Additional file 18 of The double homeodomain protein DUX4c is associated with regenerating muscle fibers and RNA-binding proteins

Additional file 18: Figure S17. Myosin and macrophages detection in FSHD muscles. (A) Detection of slow and fast myosin. Immunofluorescence was performed on muscle sections with specific mAbs for slow and fast myosin (as described in Methods). In healthy control muscles, slow- and fast-twitch fibers present similar diameters. In the FSHD affected muscle analyzed, many slow fibers are atrophic (arrow) or necrotic (arrowhead). Ghost fibers or adipocytes are detected by their lack of myosin labeling (stars). (B) Co-immunofluorescence labeling of macrophage CD206/CD68 markers and laminin-α2 in affected muscles. Nuclei are labeled with DAPI. Few CD68+ (pro-inflammatory M1 macrophages) cells are observed (white arrows, upper panel). CD68+/CD206+ cells corresponding to M2 macrophages (yellow arrows) are much more frequent in the analyzed FSHD muscles (n=5). All macrophages observed inside FSHD muscle fibers are of M2 type (star, bottom panel). The histogram represents the percentage of M1 and M2 macrophages evaluated by counting CD68+/CD206- and CD68+/CD206+ cells on 10 microscopic fields.