Figure 3
From: The histone deacetylase SIRT6 blocks myostatin expression and development of muscle atrophy
SIRT6 depletion exhibits sarcomeric and mitochondrial deficiencies and up-regulation of factors of muscle degradation pathways. (A) MuRF1 mRNA expression was determined by qPCR in Null-adv.-infected and T6KD-cardiomyocytes. (B) WT and SIRT6-KO heart lysates were immunoblotted with MuRF1, LC3B and SIRT6 antibodies. A non-specific protein band (NS) used as a loading control. (C) Quantitation for MuRF1 protein levels in the heart. Data represented as mean ± SEM for 3–5 samples, *p < 0.05. (D–H) Representative transmission electron micrographs showing structural integrity of sarcomeres and mitochondria in WT and SIRT6-KO hearts. WT heart section (D) shows normal organization of sarcomeres with rows of uniformly dense mitochondria, while SIRT6-KO hearts show (E) distorted myofibrils in focal areas (elbow arrow connecter), electron-dense lysosomes (black-bordered white arrows), (F,G right two panels) degenerating mitochondria with reduced electron-dense or vacuolated matrix (black arrowheads) compared to (G, left panel) WT and (H) accumulation of autophagy-vacuoles (arrows). Scale Bars are as indicated.
