Co-option of PPARα in the regulation of lipogenesis and fatty acid oxidation in CLA-induced hepatic steatosis

J Cell Physiol. 2021 Jun;236(6):4387-4402. doi: 10.1002/jcp.30157. Epub 2020 Nov 13.

Abstract

Nonalcoholic-fatty-liver-disease (NAFLD) is the result of imbalances in hepatic lipid partitioning and is linked to dietary factors. We demonstrate that conjugated linoleic acid (CLA) when given to mice as a dietary supplement, induced an enlarged liver, hepatic steatosis, and increased plasma levels of fatty acid (FA), alanine transaminase, and triglycerides. The progression of NAFLD and insulin resistance was reversed by GW6471 a small-molecule antagonist of peroxisome proliferator-activated receptor α (PPARα). Transcriptional profiling of livers revealed that the genes involved in FA oxidation and lipogenesis as two core gene programs controlled by PPARα in response to CLA and GW6471 including Acaca and Acads. Bioinformatic analysis of PPARα ChIP-seq data set and ChIP-qPCR showed that GW6471 blocks PPARα binding to Acaca and Acads and abolishes the PPARα-mediated local histone modifications of H3K27ac and H3K4me1 in CLA-treated hepatocytes. Thus, our findings reveal a dual role of PPARα in the regulation of lipid homeostasis and highlight its druggable nature in NAFLD.

Keywords: GW6471; PPARα; conjugated linoleic acid; fatty acid oxidation; hepatic steatosis; lipogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetyl-CoA Carboxylase / genetics
  • Acetyl-CoA Carboxylase / metabolism
  • Acyl-CoA Dehydrogenase / genetics
  • Acyl-CoA Dehydrogenase / metabolism
  • Animals
  • Cells, Cultured
  • Disease Models, Animal
  • Fatty Acids / metabolism*
  • Gene Expression Regulation, Enzymologic
  • Hepatocytes / drug effects
  • Hepatocytes / metabolism*
  • Hepatocytes / pathology
  • Histones / metabolism
  • Insulin Resistance
  • Linoleic Acids, Conjugated
  • Lipogenesis* / drug effects
  • Liver / drug effects
  • Liver / metabolism*
  • Liver / pathology
  • Male
  • Mice
  • Non-alcoholic Fatty Liver Disease / chemically induced
  • Non-alcoholic Fatty Liver Disease / metabolism*
  • Non-alcoholic Fatty Liver Disease / pathology
  • Non-alcoholic Fatty Liver Disease / prevention & control
  • Oxazoles / pharmacology
  • Oxidation-Reduction
  • PPAR alpha / antagonists & inhibitors
  • PPAR alpha / genetics
  • PPAR alpha / metabolism*
  • Signal Transduction
  • Transcriptional Activation
  • Tyrosine / analogs & derivatives
  • Tyrosine / pharmacology

Substances

  • Fatty Acids
  • GW 6471
  • Histones
  • Linoleic Acids, Conjugated
  • Oxazoles
  • PPAR alpha
  • Ppara protein, mouse
  • Tyrosine
  • Acyl-CoA Dehydrogenase
  • Acaca protein, mouse
  • Acetyl-CoA Carboxylase