Fig. 4.

Conditioned media from compressed asthmatic human bronchial epithelial (HBE) cells induce augmented histamine response in human airway smooth muscle (HASM) cells. A: compression with 30 cmH₂O pressure significantly increased endothelin-1 (ET-1) secretion from both nonasthmatic and asthmatic HBE cells (n = 4, *P < 0.05 vs. 0 cmH₂O). B: conditioned media from compressed asthmatic HBE cells (30 cmH₂O) significantly increased HASM cell proliferation (n = 4, *P < 0.05 vs. vehicle medium). Pretreatment with PD-145065 did not affect HASM cell proliferation. The average number of cells counted for each condition was ~3,100, and 4 donors were used. C: pretreatment of HASM cells with PD-145065 blocked the increased traction mediated by conditioned media from compressed asthmatic HBE cells (n = 4, *P < 0.05 vs. 0 cmH₂O). D: conditioned media from asthmatic HBE cells compressed at either 10 or 30 cmH₂O significantly increased the histamine response of HASM cells (n = 4, *P < 0.05 vs. 0 cmH₂O). Pretreatment of HASM cells with PD-145065 blocked the increased histamine response. E: a significant difference induced by CM between nonasthmatic and asthmatic HBE cells was the increased contraction response [Δhistamine response traction (T_His)/baseline traction (T₀)] to histamine (10 μM) in the HASM cells, after incubation of HASM cells with CM from compressed HBE cells with 10 cmH₂O pressure (n = 4, *P < 0.05 vs. nonasthmatic cells).