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Updated: Jun 13, 2025
A Neonatal BALB/c Mouse Model of Necrotizing Enterocolitis
Published on: November 30, 2021
Silencing miR-155-5p expression improves intestinal damage through inhibiting inflammation and ferroptosis in
Le Zhang1,2, Weilai Jin2, Mengyuan Hu3
1Key Laboratory of Birth Defects, Children's Hospital, Institutes of Biomedical Sciences, Fudan University, Shanghai, China.
Insights
Reducing miR-155-5p expression alleviates intestinal damage in necrotizing enterocolitis (NEC) by inhibiting inflammation and ferroptosis. This offers potential new therapeutic strategies for NEC treatment.
Area of Science:
- Biomedical Science
- Molecular Biology
- Gastroenterology
Background:
- Necrotizing enterocolitis (NEC) is a severe intestinal condition primarily affecting premature infants.
- Increased miR-155-5p expression is observed in NEC intestinal tissues, but its role and mechanisms remain unclear.
Purpose of the Study:
- To investigate the role of miR-155-5p in NEC pathogenesis.
- To elucidate the underlying molecular mechanisms involving miR-155-5p in NEC.
Main Methods:
- Established in vitro (lipopolysaccharide-induced) and in vivo (hypoxia and formula feeding) NEC models.
- Assessed inflammatory cytokines, cell survival, apoptosis, oxidative stress markers (GSH, SOD, CAT, MDA), ROS, mitochondrial membrane potential, and ferroptosis-related proteins.
- Utilized Western blotting and hematoxylin and eosin staining for molecular and histopathological analysis.
Main Results:
- Inhibition of miR-155-5p improved cell survival, reduced apoptosis, inflammation, and ferroptosis in NEC models.
- miR-155-5p directly targets SLC7A11; its inhibition upregulated SLC7A11, mitigating LPS-induced inflammation and ferroptosis.
- Observed changes in ferroptosis markers (FTH1, GPX4, COX-2, ACSL4), oxidative stress markers, inflammatory cytokines (IL-6, TNF-α), and suppressed IκBα/NF-κB p65 signaling.
Conclusions:
- Reducing miR-155-5p expression ameliorates intestinal damage in NEC by suppressing inflammation and ferroptosis.
- Targeting miR-155-5p presents a promising therapeutic avenue for NEC, supported by mechanistic insights into SLC7A11 regulation.
Background:
Necrotizing enterocolitis (NEC) is a condition characterized by acquired damage to the mucosal lining, predominantly affecting premature infants. Bioinformatics assessments uncovered a notable rise in miR-155-5p expression in the intestinal tissues of infants suffering from NEC. Nevertheless, the development of NEC's underlying mechanisms and the role of miR-155-5p are still not well understood. This research aimed to explore the role of miR-155-5p in NEC and to elucidate its underlying mechanisms.
Methods:
To replicate NEC in vitro, lipopolysaccharide (LPS) was employed, whereas an in vivo rat model of NEC was established using formula feeding and exposure to hypoxia. Subsequently, levels of inflammatory cytokines, cell survival, and apoptosis rates were assessed. Various biochemical indicators such as glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) were measured utilizing a purchased diagnostic kit. For the assessment of reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) within FHC cells, analysis by flow cytometry was conducted. Additionally, the technique of Western blotting was utilized to analyze the levels of ferroptosis-associated proteins. Moreover, hematoxylin and eosin (H&E) staining was carried out to observe the histopathological alterations in the intestinal tissue samples from rats with necrotizing enterocolitis (NEC).
Results:
Reducing miR-155-5p improved the survival of FHC cells exposed to LPS, decreased cell apoptosis, inflammation, and ferroptosis, and mitigated intestinal damage in NEC rats. Furthermore, SLC7A11 was found to be a direct target of miR-155-5p. The inhibition of miR-155-5p decreased LPS-induced inflammation and ferroptosis in both FHC cells and NEC rats by promoting SLC7A11 expression. This effect was evidenced by increased levels of ferroptosis-related proteins FTH1 and GPX4, decreased COX-2 and ACSL4 levels, lower lipid peroxidation marker MDA, reduced antioxidant markers GSH, SOD, and CAT, fewer IL-6 and TNF-α, and suppression of the IκBα/NF-κB p65 signaling pathway.
Conclusions:
In conclusion, reducing miR-155-5p could improve intestinal damage in NEC by inhibiting inflammation and ferroptosis. These findings may provide theoretical insights for the development of new therapies for NEC.
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