title: [Axonal regeneration in spinal cord injury: key role of galectin-1].
abstract: When spinal cord injury (SCI) occurs, a great number of inhibitors of axonal regeneration consecutively invade the injured site. The first protein to reach the lesion is known as semaphorin 3A (Sema3A), which serves as a powerful inhibitor of axonal regeneration. Mechanistically binding of Sem3A to the neuronal receptor complex neuropilin-1 (NRP-1) / PlexinA4 prevents axonal regeneration. In this special article we review the effects of galectin-1 (Gal-1), an endogenous glycan-binding protein, abundantly present at inflammation and injury sites. Notably, Gal1 adheres selectively to the NRP-1/PlexinA4 receptor complex in injured neurons through glycan-dependent mechanisms, interrupts the Sema3A pathway and contributes to axonal regeneration and locomotor recovery after SCI. While both the monomeric and dimeric forms of Gal-1 contribute to "switch-off" classically-activated microglia, only dimeric Gal-1 binds to the NRP-1/PlexinA4 receptor complex and promotes axonal regeneration. Thus, dimeric Gal-1 promotes functional recovery of spinal lesions by interfering with inhibitory signals triggered by Sema3A adhering to the NRP-1/PlexinA4 complex, supporting the use of dimeric Gal-1 for the treatment of SCI patients.
authors.affiliation: Instituto de Química y Físico Química Biológica, Facultad de Farmacia y Bioquímica, UBA. E-mail: quintaramiro@hotmail.com.
authors.forename: Héctor R
authors.initials: HR
authors.lastname: Quintá
authors.forename: Juana M
authors.initials: JM
authors.lastname: Pasquini
authors.forename: Gabriel A
authors.initials: GA
authors.lastname: Rabinovich
authors.forename: Laura A
authors.initials: LA
authors.lastname: Pasquini
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology*; D037483:Galectin 1 / Q000502:physiology*; D006801:Humans; D051379:Mice; D017628:Microglia / Q000378:metabolism; D009416:Nerve Regeneration / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000378:metabolism; D039942:Neuropilin-1 / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism; D040121:Semaphorin-3A / Q000502:physiology; D013119:Spinal Cord Injuries / Q000503:physiopathology*
chemical_list: D037483:Galectin 1; D009419:Nerve Tissue Proteins; C492110:Plxna4 protein, mouse; D011956:Receptors, Cell Surface; D040121:Semaphorin-3A; D039942:Neuropilin-1
keywords: galectin-1; neuropilin-1; semaphorin 3A; spinal cord injury