In situ expression of beta 1, beta 3 and beta 4 integrin subunits in non-neoplastic endothelium and vascular tumours

Virchows Arch. 1994;425(4):375-84. doi: 10.1007/BF00189575.

Abstract

Endothelial cells play an important role in adhesive interactions between circulating cells and extracellular matrix proteins. In vitro studies have shown that many of these processes are mediated by a superfamily of alpha beta heterodimeric transmembrane glycoproteins called integrins. The distribution patterns of beta 1, beta 3 and beta 4 integrin subunits in endothelial cells (EC) in situ were examined immunohistochemically on serial frozen sections of a wide range of non-neoplastic tissues and of vascular tumours, both benign and malignant. Expression of the beta 1 subunit was a constitutive feature of EC. Among the beta 1-associated alpha subunits, alpha 5 and alpha 6 were broadly distributed in EC, irrespective of vessel size and microenvironment. The alpha 3 subunit displayed intermediate levels of expression with a slight preference for small vessel EC. Presence of alpha 1 was confined to EC of capillaries and venules/small veins. Expression of alpha 2 in EC was inconsistent. With rare exceptions, the alpha 4 chain was absent in EC. The beta 3 and alpha v subunits were expressed in most EC, though not always concomitantly. In contrast to the beta 1 chain, however, these integrin subunits were absent in EC of glomerular capillaries and were expressed variably in sinusoidal EC. The beta 4 chain was evenly present in the great majority of EC, except for those of large vessels. In vascular tumours, the patterns of beta 1 and alpha 1 to alpha 6 subunit expression generally corresponded to those found in their non-neoplastic counterparts. Expression of beta 3, alpha v and beta 4 chains, however, decreased in neoplasia, especially in angiosarcomas. These data show that EC dispose of broad and at the same time differential repertoires of integrin subunits that presumably reflect vessel-type associated functional differences among these cells. In vascular tumours, the orthologous distribution patterns of beta 1 and alpha 1 to alpha 6 chains are conserved in most instances while the amounts of beta 3, alpha v and beta 4 subunits expressed in EC tend to decrease in the course of malignant transformation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal
  • Arterioles
  • Capillaries
  • Cerebral Cortex / blood supply
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / metabolism*
  • Endothelium, Vascular / pathology
  • Glomus Tumor / metabolism
  • Glomus Tumor / pathology*
  • Hemangioma / metabolism
  • Hemangioma / pathology*
  • Hemangioma, Cavernous / metabolism
  • Hemangioma, Cavernous / pathology
  • Hemangiosarcoma / metabolism
  • Hemangiosarcoma / pathology*
  • Humans
  • Immunohistochemistry
  • Integrin beta1
  • Integrin beta3
  • Integrin beta4
  • Integrins / analysis
  • Integrins / biosynthesis*
  • Organ Specificity
  • Venules

Substances

  • Antibodies, Monoclonal
  • Integrin beta1
  • Integrin beta3
  • Integrin beta4
  • Integrins