Mouse models of diet-induced nonalcoholic steatohepatitis reproduce the heterogeneity of the human disease - PubMed (original) (raw)

Mouse models of diet-induced nonalcoholic steatohepatitis reproduce the heterogeneity of the human disease

Mariana Verdelho Machado et al. PLoS One. 2015.

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Abstract

Background and aims: Non-alcoholic steatohepatitis (NASH), the potentially progressive form of nonalcoholic fatty liver disease (NAFLD), is the pandemic liver disease of our time. Although there are several animal models of NASH, consensus regarding the optimal model is lacking. We aimed to compare features of NASH in the two most widely-used mouse models: methionine-choline deficient (MCD) diet and Western diet.

Methods: Mice were fed standard chow, MCD diet for 8 weeks, or Western diet (45% energy from fat, predominantly saturated fat, with 0.2% cholesterol, plus drinking water supplemented with fructose and glucose) for 16 weeks. Liver pathology and metabolic profile were compared.

Results: The metabolic profile associated with human NASH was better mimicked by Western diet. Although hepatic steatosis (i.e., triglyceride accumulation) was also more severe, liver non-esterified fatty acid content was lower than in the MCD diet group. NASH was also less severe and less reproducible in the Western diet model, as evidenced by less liver cell death/apoptosis, inflammation, ductular reaction, and fibrosis. Various mechanisms implicated in human NASH pathogenesis/progression were also less robust in the Western diet model, including oxidative stress, ER stress, autophagy deregulation, and hedgehog pathway activation.

Conclusion: Feeding mice a Western diet models metabolic perturbations that are common in humans with mild NASH, whereas administration of a MCD diet better models the pathobiological mechanisms that cause human NAFLD to progress to advanced NASH.

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Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Fig 1

Fig 1. Effects of MCD diet and Western diet on metabolic profile.

WT mice were fed chow diet, MCD diet for 8 weeks, or Western diet for 16 weeks, and sacrificed at 20 weeks of age. (A). Body weights; (B). Adipokines (leptin and adiponectin); (C). Fasting serum glucose and HOMA-IR index; (D). Serum triglycerides and non-esterified fatty acids (NEFA’s). Mean±SEM results are graphed. *<0.05 and **<0.005, control versus experimental diet; #<0.05 and ##<0.005, MCD versus Western diet.

Fig 2

Fig 2. Effects of MCD diet and Western diet on hepatic steatosis and liver enzymes.

(A). Liver to body weight (LBW) ratio, serum aminotransferases (ALT, AST) and alkaline phosphatase (ALP) from mice fed chow, MCD or Western diets. (B). H&E staining of representative liver sections from mice (left panels) and NASH patients with mild or severe fibrosis (right panels). (C). Oil-red O staining of representative liver sections from mice (left panels) and liver lipid levels (right). (D). qRT-PCR analysis of liver genes encoding lipid metabolic enzymes. Results normalized to chow-diet fed mice and graphed as mean±SEM. *<0.05 and **<0.005, control versus experimental diet; #<0.05 and ##<0.005, MCD versus Western diet.

Fig 3

Fig 3. Effects of MCD diet and Western diet on liver fibrosis and ductular reaction.

(A). Hepatic hydroxyl-proline content and qRT-PCR analysis of liver fibrosis and progenitor marker genes; (B). Liver sections from representative mice stained for markers of the fibroductular reaction (Sirius red, α-SMA, desmin, K19 and Sox-9) (left panels) and respective morphometry (right). Results normalized to chow-fed mice and graphed as mean±SEM. *<0.05 and **<0.005, control versus experimental diet; #<0.05 and ##<0.005, MCD versus Western diet.

Fig 4

Fig 4. Effects of MCD diet and Western diet on liver cell death, inflammation and oxidative stress.

(A). TUNEL assay and Western blot for caspase-2 and cleaved PARP; (B). qRT-PCR of macrophage markers (F4/80 and YM-1) and TNF-α (left). Immunohistochemistry for F4/80 and YM-1: Representative photos and morphometry (right). (C). qRT-PCR analysis of anti-oxidant enzymes (top) and immunohistochemistry plus morphometry for 4-hydroxynonenal (4-HNE) in representative mice (lower). Results normalized to chow-diet fed mice and graphed as mean±SEM. *<0.05 and **<0.005, control versus experimental diet; ##<0.005, MCD versus Western diet.

Fig 5

Fig 5. Effects of MCD diet and Western diet on liver cell stress and Hedgehog pathway.

(A). qRT-PCR analysis of relevant ER stress-related genes (left panel) and western blot analysis of GADD-153 (right panel); (C). Western blot analysis of the autophagy marker, LC3BII. (C). qRT-PCR analysis of Hedgehog ligands (Shh, Ihh), receptor (Patch), Hedgehog-regulated transcription factors (Gli1, Gli2), and Hedgehog-target genes (OPN, Hip-1) (left); Western blot analysis of Gli-2 (right). (D). Immunohistochemistry for osteopontin: sections from representative mice and morphometry. Results graphed as mean±SEM. *<0.05 and **<0.005, control versus experimental diet; #<0.05 and ##<0.005, MCD versus Western diet.

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References

    1. Clark JM, Brancati FL, Diehl AM (2003) The prevalence and etiology of elevated aminotransferase levels in the United States. Am J Gastroenterol 98: 960–967. - PubMed
    1. Loomba R, Sanyal AJ (2013) The global NAFLD epidemic. Nat Rev Gastroenterol Hepatol 10: 686–690. 10.1038/nrgastro.2013.171 - DOI - PubMed
    1. Singh S, Allen AM, Wang Z, Prokop LJ, Murad MH, Loomba R. (2015) Fibrosis Progression in Nonalcoholic Fatty Liver vs Nonalcoholic Steatohepatitis: A Systematic Review and Meta-analysis of Paired-Biopsy Studies. Clin Gastroenterol Hepatol 13: 643–654. 10.1016/j.cgh.2014.04.014 - DOI - PMC - PubMed
    1. Wong RJ, Cheung R, Ahmed A (2014) Nonalcoholic steatohepatitis is the most rapidly growing indication for liver transplantation in patients with hepatocellular carcinoma in the U.S. Hepatology 59: 2188–2195. 10.1002/hep.26986 - DOI - PubMed
    1. Itagaki H, Shimizu K, Morikawa S, Ogawa K, Ezaki T (2013) Morphological and functional characterization of non-alcoholic fatty liver disease induced by a methionine-choline-deficient diet in C57BL/6 mice. Int J Clin Exp Pathol 6: 2683–2696. - PMC - PubMed

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