PINK1 deacetylation by emodin-induced SIRT3 upregulation alleviates acute kidney injury by Inhibition of ferroptosis

Background Acute kidney injury (AKI), characterized by rapid renal dysfunction and high mortality, is critically driven by ferroptosis, an iron-dependent form of cell death. While PTEN-induced kinase 1 (PINK1) and sirtuin 3 (SIRT3) are implicated in mitochondrial homeostasis and ferroptosis regulation, their mechanistic interplay in AKI remains unclear. This study investigated the role of emodin, a natural anthraquinone, in alleviating AKI via SIRT3-mediated PINK1 deacetylation and ferroptosis suppression, focusing on mitochondrial integrity, transferrin (TF) interaction, and redox balance. Materials and methods Male C57BL/6 mice ( n  = 6/group), PINK1⁻/⁻, and SIRT3⁻/⁻ mice were pretreated with emodin (40–160 mg/kg, 3 days) before LPS-induced AKI (15 mg/kg). Human renal tubular HK-2 cells were treated with emodin (10–40 µg/ml) and Erastin (0.4 µM, 24 h). Assays included RNA sequencing, immunoprecipitation-mass spectrometry (IP-MS), histopathology (H&E/PAS/PB-DAB staining), ROS/Fe²⁺/GSH quantification, and immunoblotting. Statistical analysis used ANOVA and Student’s t-test. Results Emodin reduced serum creatinine and urea in AKI mice, alongside decreased tubular injury and apoptosis. RNA-seq identified ferroptosis as the central pathway, with emodin upregulating PINK1 expression. IP-MS revealed emodin disrupted PINK1-TF binding via SIRT3-mediated deacetylation, reducing Fe²⁺ accumulation and restoring GPX4 levels. In SIRT3⁻/⁻ and PINK1⁻/⁻ models, emodin’s protective effects were abolished, confirming pathway dependency. Conclusion Emodin mitigates AKI by activating the SIRT3/PINK1 axis, suppressing ferroptosis through cytoplasmic PINK1 deacetylation and TF interaction disruption. These findings highlight SIRT3/PINK1 as a therapeutic target and emodin as a potential agent for AKI management.