Probenecid blocks human P2X7 receptor-induced dye uptake via a pannexin-1 independent mechanism

Authors

Archana Bhaskaracharya, University of Sydney
Phuong Dao-Ung, University of Sydney
Iman Jalilian, University of WollongongFollow
Mari Spildrejorde, University of WollongongFollow
Kristen K. Skarratt, University of Sydney
Stephen Fuller, University of Sydney
Ronald Sluyter, University of WollongongFollow
Leanne Stokes, University of Sydney

RIS ID

88797

Publication Details

Bhaskaracharya, A., Dao-Ung, P., Jalilian, I., Spildrejorde, M., Skarratt, K. K., Fuller, S. J., Sluyter, R. & Stokes, L. (2014). Probenecid blocks human P2X7 receptor-induced dye uptake via a pannexin-1 independent mechanism. PLoS One, 9 (3), e93058-1-e93058-8.

Abstract

P2X7 is a ligand-gated ion channel which is activated by ATP and displays secondary permeability characteristics. The mechanism of development of the secondary permeability pathway is currently unclear, although a role for the hemichannel protein pannexin-1 has been suggested. In this study we investigated the role of pannexin-1 in P2X7-induced dye uptake and ATP-induced IL-1β secretion from human monocytes. We found no pharmacological evidence for involvement of pannexin-1 in P2X7-mediated dye uptake in transfected HEK-293 cells with no inhibition seen for carbenoxolone and the pannexin-1 mimetic inhibitory peptide, 10Panx1. However, we found that probenecid inhibited P2X7-induced cationic and anionic dye uptake in stably transfected human P2X7 HEK-293 cells. An IC50 value of 203 μM was calculated for blockade of ATP-induced responses at human P2X7. Probenecid also reduced dye uptake and IL-1β secretion from human CD14+ monocytes whereas carbenoxolone and 10Panx1 showed no inhibitory effect. Patch clamp and calcium indicator experiments revealed that probenecid directly blocks the human P2X7 receptor.