Glial cell line-derived neurotrophic factor promotes barrier maturation and wound healing in intestinal epithelial cells in vitro

Am J Physiol Gastrointest Liver Physiol. 2015 Oct 15;309(8):G613-24. doi: 10.1152/ajpgi.00357.2014. Epub 2015 Aug 20.


Recent data suggest that neurotrophic factors from the enteric nervous system are involved in intestinal epithelial barrier regulation. In this context the glial cell line-derived neurotrophic factor (GDNF) was shown to affect gut barrier properties in vivo directly or indirectly by largely undefined processes in a model of inflammatory bowel disease (IBD). We further investigated the potential role and mechanisms of GDNF in the regulation of intestinal barrier functions. Immunostaining of human gut specimen showed positive GDNF staining in enteric neuronal plexus and in enterocytes. In Western blots of the intestinal epithelial cell lines Caco2 and HT29B6, significant amounts of GDNF were detected, suggesting that enterocytes represent an additional source of GDNF. Application of recombinant GDNF on Caco2 and HT29B6 cells for 24 h resulted in significant epithelial barrier stabilization in monolayers with immature barrier functions. Wound-healing assays showed a significantly faster closure of the wounded areas after GDNF application. GDNF augmented cAMP levels and led to significant inactivation of p38 MAPK in immature cells. Activation of p38 MAPK signaling by SB-202190 mimicked GDNF-induced barrier maturation, whereas the p38 MAPK activator anisomycin blocked GDNF-induced effects. Increasing cAMP levels had adverse effects on barrier maturation, as revealed by permeability measurements. However, increased cAMP augmented the proliferation rate in Caco2 cells, and GDNF-induced proliferation of epithelial cells was abrogated by the PKA inhibitor H89. Our data show that enterocytes represent an additional source of GDNF synthesis. GDNF contributes to wound healing in a cAMP/PKA-dependent manner and promotes barrier maturation in immature enterocytes cells by inactivation of p38 MAPK signaling.

Keywords: GDNF; barrier maturation; intestinal barrier; p38 MAPK; wound healing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Caco-2 Cells
  • Cyclic AMP / metabolism
  • Cyclic AMP-Dependent Protein Kinases / metabolism
  • Enterocytes / metabolism
  • Epithelial Cells / drug effects*
  • Gene Expression Regulation / physiology
  • Glial Cell Line-Derived Neurotrophic Factor / pharmacology*
  • Glial Cell Line-Derived Neurotrophic Factor Receptors / genetics
  • Glial Cell Line-Derived Neurotrophic Factor Receptors / metabolism
  • HT29 Cells
  • Humans
  • Intestinal Mucosa / cytology*
  • Signal Transduction / drug effects
  • Signal Transduction / physiology
  • Wound Healing / drug effects*
  • Wound Healing / physiology
  • p38 Mitogen-Activated Protein Kinases / genetics
  • p38 Mitogen-Activated Protein Kinases / metabolism


  • Glial Cell Line-Derived Neurotrophic Factor
  • Glial Cell Line-Derived Neurotrophic Factor Receptors
  • Cyclic AMP
  • Cyclic AMP-Dependent Protein Kinases
  • p38 Mitogen-Activated Protein Kinases