Mesenteric adipose tissue B lymphocytes promote local and hepatic inflammation in non‐alcoholic fatty liver disease mice

Abstract Objectives β-Cryptoxanthin (BCX), a provitamin A carotenoid, is cleaved by carotenoid cleavage enzymes including β-carotene-15, 15′-oxygenase (BCO1) to generate vitamin A, and β-carotene-9′, 10′-oxygenase (BCO2) which yields bioactive apo-carotenoids. Dietary supplementation of BCX can prevent non-alcoholic fatty liver disease (NAFLD), which is the most common chronic liver disease worldwide. This study aimed to investigate whether BCX-mediated protection against NAFLD proceeds through the liver-mesenteric adipose tissue axis depending on the presence or absence of BCO1/BCO2. Methods Six-week-old male wild type (WT) mice (n = 30) and congenic BCO1−/−/BCO2−/− double KO (DKO) mice (n = 30) were randomly fed either a high-refined carbohydrate diet (HRCD, 66.5% CHO) or HRCD with BCX (10 mg/kg diet) for 24 weeks. Results Hepatic levels of BCX, but not retinol and retinyl palmitate, were significantly (P < 0.001) higher (33-fold) in the DKO mice than in the WT mice. BCX significantly reduced hepatic steatosis and total cholesterol levels in both WT and DKO mice in comparison with their HRCD counterparts (P < 0.01 and P < 0.001, respectively), albeit through different mechanisms. In the liver, BCX significantly (P < 0.05) down-regulated mRNA for cholesterol synthesis genes Hmgcr and Hmgs1 and nuclear bile acid receptor Fxr, and up-regulated cholesterol catabolism gene Cyp7a1 in DKO mice in comparison with their HRCD counterparts. Furthermore, BCX significantly (P < 0.05) up-regulated antioxidant enzymes Sod1 and Cat in DKO mice in comparison with HRCD littermates. In WT mice, BCX significantly (P < 0.05) up-regulated hepatic mRNA for cholesterol efflux gene Abcg5 and nuclear receptor Shp in comparison with their HRCD counterparts. In mesenteric adipose tissue, BCX significantly down-regulated (P < 0.05) the inflammatory cytokine Il6 and up-regulated fatty acid β-oxidation marker Acox1 and Sirt1 in DKO mice but significantly (P < 0.05) suppressed lipogenesis marker Acc1 in WT mice. Conclusions The protective effects of dietary BCX against HRCD-induced NAFLD are achieved through different molecular mechanisms in the liver-mesenteric adipose tissue axis and depend on the carotenoid cleavage enzymes. Funding Sources NIFA/AFRI (2017-67017-26363) and USDA/ARS (58-1950-0074).

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High-fructose feeding does not induce steatosis or non-alcoholic fatty liver disease in pigs

Scientific Reports ◽

10.1038/s41598-021-82208-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Nikolaj H. Schmidt ◽

Pia Svendsen ◽

Julián Albarrán-Juárez ◽

Søren K. Moestrup ◽

Jacob Fog Bentzon

Keyword(s):

Adipose Tissue ◽

Liver Disease ◽

Fatty Liver ◽

Fatty Liver Disease ◽

Histopathological Examination ◽

De Novo Lipogenesis ◽

Large Animal ◽

Alcoholic Fatty Liver ◽

High Fructose ◽

Alcoholic Fatty Liver Disease

AbstractNon-alcoholic fatty liver disease (NAFLD) is an increasingly prevalent condition that has been linked to high-fructose corn syrup consumption with induction of hepatic de novo lipogenesis (DNL) as the suggested central mechanism. Feeding diets very high in fructose (> 60%) rapidly induce several features of NAFLD in rodents, but similar diets have not yet been applied in larger animals, such as pigs. With the aim to develop a large animal NAFLD model, we analysed the effects of feeding a high-fructose (HF, 60% w/w) diet for four weeks to castrated male Danish Landrace-York-Duroc pigs. HF feeding upregulated expression of hepatic DNL proteins, but levels were low compared with adipose tissue. No steatosis or hepatocellular ballooning was seen on histopathological examination, and plasma levels of transaminases were similar between groups. Inflammatory infiltrates and the amount of connective tissue was slightly elevated in liver sections from fructose-fed pigs, which was corroborated by up-regulation of macrophage marker expression in liver homogenates. Supported by RNA-profiling, quantitative protein analysis, histopathological examination, and biochemistry, our data suggest that pigs, contrary to rodents and humans, are protected against fructose-induced steatosis by relying on adipose tissue rather than liver for DNL.

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Addressing the liver progenitor cell response and hepatic oxidative stress in experimental non-alcoholic fatty liver disease/non-alcoholic steatohepatitis using amniotic epithelial cells

Stem Cell Research & Therapy ◽

10.1186/s13287-021-02476-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Mihiri Goonetilleke ◽

Nathan Kuk ◽

Jeanne Correia ◽

Alex Hodge ◽

Gregory Moore ◽

...

Keyword(s):

Oxidative Stress ◽

Liver Disease ◽

Epithelial Cells ◽

Fatty Liver ◽

Progenitor Cells ◽

Fatty Liver Disease ◽

Hepatic Inflammation ◽

Alcoholic Fatty Liver ◽

And Oxidative Stress ◽

Alcoholic Fatty Liver Disease

Abstract Background Non-alcoholic fatty liver disease is the most common liver disease globally and in its inflammatory form, non-alcoholic steatohepatitis (NASH), can progress to cirrhosis and hepatocellular carcinoma (HCC). Currently, patient education and lifestyle changes are the major tools to prevent the continued progression of NASH. Emerging therapies in NASH target known pathological processes involved in the progression of the disease including inflammation, fibrosis, oxidative stress and hepatocyte apoptosis. Human amniotic epithelial cells (hAECs) were previously shown to be beneficial in experimental models of chronic liver injury, reducing hepatic inflammation and fibrosis. Previous studies have shown that liver progenitor cells (LPCs) response plays a significant role in the development of fibrosis and HCC in mouse models of fatty liver disease. In this study, we examined the effect hAECs have on the LPC response and hepatic oxidative stress in an experimental model of NASH. Methods Experimental NASH was induced in C57BL/6 J male mice using a high-fat, high fructose diet for 42 weeks. Mice received either a single intraperitoneal injection of 2 × 106 hAECs at week 34 or an additional hAEC dose at week 38. Changes to the LPC response and oxidative stress regulators were measured. Results hAEC administration significantly reduced the expansion of LPCs and their mitogens, IL-6, IFNγ and TWEAK. hAEC administration also reduced neutrophil infiltration and myeloperoxidase production with a concurrent increase in heme oxygenase-1 production. These observations were accompanied by a significant increase in total levels of anti-fibrotic IFNβ in mice treated with a single dose of hAECs, which appeared to be independent of c-GAS-STING activation. Conclusions Expansion of liver progenitor cells, hepatic inflammation and oxidative stress associated with experimental NASH were attenuated by hAEC administration. Given that repeated doses did not significantly increase efficacy, future studies assessing the impact of dose escalation and/or timing of dose may provide insights into clinical translation.

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