Fig. 5

Expression of PAR2 in HFL-1 cells. RTqPCR was used to confirm the expression of the serine protease receptor PAR2 on HFL-1. The relative gene expression was related to the housekeeping gene 18 s (n = 2, 1 experiment). Human lung fibroblasts, HFL-1, showed a high gene expression for PAR2, while LAD2 cells did not show any PAR2 gene expression (a). Expression of PAR2 examined in monolayer cultures of HFL-1, LAD2, and in co-culture of HFL-1 and LAD2. Representative images are shown with PAR2 staining in yellow, mast cell specific tryptase-staining in red and nuclei stained with DAPI in blue (b-m). LAD2 cells stained by PAR2 antibodies showed no positive receptor staining (d), while HFL-1 fibroblasts showed a positive expression (h). HFL-1 showed no positive staining for tryptase (g), while mast cells were immunopositive (c). Representative scale bars are shown at the beginning of each figure (b, f, j) and indicated as 20 μm