Intra-mitochondrial glycolysis maintains mitochondrial function and underlies the pathogenesis of retinitis pigmentosa

Glycolysis is classically defined as a cytoplasmic process. Here, in our investigation of mitochondrial dysfunction in Retinitis Pigmentosa (RP), we report the unexpected discovery of a complete and functional glycolytic pathway operating inside mitochondria. Through CoIP-MS, polysome profiling, and [U-13C] glucose isotope tracing, we demonstrate that key glycolytic enzymes are locally translated and metabolically active within the organelle. Mechanistically, we show that the VWA8-PHB2-GRP75 complex is responsible for anchoring these enzymes, thereby sustaining intra-mitochondrial glycolysis and preserving mitochondrial function by regulating NAD+ levels and reactive oxygen species (ROS) homeostasis. In vivo, Vwa8 knockout in both mice and zebrafish abolishes this metabolic safeguard, leading to RP-like phenotypes that can be partially rescued by reactivating mitochondrial glycolysis. Collectively, these findings redefine the spatial compartmentalization of glucose metabolism and establish mitochondrial glycolysis as a therapeutic target for mitochondrial diseases. Glycolysis has long been considered a process restricted exclusively to the cytoplasm. Here, the authors show that a functional glycolytic pathway operates inside mitochondria to maintain organelle health, identifying the VWA8-PHB2-GRP75 complex as a critical regulator that offers a promising therapeutic target for mitochondrial diseases like retinitis pigmentosa.