Related Experiment Videos
P-glycoprotein efflux pump expression and activity in Calu-3 cells
K O Hamilton1, G Backstrom, M A Yazdanian
1Department of Pharmaceutical Chemistry, 236B Simons Laboratories, 2095 Constant Avenue, The University of Kansas, Lawrence, Kansas 66047, USA.
Journal of Pharmaceutical Sciences
|April 5, 2001
Summary
The Calu-3 lung epithelial cell model expresses an active P-glycoprotein (Pgp) efflux pump, sensitive to cyclosporin A inhibition. This finding is crucial for understanding drug transport in lung cells.
Area of Science:
- Cell Biology
- Pharmacology
- Drug Transport
Background:
- The Calu-3 cell line is a model for human sub-bronchial epithelium.
- Understanding drug efflux pumps like P-glycoprotein (Pgp) is vital for predicting drug behavior in lung tissues.
Purpose of the Study:
- To investigate the expression and functional activity of the P-glycoprotein (Pgp) efflux pump in the Calu-3 cell line.
- To characterize the role of Pgp in the transport of Pgp substrates within this lung epithelial model.
Main Methods:
- Western Blot analysis to quantify Pgp levels.
- Assays measuring the accumulation of Pgp substrates (rhodamine 123, calcein-AM) in the presence of Pgp inhibitors (cyclosporin A, vinblastine, taxol) and MRP1 inhibitors (probenecid, indomethacin).
- Directional transport studies (basolateral-to-apical) of Pgp substrates.
Main Results:
- Calu-3 cells exhibit lower Pgp expression compared to Caco-2 and A549 cells.
- Pgp activity in Calu-3 cells was confirmed by increased substrate accumulation with Pgp inhibitors.
- Efflux pathway is energy-dependent and sensitive to cyclosporin A, with basolateral-to-apical transport being predominant.
- MRP1 inhibitors did not significantly affect Pgp substrate efflux, indicating Pgp as the primary mediator.
Conclusions:
- The Calu-3 cell line possesses a functionally active, energy-dependent P-glycoprotein (Pgp) efflux pump.
- This Pgp activity in Calu-3 cells is sensitive to inhibition by cyclosporin A, supporting its utility in studying Pgp-mediated drug transport in lung epithelium.