Regulation of titin-based cardiac stiffness by unfolded domain oxidation (UnDOx).
Proc Natl Acad Sci U S A
; 117(39): 24545-24556, 2020 09 29.
Article
em En
| MEDLINE
| ID: mdl-32929035
ABSTRACT
The relationship between oxidative stress and cardiac stiffness is thought to involve modifications to the giant muscle protein titin, which in turn can determine the progression of heart disease. In vitro studies have shown that S-glutathionylation and disulfide bonding of titin fragments could alter the elastic properties of titin; however, whether and where titin becomes oxidized in vivo is less certain. Here we demonstrate, using multiple models of oxidative stress in conjunction with mechanical loading, that immunoglobulin domains preferentially from the distal titin spring region become oxidized in vivo through the mechanism of unfolded domain oxidation (UnDOx). Via oxidation type-specific modification of titin, UnDOx modulates human cardiomyocyte passive force bidirectionally. UnDOx also enhances titin phosphorylation and, importantly, promotes nonconstitutive folding and aggregation of unfolded domains. We propose a mechanism whereby UnDOx enables the controlled homotypic interactions within the distal titin spring to stabilize this segment and regulate myocardial passive stiffness.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas Quinases
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Estresse Oxidativo
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Miócitos Cardíacos
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Miocárdio
Limite:
Animals
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article