Abstract
Neonatal necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease of preterm infants. Increased intestinal epithelium permeability is an early event in NEC pathogenesis. Autophagy and apoptosis are induced by multiple stress pathways which may impact the intestinal barrier, and they have been associated with pathogenesis of diverse gastrointestinal diseases including inflammatory bowel disease. Using both in vitro and in vivo models, this study investigates autophagy and apoptosis under experimental NEC stresses. Furthermore this study evaluates the effect of erythropoietin (Epo), a component of breast milk previously shown to decrease the incidence of NEC and to preserve intestinal barrier function, on intestinal autophagy and apoptosis. It was found that autophagy and apoptosis are both rapidly up regulated in NEC in vivo as indicated by increased expression of the autophagy markers Beclin 1 and LC3II, and by evidence of apoptosis by TUNEL and cleaved caspase-3 staining. In the rat NEC experimental model, autophagy preceded the onset of apoptosis in intestine. In vitro studies suggested that Epo supplementation significantly decreased both autophagy and apoptosis via the Akt/mTOR signaling pathway and the MAPK/ERK pathway respectively. These results suggest that Epo protects intestinal epithelium from excessive autophagy and apoptosis in experimental NEC.
Publication types
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Research Support, N.I.H., Extramural
MeSH terms
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Animals
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Animals, Newborn
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Apoptosis Regulatory Proteins / genetics
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Apoptosis Regulatory Proteins / metabolism
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Apoptosis*
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Autophagy*
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Beclin-1
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Caspase 3 / genetics
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Caspase 3 / metabolism
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Disease Models, Animal
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Enterocolitis, Necrotizing / genetics
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Enterocolitis, Necrotizing / metabolism
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Enterocolitis, Necrotizing / pathology
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Enterocolitis, Necrotizing / prevention & control*
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Epithelial Cells / drug effects*
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Epithelial Cells / metabolism
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Epithelial Cells / pathology
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Erythropoietin / genetics
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Erythropoietin / metabolism
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Erythropoietin / pharmacology*
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Extracellular Signal-Regulated MAP Kinases / genetics
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Extracellular Signal-Regulated MAP Kinases / metabolism
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Gene Expression
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Humans
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Infant, Newborn
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Intestinal Mucosa / drug effects*
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Intestinal Mucosa / metabolism
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Intestinal Mucosa / pathology
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Intestines / drug effects*
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Intestines / pathology
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Membrane Proteins / genetics
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Membrane Proteins / metabolism
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Microtubule-Associated Proteins / genetics
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Microtubule-Associated Proteins / metabolism
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Milk, Human / chemistry
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Proto-Oncogene Proteins c-akt / genetics
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Proto-Oncogene Proteins c-akt / metabolism
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Rats
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Signal Transduction
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TOR Serine-Threonine Kinases / genetics
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TOR Serine-Threonine Kinases / metabolism
Substances
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Apoptosis Regulatory Proteins
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BECN1 protein, human
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Beclin-1
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EPO protein, human
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MAP1LC3A protein, human
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Membrane Proteins
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Microtubule-Associated Proteins
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Erythropoietin
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MTOR protein, human
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Proto-Oncogene Proteins c-akt
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TOR Serine-Threonine Kinases
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Extracellular Signal-Regulated MAP Kinases
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Caspase 3