Figure 4

Muscle fiber atrophy in C26-bearing mice. a) Esterase staining of TA cross-sections from control (left) and tumor-bearing (right) mice, three weeks following transplant. Fiber atrophy is evident in different fiber types in the absence of lysosome accumulation. The intensely stained neuromuscular junctions are also visible. Bar = 50 μm. b) NADH-transferase staining can be used to differentially analyze larger, glycolytic fibers (arrow) and smaller, oxidative fibers (arrowhead), in TA cross-sections from control (top) and tumor-bearing (bottom) mice. Intermediate fibers are also visible. The fiber cross-sectional area (CSA) was measured, and the distribution is shown for both glycolytic and slow fibers, in control (black bars) and C26-bearing (gray bars) mice. The average size ± SEM of each fiber size class calculated from replicate experiments is shown, along with the medians of each distribution. C26-induced fiber atrophy is detectable in both fiber types. c) Immunostaining for laminin (green) on TA cross-sections from control (left) and tumor-bearing (right) mice, three weeks following transplant, showing alterations in the basement membrane. Bar = 100 μm. d) Immunostaining for laminin (red) performed on enzymatically isolated fibers, obtained from EDL of control (left) and tumor-bearing (right) mice, and longitudinally depicted by confocal microscopy. Nuclei are counterstained with TO-PRO and pseudo-colored in blue. Bar = 30 μm.