Fig. 5.

Myt1 expression in multiple sclerosis (MS) and control cases. Representative results are shown from adult human brain sections that were immunostained for Myt1 (A–C), processed for in situ hybridization for Myt1 mRNA (D), or analyzed by immunostaining for Myt1 combined with in situ hybridization for proteolipid protein (PLP) mRNA as a marker of oligodendrocytes (E,F). Nuclear immunostaining for Myt1 (brown DAB with pink eosin tissue counter stain) was seen in small round cells in the periplaque white matter (PPWM) adjacent to MS lesions (A, PPWM; case 9, Table 1), at an increased density relative to white matter control areas (B; case 2, Table 1). In some MS lesions (C, lesion area; case 6, Table 1), reactive astrocytes exhibited cytoplasmic immunoreactivity for Myt1 (brown DAB with pink eosin tissue counter stain), which was never seen in control cases. In situ hybridization for Myt1 mRNA (D, lesion edge; dark blue; case 4, Table 1) in MS lesions indicated expression of Myt1 in a pattern similar to Myt1 immunoreactivity (A). Within MS lesions, some cells with nuclear Myt1 expressed PLP mRNA transcripts (E, lesion; Myt1 brown, PLP dark blue; case 10, Table 1). Co-labeling for Myt1 among oligodendrocytes expressing PLP mRNA was generally not observed in adult human control white matter (F; case 3, Table 1). Scale bars = 50 µm for (A–F), as shown in (F). (A–F) Arrows indicate examples of cells expressing Myt1 protein (A–C,E) or mRNA transcripts (D). Arrowheads (B,E,F) indicate examples of cells that are not expressing Myt1.