scholarly journals Time Course of the Development of Nonalcoholic Fatty Liver Disease in the Otsuka Long-Evans Tokushima Fatty Rat

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yi-Sun Song ◽  
Cheng-Hu Fang ◽  
Byung-Im So ◽  
Jun-Young Park ◽  
Yonggu Lee ◽  
...  
Keyword(s):  
Gene Expression ◽  
Liver Disease ◽  
Animal Models ◽  
Fatty Liver ◽  
Fatty Liver Disease ◽  
De Novo ◽  
Histological Changes ◽  
Nonalcoholic Fatty Liver ◽  
Oletf Rats ◽  
Long Evans

Nonalcoholic fatty liver disease (NAFLD) is considered a hepatic manifestation of metabolic syndrome. In this study, we investigated histological and biochemical changes in NAFLD and the gene expression involvingde novolipogenesis in Otsuka Long-Evans Tokushima fatty (OLETF) rats. We used OLETF rats and Long-Evans Tokushima Otsuka (LETO) rats as animal models of NAFLD and as controls, respectively. Consistent observations were made at 4-week intervals up to 50 weeks of age, and all rats were fed ad libitum with standard food. Biochemical and histological changes were observed, and gene expression involved inde novolipogenesis was measured using real-time polymerase chain reactions. As a results hepatic micro- and macrovesicular steatosis and hepatocyte ballooning were evident in the OLETF rats at 22–38 weeks of age but disappeared after 42 weeks; no fibrosis or collagen deposition was observed. Gene expression involved inde novolipogenesis followed a pattern similar to that of the histological changes. In conclusion, in the absence of dietary manipulation, hepatic steatosis in OLETF rats is evident at 22–38 weeks and declines after 42 weeks. Therefore, OLETF rats at 22–38 weeks are recommended as animal models of hepatic steatosis.

scholarly journals Daily exercise vs. caloric restriction for prevention of nonalcoholic fatty liver disease in the OLETF rat model

2011 ◽  
Vol 300 (5) ◽  
pp. G874-G883 ◽  
Author(s):  
R. Scott Rector ◽  
Grace M. Uptergrove ◽  
E. Matthew Morris ◽  
Sarah J. Borengasser ◽  
M. Harold Laughlin ◽  
...  
Keyword(s):  
Liver Disease ◽  
Glucose Tolerance ◽  
Fatty Liver ◽  
Caloric Restriction ◽  
Fatty Liver Disease ◽  
Nonalcoholic Fatty Liver ◽  
Oletf Rats ◽  
Daily Exercise ◽  
Long Evans ◽  
Oletf Rat

The maintenance of normal body weight either through dietary modification or being habitually more physically active is associated with reduced incidence of nonalcoholic fatty liver disease (NAFLD). However, the means by which weight gain is prevented and potential mechanisms activated remain largely unstudied. Here, we sought to determine the effects of obesity prevention by daily exercise vs. caloric restriction on NAFLD in the hyperphagic, Otsuka Long-Evans Tokushima Fatty (OLETF) rat. At 4 wk of age, male OLETF rats ( n = 7–8/group) were randomized to groups of ad libitum fed, sedentary (OLETF-SED), voluntary wheel running exercise (OLETF-EX), or caloric restriction (OLETF-CR; 70% of SED) until 40 wk of age. Nonhyperphagic, control strain Long-Evans Tokushima Otsuka (LETO) rats were kept in sedentary cage conditions for the duration of the study (LETO-SED). Both daily exercise and caloric restriction prevented obesity and the development of type 2 diabetes observed in the OLETF-SED rats, with glucose tolerance during a glucose tolerance test improved to a greater extent in the OLETF-EX animals (30–50% lower glucose and insulin areas under the curve, P < 0.05). Both daily exercise and caloric restriction also prevented excess hepatic triglyceride and diacylglycerol accumulation ( P < 0.001), hepatocyte ballooning and nuclear displacement, and the increased perivenular fibrosis and collagen deposition that occurred in the obese OLETF-SED animals. However, despite similar hepatic phenotypes, OLETF-EX rats also exhibited increased hepatic mitochondrial fatty acid oxidation, enhanced oxidative enzyme function and protein content, and further suppression of hepatic de novo lipogenesis proteins compared with OLETF-CR. Prevention of obesity by either daily exercise or caloric restriction attenuates NAFLD development in OLETF rats. However, daily exercise may offer additional health benefits on glucose homeostasis and hepatic mitochondrial function compared with restricted diet alone.

scholarly journals Altered Hepatic Lipid Metabolism Contributes to Nonalcoholic Fatty Liver Disease in Leptin-Deficient Ob/Ob Mice

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
James W. Perfield ◽  
Laura C. Ortinau ◽  
R. Taylor Pickering ◽  
Meghan L. Ruebel ◽  
Grace M. Meers ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lipid Metabolism ◽  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Liver Disease ◽  
De Novo ◽  
Hepatic Lipid Metabolism ◽  
Nonalcoholic Fatty Liver ◽  
Hepatic Lipid

Nonalcoholic fatty liver disease (NAFLD) is strongly linked to obesity, insulin resistance, and abnormal hepatic lipid metabolism; however, the precise regulation of these processes remains poorly understood. Here we examined genes and proteins involved in hepatic oxidation and lipogenesis in 14-week-old leptin-deficient Ob/Ob mice, a commonly studied model of obesity and hepatic steatosis. Obese Ob/Ob mice had increased fasting glucose, insulin, and calculated HOMA-IR as compared with lean wild-type (WT) mice. Ob/Ob mice also had greater liver weights, hepatic triglyceride (TG) content, and markers ofde novolipogenesis, including increased hepatic gene expression and protein content of acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS), and stearoyl-CoA desaturase-1 (SCD-1), as well as elevated gene expression of PPARγand SREBP-1c compared with WT mice. While hepatic mRNA levels for PGC-1α, PPARα, and TFAM were elevated in Ob/Ob mice, measures of mitochondrial function (β-HAD activity and complete (to CO2) and total mitochondrial palmitate oxidation) and mitochondrial OXPHOS protein subunits I, III, and V content were significantly reduced compared with WT animals. In summary, reduced hepatic mitochondrial content and function and an upregulation inde novolipogenesis contribute to obesity-associated NAFLD in the leptin-deficient Ob/Ob mouse.

scholarly journals Concepts and Treatment Approaches in Nonalcoholic Fatty Liver Disease

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Dina L. Halegoua-De Marzio ◽  
Jonathan M. Fenkel
Keyword(s):  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Liver Disease ◽  
De Novo ◽  
Imaging Techniques ◽  
De Novo Lipogenesis ◽  
Central Adiposity ◽  
Preventative Care ◽  
Nonalcoholic Fatty Liver

Nonalcoholic fatty liver disease (NAFLD) affects up to 30% of adults and is the most common liver disease in Western nations. NAFLD is associated with central adiposity, insulin resistance, type 2 diabetes mellitus, hyperlipidemia, and cardiovascular disease. It encompasses the entire spectrum of fatty liver diseases from simple steatosis to nonalcoholic steatohepatitis (NASH) with lobular/portal inflammation, hepatocellular necrosis, and fibrosis. Of those who develop NASH, 15–25% will progress to end stage liver disease and hepatocellular carcinoma over 10–20 years. Its pathogenesis is complex, and involves a state of lipid accumulation due to increased uptake of free fatty acids into the liver, impaired fatty acid beta oxidation, and increased incidence of de novo lipogenesis. Plasma aminotransferases and liver ultrasound are helpful in the diagnosis of NAFLD/NASH, but a liver biopsy is often required for definitive diagnosis. Many new plasma biomarkers and imaging techniques are now available that should improve the ability to diagnose NAFLD noninvasively Due to its complexity and extrahepatic complications, treatment of NAFLD requires a multidisciplinary approach with excellent preventative care, management, and treatment. This review will evaluate our current understanding of NAFLD, with a focus on existing therapeutic approaches and potential pharmacological developments.

scholarly journals Sex Dimorphism of Nonalcoholic Fatty Liver Disease (NAFLD) in Pparg-Null Mice

2021 ◽  
Vol 22 (18) ◽  
pp. 9969
Author(s):  
Mariano Schiffrin ◽  
Carine Winkler ◽  
Laure Quignodon ◽  
Aurélien Naldi ◽  
Martin Trötzmüller ◽  
...  
Keyword(s):  
Gene Expression ◽  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Liver Disease ◽  
Molecular Mechanisms ◽  
Liver Steatosis ◽  
Whole Body ◽  
Sex Dimorphism ◽  
Nonalcoholic Fatty Liver

Men with nonalcoholic fatty liver disease (NAFLD) are more exposed to nonalcoholic steatohepatitis (NASH) and liver fibrosis than women. However, the underlying molecular mechanisms of NALFD sex dimorphism are unclear. We combined gene expression, histological and lipidomic analyses to systematically compare male and female liver steatosis. We characterized hepatosteatosis in three independent mouse models of NAFLD, ob/ob and lipodystrophic fat-specific (PpargFΔ/Δ) and whole-body PPARγ-null (PpargΔ/Δ) mice. We identified a clear sex dimorphism occurring only in PpargΔ/Δ mice, with females showing macro- and microvesicular hepatosteatosis throughout their entire life, while males had fewer lipid droplets starting from 20 weeks. This sex dimorphism in hepatosteatosis was lost in gonadectomized PpargΔ/Δ mice. Lipidomics revealed hepatic accumulation of short and highly saturated TGs in females, while TGs were enriched in long and unsaturated hydrocarbon chains in males. Strikingly, sex-biased genes were particularly perturbed in both sexes, affecting lipid metabolism, drug metabolism, inflammatory and cellular stress response pathways. Most importantly, we found that the expression of key sex-biased genes was severely affected in all the NAFLD models we tested. Thus, hepatosteatosis strongly affects hepatic sex-biased gene expression. With NAFLD increasing in prevalence, this emphasizes the urgent need to specifically address the consequences of this deregulation in humans.

Predictors of De Novo Nonalcoholic Fatty Liver Disease After Liver Transplantation and Associated Fibrosis

2019 ◽  
Vol 25 (1) ◽  
pp. 56-67 ◽  
Author(s):  
Zita Galvin ◽  
Ramraj Rajakumar ◽  
Emily Chen ◽  
Oyedele Adeyi ◽  
Markus Selzner ◽  
...  
Keyword(s):  
Liver Transplantation ◽  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Liver Disease ◽  
De Novo ◽  
Nonalcoholic Fatty Liver

scholarly journals Gene Expression and DNA Methylation Alterations in the Glycine N-Methyltransferase Gene in Diet-Induced Nonalcoholic Fatty Liver Disease-Associated Carcinogenesis

2019 ◽  
Vol 170 (2) ◽  
pp. 273-282 ◽  
Author(s):  
Barbara Borowa-Mazgaj ◽  
Aline de Conti ◽  
Volodymyr Tryndyak ◽  
Colleen R Steward ◽  
Leandro Jimenez ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Animal Model ◽  
Liver Disease ◽  
Fatty Liver ◽  
Nonalcoholic Fatty Liver Disease ◽  
Fatty Liver Disease ◽  
The United States ◽  
Down Regulation ◽  
Nonalcoholic Fatty Liver

Abstract Nonalcoholic fatty liver disease (NAFLD) is becoming a major etiological risk factor for hepatocellular carcinoma (HCC) in the United States and other Western countries. In this study, we investigated the role of gene-specific promoter cytosine DNA methylation and gene expression alterations in the development of NAFLD-associated HCC in mice using (1) a diet-induced animal model of NAFLD, (2) a Stelic Animal Model of nonalcoholic steatohepatitis-derived HCC, and (3) a choline- and folate-deficient (CFD) diet (CFD model). We found that the development of NAFLD and its progression to HCC was characterized by down-regulation of glycine N-methyltransferase (Gnmt) and this was mediated by progressive Gnmt promoter cytosine DNA hypermethylation. Using a panel of genetically diverse inbred mice, we observed that Gnmt down-regulation was an early event in the pathogenesis of NAFLD and correlated with the extent of the NAFLD-like liver injury. Reduced GNMT expression was also found in human HCC tissue and liver cancer cell lines. In in vitro experiments, we demonstrated that one of the consequences of GNMT inhibition was an increase in genome methylation facilitated by an elevated level of S-adenosyl-L-methionine. Overall, our findings suggest that reduced Gnmt expression caused by promoter hypermethylation is one of the key molecular events in the development of NAFLD-derived HCC and that assessing Gnmt methylation level may be useful for disease stratification.

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