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Disruption of Tight Junction Barrier Function and Upregulation of Inflammatory Signaling Pathway in a Necrotizing Enterocolitis Mouse Model
Author(s) -
Ravisankar Srikanth,
Tatum Rodney,
Herco Maja,
Chen YanHua
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.265.5
Subject(s) - tight junction , claudin , necrotizing enterocolitis , barrier function , western blot , downregulation and upregulation , medicine , immunostaining , enterocolitis , biology , andrology , immunohistochemistry , chemistry , microbiology and biotechnology , biochemistry , gene
Necrotizing enterocolitis (NEC) is a leading cause of death in preterm infants. Neonates weighing <1500 grams are at highest risk for the disease, with a prevalence of 7% and mortality up to 30%. Despite advancements in neonatal medicine, this disease remains a challenge. To study the molecular mechanism underlying NEC, we produced a mouse NEC model to examine the tight junction integrity and epithelial barrier function in NEC intestines. Three‐day old C57BL/6 mouse pups were fed with 50 µl of 33% Esbilac formula every 3 hours and then asphyxiated twice daily (100% N 2 for 60 sec) followed by cold stress at 4°C for 10 minutes. Dam fed pups from the same litter served as controls. Pups were sacrificed 96 hours later. Successful induction of NEC was confirmed by histopathology. Western blot analysis revealed the increased expression levels of tight junction protein claudin‐2 and ‐7, while claudin‐3 expression level was decreased in the NEC intestines compared to those of controls. In addition, NF‐kB and TGFβ expression levels were also upregulated, suggesting the activation of the inflammatory signaling pathway in the NEC intestines. More importantly, we found that the tight junction in NEC intestines was leaky since the biotin tracer molecules were diffused from lumen into the tissue through the intercellular space. We conclude that there is a loss of tight junction barrier function and alteration of tight junction claudin proteins in the intestines of NEC mouse model. This work is supported by a research fund from Department of Pediatrics, BSOM at ECU and National Institute of Health grant HL085752.