Transient titin-dependent ventricular defects during development lead to adult atrial arrhythmia and impaired contractility.
iScience
; 27(7): 110395, 2024 Jul 19.
Article
em En
| MEDLINE
| ID: mdl-39100923
ABSTRACT
Developmental causes of the most common arrhythmia, atrial fibrillation (AF), are poorly defined, with compensation potentially masking arrhythmic risk. Here, we delete 9 amino acids (Δ9) within a conserved domain of the giant protein titin's A-band in zebrafish and human-induced pluripotent stem cell-derived atrial cardiomyocytes (hiPSC-aCMs). We find that ttna Δ9/Δ9 zebrafish embryos' cardiac morphology is perturbed and accompanied by reduced functional output, but ventricular function recovers within days. Despite normal ventricular function, ttna Δ9/Δ9 adults exhibit AF and atrial myopathy, which are recapitulated in TTN Δ9/Δ9-hiPSC-aCMs. Additionally, action potential is shortened and slow delayed rectifier potassium current (I Ks) is increased due to aberrant atrial natriuretic peptide (ANP) levels. Strikingly, suppression of I Ks in both models prevents AF and improves atrial contractility. Thus, a small internal deletion in titin causes developmental abnormalities that increase the risk of AF via ion channel remodeling, with implications for patients who harbor disease-causing variants in sarcomeric proteins.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
IScience
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Estados Unidos