Localization of Islet-1-positive cells in the healthy and infarcted adult murine heart.
Circ Res
; 110(10): 1303-10, 2012 May 11.
Article
em En
| MEDLINE
| ID: mdl-22427341
ABSTRACT
RATIONALE The transcription factor Islet-1 is a marker of cardiovascular progenitors during embryogenesis. The isolation of Islet-1-positive (Islet-1(+)) cells from early postnatal hearts suggested that Islet-1 also marks cardiac progenitors in adult life. OBJECTIVE:
We investigated the distribution and identity of Islet-1(+) cells in adult murine heart and evaluated whether their number or distribution change with age or after myocardial infarction. METHODS ANDRESULTS:
Distribution of Islet-1(+) cells in adult heart was investigated using gene targeted mice with nuclear ß-galactosidase inserted into the Islet-1 locus. nLacZ-positive cells were only present in 3 regions of the adult heart clusters in the interatrial septum and around the pulmonary veins, scattered within the wall of the great vessels, and a strictly delimited cluster between the right atrium and superior vena cava. Islet-1(+) cells in the first type of clusters coexpressed markers for parasympathetic neurons. Positive cells in the great arteries coexpressed smooth muscle actin and myosin heavy chain, indicating a smooth muscle cell identity. Very few Islet-1(+) cells within the outflow tract expressed the cardiomyocyte marker α-actinin. Islet-1(+) cells in the right atrium coexpressed the sinoatrial node pacemaker cell marker HCN4. Cell number and localization remained unchanged between 1 to 18 months of age. Consistently Islet-1 mRNA was detected in human sinoatrial node. Islet-1(+) cells could not be detected in the infarct zone 2 to 28 days after myocardial infarction, aside from 10 questionable cells in 1/13 hearts.CONCLUSIONS:
Our results identify Islet-1 as a novel marker of the adult sinoatrial node and do not provide evidence for Islet-1(+) cells to serve as cardiac progenitors.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Nó Sinoatrial
/
Fatores de Transcrição
/
Proteínas com Homeodomínio LIM
/
Infarto do Miocárdio
/
Miocárdio
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Circ Res
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Alemanha