In:
Circulation Research, Ovid Technologies (Wolters Kluwer Health), Vol. 110, No. 10 ( 2012-05-11), p. 1303-1310
Kurzfassung:
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 and Results: Distribution of Islet-1 + cells in adult heart was investigated using gene targeted mice with nuclear β-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.
Materialart:
Online-Ressource
ISSN:
0009-7330
,
1524-4571
DOI:
10.1161/CIRCRESAHA.111.259630
Sprache:
Englisch
Verlag:
Ovid Technologies (Wolters Kluwer Health)
Publikationsdatum:
2012
ZDB Id:
1467838-X
