Research Paper Volume 12, Issue 14 pp 13939—13957

Both ghrelin deletion and unacylated ghrelin overexpression preserve muscles in aging mice

Figure 5. Metabolic shift in TA muscles of WT, Tg, and Ghrl KO mice. (A) Representative images of succinate dehydrogenase (SDH) staining (scale bars: 200 μm) representing the oxidative capacity of TA muscles of 3-month old (young) and 24-month old (old) mice and quantification of SDH-positive fibers in TA muscle presented as the percentage of SDH-positive area above the total muscle surface. Young mice: WT= 5, Tg= 4, Ghrl KO= 5; old mice: WT= 4, Tg= 3, Ghrl KO= 5. (B) Representative Western blots images and protein densitometry quantification for mitochondrial transcription factor A (TFAM), ATP-synthase β-subunit (β-ATPase), succinate-dehydrogenase complex subunit-A (SDHA), peroxisome proliferator-activated receptor gamma (PPARγ), and PPARγ-coactivator-1-α (PGC1α) protein levels. Protein levels were probed in gastrocnemii of old mice, WT= 4, Tg= 5, Ghrl KO= 5. (C) Representative images of cytochrome c oxidase subunit 4 (COX4) immunofluorescence (scale bars: 200 μm) and quantification. Young mice: WT = 3, Tg = 3, Ghrl KO = 3; old mice: WT = 4, Tg = 4, Ghrl KO = 4. Data are presented as mean ± SEM. *p<0.05 and **p<0.01, old vs. young; $p<0.05 and $$p<0.01, Tg and Ghrl KO vs. WT.