Obesity suppresses neutrophil-dependent itaconate signaling promoting ferroptosis in acute pancreatitis.

Obesity is a well-established risk factor for increased severity and mortality in acute pancreatitis. However, the mechanisms by which obesity alters pancreatic immune regulation and favors the progression of acute pancreatitis are not elucidated yet. Here, we identify a neutrophil-driven immune-metabolic pathway that controls ferroptosis during pancreatic inflammation. We show that infiltrating myeloid cells represent the principal source of the immunometabolite itaconate during acute pancreatitis. Through paracrine transfer via the SLC13A3 transporter, myeloid-derived itaconate protects pancreatic acinar cells from ferroptosis by sustaining NRF2-dependent antioxidant responses. Obesity disrupts this protective axis by suppressing ACOD1 expression in infiltrating neutrophils. Proteomic profiling of pancreatic neutrophils from obese mice confirmed reduced ACOD1 abundance and decreased expression of enzymes linked to the tricarboxylic acid cycle and pyruvate metabolism. This metabolic reprogramming limits itaconate production and weakens NRF2-driven redox defenses, leading to downregulation of the xCT-GPX4 ferroptosis-protective pathway and increased lipid peroxidation in the pancreas of obese mice with pancreatitis. Pharmacological restoration of itaconate signaling with the cell-permeable derivative 4-octyl itaconate reactivates NRF2 signaling, the xCT-GPX4 antioxidant axis, and the trans-sulfuration pathway, mitigating pancreatic injury. Together, these findings identify neutrophil-derived itaconate as a key modulator of ferroptosis susceptibility and reveal immune cell metabolism as a critical determinant of obesity-associated severity in acute pancreatitis.