The oxidative stress product carboxyethylpyrrole potentiates TLR2/TLR1 inflammatory signaling in macrophages

PLoS One. 2014 Sep 3;9(9):e106421. doi: 10.1371/journal.pone.0106421. eCollection 2014.

Abstract

Oxidative stress is key in the pathogenesis of several diseases including age-related macular degeneration (AMD), atherosclerosis, diabetes, and Alzheimer's disease. It has previously been established that a lipid peroxidation product, carboxyethylpyrrole (CEP), accumulates in the retinas of AMD patients. Retinal infiltrating macrophages also accumulate in the retinas of both AMD patients and in a murine model of AMD. We therefore investigated the ability of CEP-adducts to activate innate immune signaling in murine bone-marrow derived macrophages (BMDMs). We found that CEP specifically synergizes with low-dose TLR2-agonists (but not agonists for other TLRs) to induce production of inflammatory cytokines. Moreover, CEP selectively augments TLR2/TLR1-signaling instead of TLR2/TLR6-signaling. These studies uncover a novel synergistic inflammatory relationship between an endogenously produced oxidation molecule and a pathogen-derived product, which may have implications in the AMD disease process and other oxidative stress-driven pathologies.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Gene Expression Regulation
  • Humans
  • Immunity, Innate / drug effects
  • Inflammation / genetics
  • Inflammation / immunology
  • Inflammation / pathology
  • Lipid Peroxidation / drug effects
  • Macrophages / drug effects
  • Macrophages / immunology
  • Macular Degeneration / genetics
  • Macular Degeneration / immunology*
  • Macular Degeneration / pathology
  • Mice
  • Oxidative Stress / drug effects
  • Pyrroles / administration & dosage*
  • Pyrroles / metabolism
  • Signal Transduction / drug effects
  • Toll-Like Receptor 1 / biosynthesis*
  • Toll-Like Receptor 1 / genetics
  • Toll-Like Receptor 2 / biosynthesis*
  • Toll-Like Receptor 2 / genetics
  • Toll-Like Receptor 6 / biosynthesis
  • Toll-Like Receptor 6 / genetics

Substances

  • Pyrroles
  • Tlr2 protein, mouse
  • Tlr6 protein, mouse
  • Toll-Like Receptor 1
  • Toll-Like Receptor 2
  • Toll-Like Receptor 6