Fig. 7

Rapamycin attenuated cellular senescence induced by catalase-deficient cell. A MEFs at P2 and P5 were treated with 1 μM rapamycin (rapa) overnight and senescence-associated β-galactosidase staining was analyzed. The intensities of senescent cells was analyzed in WT and KO MEFs treated with rapa. Positive intensities of β-galactosidase staining were measured using the ImageJ software. Bar graph represents mean ± SD (n = 3). Scale bar represents 200 μm. B Protein was extracted from MEFs as in A. Immunoblot analysis was performed using whole-cell lysates for senescence related antibodies. C, D Quantified protein level of P21and P16 normalized with actin. E Immunoblot analysis was performed using whole-cell lysates for autophagy and mTORC1-related antibodies. F Lysates of MEFs treated as in a were fractioned as explained in the Materials and Methods section. Equivalent volumes of each fraction were subjected to immunoblotting using cath D antibodies. G Quantified protein level of cathD on pellet and supernatant fractionations, normalized with ponceus S. H Relative cath D levels were measured from MEF lysates, treated as in a. Bar graph represents mean ± SD (n = 3 experiments). *P < 0.05, WT P5 versus KO P5. I Representative fluorescence image of MEFs treated as in a, immunostained with Lysotracker (red) and DAPI (blue). Scale bar represents 20 μm. Bar graph represents mean ± SD (n = 3 experiments). *P < 0.05; **P < 0.0001