Figure 2.

F-actin (filamentous actin) dynamics in human airway smooth muscle (HASM) are consistent with a TAS2R14-mediated relaxation effect. (A and B) F-actin colocalizes with cofilin in HASM exposed to the TAS2R14 agonists DPD and AA. Cells were treated with the procontractile agents ET-1 or histamine alone or with a procontractile agent and either AA or DPD. In the representative merged confocal image, the colors of the indicated proteins or DAPI staining are indicated, with yellow representing colocalization of F-actin and cofilin. The bar graph shows results from four experiments (multiple images/experiment). Because DPD is a pharmacologic antagonist at the histamine H₁-receptor, the histamine + DPD combination was not tested. (C and D) The F-actin to G-actin ratio is altered by DPD. Representative western blot and graph of five experiments are shown. *P < 0.01 compared with vehicle; white scale bar, 20 μm; magnification, 40×.