Studying mechanosensitive ion channels with an automated patch clamp

2014 ◽  
Vol 43 (2-3) ◽  
pp. 97-104 ◽  
Author(s):  
Maria Barthmes ◽  
Mac Donald F. Jose ◽  
Jan Peter Birkner ◽  
Andrea Brüggemann ◽  
Christian Wahl-Schott ◽  
...  
Keyword(s):  
Ion Channels ◽  
Patch Clamp ◽  
Mechanosensitive Ion Channels ◽  
Automated Patch Clamp

scholarly journals Characterizing Human Ion Channels in Induced Pluripotent Stem Cell–Derived Neurons

2012 ◽  
Vol 17 (9) ◽  
pp. 1264-1272 ◽  
Author(s):  
Alison Haythornthwaite ◽  
Sonja Stoelzle ◽  
Alexander Hasler ◽  
Andrea Kiss ◽  
Johannes Mosbacher ◽  
...  
Keyword(s):  
Stem Cell ◽  
Ion Channels ◽  
Patch Clamp ◽  
Pluripotent Stem Cell ◽  
Induced Pluripotent Stem Cell ◽  
Excitable Cells ◽  
Automated Patch Clamp ◽  
Induced Pluripotent ◽  
Two Populations ◽  
A Current

Neurons derived from human-induced pluripotent stem cells were characterized using manual and automated patch-clamp recordings. These cells expressed voltage-gated Na+ (Nav), Ca2+ (Cav), and K+ (Kv) channels as expected from excitable cells. The Nav current was TTX sensitive, IC50 = 12 ± 6 nM ( n = 5). About 50% of the Cav current was blocked by 10 µM of the L-type channel blocker nifedipine. Two populations of the Kv channel were present in different proportions: an inactivating (A-type) and a noninactivating type. The A-type current was sensitive to 4-AP and TEA (IC50 = 163 ± 93 µM; n = 3). Application of γ-aminobutyric acid (GABA) activated a current sensitive to the GABAA receptor antagonist bicuculline, IC50 = 632 ± 149 nM ( n = 5). In both devices, comparable action potentials were generated in the current clamp. With unbiased, automated patch clamp, about 40% of the cells expressed Nav currents, whereas visual guidance in manual patch clamp provided almost a 100% success rate of patching “excitable cells.” These results show high potential for pluripotent stem cell–derived neurons as a useful model for drug discovery, in combination with automated patch-clamp recordings for high-throughput and high-quality drug assessments at human neuronal ion channels in their correct cellular background.

scholarly journals Automated Patch Clamp on mESC-Derived Cardiomyocytes for Cardiotoxicity Prediction

2011 ◽  
Vol 16 (8) ◽  
pp. 910-916 ◽  
Author(s):  
Sonja Stoelzle ◽  
Alison Haythornthwaite ◽  
Ralf Kettenhofen ◽  
Eugen Kolossov ◽  
Heribert Bohlen ◽  
...  
Keyword(s):  
Stem Cell ◽  
Ion Channels ◽  
Patch Clamp ◽  
Cell Model ◽  
Single Type ◽  
Ion Currents ◽  
Drug Induced ◽  
Cardiovascular Side Effects ◽  
Automated Patch Clamp

Cardiovascular side effects are critical in drug development and have frequently led to late-stage project terminations or even drug withdrawal from the market. Physiologically relevant and predictive assays for cardiotoxicity are hence strongly demanded by the pharmaceutical industry. To identify a potential impact of test compounds on ventricular repolarization, typically a variety of ion channels in diverse heterologously expressing cells have to be investigated. Similar to primary cells, in vitro–generated stem cell–derived cardiomyocytes simultaneously express cardiac ion channels. Thus, they more accurately represent the native situation compared with cell lines overexpressing only a single type of ion channel. The aim of this study was to determine if stem cell–derived cardiomyocytes are suited for use in an automated patch clamp system. The authors show recordings of cardiac ion currents as well as action potential recordings in readily available stem cell–derived cardiomyocytes. Besides monitoring inhibitory effects of reference compounds on typical cardiac ion currents, the authors revealed for the first time drug-induced modulation of cardiac action potentials in an automated patch clamp system. The combination of an in vitro cardiac cell model with higher throughput patch clamp screening technology allows for a cost-effective cardiotoxicity prediction in a physiologically relevant cell system.

Identification of Mechanosensitive Ion Channels in the Cytoplasmic Membrane of Corynebacterium glutamicum

1999 ◽  
Vol 181 (5) ◽  
pp. 1673-1676 ◽  
Author(s):  
Susanne Ruffert ◽  
Catherine Berrier ◽  
Reinhard Krämer ◽  
Alexandre Ghazi
Keyword(s):  
Ion Channels ◽  
Patch Clamp ◽  
Corynebacterium Glutamicum ◽  
Cytoplasmic Membrane ◽  
Voltage Dependence ◽  
Ion Selectivity ◽  
Mechanosensitive Ion Channels

ABSTRACT Patch-clamp experiments performed on membrane fragments ofCorynebacterium glutamicum fused into giant liposomes revealed the presence of two different stretch-activated conductances, 600 to 700 pS and 1,200 to 1,400 pS in 0.1 M KCl, that exhibited the same characteristics in terms of kinetics, ion selectivity, and voltage dependence.

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