Pathological changes within two weeks following spinal cord injury in a canine model.

PURPOSES: This study aimed to investigate the histopathological changes that occur within 2 weeks following spinal cord injury (SCI) in dogs. METHODS: Eight adult female Beagle dogs were included in this study, and SCI was induced using an epidural balloon catheter. Two dogs were killed at each of the following four time points: immediately after the procedure and 1 day, 1 week, and 2 weeks after the procedure. Neurological status was evaluated with five categories. Histopathological changes were visually observed for stained sections of formalin-fixed spinal cord to evaluate hemorrhage, spongiosis, necrosis, and gliosis morphologically. RESULTS: Along the 2 weeks post-injury, severe hemorrhage was observed at the primary injury site, the average diameter of which expanded quickly from 8 to 10 mm in 1 day and then decreased to 5 mm in 1 week. This indicates that the bleeding cavity expanded at the initial injury site to produce ascending and descending hemorrhage. The hemorrhage at the injury site resolved in 2 weeks. In contrast, spongiosis, parenchymal necrosis, and gliosis were first inconspicuous or mild and then became severe in 1 week or 2 weeks. Hemorrhage, hematoma, and other similar changes occurred at the regions approximately 20-mm rostral and caudal to the primary injury site. These changes were observed in both gray matter and white matter. CONCLUSIONS: This study is the first to assess the sequential histopathological changes in the acute and intermediate phases following SCI in dogs. Our findings enhance the usefulness of the canine intervertebral disk disease model in the assessment of secondary spinal cord histopathology in human SCI.

A novel mutation at position +11 in the intron following exon 10 of the tau gene in FTDP-17.

Mutations in the microtubule-associated tau gene are responsible for frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17). A reduced ability of the mutated microtubule-associated tau protein to interact with microtubules causes microtubule destabilization leading to deleterious effects on axonal transport and the formation of tau filaments. Here, we describe a new mutation of the tau gene, a T --> C transition at position +11 of the intron following exon 10 (T --> C 3'E10 +11) in the family showing frontotemporal dementia with very early age of onset (the first decade of proband's life). The T -->C 3'E10 +11 mutation caused a large increase in the proportion of transcripts containing exon 10 detected by exon-trapping analysis. Our study confirmed that the T --> C 3'E10 +11 mutation, as the other 5' splice site mutations of tau exon 10, modifies alternative splicing of exon 10.

Immunoreactivity of valosin-containing protein in sporadic amyotrophic lateral sclerosis and in a case of its novel mutant.

BACKGROUND: Mutations in the valosin-containing protein (VCP) gene were first found to cause inclusion- body myopathy with early-onset Paget disease and frontotemporal dementia (IBMPFD). Mutations in the VCP gene were later reported to occur in familial amyotrophic lateral sclerosis (ALS). But the role of VCP in the neurodegenerative processes that occur in ALS remains unknown. The purpose of the present study was to elucidate the role of VCP in the neurodegeneration seen in sporadic and VCP mutant ALS. RESULTS: Immunohistochemistry demonstrated that the frequency of distinct VCP-positive nuclei of spinal motor neurons of patients with sporadic ALS (SALS) and the ALS with VCP novel mutation (ALS-VCP, M158V) was increased, compared with that of the control cases. No VCP-positive inclusion bodies were observed in SALS patients, a ALS-VCP patient or in control subjects. Neuropathologic examination of the ALS-VCP case showed loss of motor neurons, the presence of Bunina bodies, and degeneration of the corticospinal tracts. Bunina bodies detected in this case were confirmed to show immunohistochemical and ultrastructural features similar to those previously described. Furthermore, neuronal intracytoplasmic inclusions immunopositive for TAR DNA-binding protein 43 kDa (TDP-43), phosphorylated TDP-43, ubiquitin (Ub), p62, and optineurin were identified in the spinal and medullary motoneurons, but not in the neocortex. Gene analysis of this ALS-VCP patient confirmed the de novo mutation of M158V, which was not found in control cases; and bioinformatics using several in silico analyses showed possible damage to the structure of VCP. Immunocytochemical study of cultured cells showed increased cytoplasmic translocation of TDP-43 in cells transfected with several mutant VCP including our patient's compared with wild-type VCP. CONCLUSION: These findings support the idea that VCP is associated with the pathomechanism of SALS and familial ALS with a VCP mutation, presumably acting through a dominant-negative mechanism.

Differential expression between synaptic vesicle proteins and presynaptic plasma membrane proteins in the anterior horn of amyotrophic lateral sclerosis.

This study concerns the immunohistochemical investigation of synaptic proteins in the anterior horn of amyotrophic lateral sclerosis (ALS). Antibodies against synapsin 1 and synaptophysin (i.e. synaptic vesicle proteins), and those against syntaxin and the synaptosomal-associated, 25 kDa protein, SNAP25 (i.e. presynaptic plasma membrane proteins) were used for immunostaining, respectively. Lumbar spinal cords from five ALS and eight control patients were examined. In the controls, all four synaptic proteins exhibited fine granular immunoreactivities, distributed throughout the spinal gray matter almost uniformly. In contrast, in all five ALS patients, two of the synaptic vesicle proteins examined decreased in the anterior horn neuropil diffusely, while in the same lumbar segments of these cases the immunoreactivities of the two presynaptic plasma membrane proteins showed no apparent decrease, or were only mildly diminished in the same gray matter area. These results indicate that, during the presynaptic terminal degeneration in the anterior horn of ALS, synaptic vesicle involvement may precede that of the presynaptic plasma membrane.