PGAM1-dependent VDAC1 oligomerization disrupts mitochondrial quality control to drive doxorubicin cardiotoxicity via the cGAS-STING-ferroptosis axis

Objectives: Doxorubicin (Dox) is a potent chemotherapeutic agent whose clinical use is limited by severe cardiotoxicity. The underlying molecular mechanisms remain incompletely understood. This study aimed to investigate the role of the phosphoglycerate mutase 1 (PGAM1)/voltage-dependent anion channel 1 (VDAC1) axis in early-stage Dox-induced cardiotoxicity, focusing on its impact on mitochondrial quality control (MQC), endoplasmic reticulum (ER) stress, and the subsequent activation of innate immune signaling.

Methods: We established a short-term cumulative Dox-induced cardiomyopathy model using wild-type and cardiomyocyte-specific PGAM1 knockout (PGAM1-CKO) mice. Cardiac function was assessed by echocardiography. In vitro experiments were performed on neonatal mouse cardiomyocytes (NMCMs) and HL-1 cells. Molecular techniques including Western blotting, immunofluorescence, co-immunoprecipitation, and quantitative PCR were used to dissect the signaling pathway. Key pathway components were validated using specific pharmacological inhibitors and activators.

Results: Dox treatment significantly upregulated PGAM1 expression in cardiomyocytes. PGAM1-CKO mice were protected from Dox-induced cardiac dysfunction, fibrosis, and inflammation. Mechanistically, Dox-induced PGAM1 promoted the pathological oligomerization of VDAC1. This PGAM1-VDAC1 interaction triggered the collapse of MQC and induced ER stress, leading to the leakage of mitochondrial DNA (mtDNA) into the cytosol. The released cytosolic mtDNA subsequently activated the cGAS-STING innate immune pathway, which we identified as a critical upstream driver of cardiomyocyte Ferroptosis. Pharmacological induction of VDAC1 oligomerization or STING activation abolished the cardioprotective effects observed in PGAM1-CKO mice.

Conclusion: Our findings reveal a novel PGAM1/VDAC1 signaling axis that triggers early Dox-induced cardiotoxicity. This axis disrupts mitochondrial homeostasis, leading to mtDNA release, which activates the cGAS-STING pathway and ultimately culminates in cardiomyocyte Ferroptosis. Targeting the PGAM1/VDAC1 interaction presents a promising therapeutic strategy to mitigate Dox-induced cardiac injury.