PPARα/ACOX1 as a novel target for hepatic lipid metabolism disorders induced by per- and polyfluoroalkyl substances: An integrated approach

Environ Int. 2023 Aug:178:108138. doi: 10.1016/j.envint.2023.108138. Epub 2023 Aug 8.


Background: Per- and polyfluoroalkyl substances (PFAS) are persistent and ubiquitous environmental contaminants with well-documented hepatotoxicity. However, the mechanistic linkage between PFAS exposure and non-alcoholic fatty liver disease (NAFLD) remains largely elusive.

Objectives: This study aimed to explore PFAS-to-NAFLD link and the relevant molecular mechanisms.

Methods: The cross-sectional analyses using National Health and Nutrition Examination Survey (NHANES) data were conducted to investigate the association between PFAS exposure and NAFLD. A combination of in silico toxicological analyses, bioinformatics approaches, animal experiments, and in vitro assays was used to explore the molecular initiating events (MIEs) and key events (KEs) in PFAS-induced hepatic lipid metabolism disorders.

Results: The cross-sectional analyses with NHANES data revealed the significant association between PFAS exposure and hepatic steatosis/NAFLD. The in silico toxicological analyses showed that PPARα activation induced by perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), prototypical representatives of PFAS, is the critical MIE associated with NAFLD-predominant liver diseases. Transcriptome-based bioinformatic annotation and analyses identified that transcriptional upregulation of hepatic acyl-CoA oxidase 1 (ACOX1) in PPARα-regulated peroxisomal β-oxidation pathway was the KE involved with PFOA/PFOS-perturbed hepatic lipid metabolic pathways in humans, mice and rats. The in vivo and in vitro assays further verified that ACOX1-mediated oxidative stress contributed to mitochondrial compromise and lipid accumulation in PFOA/PFOS-exposed mouse hepatocytes, which could be mitigated by co-treatment with ACOX1 inhibitor and mitochondria ROS scavenger. Additionally, we observed that besides PFOA and PFOS, hepatic ACOX1 exhibited good-fit response to short-term exposures of long-chain (C7-C10) perfluoroalkyl carboxylic acids (PFHpA, PFNA, PFDA) and perfluoroalkyl sulfonic acids (PFHpS, PFDS) in human hepatocyte spheroids through benchmark dose (BMD) modeling.

Conclusion: Our study unveils a novel molecular target for PFAS-induced hepatic lipid metabolic disorders, shedding new light on prediction, assessment, and mitigation of PFAS hepatotoxicity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkanesulfonic Acids* / toxicity
  • Animals
  • Caprylates
  • Chemical and Drug Induced Liver Injury*
  • Cross-Sectional Studies
  • Environmental Pollutants* / toxicity
  • Fluorocarbons* / toxicity
  • Humans
  • Lipid Metabolism
  • Lipid Metabolism Disorders*
  • Mice
  • Non-alcoholic Fatty Liver Disease*
  • Nutrition Surveys
  • PPAR alpha / genetics
  • Rats


  • PPAR alpha
  • perfluorooctane sulfonic acid
  • Alkanesulfonic Acids
  • perfluorooctanoic acid
  • Caprylates
  • Fluorocarbons
  • Environmental Pollutants