Utility of frozen cell lines in medium throughput electrophysiology screening of hERG and NaV1.5 blockade |
| |
Authors: | Donovan Brian T Bakshi Tania Galbraith Sarah E Nixon Christopher J Payne Lisa A Martens Stan F |
| |
Affiliation: | aScreening and Compound Profiling, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, PA 19426, USA;bInfectious Diseases CEDD, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, PA 19426, USA;cBiological Reagents and Assay Design, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, PA 19426, USA |
| |
Abstract: | IntroductionThe development of drug candidates must take into account that many compounds have off-target activity against voltage-gated ion channels (VGIC) which may prevent their progression to market. Of particular concern are hERG and hNaV1.5. Screening against these ion channels is necessary but expensive, partially due to maintenance of constantly cultured cell lines. Here, we show that frozen HEK-293 cells can be maintained indefinitely, reducing variability in cell performance, time and expense of cell culture.MethodsCells, constantly cultured or frozen, were assayed on the PatchXpress 7000A using tool compounds.ResultsAmitriptyline, quinidine, compound A, fluoxetine and imipramine inhibited hERG with IC50s (paired values denote constantly cultured and frozen, respectively) of 4.8 ± 0.4 and 5.1 ± 0.4, 1.4 ± 0.1 and 1.1 ± 0.1, 24.4 ± 2.4 and 21.9 ± 1.8, 2.1 ± 0.4 and 2.1 ± 0.1, 5.2 ± 0.4 and 4.0 ± 0.2 μM. Quinidine, flecainide, mexiletine and amitriptyline inhibited hNaV1.5 with IC50s of 46.6 ± 4.3 and 28.0 ± 2.3, 7.6 ± 0.7 and 6.2 ± 0.5, 153.5 ± 13.0 and 106.0 ± 4.7, 5.5 ± 0.5 and 4.8 ± 0.2 μM. Voltage dependences of activation (V1/2) for hERG were statistically identical, 0.4 ± 0.8 mV and 2.5 ± 0.5 mV. In hNaV1.5, the V1/2 of inactivation and activation were statistically identical, −82.7 ± 0.1 mV versus − 84.9 ± 0.3 mV, −47.5 ± 0.3 mV versus − 45.0 ± 0.6 mV. Current density in both conditions in hERG experiments was similar, 47.0 ± 4.1 pA versus 42.3 ± 6.0 pA/pF.DiscussionhERG and hNaV1.5 screens run using frozen cells have statistically identical IC50s, voltage dependence of activation, IV relationships and current density to screens using continuously cultured cells. Frozen cells have more constant performance and allow rapid switching between experiments on several cell lines without sacrificing data quality. |
| |
Keywords: | Abbreviations: ANOVA, analysis of variance test CHO, Chinese hamster ovary Cm, membrane capacitance DMSO, dimethyl sulfoxide EDTA, Ethylenediaminetetraacetic acid FBS, fetal bovine serum FTE, full time employee FTIH, first time in humans HBSS, Hank's buffered salt solution HEK (or HEK-293), human embryonic kidney hERG, human ether-a-go-go related gene IC50, 50% inhibitory concentration IKr, rapidly activating delayed rectifier potassium current IV, current&ndash voltage relationship LQTS, long QT syndrome ms, milliseconds mV, millivolts NaV1.5, cardiac voltage-gated sodium channel type 1.5 NMDG, N-methyl font-variant: small-caps" >d-gluconate PBS, phosphate-buffered saline pIC50, 50% inhibitory concentration in log [M] Ra, access resistance Re, electrode resistance Rm, membrane resistance V1/2, voltage for half-maximal activation of the current or voltage for half-maximal inactivation |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|