Downregulation of ARNTL in renal tubules of diabetic db/db mice reduces kidney injury by inhibiting ferroptosis

Background: The prevalence of ferroptosis in diabetic kidney tubules has been documented, yet the underlying mechanism remains elusive. The aim of this study was to ascertain the pivotal gene linked to ferroptosis and establish a novel target for the prevention and management of diabetic kidney disease (DKD). Methods: Transcriptomics data (GSE184836) from DKD mice (C57BLKS/J) were retrieved from the GEO database and intersected with ferroptosis-related genes from FerrDb. Then, differentially expressed genes associated with ferroptosis in the glomeruli and tubules were screened. Gene ontology analysis and protein-protein interaction network construction were used to identify key genes. Western blotting and real-time quantitative polymerase chain reaction were employed to validate the expression in the same model. Aryl hydrocarbon receptor nuclear translocator-like protein 1 (ARNTL) expression in patients and mice with DKD was assessed using immunohistochemistry staining. ARNTL knockdown in C57BLKS/J mice was established and plasma malonaldehyde, superoxide dismutase, and renal pathology were analyzed. The efficacy of ARNTL knockdown was evaluated using proteomics analysis. Mitochondrial morphology was observed using transmission electron microscopy. Results: ARNTL was screened by bioinformatics analysis and its overexpression verified in patients and mice with DKD. ARNTL knockdown reduced oxidative stress in plasma. Kidney proteomics revealed that ferroptosis was inhibited. The reduction of the classic alteration in mitochondrial morphology associated with ferroptosis was also observed. Gene set enrichment analysis demonstrated that the downregulation of the TGF8 pathway coincided with a decrease in collagen protein and TGF81 levels. Conclusions: The ferroptosis-associated gene ARNTL is a potential target for treating DKD.