Figure 4.
CRH increased stem cell factor (SCF) expression in the mucosal epithelium in NPs. (a) SCF immunofluorescence of organ-cultured human NPs treated with vehicle or CRH (10−7 M). CRH significantly increased SCF expression within the epithelium of 1 day organ-cultured human NPs. The arrow denotes SCF-positive immunoreactivity within the epithelium. n = 6; scale bar = 50 µm. (b) Double immunofluorescence for AE1/3/SCF and (c) tryptase/SCF of CRH-treated NPs. Most of the SCF+ cells were epithelial cells. Some tryptase+ hM-MCs within the epithelium expressed SCF. The arrow denotes SCF+ hM-MCs; n = 4 in (b) and 6 in (c). Scale bar = 10 µm in (b), 20 µm in (c). (d) SCF immunoreactivity in NP epithelium with CRH-R1 siRNA-treated human NPs. The arrow denotes SCF-positive immunoreactivity within the epithelium. n = 4; scale bar = 20 µm. Error bars indicate SEM. *p < 0.05, ** p < 0.01. MC, mast cell; SCF, stem cell factor; hM-MCs, human nasal mucosa MCs; NPs, nasal polyps; CRH, corticotropin-releasing hormone; CRH-R1, CRH receptor type 1; CRH-R1 siRNA, CRH-R1 siRNA-treated NPs; SCR, scrambled siRNA-treated NPs; DAPI, diamidino-2-phenylindole.