Fatty Acids Induce a Pro-Inflammatory Gene Expression Profile in Huh-7 Cells That Attenuates the Anti-HCV Action of Interferon

J Interferon Cytokine Res. 2015 May;35(5):392-400. doi: 10.1089/jir.2014.0165. Epub 2015 Jan 14.

Abstract

The pathogenesis of nonalcoholic steatohepatitis is primarily an immune-driven disease and a known factor associated with treatment failure of chronic hepatitis C with interferon (IFN) and ribavirin. We studied the hepatocyte response in a model of steatosis at the transcriptome level and the antiviral action of IFN against hepatitis C virus (HCV) in this setting. In this study, we have shown that lipid loading (oleic acid and palmitic acid, OA:PA) of Huh-7 cells leads to increased expression of classical interferon-stimulated genes (ISGs) and NF-κβ-dependent pro-inflammatory genes. A selective blocker of Toll-like receptor (TLR)2 signaling suppressed NF-κβ promoter activity by OA:PA, suggesting that free fatty acids (FFAs) act as a TLR2 pathogen-associated molecular pattern. Furthermore, in the presence of OA:PA, IFN stimulation and HCV infection (Jc1) increased ISG expression. Somewhat counterintuitive to the increase in ISGs, the anti-HCV activity of IFN was attenuated in the presence of OA:PA. Interestingly, the combination of OA:PA, HCV, and IFN-α stimulation resulted in a significant increase in CXCL8 protein production, a cytokine known to have anti-IFN modulating activity. Thus, in an in vitro model of steatosis, the FFAs OA and PA drive an NF-κβ-dependent inflammatory and ISG gene expression profile via TLR2 activation. Furthermore, FFA synergistically increases IFN-driven gene expression that may account for HCV treatment failure in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • Cluster Analysis
  • Drug Synergism
  • Fatty Acids / metabolism*
  • Fatty Acids / pharmacology
  • Fatty Liver / etiology
  • Fatty Liver / metabolism
  • Gene Expression Profiling
  • Gene Expression Regulation / drug effects
  • Hepacivirus / drug effects
  • Hepacivirus / physiology*
  • Hepatitis C, Chronic / genetics*
  • Hepatitis C, Chronic / metabolism*
  • Humans
  • Interferons / metabolism*
  • Interferons / pharmacology
  • NF-kappa B / metabolism
  • Oleic Acid / pharmacology
  • Palmitic Acid / pharmacology
  • Toll-Like Receptor 2 / metabolism
  • Transcriptome*
  • Virus Replication / drug effects

Substances

  • Fatty Acids
  • NF-kappa B
  • Toll-Like Receptor 2
  • Oleic Acid
  • Palmitic Acid
  • Interferons