Activation of TLR3 in keratinocytes increases expression of genes involved in formation of the epidermis, lipid accumulation, and epidermal organelles

J Invest Dermatol. 2013 Aug;133(8):2031-40. doi: 10.1038/jid.2013.39. Epub 2013 Feb 28.

Abstract

Injury to the skin, and the subsequent release of noncoding double-stranded RNA (dsRNA) from necrotic keratinocytes, has been identified as an endogenous activator of Toll-like receptor 3 (TLR3). As changes in keratinocyte growth and differentiation follow injury, we hypothesized that TLR3 might trigger some elements of the barrier repair program in keratinocytes. dsRNA was observed to induce TLR3-dependent increases in human keratinocyte mRNA abundance for ABCA12 (ATP-binding cassette, sub-family A, member 12), glucocerebrosidase, acid sphingomyelinase, and transglutaminase 1. Additionally, treatment with dsRNA resulted in increases in sphingomyelin and morphologic changes including increased epidermal lipid staining by Oil Red O and TLR3-dependent increases in lamellar bodies and keratohyalin granules. These observations show that dsRNA can stimulate some events in keratinocytes that are important for skin barrier repair and maintenance.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • ATP-Binding Cassette Transporters / genetics
  • ATP-Binding Cassette Transporters / metabolism
  • Cells, Cultured
  • Epidermal Cells
  • Epidermis / injuries
  • Epidermis / physiology*
  • Gene Expression / physiology
  • Humans
  • Keratinocytes / cytology
  • Keratinocytes / physiology*
  • Lipid Metabolism / physiology*
  • Organelles / metabolism*
  • Poly I-C / pharmacology
  • RNA, Double-Stranded / pharmacology
  • RNA, Messenger / metabolism
  • Toll-Like Receptor 3 / genetics*
  • Toll-Like Receptor 3 / metabolism
  • Transcriptome
  • Wound Healing / physiology*

Substances

  • ABCA12 protein, human
  • ATP-Binding Cassette Transporters
  • RNA, Double-Stranded
  • RNA, Messenger
  • TLR3 protein, human
  • Toll-Like Receptor 3
  • Poly I-C