FIGURE 2.

Extracellular nucleotides induce Fos expression in primary human monocytic cells. Isolated peripheral human blood monocytes were stimulated with either 2.5 mm HEPES (vehicle (V)), 1 μg/ml LPS, 1 μg/ml PMA, 250 μm BzATP (Bz), 1 mm ATP, or 250 μm ATP, ADP, UTP, or UDP for 5 min. The cells were subsequently washed with HBSS and incubated at 37 °C with fresh complete monocyte media for 2 h and immunoblotted for c-Fos (A) or FosB (B) expression. The results of at least three independent experiments were collated and represent relative c-Fos, FosB, and ΔFosB protein expression (mean ± S.E.). C, human peripheral blood monocytes were stimulated with either vehicle (V), 250 μm BzATP (B), or 1 μg/ml PMA (P) for 5 min., washed, then lysed after the indicated times and immunoblotted for FosB/ΔFosB expression. The results from four independent experiments were summarized and represent a -fold increase in FosB/ΔFosB protein expression (mean ± S.E.). *, p < 0.05.