Multi-parametric assessment of cardiomyocyte excitation-contraction coupling using impedance and field potential recording: A tool for cardiac safety assessment.
BACKGROUND
The ICH S7B guidelines recommend that all new chemical entities should be subjected to hERG repolarization screening due to its association with life-threatening "Torsades de Pointes" (TdP) arrhythmia. However, it has become evident that not all hERG channel inhibitors result in TdP and not all compounds that induce QT prolongation and TdP necessarily inhibit hERG. In order to address the limitations of the S7B/E14 guidelines, the FDA through a public/private partnership initiated the Comprehensive in vitro Proarrhythmia Assay (CiPA) initiative to examine the possible modification and refinement of the ICH E14/S7B guidelines. One of the main components of the CiPA initiative is to utilize a predictive assay system together with human cardiomyocytes for risk assessment of arrhythmia.


METHODS
In this manuscript we utilize the xCELLigence® CardioECR system which simultaneously measures excitation-contraction coupling together with human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) to assess the effect of 8 reference compounds across 3 different independent sites. These 8 compounds were part of Phase I CiPA validation study.


RESULTS
Our data demonstrate that hERG channel blockers, such as E4031 and moxifloxacin, prolonged field potential duration (FPD) at low concentration and induced arrhythmic beating activity as measured by field potential (FP) recording and impedance (IMP) recordings at higher concentrations. On the contrary, nifedipine, an inhibitor of calcium channel, didn't disrupt the periodicity of cell beating and weakened cell contractile activity and shortened FPD. Multichannel inhibitors, such as flecainide, quinidine and mexiletine, not only increased FPD and induced arrhythmia but also significantly reduced the amplitude of FP spike. JNJ303, an IKs inhibitor, only affected FPD. Comparison of the compound effect on FPD across the 3 different sites is consistent in terms of trend of the effect with observed 3-10 fold differences in minimal effective concentration at which a minimum of 10% response is detected. In addition, pentamidine, a hERG trafficking inhibitor which induced irregular beating activity over a more prolonged duration of time was readily flagged in this assay system. Taken together, this multi-parameter assay using hiPSC-CMs in conjunction with simultaneous measurement of ion channel activity and contractility can be a reliable approach for risk assessment of proarrhythmic compounds.
ACEA Biosciences, Inc., San Diego, CA 92121, USA.
Xiaoyu
X
Zhang
Laboratory of Investigative Toxicology, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.
Liang
L
Guo
SALAR, Safety & Exploratory Pharmacology Department, Merck Research Laboratories, West Point, PA 19486, USA.
Haoyu
H
Zeng
Drug Synthesis & Chemistry Branch, Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Stephen L
SL
White
Laboratory of Investigative Toxicology, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.
Michael
M
Furniss
SALAR, Safety & Exploratory Pharmacology Department, Merck Research Laboratories, West Point, PA 19486, USA.
Bharathi
B
Balasubramanian
SALAR, Safety & Exploratory Pharmacology Department, Merck Research Laboratories, West Point, PA 19486, USA.
Edward
E
Lis
SALAR, Safety & Exploratory Pharmacology Department, Merck Research Laboratories, West Point, PA 19486, USA.
Armando
A
Lagrutta
SALAR, Safety & Exploratory Pharmacology Department, Merck Research Laboratories, West Point, PA 19486, USA.
Frederick
F
Sannajust
ACEA Biosciences, Inc., San Diego, CA 92121, USA.
Li Leyna
LL
Zhao
ACEA Biosciences, Inc., San Diego, CA 92121, USA.
Biao
B
Xi
ACEA Biosciences, Inc., San Diego, CA 92121, USA.
Xiaobo
X
Wang
Toxicology and Pharmacology Branch, Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Myrtle
M
Davis
ACEA Biosciences, Inc., San Diego, CA 92121, USA. Electronic address: yabassi@aceabio.com.
Yama A
YA
Abassi
D000200:Action Potentials / Q000187:drug effects*; D001145:Arrhythmias, Cardiac / Q000139:chemically induced* / Q000503:physiopathology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004353:Drug Evaluation, Preclinical / Q000379:methods; D017408:Guidelines as Topic; D006801:Humans; D057026:Induced Pluripotent Stem Cells; D009200:Myocardial Contraction / Q000187:drug effects*; D032383:Myocytes, Cardiac / Q000187:drug effects*; D026902:Potassium Channel Blockers / Q000494:pharmacology; D012449:Safety; D016171:Torsades de Pointes / Q000139:chemically induced
D026902:Potassium Channel Blockers
Arrhythmia; CardioECR; Cardiomyocytes; Contractility; iPSC