The Different Mechanisms of Lipid Accumulation in Hepatocytes Induced by Oleic Acid/Palmitic Acid and High-Fat Diet

Abstract

Non-alcoholic fatty liver disease (NAFLD) is the primary chronic liver disease worldwide, mainly manifested by hepatic steatosis. Hepatic lipids may be derived from dietary intake, plasma free fatty acid (FFA) uptake, or hepatic de novo lipogenesis (DNL). Currently, cellular and animal models of hepatocellular steatosis are widely used to study the pathogenesis of NAFLD and to investigate therapeutic agents. However, whether there are differences between the in vivo and in vitro models of the mechanisms that cause lipid accumulation has not been reported. We used OA/PA-induced NCTC 1469 cells and high-fat-diet-fed C57BL/6J mice to simulate a hepatocyte steatosis model of NAFLD and to detect indicators related to FFA uptake and DNL. In addition, when serological indicators were analysed in the mouse model, it was found that serum FASN levels decreased. The results revealed that, in the cellular model, indicators related to DNL were decreased, FASN enzyme activity was unchanged, and indicators related to FFA uptake were increased, including the high expression of CD36; while, in the animal model, indicators related to both FFA uptake and de novo synthesis were increased, including the high expression of CD36 and the increased protein levels of FASN with enhanced enzyme activity. In addition, after an analysis of the serological indicators in the mouse model, it was found that the serum levels of FASN were reduced. In conclusion, the OA/PA-induced cellular model can be used to study the mechanism of FFA uptake, whereas the high-fat-diet-induced mouse model can be used to study the mechanism of FFA uptake and DNL. Combined treatment with CD36 and FASN may be more effective against NAFLD. FASN in the serum can be used as one of the indicators for the clinical diagnosis of NAFLD.

Sea Buckthorn Polyphenols Alleviate High-Fat-Diet-Induced Metabolic Disorders in Mice via Reprograming Hepatic Lipid Homeostasis Owing to Directly Targeting Fatty Acid Synthase

“…Subsequently, the membranes were sealed with 5% (w/ v) skimmed milk in TBST at 20 °C for 1 h, incubated overnight at 4 °C with the primary antibodies (target protein: FAS, Cell Signaling Technology, Danvers, MA; internal control protein: Vinculin, Proteintech, Rosemont, IL), and then incubated with the secondary antibodies for 1 h. Finally, the proteins were visualized using enhanced chemiluminescence and autoradiographed. 25 Molecular Docking. As a targeted receptor, the crystal structure of human FAS was obtained from the Protein Data Bank (PDB, https://www.rcsb.org/), and the chemical structures of its potential ligands were obtained from the PubChem (http://www.ncbi.nlm.nih.…”

“…The total extracted proteins were quantified using a BCA protein detection kit (Beyotime Co. Ltd., Shanghai, China), separated using 6% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and transferred onto poly­(vinylidene fluoride) (PVDF) membranes. Subsequently, the membranes were sealed with 5% (w/v) skimmed milk in TBST at 20 °C for 1 h, incubated overnight at 4 °C with the primary antibodies (target protein: FAS, Cell Signaling Technology, Danvers, MA; internal control protein: Vinculin, Proteintech, Rosemont, IL), and then incubated with the secondary antibodies for 1 h. Finally, the proteins were visualized using enhanced chemiluminescence and autoradiographed …”

Inhibition of fatty acid synthase in fibroblasts alleviates pulmonary fibrosis through the regulation of β- catenin

“…Fatty acid synthase (FASN) is a ubiquitous and cytosolic enzyme [6]. The enzyme catalyzes the rst step of de novo lipogenesis (DNL), which can condense one acetyl-CoA and seven malonyl-CoA molecules to a 16-carbon palmitate acid (PA) [7]. Normal cells in adult tissues generally express low to moderate levels of FASN.…”