Targeting OTUD7A-HINT1 deubiquitination activates mTOR signaling for CNS regeneration

Abstract Axon regeneration in the central nervous system (CNS) remains limited, imposing severe constraints on functional recovery after injury. Here, we reveal that the deubiquitinase OTU deubiquitinase 7 A (OTUD7A) critically regulates CNS regeneration by modulating histidine triad nucleotide-binding protein 1 (HINT1) stability. OTUD7A stabilizes HINT1 protein through specific removal of K63-linked ubiquitin chains at lysine 7. Screening of the small-molecule deubiquitinase inhibitor PR-619 identified HINT1 as a key ubiquitination-regulated target. Notably, genetic knockdown of Hint1 alone was sufficient to improve RGC survival and promote optic nerve regeneration, thereby activating mTOR signaling, while PR-619 administration enhanced tissue preservation and axon repair after spinal cord injury. A multi-gene therapeutic strategy further enhanced optic nerve regeneration in the optic nerve crush (ONC) model. These findings identify the OTUD7A–HINT1–mTOR axis as a potential therapeutic target in CNS regeneration.