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Embryonic central nervous system angiogenesis does not involve blood‐borne endothelial progenitors
Author(s) -
Kurz Haymo,
Korn Johannes,
Eggli Peter S.,
Huang Ruijin,
Christ Bodo
Publication year - 2001
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.1066
Subject(s) - biology , embryonic stem cell , angiogenesis , central nervous system , neuroscience , progenitor cell , progenitor , microbiology and biotechnology , stem cell , cancer research , genetics , gene
We asked, whether, in the blood of avian embryos, endothelial precursor cells circulate that actually contribute to the growing vascular system in and around the central nervous system (CNS). We compared the morphology and distribution of QH1‐positive cells after transplantation of quail paraxial mesoderm, after blood transfusion, in quail‐chick parabiosis, or after quail bone‐marrow transplantation. After head mesoderm transplantation from quail to chick, we observed sprouting endothelial cells (ECs), capillary tube formation, and chimeric endothelial lining of large arteries in the host brain. These QH1‐positive quail cells showed EC morphologies that demonstrated three different aspects of CNS angiogenesis: invasion by means of filopodia, clonal proliferation and tube formation, and integration into preexisting EC layers. After blood transfusion or in chick‐quail parabiosis, blood‐borne QH1+ cells were found in the lumen of but not integrated into the wall of the host vascular system. Neither were QH1+ cells observed in the capillary walls of parabiotic chick chorioallantoic membranes. In both cases, the quail cells showed typical macrophage morphology. In chicks that had received quail bone marrow transplants onto their chorioallantoic membranes, QH1+ cells with macrophage, but not EC shape were occasionally seen near the inoculation site. We conclude that (1) blood‐borne cells do not become ECs or directly contribute to angiogenesis inside, or in vascular plexuses around the CNS during embryonic development; (2) blood‐borne cells do not contribute to the intraneural macrophage population of the embryonic CNS. J. Comp. Neurol. 436:263–274, 2001. © 2001 Wiley‐Liss, Inc.