TY  - JOUR
A1  - Merks, Anne Margarete
A1  - Swinarski, Marie
A1  - Meyer, Alexander Matthias
A1  - Müller, Nicola Victoria
A1  - Özcan, Ismail
A1  - Donat, Stefan
A1  - Burger, Alexa
A1  - Gilbert, Stephen
A1  - Mosimann, Christian
A1  - Abdelilah-Seyfried, Salim
A1  - Panakova, Daniela
T1  - Planar cell polarity signalling coordinates heart tube remodelling through tissue-scale polarisation of actomyosin activity
JF  - Nature Communications
N2  - Development of a multiple-chambered heart from the linear heart tube is inherently linked to cardiac looping. Although many molecular factors regulating the process of cardiac chamber ballooning have been identified, the cellular mechanisms underlying the chamber formation remain unclear. Here, we demonstrate that cardiac chambers remodel by cell neighbour exchange of cardiomyocytes guided by the planar cell polarity (PCP) pathway triggered by two non-canonical Wnt ligands, Wnt5b and Wnt11. We find that PCP signalling coordinates the localisation of actomyosin activity, and thus the efficiency of cell neighbour exchange. On a tissue-scale, PCP signalling planar-polarises tissue tension by restricting the actomyosin contractility to the apical membranes of outflow tract cells. The tissue-scale polarisation of actomyosin contractility is required for cardiac looping that occurs concurrently with chamber ballooning. Taken together, our data reveal that instructive PCP signals couple cardiac chamber expansion with cardiac looping through the organ-scale polarisation of actomyosin-based tissue tension.
Y1  - 2018
U6  - https://doi.org/10.1038/s41467-018-04566-1
SN  - 2041-1723
VL  - 9
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Donat, Stefan
A1  - Lourenco, Marta Sofia Rocha
A1  - Paolini, Alessio
A1  - Otten, Cecile
A1  - Renz, Marc
A1  - Abdelilah-Seyfried, Salim
T1  - Heg1 and Ccm1/2 proteins control endocardial mechanosensitivity during zebrafish valvulogenesis
JF  - eLife
N2  - Endothelial cells respond to different levels of fluid shear stress through adaptations of their mechanosensitivity. Currently, we lack a good understanding of how this contributes to sculpting of the cardiovascular system. Cerebral cavernous malformation (CCM) is an inherited vascular disease that occurs when a second somatic mutation causes a loss of CCM1/KRIT1, CCM2, or CCM3 proteins. Here, we demonstrate that zebrafish Krit1 regulates the formation of cardiac valves. Expression of heg1, which encodes a binding partner of Krit1, is positively regulated by blood-flow. In turn, Heg1 stabilizes levels of Krit1 protein, and both Heg1 and Krit1 dampen expression levels of klf2a, a major mechanosensitive gene. Conversely, loss of Krit1 results in increased expression of klf2a and notch1b throughout the endocardium and prevents cardiac valve leaflet formation. Hence, the correct balance of blood-flow-dependent induction and Krit1 protein mediated repression of klf2a and notch1b ultimately shapes cardiac valve leaflet morphology.
Y1  - 2018
U6  - https://doi.org/10.7554/eLife.28939
SN  - 2050-084X
VL  - 7
PB  - eLife Sciences Publications
CY  - Cambridge
ER  -