16HBE14o- Human Bronchial Epithelial Cell Layers Express P-Glycoprotein, Lung Resistance-Related Protein, and Caveolin-1

C Ehrhardt, C Kneuer, M Laue, UF Schaefer… - Pharmaceutical …, 2003 - Springer
C Ehrhardt, C Kneuer, M Laue, UF Schaefer, KJ Kim, CM Lehr
Pharmaceutical research, 2003Springer
Purpose. To study the expression of P-glycoprotein (P-gp), lung resistance-related protein
(LRP), and caveolin-1 (cav-1) in the human bronchial epithelial cell line 16HBE14o-.
Methods. The presence of P-gp, LRP, and cav-1 in 16HBE14o-cell layers was evaluated
using immunocytochemical staining and visuali-zation with confocal laser scanning
microscopy (CLSM). Functionality of P-gp was determined by bidirectional transport of
rhodamine-123 with and without a P-gp inhibitor, verapamil. Caveolae were visualized …
Abstract
Purpose. To study the expression of P-glycoprotein (P-gp), lung resistance-related protein (LRP), and caveolin-1 (cav-1) in the human bronchial epithelial cell line 16HBE14o-.
Methods. The presence of P-gp, LRP, and cav-1 in 16HBE14o- cell layers was evaluated using immunocytochemical staining and visuali- zation with confocal laser scanning microscopy (CLSM). Functionality of P-gp was determined by bidirectional transport of rhodamine-123 with and without a P-gp inhibitor, verapamil. Caveolae were visualized using transmission electron microscopy (TEM). Flux of fluorescein-Na was also studied as a paracellular transport marker.
Results. Immunocytochemical staining showed expression of P-gp localized at the apical membrane of 16HBE14o- cell layers. The flux of rhodamine 123 across cell layers exhibited a greater P app value for the secretory (i.e., basolateral-to-apical) direction. This asymmetry disappeared in the presence of verapamil. CLSM provided evidence for the expression of LRP and cav-1. TEM further showed typically shaped caveolae at the apical and basolateral membranes.
Conclusion. Cell layers of 16HBE14o- express drug transport systems that are also present in the human bronchus in vivo, indicating that the 16HBE14o- cell line may be a suitable candidate for an in vitro model for mechanistic studies of drug transport processes involved in the smaller airways.
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