Shortening of the elastic tandem immunoglobulin segment of titin leads to diastolic dysfunction.
Circulation
; 128(1): 19-28, 2013 Jul 02.
Article
em En
| MEDLINE
| ID: mdl-23709671
ABSTRACT
BACKGROUND:
Diastolic dysfunction is a poorly understood but clinically pervasive syndrome that is characterized by increased diastolic stiffness. Titin is the main determinant of cellular passive stiffness. However, the physiological role that the tandem immunoglobulin (Ig) segment of titin plays in stiffness generation and whether shortening this segment is sufficient to cause diastolic dysfunction need to be established. METHODS ANDRESULTS:
We generated a mouse model in which 9 Ig-like domains (Ig3-Ig11) were deleted from the proximal tandem Ig segment of the spring region of titin (IG KO). Exon microarray analysis revealed no adaptations in titin splicing, whereas novel phospho-specific antibodies did not detect changes in titin phosphorylation. Passive myocyte stiffness was increased in the IG KO, and immunoelectron microscopy revealed increased extension of the remaining titin spring segments as the sole likely underlying mechanism. Diastolic stiffness was increased at the tissue and organ levels, with no consistent changes in extracellular matrix composition or extracellular matrix-based passive stiffness, supporting a titin-based mechanism for in vivo diastolic dysfunction. Additionally, IG KO mice have a reduced exercise tolerance, a phenotype often associated with diastolic dysfunction.CONCLUSIONS:
Increased titin-based passive stiffness is sufficient to cause diastolic dysfunction with exercise intolerance.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Quinases
/
Imunoglobulinas
/
Diástole
/
Insuficiência Cardíaca Diastólica
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Circulation
Ano de publicação:
2013
Tipo de documento:
Article
País de afiliação:
Estados Unidos