RT Journal Article T1 Characterization of a Fetal Liver Cell Population Endowed with Long-Term Multiorgan Endothelial Reconstitution Potential. A1 Cañete, Ana A1 Comaills, Valentine A1 Prados, Isabel A1 Castro, Ana Maria A1 Hammad, Seddik A1 Ybot-Gonzalez, Patricia A1 Bockamp, Ernesto A1 Hengstler, Jan G A1 Gottgens, Bertie A1 Sanchez, Maria Jose K1 Endothelial reconstitution K1 Fetal liver K1 Hematopoietic progenitors K1 Newborn transplantation K1 Progenitor cells AB Stable reconstitution of vascular endothelial beds upon transplantation of progenitor cells represents an important challenge due to the paucity and generally limited integration/expansion potential of most identified vascular related cell subsets. We previously showed that mouse fetal liver (FL) hemato/vascular cells from day 12 of gestation (E12), expressing the Stem Cell Leukaemia (SCL) gene enhancer transgene (SCL-PLAP+ cells), had robust endothelial engraftment potential when transferred to the blood stream of newborns or adult conditioned recipients, compared to the scarce vascular contribution of adult bone marrow cells. However, the specific SCL-PLAP+ hematopoietic or endothelial cell subset responsible for the long-term reconstituting endothelial cell (LTR-EC) activity and its confinement to FL developmental stages remained unknown. Using a busulfan-treated newborn transplantation model, we show that LTR-EC activity is restricted to the SCL-PLAP+ VE-cadherin+ CD45- cell population, devoid of hematopoietic reconstitution activity and largely composed by Lyve1+ endothelial-committed cells. SCL-PLAP+ Ve-cadherin+ CD45- cells contributed to the liver sinusoidal endothelium and also to the heart, kidney and lung microvasculature. LTR-EC activity was detected at different stages of FL development, yet marginal activity was identified in the adult liver, revealing unknown functional differences between fetal and adult liver endothelial/endothelial progenitors. Importantly, the observations that expanding donor-derived vascular grafts colocalize with proliferating hepatocyte-like cells and participate in the systemic circulation, support their functional integration into young livers. These findings offer new insights into the engraftment, phonotypical, and developmental characterization of a novel endothelial/endothelial progenitor cell subtype with multiorgan LTR-EC activity, potentially instrumental for the treatment/genetic correction of vascular diseases. PB Oxford University Press YR 2016 FD 2016-09-28 LK http://hdl.handle.net/10668/10431 UL http://hdl.handle.net/10668/10431 LA en NO Cañete A, Comaills V, Prados I, Castro AM, Hammad S, Ybot-Gonzalez P, et al. Characterization of a Fetal Liver Cell Population Endowed with Long-Term Multiorgan Endothelial Reconstitution Potential. Stem Cells. 2017 Feb;35(2):507-521. NO We thank the technical support from Tamara Garcia and the FACS, microscopy and animal facilities at the CABD. We thank David Hills, Beatriz Arteta, Anabel Rojas, James Castelli-Gair-Hombria and Rosario Rodriguez-Griñolo for reagents , protocols , critical reading of the manuscript and advise on statistical analysis . This work was funded through grants BFU2010-15801 and CSD-2007-00008 from the Spanish Ministry of Economy and Competitiveness and grant CVI-295 from Junta de Andalucía Regional Government to MJS and the European Regional Development Funds for the CABD equipment . Work in the Gottgens group is supported by core infrastructure funding from the Wellcome Trust and MRC to the Wellcome Trust and MRC Cambridge Stem Cell Institute DS RISalud RD Apr 9, 2025