TY - JOUR A1 - Haack, Timm A1 - Abdelilah-Seyfried, Salim T1 - The force within: endocardial development, mechanotransduction and signalling during cardiac morphogenesis JF - Development : Company of Biologists N2 - Endocardial cells are cardiac endothelial cells that line the interior of the heart tube. Historically, their contribution to cardiac development has mainly been considered from a morphological perspective. However, recent studies have begun to define novel instructive roles of the endocardium, as a sensor and signal transducer of biophysical forces induced by blood flow, and as an angiocrine signalling centre that is involved in myocardial cellular morphogenesis, regeneration and reprogramming. In this Review, we discuss how the endocardium develops, how endocardial-myocardial interactions influence the developing embryonic heart, and how the dysregulation of blood flowresponsive endocardial signalling can result in pathophysiological changes. KW - Endocardium KW - Cardiac development KW - Hemodynamics KW - Bmp KW - Kruppel-like factor 2 KW - Vegf KW - Mechanotransduction KW - Zebrafish KW - Mouse Y1 - 2016 U6 - https://doi.org/10.1242/dev.131425 SN - 0950-1991 SN - 1477-9129 VL - 143 SP - 373 EP - 386 PB - Company of Biologists Limited CY - Cambridge ER - TY - JOUR A1 - Muench, Juliane A1 - Grivas, Dimitrios A1 - Gonzalez-Rajal, Alvaro A1 - Torregrosa-Carrion, Rebeca A1 - de la Pompa, José Luis T1 - Notch signalling restricts inflammation and serpine1 expression in the dynamic endocardium of the regenerating zebrafish heart JF - Development : Company of Biologists N2 - The zebrafish heart regenerates after ventricular damage through a process involving inflammation, fibrotic tissue deposition/removal and myocardial regeneration. Using 3D whole-mount imaging, we reveal a highly dynamic endocardium during cardiac regeneration, including changes in cell morphology, behaviour and gene expression. These events lay the foundation for an initial expansion of the endocardium that matures to form a coherent endocardial structure within the injury site. We studied two important endocardial molecules, Serpine1 and Notch, which are implicated in different aspects of endocardial regeneration. Notch signalling regulates developmental gene expression and features of endocardial maturation. Also, Notch manipulation interferes with attenuation of the inflammatory response and cardiomyocyte proliferation and dedifferentiation. serpine1 is strongly expressed very early in the wound endocardium, with decreasing expression at later time points. serpine1 expression persists in Notch-abrogated hearts, via what appears to be a conserved mechanism. Functional inhibition studies show that Serpine1 controls endocardial maturation and proliferation and cardiomyocyte proliferation. Thus, we describe a highly dynamic endocardium in the regenerating zebrafish heart, with two key endocardial players, Serpine1 and Notch signalling, regulating crucial regenerative processes. KW - Heart regeneration KW - Endocardium KW - Myocardium KW - Signalling KW - Serpine1 KW - Notch Y1 - 2017 U6 - https://doi.org/10.1242/dev.143362 SN - 0950-1991 SN - 1477-9129 VL - 144 SP - 1425 EP - 1440 PB - Company of Biologists Limited CY - Cambridge ER -