N. Denning1,3,4, W. Yang1,3,4, L. Hansen3, J. M. Prince1,2,3, P. Wang1,3,4 1The Feinstein Institute for Medical Research at Northwell Health,Center For Immunology And Inflammation,Manhasset, NY, USA 2Cohen Children’s Medical Center at Northwell Health,Division of Pediatric Surgery,New Hyde Park, NY, USA 3Zucker School of Medicine at Hofstra/Northwell,Department Of Surgery,Manhasset, NY, USA 4Feinstein Institute for Medical Research,Elmezzi School Of Molecular Medicine,Manhasset, NY, USA
Introduction: Neonatal sepsis remains a leading cause of infant mortality. Cold inducible RNA binding protein (CIRP) is an inflammatory mediator that induces TNF-α production in macrophages. C23 is a CIRP-derived oligopeptide that can prevent CIRP from binding to its receptor. We hypothesized that treatment with C23 would reduce systemic inflammation and protect the lungs in neonatal sepsis.
Methods: Sepsis was induced in C56BL/6 mouse pups (5-7 days) by intraperitoneal injection of adult cecal slurry (.525 mg/g body weight, LD100). One hour later pups received retro-orbital injection of C23 (8 mg/kg) or equivalent volume of vehicle (0.9% NS). Ten hours after sepsis induction blood and tissues were collected for analysis.
Results: C23 treatment resulted in a 58% and 69% reduction in serum levels of pro-inflammatory cytokines IL-6 and IL-1β , respectively. C23 reduced markers of organ injury. AST was reduced by 40% in C23-treated pups compared to vehicle-treated septic pups, from 168.30 ± 21.08 to 99.89 ± 40.07 (p<0.05). LDH was decreased by 45%, from 168.3 ± 46.76 in vehicle animals to 92.12 ± 56.52 in C23-treated mice (p<0.05). In the lungs, C23 treatment reduced expression of cytokines IL-6 and IL-1β by 78% and 74%. In addition, the mRNA level of neutrophil chemoattractant KC was reduced by 84%. (Table). These results corresponded to a reduction in histologic lung injury score. Vehicle- treated pups scored 0.49 ± 0.19, while C23 treatment reduced scores to 0.29 ± 0.12 (p<0.05; Max = 1). Apoptosis in the lungs, measured by TUNEL assay, was also decreased by 53% with C23 treatment (p<0.05).
Conclusion: Inhibition of CIRP with C23 treatment is protective in septic neonatal mice as demonstrated by reduced inflammatory markers systemically and in the lung. Therefore, C23 has promising therapeutic potential in treatment of neonatal sepsis.
