2007 Automated Electrophysiology Users Meeting
Thanks to everyone who attended our 2007 Automated Electrophysiology User Meeting, and a special thanks to our distinguished speakers, including our keynote speaker, Dr. Alfred L. George, Professor of Pharmacology and Director, Division of Genetic Medicine, Vanderbilt University.
If you missed this event, you will find several of the presentations available below for downloading. If a presentation is not available here, please contact the author directly.
Keynote Presentation
- Sodium Channel Dysfunction in Epilepsy and Migraine
Alfred L. George, Jr., M.D., Professor of Medicine and Pharmacology, Vanderbilt University, Nashville, TN
Mutations in genes encoding neuronal voltage-gated sodium channels are associated with various inherited epilepsy syndromes. Most (>150) mutations occur in SCN1A (encoding NaV1.1) and have been associated with a spectrum of epilepsy disorders ranging from a mild syndrome called generalized epilepsy with febrile seizures plus (GEFS+), to the more devastating disorder, severe myoclonic epilepsy of infancy (SMEI). We have ascertained the biophysical properties of several mutants using heterologous expression of recombinant human NaV1.1. Among the functional alleles, many exhibit increased persistent current and other forms of impaired fast or slow inactivation. Mutations associated with SMEI frequently, but not always, cause non-functional channels. Recently, a novel SCN1A mutation (Q1489K) was identified in the syndrome of familial hemiplegic migraine. The functional behavior of Q1489K channels has interesting differences when compared to the epilepsy-associated mutations. We have also employed computational strategies to discern the mechanistic basis for increased persistent current and for predicting response to drugs. These data provide insight into the pathogenesis of epilepsy and migraine, stimulate renewed interest in brain sodium channels as potential therapeutic targets in this common disorder, and illustrate a complexity of genotype-phenotype relationships among the brain sodium channelopathies.
- Using the IonWorks Quattro to Measure Non-Voltage-Gated channels
Dr. M. Gosling, Novartis
- Utilization of the PatchXpress 7000A to Investigate Calcium Activated K+ Channels
Dr. H. Draheim, Boehringer Ingelheim
- The Sweet Smell of Xpress
Dr. C. Luetje, University of Miami - Use of Automated Electrophysiology for Ion Channel Target Validation
Dr. J. Herrington, Merck & Co
- Dynamic Test Procedures Improve the Relevance of Electrophysiological Measurements
Dr. T. Guia, Aviva Biosciences
- Validation of a Comprehensive Ion Channel Library Using Automated Patch Clamping
Dr. B. Wible, ChanTest - Cell Line Optimization for PatchXpress
Dr. R. Petroski, Neurocrine Biosciences
- Assay Development and Primary Screening of Non-Voltage-Gated Ion Channels Using IonWorks Quattro
A. Wittel, Amgen - Pharmacology and Assay Optimization of KCNQ Compounds Using IonWorks HT
Dr. M. Bowlby, Wyeth Research
Posters:
- Validation of a Comprehensive Ion Channel Library Using Automated Patch Clamping
Yuri A. Kuryshev, Yuan Chen, Joerg Oestreich, Heather Eng, Lisa Dewey, Zhiqi Liu, Glenn Kirsch, Arthur M. Brown, and Barbara A. Wible, ChanTest, Inc.
ChanTest, Inc. is developing an Ion Channel PanelTM for use in drug safety, selectivity, and discovery platforms. The catalog will consist of more than 70 cell lines overexpressing a collection of the most relevant ion channels in drug discovery, safety pharmacology and toxicology, and human disease. Construction of this panel involves cloning human cDNAs encoding the ion channel genes, stable transfection into heterologous mammalian cell lines, and electrophysiological characterization and validation of each cell line for functional analysis of drug effects. The cell lines are optimized for use on ChanTest’s automated electrophysiology systems, PatchXpress® 7000A (MDC) and IonWorks® QuattroTM (MDC), to achieve the lower cost and higher throughput that the industry demands. IonWorks® QuattroTM is used for clonal selection of both HEK and CHO cell lines overexpressing voltage-gated ion channels and CHO cell lines are validated for screening in Population Patch ClampTM (PPC) mode. PatchXpress® 7000A is used for validation of both HEK and CHO cell lines expressing voltage-gated, non-voltage-gated, and ligand-gated ion channels. Several examples of validated cell lines are presented.
- Automation of online decision making and offline analysis in the PatchXpress 7000A electrophysiology system
Naibo Yang, Jim Costantin, Richard Kondo, Jan Dolzer, Molecular Devices Corporation
Introduced within the past several years. While automated parallel patch clamp increases throughput, new challenges are created, such as how to make decisions in real-time during an experiment as well as management and analysis of all the data generated. The PatchXpress 7000A system comes with a sophisticated combination of system control software (PatchXpress Commander) and data management, analysis software (DataXpress). PatchXpress Commander provides complete control of the PatchXpress 7000A system, and includes a collection of ready-touse script functions that cover common scenarios for online decision-making based on ion channel expression level, current stability, drug effect or washing effect, etc. Scripts can also be used to change control parameters such as the holding potential, while the experiment is running. DataXpress 2 provides data management as well as macro-driven, automated data analysis functionality. While the data management functionality allows users to easily sort, access and protect collected data, the new macro capability provides users with the ability to quickly generate processes for automated data analysis, such as time course IC50/EC50 plots, I-V analysis, time constant analysis and many more scenarios.
- A fluorescence-based FLIPR® assay for Potassium Channels using a Thallium sensitive probe and MDC’s proprietary masking dye technology.
Jeff Quast, Rheka Thomas, Sukanta Bhattacharyya, Annegret Boge and Rich Sportsman
Molecular Devices Corporation
Potassium channels are important targets for a large number of therapeutic indications as well as for safety profiling of new drugs. Most commonly, K+ channels are assayed with patch clamp techniques that have medium to low throughput, or else with fluorescent membrane potential dyes. The latter allows for high-throughput but often is somewhat lacking in specificity. The ability to use a high-throughput functional assay for the detection and characterization of small-molecule modulators of potassium channels is therefore very desirable. Weaver et al (1) described a specific Potassium channel assay based on a Thallium sensitive probe and its use for High Throughput Screening at BMS. This poster presents data for further development of this technology in combination with MDC’s proprietary masking dye technology. The resulting assay can be used for detection of modulators for ligand- and voltage-gated Potassium channels expressed in mammalian cells in an automation friendly, homogenous assay format for example on FLIPR or Tetra . This poster presents first data generated with research materials.
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