CYBB-Mediated Ferroptosis Drives Podocyte Injury in Lupus Nephritis and Represents a Therapeutic Target

Lupus nephritis (LN) is a major cause of kidney failure in systemic lupus erythematosus, with podocyte injury being a key determinant of proteinuria and poor renal outcome. Ferroptosis, an iron-dependent form of regulated cell death, has been implicated in kidney diseases, but its role in LN remains unclear.

We integrated in vivo experiments using MRL/lpr mice, in vitro assays with immortalized podocytes (MPC5), and transcriptomic analysis of human glomerular datasets (GSE32591). Ferroptosis involvement was evaluated by ferrostatin-1 (Fer-1) treatment, measurement of ferroptosis markers, and assessment of podocyte proteins. Bioinformatic analyses (differential expression, WGCNA, LASSO regression, and FerrDb integration) identified candidate ferroptosis regulators, followed by functional validation of CYBB via siRNA knockdown and overexpression.

Progressive nephritis in MRL/lpr mice showed iron overload, lipid peroxidation, glutathione depletion, and GPX4 downregulation, leading to podocyte loss and proteinuria. Fer-1 treatment markedly ameliorated renal pathology and preserved podocyte integrity. Human LN datasets identified CYBB as a ferroptosis-related hub gene upregulated in disease. CYBB expression correlated with renal dysfunction and oxidative injury, while in vitro assays confirmed that CYBB overexpression enhanced ROS generation and ferroptotic podocyte damage, whereas CYBB knockdown or Fer-1 reversed these effects.

These findings identify CYBB-mediated ferroptosis as a key driver of podocyte injury in LN. By promoting ROS generation and lipid peroxidation, CYBB serves as a mechanistic link between oxidative stress and ferroptotic cell death. Both pharmacological and genetic inhibition of CYBB mitigated ferroptosis, preserved podocyte integrity, and improved renal function, highlighting CYBB as a promising therapeutic target in lupus nephritis.