508 - Modified human milk derived peptide in the protection against experimental Necrotizing Enterocolitis.

Poster Number: 508
Publication Number: 508.426

Xiangyun Yan, Nanjing Maternity and Child Health Care Hospital, NanJing, Jiangsu, China (People's Republic); shuping Han, Maternity Hospital Affiliated to Nanjing Medical University, Nanjing, Jiangsu, China (People's Republic)

Background: Necrotizing enterocolitis (NEC) is the common gastrointestinal emergency in preterm infants. It has been long recognized that breast milk is an effective strategy to reduce the incidence of NEC. Recently, the multifunctional peptides in breast milk are increasingly acknowledged.

Objective: In this study, we found a milk derived bioactive peptide using mass spectrometry. Our preliminary studies indicate that this peptide exerts a potential role in NEC treatment.

Design/Methods: 1、 The peptide was modified with a transmembrane sequence, which was thought to enhance the capacity of transmembrane. FITC-conjugated natural milk derived peptides (NMdp) and modified milk derived peptides (MMdp) were prepared to detect the intracellular localization in rat small intestinal IEC-6 cells. 2、 LPS (100 ug/ml) was used in IEC-6 cells to establish the in vitro cell model for NEC. The expression levels of inflammatory cytokines were measured by Quantitative real-time PCR. 3、 The in vivo rat model of NEC was induced with formula gavage three times per day, as well as hypoxia for 5 min twice daily for 4 days. Immediately after killing, the terminal ileum was harvested and divided into two parts to assess the severity of disease and detect the inflammatory level.

Results: 1、 In the same treatment concentration and time, the co-incubation of FITC-MMdp with IEC-6 cells led to higher fluorescent intensity compared with the FITC-NMdp treated cells. 2、 Treatment of IEC-6 cells with LPS resulted in a significant increase in the mRNA expression levels of interleukin-6(IL-6) and cyclooxygenase-2 (COX-2). Strikingly, the extent of inflammatory cytokines were decreased significantly when cells were pretreated with MMdp 60 min before LPS treatment. 3、 The in vivo model of NEC is characterized with induction of IL-6 and COX-2 gene expressions and disruption of the ileal mucosa as compared with control mice. Importantly, the enteral application of MMdp effectively attenuated NEC severity, as manifested by a reduction in the expressions of inflammation indexes and preservation of mucosal architecture.Conclusion(s): The evolution of the MMdp improves the biological properties of transmembrane, which provides a new opportunity for the prevention and treatment of NEC. The administration of MMdp effectively inhibited the inflammation of in vitro or vivo NEC model. Additionally, the MMdp can repair intestinal mucosal injury to restrain the development of NEC.