Figure 4
Cigarette smoke extract (CSE) effects on hypoxia-inducible factor 1α (HIF-1α) protein stability and synthesis.
(a) A549 cells were exposed to the indicated conditions for 4 h prior to analysis of HIF-1α mRNA using real-time reverse transcriptase polymerase chain reaction (RT-PCR). Fold expression was calculated relative to untreated cells. Data are presented as the mean ± SD; *p < 0.05, as compared with the control (no treatment); #p < 0.05 for the indicated comparisons. (b,c) A549 cells were exposed to the indicated conditions for 4 h and then cycloheximide (CHX; 100 μM). The cells were incubated for the indicated times prior to whole cell lysate immunoblotting using anti-HIF-1α and anti-β-actin antibodies (b). Mean expression ratios, relative to control cells, were calculated from densitometry of two independent immunoblots and shown in (c). (d) A549 cells were treated as indicated under 20% O2 prior to immunoblotting (IB) for the indicated proteins.
