051 - Extracellular NAMPT: A Novel Therapeutic Target in intra-amniotic inflammation (IAI) using large animal model

Publication Number: 51.4671

Mohamed Ahmed, Florida State University College of Medicine, Gainesville, FL, United States; Gupta Akash, University of Arizona, Tucson, AZ, United States; Nahla Zaghloul, University of Florida, gainesville, FL, United States; Senthilkumar Thulasingam, University Arizona College of Medicine, Tucson, AZ, United States; Sean W.. Limesand, University Arizona College of Medicine, Tucson, AZ, United States; Joe GN Garcia, University of Florida College of Medicine, Jupiter, FL, United States

Background: There is a desperate need to identify novel therapies to reduce perinatal mortality and long-term morbidity of chorioamnionitis-related prematurity. It was showed that chorio human placentas displayed a significant increase in eNAMPT expression compared to non-chorio ones. eNAMPT has a significant role in innate immunity as a proinflammatory cytokine that increases inflammatory cell survival and inflammatory cytokine production via ligation of TLR4 and NF-kB activation. eNAMPT neutralizing mAb (ALT-100 mAB), markedly reduces eNAMPT/TLR4-mediated innate immunity activation, NFkB transcriptional activities, and inflammation in humans with acute inflammatory lung injury (ARDS). Prelim data using murine animal model with chorio, showed that treated group had a significant improve of survival rates, and less postnatal morbidity compared to non-treated dams.

Objective: Study the impact of eNAMPT mAb treatment on systemic inflammatory response in maternal & fetal sheep with intra-amniotic inflammation (IAI)

Design/Methods: At ~117 dGA, twelve pregnant ewes and fetuses were surgically instrumented with indwelling IV and amniotic catheters for sampling/infusions. At ~120 dGA, a series of IV boluses were administered to the fetuses: LPS boluses; E.coli O55:B5; (n=10 fetuses) or saline boluses (control) (n=2 fetuses). LPS doses (0.3ug, 1.5ug, 3ug, 15ug) were given on d120, 122, 123, and 124 of GA, respectively. 5/10 LPS-exposed pregnant sheep were treated with a single IV dose of ALT-100 mAb (0.4 or 1mg/kg) on d121. All fetuses were delivered by C-section on 125 dGA.

Results: Fetuses receiving LPS demonstrated significant reductions in fetal blood pH and PaO2, and increased plasma lactate and cortisol level, in comparison to treated group with ALT-100 mAb. Leukocytosis were significantly reduced in ALT-100 mAb-treated fetal sheep. Western blot of inflammatory cytokines showed significant increase of many cytokines in fetal organs (lung, heart, brain and placenta) among chorio group compared to chorio group treated with ALT-100 mAb. Transcriptome studies showed that PCA of three studied groups, demonstrated expected grouping and sample groups spread across the three PCs. Differential gene expressions (DGEs) illustrated 1126 genes of which 312 genes are upregulated and 814 genes are down regulated, with a significant downregulation of TNF1 signaling via NFkb, hedgehog signaling, E2F target signaling, and gene network involved in oxidative phosphorylation.

Conclusion(s): eNAMPT/TLR4 inflammatory pathway is a highly druggable and novel therapeutic target to reduce severity of IAI and improve neonatal outcomes.