Subchronic GenX Exposure Induces Hepatic Alterations Accompanied by Changes in PPAR-Related Lipid Metabolism and Autophagy-Related Proteins in Adult Male C57BL/6J Mice: Partial Attenuation by Chlorogenic Acid.

Background

2,3,3,3-Tetrafluoro-2-(heptafluoropropoxy)propanoic acid (GenX) is a perfluoroether carboxylic acid that has been detected in drinking water sources. Its potential hepatotoxicity has raised concern, although the associated molecular alterations remain incompletely understood. Chlorogenic acid (CGA), a naturally occurring polyphenol, has been reported to affect oxidative stress and metabolic homeostasis.

Methods

Adult male C57BL/6J mice were exposed to GenX (2 mg/kg/day) with or without CGA (30 mg/kg/day) by gavage for 12 weeks. AML12 cells were treated with GenX (10-800 μM) for 24 or 48 h to assess cell viability, and intracellular lipid accumulation was evaluated after exposure to 200 μM GenX for 24 h.

Results

GenX exposure induced hepatomegaly, microvesicular steatosis, inflammatory cell infiltration, and a reduction in hepatic glycogen stores. It also decreased hepatic glutathione concentrations and increased hepatic malondialdehyde concentrations. Serum alanine aminotransferase, aspartate aminotransferase, total cholesterol, and triglyceride levels were elevated. In AML12 cells, GenX increased intracellular lipid accumulation, as assessed by Oil Red O staining. Transcriptomic analysis identified significant enrichment of the peroxisome proliferator-activated receptor (PPAR) signaling pathway. Consistently, GenX altered the expression of genes and proteins involved in lipogenesis, fatty acid uptake, lipid storage, and fatty acid oxidation, suggesting disturbed PPAR-related lipid metabolic regulation. Moreover, the decreased p-mTOR/mTOR ratio, increased LC3-II/I, and overexpression of Beclin1, p62, and inflammatory mediators in the GenX group might suggest changes in autophagy-related proteins and inflammatory response. CGA coadministration partially attenuated several GenX-induced hepatic alterations, including liver enlargement, hepatic lipid accumulation, lipid peroxidation, and changes in selected autophagy- and inflammation-related proteins.

Conclusions

Subchronic GenX exposure-induced adverse hepatic effects might be associated with disrupted PPAR-related lipid metabolic regulation, oxidative stress, inflammatory responses, and changes in autophagy-related proteins. CGA might exert potential modulatory effects.