FIGURE 3.

HIF-1α alone is incapable of inducing its target genes without accompanying exposure to hypoxia. 3T3-L1 preadipocytes were differentiated until day 8, and then cells were exposed to 20% or 1% O₂ for 18 h. Some cells were also exposed to 200 μm YC-1 under hypoxia for 18 h or to 200 μm CoCl₂ under normoxia for 6 h. The cells were immediately harvested for protein isolation and Western blot analysis (A) or for RNA isolation and quantitative real-time PCR analysis (B). Results are means ± S.E. (n = 3).