Publisher Correction: High mitogenic stimulation arrests angiogenesis

The original version of this Article contained errors in Fig. 8. In panel a, the labels ‘VEGF’, ‘Notch’, ‘p21’, and ‘P-ERK’ were inadvertently omitted. This has been corrected in the PDF and HTML versions of the Article

Dual ifgMosaic: A Versatile Method for Multispectral and Combinatorial Mosaic Gene-Function Analysis

Improved methods for manipulating and analyzing gene function have provided a better understanding of how genes work during organ development and disease. Inducible functional genetic mosaics can be extraordinarily useful in the study of biological systems; however, this experimental approach is still rarely used in vertebrates. This is mainly due to technical difficulties in the assembly of large DNA constructs carrying multiple genes and regulatory elements and their targeting to the genome. In addition, mosaic phenotypic analysis, unlike classical single gene-function analysis, requires clear labeling and detection of multiple cell clones in the same tissue. Here, we describe several methods for the rapid generation of transgenic or gene-targeted mice and embryonic stem (ES) cell lines containing all the necessary elements for inducible, fluorescent, and functional genetic mosaic (ifgMosaic) analysis. This technology enables the interrogation of multiple and combinatorial gene function with high temporal and cellular resolution.This work was supported by grants to the PI R.B. from the Spanish Ministry of Economy, Industry and Competitiveness (SAF2013-44329-P, SAF2013-42359-ERC, and RYC-2013-13209) and European Research Council (ERC-2014-StG - 638028). S.P.-Q., M.F.-C., and I.G.-G. were supported by PhD fellowships from Fundacion La Caixa (CX-SO-2013-02, CX\_E-2015-01, and CX-SO-16-1, respectively). W.L. by a FP7-PEOPLE-2012-COFUND GA600396 postdoctoral contract. We thank Simon Bartlett for English editing, Ralf H. Adams for sharing the Cdh5(PAC)-CreERT2 mice, Jose Luis de La Pompa for comments throughout the project and for sharing the Tie2-Cre mice, Gonzalo Gancedo for the help with the mouse colony, Valeria Caiolfa for the help with the microscopy, and all the members of the CNIC gene targeting, transgenesis, cellomics, and microscopy units. The CNIC is supported by MEIC/MINECO and the Pro CNIC Foundation and is a Severo Ochoa Center of Excellence (SEV-2015-0505).S

Regulation of enfothelial cell cycle dynamics by Notch during angiogenesis

The formation of new blood vessels by angiogenesis requires the precise coordination of endothelial cell differentiation, proliferation, migration and maturation to ensure that a proper vasculature is formed to satisfy the metabolic needs of the surrounding tissue. The Notch signaling pathway is a critical regulator of endothelial cell biology, participating in different processes of blood vessel formation from tipTcell specification to arterioTvenous differentiation and blood vessel stabilization. Inhibition of this pathway during angiogenesis has been associated with increased proliferation of endothelial cells. However, this seemingly antiproliferative effect of Notch activation does not adjust well to the current tipT stalk cell model of molecular control of angiogenesis, in which proliferative stalk cells are defined as having higher Notch activity. In this work we have tried to resolve this apparent paradox by characterizing in detail the effects of Notch on endothelial cell proliferation In vivo. We have used different pharmacological and classical genetic approaches in combination with newly developed mosaic genetic tools to evaluate, with high spatioTtemporal resolution, endothelial cell cycle dynamics. We have found that physiological Notch activation is required for maintaining endothelial cell proliferation by repressing excessive activation of proTproliferative molecular mechanism. Inhibition of Notch activity induces and hyperproliferative response that is partially dependent on ERK activation. This response is, however, not sustained in time and leads to proliferative arrest, partially mediated by ERK overactivation and p21 upregulation. This cellTcycle arrest is associated with an increase in the expression of genes characteristic of sprouting tip cells. Thus, Notch can control a mechanism to differentiate between a proliferative and migratory cellular response. Comparative trancriptomics revealed new putative NotchTrepressed genes that promote cell cycle progression like Myc and Odc1. Functional analysis of these genes showed their absolute requirement for normal endothelial cell proliferation

Regulation of endothelial cell cycle dynamics by Notch during angiogenesis

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Bioquímica. Fecha de lectura: 13-07-2018The laboratory of Dr. Rui Benedito is supported by the following grants: From the Spanish Ministry of Economy, Industry and Competitiveness (SAF2013- 44329-P SAF2013- 42359-ERC and RYC-2013-13209). From the European Research Council (ERC-2014-StG-638028). Samuel Pontes was supported by a PhD fellowshipby the Fundacion La Caixa (CX-SO-2013-02) The CNIC is supported by the Ministerio de Economia ,Industria y Competitividad (MEIC) and The Pro CNIC Foundation ,and is a Severo Ochoa Center of Excellence (SEV-2015-0505) This work was performed under the direction of Dr. Rui Benedito´s laboratory in the Developmental Biology and Repair Department at the Spanish National Center for Cardiovascular Research (CNIC) in Madrid

High mitogenic stimulation arrests angiogenesis

High mitogenic stimuli have been suggested to promote endothelial cell proliferation and sprouting during angiogenesis. Here Pontes-Quero et al., by interfering with levels of VEGF and Notch signalling in single endothelial cells in vivo, find that high mitogenic stimuli instead arrest angiogenesis due to a bell-shaped dose-response to VEGF and MAPK activity that is counteracted by Notch and p21