Abstract 20819: Hematopoietic Progenitors are Required for Proper Development of Coronary Vasculature
Introduction: During embryogenesis, hematopoietic cells appear in the myocardium prior to the initiation of coronary formation. However, their role is unknown.
Hypothesis: Here we investigate whether pre-existing hematopoietic cells are required for the formation of coronary vasculature.
Methods: As a model of for hematopoietic cell deficient animals, we used Runx1 knockout embryos and Vav1-cre; R26-DTA embryos, latter of which genetically ablates 2/3 of CD45+ hematopoietic cells.
Results: Both Runx1 knockout embryos and Vav1-cre; R26-DTA embryos revealed disorganized, hypoplastic microvasculature of coronary vessels on section and whole-mount stainings. Furthermore, coronary explant experiments showed that the mouse heart explants from Runx1 and Vav1-cre; R26-DTA embryos exhibited impaired coronary formation ex vivo. Interestingly, in both models it appears that epicardial to mesenchymal transition is adversely affected in the absence of hematopoietic progenitors.
Conclusions: Hematopoietic cells are not merely passively transported via coronary vessel, but substantially involved in the induction of the coronary growth. Our findings suggest a novel mechanism of coronary growth.
Author Disclosures: G. Lluri: None. V. Huang: None. M. Touma: None. A. Nakano: None.
- © 2016 by American Heart Association, Inc.