MyD88 signaling in nonhematopoietic cells protects mice against induced colitis by regulating specific EGF receptor ligands

Proc Natl Acad Sci U S A. 2010 Nov 16;107(46):19967-72. doi: 10.1073/pnas.1014669107. Epub 2010 Nov 1.

Abstract

Toll-like receptors (TLRs) trigger intestinal inflammation when the epithelial barrier is breached by physical trauma or pathogenic microbes. Although it has been shown that TLR-mediated signals are ultimately protective in models of acute intestinal inflammation [such as dextran sulfate sodium (DSS)-induced colitis], it is less clear which cells mediate protection. Here we demonstrate that TLR signaling in the nonhematopoietic compartment confers protection in acute DSS-induced colitis. Epithelial cells of MyD88/Trif-deficient mice express diminished levels of the epidermal growth factor receptor (EGFR) ligands amphiregulin (AREG) and epiregulin (EREG), and systemic lipopolysaccharide administration induces their expression in the colon. N-ethyl-N-nitrosourea (ENU)-induced mutations in Adam17 (which is required for AREG and EREG processing) and in Egfr both produce a strong DSS colitis phenotype, and the Adam17 mutation exerts its deleterious effect in the nonhematopoietic compartment. The effect of abrogation of TLR signaling is mitigated by systemic administration of AREG. A TLR→MyD88→AREG/EREG→EGFR signaling pathway is represented in nonhematopoietic cells of the intestinal tract, responds to microbial stimuli once barriers are breached, and mediates protection against DSS-induced colitis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Vesicular Transport / deficiency
  • Amphiregulin
  • Animals
  • Colitis / chemically induced
  • Colitis / metabolism
  • Colitis / prevention & control*
  • Dextran Sulfate
  • EGF Family of Proteins
  • Epidermal Growth Factor / metabolism*
  • Epiregulin
  • ErbB Receptors / metabolism*
  • Glycoproteins / metabolism*
  • Hematopoietic System / cytology*
  • Intercellular Signaling Peptides and Proteins / metabolism*
  • Ligands
  • Lipopolysaccharides / pharmacology
  • Metagenome / drug effects
  • Mice
  • Mice, Inbred C57BL
  • Mutation / genetics
  • Myeloid Differentiation Factor 88 / deficiency
  • Myeloid Differentiation Factor 88 / metabolism*
  • Phenotype
  • Signal Transduction* / drug effects
  • Toll-Like Receptors / metabolism

Substances

  • Adaptor Proteins, Vesicular Transport
  • Amphiregulin
  • Areg protein, mouse
  • EGF Family of Proteins
  • Epiregulin
  • Ereg protein, mouse
  • Glycoproteins
  • Intercellular Signaling Peptides and Proteins
  • Ligands
  • Lipopolysaccharides
  • Myeloid Differentiation Factor 88
  • TICAM-1 protein, mouse
  • Toll-Like Receptors
  • Epidermal Growth Factor
  • Dextran Sulfate
  • ErbB Receptors