Molecular characterization of the calcium release channel deficiency syndrome

Autor: Michael J. Ackerman, Joel Temple, Hannah M. Bombei, Luis A. Ochoa Nunez, Ian H. Law, CS John Kim, Bailey J. O’Hare, Dan Ye, Carla M Haglund-Turnquist, David J. Tester, Dianne L. Atkins, Samantha K. Hamrick, Kristi K Fitzgerald
Rok vydání: 2020
Předmět:
Male
0301 basic medicine
medicine.medical_specialty
Adolescent
Induced Pluripotent Stem Cells
Cardiology
chemistry.chemical_element
Calcium
Catecholaminergic polymorphic ventricular tachycardia
Ryanodine receptor 2
Afterdepolarization
03 medical and health sciences
0302 clinical medicine
Nadolol
Gene Duplication
Internal medicine
Gene duplication
Genetics
medicine
Humans
Myocytes
Cardiac
Genetic variation
Child
Flecainide
Chemistry
Ryanodine receptor
Homozygote
Cell Differentiation
Ryanodine Receptor Calcium Release Channel
General Medicine
Cardiovascular disease
musculoskeletal system
medicine.disease
Pedigree
Phenotype
030104 developmental biology
Endocrinology
Case-Control Studies
Child
Preschool
Ion channels
030220 oncology & carcinogenesis
Tachycardia
Ventricular
cardiovascular system
Female
tissues
Research Article
medicine.drug
Zdroj: JCI Insight
ISSN: 2379-3708
Popis: We identified a potentially novel homozygous duplication involving the promoter region and exons 1–4 of the gene encoding type 2 cardiac ryanodine receptor (RYR2) that is responsible for highly penetrant, exertion-related sudden deaths/cardiac arrests in the Amish community without an overt phenotype to suggest RYR2-mediated catecholaminergic polymorphic ventricular tachycardia (CPVT). Homozygous RYR2 duplication (RYR2-DUP) induced pluripotent stem cell cardiomyocytes (iPSC-CMs) were generated from 2 unrelated patients. There was no difference in baseline Ca2+ handling measurements between WT-iPSC-CM and RYR2-DUP-iPSC-CM lines. However, compared with WT-iPSC-CMs, both patient lines demonstrated a dramatic reduction in caffeine-stimulated and isoproterenol-stimulated (ISO-stimulated) Ca2+ transient amplitude, suggesting RyR2 loss of function. There was a greater than 50% reduction in RYR2 transcript/RyR2 protein expression in both patient iPSC-CMs compared with WT. Delayed afterdepolarization was observed in the RYR2-DUP-iPSC-CMs but not in the WT-iPSC-CMs. Compared with WT-iPSC-CMs, there was significantly elevated arrhythmic activity in the RYR2-DUP-iPSC-CMs in response to ISO. Nadolol, propranolol, and flecainide reduced erratic activity by 8.5-fold, 6.8-fold, and 2.4-fold, respectively, from ISO challenge. Unlike the gain-of-function mechanism observed in RYR2-mediated CPVT, the homozygous multiexon duplication precipitated a dramatic reduction in RYR2 transcription and RyR2 protein translation, a loss of function in calcium handling, and a calcium-induced calcium release apparatus that is insensitive to catecholamines and caffeine.
Molecular and functional characterization of the calcium release channel deficiency syndrome in patient-specific induced pluripotent stem cell-cardiomyocytes.
Databáze: OpenAIRE
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