Immunohistochemical demonstration of spinal ventral horn cells involvement in a case of "myoclonus epilepsy with ragged red fibers" (MERRF).
OBJECTIVE
To detect mitochondrial lesions in the spinal cord from an autoptic case of myoclonus epilepsy with ragged-red fibers (MERRF) that harbored the A8344G mutation and was deemed to be free of pathological abnormalities in the spinal cord after conventional post-mortem examination.


METHODS
Antibodies against subunits of complex III and IV of the respiratory chain were used to perform immunohistochemical analysis on cervical, thoracic and lumbar sections of the spinal cord from the case of MERRF and from controls. Immunostaining was carried out by the avidin-biotin peroxidase complex (ABC) method.


RESULTS
A selective decreased expression of subunit II of cytochrome c oxidase (COX-II) was found in all spinal cord sections from the patient.


CONCLUSIONS
The immunohistochemical demonstration of mitochondrial lesions in the spinal ventral horn cells from this case with MERRF seems to be consistent with the results of many genetic studies pointing to a high and homogeneous distribution of mutant mtDNA in different neuronal populations of patients with this disease. The use of these immunological probes in the study of mitochondrial encephalomyopathies can increase both the resolution and the specificity of morphological observations in the central nervous system (CNS).
U.O. di Neurologia e Neuroriabilitazione, Ospedale S. Maria del Carmine, Rovereto, Italy.
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Rizzuto
D000328:Adult; D000870:Anterior Horn Cells / Q000473:pathology*; D000911:Antibodies, Monoclonal; D004272:DNA, Mitochondrial / Q000235:genetics; D003576:Electron Transport Complex IV / Q000378:metabolism; D004831:Epilepsies, Myoclonic / Q000235:genetics / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009154:Mutation / Q000235:genetics; D009412:Nerve Fibers / Q000473:pathology*; D013116:Spinal Cord / Q000473:pathology
D000911:Antibodies, Monoclonal; D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV