Necrotizing enterocolitis (NEC) is a major concern in the neonatal intensive care unit, causing great morbidity and mortality. My long-term career goal is to elucidate the molecular mechanisms that lead to the development of NEC in the premature newborn infant. This will lead to the prevention and treatment of this devastating disease. My short-term goals are to gain knowledge and novel technical skills (such as in vivo gene transfer and laser-capture microdissection) that will enable me to make significant contributions in the field of NEC research and to become an independent research scientist. This award would allow the necessary support to achieve these goals, under the mentorship of Dr. Michael Caplan and Dr. Terrence Barrett in an excellent research environment. We have preliminary evidence that the transcription factor nuclear factor- (NF-kB) is developmentally regulated in the intestine and is persistently activated in a neonatal rat model of NEC. My overall hypothesis is that NEC results from the prolonged activation of NF- kB in the premature intestine in response to bacterial products and locally produced inflammatory lipid mediators such as platelet-activating factor (PAF), causing neutrophil infiltration and necrosis. In the premature infant, this persistent NF-kB activation leads to the upregulation of pro-inflammatory cytokines (e.g. TNF), chemokines (e.g. MIP-2) and adhesion molecules (e.g. ICAM-1) which amplify the inflammatory response. As a result, neutrophils are mobilized and activated, causing irreversible tissue injury and necrosis. The following specific aims will be addressed: 1) to characterize NF-kB activation in the neonatal model of NEC induced by hypoxia-cold stress-formula feeding; 2) to study the role of NF-kB in the neonatal NEC model and its mechanisms of action in a model of acute bowel injury; 3) to examine the effect of modulating the intestinal flora and treatment with probiotics on intestinal NF-KB activation in the neonatal NEC model. To do so, several transgenic mice models are proposed: mice lacking or over-expressing a specific subunit of NF-kB, reporter mice expressing NF-kB-dependent luciferase and finally in vivo gene transfer will be used. Understanding the developmental differences in the NF-kB activating pathway might lead to specific strategies geared at inhibiting NF-kB activation in the early stages of necrotizingenterocolitis. This could prevent its progression toward irreversible intestinal damage and improve the survival of premature infants. ? ?

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08HD044558-04
Application #
7236678
Study Section
Pediatrics Subcommittee (CHHD)
Program Officer
Nicholson, Carol E
Project Start
2004-07-01
Project End
2009-06-30
Budget Start
2007-07-01
Budget End
2008-06-30
Support Year
4
Fiscal Year
2007
Total Cost
$129,060
Indirect Cost
Name
Children's Memorial Hospital (Chicago)
Department
Type
DUNS #
074438755
City
Chicago
State
IL
Country
United States
Zip Code
60611
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Tian, Runlan; Liu, Shirley Xl; Williams, Cara et al. (2010) Characterization of a necrotizing enterocolitis model in newborn mice. Int J Clin Exp Med 3:293-302
Wang, Xiao; Bu, Heng-Fu; De Plaen, Isabelle G et al. (2009) Milk fat globule-EGF factor 8 mRNA expression in rat splanchnic tissues during postnatal development. Int J Clin Exp Med 2:36-40
Liu, Shirley X L; Tian, Runlan; Baskind, Heather et al. (2009) Platelet-activating factor induces the processing of nuclear factor-kappaB p105 into p50, which mediates acute bowel injury in mice. Am J Physiol Gastrointest Liver Physiol 297:G76-81
De Plaen, Isabelle G; Liu, Shirley X L; Tian, Runlan et al. (2007) Inhibition of nuclear factor-kappaB ameliorates bowel injury and prolongs survival in a neonatal rat model of necrotizing enterocolitis. Pediatr Res 61:716-21
De Plaen, Isabelle G; Han, Xin-Bing; Liu, Xueli et al. (2006) Lipopolysaccharide induces CXCL2/macrophage inflammatory protein-2 gene expression in enterocytes via NF-kappaB activation: independence from endogenous TNF-alpha and platelet-activating factor. Immunology 118:153-63