title: Schwann cell-derived exosomes enhance axonal regeneration in the peripheral nervous system.
abstract: Axonal regeneration in the peripheral nervous system is greatly supported by Schwann cells (SCs). After nerve injury, SCs dedifferentiate to a progenitor-like state and efficiently guide axons to their original target tissues. Contact and soluble factors participate in the crosstalk between SCs and axons during axonal regeneration. Here we show that dedifferentiated SCs secrete nano-vesicles known as exosomes which are specifically internalized by axons. Surprisingly, SC-derived exosomes markedly increase axonal regeneration in vitro and enhance regeneration after sciatic nerve injury in vivo. Exosomes shift the growth cone morphology to a pro-regenerating phenotype and decrease the activity of the GTPase RhoA, involved in growth cone collapse and axon retraction. Altogether, our work identifies a novel mechanism by which SCs communicate with neighboring axons during regenerative processes. We propose that SC exosomes represent an important mechanism by which these cells locally support axonal maintenance and regeneration after nerve damage.
authors.affiliation: Millennium Nucleus for Regenerative Biology, Faculty of Biological Sciences, Pontificia Universidad Catolica de Chile, Santiago, Chile.
authors.forename: María Alejandra
authors.initials: MA
authors.lastname: Lopez-Verrilli
authors.forename: Frederic
authors.initials: F
authors.lastname: Picou
authors.forename: Felipe A
authors.initials: FA
authors.lastname: Court
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism* / Q000473:pathology; D002478:Cells, Cultured; D055354:Exosomes / Q000378:metabolism*; D008297:Male; D009416:Nerve Regeneration / Q000502:physiology*; D059348:Peripheral Nerve Injuries / Q000378:metabolism* / Q000473:pathology; D010525:Peripheral Nerves / Q000378:metabolism / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012583:Schwann Cells / Q000378:metabolism*
keywords: Schwann cell; axonal regeneration; exosomes; nerve injury