title: Delayed applications of L1 and chondroitinase ABC promote recovery after spinal cord injury.
abstract: The inhibitory environment of the injured spinal cord is an obstacle to functional recovery and axonal regeneration in adult mammals. We had previously shown that injection of adeno-associated virus (AAV) encoding the L1 cell adhesion molecule (AAV-L1) at the time of acute thoracic compression injury of adult mice promotes locomotor recovery, which is associated with ameliorated astrogliosis and improved axonal regeneration in the lumbar spinal cord. In the present study, we investigated whether delayed injection of AAV-L1, chondroitinase ABC (Chase), or the combination of the two agents into the mouse spinal cord 3 weeks after injury would also lead to improved recovery. The Basso Mouse Scale showed enhanced locomotor recovery 12 weeks after application of the agents in all treatment groups compared to the control group that was injected with AAV encoding green fluorescent protein (AAV-GFP). Investigation of hindlimb function using single-frame motion analysis revealed, however, that L1 overexpression, but not injection of Chase, improved voluntary movements without body weight support, whereas injection of Chase, but not L1 overexpression, enhanced body weight support during stepping. Mice with the combined application of AAV-L1 and Chase showed improvement in both parameters. Enhanced motor recovery after combined application correlated with increased densities of cholinergic and GABAergic terminals at motoneuronal cell bodies, and of lamina-specific glutamatergic sensory afferents 15 weeks after injury, indicating enhanced synaptic rearrangements in the lumbar spinal cord below the lesion site. These findings suggest that L1 overexpression combined with Chase application may contribute to the treatment of sub-chronic spinal cord injury.
authors.affiliation: Zentrum für Molekulare Neurobiologie, University Hospital Hamburg-Eppendorf, University of Hamburg, Hamburg, Germany.
authors.forename: Hyun Joon
authors.initials: HJ
authors.lastname: Lee
authors.forename: Shan
authors.initials: S
authors.lastname: Bian
authors.forename: Igor
authors.initials: I
authors.lastname: Jakovcevski
authors.forename: Bin
authors.initials: B
authors.lastname: Wu
authors.forename: Andrey
authors.initials: A
authors.lastname: Irintchev
authors.forename: Melitta
authors.initials: M
authors.lastname: Schachner
mesh_terms: D000818:Animals; D019765:Chondroitin ABC Lyase / Q000494:pharmacology* / Q000627:therapeutic use; D004195:Disease Models, Animal; D004334:Drug Administration Schedule; D005260:Female; D015316:Genetic Therapy / Q000379:methods; D051379:Mice; D008810:Mice, Inbred C57BL; D009416:Nerve Regeneration / Q000187:drug effects / Q000235:genetics; D039842:Neural Cell Adhesion Molecule L1 / Q000235:genetics*; D020127:Recovery of Function / Q000187:drug effects / Q000235:genetics; D013119:Spinal Cord Injuries / Q000188:drug therapy* / Q000201:enzymology / Q000503:physiopathology*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D039842:Neural Cell Adhesion Molecule L1; D019765:Chondroitin ABC Lyase