Fig. 1.

Increase in glycogen synthase kinase 3 (GSK3) phosphorylation and mature sterol regulatory element binding protein 1 (SREBP1) in stress-induced senescence. Chang cells were treated with 200 µM deferoxamine (DFO) or H₂O₂ for the indicated periods. Dimethyl sulfoxide (DMSO) was used as vehicle control (V). (A) Flow cytometric analysis of the cell distribution after treatment of the stressors (200 µM DFO or H₂O₂) for 3 days. Cell size and cell granularity were analyzed by comparing forward scatter (FSC; R2+R4) and side scatter (SSC; R1+R2). Representative profiles (left) and their analyses for cell granularity (SCC analysis, right upper) and cell size (FSC analysis, right lower) are shown. (B) Representative images of senescence-associated β-galactosidase-positive cell populations are shown. (C) Western blot analysis. Quantitative analyses of the expression levels of SREBP1 mature form are shown in the lower panels. mSREBP1, mature-form SREBP1; pGSK, phosphor-GSK. ^aP<0.01 vs. V (DMSO control).