Figure 4.

Human ESC (hESC) apoptosis and increased expression of FGF-2 in response to cellular stress. (A): Immunoblot of PARP and lamin B cleavage (3 hours after treatment), and (B) quantitative TUNEL (12 hours after treatment) of hESCs FGF-2 prestarved (6 hours) and incubated with 10 ng/ml FGF-2 (2 hours) and irradiated (1 Gy) or exposed to H₂O₂ (50 μM, 1 hour). Control cells were irradiated or exposed to H₂O₂ in the absence of exogenous FGF-2. (C): hESCs were treated with 25 μM H₂O₂ without exogenous FGF-2 for 12 and 24 hours and immunoblotted for endogenous FGF-2. Control cells were maintained without H₂O₂. Representative results of triplicate experiments. Abbreviations: FGF-2, fibroblast growth factor-2; IR, irradiated; PARP, poly(ADP-ribose) polymerase; TUNEL, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling.