An immunoprotective privilege of corneal epithelial stem cells against Th17 inflammatory stress by producing glial cell-derived neurotrophic factor

Fang Bian, Hong Qi, Ping Ma, Lili Zhang, Kyung-Chul Yoon, Stephen C Pflugfelder, De-Quan Li

Research output: Contribution to journalArticlepeer-review

29 Scopus citations

Abstract

Adult stem cells are well known for their self-renewal and regenerative capacity. The mechanisms protecting these cells from inflammatory damage have not been well elucidated. This study investigated the immunoprotective properties of corneal epithelial stem cells from inflammation by producing glial cell-derived neurotrophic factor (GDNF). Primary human limbal epithelial cells (HLECs) cultured from limbal explants were treated with interleukin (IL)-17A, tumor necrosis factor (TNF)-α, or hyperosmotic media, with or without GDNF or nuclear factor kappa B (NF-κB) inhibitor (NF-κB-I) for 4-48 hours. Inflammatory mediators and Th17-inducing cytokines were determined by real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and immunobead assays. NF-κB activation was detected by p65 phosphorylation, immunostaining and Western blotting. GDNF and its receptor, GDNF family receptor α-1, were exclusively immunolocalized in the basal layer of limbal epithelium, whereas IL-17 receptor was negative in these cells. Exogenous IL-17A stimulated the expression and production of inflammatory cytokines (TNF-α, IL-6, and IL-1β) and chemokine IL-8 by HLECs. Th17-inducing cytokines, transforming growth factor (TGF)-β1, IL-6, IL-23, and IL-1β, were significantly increased at mRNA and protein levels by HLECs exposed to TNF-α or hyperosmotic media. IL-17 activated NF-κB by p65 phosphorylation at serine 536 and nuclear translocation. GDNF or NF-κB-I blocked IL-17-induced NF-κB p65 activation and production of inflammatory mediators. Furthermore, GDNF suppressed the production of Th17-inducing cytokines through inhibiting NF-κB activation. These findings demonstrate that limbal progenitor cell-produced neurotrophic factor GDNF suppresses IL-17-mediated inflammation via NF-κB signaling pathway. This may represent a unique immunoprotective property of limbal stem cells against inflammatory challenges on the ocular surface.

Original languageEnglish (US)
Pages (from-to)2172-81
Number of pages10
JournalStem cells (Dayton, Ohio)
Volume28
Issue number12
DOIs
StatePublished - Dec 2010

Keywords

  • Adolescent
  • Adult
  • Animals
  • Cytoprotection/drug effects
  • Epithelial Cells/cytology
  • Epithelium, Corneal/cytology
  • Glial Cell Line-Derived Neurotrophic Factor/biosynthesis
  • Glial Cell Line-Derived Neurotrophic Factor Receptors/metabolism
  • Humans
  • Inflammation/pathology
  • Interleukin-17/pharmacology
  • Mice
  • Middle Aged
  • NF-kappa B/metabolism
  • Osmotic Pressure/drug effects
  • Protein Transport/drug effects
  • Receptors, Interleukin-17/metabolism
  • Signal Transduction/drug effects
  • Stem Cells/cytology
  • Stress, Physiological/drug effects
  • Th17 Cells/drug effects
  • Tumor Necrosis Factor-alpha/pharmacology
  • Young Adult

Fingerprint

Dive into the research topics of 'An immunoprotective privilege of corneal epithelial stem cells against Th17 inflammatory stress by producing glial cell-derived neurotrophic factor'. Together they form a unique fingerprint.

Cite this