Targeting PSAT1 in diabetic kidney disease: a ferroptosis-driven strategy for precision therapy.

Diabetic kidney disease (DKD) involves mitochondrial dysfunction and ferroptosis, yet the convergence of these processes at the gene level remains unclear. We first analyzed human renal transcriptomic data (GSE30528) to identify differentially expressed genes (DEGs). DEGs associated with both mitophagy and ferroptosis (DEMFRGs) were extracted. Protein-protein interaction (PPI) networks, the MCC algorithm, and LASSO regression were used to screen hub genes. Immune infiltration was assessed via CIBERSORT. Diagnostic performance of hub genes was evaluated using ROC curves in GSE30528 and validated in an independent dataset (GSE96804). Experimental validation was conducted in a high-fat diet/STZ-induced DKD mice and high-glucose-treated HK-2 cells. Drug prediction were predicted by Network Analyst platform with DrugBank. Molecular docking for drug prediction was performed using AutoDock Vina. We identified 12 DEMFRGs, of which 9 were hub genes (DUSP1, ASNS, FBXW7, HMOX1, NFE2L2, SIRT1, STEAP3, PSAT1, PIK3CA). Enrichment analysis linked them to ferroptosis and the PI3K-Akt pathway. PSAT1 emerged as a novel, dual-pathway regulator, significantly correlated with immune cell infiltration (e.g., Eosinophils, r = 0.46). A prognostic model based on the 9 hub genes achieved an AUC of 1.000 (GSE30528 and GSE96804). PSAT1 is predominantly localized to renal tubules, which is validated by both experimental studies and box plots from GSE21785 datasets. PSAT1 exhibited strong diagnostic power (AUC = 0.79) and was experimentally confirmed to be upregulated in DKD models and Nephroseq V5 database. Molecular docking demonstrated strong binding of Pyridoxal phosphate and L-Glutamate to PSAT1(binding energy: -7.0 kcal/mol and − 5.7 kcal/mol). This study provides the first integrative analysis linking mitophagy and ferroptosis in DKD, identifies key PSAT1 gene and immune interactions, and proposes druggable targets, laying the groundwork for precision therapeutics in DKD.