HIF1A transcriptionally activates CDKN1A to drive ferroptosis in skeletal muscle ischaemia-reperfusion injury

Background: Skeletal muscle ischaemia-reperfusion (I/R) injury involves complex redox dysregulation with limited treatments. Although ferroptosis contributes to other organ I/R injuries, its role and regulation in skeletal muscle remain unclear. This study aimed to investigate the role and regulatory mechanism of ferroptosis in skeletal muscle I/R injury, specifically focusing on whether hypoxia-inducible factor 1 alpha (HIF1A) transcriptionally activates cyclin-dependent kinase inhibitor 1a (CDKN1A/p21) to drive this process. Methods: overexpression was performed for rescue experiments. Ferroptosis was assessed by examining mitochondrial ultrastructure, quantifying lipid peroxidation, and evaluating the expression of key proteins: glutathione peroxidase 4 (GPX4), acyl-CoA synthetase long-chain family member 4 (ACSL4), and prostaglandin-endoperoxide synthase 2 (PTGS2). Clinical relevance was evaluated by co-expression analysis of HIF1A and CDKN1A in human I/R-affected muscle biopsies. Results: knockdown, confirming CDKN1A as a key downstream effector. Strong positive co-expression of HIF1A and CDKN1A was observed in human I/R biopsies (Spearman's r = 0.543, p = 0.006). Mechanistically, the HIF1A-CDKN1A axis exacerbated redox stress via glutathione depletion and intracellular free iron accumulation. Conclusion: . This HIF1A-CDKN1A axis drives ferroptosis by disrupting redox homeostasis. Targeting HIF1A and CDKN1A within this pathway provides two complementary molecular entry points for mitigating skeletal muscle I/R injury. The Translational Potential of this Article: Targeting the HIF1A-CDKN1A axis offers a promising therapeutic approach to reduce skeletal muscle damage and improve clinical outcomes after ischaemia-reperfusion injury.