Fig 1: The presence of PMAT induces muscle senescence and up-regulates FoxO-Atrogin1/Murf1 signaling.(A) Relative transcript levels of senescence-related genes (p16, p19, p21 and p57) and Atrogin1 Murf1 in skeletal muscle of mice transplanted with ND or HFD iWAT (n = 6 per group). (B) Representative western blot images of phosphorylated FoxO3 and FoxO1 protein in the cytoplasm (left panel) and corresponding total protein in the nucleus (right top panel) of skeletal muscle from mice transplanted with ND or HFD iWAT. Corresponding quantification of total FoxO3 and FoxO1 protein in the nucleus (right bottom panel) (n = 3 per group). Hsc70 or Histone staining served as internal loading controls. (C) Representative images (left panels) and quantification (right panels) of the number of nuclear FoxO1- or FoxO3-positive cells in skeletal muscle from mice transplanted with ND or HFD iWAT. (D) Representative images (top panels) and quantified diameters (bottom panel) of differentiated C2C12 myotubes after PAI-1 and dexamethasone (Dex) treatment. (E) Relative expression of cellular senescence-related transcripts (p21, p57) and Atrogin1 and Murf1 mRNAs in differentiated C2C12 myotubes after PAI-1 and Dex treatment (n = 6–8 per group). (F) Representative western blot images (left panel) and corresponding quantification (right panels) of FoxO3 and FoxO1 proteins in the nucleus of differentiated C2C12 myotubes (n = 3 per group). Scale bar in (c) and (d), 100µm). All data are presented as means±S.E. Statistical significance was determined by Student’s t-test. *, p<0.05; **, p<0.01; †, p<0.001.