Expanding roles for alpha 4 integrin and its ligands in development.
Cell Adhes Commun
; 2(1): 27-43, 1994 Apr.
Article
em En
| MEDLINE
| ID: mdl-7526952
ABSTRACT
Interaction of alpha 4 integrins with vascular cell adhesion molecule-1 (VCAM-1) is classically important for immune function. However, we found recently that these receptors have a second role, in embryogenesis, where they mediate cell-cell interactions that are important for skeletal muscle differentiation. Here, we present evidence of an expanding role for these receptors in murine development. alpha 4 and VCAM-1 were found at embryonic sites of hematopoiesis, suggesting a role for these receptors during embryogenesis that parallels their hematopoietic function in adult bone marrow. During angiogenesis in the lung, alpha 4 and VCAM-1 were found on mesenchyme that gives rise to vascular endothelium and smooth muscle. alpha 4 persisted on the smooth muscle and the endothelium of newly forming vessels where it colocalized with its extracellular matrix ligand, fibronectin (FN). These patterns suggest several roles for alpha 4 integrins and their ligands in angiogenesis. alpha 4 was also found on neural crest derivatives where it colocalized with FN. alpha 4 was expressed selectively on cells in the dorsal root ganglia it was apparent along ventral projections, but absent from dorsal projections, suggesting that alpha 4 integrins could be involved in defining neuronal fates. Although VCAM-1 was not expressed on most neural crest derivatives, it was found in the neural crest-derived outflow tract of the embryonic heart, where it colocalized with alpha 4. These results imply that alpha 4 integrins and their ligands could be important for migration or differentiation of neural crest. alpha 4 was also expressed on embryonic retina and FN was found on inductive mesenchyme surrounding the eye, suggesting a role for these proteins in eye development. Finally, based on their patterns of expression, we conclude that VCAM-1 only participates in a subset of interactions involving alpha 4 integrins, whereas FN appears to be the more general ligand.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Envelhecimento
/
Endotélio Vascular
/
Moléculas de Adesão Celular
/
Integrinas
/
Fibronectinas
/
Desenvolvimento Embrionário e Fetal
/
Músculo Liso Vascular
Limite:
Animals
/
Pregnancy
Idioma:
En
Revista:
Cell Adhes Commun
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
1994
Tipo de documento:
Article