Decreased proliferation in Atm-/- astrocytes is
caused by elevated ROS levels. A, Atm+/+ and
Atm-/- astrocytes were either left untreated or pretreated
with NAC (1 mm) for 2 h. Fluorescent H2DCFDA levels were
determined for these cells. The means ± S.D. of three independent
experiments are shown. *, p < 0.05 when untreated
Atm-/- culture were compared with untreated
Atm+/+ astrocytes or when NAC-treated
Atm-/- astrocytes were compared with untreated
Atm-/- astrocytes. B, growth curves of
Atm-/- astrocytes in the presence or absence of NAC (1
mm) were analyzed for 5 days and then compared with those of
Atm+/+ astrocytes. The means ± S.D. of three
independent counting are shown. *, p < 0.05 when
NAC-treated Atm-/- astrocytes were compared with untreated
Atm-/- astrocytes. C, photomicrographs of
Atm+/+ and Atm-/- astrocytes in the
presence or absence of NAC. Scale bars, 50 μm. D,
senescence of Atm+/+ and Atm-/-
astrocytes in the presence or absence of NAC was compared by SA
β-galactosidase expression 2 days after cultivation. The means ±
S.D. of three independent experiments are shown. *, p <
0.05 when untreated Atm-/- culture was compared with
untreated Atm+/+ astrocytes or when NAC-treated
Atm-/- astrocytes was compared with untreated
Atm-/- astrocytes.