FIGURE 7.

Aggresome formation and composition in 8-month-old mice. To detect protein aggregates, FDB fibers (A) were treated with either vehicle or 5 μM MG132 overnight before being fixed, permeabilized and stained with Proteostat aggresome detection reagent. White boxes indicate regions that were expanded in the lower panel. White scale bars are 50 μm, yellow scale bars in expanded images are 25 μm. Arrows indicate examples of features that were quantified. Red puncta indicate aggresome formation and were quantified (B) in multiple fibers from five WT and five DG mice. Each symbol represents a single fiber. Proteostat composition was assessed by co-staining with Proteostat reagent and antibodies to (C, D) CASQ, (E) polyubiquitin and (F) p62 Scale bars are 10μm. G, Polyubiquitin immunofluorescence staining in EDL muscle sections from WT and DG mice. Scale bars are 50 μm. Representative western blot (H) and quantitation (I) of ubiquitination and p62 in EDL muscle homogenates. Each symbol in (I) represents a single muscle taken from an individual mouse. Statistical significance is indicated by *(P < .05) and **(P < .005)