How Are Coronary Arteries Made?

Most coronary vessels in the ventricular free walls are derived from sinus venosus endothelial cells, rather than the ventricular endocardium as once thought.

AsianScientist (May 6, 2016) – Taking advantage of genetic lineage tracing, Professor Zhou Bin’s lab at the Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences found that most coronary vessels in the ventricular free walls are derived from sinus venosus endothelial cells, rather than ventricular endocardium.

This finding, published in Circulation Research, reveals the developmental origin of coronary vessels, and provides the basis for studying coronary vessel formation and regeneration after injury.

The developmental origin of coronary arteries has been a long-standing mystery in the cardiovascular field. Studies in the past decade have implicated two major candidate sources: ventricular endocardium and sinus venosus endothelial cells, but there is ongoing controversy over their relative contribution.

Taking advantage of Nfatc1-Cre and other genetic mouse lines which were supposed to specifically label endocardium, the researchers carried out lineage tracing experiments and found that Nfatc1 is not only expressed in endocardium but also in sinus venosus endothelial cells at early embryonic stages.

To specifically label ventricular endocardium, the researchers identified a new gene—Npr3—which is specifically expressed in endocardium but not sinus venosus endothelia. Lineage tracing of ventricular endocardium using Npr3-CreER mouse line reveals that ventricular endocardium minimally contributes to the embryonic coronary vessels in the ventricular free walls. Further study proved that sinus venosus might be the main source for the embryonic coronary vessels in the ventricular free walls.

Endocardial endothelial cells and coronary vascular endothelial cells are two different kinds of endothelial cells with different gene expression profiles. In this study, the researchers isolated these two populations in the embryonic heart and identified arrays of genes that are specifically express in endocardium or coronary vessels. These findings provide the basis for studying coronary vessel formation and regeneration after injury.


The article can be found at: Zhang et al. (2016) Endocardium Minimally Contributes to Coronary Endothelium in the Embryonic Ventricular Free Walls.

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Source: Chinese Academy of Sciences; Photo: Shutterstock.
Disclaimer: This article does not necessarily reflect the views of AsianScientist or its staff.

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