Figure 4. BAG3^Ile81 rescues ischemic BALB/c muscle morphology and regeneration.

BL6 (black bars) and BALB/c (gray bars) mice injected IM with AAVs were subjected to HLI for 7 days. The TA was analyzed histologically (H&E, A, scale bar=100μm), and non-myofiber area (B) and myofiber cross sectional area (C) were quantified (N≥5 mice/group). Note the lack of fascicular myofiber arrangement and absence of centralized myofiber nuclei in GFP and BAG3^Met81 groups, which were rescued by BAG3^Met81. D. Representative immunofluorescence images of TA muscle labeled with antibodies against embryonic heavy chain (eMyHC) and dystrophin (pseudocolored green scale bar=100μm) were used to quantify eMyHC⁺ myofiber number (E) and size (F) (N≥5 mice/group). There were very few eMyHC⁺ fibers in contralateral non-ischemic control limbs. G–H. Gastrocnemius mRNA expression of myogenin (G) and Tmem8c (myomaker) (H) were determined by qRT-PCR (N≥5 mice/group, corrected for GAPDH and normalized to contralateral control). I. Representative images of primary muscle progenitor cells from BALB/c mice that were infected with AAVs encoding GFP, BAG3^Met81, or BAG3^Ile81 then differentiated into myotubes and labeled with DAPI and anti-MyHC (N≥3 group). J. Quantification of myoblast fusion index. K. Quantification of fusion index for C3H-10T1/2 pluripotent pericyte cells and C2C12 myoblasts mixed at a 75:25 ratio and infected with the indicated AAVs (N≥3 group). *P<0.05 vs. Control; †P<0.05 vs. BL6; ‡ P<0.05 vs. GFP or BAG3^Met81. All data are means ± SEM.