Effect of PGE2 and dBcAMP on CCR5 mRNA expression. (A) Human monocytes were incubated for 4 hours with graded concentrations of PGE2 or dBcAMP and total RNA was extracted, separated, and analyzed by Northern blotting for CCR5 mRNA expression. (B) Kinetics of PGE2 downregulation of CCR5 gene expression. Cells were incubated in the absence or presence of PGE2 10−5 mol/L for the indicated time periods followed by Northern blot analysis of CCR5 mRNA expression. (C) Effect of PGE2 on CCR5 mRNA stability. Monocytes were incubated 1 hour with medium or PGE2 10−5mol/L before mRNA synthesis was stopped by the addition of actinomycin D (5 μg/mL). At the indicated times thereafter, total RNA was prepared and analyzed by Northern blot. The figure illustrates the autoradiogram of one representative experiment with percentages of remaining CCR5 mRNA relative to the values at time 0, corrected for corresponding GAPDH values. n = 2 to 4 independent experiments.
