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Atrial Fibrillation Related Titin Truncation Is Associated With Atrial Myopathy in Patient-Derived Induced Pluripotent Stem Cell Disease Models

delete2025-02-01
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PRE
AI
K
Kate Huang
M
Mishal Ashraf
L
Leili Rohani
Y
Yinhan Luo
A
Ardin Sacayanan
H
Haojun Huang
A
Anne Haegert
S
Stanislav Volik
F
Funda Sar
S
Stéphane LeBihan
J
Janet Liew
P
Peter H. Backx
J
Jason D. Roberts
G
Glen F. Tibbits
J
Jared M. Churko
S
Shubhayan Sanatani
C
Colin C. Collins
L
Liam R. Brunham
Z
Zachary Laksman *
DOI:10.1161/CIRCGEN.123.004412delete
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Abstract

Abstract

En 中文
BACKGROUND:Protein-truncating mutations in the titin gene are associated with increased risk of atrial fibrillation. However, little is known about the underlying pathophysiology.METHODS:We identified a heterozygous titin truncating variant (TTNtv) in a patient with unexplained early onset atrial fibrillation and normal ventricular function. We generated patient-specific atrial- and ventricular-like induced pluripotent stem cell-derived cardiomyocytes and engineered heart tissue to evaluate the impact of the TTNtv on electrophysiology, sarcomere structure, contractility, and gene expression.RESULTS:We demonstrate that the TTNtv increases susceptibility to pacing-induced arrhythmia, promotes sarcomere disorganization, and reduces contractile force in atrial induced pluripotent stem cell-derived cardiomyocytes compared with their CRISPR/Cas9-corrected isogenic controls. In ventricular induced pluripotent stem cell-derived cardiomyocytes, this variant was associated with abnormal electrophysiology and sarcomere organization without a reduction in contractile force compared with their isogenic controls. RNA-sequencing revealed an upregulation of cell adhesion and extracellular matrix genes in the presence of the TTNtv for both atrial and ventricular engineered heart tissues.CONCLUSIONS:In a patient with unexplained atrial fibrillation, induced pluripotent stem cell-derived cardiomyocytes with a TTNtv showed structural and electrophysiological abnormalities in both atrial and ventricular models, while only atrial engineered heart tissues demonstrated reduced contractility. The observed chamber-specific effect suggests that structural disorganization and reduced contractile function may be associated with atrial myopathy in the presence of truncated titin.
Keywords:
arrhythmias, cardiac
atrial fibrillation
connectin
induced pluripotent stem cells
sarcomeres

Journal

Circulation-Genomic and Precision Medicine cover
Circulation-Genomic and Precision Medicine
IF:
5.5
Papers:
684
Citations:
2.4K

Organization

S
Simon Fraser University
Scholars:
1.0W
Papers: 1.0W
Citations: 1.4W
Y
york university - canada
Scholars:
8.1K
Papers: 8.9K
Citations: 10
U
University of British Columbia
Scholars:
6.8W
Papers: 6.1W
Citations: 8.6W
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