title: SKCa Channels Blockage Increases the Expression of Adenosine A2A Receptor in Jurkat Human T Cells.
abstract: Adenosine is a nucleoside displaying various biological effects via stimulation of four G-protein-coupled receptors, A1, A2A, A2B, and A3. Adenosine also modulates voltage-gated (Kv) and small conductance calcium-activated (SKCa) potassium channels. The effect of these potassium channels on the expression of adenosine receptors is poorly understood. We evaluated the action of BgK (a natural Kv channel blocker) and Lei-Dab7 (a synthetic SKCa channel blocker) on the expression of adenosine A2A receptors (A2AR) in Jurkat human T cells. We found that Lei-Dab7, but not BgK, increased the maximal binding value of the tritiated ligand ZM241385 to A2AR in a dose-dependent manner (+45% at 5 nM; +70% at 50 nM as compared to control). These results were further confirmed by Western blotting using a specific monoclonal antibody to human A2AR. The ligand affinity-related dissociation constant and A2AR mRNA amount were not significantly modified by either drug. We suggest that modulation of SKCa channels can influence membrane expression of A2AR and thus has a therapeutic potential.
authors.affiliation: Unit of Functional Proteomics and Organic Food Preservation, Higher Institute of Applied Biological Sciences of Tunis, University of Tunis El Manar , Tunis, Tunisia . ; Higher Institute of Environmental Sciences and Technologies, University of Carthage , Carthage, Tunisia .
authors.forename: Imed
authors.initials: I
authors.lastname: Regaya
authors.forename: Sabrine
authors.initials: S
authors.lastname: Aidi-Knani
authors.forename: Youlet
authors.initials: Y
authors.lastname: By
authors.forename: Jocelyne
authors.initials: J
authors.lastname: Condo
authors.forename: Victoria
authors.initials: V
authors.lastname: Gerolami
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Berge-Lefranc
authors.forename: Jeannette
authors.initials: J
authors.lastname: Ben Hamida
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Sabatier
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Fenouillet
authors.forename: Régis
authors.initials: R
authors.lastname: Guieu
authors.forename: Jean
authors.initials: J
authors.lastname: Ruf
keywords: cardiology; cellular biology; immunology; neurobiology