4-Hydroxynonenal impairs transforming growth factor-β1-induced elastin synthesis via epidermal growth factor receptor activation in human and murine fibroblasts

Free Radic Biol Med. 2014 Jun;71:427-36. doi: 10.1016/j.freeradbiomed.2014.02.015. Epub 2014 Feb 20.


Elastin is a long-lived protein and a key component of connective tissues. The tissular elastin content decreases during chronological aging, and the mechanisms underlying its slow repair are not known. Lipid oxidation products that accumulate in aged tissues may generate protein dysfunction. We hypothesized that 4-hydroxynonenal (4-HNE), a highly reactive α,β-aldehydic product generated from polyunsaturated fatty acid peroxidation, could contribute to inhibiting elastin repair by antagonizing the elastogenic signaling of transforming growth factor-β1 (TGF-β1) in skin fibroblasts. We report that a low 4-HNE concentration (2µmol/L) inhibits the upregulation of tropoelastin expression stimulated by TGF-β1 in human and murine fibroblasts. The study of signaling pathways potentially involved in the regulation of elastin expression showed that 4-HNE did not block the phosphorylation of Smad3, an early step of TGF-β1 signaling, but inhibited the nuclear translocation of Smad2. Concomitantly, 4-HNE modified and stimulated the phosphorylation of the epidermal growth factor receptor (EGFR) and subsequently ERK1/2 activation, leading to the phosphorylation/stabilization of the Smad transcriptional corepressor TGIF, which antagonizes TGF-β1 signaling. Inhibitors of EGFR (AG1478) and MEK/ERK (PD98059), and EGFR-specific siRNAs, reversed the inhibitory effect of 4-HNE on TGF-β1-induced nuclear translocation of Smad2 and tropoelastin synthesis. In vivo studies on aortas from aged C57BL/6 mice showed that EGFR is modified by 4-HNE, in correlation with an increased 4-HNE-adduct accumulation and decreased elastin content. Altogether, these data suggest that 4-HNE inhibits the elastogenic activity of TGF-β1, by modifying and activating the EGFR/ERK/TGIF pathway, which may contribute to altering elastin repair in chronological aging and oxidative stress-associated aging processes.

Keywords: 4-Hydroxynonenal; Aging; EGF receptor; Fibroblasts; Free radicals; TGF-β1; Tropoelastin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aging / genetics*
  • Aging / metabolism
  • Aging / pathology
  • Aldehydes / pharmacology*
  • Animals
  • Aorta / drug effects
  • Aorta / metabolism
  • Aorta / pathology
  • Cell Line, Transformed
  • Elastin / antagonists & inhibitors
  • Elastin / biosynthesis
  • Elastin / genetics*
  • ErbB Receptors / agonists
  • ErbB Receptors / genetics*
  • ErbB Receptors / metabolism
  • Fibroblasts / drug effects*
  • Fibroblasts / metabolism
  • Fibroblasts / pathology
  • Flavonoids / pharmacology
  • Gene Expression Regulation
  • Homeodomain Proteins
  • Humans
  • Lipid Peroxidation
  • Mice
  • Mitogen-Activated Protein Kinase 1 / genetics
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / genetics
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • Primary Cell Culture
  • Protein Transport / drug effects
  • Quinazolines / pharmacology
  • Repressor Proteins
  • Signal Transduction
  • Smad2 Protein / genetics
  • Smad2 Protein / metabolism
  • Smad3 Protein / genetics
  • Smad3 Protein / metabolism
  • Transforming Growth Factor beta1 / pharmacology*
  • Tyrphostins / pharmacology


  • Aldehydes
  • Flavonoids
  • Homeodomain Proteins
  • Quinazolines
  • Repressor Proteins
  • Smad2 Protein
  • Smad3 Protein
  • TGIF1 protein, human
  • Transforming Growth Factor beta1
  • Tyrphostins
  • RTKI cpd
  • Elastin
  • ErbB Receptors
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • 4-hydroxy-2-nonenal
  • 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one