Fig. 4

Cystatin F is necessary for remyelination following JHMV-induced demyelination. (A) Cst7^−/− mice and littermate controls were i.c. infected with JHMV, and spinal cords were isolated at days 14 and 21 p.i. (B) Representative images showing increased SMI32 staining in spinal cords of JHMV-infected Cst7-/- mice compared to control mice; upper panels display DAPI (blue), fluoromyelin (green), and SMI32 (red); lower panels show only SMI32 staining at day 21 p.i. (C) Quantification of SMI32 staining in Cst7-/- mice (n = 7) and control mice (n = 7). (D) Representative spinal cord tissue stained with H&E and LFB (stains myelin fibers blue) from infected Cst7-/- and control mice at day 21 p.i., revealing demyelination within the ventral funiculus and lateral white matter columns (outlined by black line). Quantification of spinal cord demyelination at (E) day 14 p.i. (n = 4, control; n = 6, Cst7-/-) and (F) day 21 p.i. (n = 15, control; n = 12, Cst7-/-) between control and Cst7-/- mice. (G) Electron micrographs showing ultrathin spinal cord sections from control and Cst7-/- mice at day 21 p.i. highlighting myelinated, demyelinated, remyelinated axons and degenerated axons. Histological comparisons in the ventral funiculus and lateral white matter columns between Cst7-/- mice (n = 6) and controls (n = 6) were made from electron micrographs, including (H) ratios of myelinated, demyelinated axons, and remyelinated axons calculations, and (I) g-ratios (axon diameter/total fiber diameter), Scale bar for F is 2 μm. For H and I, 133–660 axons were analyzed per mouse. For SMI-32 analysis, data represents mean ± SD. All other data represent the mean ± SEM; *p < 0.05, **p < 0.01, ***p < 0.001