In vitro toxicity of perfluorooctane sulfonate on rat liver hepatocytes: probability of distructive binding to CYP 2E1 and involvement of cellular proteolysis

Environ Sci Pollut Res Int. 2017 Oct;24(29):23382-23388. doi: 10.1007/s11356-017-9908-2. Epub 2017 Aug 25.

Abstract

Perfluorooctanesulfonate (PFOS), an anthropogenic fluorosurfactant, is one of the most common global pollutants. PFOS is used in various consumer products to provide soil, oil, and water resistance to materials used in clothing, upholstery, and food packaging. PFOS is persistent, bioaccumulative, and toxic to mammalian species. In this study, the cellular mechanisms involved in PFOS hepatotoxicity were evaluated. For this purpose, we determined oxidative stress markers including cell lysis, ROS generation, lipid peroxidation, glutathione depletion, mitochondrial membrane potential decrease, lysosomal membrane leakiness, and cellular proteolysis. Our results demonstrated that PFOS liver cytotoxicity was associated with reactive oxygen species (ROS) formation and lipid peroxidation in isolated rat hepatocytes. Incubation of hepatocytes with PFOS caused rapid depletion of hepatocyte glutathione (GSH), an important marker of cellular oxidative stress. Most of the PFOS-induced GSH depletion could be attributed to the expulsion of glutathione disulfide (GSSG). PFOS hepatotoxicity was inhibited by antioxidants and ROS scavengers, mitochondrial permeability transition (MPT) pore sealing agents, and endocytosis inhibitors. Our results suggest that PFOS hepatotoxicity might be the result of oxidative stress-induced lysosomal membrane leakiness and cellular proteolysis in rat hepatocytes.

Keywords: PFOS hepatotoxicity; Perfluorinated compounds (PFCs); Perfluorooctanesulfonate.

MeSH terms

  • Alkanesulfonic Acids / toxicity*
  • Animals
  • Cell Survival / drug effects
  • Cells, Cultured
  • Cytochrome P-450 CYP2E1 / metabolism*
  • Environmental Pollutants / toxicity*
  • Fluorocarbons / toxicity*
  • Hepatocytes / drug effects*
  • Hepatocytes / enzymology
  • Male
  • Oxidation-Reduction
  • Oxidative Stress / drug effects
  • Protein Binding
  • Proteolysis / drug effects*
  • Rats, Sprague-Dawley

Substances

  • Alkanesulfonic Acids
  • Environmental Pollutants
  • Fluorocarbons
  • perfluorooctane sulfonic acid
  • Cytochrome P-450 CYP2E1