The juxta-cardiac field represents a common progenitor field that can contribute to cardiomyocytes and the epicardium
Presented by: Richard Tyser
Presentation time:
The cardiac crescent is the first morphologically recognizable heart structure in the developing embryo, arising from subsets of mesoderm-derived cardiovascular progenitors. The aim of this study was to characterise the progenitor cell types that constitute the forming cardiac crescent at both an anatomical and transcriptional level. This analysis revealed an anatomically distinct region of progenitors, the Juxta-Cardiac Field (JCF), which could contribute to both cardiomyocytes and epicardium.
We used manual micro-dissection to isolate the cardiac region of mouse embryos, from 6 different stages of cardiac crescent to linear heart tube development and performed SMART-Seq2 single cell RNA sequencing. This enabled us to transcriptionally define the cardiac progenitor populations in this region, including the First and Second Heart Fields. To identify the anatomical locations of these cell populations at single cell resolution, we used whole-mount immunohistochemistry, multiplexed fluorescence in situ hybridization and high-resolution volume imaging of combinations of markers. This revealed the discrete anatomical location of these transcriptional defined progenitor types and highlighted the spatially ordered maturation of cardiomyocytes. It also identified a population of progenitor cells located at the rostral border of the cardiac crescent that we termed the Juxta-Cardiac Field (JCF). Using single-cell resolution time-lapse imaging and genetic lineage-labelling, we established that the JCF could contribute to both cardiomyocytes as well as the proepicardium.
By combining multiple experimental approaches, we have been able to gain novel insight into the spatiotemporal differentiation of cardiac progenitors during heart formation. Furthermore, by identifying the juxta-cardiac field, our work widens the cardiac progenitor region and identifies the earliest progenitors of the proepicardium. This study will contribute to a better understanding of the origin of congenital cardiac defects as well as provide basic insights for informing regenerative approaches to treat heart disease.
We used manual micro-dissection to isolate the cardiac region of mouse embryos, from 6 different stages of cardiac crescent to linear heart tube development and performed SMART-Seq2 single cell RNA sequencing. This enabled us to transcriptionally define the cardiac progenitor populations in this region, including the First and Second Heart Fields. To identify the anatomical locations of these cell populations at single cell resolution, we used whole-mount immunohistochemistry, multiplexed fluorescence in situ hybridization and high-resolution volume imaging of combinations of markers. This revealed the discrete anatomical location of these transcriptional defined progenitor types and highlighted the spatially ordered maturation of cardiomyocytes. It also identified a population of progenitor cells located at the rostral border of the cardiac crescent that we termed the Juxta-Cardiac Field (JCF). Using single-cell resolution time-lapse imaging and genetic lineage-labelling, we established that the JCF could contribute to both cardiomyocytes as well as the proepicardium.
By combining multiple experimental approaches, we have been able to gain novel insight into the spatiotemporal differentiation of cardiac progenitors during heart formation. Furthermore, by identifying the juxta-cardiac field, our work widens the cardiac progenitor region and identifies the earliest progenitors of the proepicardium. This study will contribute to a better understanding of the origin of congenital cardiac defects as well as provide basic insights for informing regenerative approaches to treat heart disease.