LPS increases HIF-1α mRNA expression. (A) Quiescent NR8383 cells were maintained under control conditions or in the presence of LPS (1 μg/mL) for different periods of time of up to 8 hours. (B) Quiescent NR8383 cells were maintained either under control conditions, or under hypoxic conditions, or in the presence of LPS (1 μg/mL) for 6 hours. Total RNA was extracted from cells and resolved on formaldehyde/agarose gels. Northern blot was performed using a specific radiolabeled HIF-1α probe. An 18S rRNA probe was used as a control for gel loading.