scholarly journals R534C mutation in hERG causes a trafficking defect in iPSC-derived cardiomyocytes from patients with type 2 long QT syndrome

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Fernanda C. P. Mesquita ◽  
Paulo C. Arantes ◽  
Tais H. Kasai-Brunswick ◽  
Dayana S. Araujo ◽  
Fernanda Gubert ◽  
...  
Keyword(s):  
Long Qt Syndrome ◽  
Mononuclear Cells ◽  
Patient Specific ◽  
Control Line ◽  
Long Qt ◽  
Peripheral Blood Mononuclear ◽  
Channel Trafficking ◽  
Qt Syndrome ◽  
Induced Pluripotent

AbstractPatient-specific cardiomyocytes obtained from induced pluripotent stem cells (CM-iPSC) offer unprecedented mechanistic insights in the study of inherited cardiac diseases. The objective of this work was to study a type 2 long QT syndrome (LQTS2)-associated mutation (c.1600C > T in KCNH2, p.R534C in hERG) in CM-iPSC. Peripheral blood mononuclear cells were isolated from two patients with the R534C mutation and iPSCs were generated. In addition, the same mutation was inserted in a control iPSC line by genome editing using CRISPR/Cas9. Cells expressed pluripotency markers and showed spontaneous differentiation into the three embryonic germ layers. Electrophysiology demonstrated that action potential duration (APD) of LQTS2 CM-iPSC was significantly longer than that of the control line, as well as the triangulation of the action potentials (AP), implying a longer duration of phase 3. Treatment with the IKr inhibitor E4031 only caused APD prolongation in the control line. Patch clamp showed a reduction of IKr on LQTS2 CM-iPSC compared to control, but channel activation was not significantly affected. Immunofluorescence for hERG demonstrated perinuclear staining in LQTS2 CM-iPSC. In conclusion, CM-iPSC recapitulated the LQTS2 phenotype and our findings suggest that the R534C mutation in KCNH2 leads to a channel trafficking defect to the plasma membrane.

scholarly journals From patient-specific induced pluripotent stem cells to clinical translation in long QT syndrome Type 2

2019 ◽  
Vol 40 (23) ◽  
pp. 1832-1836 ◽  
Author(s):  
Peter J Schwartz ◽  
Massimiliano Gnecchi ◽  
Federica Dagradi ◽  
Silvia Castelletti ◽  
Gianfranco Parati ◽  
...  
Keyword(s):  
Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Long Qt Syndrome ◽  
Pluripotent Stem Cells ◽  
Patient Specific ◽  
Syndrome Type ◽  
Long Qt ◽  
Qt Syndrome ◽  
Induced Pluripotent

scholarly journals Promise and Potential Peril With Lumacaftor for the Trafficking Defective Type 2 Long-QT Syndrome-Causative Variants, p.G604S, p.N633S, and p.R685P, Using Patient-Specific Re-Engineered Cardiomyocytes

2020 ◽  
Vol 13 (5) ◽  
pp. 466-475
Author(s):  
Bailey J. O’Hare ◽  
C.S. John Kim ◽  
Samantha K. Hamrick ◽  
Dan Ye ◽  
David J. Tester ◽  
...  
Keyword(s):  
Long Qt Syndrome ◽  
Induced Pluripotent Stem Cell ◽  
Patient Specific ◽  
Delayed Rectifier ◽  
Long Qt ◽  
Novel Therapy ◽  
Channel Trafficking ◽  
K Current ◽  
Qt Syndrome

Background: The KCNH2 -encoded Kv11.1 hERG (human ether-a-go-go related gene) potassium channel is a critical regulator of cardiomyocyte action potential duration (APD). The majority of type 2 long-QT syndrome (LQT2) stems from trafficking defective KCNH2 mutations. Recently, Food and Drug Administration-approved cystic fibrosis protein trafficking chaperone, lumacaftor, has been proposed as novel therapy for LQT2. Here, we test the efficacy of lumacaftor treatment in patient-specific induced pluripotent stem cell-cardiomyocytes (iPSC-CMs) derived from 2 patients with known LQT2 trafficking defective mutations and a patient with novel KCNH2 variant, p.R685P. Methods: Patient-specific iPSC-CM models of KCNH2-G604S, KCNH2-N633S, and KCNH2-R685P were generated from 3 unrelated patients diagnosed with severe LQT2 (rate-corrected QT>500 ms). Lumacaftor efficacy was also tested by ANEPPS, FluoVolt, and ArcLight voltage dye-based APD90 measurements. Results: All 3 mutations were hERG trafficking defective in iPSC-CMs. While lumacaftor treatment failed to rescue the hERG trafficking defect in TSA201 cells, lumacaftor rescued channel trafficking for all mutations in the iPSC-CM model. All 3 mutations conferred a prolonged APD90 compared with control. While lumacaftor treatment rescued the phenotype of KCNH2-N633S and KCNH2-R685P, lumacaftor paradoxically prolonged the APD90 in KCNH2-G604S iPSC-CMs. Lumacaftor-mediated APD90 rescue was affected by rapidly activating delayed rectifier K+ current blocker consistent with the increase of rapidly activating delayed rectifier K+ current by lumacaftor is the underlying mechanism of the LQT2 rescue. Conclusions: While lumacaftor is an effective hERG channel trafficking chaperone and may be therapeutic for LQT2, we urge caution. Without understanding the functionality of the mutant channel to be rescued, lumacaftor therapy could be harmful.

scholarly journals Elucidating arrhythmogenic mechanisms of long-QT syndrome CALM1-F142L mutation in patient-specific induced pluripotent stem cell-derived cardiomyocytes

2017 ◽  
Vol 113 (5) ◽  
pp. 531-541 ◽  
Author(s):  
Marcella Rocchetti ◽  
Luca Sala ◽  
Lisa Dreizehnter ◽  
Lia Crotti ◽  
Daniel Sinnecker ◽  
...  
Keyword(s):  
Stem Cell ◽  
Long Qt Syndrome ◽  
Pluripotent Stem Cell ◽  
Induced Pluripotent Stem Cell ◽  
Patient Specific ◽  
Long Qt ◽  
Qt Syndrome ◽  
Induced Pluripotent

scholarly journals Patient-Specific Induced Pluripotent Stem-Cell Models for Long-QT Syndrome

2010 ◽  
Vol 363 (15) ◽  
pp. 1397-1409 ◽  
Author(s):  
Alessandra Moretti ◽  
Milena Bellin ◽  
Andrea Welling ◽  
Christian Billy Jung ◽  
Jason T. Lam ◽  
...  
Keyword(s):  
Stem Cell ◽  
Long Qt Syndrome ◽  
Pluripotent Stem Cell ◽  
Induced Pluripotent Stem Cell ◽  
Patient Specific ◽  
Cell Models ◽  
Long Qt ◽  
Qt Syndrome ◽  
Induced Pluripotent ◽  
Stem Cell Models

scholarly journals Generation of human induced pluripotent stem cell line from a patient with a long QT syndrome type 2

2016 ◽  
Vol 16 (2) ◽  
pp. 304-307 ◽  
Author(s):  
Azra Fatima ◽  
Dina Ivanyuk ◽  
Stefan Herms ◽  
Stefanie Heilmann-Heimbach ◽  
Orla O'Shea ◽  
...  
Keyword(s):  
Stem Cell ◽  
Long Qt Syndrome ◽  
Pluripotent Stem Cell ◽  
Induced Pluripotent Stem Cell ◽  
Syndrome Type ◽  
Stem Cell Line ◽  
Long Qt ◽  
Qt Syndrome ◽  
Induced Pluripotent

Development of a Patient-Specific p.D85N-KCNE1 Induced Pluripotent Stem Cell-Derived Cardiomyocyte Model for Drug-Induced Long QT Syndrome

2021 ◽  
Author(s):  
Maengjo Kim ◽  
Dan Ye ◽  
CS John Kim ◽  
Wei Zhou ◽  
David J. Tester ◽  
...  
Keyword(s):  
Stem Cell ◽  
Long Qt Syndrome ◽  
Pluripotent Stem Cell ◽  
Induced Pluripotent Stem Cell ◽  
Common Variant ◽  
Patient Specific ◽  
Long Qt ◽  
Drug Induced ◽  
Qt Syndrome ◽  
Induced Pluripotent

Background - Prior epidemiological studies demonstrated that the p.D85N-KCNE1 common variant reduces repolarization reserve and predisposes to drug-induced QT prolongation/torsades de pointes. We sought to develop a cellular model for drug-induced long QT syndrome (DI-LQTS) using a patient-specific induced pluripotent stem cell-derived cardiomyocyte (iPSC-CM). Methods - p.D85N-KCNE1 iPSCs were generated from a 23-year-old female with an exaggerated QTc response to metoclopramide (ΔQTc of 160 ms). CRISPR/Cas9 technology was used to generate "gene-corrected" isogenic iPSCs. Field potential duration (FPD) and action potential duration (APD) were measured from iPSC-CMs. Results - At baseline, p.D85N-KCNE1 iPSC-CMs displayed significantly longer FPD (281 ± 15 ms, n=13 vs. 223 ± 8.6 ms, n=14, p<0.01) and APD 90 (579 ± 22 ms, n=24 vs. 465 ± 33 ms, n=26, p<0.01) than isogenic-control iPSC-CMs. Dofetilide at a concentration of 2nM increased significantly FPD (379 ± 20 ms, n=13, p<0.01) and APD 90 (666 ± 11 ms, n=46, p<0.01) in p.D85N-KCNE1 iPSC-CMs, but not in isogenic-control. The effect of dofetilide on APD 90 (616 ± 54 ms, n=7 vs. 526 ± 54 ms, n=10, p<0.05) was confirmed by Patch-clamp. Interestingly, treatment of p.D85N-KCNE1 iPSC-CMs with estrogen at a concentration of 1nM exaggerated further dofetilide-induced APD 90 prolongation (696 ± 9 ms, n=81, p<0.01) and caused more early afterdepolarizations (EADs) (11.7%) compared to isogenic control (APD 90 : 618 ± 8 ms, n=115 and EADs: 2.6%, p<0.05) Conclusions - This iPSC-CM study provides further evidence that the p.D85N-KCNE1 common variant in combination with environmental factors such as QT prolonging drugs and female sex is pro-arrhythmic.

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