IGFBP2 serves as a coenzyme A sensor to regulate cardiomyocyte ferroptosis in cardiac ischemia-reperfusion injury
J Wang, R Wu, B ShiAbstract
Background
Myocardial ischemia/reperfusion (I/R) injury remains a major clinical challenge. Ferroptosis, a form of regulated cell death characterized by iron-dependent lipid peroxidation, has emerged as a critical mechanism underlying cardiomyocyte loss following I/R. Coenzyme A (CoA) is essential for energy metabolism; however, its specific role in modulating ferroptosis during I/R injury remains poorly understood.
Purpose
This study aims to characterize the alteration of CoA metabolism during myocardial I/R injury, identify CoA-binding proteins that regulate ferroptotic signaling, and establish the CoA-IGFBP2 axis as a target to attenuate cardiomyocyte loss and preserve cardiac function following I/R.
Methods
Ferroptosis was induced in neonatal mouse cardiomyocytes (NMCMs) via cystine deprivation and assessed by cell viability and lipid peroxidation assays. Multi-modal metabolomics (untargeted, spatial, and targeted) profiled CoA alterations in vitro and in vivo. The functional role of CoA was determined via CoA supplementation and genetic modulation of PANK1 (the rate-limiting CoA biosynthetic enzyme) or NUDT8 (a key enzyme in CoA catabolism). CoA-binding proteins were screened by limited proteolysis-mass spectrometry (LIP-MS) and validated via SPR, CETSA and pull down assays. The function of the lead candidate, IGFBP2, was confirmed using siRNA and cardiomyocyte-specific knockout (IGFBP2-cKO) mice. Furthermore, mass spectrometry was employed to characterize oxidative conformational changes and disulfide bond remodeling in IGFBP2.
Results
Cystine deprivation induced significant ferroptosis in NMCMs, accompanied by marked downregulation of the CoA biosynthetic pathway. Restoring CoA levels either through supplementation or genetic modulation of PANK1/NUDT8 successfully rescued NMCMs from ferroptosis. In murine I/R hearts, spatial and targeted metabolomics revealed significant collapse in free CoA and multiple acyl-CoA species. Consequently, PANK1 overexpression or NUDT8 knockdown significantly reduced infarct size and improved cardiac function. Mechanistically, LiP-MS identified IGFBP2 as a intracellular CoA-binding protein. Cystine deprivation triggered oxidative disulfide bond remodeling of IGFBP2 and suppressed the BRCA1-associated DNA damage response, thereby amplifying ferroptosis. Conversely, CoA binding prevented this deleterious conformational change and inhibited this pro-ferroptosis cascade. Finally, IGFBP2-cKO mice exhibited reduced ferroptosis and improved cardiac function following I/R.
Conclusions
This study delineates dynamic CoA depletion during myocardial I/R and identifies IGFBP2 as an intracellular CoA-binding protein. By preventing IGFBP2 oxidative disulfide remodeling, CoA acts as a critical endogenous suppressor of ferroptosis. The CoA-IGFBP2 axis represents a promising therapeutic target for mitigating myocardial I/R injury.