Western diets (WD), high in saturated fats such as palmitic acid (PA), promote enteric neurodegeneration and motility disorders. Using murine models, in vitro systems, and human myenteric ganglia, we investigated whether WD and PA drive iron-dependent ferroptotic injury in the enteric nervous system. Mice were fed control diet (CD) or WD for 12 weeks, with or without systemic AAV9-MaCPNS2 delivery of Nfe2l2 to enteric neurons. Colonic motility was assessed by bead-expulsion assay. Ferroptosis was assessed using convergent readouts including iron dysregulation (TfR1, FTH-1, labile and mitochondrial Fe2+), lipid peroxidation (C11-BODIPY and 4-HNE), GPX4 suppression, and pharmacologic inhibition by ferrostatin-1 (Fer-1) in primary enteric neurons, murine myenteric plexuses, and human networks of myenteric ganglia (nhMPG). WD-fed mice exhibited delayed colonic transit, increased TfR1 and FTH-1, and vulnerability of nNOS neurons; these changes were reversed by Nfe2l2 overexpression. RNA-seq of PA-treated IM-FEN neuronal cells revealed disrupted of neurotransmitter signaling, reduced mitochondrial and antioxidant programs, and increased iron import and lipid peroxidation signatures. PA increased labile iron, mitochondrial ROS, membrane depolarization, Ca2+ dysregulation, 4-HNE, and Mfrn2, while Fer-1 preserved mitochondrial integrity, viability, and ENS function. In human nhMPG, PA induced enteric neuronal iron loading and ferroptosis, supporting translational relevance to diet-associated enteric neuropathy.
Balasubramaniam et al. (Tue,) studied this question.