ZFIN ID: ZDB-PUB-161208-1
In Vivo Visualization of Cardiomyocyte Apicobasal Polarity Reveals Epithelial to Mesenchymal-like Transition during Cardiac Trabeculation
Jiménez-Amilburu, V., Rasouli, S.J., Staudt, D.W., Nakajima, H., Chiba, A., Mochizuki, N., Stainier, D.Y.
Date: 2016
Source: Cell Reports 17: 2687-2699 (Journal)
Registered Authors: Mochizuki, Naoki, Nakajima, Hiroyuki, Stainier, Didier, Staudt, David
Keywords: EMT, apical constriction, apicobasal polarity, cardiomyocyte depolarization, live imaging, trabeculation, zebrafish
MeSH Terms: Animals; Animals, Genetically Modified; Cell Polarity/genetics; Epithelial-Mesenchymal Transition/genetics*; Humans (all 18) expand
PubMed: 27926871 Full text @ Cell Rep.
FIGURES   (current status)
Despite great strides in understanding cardiac trabeculation, many mechanistic aspects remain unclear. To elucidate how cardiomyocyte shape changes are regulated during this process, we engineered transgenes to label their apical and basolateral membranes. Using these tools, we observed that compact-layer cardiomyocytes are clearly polarized while delaminating cardiomyocytes have lost their polarity. The apical transgene also enabled the imaging of cardiomyocyte apical constriction in real time. Furthermore, we found that Neuregulin signaling and blood flow/cardiac contractility are required for cardiomyocyte apical constriction and depolarization. Notably, we observed the activation of Notch signaling in cardiomyocytes adjacent to those undergoing apical constriction, and we showed that this activation is positively regulated by Neuregulin signaling. Inhibition of Notch signaling did not increase the percentage of cardiomyocytes undergoing apical constriction or of trabecular cardiomyocytes. These studies provide information about cardiomyocyte polarization and enhance our understanding of the complex mechanisms underlying ventricular morphogenesis and maturation.