TWEAK/Fn14 pathway promotes a T helper 2-type chronic colitis with fibrosis in mice

A Son1, T Oshio, Y I Kawamura

  • 1Department of Gastroenterology, Research Center for Hepatitis and Immunology, Research Institute, National Center for Global Health and Medicine, Chiba, Japan.

Mucosal Immunology
|March 7, 2013
PubMed

Insights

Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) signaling via Fn14 exacerbates chronic colitis and fibrosis. Blocking this pathway reduces inflammation and Th2 immunity, suggesting a therapeutic target for inflammatory bowel disease.

Area of Science:

  • Immunology
  • Gastroenterology
  • Cell Biology

Background:

  • Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) and its receptor Fn14 are implicated in epithelial cell damage and inflammation in acute colitis.
  • Chronic colitis models often involve complex immune responses and tissue remodeling, including fibrosis.

Purpose of the Study:

  • To investigate the role of the TWEAK/Fn14 axis in chronic colitis with fibrosis.
  • To elucidate the involvement of thymic stromal lymphopoietin (TSLP) and T helper 2 (Th2) immunity in this model.

Main Methods:

  • Induction of chronic colitis in wild-type (WT) and Fn14 gene knockout (KO) mice via rectal hapten injection.
  • Assessment of inflammation, fibrosis, Th2-type immunity, and gene/protein expression (TSLP, IL-13).
  • Functional studies using colon explants and TSLP receptor KO mice.

Main Results:

  • Fn14 KO mice exhibited significantly reduced inflammation, fibrosis, and Th2 immunity compared to WT mice.
  • TSLP expression was lower in Fn14 KO colon epithelial cells; TWEAK potentiated IL-13-induced TSLP production in WT but not Fn14 KO tissues.
  • TSLP receptor KO mice showed milder chronic colitis, and TWEAK/IL-13 synergistically promoted fibroblast proliferation.

Conclusions:

  • The IL-13-TWEAK/Fn14-TSLP axis is a critical mechanism driving chronic colitis with fibrosis.
  • Targeting this axis may offer a therapeutic strategy for inflammatory bowel disease characterized by fibrosis.