Stage-specific extracellular vesicle cargo from Schwann cells orchestrates peripheral nerve regeneration

Schwann cells (SCs) play a critical role in peripheral nerve regeneration, undergoing dynamic phenotype transitioning from myelinating to repair stages following injury. While SC-derived extracellular vesicles (SC-EVs) have emerged as key mediators of intercellular communication during nerve repair, their stage-specific molecular cargo and functional roles remained incomplete understood. Here, we delineate protein, microRNA and lncRNA landscapes of SC-EVs across distinct differentiation stages, including immature, myelinating, and repair phenotypes, using an in vitro model of primary rat SCs. We show that myelinating SC-EVs are enriched with reprogramming factor SOX2 and neurotrophin receptor p75NTR, while repair SC-EVs carry distinct microRNAs predicted to modulate genes involved in myelin ensheathment, neuronal differentiation and neurogenesis. Moreover, repair SC-EVs contain long non-coding RNAs (lncRNAs) that may regulate miRNA activity. These findings reveal a novel mechanism by which SC-EVs orchestrate neuronal regeneration through stage-specific molecular cargo, and establishes a foundational model for investigating SC plasticity in peripheral nerve repair Schematic of the in vitro differentiation model used to induce Schwann cells (SCs) to induce myelination, followed by reversion to a repair phenotype. Rat primary SCs were treated with 1 mM dbcAMP in rat SC basal media for 72 h to induce differentiation into myelinating SCs, followed by dbcAMP withdrawal to reprogram into repair SCs. Conditioned culture media was used to extract small extracellular vesicles. Total RNA was extracted from cell lysates and EV samples and then sequenced for mRNA, miRNA, and lncRNA.