title: Anti-glycan antibodies halt axon regeneration in a model of Guillain Barrè Syndrome axonal neuropathy by inducing microtubule disorganization via RhoA-ROCK-dependent inactivation of CRMP-2.
abstract: Several reports have linked the presence of high titers of anti-Gg Abs with delayed recovery/poor prognosis in GBS. In most cases, failure to recover is associated with halted/deficient axon regeneration. Previous work identified that monoclonal and patient-derived anti-Gg Abs can act as inhibitory factors in an animal model of axon regeneration. Further studies using primary dorsal root ganglion neuron (DRGn) cultures demonstrated that anti-Gg Abs can inhibit neurite outgrowth by targeting gangliosides via activation of the small GTPase RhoA and its associated kinase (ROCK), a signaling pathway common to other established inhibitors of axon regeneration. We aimed to study the molecular basis of the inhibitory effect of anti-Gg abs on neurite outgrowth by dissecting the molecular dynamics of growth cones (GC) cytoskeleton in relation to the spatial-temporal analysis of RhoA activity. We now report that axon growth inhibition in DRGn induced by a well characterized mAb targeting gangliosides GD1a/GT1b involves: i) an early RhoA/ROCK-independent collapse of lamellipodia; ii) a RhoA/ROCK-dependent shrinking of filopodia; and iii) alteration of GC microtubule organization/and presumably dynamics via RhoA/ROCK-dependent phosphorylation of CRMP-2 at threonine 555. Our results also show that mAb 1B7 inhibits peripheral axon regeneration in an animal model via phosphorylation/inactivation of CRMP-2 at threonine 555. Overall, our data may help to explain the molecular mechanisms underlying impaired nerve repair in GBS. Future work should define RhoA-independent pathway/s and effectors regulating actin cytoskeleton, thus providing an opportunity for the design of a successful therapy to guarantee an efficient target reinnervation.
authors.affiliation: Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina.
authors.forename: Victoria
authors.initials: V
authors.lastname: Rozés Salvador
authors.affiliation: Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina.
authors.forename: Florencia
authors.initials: F
authors.lastname: Heredia
authors.affiliation: Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina.
authors.forename: Andrés
authors.initials: A
authors.lastname: Berardo
authors.affiliation: Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina.
authors.forename: Anabela
authors.initials: A
authors.lastname: Palandri
authors.affiliation: Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina.
authors.forename: Jose
authors.initials: J
authors.lastname: Wojnacki
authors.affiliation: Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina.
authors.forename: Ana L
authors.initials: AL
authors.lastname: Vivinetto
authors.affiliation: Department of Neurology, University of Texas Medical School at Houston, Houston, USA.
authors.forename: Kazim A
authors.initials: KA
authors.lastname: Sheikh
authors.affiliation: Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Caceres
authors.affiliation: Laboratory of Neurobiology, Instituto de Investigación Médica Mercedes y Martin Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Argentina; Facultad de Psicología, Universidad Nacional de Córdoba, Argentina. Electronic address: phhlopez@immf.uncor.edu.
authors.forename: Pablo H H
authors.initials: PH
authors.lastname: Lopez
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000906:Antibodies / Q000494:pharmacology*; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005727:Ganglia, Spinal / Q000166:cytology; D005786:Gene Expression Regulation / Q000187:drug effects; D036341:Intercellular Signaling Peptides and Proteins; D008870:Microtubules / Q000187:drug effects / Q000473:pathology*; D009416:Nerve Regeneration / Q000187:drug effects* / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D016501:Neurites / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D011134:Polysaccharides / Q000276:immunology*; D051381:Rats; D017208:Rats, Wistar; D020426:Sciatic Neuropathy / Q000378:metabolism / Q000473:pathology; D015398:Signal Transduction; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*
chemical_list: D000906:Antibodies; D004791:Enzyme Inhibitors; D036341:Intercellular Signaling Peptides and Proteins; D009419:Nerve Tissue Proteins; D011134:Polysaccharides; C095114:collapsin response mediator protein-2; D020742:rhoA GTP-Binding Protein
keywords: Anti-glycan antibodies; Axon regeneration; Ganglioside; Guillain Barrè Syndrome; Nerve repair; Peripheral nerve; RhoA GTPase