335 - Integrating metabolomics and Oxidized lipomics Reveals glycerophospholipid- arachidonic acid metabolism mechanism in NEC

Poster Number: 335
Publication Number: 335.133

QinLei Yu, Women's Hospital of Nanjing medical University, nanjing, Jiangsu, China (People's Republic); shuwen Yao, The Women's Hospital of Nanjing Medical University, nanjing, Jiangsu, China (People's Republic); xiangyun yan, Women’s Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital,, Nanjing, Jiangsu, China (People's Republic); shuping han, Women’s Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital,, nanjing, Jiangsu, China (People's Republic)

Background: Necrotizing enterocolitis (NEC) is one of the most common intestinal acute inflammatory disease in neonates, especially in preterm infants. Glycerophospholipid-arachidonic acid metabolic mechanism has been found to have a possible mitigating effect in NEC.

Objective: Possible biomarkers were screened by metabonomics and lipoomics as potential targets for NEC treatment.

Design/Methods:

1. The neonatal rat model of NEC was established by giving formula milk gavage, cold stimulation and hypoxia daily, beginning on day 1 for 4 days. On the last day, feces were collected before execution, and terminal ileum was harvested and divided into two parts to verify the model and carry out  subsequent experiments.

2. Liquid chromatography/tandem mass spectrometry (LC-MS)  metabolomics were used to detect fecal metabolic profiles between the control group and the model group. Oxidized lipid metabolomics were used to analyze the changes of oxidized lipids, downstream of oxidative stress. Malondialdehyde (MDA) and superoxide dismutase (SOD) were used to verify the changes of oxidative stress level in intestinal tissue.

3. We detected the changes of ferroptosis marker proteins in intestinal tissues by Immunohistochemistry, and use Iron Assay Kit to quantify iron ions. Further more, transmission electron microscopy was used to observe the changes in intestinal mitochondria.

Results:

1. The treated rats showed significant weight loss, increased mortality, severe villus damage, and pathological score of intestinal tissue indicating that the NEC model was reliable.

2. Metabolomics demonstrated that there were significant differences in glycerophospholipid-arachidonic acid metabolism mechanism between the two groups. Oxidized lipomics indicated the changes of oxidized lipids downstream of arachidonic acid, and some specific oxidized lipids were closely related to ferroptosis.

3. The increase of ferroptosis was verified by immunohistochemistry through GPX4 and ACSL4. Under the transmission electron microscope, the mitochondria showed obvious changes: smaller size,  reduced or disappeared ridge, outer membrane rupture, which were characteristic changes of ferroptosis. SOD decreased and MDA increased in NEC group compared with that in control group, which indicating the existence of severe oxidative stress.

Conclusion(s): These results demonstrate that glycerophospholipid-arachidonic acid metabolism mechanism may play an important role in alleviating NEC,  in which ferroptosis may be a key signaling pathway, and relevant biomarkers are expected to become therapeutic targets for NEC.