Evaluation of Methionine Content in a High-Fat and Choline-Deficient Diet on Body Weight Gain and the Development of Non-Alcoholic Steatohepatitis in Mice.

Tsuyoshi Chiba,Sachina Suzuki,Tatsuki Itoh,Yoko Sato,Keizo Umegaki,Giovanni Li Volti

doi:10.1371/journal.pone.0164191

Abstract

AimNon-alcoholic steatohepatitis (NASH) is a globally recognized liver disease. A methionine- and choline-deficient diet is used to induce NASH in mice; however, this diet also causes severe body weight loss. To resolve this issue, we examined the effects of methionine content in a high-fat and choline-deficient (HFCD) diet on body weight and the development of NASH in mice.MethodsC57BL/6J mice (male, 10 weeks of age) were fed an L-amino acid rodent (control) diet, high-fat (HF) diet, or HFCD diet containing various amounts of methionine (0.1–0.6% (w/w)) for 12 weeks. Plasma lipid levels, hepatic lipid content and inflammatory marker gene expression were measured, and a pathological analysis was conducted to evaluate NASH.ResultsThe 0.1% methionine in HFCD diet suppressed body weight gain, which was lower than that with control diet. On the other hand, the 0.2% methionine in HFCD diet yielded similar body weight gains as the control diet, while more than 0.4% methionine showed the same body weight gains as the HF diet. Liver weights and hepatic lipid contents were the greatest with 0.1% methionine and decreased in a methionine dose-dependent manner. Pathological analysis, NAFLD activity scores and gene expression levels in the liver revealed that 0.1% and 0.2% methionine for 12 weeks induced NASH, whereas 0.4% and 0.6% methionine attenuated the induction of NASH by HFCD diet. However, the 0.2% methionine in HFCD diet did not induce insulin resistance, despite the body weight gain.ConclusionsThe 0.2% methionine in HFCD diet for 12 weeks was able to induce NASH without weight loss.

Highlights

Non-alcoholic fatty liver disease (NAFLD) and the more progressive non-alcoholic steatohepatitis (NASH) have recently become recognized liver diseases in developed countries [1]
The 0.2% methionine in high-fat and choline-deficient (HFCD) diet yielded similar body weight gains as the control diet, while more than 0.4% methionine showed the same body weight gains as the HF diet
Pathological analysis, NAFLD activity scores and gene expression levels in the liver revealed that 0.1% and 0.2% methionine for 12 weeks induced NASH, whereas 0.4% and 0.6% methionine attenuated the induction of NASH by HFCD diet

Summary

Introduction

Non-alcoholic fatty liver disease (NAFLD) and the more progressive non-alcoholic steatohepatitis (NASH) have recently become recognized liver diseases in developed countries [1]. The prevalence of NAFLD has increased in Western countries, and in Asia [2] and Japan [3, 4]. 10–15% of NAFLD patients have been diagnosed with NASH [5], which may progress from steatosis and fibrosis to cirrhosis and hepatocellular carcinoma [6, 7]. NASH is characterized by the liver biopsy findings observed in alcoholic hepatitis, in addition to elevated plasma indicators of hepatic damage and lipid accumulation in the liver with NAFLD. NASH is associated with obesity and metabolic syndrome, such as insulin resistance, diabetes mellitus and dyslipidemia [8, 9]. Even though several animal models of NASH have been reported [10, 11], an optimal animal model of human NASH does not exist

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