A novel serum biomarker molecule for heart failure progression： VDAC3 protects against heart failure by aediating SLC25A11 stability and repairing ATP synthesis

Background Reducing mortality and readmission in progressive heart failure (HF) remains a major clinical challenge. The heart relies on mitochondrial oxidative phosphorylation (OXPHOS) for approximately 95% of ATP demand. Voltage-dependent anion channel 3 (VDAC3), the least characterized member of the VDAC family, serves as a bridge protein connecting the outer and inner mitochondrial membranes. However, its role in stabilizing mitochondrial function and counteracting progressive HF is unknown.Purpose To investigate whether VDAC3 functions as a novel biomarker and therapeutic target in the progression of HF, and to elucidate the underlying mitochondrial mechanisms. Methods Serum VDAC3 was measured by ELISA in 132 HF patients. Cardiac-specific VDAC3 overexpression or knockdown was achieved using AAV9-cTNT vectors in C57BL/6J mice subjected to transverse aortic constriction (TAC). Cardiac function and remodeling were assessed by echocardiography, histology, and WGA staining. Mitochondrial function in neonatal rat ventricular myocytes (NRVMs) was evaluated via Seahorse XF Analyzer, mitochondrial membrane potential (ΔΨm), and ROS assays. VDAC3-interacting proteins were identified through co-immunoprecipitation (Co-IP) and LC-MS/MS. Metabolomics was performed on cardiac tissue from sham and TAC mice. Results VDAC3 expression was downregulated in serum and heart tissue of HF patients, hypertrophic mouse models (TAC or isoproterenol-induced), and phenylephrine (PE)-stimulated NRVMs. Serum VDAC3 positively correlated with LVEF and negatively with NT-proBNP. Cardiac-specific VDAC3 knockout exacerbated left ventricular dysfunction, whereas overexpression preserved LVEF, LVFS, and attenuated hypertrophy and fibrosis. Consistently, VDAC3 knockdown aggravated hypertrophy in NRVMs, which was reversed by overexpression. Mechanistically, Co-IP/LC-MS/MS identified solute carrier family 25 member 11 (SLC25A11) as a direct VDAC3-binding partner at lysine 73. VDAC3 stabilized SLC25A11 protein by blocking its proteasomal degradation, thereby enhancing aspartate and α-ketoglutarate flux into the TCA cycle and boosting ATP production and redox homeostasis. SLC25A11 knockdown abolished VDAC3-mediated cardioprotection. Furthermore, VDAC3 reduction in progressive hypertrophy was linked to β-hydroxybutyrylation (Kbhb) at lysine 236, which promoted its degradation via the proteasomal pathway. Conclusions VDAC3 is a novel circulating biomarker and a central therapeutic node in HF progression. VDAC3 maintains mitochondrial bioenergetics by stabilizing SLC25A11, and its loss through Kbhb modification at K236 represents a targetable mechanism for future therapeutic intervention.A graphical abstract