Strong correlations exist between intra-uterine and/or fetal inflammation, prematurity and incidence of adverse neonatal outcomes, including cerebral palsy. If targeted interventions to improve outcome are to be developed we need to fully understand the molecular mechanisms which inadvertently cause fetal cell damage and tissue injury. Damage-associated molecular pattern molecules (DAMPs) are a pleiotropic group of intra-cellular proteins including high-mobility group box 1 protein (HMGB1) and members of the S100 calcium binding protein family (i.e., S100 A12, S100A8, S100B). When released into the extra-cellular compartment as a result of inflammation or oxidative stress, DAMPs become """"""""danger signals"""""""" by activating endogenous receptors such as the receptor of advanced glycation end-products (RAGE). Engagement of RAGE leads to cellular dysfunction and injury driven by oxidative stress and sustained activity of nuclear factor-kappa B (NF?B). Using proteomics we discovered that S100A12 plays a key role in orchestrating the intra-amniotic inflammatory response to infection via RAGE activation. We have also shown that human fetuses with heightened inflammatory statuses have increased systemic levels of prototype DAMPs such as HMGB1 and S100B. In addition, in a mouse model of endotoxin induced fetal damage we demonstrated that maternal inflammation is associated with fetal oxidative stress and depletion of the intracellular antioxidant glutathione. In the same experimental model we further provided evidence that HMGB1 and RAGE and over-expressed in the liver and brain of the fetuses exposed to inflammation in utero. This body of knowledge, corroborated with the evidence that HMGB1 and S100 proteins are putative RAGE ligands, has led us to propose an active role for the DAMP- RAGE axis in inducing antenatal end-organ damage in the setting of intra-amniotic infection and prematurity. To test this hypothesis, three aims will be pursued: 1) Specific Aim 1 is geared to provide in vivo observational evidence that intra-uterine inflammation induces an imbalance in the redox homeostasis of the human fetus, causing release of DAMP proteins and antenatal fetal cellular damage via RAGE activation;2) In Specific Aim 2 we will explore, in vitro, the mechanism and functional role of prototypical DAMPs and RAGE signaling in inducing cellular injury in a relevant bioassay. We will test the efficacy of anti-HMGB1 and anti-RAGE blocking antibodies or potential therapeutic agents such as N-acetylcysteine and ethyl pyruvate to reverse the damaging effects of the DAMP-RAGE axis activation;3) In Specific Aim 3, by using unique genetically engineered RAGE deficient (RAGE-/-) and RAGE transgenic (RAGETg+) animals, we plan to provide insight into RAGE signaling as the common and obligatory pathway leading to fetal damage and explore the value of DAMP and RAGE antagonism as treatment strategies in vivo. By completing these aims we hope to provide novel insight into the processes leading to end-organ damage in premature infants and identify new classes of molecular targets that can modulate the inflammatory response of the fetus and improve outcomes.

Public Health Relevance

/ RELEVANCE FOR PUBLIC HEALTH Damage-associated molecular pattern molecules (DAMPs) and the receptor of advanced glycation end- products (RAGE) are endogenous mediators of cellular injury leading to irreversible tissue damage. We discovered that in pregnancies complicated by intra-amniotic infection, the heightened states of inflammation and oxidative stress have all the requisite attributes to trigger RAGE engagement in vital fetal organs that may explain the increased incidence of poor outcomes associated with prematurity. By using genetically engineered animal models, we aim to provide insight into the pathological consequences of fetal RAGE activation and the potential of RAGE targeted therapeutic interventions to lower the neonatal morbidity and mortality of premature infants.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD062007-03
Application #
8291113
Study Section
Special Emphasis Panel (ZRG1-EMNR-H (03))
Program Officer
Reddy, Uma M
Project Start
2010-09-30
Project End
2013-03-31
Budget Start
2012-06-01
Budget End
2013-03-31
Support Year
3
Fiscal Year
2012
Total Cost
$240,894
Indirect Cost
$95,777
Name
Yale University
Department
Obstetrics & Gynecology
Type
Schools of Medicine
DUNS #
043207562
City
New Haven
State
CT
Country
United States
Zip Code
06520
Millen, Katherine R; Buhimschi, Catalin S; Zhao, Guomao et al. (2018) Serum and Urine Thioflavin-T-Enhanced Fluorescence in Severe Preeclampsia. Hypertension 71:1185-1192
McCarthy, Megan E; Buhimschi, Catalin S; Hardy, John T et al. (2018) Identification of haptoglobin switch-on status in archived placental specimens indicates antenatal exposure to inflammation and potential participation of the fetus in triggering preterm birth. Placenta 62:50-57
Shook, Lydia L; Buhimschi, Catalin S; Dulay, Antonette T et al. (2016) Calciprotein particles as potential etiologic agents of idiopathic preterm birth. Sci Transl Med 8:364ra154
Rood, Kara M; Buhimschi, Irina A; Rodewald Millen, Katherine et al. (2016) Evidence for participation of neutrophil gelatinase-associated lipocalin/matrix metalloproteinase-9 (NGAL•MMP-9) complex in the inflammatory response to infection in pregnancies complicated by preterm birth. Am J Reprod Immunol 76:108-17
Baumbusch, Margaret A; Buhimschi, Catalin S; Oliver, Emily A et al. (2016) High Mobility Group-Box 1 (HMGB1) levels are increased in amniotic fluid of women with intra-amniotic inflammation-determined preterm birth, and the source may be the damaged fetal membranes. Cytokine 81:82-7
Li, Qi; Tsuneki, Masayuki; Krauthammer, Michael et al. (2015) Modulation of Sox10, HIF-1?, Survivin, and YAP by Minocycline in the Treatment of Neurodevelopmental Handicaps following Hypoxic Insult. Am J Pathol 185:2364-78
Dulay, Antonette T; Buhimschi, Catalin S; Zhao, Guomao et al. (2015) Amniotic Fluid Soluble Myeloid Differentiation-2 (sMD-2) as Regulator of Intra-amniotic Inflammation in Infection-induced Preterm Birth. Am J Reprod Immunol 73:507-21
Dulay, Antonette T; Buhimschi, Irina A; Zhao, Guomao et al. (2015) Compartmentalization of acute phase reactants Interleukin-6, C-Reactive Protein and Procalcitonin as biomarkers of intra-amniotic infection and chorioamnionitis. Cytokine 76:236-243
Papanna, R; Block-Abraham, D; Mann, L K et al. (2014) Risk factors associated with preterm delivery after fetoscopic laser ablation for twin-twin transfusion syndrome. Ultrasound Obstet Gynecol 43:48-53
Wang, Xiaowei; Buhimschi, Catalin S; Temoin, Stephanie et al. (2013) Comparative microbial analysis of paired amniotic fluid and cord blood from pregnancies complicated by preterm birth and early-onset neonatal sepsis. PLoS One 8:e56131

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