Transforming growth factor ß receptor inhibition prevents ventricular fibrosis in a mouse model of progressive cardiac conduction disease.
Cardiovasc Res
; 113(5): 464-474, 2017 Apr 01.
Article
em En
| MEDLINE
| ID: mdl-28339646
ABSTRACT
AIMS:
Loss-of-function mutations in SCN5A, the gene encoding NaV1.5 channel, have been associated with inherited progressive cardiac conduction disease (PCCD). We have proposed that Scn5a heterozygous knock-out (Scn5a+/-) mice, which are characterized by ventricular fibrotic remodelling with ageing, represent a model for PCCD. Our objectives were to identify the molecular pathway involved in fibrosis development and prevent its activation. METHODS ANDRESULTS:
Our study shows that myocardial interstitial fibrosis occurred in Scn5a+/- mice only after 45 weeks of age. Fibrosis was triggered by transforming growth factor ß (TGF-ß) pathway activation. Younger Scn5a+/- mice were characterized by a higher connexin 43 expression than wild-type (WT) mice. After the age of 45 weeks, connexin 43 expression decreased in both WT and Scn5a+/- mice, although the decrease was larger in Scn5a+/- mice. Chronic inhibition of cardiac sodium current with flecainide (50 mg/kg/day p.o) in WT mice from the age of 6 weeks to the age of 60 weeks did not lead to TGF-ß pathway activation and fibrosis. Chronic inhibition of TGF-ß receptors with GW788388 (5 mg/kg/day p.o.) in Scn5a+/- mice from the age of 45 weeks to the age of 60 weeks prevented the occurrence of fibrosis. However, current data could not detect reduction in QRS duration with GW788388.CONCLUSION:
Myocardial fibrosis secondary to a loss of NaV1.5 is triggered by TGF-ß signalling pathway. Those events are more likely secondary to the decreased NaV1.5 sarcolemmal expression rather than the decreased Na+ current per se. TGF-ß receptor inhibition prevents age-dependent development of ventricular fibrosis in Scn5a+/- mouse.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Arritmias Cardíacas
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Pirazóis
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Benzamidas
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Receptores de Fatores de Crescimento Transformadores beta
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Remodelação Ventricular
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Sistema de Condução Cardíaco
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Ventrículos do Coração
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Cardiomiopatias
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article