Figure 3

ROS and its effects on the viability of NB4 and THP-1 under hypoxia. NB4 and THP-1 were cultured in the same condition as cell proliferation assay for 48 hours with or without NAC 0.5 mM. ROS levels were measured by using CellROX Deep Red Reagent. The viable cell numbers of NB4 and THP-1 with or without NAC 0.5 mM were examined by annexin V / PI method in triplicate. ROS level of NB4 (A) was much higher under 48 hours hypoxia (red line) than normoxia (black line). Incubation with NAC made ROS level decreased in NB4 under hypoxia (blue line). NAC treatment increased viable cells cultured under hypoxia (p = 0.0002) (B right), although the effect of NAC was not so obvious under normoxia (p = 0.0285) (B left). On the other hand, THP-1 did not show ROS increase under hypoxia and addition of NAC did not work as same as NB4 (C, D). black line: ROS level under normoxia as control, red line: under hypoxia, blue line: under hypoxia with NAC. H: under hypoxia, N: under normoxia. *** p < 0.001, * p < 0.05, ns p > 0.05 (unpaired, two-tailed t-test).