellipsoid method, for 90 minutes, after a test meal (14 g fat, 425 kcal). Results: Both the patients with NASH and those with steatosis had an increased FV comparative with controls (p<0.05). Also, RV and EF were increased in patients with NASH and steatosis as compared with controls (p<0.05)]. Mean FV was significantly increased in diabetic NASH patients, as compared with NASH patients without diabetes (p=0.0048). Mean RV and EF were not significantly different between the two subgroups. We found no difference regarding gallbladder emptying (EF) between patients with NASH and steatosis. Conclusion: The present study, to our knowledge the first report in the literature, found a significantly decreased gallbladder motility in patients with NAFLD. This could be a contributive factor to cholesterol gallstone formation in NAFLD.
T1611 T1609
Activation of Hepatic Fibrogenesis in SREBP-1A Transgenic Mice: A Mouse Model of Fatty Liver Michele J. Alkalay, Sahng Wook Park, Lauren N. Koob, Nate Weymouth, Don C. Rockey, Jay D. Horton
Exercise Attenuates Hepatic Oxidative Stress and Prevents Fatty Liver Disease in Hypertensive Transgenic Ren2 Rats Yongzhong Wei, Grace Uptergrove, Scott P. Naples, Suzanne Ridenhour, Craig Stump, John P. Thyfault, Adam Whaley-Connell, Carlos M. Ferrario, James R. Sowers, Jamal A. Ibdah
BACKGROUND: Hepatic steatosis is present in ~33% of the population and ~10-20% of those develop steatohepatitis and fibrosis. Sterol regulatory element binding protein-1a (SREBP-1a) transcriptionally activates genes encoding fatty acid biosynthetic enzymes, which increases de novo fatty acid and triglyceride (TG) synthesis, leading to hepatic steatosis. We hypothesized that transgenic mice overexpressing nuclear SREBP-1a in hepatocytes (TgBP1a) would develop stellate cell activation and fibrosis as a result of increased rates of de novo fatty acid synthesis. AIMS: Determine whether TG accumulation resulting from elevated rates of hepatic fatty acid synthesis leads to stellate cell activation and fibrosis. METHODS: Transgenic mice overexpressing amino acids 1-460 of human SREBP-1a under the control of the phosphoenolpyruvate carboxykinase promoter were backcrossed onto the BALB/ c genetic background for >8 generations. Aminotransferase (AMT) concentrations were determined in 3 to 4 month-old wild-type and TgBP-1a mice, and hepatic mRNA levels of
BACKGROUND and AIM: Evidence suggests a strong relationship between hypertension and nonalcoholic fatty liver disease (NAFLD). Angiotensin (Ang) II is known to play an integral role in the pathogenesis of hypertension and has also been implicated liver lipid metabolism. We have recently demonstrated that increased endogenous Ang II causes progressive hepatic steatosis, inflammation and fibrosis mediated by oxidative stress in a transgenic hypertensive Ren2 rat model with elevated tissue Ang II levels (J Hepatol 2008,49:417). Further, evidence indicates that exercise promotes an antioxidant effect. We therefore hypothesized that exercise might prevent Ang II-induced NAFLD in Ren2 rats via attenuation of hepatic oxidative stress. METHODS: Six-week old male Ren2 rats and Sprague-Dawley (SD)
AASLD Abstracts
A-848