Permeability glycoprotein (P-gp) is an active efflux membrane transporter that has been researched extensively due to its ability to confer multidrug resistance in a wide range of cancers. P-gp has an impressively broad substrate specificity and is known to interact with hundreds of compounds, including drugs and toxins. This substrate promiscuity is the key to its physiological role, and P-gp is thought to be responsible for extruding xenobiotics and cellular metabolites, as well as maintaining tissue barriers at the blood-brain interface and gastrointestinal epithelium. In addition, P-gp is thought to be involved in regulating immune responses and is able to influence the secretion of cytokines and chemokines. This role as an immunomodulator links P-gp activity in the sinonasal epithelium with chronic rhinosinusitis (CRS), and a series of studies have provided evidence suggesting that P-gp may be a potential therapeutic target for treating CRS. Here, we highlight key knowledge about this intriguing protein, which may offer an important advancement in our understanding of CRS pathogenesis.
© 2016 S. Karger AG, Basel.