An in vitro model to study inhibition of axon regeneration from DRGs neurons mediated by Guillain Barrè Syndrome-associated anti-glycan antibodies.;

ROZÉS SALVADOR, V.; HEREDIA, F.; WOJNACKI, J. ; PALANDRI, A. ; CACERES, A; LOPEZ, P.H.H.

Maitencillo

Workshop; Emerging Concepts on Neuronal Cytoskeleton; 2013

CENEDYN

Axon regeneration is a response of injured nerve cells that is critical for the restoration of structure and function after PNS or CNS injuries; this response is key to recover from numerous neurological disorders like acute immune neuropathy called Guillain Barré Syndrome (GBS). Some clinical studies associate the presence of anti-ganglioside antibodies (anti-Gg abs) with poor recovery in GBS. Patients with incomplete recovery have impaired nerve repair. It was recently demonstrated in a passive transfer animal model that an anti-Gg mAb (GD1a/GT1b, clone 1B7) can halt axon regeneration. Defining the signaling pathways that prevent regeneration of injured axons can provide key insights to allow development of therapeutic approaches to enhance axon growth. We developed an in vitro model of axon regeneration using organotypic co-cultures of dorsal root ganglion explants with peripheral nerve. We observed a ganglioside-dependent inhibition of axon regeneration associated with the presence of end-bulb like structures characteristic of dystrophic growth cones when treating nerves with mAb 1B7. Also, treatment of dissociated DRGn cultures with mAb 1B7 induced reorganization of components of the growth cone cytoskeleton. In addition DRGn were nucleofected with LifeAct-mCherry and tubulin-GFP and subject to time-lapse microscopy. We observed that treatment with mAb 1B7 induced a rapid loss of actin filopodia. Overall our in vitro models gave us a useful tool to characterize anti-Gg Ab-induced dystrophic growth cones. Finally this data will provide knowledge about the molecular mechanisms determining impaired nerve repair in GBS which could suggest new pharmacological targets for promoting axon regeneration.