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Updated: Aug 3, 2026
A Novel Human Epithelial Enteroid Model of Necrotizing Enterocolitis
Published on: April 10, 2019
NLRP3 activation in macrophages promotes acute intestinal injury in neonatal necrotizing enterocolitis
Bo Shi1, Cheng-Jie Lyu1, Zhen-Kai Le1
1Department of Neonatal Surgery, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, China.
Background:
Macrophages are involved in various immune inflammatory disease conditions. This study aimed to investigate the role and mechanism of macrophages in regulating acute intestinal injury in neonatal necrotizing enterocolitis (NEC).
Methods:
CD68, nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain-containing 3 (NLRP3), cysteine aspartate-specific protease-1 (caspase-1), and interleukin-1β (IL-1β) in paraffin sections of intestinal tissues from NEC and control patients were detected with immunohistochemistry, immunofluorescence, and western blot. Hypertonic pet milk, hypoxia and cold stimulation were used to establish a mouse (wild type and Nlrp3-/-) model of NEC. The mouse macrophage (RAW 264.7) and rat intestinal epithelial cell-6 lines were also cultured followed by various treatments. Macrophages, intestinal epithelial cell injuries, and IL-1β release were determined.
Results:
Compared to the gut "healthy" patients, the intestinal lamina propria of NEC patients had high macrophage infiltration and high NLRP3, caspase-1, and IL-1β levels. Furthermore, in vivo, the survival rate of Nlrp3-/- NEC mice was dramatically improved, the proportion of intestinal macrophages was reduced, and intestinal injury was decreased compared to those of wild-type NEC mice. NLRP3, caspase-1, and IL-1β derived from macrophages or supernatant from cocultures of macrophages and intestinal epithelial cells also caused intestinal epithelial cell injuries.
Conclusions:
Macrophage activation may be essential for NEC development. NLRP3/caspase-1/IL-1β cellular signals derived from macrophages may be the underlying mechanism of NEC development, and all these may be therapeutic targets for developing treatments for NEC.
Insights
Macrophage activation drives necrotizing enterocolitis (NEC) development. Targeting the NLRP3/caspase-1/IL-1β pathway in macrophages offers a potential therapeutic strategy for NEC.
Area of Science:
- Immunology
- Gastroenterology
- Neonatal Medicine
Background:
- Macrophages play a critical role in immune and inflammatory responses.
- Necrotizing enterocolitis (NEC) is a severe gastrointestinal disease affecting neonates, often involving inflammation.
Purpose of the Study:
- To investigate the role of macrophages in neonatal acute intestinal injury.
- To elucidate the underlying mechanisms of macrophage involvement in NEC pathogenesis.
Main Methods:
- Immunohistochemistry, immunofluorescence, and western blot were used to detect key inflammatory markers (CD68, NLRP3, caspase-1, IL-1β) in human NEC and control tissues.
- A mouse model of NEC was established using hypertonic pet milk, hypoxia, and cold, with wild-type and Nlrp3 knockout mice utilized.
- In vitro studies involved cultured mouse macrophages (RAW 264.7) and rat intestinal epithelial cells (IEC-6) to assess cell injury and cytokine release.
Main Results:
- NEC patients exhibited increased macrophage infiltration and elevated levels of NLRP3, caspase-1, and IL-1β in intestinal tissues compared to controls.
- Nlrp3 knockout mice showed improved survival, reduced intestinal macrophage proportion, and decreased injury in the NEC model.
- Macrophage-derived NLRP3, caspase-1, and IL-1β were found to induce intestinal epithelial cell injury.
Conclusions:
- Macrophage activation is crucial for the development of NEC.
- The NLRP3/caspase-1/IL-1β signaling pathway originating from macrophages is a key mechanism in NEC.
- This pathway represents a potential therapeutic target for NEC treatment.
