Figure 2.

PUMA is required for DNA- damage-induced and ER-stress-induced apoptosis in cortical neurons. A, B, Cortical neurons derived from Puma wild-type and knock-out littermates were treated with 1 μm thapsigargin (TG, Tg), 3 μg/ml tunicamycin (TM, Tm), 10 μm camptothecin (CPT), or 10 μm etoposide (ETP), and the fraction of apoptotic cells was determined at 24 and 48 h by assessing nuclear morphology after Hoechst staining. The fraction of apoptotic neurons was significantly decreased in Puma^+/+ versus Puma^−/− cultures (n ≥ 7; *p < 0.001). C, Puma wild-type and knock-out cortical neurons were treated with DNA-damaging agents or ER stressors as above. Cell lysates obtained 20 h after treatment were assayed for caspase-3 activity (n = 5; *p < 0.001).