Mesencephalic astrocyte-derived neurotrophic factor ameliorates steatosis in HepG2 cells by regulating hepatic lipid metabolism.

Content Provider	Europe PMC
Author	He, Miao Wang, Cong Long, Xiao-Hong Peng, Jia-Jia Liu, Dong-Fang Yang, Gang-Yi Jensen, Michael D Zhang, Li-Li
Copyright Year	2020
Abstract	BACKGROUNDNonalcoholic fatty liver disease (NAFLD) is a global metabolism-associated liver disease. Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a newly discovered secreted protein that is involved in metabolic homeostasis. However, much remains to be discovered about its function in hepatic lipid metabolism; thus, we assessed whether MANF could regulate hepatic metabolism.AIMTo establish in vivo and in vitro NAFLD models to explore the role of MANF in hepatic lipid metabolism.METHODSHepG2 cells treated with free fatty acids (FFAs) and ob/ob mice were used as NAFLD models. Liver tissues collected from wild type and ob/ob mice were used to detect MANF expression. Cells were treated with FFAs for different durations. Moreover, we used lentiviral constructs to establish overexpression and knockdown cell models in order to interfere with MANF expression levels and observe whether MANF influences hepatic steatosis. Western blot analysis and quantitative real-time PCR were used to detect protein and gene expression, and oil red O staining was used to visualize intracellular lipid droplets.RESULTSHepatic MANF protein and mRNA expression in wild type mice were 10-fold and 2-fold higher, respectively, than those in ob/ob mice. The MANF protein was temporarily increased by 1.3-fold after stimulation with FFAs for 24 h and gradually decreased to 0.66-fold that of the control at the 72 h time point in HepG2 cells. MANF deficiency upregulated the expression of genes involved in fatty acid synthesis, cholesterol synthesis, and fatty acid uptake and aggravated HepG2 cell steatosis, while MANF overexpression inhibited fatty acid synthesis and uptake and cholesterol synthesis, and rescued HepG2 cells from FFAs-induced steatosis. Furthermore, a significant decrease in triglyceride levels was observed in the MANF overexpression group compared with the control group (0.4288 ± 0.0081 mmol/g vs 0.3746 ± 0.0121 mmol/g, P < 0.05) upon FFAs treatment. There was also a 17% decrease in intracellular total cholesterol levels between the MANF overexpression group and the control group (0.1301 ± 0.0059 mmol/g vs 0.1088 ± 0.0009 mmol/g, P < 0.05) upon FFAs treatment. Moreover, MANF suppressed lipid deposition in HepG2 cells.CONCLUSIONOur findings indicate that MANF improves the phenotype of liver cell steatosis and may be a potential therapeutic target in hepatic steatosis processes.
ISSN	10079327
Volume Number	26
PubMed Central reference number	PMC7081003
Issue Number	10
PubMed reference number	32205994
Journal	World Journal of Gastroenterology [World J. Gastroenterol]
e-ISSN	22192840
DOI	10.3748/wjg.v26.i10.1029
Language	English
Publisher	Baishideng Publishing Group Inc
Publisher Date	2020-03-01
Access Restriction	Open
Rights License	This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
Subject Keyword	Mesencephalic astrocyte-derived neurotrophic factor Nonalcoholic fatty liver disease Hepatic steatosis Lipogenesis In vitro HepG2
Content Type	Text
Resource Type	Article
Subject	Gastroenterology