Highlights
• Mitochondrial perturbation of the intestinal epithelium induces tissue injury
• Loss of IL-10 and AhR-related host mechanisms accelerate injury and inflammation
• Mitochondrial dysfunction induces dysbiosis and expansion of Bacteroides spp.
• Metabolic injury gene signature discriminates inflamed versus non-inflamed IBD samples
Summary
Mitochondrial dysfunction is associated with inflammatory bowel diseases (IBDs). To understand how microbial-metabolic circuits contribute to intestinal injury, we disrupt mitochondrial function in the epithelium by deleting the mitochondrial chaperone, heat shock protein 60 (Hsp60Δ/ΔIEC). This metabolic perturbation causes self-resolving tissue injury.
Regeneration is disrupted in the absence of the aryl hydrocarbon receptor (Hsp60Δ/ΔIEC;AhR−/−) involved in intestinal homeostasis or inflammatory regulator interleukin (IL)-10 (Hsp60Δ/ΔIEC;Il10−/−), causing IBD-like pathology. Injury is absent in the distal colon of germ-free (GF) Hsp60Δ/ΔIEC mice, highlighting bacterial control of metabolic injury. Colonizing GF Hsp60Δ/ΔIEC mice with the synthetic community OMM12 reveals expansion of metabolically flexible Bacteroides, and B. caecimuris mono-colonization recapitulates the injury. Transcriptional profiling of the metabolically impaired epithelium reveals gene signatures involved in oxidative stress (Ido1, Nos2, Duox2).
These signatures are observed in samples from Crohn’s disease patients, distinguishing active from inactive inflammation. Thus, mitochondrial perturbation of the epithelium causes microbiota-dependent injury with discriminative inflammatory gene profiles relevant for IBD.
