The α11 integrin mediates fibroblast-extracellular matrix-cardiomyocyte interactions in health and disease.
Am J Physiol Heart Circ Physiol
; 311(1): H96-H106, 2016 07 01.
Article
em En
| MEDLINE
| ID: mdl-27199132
ABSTRACT
Excessive cardiac interstitial fibrosis impairs normal cardiac function. We have shown that the α11ß1 (α11) integrin mediates fibrotic responses to glycated collagen in rat myocardium by a pathway involving transforming growth factor-ß. Little is known of the role of the α11 integrin in the developing mammalian heart. Therefore, we examined the impact of deletion of the α11 integrin in wild-type mice and in mice treated with streptozotocin (STZ) to elucidate the role of the α11 integrin in normal cardiac homeostasis and in the pathogenesis of diabetes-related fibrosis. As anticipated, cardiac fibrosis was reduced in α11 integrin knockout mice (α11(-/-); C57BL/6 background) treated with STZ compared with STZ-treated wild-type mice (P < 0.05). Unexpectedly, diastolic function was impaired in both vehicle and STZ-treated α11(-/-) mice, as shown by the decreased minimum rate of pressure change and prolonged time constant of relaxation in association with increased end-diastolic pressure (all P < 0.05 compared with wild-type mice). Accordingly, we examined the phenotype of untreated α11(-/-) mice, which demonstrated a reduced cardiomyocyte cross-sectional cell area and myofibril thickness (all P < 0.05 compared with wild-type mice) and impaired myofibril arrangement. Immunostaining for desmin and connexin 43 showed abnormal intermediate filament organization at intercalated disks and impaired gap-junction development. Overall, deletion of the α11 integrin attenuates cardiac fibrosis in the mammalian mouse heart and reduces ECM formation as a result of diabetes. Furthermore, α11 integrin deletion impairs cardiac function and alters cardiomyocyte morphology. These findings shed further light on the poorly understood interaction between the fibroblast-cardiomyocyte and the ECM.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Miócitos Cardíacos
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Cadeias alfa de Integrinas
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Matriz Extracelular
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Cardiomiopatias Diabéticas
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Fibroblastos
Idioma:
En
Revista:
Am J Physiol Heart Circ Physiol
Assunto da revista:
CARDIOLOGIA
/
FISIOLOGIA
Ano de publicação:
2016
Tipo de documento:
Article