Distribution of enteric glia and GDNF during gut inflammation

Abstract

BackgroundThe enteric glia network may be involved in the pathogenesis of inflammatory bowel disease (IBD). Enteric glia cells (EGCs) are the major source of glial-derived neurotrophic factor (GDNF), which regulates apoptosis of enterocytes. The aim of the study was to determine the distribution of EGCs and GDNF during gut inflammation and to elucidate a possible diminished enteric glia network in IBD.MethodsThe expression of glial fibrillary acidic protein (GFAP) in colonic biopsies of patients with IBD, controls and patients with infectious colitis was detected by immunohistochemistry and Western blot. Tissue GDNF levels were measured by ELISA.ResultsThe expression of GFAP and GDNF in the mucosal plexus is highly increased in the inflamed colon of patients with ulcerative colitis (UC) and infectious colitis. Although the GDNF and GFAP content are increased in Crohn's disease (CD), it is significantly less. Additionally the non-inflamed colon of CD patients showed a reduced GFAP and no GDNF expression compared to controls and the non-inflamed colon of UC patients.ConclusionsGFAP and GDNF as signs of activated EGCs are increased in the inflamed mucosa of patients with UC and infectious colitis, which underline an unspecific role of EGC in the regulation of intestinal inflammation. The reduced GFAP and GDNF content in the colon of CD patients suggest a diminished EGC network in this disease. This might be a part of the pathophysiological puzzle of CD.

The glial cell-line derived neurotrophic factor: a novel regulator of intestinal barrier function in health and disease

“…Additionally, a coculture of EGC with intestinal epithelial cells increased IEB function (45). Furthermore, there is a reduced distribution of enteric glial cells in uninflamed colon segments of patients suffering from IBD compared with control popula-tions, suggesting that enteric glial cells could play a role in the pathogenesis of intestinal barrier defects in CD or UC (60). All these observations suggest a close interaction between EGCs and enterocytes.…”

Enteric Glial Cells: Recent Developments and Future Directions

“…29 von Boyen et al consistently reported a less prominent increase of GFAP (and GDNF) in patients with CD compared with UC. 57 It is tentative to speculate that an altered glial reactivity (as possibly observed in CD) or excessive gliosis (as possibly observed in UC) could contribute to different pathological conditions.…”

Novel functional roles for enteric glia in the gastrointestinal tract

“…24 Reactive enteric glia, as with reactive astrocytes, display a marked hypertrophy, 25 increased proliferation 26,27 and vary expression of both cytoplasmic 23 and surface proteins 28 under certain conditions. Notably, under pathological conditions, enteric glia can transform into antigen-presenting cells that promote inflammation by attracting immune cells.…”