Elucidation of the mechanisms involved in the regeneration of Oligodendrocytes and ReMyelination is a central issue in Multiple Sclerosis (MS) research.
We recently identified a novel alternatively spliced, developmentally regulated Oligodendrocyte-specific protein designated MicroTubule-Associated Protein-2+13 [MicroTubule-Associated Protein-2 expressing exon 13 (MAP-2+13)].
MAP-2+13 is expressed in human fetal Oligodendrocytes during process extension and Myelination but is minimally expressed in normal mature CNS.
To test the hypothesis that MAP-2+13 is re-expressed in regenerating Oligodendrocytes in MS Lesions, we examined the Brains of MS patients for the expression of this protein.
By ImmunoCytoChemistry using a series of MonoClonal AntiBodies specific for MAP-2+13, we determined that MAP-2+13 expression was up-regulated in all 31 lesions from 10 different MS Brains.
MAP-2+13 was expressed in regenerating Oligodendrocytes associated with DeMyelinated lesions, with the highest counts found in regions of extensive ReMyelination.
By electron microscopy, MAP-2+13 was localized to Oligodendrocytes engaged in ReMyelination, evident by their Process extension and association with Thinly Myelinated (ReMyelinated) and DeMyelinated Axons.
These results suggest a hitherto unsuspected role for this MicroTubule-Associated Protein in Oligodendrocyte function during development and Myelin repair.