Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0015695 (fatty liver)
 13,941 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human studies support the relationship between high intake of fructose-sweetened beverages and type 2 diabetes, but there is a debate on whether this effect is fructose-specific or it is merely associated to an excessive caloric intake. Here we investigate the effects of 2 months' supplementation to female rats of equicaloric 10% w/v fructose or glucose solutions on insulin sensitivity in target tissues. Fructose supplementation caused hepatic deposition of triglycerides and changed the fatty acid profile of this fraction, with an increase in monounsaturated and a decrease in polyunsaturated species, but did not cause inflammation and oxidative stress. Fructose but not glucose-supplemented rats displayed an abnormal glucose tolerance test, and did not show increased phosphorylation of V-akt murine thymoma viral oncogene homolog-2 (Akt) in white adipose tissue and liver after insulin administration. In skeletal muscle, phosphorylation of Akt and of Akt substrate of 160 kDA (AS160) was not impaired but the expression of the glucose transporter type 4 (GLUT4) in the plasma membrane was reduced only in fructose-fed rats. In conclusion, fructose but not glucose supplementation causes fatty liver without inflammation and oxidative stress and impairs insulin signaling in the three major insulin-responsive tissues independently from the increase in energy intake.
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PMID:Fructose, but not glucose, impairs insulin signaling in the three major insulin-sensitive tissues. 2719 5

Previous studies in humans have indicated that de novo lipogenesis contributes considerably to redundant lipid storage and steatosis in the liver of patients with nonalcoholic fatty liver disease (NAFLD), and then more severe complications occur. Recently, ellagic acid (EA) has drawn attention mainly due to its biological functionalities and a series of molecular targets. However, the molecular mechanism by which EA attenuates hepatic steatosis in individuals with undesirable hepatic genetic alterations remains rarely studied. Here, we evaluate the therapeutic efficacy of EA in a hepatic steatosis mouse model featuring elevated expression of sterol regulatory element-binding protein-1 (SREBP-1) and its downstream modulators of lipogenesis by hydrodynamic injection of v-akt murine thymoma viral oncogene homolog (AKT). Hematoxylin and eosin staining, oil red O staining, immunohistochemistry, immunoblotting, and quantitative polymerase chain reaction (qPCR) were performed for mechanistic investigations. Human hepatoma cell lines were used for mechanical validation in vitro. The results suggest that EA lightens the accumulation of lipids in hepatocytes of AKT-injected mice and an oleic acid-induced in vitro hepatic steatosis model. Mechanistically, EA administration decreases the expression of phospho-AKT (Thr308) and suppresses two effectors lying downstream of the AKT/mTORC1 pathway, ribosomal protein S6 (RPS6) and SREBP-1, in the AKT-injected mice. The consequence of the EA-mediated decrease of SREBP-1 is found to be a transcriptional and translational inhibition of fatty acid synthase (FASN), accompanied by the downregulation of acetyl-CoA carboxylase (ACC). Consistent with in vivo findings, EA efficiently represses the SREBP-1/FASN axis in vitro. Collectively, our study provides a novel mechanism whereby EA alleviates AKT-triggered hepatic de novo lipogenesis, indicating that EA might serve as a potential agent in the therapy of hepatic steatosis in patients with NAFLD and/or steatosis-associated complications, especially in that characterized by activation of AKT/mTORC1 signaling in the liver.
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PMID:Ellagic acid ameliorates AKT-driven hepatic steatosis in mice by suppressing de novo lipogenesis via the AKT/SREBP-1/FASN pathway. 3112 44