Figure 5. IKK2 muscle depletion protects fiber size and maintains fiber type.

(A and B) Representative images of H&E-stained atrophied muscle 28 days after denervation. Note the absence of angular atrophic fibers and the nuclear accumulation in Ikk2^mko denervated muscles (C) Histogram (frequency distribution of fiber CSA) shows the maintenance of fiber size in Ikk2^mko gastrocnemius (white bars) compared with the control atrophied muscles (black bars). (D and E) Representative images of NADH staining that mark slow fibers with dark blue (red arrows) and intermediate fibers with light blue (purple arrows). (F) Fiber-type distribution in denervated soleus muscles: 37.5% decrease in slow fibers in control muscles, which become intermediate. Note the maintenance of fiber-type distribution in Ikk2^mko denervated soleus.