Fig. 3.

Histochemical and DAB immunohistochemical stainings. a Hematoxylin & eosin (HE) staining shows fiber size variation and internal nuclei, multiple cytoplasmic inclusions are present showing sarcoplasmic and subsarcolemmal localization (arrows). b, c Rimmed vacuoles (arrows) are observed in HE (b) and immunostaining for the autophagosome marker LC3b (c). d In Gomori’s trichrome, sarcoplasmic inclusions show red labeling. e, f Enzyme histochemical COX-SDH e and mitochondrial NADH diaforase f stainings show small irregular sarcoplasmic areas of reduced activity. g Myofibrillar protein accumulation as shown by myotilin staining is present in several fibers in DAB immunostaining, whereas desmin h does not accumulate in a similar manner. i–l In p62/SQSTM1, ubiquitin and SMI-31 stainings, multiple positive protein inclusions and punctate labeling are observed in nearly all fibers, whereas TDP-43 staining remains negative. Panels f–l are serial sections. Scale bars = 100 µm