Research Paper Volume 10, Issue 11 pp 3574—3589

Suppression of mTORC1 activity in senescent Ras-transformed cells neither restores autophagy nor abrogates apoptotic death caused by inhibition of MEK/ERK kinases

Figure 8. Senescent cells require active MEK/ERK pathway to implement degradation of the damaged mitochondria through their segregation into the LC3-negative vacuoles. (A) Cells exposed to MEK/ERK inhibitor do not segregate of lysosomes in the LC3-negative vacuoles (upper panel). IF images after staining with antibodies against LC3 and LAMP1) or mitochondria (bottom panel), IF images after staining with antibodies against TOM20 and LAMP1) of the LC3-negative vacuoles. (B) TEM of a senescent cell after MEK/ERK suppression undergoing complete destruction of the cytoplasm without segregation and elimination of the damaged mitochondria. (C) TEM image of senescent cells exposed to pp242 + PD0325901 showing destruction of the cytoplasm and dispersed damaged mitochondria. Scale bars: 1 µm.