Nedocromil activates PKC_α/β and promotes Anx-A1 phosphorylation.

<p>Panel A. Aliquots of 2×10⁵ CDMC cells were cultured as described and incubated for 5 min with vehicle alone or escalating concentrations of nedocromil (Ned; 2-20 nM). The cell medium was then harvested and the cells lysed. Western blotting was used to assess the intracellular concentration of phospho-PKC and Ser²⁷-phopsho-Anx-A1. A maximum effect was seen at 5 nM nedocromil at this time point. A representative blot from duplicate experiments. Panel B. Using a similar methodology, the time course of activation of PKC was assessed using nedocromil (Ned; 10 nM). A maximum effect was seen at 5 min treatment with the drug at this concentration. A representative blot from duplicate experiments. Panel C. Using samples of lysate prepared from CDMC cells treated with nedocromil (Ned; 5 nM) for 5 min, the relative abundance of three activated isoforms of PKC was assessed using specific antisera. Only PKC α/β was increased by nedocromil treatment. Activated PKC δ oρ θ isoforms were not detected in resting or stimulated cells under these experimental conditions.