Autophagy Suppresses Toll-Like Receptor 3-Mediated Inflammatory Reaction in Human Epidermal Keratinocytes

Biomed Res Int. 2020 May 1:2020:4584626. doi: 10.1155/2020/4584626. eCollection 2020.

Abstract

Autophagy, one mechanism of programmed cell death, is fundamental to cellular homeostasis. Previous studies have identified autophagy as a novel mechanism by which cytokines control the immune response. However, its precise role in immune-related inflammatory skin diseases such as psoriasis remains unclear. Thus, this study explored the functional role of autophagy in psoriatic inflammation of epidermal keratinocytes. Strong light chain 3 immunoreactivity was observed in epidermal keratinocytes of both human psoriatic lesions and imiquimod-induced mice psoriatic model, and it was readily induced by polycytidylic acid (poly (I:C)), which stimulates Toll-like receptor 3 (TLR3), in human epidermal keratinocytes in vitro. Rapamycin-induced activation of autophagy significantly reduced poly (I:C)-induced inflammatory reaction, whereas, inhibition of autophagy by 3-methyladeine increased that. Our results indicate that the induction of autophagy may attenuate TLR3-mediated immune responses in human epidermal keratinocytes, thus providing novel insights into the mechanisms underlying the development of inflammatory skin diseases including psoriasis.

MeSH terms

  • Animals
  • Autophagy / physiology*
  • Cells, Cultured
  • Cytokines / metabolism
  • Humans
  • Inflammation / metabolism*
  • Keratinocytes / metabolism*
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Psoriasis / metabolism*
  • Skin / cytology
  • Toll-Like Receptor 3 / metabolism*

Substances

  • Cytokines
  • TLR3 protein, human
  • TLR3 protein, mouse
  • Toll-Like Receptor 3