Luteolin-7-glucoside inhibits IL-22/STAT3 pathway, reducing proliferation, acanthosis, and inflammation in keratinocytes and in mouse psoriatic model

Cell Death Dis. 2016 Aug 18;7(8):e2344. doi: 10.1038/cddis.2016.201.

Abstract

The epidermis is a dynamic tissue in which keratinocytes proliferate in the basal layer and undergo a tightly controlled differentiation while moving into the suprabasal layers. The balance between keratinocyte proliferation, differentiation, and death is essential, and its perturbation can result in pathological changes. Some common skin diseases, such as psoriasis, are characterized by hyperproliferation accompanied by inflammatory reactions, suggesting that molecules with topical anti-inflammatory and ROS scavenging abilities may be useful for their treatment. Here we investigate the potential of the flavone Luteolin-7-glucoside (LUT-7G) as a treatment for psoriasis. We show that LUT-7G leads to a modification of the cell cycle and the induction of keratinocyte differentiation, with modification of energy, fatty acid, and redox metabolism. LUT-7G treatment also neutralizes the proliferative stimulus induced by the proinflammatory cytokines IL-22 and IL-6 in HEKn. Moreover, in the Imiquimod (IMQ) mouse model of psoriasis, topical administration of LUT-7G leads to a marked reduction of acanthosis and re-expression of epidermal differentiation markers. Dissection of the IL-22 signalling pathway, activated by IMQ treatment, demonstrates that LUT-7G impairs the nuclear translocation of phosphorylated (activated) STAT3, blocking the IL-22 signalling cascade. Thus LUT-7G appears to be a promising compound for the treatment of hyperproliferative and inflammatory skin diseases, such as psoriasis.

MeSH terms

  • Acanthosis Nigricans / complications
  • Acanthosis Nigricans / drug therapy*
  • Acanthosis Nigricans / metabolism
  • Acanthosis Nigricans / pathology
  • Aminoquinolines / pharmacology
  • Aminoquinolines / therapeutic use
  • Animals
  • Cell Differentiation / drug effects
  • Cell Nucleus / drug effects
  • Cell Nucleus / metabolism
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Cellular Senescence / drug effects
  • Disease Models, Animal
  • Glucosides / pharmacology*
  • Glucosides / therapeutic use
  • Humans
  • Imiquimod
  • Immunohistochemistry
  • Inflammation / complications
  • Inflammation / drug therapy*
  • Inflammation / pathology
  • Interleukin-22
  • Interleukins / metabolism*
  • Keratinocytes / drug effects
  • Keratinocytes / metabolism
  • Keratinocytes / pathology*
  • Lipids / biosynthesis
  • Luteolin / pharmacology*
  • Luteolin / therapeutic use
  • Mice, Inbred C57BL
  • Oxidation-Reduction / drug effects
  • Phenotype
  • Protein Transport / drug effects
  • Psoriasis / drug therapy*
  • Psoriasis / metabolism
  • Psoriasis / pathology*
  • STAT3 Transcription Factor / metabolism*
  • Signal Transduction / drug effects

Substances

  • Aminoquinolines
  • Glucosides
  • Interleukins
  • Lipids
  • STAT3 Transcription Factor
  • luteolin-7-glucoside
  • Luteolin
  • Imiquimod