4346 Potential Sudden Unexpected Death in Epilepsy (SUDEP) Biomarkers in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes with DEPDC5 Loss-of-Function
OBJECTIVES/GOALS: Sudden Unexpected Death in Epilepsy (SUDEP) is a leading cause of death in epilepsy patients. This study aims to determine whether cardiac mechanisms contribute to SUDEP in epilepsy patients with variants in DEPDC5, a gene encoding a member of the mTOR GATOR complex, to identify SU...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Cambridge University Press
2020-06-01
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| Series: | Journal of Clinical and Translational Science |
| Online Access: | https://www.cambridge.org/core/product/identifier/S2059866120003118/type/journal_article |
| _version_ | 1811155082603921408 |
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| author | Yanting Zhao Helen Zhang Jack M. Parent Lori L. Isom |
| author_facet | Yanting Zhao Helen Zhang Jack M. Parent Lori L. Isom |
| author_sort | Yanting Zhao |
| collection | DOAJ |
| description | OBJECTIVES/GOALS: Sudden Unexpected Death in Epilepsy (SUDEP) is a leading cause of death in epilepsy patients. This study aims to determine whether cardiac mechanisms contribute to SUDEP in epilepsy patients with variants in DEPDC5, a gene encoding a member of the mTOR GATOR complex, to identify SUDEP biomarkers. METHODS/STUDY POPULATION: SUDEP has been reported in 10% of epilepsy patients with DEPDC5 loss-of-function variants. We used human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) to measure changes in cellular excitability that are known to be substrates for cardiac arrhythmias. CRISPR-derived isogenic DEPDC5 iPSC-CMs and DEPDC5 patient-derived iPSC-CMs were used in this study. Whole-cell patch-clamp was used to measure voltage-gated sodium current (INa) and calcium current (I>Ca) in single iPSC-CMs in voltage-clamp mode; and to measure action potentials (APs) in 3-dimentional iPSC-CM-derived micro-tissues in current-clamp mode. RESULTS/ANTICIPATED RESULTS: CRISPR generated heterozygous deletion of 1 base-pair in the first coding exon of DEPDC5 gene, resulting in a premature stop codon, simulated the variants identified in DEPDC5 epilepsy patients. In CRISPR generated heterozygousDEPDC5 iPSC-CMs, whole-cell voltage-clamp recordings revealed that INa was increased and ICa was reduced compared with isogenic control iPSC-CMs. Whole-cell current-clamp recordings revealed that AP duration at 80% and 90% of repolarization, APD80 and APD90, respectively, were prolonged compared to isogenic control iPSC-CMs. Similar measurements will be performed for iPSC-CMs derived from DEPDC5 patients. DISCUSSION/SIGNIFICANCE OF IMPACT: This study shows that epilepsy patients with non-ion channel gene variants in DEPDC5 have altered CM excitability, which may serve as a substrate for cardiac arrhythmias in DEPDC5 patients. Importantly, this work may allow us to identify biomarkers for SUDEP risk in these patients in the future. CONFLICT OF INTEREST DESCRIPTION: L.L.I. is the recipient of a collaborative research grant from Stoke Therapeutics. |
| first_indexed | 2024-04-10T04:28:12Z |
| format | Article |
| id | doaj.art-26c2667665fd4cb28491923068ee9f7b |
| institution | Directory Open Access Journal |
| issn | 2059-8661 |
| language | English |
| last_indexed | 2024-04-10T04:28:12Z |
| publishDate | 2020-06-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Clinical and Translational Science |
| spelling | doaj.art-26c2667665fd4cb28491923068ee9f7b2023-03-10T08:51:35ZengCambridge University PressJournal of Clinical and Translational Science2059-86612020-06-01410010010.1017/cts.2020.3114346 Potential Sudden Unexpected Death in Epilepsy (SUDEP) Biomarkers in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes with DEPDC5 Loss-of-FunctionYanting Zhao0Helen Zhang1Jack M. Parent2Lori L. Isom3University of Michigan School of MedicineUniversity of MichiganUniversity of MichiganDepartment of Pharmacology, University of MichiganOBJECTIVES/GOALS: Sudden Unexpected Death in Epilepsy (SUDEP) is a leading cause of death in epilepsy patients. This study aims to determine whether cardiac mechanisms contribute to SUDEP in epilepsy patients with variants in DEPDC5, a gene encoding a member of the mTOR GATOR complex, to identify SUDEP biomarkers. METHODS/STUDY POPULATION: SUDEP has been reported in 10% of epilepsy patients with DEPDC5 loss-of-function variants. We used human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) to measure changes in cellular excitability that are known to be substrates for cardiac arrhythmias. CRISPR-derived isogenic DEPDC5 iPSC-CMs and DEPDC5 patient-derived iPSC-CMs were used in this study. Whole-cell patch-clamp was used to measure voltage-gated sodium current (INa) and calcium current (I>Ca) in single iPSC-CMs in voltage-clamp mode; and to measure action potentials (APs) in 3-dimentional iPSC-CM-derived micro-tissues in current-clamp mode. RESULTS/ANTICIPATED RESULTS: CRISPR generated heterozygous deletion of 1 base-pair in the first coding exon of DEPDC5 gene, resulting in a premature stop codon, simulated the variants identified in DEPDC5 epilepsy patients. In CRISPR generated heterozygousDEPDC5 iPSC-CMs, whole-cell voltage-clamp recordings revealed that INa was increased and ICa was reduced compared with isogenic control iPSC-CMs. Whole-cell current-clamp recordings revealed that AP duration at 80% and 90% of repolarization, APD80 and APD90, respectively, were prolonged compared to isogenic control iPSC-CMs. Similar measurements will be performed for iPSC-CMs derived from DEPDC5 patients. DISCUSSION/SIGNIFICANCE OF IMPACT: This study shows that epilepsy patients with non-ion channel gene variants in DEPDC5 have altered CM excitability, which may serve as a substrate for cardiac arrhythmias in DEPDC5 patients. Importantly, this work may allow us to identify biomarkers for SUDEP risk in these patients in the future. CONFLICT OF INTEREST DESCRIPTION: L.L.I. is the recipient of a collaborative research grant from Stoke Therapeutics.https://www.cambridge.org/core/product/identifier/S2059866120003118/type/journal_article |
| spellingShingle | Yanting Zhao Helen Zhang Jack M. Parent Lori L. Isom 4346 Potential Sudden Unexpected Death in Epilepsy (SUDEP) Biomarkers in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes with DEPDC5 Loss-of-Function Journal of Clinical and Translational Science |
| title | 4346 Potential Sudden Unexpected Death in Epilepsy (SUDEP) Biomarkers in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes with DEPDC5 Loss-of-Function |
| title_full | 4346 Potential Sudden Unexpected Death in Epilepsy (SUDEP) Biomarkers in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes with DEPDC5 Loss-of-Function |
| title_fullStr | 4346 Potential Sudden Unexpected Death in Epilepsy (SUDEP) Biomarkers in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes with DEPDC5 Loss-of-Function |
| title_full_unstemmed | 4346 Potential Sudden Unexpected Death in Epilepsy (SUDEP) Biomarkers in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes with DEPDC5 Loss-of-Function |
| title_short | 4346 Potential Sudden Unexpected Death in Epilepsy (SUDEP) Biomarkers in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes with DEPDC5 Loss-of-Function |
| title_sort | 4346 potential sudden unexpected death in epilepsy sudep biomarkers in human induced pluripotent stem cell derived cardiomyocytes with depdc5 loss of function |
| url | https://www.cambridge.org/core/product/identifier/S2059866120003118/type/journal_article |
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