Coordinated interferon-γ/tumor necrosis factor axis drives selective loss of activated enteric glia in inflammatory bowel diseases

BACKGROUND & AIMS: Enteric glial cells regulate gastrointestinal homeostasis and inflammation. Although activated enteric glial cells have been shown to support epithelial and immune balance in preclinical models, their functional status and turnover in inflammatory bowel diseases remain poorly defined. This study aimed to identify enteric glial cell activation markers and assess their susceptibility to cytokine-driven death in inflammatory bowel diseases.

METHODS: We analyzed 390 intestinal samples from patients with inflammatory bowel disease using bulk and single-nucleus RNA sequencing and validated findings across public datasets comprising over 1160 patients and 19,000 enteric glial cell transcriptomes. We used multiple mouse models of gut inflammation, reporter-based glial sorting, transcriptomics, and glia-specific Casp8 deletion to dissect mechanisms of enteric glial cell activation and death. Ex vivo stimulation of sorted enteric glial cells was used to assess cytokine-specific effects.

RESULTS: We identified novel inflammatory bowel disease subtype- and location-specific enteric glial cell activation markers, including osteopontin (SPP1), enriched in ulcerative colitis. Single-nucleus and single-cell data revealed that activated enteric glial cell clusters selectively upregulate cell death signatures with inflammatory bowel disease enteric glial cells displaying necroptosis via phosphorylation of mixed lineage kinase domain-like pseudokinase. In mice, acute T helper 1 cell/T helper 17-driven inflammation rapidly induced enteric glial cell activation and necroptosis, impairing intestinal motility. Ex vivo, interferon-γ and tumor necrosis factor costimulation, but not individual cytokines, induced mixed lineage kinase domain-like pseudokinase-dependent necroptosis in enteric glial cells. Casp8-deficient enteric glial cells ere hypersensitive to tumor necrosis factor-induced death, confirming a Caspase-8-dependent survival checkpoint.

CONCLUSIONS: A proportion of activated enteric glial cells are selectively eliminated in inflammatory bowel disease via cytokine-mediated necroptosis, driven by a coordinated interferon-γ/tumor necrosis factor axis. This process compromises enteric glial support functions and may contribute to inflammatory bowel disease-associated dysmotility. Targeting glial survival may represent a novel therapeutic avenue.