Guillain Barré Syndrome-associated anti-glycan antibodies alter growth cone cytoskeleton from growing DRGs neurons.

ROZÉS SALVADOR, V.; HEREDIA, F.; WOJNACKI, J. ; PALANDRI, A. ; CACERES, A; LOPEZ, P.H.H.; ROZÉS SALVADOR, V.1; WOJNACKI, J. 1; HEREDIA, F.1 ; PALANDRI, A. 1; SHEIKH, KAZIN A.3; CACERES, A1; LOPEZ, P.H.H.1,2

Puerto Varas, Chile

Workshop; EMBO Emerging Concepts of the Neuronal Cytoskeleton Workshop; 2015

EMBO

Axon regeneration is a response of injured nerve cells critical for the nerve repair in human acute immune neuropathies such as Guillain Barré Syndrome (GBS). Clinical studies associate the presence of anti-ganglioside antibodies (anti-Gg abs) with poor recovery in GBS. Passive transfer of mAb (GD1a/GT1b, clone 1B7) or patient-derived anti-Gg Abs in an animal model halts axon regeneration. The aim of this work is to study the molecular bases of axonal regeneration inhibition produced by anti-Gg Abs. Two in vitro models were developed including co-cultures of dorsal root ganglion (DRG) explants with peripheral nerve and culture of primary dissociated DRG neuron (DRGn) where the inhibitory effect of mAb 1B7 was confirmed. Fluorescent-tagged cytoskeleton components were used to study their dynamics at growth cones (GC) by time-lapse video microscopy together with immunofluorescence analysis of microtubules. Studies of 1B7-triggered signaling events included measurement of RhoA GTPasa activity using a FRET-based biosensor and activity of its downstream target Collapsin-Response-Mediator Protein-2 (CRMP-2) by phospho-specific mutants and western blot.1B7-treated explants showed a ganglioside-dependent inhibition of axon regeneration associated with the presence of dysthrophic GC. Also, 1B7 treatment induced a RhoA/ROCK-dependent collapse of tubulin cytoskeleton via inactivation of CRMP-2 at T-555.Overall, our data provide knowledge about the mechanisms determining impaired nerve repair.