Fructose directly remodels the translocase of the outer membrane to impair oxidative phosphorylation in podocytes

Excessive dietary fructose consumption contributes to the rapidly increasing prevalence of obesity, metabolic syndrome, and chronic kidney disease worldwide, and accumulating preclinical evidence has confirmed that excess fructose exposure provokes severe mitochondrial dysfunction, which serves as a critical upstream driver of progressive metabolic disturbance and renal tissue injury. Conventionally, fructose-induced mitochondrial damage is thought to originate from harmful intermediate metabolites produced during intracellular fructose catabolism, while the potential direct pathogenic effect of intact unmetabolized fructose is largely overlooked. It remains unclear whether free fructose can directly target core mitochondrial complexes to initiate functional defects independent of its metabolic breakdown. Here, we report a fructose metabolism-independent mechanism in which fructose structurally remodels the translocase of the outer membrane (TOM) complex, obstructing the import of nuclear-encoded mitochondrial proteins and inhibiting mitochondrial ribosome biogenesis as well as oxidative phosphorylation. In vitro biochemical assays confirm that fructose non-covalently binds to TOM22 and induces subtle but functionally critical conformational changes in the TOM complex, thereby blocking the transmembrane translocation of mitochondrial ribosome subunits. Notably, disrupting the fructose-TOM22 binding efficiently recovers abnormal ribosome trafficking, restores compromised oxidative phosphorylation, and ameliorates mitochondrial dysfunction and glomerular pathological lesions in fructose-treated podocytes and mouse injury models. Our findings establish an innovative mechanistic paradigm that fructose acts as a direct allosteric modulator of mitochondrial membrane complexes, identifying TOM structural remodeling as a previously unrecognized molecular trigger of fructose-associated mitochondrial and metabolic disorders.