The Inhibitory Effects of Anti-Oxidants on Ultraviolet-Induced Up-Regulation of the Wrinkling-Inducing Enzyme Neutral Endopeptidase in Human Fibroblasts

PLoS One. 2016 Sep 20;11(9):e0161580. doi: 10.1371/journal.pone.0161580. eCollection 2016.

Abstract

We recently reported that the over-expression of skin fibroblast-derived neutral endopeptidase (NEP) plays a pivotal role in impairing the three-dimensional architecture of dermal elastic fibers during the biological mechanism of ultraviolet (UV)-induced skin wrinkling. In that process, a UVB-associated epithelial-mesenchymal cytokine interaction as well as a direct UVA-induced cellular stimulation are associated with the up-regulation of NEP in human fibroblasts. In this study, we characterized the mode of action of ubiquinol10 which may abrogate the up-regulation of NEP by dermal fibroblasts, resulting in a reported in vivo anti-wrinkling action, and compared that with 3 other anti-oxidants, astaxanthin (AX), riboflavin (RF) and flavin mononucleotide (FMN). Post-irradiation treatment with all 4 of those anti-oxidants elicited an interrupting effect on the UVB-associated epithelial-mesenchymal cytokine interaction leading to the up-regulation of NEP in human fibroblasts but with different modes of action. While AX mainly served as an inhibitor of the secretion of wrinkle-inducing cytokines, such as interleukin-1α (IL-1α) and granulocyte macrophage colony stimulatory factor (GM-CSF) in UVB-exposed epidermal keratinocytes, ubiquinol10, RF and FMN predominantly interrupted the IL-1α and GM-CSF-stimulated expression of NEP in dermal fibroblasts. On the other hand, as for the UVA-associated mechanism, similar to the abrogating effects reported for AX and FMN, ubiquinol10 but not RF had the potential to abrogate the increased expression of NEP and matrix-metalloproteinase-1 in UVA-exposed human fibroblasts. Our findings strongly support the in vivo anti-wrinkling effects of ubiquinol10 and AX on human and animal skin and provide convincing proof of the UV-induced wrinkling mechanism that essentially focuses on the over-expression of NEP by dermal fibroblasts as an intrinsic causative factor.

MeSH terms

  • Antioxidants / pharmacology*
  • Cell Line
  • Cells, Cultured
  • Cytokines / metabolism
  • Fibroblasts / drug effects*
  • Fibroblasts / enzymology
  • Fibroblasts / radiation effects*
  • Granulocyte-Macrophage Colony-Stimulating Factor / metabolism
  • Humans
  • Neprilysin / genetics*
  • Neprilysin / metabolism
  • Skin Aging / drug effects
  • Skin Aging / radiation effects
  • Ubiquinone / analogs & derivatives*
  • Ubiquinone / pharmacology
  • Ultraviolet Rays
  • Up-Regulation / drug effects*
  • Up-Regulation / radiation effects*

Substances

  • Antioxidants
  • Cytokines
  • Ubiquinone
  • ubiquinol-10
  • Granulocyte-Macrophage Colony-Stimulating Factor
  • Neprilysin

Grants and funding

HN was in Tokyo University of Technology at that time and HN is now in Toyo Beauty Co. Ltd. Therefore, Toyo Beauty Co. Ltd did not support any funding for these studies in this manuscript. Therefore, we state that there was no funding for supporting this study. The author(s) received no specific funding for this work.