RATIONALE: The embryonic epicardium plays a crucial role in the formation of the coronary vasculature and in myocardial development, yet the exact contribution of epicardium-derived cells (EPDCs) to the vascular and connective tissue of the heart, and the factors that regulate epicardial differentiation, are insufficiently understood. OBJECTIVE: To define the role of Notch signaling in murine epicardial development. METHODS AND RESULTS: Using in situ hybridization and RT-PCR analyses, we detected expression of a number of Notch receptor and ligand genes in early epicardial development, as well as during formation of coronary arteries. Mice with epicardial deletion of Rbpj, the unique intracellular mediator of Notch signaling, survived to adulthood and exhibited enlarged coronary venous and arterial beds. Using a Tbx18-based genetic lineage tracing system, we show that EPDCs give rise to fibroblasts and coronary smooth muscle cells (SMCs) but not to endothelial cells in the wild type, whereas in Rbpj-deficient embryos EPDCs form and surround the developing arteries but fail to differentiate into SMCs. Conditional activation of Notch signaling results in premature SMC differentiation of epicardial cells and prevents coronary angiogenesis. We further show that Notch signaling regulates, and cooperates with transforming growth factor β signaling in SM differentiation of EPDCs. CONCLUSIONS: Notch signaling is a crucial regulator of SM differentiation of EPDCs, and thus, of formation of a functional coronary system.
RATIONALE: The embryonic epicardium plays a crucial role in the formation of the coronary vasculature and in myocardial development, yet the exact contribution of epicardium-derived cells (EPDCs) to the vascular and connective tissue of the heart, and the factors that regulate epicardial differentiation, are insufficiently understood. OBJECTIVE: To define the role of Notch signaling in murine epicardial development. METHODS AND RESULTS: Using in situ hybridization and RT-PCR analyses, we detected expression of a number of Notch receptor and ligand genes in early epicardial development, as well as during formation of coronary arteries. Mice with epicardial deletion of Rbpj, the unique intracellular mediator of Notch signaling, survived to adulthood and exhibited enlarged coronary venous and arterial beds. Using a Tbx18-based genetic lineage tracing system, we show that EPDCs give rise to fibroblasts and coronary smooth muscle cells (SMCs) but not to endothelial cells in the wild type, whereas in Rbpj-deficient embryos EPDCs form and surround the developing arteries but fail to differentiate into SMCs. Conditional activation of Notch signaling results in premature SMC differentiation of epicardial cells and prevents coronary angiogenesis. We further show that Notch signaling regulates, and cooperates with transforming growth factor β signaling in SM differentiation of EPDCs. CONCLUSIONS: Notch signaling is a crucial regulator of SM differentiation of EPDCs, and thus, of formation of a functional coronary system.
Authors: Thomas Brade; Luna S Pane; Alessandra Moretti; Kenneth R Chien; Karl-Ludwig Laugwitz Journal: Cold Spring Harb Perspect Med Date: 2013-10-01 Impact factor: 6.915
Authors: Anamika Singh; Sindhu Ramesh; Dasan Mary Cibi; Lim Sze Yun; Jun Li; Li Li; Lauren J Manderfield; Eric N Olson; Jonathan A Epstein; Manvendra K Singh Journal: Cell Rep Date: 2016-05-05 Impact factor: 9.423
Authors: Ke Wei; Ramon Díaz-Trelles; Qiaozhen Liu; Marta Diez-Cuñado; Maria-Cecilia Scimia; Wenqing Cai; Junko Sawada; Masanobu Komatsu; Joseph J Boyle; Bin Zhou; Pilar Ruiz-Lozano; Mark Mercola Journal: Cardiovasc Res Date: 2015-06-08 Impact factor: 10.787