Rol modulatorio de MAG en la sobrevida de motoneuronas.

ANABELA PALANDRI; PABLO HECTOR HORACIO LOPEZ

Córdoba

Encuentro; Segundo Encuentro de Jóvenes Investigadores de Neurociencias de Córdoba; 2012

Jóvenes Investigadores de Neurociencias

Myelin associated glycoprotein (MAG) is a lectin present in the periaxonal layer of myelin that engages several axonal receptors, including Nogo-receptors (NgRs), to mediate its biological functions. It has been proposed that NgRs have a modulatory rol on programmed cell death (PCD) of motoneurons (MNs) dependent of the neurotrophin receptor P75NTR. The aim of this study was to analyze a possible modulatory role of MAG on PCD of MNs. A time course study showed that early after birth Mag-null mice have a reduction in MN count. Also Mag-null mice exhibit increased susceptibility in an in vivo model of PCD induced by a sciatic nerve crush. Interestingly pre-treatment with a soluble form of MAG (MAG-Fc) prevented MN apoptosis in this model. Studies using an in vitro model of P75NTR-dependent PCD on spinal cord organotypic cultures confirmed the protective role of MAG. Similarly MAG-Fc exerted a protective effect against PCD when tested in a MN-derived cell line with, opening the opportunity to study the signaling pathway associated with this effect. Overall these results demonstrate a new role for MAG as protecting MNs from PCD. These results expand our knowledge of the nurture role of myelination on axons and at the same time open new possibilities