title: Targeting kidney CLC-K channels: pharmacological profile in a human cell line versus Xenopus oocytes.
abstract: CLC-K chloride channels play a crucial role in kidney physiology and genetic mutations, affecting their function are responsible for severe renal salt loss in humans. Thus, compounds that selectively bind to CLC-Ka and/or CLC-Kb channels and modulate their activity may have a significant therapeutic potential. Here, we compare the biophysical and pharmacological behaviors of human CLC-K channels expressed either in HEK293 cells or in Xenopus oocytes and we show that CLC-K channel properties are greatly influenced by the biochemical environment surrounding the channels. Indeed, in HEK293 cells the potentiating effect of niflumic acid (NFA) on CLC-Ka/barttin and CLC-Kb/barttin channels seems to be absent while the blocking efficacy of niflumic acid and benzofuran derivatives observed in oocytes is preserved. The NFA block does not seem to involve the accessory subunit barttin on CLC-K1 channels. In addition, the sensitivity of CLC-Ks to external Ca(2+) is reduced in HEK293 cells. Based on our findings, we propose that mammalian cell lines are a suitable expression system for the pharmacological profiling of CLC-Ks.
authors.affiliation: Dipartimento di Farmacia - Scienze del Farmaco, Università degli Studi di Bari, Via Orabona 4, 70125 Bari, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Imbrici
authors.affiliation: Dipartimento di Farmacia - Scienze del Farmaco, Università degli Studi di Bari, Via Orabona 4, 70125 Bari, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Liantonio
authors.affiliation: Istituto di Biofisica, CNR, Via De Marini 6, 16149 Genova, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Gradogna
authors.affiliation: Istituto di Biofisica, CNR, Via De Marini 6, 16149 Genova, Italy.
authors.forename: Michael
authors.initials: M
authors.lastname: Pusch
authors.affiliation: Dipartimento di Farmacia - Scienze del Farmaco, Università degli Studi di Bari, Via Orabona 4, 70125 Bari, Italy. Electronic address: diana.conte@uniba.it.
authors.forename: Diana Conte
authors.initials: DC
authors.lastname: Camerino
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000493:pharmacokinetics / Q000494:pharmacology; D001572:Benzofurans / Q000493:pharmacokinetics / Q000494:pharmacology; D018118:Chloride Channels / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D016503:Drug Delivery Systems; D057809:HEK293 Cells; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D009544:Niflumic Acid / Q000493:pharmacokinetics / Q000494:pharmacology; D009865:Oocytes / Q000166:cytology / Q000378:metabolism*; D013045:Species Specificity; D014982:Xenopus laevis
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D001572:Benzofurans; C489932:CLCNKA protein, human; C412733:CLCNKB protein, human; D018118:Chloride Channels; D009544:Niflumic Acid; C105430:benzofuran
keywords: Bartter syndrome; CLC-K chloride channel; HEK293 cell; Hypertension; Kidney; Pharmacology