Modulation of hepatic inflammation and energy-sensing pathways in the rat liver by high-fructose diet and chronic stress.
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© 2018 Springer-Verlag GmbH Germany, part of Springer Nature
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PURPOSE High-fructose consumption and chronic stress are both associated with metabolic inflammation and insulin resistance. Recently, disturbed activity of energy sensor AMP-activated protein kinase (AMPK) was recognized as mediator between nutrient-induced stress and inflammation. Thus, we analyzed the effects of high-fructose diet, alone or in combination with chronic stress, on glucose homeostasis, inflammation and expression of energy sensing proteins in the rat liver. METHODS In male Wistar rats exposed to 9-week 20% fructose diet and/or 4-week chronic unpredictable stress we measured plasma and hepatic corticosterone level, indicators of glucose homeostasis and lipid metabolism, hepatic inflammation (pro- and anti-inflammatory cytokine levels, Toll-like receptor 4, NLRP3, activation of NFκB, JNK and ERK pathways) and levels of energy-sensing proteins AMPK, SIRT1 and peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α). RESULTS High-fructose diet led to glucose intolerance, activation of NFκB and JNK pathways and increased intrahepatic IL-1β, TNFα and inhibitory phosphorylation of insulin receptor substrate 1 on Ser307. It also decreased phospho-AMPK/AMPK ratio and increased SIRT1 expression. Stress alone increased plasma and hepatic corticosterone but did not influence glucose tolerance, nor hepatic inflammatory or energy-sensing proteins. After the combined treatment, hepatic corticosterone was increased, glucose tolerance remained preserved, while hepatic inflammation was partially prevented despite decreased AMPK activity. CONCLUSION High-fructose diet resulted in glucose intolerance, hepatic inflammation, decreased AMPK activity and reduced insulin sensitivity. Chronic stress alone did not exert such effects, but when applied together with high-fructose diet it could partially prevent fructose-induced inflammation, presumably due to increased hepatic glucocorticoids.
This is a post-peer-review, pre-copyedit version of an article published in European Journal of Nutrition. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00394-018-1730-1
Keywords:AMP-activated protein kinase; Dietary fructose; Inflammation; Rat liver; Stress
Source:European Journal of Nutrition, 2018, 1-17
- Role of steroid hormones in neuroendocrine adaptation to stress and pathophysiology of metabolic syndrome - molecular mechanisms and clinical implications (RS-41009)
- SCOPES JRP (Grant no. IZ73ZO_152331)