Changes in ion channel expression and function associated with cardiac arrhythmogenic remodeling by Sorbs2.
Biochim Biophys Acta Mol Basis Dis
; 1867(12): 166247, 2021 12 01.
Article
em En
| MEDLINE
| ID: mdl-34487812
ABSTRACT
The Sorbin and SH3 domain-containing protein 2 (Sorbs2) is an important component of cardiomyocyte sarcomere. It has been recently reported that loss of Sorbs2 is causally associated with arrhythmogenic cardiomyopathy in human. However, the ionic mechanisms leading to cardiac arrhythmogenesis by Sorbs2 deficiency are unknown. In this study, we hypothesized that Sorbs2 plays an important role in regulating cardiac ion channel expression and function. Using electrophysiological and molecular biological approaches, we found that the Sorbs2 knockout (KO) mice progressively developed cardiac structural and electrical remodeling as early as 1 to 2 months of age and died prematurely at 5 to 7 months of age. Electrocardiographic recordings showed that Sorbs2 KO mice had conduction delays, spontaneous ventricular extrasystoles and polymorphic ventricular tachyarrhythmia. Intracellular recordings revealed abnormal action potentials with depolarized resting potential, reduced upstroke velocity, prolonged repolarization, and effective refractory period in the ventricular preparations of Sorbs2 KO mice. Patch clamp experiments demonstrated that Sorbs2 KO mice displayed distinct abnormalities in the expression and function of cardiac ion channels, including those of the voltage-gated Na+ channels, L-type Ca2+ channels, the voltage-gated K+ channels and the inward-rectifier K+ channels. Moreover, Sorbs2 physically interacted with the RNAs and/or proteins of important cardiac ion channels and directly regulated their expression in vitro. Our results indicate that Sorbs2 plays a pivotal role in the regulation of cardiac channel physiology. Loss of Sorbs2 promotes cardiac ion channelopathies and life-threatening arrhythmias.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Arritmias Cardíacas
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Proteínas de Ligação a RNA
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Proteínas Adaptadoras de Transdução de Sinal
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Remodelamento Atrial
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Canais Iônicos
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
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Humans
Idioma:
En
Revista:
Biochim Biophys Acta Mol Basis Dis
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Estados Unidos