Intestinal barrier failure during experimental necrotizing enterocolitis: protective effect of EGF treatment.
Necrotizing enterocolitis (NEC) is the most common intestinal disease of premature infants. Although increased mucosal permeability and altered epithelial structure have been associated with many intestinal disorders, the role of intestinal barrier function in NEC pathogenesis is currently unknown. We investigated the structural and functional changes of the intestinal barrier in a rat model of NEC. In addition, the effect of EGF treatment on intestinal barrier function was evaluated. Premature rats were divided into three groups: dam fed (DF), formula fed (NEC), or fed with formula supplemented with 500 ng/ml EGF (NEC + EGF); all groups were exposed to asphyxia/cold stress to develop NEC. Intestinal permeability, goblet cell density, mucin production, and composition of tight junction (TJ) proteins were evaluated in the terminal ileum, the site of NEC injury, and compared with the proximal jejunum, which was unaffected by NEC. Animals with NEC had significantly increased intestinal paracellular permeability compared with DF pups. Ileal goblet cell morphology, mucin production, and TJ composition were altered in animals with NEC. EGF treatment significantly decreased intestinal paracellular permeability, increased goblet cell density and mucin production, and normalized expression of two major TJ proteins, occludin and claudin-3, in the ileum. In conclusion, experimental NEC is associated with disruption of the intestinal barrier. EGF treatment maintains intestinal integrity at the site of injury by accelerating goblet cell maturation and mucin production and normalizing expression of TJ proteins, leading to improved intestinal barrier function.
Clark
Jessica A
JA
Department of Pediatrics, University of Arizona, Tucson, AZ 85724-5073, USA.
Doelle
Sarah M
SM
Halpern
Melissa D
MD
Saunders
Tara A
TA
Holubec
Hana
H
Dvorak
Katerina
K
Boitano
Scott A
SA
Dvorak
Bohuslav
B
D000818:Animals; D000831:Animals, Newborn; D015153:Blotting, Western; D002452:Cell Count; D062465:Claudin-3; D020345:Enterocolitis, Necrotizing / Q000473:pathology* / Q000517:prevention & control*; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005455:Fluorescent Antibody Technique; D020397:Goblet Cells / Q000502:physiology; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D008565:Membrane Proteins / Q000096:biosynthesis / Q000502:physiology; D008855:Microscopy, Electron, Scanning; D055262:Mucin-2; D009077:Mucins / Q000096:biosynthesis / Q000235:genetics; D062793:Occludin; D010539:Permeability / Q000187:drug effects; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015996:Survival Rate
D062465:Claudin-3; C568124:Cldn3 protein, rat; D008565:Membrane Proteins; C524628:Muc2 protein, rat; D055262:Mucin-2; D009077:Mucins; D062793:Occludin; C568987:Ocln protein, rat; D004815:Epidermal Growth Factor; D012313:RNA