Fig. 2.
Response of ihNSC to IR-induced DNA damage. (A) At the indicated days of differentiation (D) cells were irradiated and analyzed 1 h later by western blot for the autophosphorylation of ATM-S1981 and phosphorylation of the ATM targets Smc1-S966, Chk2-T68 and p53-S15. Protein loading per lane was verified with anti-β-Actin antibodies (B) The formation and loss of damage-induced γ-H2AX nuclear foci was assessed on cells at D0 or D17 (cultured and differentiated in 5% or 1% O2, as indicated) which were treated with 1 Gy or 0.88 nM NCS respectively, collected at the indicated time points and IF-labeled for γ-H2AX. For each treatment, the number of foci was scored from over 100 cell nuclei per duplicate preparations and from three independent experiments (mean ± S.D.). For each time point, the difference between shCon and shATM was statistically significant (**P < 0.01) except for those indicated with n.s.