# The BHMT2/MAT1A/AHSG axis promotes M1 macrophage activation and exacerbates necrotizing enterocolitis

## TL;DR

This study identifies a pathway involving three genes that worsens intestinal inflammation in premature infants, suggesting a new target for treatment.

## Contribution

The BHMT2/MAT1A/AHSG axis is newly identified as a driver of M1 macrophage activation in NEC.

## Key findings

- BHMT2 and MAT1A regulate AHSG expression through methylation mechanisms in intestinal cells.
- Targeting BHMT2, MAT1A, or AHSG reduces M1 macrophage activation and intestinal damage in NEC models.
- Overexpression of these genes promotes M1 macrophage polarization and inflammation.

## Abstract

Background Necrotizing enterocolitis (NEC) is a devastating intestinal disorder in premature infants, characterized by inflammation and tissue injury. Identifying key regulatory pathways contributing to NEC pathogenesis is essential for developing targeted therapeutic strategies. Methods Transcriptomic analysis of NEC and control samples identified a core regulatory module comprising AHSG, BHMT2, and MAT1A. Their expression and functional roles were investigated in human primary intestinal epithelial cells (HPIECs), a transwell co-culture system with THP-1 macrophages, and a mouse model of NEC. Molecular techniques, including RT-qPCR, Western blotting, ELISA, chromatin immunoprecipitation, and flow cytometry were employed to decipher the functional mechanism of this regulatory module. Results AHSG, BHMT2, and MAT1A were upregulated in NEC samples and LPS-stimulated HPIECs. BHMT2 and MAT1A regulated AHSG expression through S-adenosylmethionine production and histone methylation. In the co-culture system, silencing BHMT2, MAT1A, or AHSG in LPS-stimulated HPIECs attenuated M1 macrophage polarization, inflammatory cytokine production, and invasive capacity of THP-1 cells. Conversely, overexpressing these genes in HPIECs promoted M1 macrophage activation. In the NEC mouse model, targeting BHMT2, MAT1A, or AHSG alleviated intestinal tissue damage, inflammation, and M1 macrophage polarization. Conclusion The BHMT2/MAT1A/AHSG axis in intestinal epithelial cells orchestrates M1 macrophage activation and contributes to the exacerbation of NEC. Targeting this pathway may represent a potential therapeutic strategy for NEC management.

The online version contains supplementary material available at 10.1038/s41598-025-22915-1.