Origin of endothelial cells from mesothelial-derived mesenchymal cells in the liver of avian embryos
Published: 1 June 2001
R Munoz-Chapuli, R Carmona, M Gonzalez-Iriarte, JM Perez-Pomares, D Macias, G Atencia, MJ Aranda
Univ Malaga, Fac Ciencias, Dept Anim Biol, Malaga, Spain; Med Univ S Carolina, Dept Cell Biol & Anat, Charleston, SC USA
We have tested the hypothesis of an origin of mesenchyme from the coelomic mesothelium of the developing avian liver and the differentiation of sinusoidal endothelial cells from mesothelial-derived mesenchymal cells. Our results have shown that 1) Mesothelial cells of the developing liver and the submesothelial mesenchymal cells are simultaneously cytokeratin (CK) and vimentin (VIM) immunoreactive between HH18 and HH28.2) A number of early sinusoidal cells are also CK immunoreactive. In the quail, CK colocalizes with the vascular marker QH1 in these cells. 3) In late embryos (>HH30), only the mesothelium remains CK+. 4) Mesothelial and submesothelial mesenchymal cells express the transcription factors Slug and WT1, both related to the epithelial-mesenchymal transition. 5) When the surface mesothelium was stained in vivo with CCFSE, a carboxyfluorescein derivative, isolated sinusoidal cells were labelled after 24-48 h, These observations suggest that mesenchymal cells originate from the coelomic mesothelium of the developing liver and differentate into endothelial cells of the hepatic sinusoids.