NR4A1 negatively regulates ferroptosis of pancreatic β-cells induced by Erastin.

AIMS: Ferroptosis caused by metabolic stress is a main contributor to pancreatic β-cell injury in type 2 diabetes. Orphan nuclear receptor NR4A1 can be activated by various stimuli and stressors, but its role remains unclear in pancreatic β-cell ferroptosis. This study focuses on how NR4A1 transcriptionally regulates pancreatic β-cell ferroptosis and reveals its underlying network. MATERIALS AND METHODS: The Metabolic parameters, pancreatic morphological alterations and ferroptotic phenotypes were assessed in NR4A1 pancreatic-specific knockout (cKO) mice and flox mice under a high-fat diet. Ferroptosis markers, including ROS, Fe2+, MDA and GSH, were detected in MIN6 cells treated with Cytosporone B (CsnB) and NR4A1 overexpression cells (OV cells). PCR array was used to identify differentially expressed genes in OV cells. KEY FINDINGS: Our data showed that under high-fat diet feeding, cKO mice exhibited exacerbated weight gain, hyperglycemia, impaired glucose tolerance, and reduced insulin secretion, accompanied by compensatory islet hypertrophy, a decreased β-cell proportion, and a distinct pancreatic ferroptosis phenotype. In MIN6 cells, the ferroptosis inducer Erastin triggered ROS/Fe2+/MDA accumulation, GSH exhaustion, accompanied by downregulated expression of GPX4 and SLC7A11 (xCT), as well as upregulated levels of PTGS2 (COX2) and ACSL4. These effects were reversed by NR4A1 overexpression or treatment with CsnB in MIN6 cells. Notably, xCT and GPX4 transcript levels did not show a significant increase upon NR4A1 overexpression. SIGNIFICANCE: Our findings demonstrate that NR4A1 negatively regulates pancreatic β-cell ferroptosis, suggesting its promise as a therapeutic target to safeguard β-cell survival in type 2 diabetes.