Multi-layer transcriptomic analyses identify a mucin-associated epithelial program linked to innate inflammatory...

Area of Science:

• Gastroenterology
• Molecular Biology
• Immunology

Background:

• Ulcerative colitis (UC) involves a complex interplay between epithelial barrier dysfunction and innate immune activation.
• The specific epithelial glycosylation pathways that maintain mucus homeostasis and prevent inflammatory injury in UC are not fully understood.

Purpose of the Study:

• To identify mucin-associated epithelial genes involved in UC pathogenesis.
• To investigate the role of the identified genes, particularly GALNT12, in epithelial barrier function and immune response in UC.

Main Methods:

• Integrated bulk, single-cell, and spatial transcriptomic analyses of UC patient cohorts (GSE107499).
• Functional validation using cell line models (HT29-19A) with gene knockdown and cytokine stimulation.
• Analysis of gene expression, immune cell infiltration, cellular communication, and inflammatory markers.

Main Results:

• Fifteen dysregulated mucin-type O-glycosylation and associated genes were identified, with GALNT12 prioritized.
• Low GALNT12 expression correlated with increased inflammatory signaling (TNFA, IL6-JAK-STAT3), immune cell infiltration, and compromised epithelial barrier function.
• GALNT12-high epithelial cells showed enhanced communication and secretory functions, with GALNT12-high niches associated with lower inflammation.
• GALNT12 knockdown in cell lines exacerbated TNF-α-induced barrier damage and inflammatory mediator release.

Conclusions:

• A GALNT12-centered epithelial program is critical for maintaining epithelial barrier resilience and modulating innate immune responses at the gut barrier in UC.
• GALNT12 plays a protective role against inflammatory injury, and its dysfunction contributes to UC pathogenesis.
• Targeting GALNT12 may offer a therapeutic strategy for enhancing epithelial barrier function in ulcerative colitis.