Ethyl 2-[2,3,4-Trimethoxy-6-(1-Octanoyl)Phenyl] Acetate (TMPA) Ameliorates Lipid Accumulation by Disturbing the Combination of LKB1 with Nur77 and Activating the AMPK Pathway in HepG2 Cells and Mice Primary Hepatocytes

  • Diabetes Metab Syndr Obes. 2021 Oct 2;14:4165-4177. doi: 10.2147/DMSO.S321246.
Xiaoyu Wang  1 ,  Guangbing Li  1  2 ,  Changfa Guo  3 ,  Jiayao Zhang  1 ,  Junjie Kong  1  2 ,  Jingyi He  1  2 ,  Feiyu Li  1 ,  Yong Liu  1 ,  Yang Yang  1 ,  Ziwen Lu  1 ,  Jun Liu  1  2
Affiliations
  • 1. Department of Hepatobiliary Surgery and Center of Organ Transplantation, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, People's Republic of China.
  • 2. Department of Hepatobiliary Surgery and Center of Organ Transplantation, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China.
  • 3. Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong University, Cheeloo College of Medicine, Jinan, Shandong, People's Republic of China.
PMID: 34629883 DOI: 10.2147/DMSO.S321246
Abstract

Background: The AMP-activated protein kinase alpha (AMPKα) pathway has widely been considered a key factor in energy metabolism. Ethyl 2-[2,3,4-trimethoxy-6-(1-octanoyl)phenyl] acetate (TMPA) is a novel AMPK agonist, which influences the stability of Nuclear Receptor Subfamily 4, Group A, Member 1 (Nur77)-serine-threonine kinase 11 (LKB1) in the nucleus. A recent study has determined that TMPA can ameliorate the reduction of Insulin resistance in type II db/db mice. However, the role of TMPA in hepatocyte lipid metabolism has not been elucidated.

Objective: To investigate whether TMPA could ameliorate liver lipid accumulation under the stimulation of free fatty acids (FFAs) in vitro.

Methods: We evaluated differences of Nur77 and AMPK pathway in mice fed a high-fat diet and those fed a normal diet. In vitro, TMPA was added to HepG2 cells and primary hepatocytes before FFAs stimulation. Oil red O staining, Nile red staining were used to evaluate lipid deposition. Western blot and immunofluorescence were used to quantify related proteins.

Results: Nur77, AMPKα, LKB1, 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), Acetyl-CoA Carboxylase phosphorylation (p-ACC), and carnitine palmitoyltransferase 1 (CPT1A) showed significant differences in vivo. Under the intervention of TMPA, HepG2 cells and primary hepatocytes showed considerable amelioration of lipid deposition and improved the expression of phosphorylated (p)-AMPKα (p-AMPKα), p-LKB1, p-ACC, and CPT1A. Furthermore, Western blotting and immunofluorescence studies indicated that LKB1 dramatically increased expression in the cytoplasm but decreased in the nucleus. Further, AMPKα phosphorylation (p-AMPKα) also showed a higher expression in cytoplasm instead of the nucleus.

Conclusion: TMPA ameliorated lipid accumulation by influencing the stability of Nur77-LKB1 in vitro.

Keywords
AMPK pathway; HepG2 cells; Nur77; ethyl 2-[2,3,4-trimethoxy-6-(1-octanoyl)phenyl] acetate; primary hepatocytes.
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